JP2000347344A - Heat-developable image forming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the heat-developable ultracontrasty image forming material which is small in adverse effect on human bodies and environments and stable and extremely small in fog in the case of fluctuation of heat-development conditions and adapted to forming a printing plate by using a polyhalogen compound extremely small in volatility. SOLUTION: The heat-developable image forming material contains, on at least one same side of a support (a) a reducible silver salt, (b) a reducing agent, (c) a binder, and sensitive layer containing a photosensitive silver halide and (d) a polymer having repeating units derived from a monomer of a polyalogen compound represented by the formula in which Ht is an aryl or heterocyclic group; each of E1 and E2 is, independently, a halogen atom; W is an H atom or an electron withdrawing group; R is a substituent; (k) is an integer of 0-4; Q is an ethylenically unsaturated group or a group having such a group; (m) is 1, 2 or 3; (n) is 1 or 2; when (k), (m), and (k) is >=2, each of 2 or more groups may be same or different.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-developable image forming material. More specifically, the present invention relates to a heat-developable ultrahigh contrast image forming material suitable for printing plate making which has little adverse effect on the human body and the environment, is stable against fluctuations in heat development conditions, and has extremely small fog.

[0002]

2. Description of the Related Art There are many known photosensitive materials having a photosensitive layer on a support and forming an image by exposing the image. Among them, a technique for forming an image by thermal development is a system that can simplify environmental preservation and image forming means. In recent years, environmental preservation in the photoengraving field,
From the viewpoint of space saving, it is strongly desired to reduce the amount of processing waste liquid. There, you can use a laser scanner or a laser imagesetter to make the exposure more efficient,
There is a need for a technique relating to a photosensitive heat-developable material for photolithography that can form a sharp black image having high resolution and sharpness. These photosensitive heat-developable materials eliminate the use of solution-based processing chemicals, and can provide customers with a simpler heat-development system that does not damage the environment.

[0003] A method of forming an image by heat development is described in, for example, US Pat.
Morgan and B.A. "Thermal Proces Silver System (Thermally Proces)" by Shely
sed Silver Systems) A "(Imaging Processes and Materials
aterials) Neblette 8th edition, Sturge, V.E.
Walworth, A .; Shepp
Edited, page 2, 1969). Such photosensitive materials are prepared by dispersing a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in. The photosensitive material is stable at room temperature, but when heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image.

[0004] Fog is a major problem in photothermographic materials. Many studies have been made to reduce fog of silver halide light-sensitive materials for thermophotography. For example, US Pat. No. 3,589,903 discloses a mercury salt. In addition, U.S. Pat.No. 4,152,160 includes carboxylic acids such as benzene and phthalic acid, U.S. Pat.No.4,784,939 discloses benzoylbenzene compounds, U.S. Pat. 82
No. 0,617 discloses dicarboxylic acids and U.S. Pat. No. 4,626,500 discloses heteroaromatic carboxylic acids. U.S. Patent No.
No. 4,546,075; U.S. Pat.No. 4,756,999; U.S. Pat.
No. 2,885, U.S. Pat.No. 3,874,946 and U.S. Pat.
No. 5,982 discloses halogenated compounds. U.S. Pat. No. 5,028,523 discloses halogen atoms combined with halogen molecules or heteroatom rings. U.S. Pat.Nos. 4,103,312 and GB1502670 include palladium compounds, U.S. Pat. 4th, 2nd
No. 13,784, U.S. Pat.No. 4,245,033 and JP-A-51-2601
No. 9 is a sulfur compound, U.S. Patent No. Metal salt, JP-A-53-
JP-A-20923 and JP-A-53-19825 use a combination of a metal salt of thiosulfonic acid and sulfinic acid, JP-B-62-50810, JP-A-7-209797 and JP-A-9-43760 describe thiosulfonic acid esters. It has been disclosed. Also, JP-A-51-4
No. 2529 and JP-B-63-37368 disclose a disulfide compound.

[0005] JP-B No. 54-165, EP-605981A,
No. 631176A, U.S. Pat.No. 4,546,075, U.S. Pat.
999, U.S. Patent No. 4,452,885, U.S. Patent No. 3,874,946
No. 3,955,982 disclose polyhalogenated compounds. However, these compounds have the drawback that the effect of preventing fogging is low, or the Dmax is reduced when the added amount is large, and the image storage stability after processing is deteriorated. In addition, there is a problem in that it evaporates out of the photosensitive material during thermal development and adversely affects the human body. Therefore, development of an antifoggant free of these problems has been desired. JP-A-10-197989 discloses the use of a polyhalogenated compound and a specific carboxylic acid derivative in combination to suppress fog, but does not disclose any volatilization during development. Further, fogging is not sufficient, and there is no mention of an effect of improving fluctuating development temperature or the like.

However, these compounds do not have sufficient fog-preventing ability, or if they are added in large amounts, Dmax
There is a drawback that the (highest density) decreases and the image storage stability after processing deteriorates, and a new antifoggant has been desired. Also, JP-A-51-26019, 57-26019
Nos. 207244, 60-207140, U.S. Pat. No. 2,910,377, U.S. Pat. No. 3,074,809.
JP-A-2-253838 discloses salicylic acid or a derivative thereof, but does not disclose any effect in a super-hard dry silver system.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art. That is, the present invention uses a polymer having a repeating unit derived from a monomer of a polyhalogen compound having almost no volatility, thereby having a small adverse effect on the human body and the environment, and suppressing fluctuations in heat development conditions. An object of the present invention is to provide a heat-developable ultrahigh contrast image forming material which is stable and suitable for printing plate making with extremely small fog.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a repeating unit derived from a monomer of a polyhalogen compound represented by the formula (1) It has been found that the use of a polymer having the formula (1) can provide an excellent heat-developable image-forming material having a desired effect, and have provided the present invention. That is,
The present invention, on at least one same surface of the support,
It contains (a) a reducible silver salt, (b) a reducing agent, (c) a binder, and (d) a polymer having a repeating unit derived from a monomer of the polyhalogen compound represented by the formula (1). A heat-developable image forming material is provided.

Embedded image [In the formula (1), Ht represents an aromatic ring group or a heterocyclic group, E ₁ and E ₂ each independently represent a halogen atom, and W represents a hydrogen atom or an electron-withdrawing group. R represents a substituent, and k represents an integer of 0 to 4. Q represents an ethylenically unsaturated group or a group having the same;
Represents an integer. n represents an integer of 1 or 2. When k, m and n represent an integer of 2 or more, the groups present in 2 or more may be the same or different. In a preferred embodiment, the heat-developable image-forming material of the present invention further comprises (e) photosensitive silver halide on the same surface. Preferably, in the above formula (1), E ₁ , E ₂ and W are bromine atoms. In a preferred embodiment, the heat-developable image forming material of the present invention further has (f) a super-high contrast agent on the same surface.

Preferably, the superhigh contrast agent is selected from the compounds represented by formulas (2), (3) and (4).

Embedded image [In the formula (2), R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (2), R ₁ and Z, R ₂ and R ₃ , R ₁ and R ₂ , and R ₃ and Z may be mutually bonded to form a cyclic structure. In equation (3),
R ₄ represents a substituent. In the formula (4), X and Y each independently represent a hydrogen atom or a substituent;
Each independently represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or a heterocyclic amino group. In the formula (4), X and Y, and A and B may be bonded to each other to form a cyclic structure. ]

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, embodiments and methods of the heat-developable image forming material of the present invention will be described in detail. The heat-developable image-forming material of the present invention comprises: (a) a reducible silver salt on at least one same surface of a support;
(B) a reducing agent, (c) a binder, and (d) a polymer having a repeating unit derived from a monomer of the polyhalogen compound represented by the formula (1). By using a polymer having a repeating unit derived from a monomer of the polyhalogen compound represented by the formula (1), heat fogging in the non-image area is suppressed and stable against fluctuations in heat development conditions. And volatility can be greatly reduced. Therefore, the heat-developable image-forming material of the present invention has a small adverse effect on the human body and the environment by using a polymer having a repeating unit derived from a monomer of a polyhalogen compound having little volatility, and has a low heat development property. This is a heat-developable ultra-high contrast image forming material that is stable to fluctuations in conditions and is suitable for printing plate making with extremely small fog.

First, the compound of the formula (1) used in the present invention will be described in detail. Equation (1) is shown below.

[0012]

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In the formula (1), E ₁ and E ₂ are each independently a halogen atom (fluorine, chlorine, bromine, iodine)
It is most preferred that both E ₁ and E ₂ are bromine atoms. In the formula (1), W is a hydrogen atom or an electron withdrawing group. The electron withdrawing group referred to here is
Hammett's substituent constant σ _p is a substituent that can take a positive value, specifically, for example, cyano group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, sulfamoyl group, alkylsulfonyl group, aryl Represents a sulfonyl group, a halogen atom, an acyl group, a heterocyclic group or the like. In the formula (1), W is preferably a hydrogen atom or a halogen atom, and most preferably a bromine atom.

In the formula (1), R represents a substituent. The substituent may be any generally known substituent, for example, a linear, branched or cyclic alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 12 carbon atoms). -8, for example, methyl, ethyl,
iso-propyl, tert-butyl, n-octyl,
tert-amyl, 1,3-tetramethylbutyl, cyclohexyl and the like. ), Alkenyl groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, for example, vinyl, allyl, 2-butenyl, 3-pentenyl and the like), alkynyl Groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 12,
It is particularly preferably 2 to 8, and examples include a propargyl group and a 3-pentynyl group. ), An aryl group (preferably having 6 to 30, more preferably 6 to 20, and particularly preferably 6 to 12; examples thereof include phenyl, p-methylphenyl, and naphthyl); and an amino group (preferably). Has 0 to 20, more preferably 0 to 10, and still more preferably 0 to 6 carbon atoms. Examples thereof include amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like, and an alkoxy group (preferably, It has from 1 to 20 carbon atoms, more preferably from 1 to 12, particularly preferably from 1 to 8, and includes, for example, methoxy, ethoxy, butoxy, etc., and an aryloxy group (preferably from 6 to 20, more preferably Is from 6 to 16, particularly preferably from 6 to 12, for example, phenyloxy, 2-naphthyloxy and the like.), An acyl group (preferably having 1 to 20 carbon atoms, Ri preferably 1 to 16, particularly preferably 1 to
12, for example, acetyl, benzoyl, formyl,
Pivaloyl and the like. ), An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 1
6, particularly preferably 2 to 12, for example, methoxycarbonyl, ethoxycarbonyl and the like. ),
Aryloxycarbonyl group (preferably having 7 to 2 carbon atoms)
It is 0, more preferably 7 to 16, particularly preferably 7 to 10, and examples include phenoxycarbonyl. ), An acyloxy group (preferably having 1 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy and benzoyloxy, etc.), and an acylamino group (preferably having 1 carbon atom). -20, more preferably 2-16, particularly preferably 2-10, for example, acetylamino, benzoylamino and the like.), Alkoxycarbonylamino group (preferably 2-20 carbon atoms, more preferably 2 carbon atoms) To 16, particularly preferably 2 to 12, for example, methoxycarbonylamino and the like.), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 16 carbon atoms). 12, for example, phenyloxycarbonylamino and the like), a sulfonylamino group (preferably having 1 to 20 carbon atoms, Ri is preferably 1 to 1
6, particularly preferably 1 to 12, for example, methanesulfonylamino, benzenesulfonylamino and the like. ), A sulfamoyl group (preferably having 0 to 2 carbon atoms)
0, more preferably 0 to 16, particularly preferably 0 to 12, for example, sulfamoyl, methylsulfamoyl,
Dimethylsulfamoyl, phenylsulfamoyl and the like can be mentioned. ), A carbamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16, particularly preferably 0 to 12 carbon atoms).
And examples thereof include carbamoyl, diethylcarbamoyl, phenylcarbamoyl and the like. ), Ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to
16, particularly preferably 1 to 12, for example, ureido,
Methyl ureide, phenyl ureide and the like can be mentioned. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 to 12, and examples thereof include methylthio and ethylthio).
An arylthio group (preferably having 6 to 20, more preferably 6 to 16, particularly preferably 6 to 12, and examples thereof include phenylthio, etc.) and a sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably Is 1 to 16, particularly preferably 1 to 12, and examples thereof include mesyl, tosyl, phenylsulfonyl, mesitylsulfonyl and the like, and a sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16). And particularly preferably 1 to 12, for example, methanesulfinyl, benzenesulfinyl and the like.), A phosphoramide group (preferably having 1 carbon atom)
-20, more preferably 1-16, particularly preferably 1-12, for example, diethylphosphoramide, phenylphosphoramide and the like. ), Hydroxy, mercapto, halogen (eg, fluorine, chlorine, bromine, iodine), cyano, sulfo, carboxy, nitro, hydroxam, sulfino, sulfino, hydrazino, sulfonylthio Thiosulfonyl group, heterocyclic group (for example, imidazolyl, pyridyl, furyl, piperidyl, morpholinyl and the like), disulfide group and the like. k is an integer of 0 to 4 and k ≧ 2
In the above case, a plurality of Rs may be the same or different.

These substituents may be further substituted, and a salt-forming group may form a salt. These substituents may be bonded to each other, and preferably form a 5- to 7-membered non-aromatic or aromatic carbon ring. Further, the ring may be substituted with other substituents.

Ht represents an aromatic ring group or a heterocyclic group. The aromatic ring group represented by Ht in the formula (1) is preferably a monocyclic or condensed aryl group having 6 to 30 carbon atoms,
More preferably, it is a 6-20 monocyclic or condensed aryl group, for example, phenyl, naphthyl and the like, and particularly preferably a phenyl group. The aromatic ring group represented by Ht may have a substituent, and any substituent may be used as long as the substituent does not adversely affect photographic performance. For example, a halogen atom (fluorine atom , A chlorine atom, a bromine atom, or an iodine atom), an alkyl group (including an aralkyl group, a cycloalkyl group, an active methine group, etc.), an alkenyl group, an alkynyl group, an aryl group, and a heterocyclic group (N-substituted nitrogen-containing heteroatom). A heterocyclic group containing a quaternized nitrogen atom (eg, a pyridinio group), an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a carboxy group or a salt thereof, an imino group, an N atom Imino group, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, alkoxy group (ethyleneoxy group or Piren'okishi containing repeating group containing group units), an aryloxy group, a heterocyclic oxy group, an acyloxy group,
(Alkoxy or aryloxy), carbamoyloxy group, sulfonyloxy group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, Thiosemicarbazide group, hydrazino group, quaternary ammonium group, (alkyl or aryl) sulfonyluureido group, nitro group, (alkyl, aryl, or heterocycle) thio group, acylthio group, (alkyl or aryl) sulfonyl group, (alkyl Or an aryl) sulfinyl group, a sulfo group or a salt thereof, a sulfamoyl group, a phosphoryl group, a group having a phosphoric amide or a phosphoric ester structure, and a silyl group. These substituents may be further substituted with these substituents.

Particularly preferably, the substituent of the aromatic ring group represented by Ht in the formula (1) is an alkyl group, an alkoxy group,
An aryloxy group and a halogen atom. In the formula (1), the heterocyclic group represented by Ht is a 5- to 7-membered saturated or unsaturated heterocyclic ring containing at least one N, O or S atom. Or a condensed ring with another ring may be formed. Examples of the heterocyclic group represented by Ht include a pyridyl group, a pyrazinyl group, a pyrimidyl group, a benzothiazole group, a benzimidazole group, a thiadiazolyl group, a quinolyl group, and an isoquinolyl group. These may have a substituent, and examples thereof include the same groups as the substituents of the aromatic ring group represented by Ht, and the preferable range is also the same. Ht in the formula (1) is preferably an aryl group, particularly preferably a phenyl group.

Q represents an ethylenically unsaturated group or a group having the same, and is preferably represented by the following general formula (5).

[0019]

Embedded image

Where R_FiveIs a hydrogen atom, a carboxy group or
Represents an alkyl group (eg, methyl group, ethyl group, etc.)
However, this alkyl group may have a substituent,
Examples of the group include a halogen atom and a carboxyl group.
Can be R_FiveOf the carboxyl group and the substituent represented by
The ruboxyl group may form a salt. Where J₁and
J_TwoRepresents a divalent linking group, and the divalent linking group
Are, for example, -NHCO-, -CONH-, -C
OO-, -OCO-, -SCO-, -COS-, -O
-, -S-, -SO-, -SO_Two-And so on. X₁, X
_TwoEach represents a divalent hydrocarbon group;
Examples of the group include an alkylene group (eg, methylene
Group, propylene group, etc.), arylene group (for example,
Arylene group (eg, phenylene group)
Alkylene arylene group (for example,
Or an arylene alkylene
Group (for example, phenylenemethylene group, etc.)
You. k₁, M₁, K _Two, M_TwoRepresents 0 or 1, respectively.

In the formula (1), m is an integer of 1 to 3,
When m ≧ 2, a plurality of Qs may be the same or different and may combine with each other to form a ring. n is an integer of 1 or 2, and when n = 2, a plurality of substituents may be the same or different.

Hereinafter, specific examples of the polyhalogen compound represented by the formula (1) will be shown, but the present invention is not limited thereto.

[0023]

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[0024]

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[0025]

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[0026]

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Next, specific examples of the copolymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) will be described, but the present invention is not limited thereto.

[0028]

[Table 1]

The polymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) used in the present invention may be used alone or in combination of two or more. Good. Further, in addition to the above-mentioned ones,
-160167, Japanese Patent Application No. 10-2922863, Japanese Patent Application No. 1
0-292864 and polyhalogen compounds described in JP-A-10-339934 may be used in combination. The compounds having an ethylenically unsaturated group and their polymers can be easily synthesized by a method described in a textbook such as New Experimental Chemistry Course (Maruzen). Hereinafter, synthesis examples of the polymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) used in the present invention are shown, but the present invention is not limited thereto.

Synthesis example

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4-vinylbenzenesulfonylacetic acid sodium salt (15 g) was dissolved in 30 ml of water and heated to 90 ° C. 0.15 g of V-50 as a radical initiator was added three times at hourly intervals. After further heating and stirring for 2 hours, the mixture was added to a dilute aqueous hydrochloric acid solution and stirred, whereby a white precipitate was obtained. This solid was collected by filtration and dried to give sodium poly-4-vinylbenzenesulfonylacetate quantitatively. This polymer (15 g) was mixed with water (200 ml), 1,
To a mixture of 4-dioxane (140 ml) was added NaH
Add CO ₃ (9.0 g) and stir to obtain a homogeneous solution. This solution was added to an aqueous NaOBr solution (0.25 mol
Dropping in l) produces a solid. The heterogeneous reaction solution was heated at 40 ° C. for 5 hours, and the generated solid was collected by filtration and washed with water. The solid was dried to obtain the desired poly 4-vinylbenzene tribromomethyl sulfone (21 g).

The polymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) may be water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol). ), Ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. Also, by an already well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone are dissolved and mechanically emulsified and dispersed. An object can be prepared and used. Alternatively, the powder can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Manton-Gaulin, a microfluidizer, or an ultrasonic wave by a method known as a solid dispersion method.

The polymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) is a layer on the image forming layer side with respect to the support, that is, the image forming layer or this layer side. May be added to any other layer, but is preferably added to the image forming layer or a layer adjacent thereto. The polymer compound having a repeating unit derived from the monomer of the polyhalogen compound represented by the formula (1) is preferably 5 × 10 ⁻⁵ to 1 × 10 5 in terms of a coating amount per m ^{2 of} the image forming material. ^-2 mol / m ² , more preferably 1 × 10 ^{−4 to} 5 × 10 ⁻³ mol / m ² . These compounds may be used alone or in combination of two or more.

The heat-developable image forming material of the present invention contains a substituted alkene derivative, a substituted isoxazole derivative and a specific acetal compound represented by the following formulas (2) to (4) as a super-high contrast agent. Is preferred. Equation (2), Equation
(3) and Equation (4) will be described.

[0035]

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In the equation (2), R₁, R_Two, R_ThreeEach
Each independently represents a hydrogen atom or a substituent, and Z represents an electron-withdrawing property.
Represents a group or a silyl group. In the formula (2), R₁And Z, R_Two
And R _Three, R₁And R_TwoOr R_ThreeAnd Z are joined together
An annular structure may be formed. In the formula (3), R
_FourRepresents a substituent. In equation (4), X and Y are respectively
A and B independently represent a hydrogen atom or a substituent,
Independently, an alkoxy group, an alkylthio group, an alkylamido
Group, aryloxy group, arylthio group, anilino
Group, heterocyclic oxy group, heterocyclic thio group, or hetero
Represents a ring amino group. In equation (4), X and Y or A
And B may combine with each other to form a cyclic structure
No.

The compound represented by the formula (2) will be described in detail. When R ₁ , R ₂ , and R ₃ represent a substituent, examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (an aralkyl group, a cycloalkyl group, Active methine group, etc.), alkenyl group, alkynyl group, aryl group, heterocyclic group (including N-substituted nitrogen-containing heterocyclic group), heterocyclic group containing quaternized nitrogen atom (eg, pyridinio group) ), Acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, imino group, imino group substituted with N atom, thiocarbonyl group, sulfonylcarbamoyl group, acylcarbamoyl group, sulfamoylcarbamoyl Group, carbazoyl group, oxalyl group, oxamoyl group, cyano group, thiocarbamoyl group, hydroxy group Or its salt, an alkoxy group (including a group containing an ethyleneoxy group or a propyleneoxy group unit repeatedly), an aryloxy group, a heterocyclic oxy group, an acyloxy group, an (alkoxy or aryloxy) carbonyloxy group, a carbamoyloxy group, Sulfonyloxy group, amino group, (alkyl, aryl, or heterocycle) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy)
Carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, 4
Grade ammonio group, oxamoylamino group, (alkyl or aryl) sulfonyluureido group, acylureido group, acylsulfamoylamino group, nitro group, mercapto group, (alkyl, aryl, or heterocycle)
Thio group, acylthio group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group, acylsulfamoyl group, sulfonylsulfamoyl group or a salt thereof, phosphoryl group, phosphorus Examples include groups having an acid amide or phosphate structure, silyl groups, stannyl groups, and the like. These substituents may be further substituted with these substituents.

The electron-withdrawing group represented by Z in the formula (2) is a substituent whose Hammett's substituent constant σ _p can take a positive value. Carbonyl group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with an N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom,
A perfluoroalkyl group, a perfluoroalkaneamide group, a sulfonamide group, an acyl group, a formyl group, a phosphoryl group, a carboxy group (or a salt thereof), a sulfo group (or a salt thereof), a heterocyclic group, an alkenyl group, an alkynyl group, Examples include an acyloxy group, an acylthio group, a sulfonyloxy group, and an aryl group substituted with these electron-withdrawing groups. Here, the heterocyclic group is a saturated or unsaturated heterocyclic group, for example, a pyridyl group, a quinolyl group,
Examples thereof include a quinoxalinyl group, a pyrazinyl group, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group, a hydantoin-1-yl group, a succinimide group, and a phthalimido group. The electron-withdrawing group represented by Z in the formula (2) may further have a substituent, and as the substituent, R ₁ , R ₂ and R _{3 in} the formula (2) are the same as the substituents. The same substituents as the substituents which may be present at the time of expression are exemplified.

In the formula (2), R ₁ and Z, R ₂ and R ₃ , R ₁ and R ₂ , or R ₃ and Z may be bonded to each other to form a cyclic structure. The cyclic structure is
It is a non-aromatic carbon ring or a non-aromatic hetero ring.
Next, a preferred range of the compound represented by the formula (2) will be described. Preferable examples of the silyl group represented by Z in the formula (2) include a trimethylsilyl group, a t-butyldimethylsilyl group, a phenyldimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, and a trimethylsilyldimethylsilyl group. . In the formula (2), the electron-withdrawing group represented by Z is preferably a total of 0 to 30 carbon atoms.
The following groups, namely, cyano group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, thiocarbonyl group, imino group, imino group substituted with N atom, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group , Perfluoroalkyl group,
An acyl group, a formyl group, a phosphoryl group, an acyloxy group, an acylthio group, or a phenyl group substituted with any electron-withdrawing group, and more preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, an imino group, and a sulfamoyl group. Group, alkylsulfonyl group, arylsulfonyl group, acyl group, formyl group, phosphoryl group, trifluoromethyl group, or a phenyl group substituted with any electron-withdrawing group, and particularly preferably a cyano group, a formyl group, It is an acyl group, an alkoxycarbonyl group, an imino group or a carbamoyl group.

The group represented by Z in the formula (2) is more preferably an electron-withdrawing group. In the formula (2), the substituent represented by R ₁ , R ₂ and R ₃ is preferably a total of 0 carbon atoms.
To 30 groups, specifically, groups having the same meaning as the electron-withdrawing group represented by Z in the above formula (2), and an alkyl group, a hydroxy group (or a salt thereof), and a mercapto group (or a salt thereof) An alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alkylamino group, an arylamino group, a heterocyclic amino group, a ureido group, an acylamino group, a sulfonamide group, Or a substituted or unsubstituted aryl group. Further, in the formula (2), R ₁ is preferably an electron-withdrawing group, an aryl group, an alkylthio group, an alkoxy group, an acylamino group, a hydrogen atom or a silyl group.

When R ₁ represents an electron-withdrawing group, preferably the following groups having a total of 0 to 30 carbon atoms, ie, a cyano group, a nitro group, an acyl group, a formyl group, an alkoxycarbonyl group,
An aryloxycarbonyl group, a thiocarbonyl group, an imino group, an imino group substituted with an N atom, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a sulfamoyl group, a trifluoromethyl group, a phosphoryl group, a carboxy group (or a salt thereof), Or a saturated or unsaturated heterocyclic group, and a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a sulfamoyl group, a carboxy group (or a salt thereof) Or a saturated or unsaturated heterocyclic group. Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a saturated or unsaturated heterocyclic group.

When R ₁ represents an aryl group, it is preferably a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms in total, and the substituent may be any substituent.
Among them, an electron-withdrawing substituent is preferable. In formula (2), R ₁ is more preferably an electron-withdrawing group or an aryl group. In the formula (2), the substituents represented by R ₂ and R ₃ are preferably specific examples of the above-mentioned formula (2)
A group having the same meaning as the electron-withdrawing group represented by Z, an alkyl group,
Hydroxy group (or salt thereof), mercapto group (or salt thereof), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group, alkylamino group, anilino group, hetero Examples include a cyclic amino group, an acylamino group, and a substituted or unsubstituted phenyl group.

In formula (2), R ₂ and R ₃ are more preferably when one of them is a hydrogen atom and the other is a substituent. The substituent is preferably an alkyl group, a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group. Group, alkylamino group, anilino group,
Heterocyclic amino group, acylamino group (particularly perfluoroalkaneamide group), sulfonamide group, substituted or unsubstituted phenyl group, or a heterocyclic group, more preferably a hydroxy group (or a salt thereof), a mercapto group ( Or a salt thereof), an alkoxy group, an aryloxy group,
Heterocyclic oxy group, alkylthio group, arylthio group,
A heterocyclic thio group or a heterocyclic group, particularly preferably a hydroxy group (or a salt thereof), an alkoxy group, or a heterocyclic group.

In the formula (2), Z and R ₁ , or alternatively, R ₂
It is also preferred that and R ₃ form a cyclic structure. The cyclic structure formed in this case is a non-aromatic carbocyclic ring or a non-aromatic hetero ring, preferably a 5- to 7-membered cyclic structure having a total carbon number including a substituent of 1 to 4
0, more preferably 3 to 30. Among the compounds represented by the formula (2), one of the more preferable ones is that Z is a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group,
Represents an imino group or a carbamoyl group, R ₁ represents an electron-withdrawing group or an aryl group, one of R _{2 and} R ₃ is a hydrogen atom, and the other is a hydroxy group (or a salt thereof), a mercapto group (or Salt), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group,
A compound representing an arylthio group, a heterocyclic thio group, or a heterocyclic group.

Further, among the compounds represented by the formula (2),
One particularly preferred is Z and R ₁Is non-aromatic 5
Having a 7 to 7 membered cyclic structure,_TwoOr R_ThreeThroat
One is a hydrogen atom and the other is a hydroxy group (or
Salt), mercapto group (or salt thereof), alkoxy
Group, aryloxy group, heterocyclic oxy group, alkylthio
O, arylthio, heterocyclic thio, or hetero
It is a compound that represents a ring group. At this time, R₁With non-aromatic
Z which forms a cyclic structure of
Yl, oxycarbonyl, thiocarbonyl, sulf
A honyl group and the like are preferable.₁As an acyl group,
Carbamoyl group, oxycarbonyl group, thiocarbonyl
Group, sulfonyl group, imino group, imino substituted with N atom
Groups, acylamino groups, carbonylthio groups and the like are preferred.

Next, the compound represented by the formula (3) will be described. As the substituent represented by R ₄ in the formula (3),
Examples are the same as those described for the substituents of R _{1 to} R _{3 in} the formula (2). In formula (3), the substituent represented by R ₄ is preferably an electron-withdrawing group or an aryl group. When R ₄ represents an electron-withdrawing group, preferably the following groups having a total carbon number of 0 to 30, that is, a cyano group, a nitro group, an acyl group, a formyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl Group, arylsulfonyl group, carbamoyl group, sulfamoyl group,
A trifluoromethyl group, a phosphoryl group, an imino group, or a saturated or unsaturated heterocyclic group, and further a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group And a heterocyclic group are preferred. Particularly preferably, a cyano group, a formyl group, an acyl group,
It is an alkoxycarbonyl group, a carbamoyl group, or a heterocyclic group.

[0047] When R ₄ represents an aryl group, preferably a total carbon number of 0 to 30, a substituted or unsubstituted phenyl group, the substituent, R _1, R _2, R ₃ of formula (2) When represents a substituent, the same as those described as the substituent can be mentioned. In the formula (3), R ₄ is particularly preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group,
A heterocyclic group or a substituted or unsubstituted phenyl group, most preferably a cyano group, a heterocyclic group, or an alkoxycarbonyl group.

Next, the compound represented by formula (4) will be described in detail. In the formula (4), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent:
Represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group. X and Y or A and B may be bonded to each other to form a cyclic structure.

As the substituents represented by X and Y in the formula (4), the same as those described for the substituents R _{1 to} R _{3 in} the formula (2) can be mentioned. Specifically, alkyl groups (including perfluoroalkyl groups, trichloromethyl groups, etc.), aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, alkenyl groups, alkynyl groups, acyl groups, formyl groups, alkoxy groups Carbonyl group, aryloxycarbonyl group, imino group, imino group substituted with an N atom, carbamoyl group, thiocarbonyl group, acyloxy group, acylthio group, acylamino group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, phosphoryl group, carboxy Group (or its salt), sulfo group (or its salt), hydroxy group (or its salt), mercapto group (or its salt), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, hetero group Ring thio group, amino group, alkylami Group, anilino group, heterocyclic amino group, a silyl group, and the like. These groups may further have a substituent. X and Y may be bonded to each other to form a cyclic structure. In this case, the cyclic structure formed includes:
It may be a non-aromatic carbon ring or a non-aromatic hetero ring.

The substituents represented by X and Y in the formula (4) are preferably groups having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and include a cyano group, an alkoxycarbonyl group, Aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group , An acylamino group, an acyloxy group, an acylthio group, a heterocyclic group, an alkylthio group, an alkoxy group, or an aryl group. In the formula (4), X and Y are more preferably a cyano group, nitro group, alkoxycarbonyl group, carbamoyl group, acyl group, formyl group, acylthio group, acylamino group, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, aryl Sulfonyl group, imino group,
An imino group, a phosphoryl group, a trifluoromethyl group, a heterocyclic group, or a substituted phenyl group substituted with an N atom, particularly preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group , Acyl group, acylthio group, acylamino group, thiocarbonyl group, formyl group, imino group, N
Examples include an imino group substituted with an atom, a heterocyclic group, and a phenyl group substituted with an arbitrary electron-withdrawing group.

It is also preferred that X and Y combine with each other to form a non-aromatic carbon ring or a non-aromatic hetero ring. At this time, the formed cyclic structure is preferably a 5- to 7-membered ring, and has a total carbon number of 1 to 40, more preferably 3 to
30 is preferred. X and Y forming a cyclic structure include an acyl group, a carbamoyl group, an oxycarbonyl group,
Preferred are a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted with an N atom, an acylamino group, a carbonylthio group and the like.

In the formula (4), A and B are each independently:
Represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group, which are bonded to each other to form a cyclic structure. You may. The group represented by A or B in the formula (4) is preferably a group having a total carbon number of 1 to 40, more preferably a group having a total carbon number of 1 to 40.
To 30 and may further have a substituent.
In formula (4), A and B more preferably combine with each other to form a cyclic structure. The cyclic structure formed at this time is preferably a 5- to 7-membered non-aromatic hetero ring, and preferably has a total carbon number of 1 to 40, and more preferably 3 to 30. In this case, an example in which A and B are linked (-AB
-) By way of, for example, _{-O- (CH 2) 2 -O -} , - O
_{- (CH 2) 3 -O -} , - S- (CH 2) 2 -S -, - S-
(CH ₂ ) ₃ -S-, -S-Ph-S-, -N (CH ₃ )-
_{(CH 2) 2 -O -,} - N (CH 3) - (CH 2) 2 -S
_{-, - O- (CH 2)} 2 -S -, - O- (CH 2) 3 -S
_{-, - N (CH 3)} -Ph-O -, - N (CH 3) -Ph-S
-, - N (Ph) - is (CH _{2) 2} -S- and the like.

The compounds represented by the formulas (2) to (4) used in the present invention may have incorporated therein an adsorptive group that adsorbs to silver halide. Examples of such adsorbing groups include alkylthio, arylthio, thiourea, thioamide, mercaptoheterocyclic, and triazole groups, which are described in U.S. Pat. Nos. 4,385,108 and 4,459,3.
No. 47, JP-A-59-195233 and JP-A-59-200.
No. 231, 59-201045, 59-2010
No. 46, No. 59-201047, No. 59-20104
No. 8, No. 59-201049, JP-A-61-1707.
No. 33, No. 61-270744, No. 62-948,
The groups described in JP-A-63-234244, JP-A-63-234245, and JP-A-63-234246 are exemplified. These adsorbing groups to silver halide may be precursors. Examples of such a precursor include the groups described in JP-A-2-285344. The compounds represented by the formulas (2) to (4) used in the present invention include:
A ballast group or a polymer commonly used in immobile photographic additives such as couplers may be incorporated therein. Particularly, those incorporating a ballast group are one of preferred examples of the present invention. 8 ballast groups
A group having the above number of carbon atoms, which is relatively inert to photographic properties.For example, select from an alkyl group, an aralkyl group, an alkoxy group, a phenyl group, an alkylphenyl group, a phenoxy group, and an alkylphenoxy group. Can be. As the polymer, for example, JP-A-1-1005
No. 30.

The compounds represented by the formulas (2) to (4) used in the present invention contain a cationic group (specifically,
A group containing a quaternary ammonium group or a nitrogen-containing heterocyclic group containing a quaternized nitrogen atom), a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, (alkyl, aryl, or heterocyclic) thio It may contain a group or a dissociable group which can be dissociated by a base (carboxy group, sulfo group, acylsulfamoyl group, carbamoylsulfamoyl group, etc.). In particular, a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, or (alkyl, aryl, or heterocycle)
Those containing a thio group are one of the preferred examples of the present invention.
One. Specific examples of these groups include, for example, JP-A-7-234471, JP-A-5-333466, JP-A-6-19032, JP-A-6-19031, JP-A-5-45761, U.S. Pat. The compounds described in U.S. Pat. No. 4,988,604, JP-A-3-259240, JP-A-7-5610, JP-A-7-244348, German Patent 4006032, and the like can be mentioned. Next, specific examples of the compounds represented by the formulas (2) to (4) used in the present invention are shown below. However, the present invention is not limited to the following compounds.

[0055]

Embedded image

[0056]

Embedded image

[0057]

Embedded image

The compounds represented by the formulas (2) to (4) used in the present invention may be water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone) , Methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. Also, by the well-known emulsification dispersion method,
An oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone can be used for dissolving and mechanically producing an emulsified dispersion for use. Alternatively, the powder of the compound represented by the formula (2) to the formula (4) is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or an ultrasonic wave by a method known as a solid dispersion method and used. Can be.

The compounds represented by the formulas (2) to (4) used in the present invention may be added to a layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on the layer side. It may be added, but is preferably added to the image forming layer or a layer adjacent thereto. The amount of the compounds represented by the formulas (2) to (4) is preferably 1 × 10 ^-6 to ¹ mol, more preferably 1 × 10 ^{-5 to} 5 × 10 ^-1 mol, per mol of silver. , 2 ×
Most preferably, it is 10 ^{-5 to} 2 × 10 ^-1 mol. Equation (2)-Equation
The compound represented by (4) can be easily synthesized by a known method. For example, US Pat. No. 5,545,51
5, US Pat. No. 5,635,339, US Pat.
No. 54,130, International Publication WO97 / 34196, or Japanese Patent Application Nos. 9-354107 and 9-3098.
No. 13, Japanese Patent Application No. 9-272002 can be synthesized with reference to the method described therein. Formula (2) used in the present invention
The compound represented by the formula (4) may be used alone or in combination of two or more. In addition to the above, US Pat. No. 5,545,515 and US Pat. No. 5,635,339
No. 5,654,130, International Publication WO97
/ 34196, the compounds described in U.S. Pat. No. 5,686,228;
Japanese Patent Application Nos. 9-309813 and 9-296174
No., Japanese Patent Application No. 9-282564, Japanese Patent Application No. 9-27200
No. 2, Japanese Patent Application No. 9-272003, Japanese Patent Application No. 9-3323
The compounds described in No. 88 may be used in combination.

Further, in the present invention, Japanese Patent Laid-Open No. 10-3
39932, Japanese Patent Application No. 9-240511,
The hydrazine derivatives described in JP-A-161270 can also be used in combination. Further, the following hydrazine derivatives can be used in combination. That is, the compounds represented by (Chemical Formula 1) described in JP-B-6-77138, specifically, the compounds described on pages 3 and 4 of the same publication. Compounds represented by the general formula (I) described in JP-B-6-93082, specifically, compounds 1 to 3 described in pages 8 to 18 of the same publication
Compound of 8. Compounds represented by formulas (4), (5) and (6) described in JP-A-6-230497, specifically, compound 4- described on pages 25 and 26 of the same publication. 1 to 4-10, compounds 5-1 to 5-42 described on pages 28 to 36, and compounds 6-1 to 6-7 described on pages 39 and 40. JP-A-6-289520
Compounds represented by the general formulas (1) and (2) described in the above publications, specifically, the compounds 1-1) to 1-17) and 2-1 described on pages 5 to 7 of the same publication. ). JP-A-6-31
Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in No. 3936, specifically, compounds described on pages 6 to 19 of the same publication. Compounds represented by (Chemical Formula 1) described in JP-A-6-313951, specifically, compounds described on pages 3 to 5 of the same. Compounds represented by formula (I) described in JP-A-7-5610, specifically, compounds I-1 to I-38 described on pages 5 to 10 of the same. Compounds represented by general formula (II) described in JP-A-7-77783, specifically, compounds II-1 to II-10 described on pages 10 to 27 of the same publication
2. Compounds represented by formulas (H) and (Ha) described in JP-A-7-104426, specifically, compounds H-1 to H-44 described on pages 8 to 15 of the same publication. A compound described in EP 713131A, which has an anionic group or a nonionic group that forms an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group. Particularly, a compound represented by the general formula (A): A compound represented by the formula (B), the general formula (C), the general formula (D), the general formula (E), or the general formula (F).
-1 to N-30. Compounds represented by the general formula (1) described in European Patent 713131A, and specifically, compounds D-1 to D-55 described in the publication. Further, various hydrazine derivatives described on pages 25 to 34 of "Known Techniques (pages 1 to 207)" (Aztec) published on March 22, 1991. JP 62
Compounds D-2 and D of -86354 (pages 6 to 7)
-39.

These hydrazine derivatives are dissolved in water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, methylcellosolve, etc. Can be used. Also, by an already well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone are dissolved and mechanically emulsified and dispersed. An object can be prepared and used. Alternatively, by a method known as a solid dispersion method, a powder of a hydrazine derivative is put into water using a ball mill, a colloid mill,
Alternatively, it can be dispersed and used by ultrasonic waves.

These hydrazine derivatives may be added to the layer on the image forming layer side with respect to the support, that is, to the image forming layer or any other layer on the layer side. It is preferred to add. The addition amount of these hydrazine derivatives is 1 × 10 ⁻⁶ to 1 mol of silver.
1 mol is preferable, 1 * 10 < ^-5 > to 5 * 10 <^-1> mol is more preferable, and 2 * 10 < ^-5 > to 2 * 10 <^-1> mol is most preferable. Further, acrylonitriles described in U.S. Pat. No. 5,545,515, specifically, CN-1 to CN-13 and the like can be used as a super-high contrast agent.

Further, the present invention provides a method for forming a super-high contrast image.
A high contrast accelerator can be used in combination with the above-mentioned super-high contrast agent. For example, the amine compounds described in U.S. Patent No. 5,545,505, specifically AM-1 to AM-5, and 5,545,507
, Specifically HA-1 to HA
Hydrazine compounds described in JP-A-5-558983, specifically CA-1 to CA-6, onium salts described in JP-A-9-297368, specifically A-1 to A-42, B-1 to B-
27, C-1 to C-14 and the like can be used. The synthesis method, addition method, addition amount, and the like of the above-mentioned super-high contrast agent and these high-contrast accelerators can be performed as described in each of the cited patents.

The heat-developable image-forming material of the present invention comprises a reducing agent,
In particular, it contains a reducing agent for an organic silver salt. A reducing agent for an organic silver salt is any substance that reduces silver ions to metallic silver,
Preferably, it may be an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred.
The reducing agent is used in an amount of 5 to 1 mol of silver on the surface having the image forming layer.
It is preferably contained at 50 mol%, more preferably at 10 to 40 mol%. The layer to which the reducing agent is added may be any layer on the side having the image forming layer. When it is added to a layer other than the image forming layer, it is preferable to use a relatively large amount of 10 to 50 mol% with respect to 1 mol of silver. Further, the reducing agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In a heat-developable image forming material using an organic silver salt, a wide range of reducing agents are disclosed in JP-A-46-6074 and JP-A-47-1238.
Nos. 47-33621, 49-46427, 49-115540, 5
0-14334, 50-36110, 50-147711, 51-32632
No. 51-1023721, No. 51-32324, No. 51-51933, No.
52-84727, 55-108654, 56-146133, 57-828
No. 28, 57-82829, JP-A-6-3793, U.S. Pat.
9586, 3,679,426, 3,751,252, 3,751,255
Nos. 3,761,270, 3,782,949, 3,839,048,
3,928,686, 5,464,738, German patent 2321328,
It is disclosed in European Patent No. 692732 and the like. For example, phenylamide oxime, 2-thienylamide oxime and
Amide oximes such as p-phenoxyphenylamide oxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehyde azine; combinations of 2,2′-bis (hydroxymethyl) propionyl-β-phenylhydrazine with ascorbic acid A combination of such an aliphatic carboxylic acid aryl hydrazide and ascorbic acid; a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (eg, hydroquinone and bis (ethoxyethyl) hydroxylamine, piperidinohexose reductone Or a combination of formyl-4-methylphenylhydrazine, etc.); phenylhydroxamic acid, p
Hydroxamic acids such as -hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; combinations of azines with sulfonamidophenols (eg, phenothiazine and 2,6-dichloro-4-benzenesulfonamidophenol); ethyl-α-cyano Α-cyanophenylacetic acid derivatives such as 2-methylphenylacetate and ethyl-α-cyanophenylacetate; 2,2′-dihydroxy-1,1′-binaphthyl, 6,6′-dibromo-2,2′-dihydroxy Bis-β-naphthol as exemplified by -1,1′-binaphthyl and bis (2-hydroxy-1-naphthyl) methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (eg, 2,4
-Dihydroxybenzophenone or 2 ', 4'-dihydroxyacetophenone); 3-methyl-1-phenyl
5-pyrazolone, such as -5-pyrazolone; reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone;
Sulfonamidophenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,3-
Dione and the like; chromanes such as 2,2-dimethyl-7-t-butyl-6-hydroxychroman; 1,4-dihydropyridines such as 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine; Bisphenols (e.g., bis (2-hydroxy-3
-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-
Bis (2-t-butyl-6-methylphenol), 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis (3,5 -Dimethyl-4-hydroxyphenyl) propane, etc.); ascorbic acid derivatives (for example,
And aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indan-1,3-diones; chromanol (such as tocopherol).

The reducing agent may be added by any method such as a solution, a powder, and a solid fine particle dispersion. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

In a preferred embodiment of the present invention, the heat-developable image-forming material of the present invention contains a photosensitive silver halide. Hereinafter, the photosensitive silver halide used in the present invention will be described in detail.

The photosensitive silver halide used in the present invention is not particularly limited in the halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. . The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously.
Further, silver halide grains having a core / shell structure can be preferably used. The structure is preferably 2
Core / shell particles having a ５5-fold structure, more preferably a 2- to 4-fold structure, can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

The method of forming the photosensitive silver halide used in the present invention is well known in the art, and includes, for example, those described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Can be used. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method of preparing a photosensitive silver halide grain by adding a silver supply compound and a halogen supply compound to another polymer solution and mixing the resultant with an organic silver salt can be used. In the present invention, the latter method can be preferably used. The particle size of the photosensitive silver halide is preferably small for the purpose of suppressing the white turbidity after image formation to be low.
20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less,
More preferably, the thickness is 0.02 μm or more and 0.12 μm or less. Here, the grain size means the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical grains, rod-shaped grains, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grain is not particularly limited, but the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high.
The proportion occupied by the [100] plane is preferably high. The ratio is preferably 50% or more, more preferably 65% or more,
80% or more is more preferable. The Miller index [100] plane ratio was determined by T. Tani; J. Imaging Sci., 29, 165 (1985), which utilizes the adsorption dependence of [111] and [100] planes on the adsorption of sensitizing dyes. It can be determined by the method described.

The photosensitive silver halide grains for use in the present invention are preferably selected from the group VII or VIII (groups 7 to 7) of the periodic table.
It preferably contains a metal of Group 10) or a metal complex. Rhodium, rhenium, ruthenium, osmium and iridium are preferred as the metal of Group VII or VIII of the periodic table or the central metal of the metal complex. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 10 ^-9 mol to 10 ^-2 mol, preferably 10 ^-8 mol to 10 ^-4 mol, per mol of silver. As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used.

As the rhodium compound preferably used in the present invention, a water-soluble rhodium compound can be used. For example, a rhodium (III) halide compound or a rhodium complex salt having a ligand such as halogen, amines, oxalato, etc., for example, hexachlororhodium (III) complex salt, pentachloroacolodium (III) complex salt,
Tetrachlorodiachodium (III) complex salt, hexabromorhodium (III) complex salt, hexaamminerhodium (II)
I) complex salts and trizalatrodium (III) complex salts. These rhodium compounds are used by dissolving them in water or a suitable solvent. A method generally used for stabilizing a solution of the rhodium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, bromic acid, fluoride, etc.) Hydrogen acid, etc.) or alkali halides (eg KCl, NaC
l, KBr, NaBr, etc.) can be used. Instead of using water-soluble rhodium, it is also possible to add and dissolve other silver halide grains doped with rhodium during the preparation of silver halide.

The amount of these rhodium compounds added is
1 × 10 per mole of silver halide^-8Mol to 5 × 10^-6Mole of
The range is preferably, particularly preferably 5 × 10^-8Mol ~ 1x
10 ^-6Is a mole. The addition of these compounds is
Steps during the production of silver halide emulsion grains and before coating the emulsion
Can be suitably performed, but in particular,
And preferably incorporated into silver halide grains.
No.

Rhenium, ruthenium and osmium preferably used in the present invention are described in JP-A-63-2042 and JP-A-1-2859.
It is added in the form of a water-soluble complex salt described in JP-A Nos. 41, 2-20852, 2-20855 and the like. Particularly preferred is a six-coordinate complex represented by the following formula. [ML ₆ ] ⁿ -where M represents Ru, Re, or Os, L represents a ligand, and n represents 0, 1, 2, 3, or 4. In this case, the counter ion is not important and ammonium or alkali metal ions are used.

Preferred ligands include halide ligands, cyanide ligands, cyanide ligands, nitrosyl ligands, thionitrosyl ligands and the like.
Examples of specific complexes used in the present invention are shown below, but the present invention is not limited thereto.

[ReCl ₆ ] ^3- [ReBr ₆ ] ^3- [ReCl ₅ (NO)] ^2- [Re (NS) Br ₅ ] ^2- [Re (NO) (CN) ₅ ] ^2- [Re (O ) ₂ (CN) ₄ ] ^3- [RuCl ₆ ] ^3- [RuCl ₄ (H ₂ O) ₂ ] ^- [RuCl ₅ (H ₂ O)] ^2- [RuCl ₅ (NO)] ^2- [RuBr ₅ ( NS)] ^2- [Ru (CO) ₃ Cl ₃ ] ^2- [Ru (CO) Cl ₅ ] ^2- [Ru (CO) Br ₅ ] ^2- [OsCl ₆ ] ^3- [OsCl ₅ (NO)] ^{2 -} [Os (NO) (CN) ₅ ] ^2- [Os (NS) Br ₅ ] ^2- [Os (O) ₂ (CN) ₄ ] ^4-

The addition amount of these compounds is 1
It is preferably in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻⁵ mol per mol, particularly preferably 1 × 10 ⁻⁸ mol to 1 × 10 ⁻⁶ mol. These compounds can be appropriately added at the time of the production of silver halide emulsion grains and at each stage before coating the emulsion, but it is particularly preferable to add them at the time of emulsion formation and incorporate them into the silver halide grains. . In order to add these compounds during silver halide grain formation and incorporate them into silver halide grains, a metal complex powder or an aqueous solution dissolved together with NaCl or KCl is added to a water-soluble salt or a water-soluble salt during grain formation. A method in which silver halide grains are added to a neutral halide solution, or a third solution is added when a silver salt and a halide solution are simultaneously mixed, and silver halide grains are prepared by a three-solution simultaneous mixing method, or a grain formation method. There is a method in which a required amount of an aqueous solution of a metal complex is charged into a reaction vessel. In particular, a method of adding a powder or an aqueous solution dissolved together with NaCl and KCl to a water-soluble halide solution is preferable.

For the addition to the particle surface, a required amount of an aqueous solution of a metal complex can be charged into the reaction vessel immediately after the formation of the particles, during or during physical ripening, or at the time of chemical ripening. Various compounds can be used as the iridium compound preferably used in the present invention, and examples thereof include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used after being dissolved in water or a suitable solvent. However, a method generally used for stabilizing a solution of the iridium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) is used. Etc.) or a method of adding an alkali halide (eg, KCl, NaCl, KBr, NaBr, etc.). Instead of using water-soluble iridium, it is also possible to add and dissolve another iridium-doped silver halide grain during silver halide preparation.

The silver halide grains used in the present invention may further include cobalt, iron, nickel, chromium, palladium,
It may contain metal atoms such as platinum, gold, thallium, copper and lead. For compounds of cobalt, iron, chromium, and ruthenium, hexacyano metal complexes can be preferably used. Specific examples include ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion,
Examples include, but are not limited to, hexacyanochromate ions, hexacyanoruthenate ions, and the like. The metal complex in the silver halide may be contained uniformly, may be contained in the core portion at a high concentration, or may be contained in the shell portion at a high concentration, and there is no particular limitation. The metal is 1 × 10 ^-9 to 1 × 1 per mol of silver halide.
^0-4 moles are preferred. Further, in order to contain the above-mentioned metal, a metal salt in the form of a single salt, a double salt or a complex salt can be added at the time of preparing particles.

The photosensitive silver halide grains can be desalted by washing with water by a method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted. . The silver halide emulsion used in the present invention is preferably chemically sensitized. As the method of chemical sensitization, known methods such as a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, and a noble metal sensitization method can be used, and these are used alone or in combination. When used in combination, for example, sulfur sensitization and gold sensitization, sulfur sensitization and selenium sensitization and gold sensitization, sulfur sensitization and tellurium sensitization and gold sensitization, Sulfur sensitization, selenium sensitization, tellurium sensitization, gold sensitization and the like are preferred.

The sulfur sensitization used in the present invention is usually carried out by
Add a yellow sensitizer and keep the emulsion at a high temperature of 40 ° C or more.
It is performed by stirring for a while. Public sulfur sensitizer
Known compounds can be used, for example, in gelatin
In addition to the sulfur compounds contained in, various sulfur compounds, such as
Thiosulfate, thioureas, thiazoles, rhodanine
Can be used. Preferred sulfur compounds are
Osulfates and thiourea compounds. Amount of sulfur sensitizer added
Indicates the pH, temperature, and size of silver halide grains during chemical ripening
Changes under various conditions, such as silver halide.
10 per mole ^-7-10^-2Mole, more preferably
10^-Five-10^-3Is a mole.

As the selenium sensitizer used in the present invention, known selenium compounds can be used. That is, it is usually carried out by adding an unstable and / or non-unstable selenium compound and stirring the emulsion at a high temperature of 40 ° C. or higher for a certain time. As unstable selenium compounds, JP-B-44-15748, JP-B-43-13489, JP-A-4-25832,
The compounds described in JP-A Nos. 4-109240 and 4-324855 can be used. In particular, it is preferable to use the compounds represented by formulas (VIII) and (IX) in JP-A-4-324855.

The tellurium sensitizer used in the present invention is a compound that forms silver telluride which is presumed to be a sensitizing nucleus on the surface or inside of silver halide grains. The formation rate of silver telluride in a silver halide emulsion is described in JP-A-5-3132.
It can be tested by the method described in No. 84. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals,
Tellurosulfonates, compounds having a P-Te bond, containing T
e Heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Specifically, U.S. Patent Nos. 1,623,499, 3,320,069, 3,772,031, UK Patent 235,211 and 1,121,496,
No. 1,295,462, No. 1,396,696, Canadian Patent 800,9
No. 58, JP-A-4-204640, JP-A-4-273341, JP-A-4-330343, JP-A-5-303157, Journal of Chemical Society Chemical Communication (J. Chem. Soc. Chem. Commun. .) 635 (1980),
ibid 1102 (1979), ibid 645 (1979), Journal of Chemical Society Parkin Transaction (J. Chem. Soc. Perkin. Trans.) 1, 2191 (1980), S. Patai Ed., The Chemistry of Organic Serenium and Tellunium
Compounds), Vol. 1 (1986) and the compounds described in Vol. 2 (1987) can be used. In particular, compounds represented by formulas (II), (III) and (IV) in JP-A-5-313284 are preferred.

[0084] The amount of the selenium and tellurium sensitizers used in the present invention, the silver halide grains to be used, but the chemical ripening condition and the like and, generally, per mol of silver halide 10 ^-8 to 10 ^-2 mol, Preferably, about 10 ^-7 to 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, preferably 7 to 10, and the temperature is 40 to 95 ° C, preferably 45 to 45 ° C. 85 ° C. Examples of the noble metal sensitizer used in the present invention include gold, platinum, palladium, and iridium, and gold sensitization is particularly preferable. Specific examples of the gold sensitizer used in the present invention include chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, and gold sulfide, and 10 ^-7 to 10 ^-2 mol per mol of silver halide. Degrees can be used.

In the silver halide emulsion used in the present invention, a cadmium salt, a sulfite, a lead salt, a thallium salt, and the like may be coexistent during the formation of silver halide grains or physical ripening. In the present invention, reduction sensitization can be used. Specific compounds of the reduction sensitization method include, as well as ascorbic acid, thiourea dioxide, for example, stannous chloride,
Aminoiminomethanesulfinic acid, hydrazine derivatives,
Borane compounds, silane compounds, polyamine compounds and the like can be used. Also, adjust the pH of the emulsion to 7 or more or pAg.
Reduction sensitization can be achieved by ripening while keeping the temperature at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation. To the silver halide emulsion used in the present invention, a thiosulfonic acid compound may be added by the method described in EP 293,917.

The silver halide emulsion in the image forming material used in the present invention may be only one kind or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, those having different crystal habits, Those having different conditions of chemical sensitization) may be used together. The amount of the photosensitive silver halide to be used is preferably 0.01 mol or more and 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less, particularly preferably 0.03 mol or more and 0.25 mol or less, based on 1 mol of the organic silver salt. preferable. Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and the organic silver salt were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer, etc. And the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt, and the like,
There is no particular limitation as long as the effects of the present invention are sufficiently exhibited.

The organic silver salt which can be used as the reducible silver salt in the heat-developable image-forming material of the present invention is relatively stable to light, but is exposed to an exposed photocatalyst (a latent silver halide). Image) and in the presence of a reducing agent, 80
It is a silver salt that forms a silver image when heated to a temperature of ℃ or more. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Silver salts of organic acids, especially
Silver salts of long chain fatty carboxylic acids (with 10-30, preferably 15-28 carbon atoms) are preferred. Also preferred are complexes of organic or inorganic silver salts wherein the ligand has a complex stability constant in the range of 4.0 to 10.0. The silver donor material can preferably make up about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate,
Silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and silver camphorate, And mixtures thereof.

A silver salt of a compound containing a mercapto group or a thione group and derivatives thereof can also be used.
Preferred examples of these compounds include 3-mercapto-4
-Phenyl-1,2,4-triazole silver salt, 2-mercaptobenzimidazole silver salt, 2-mercapto-5-aminothiadiazole silver salt, 2- (ethylglycolamide) benzothiazole silver salt, S- Silver salts of thioglycolic acid such as silver salts of alkylthioglycolic acid (where the alkyl group has 12 to 22 carbon atoms), silver salts of dithiocarboxylic acids such as silver salts of dithioacetic acid, silver salts of thioamides, 5 -Carboxyl-1-methyl-2-phenyl-4-thiopyridine silver salt, mercaptotriazine silver salt, 2-mercaptobenzoxazole silver salt, silver salts described in U.S. Pat.No.4,123,274, for example, 3-amino-5 Silver salts of 1,2,4-mercaptothiazole derivatives such as -benzylthio-1,2,4-thiazole silver salt, 3- (3-carboxyethyl) -4- described in U.S. Pat.No. 3,301,678
Includes silver salts of thione compounds such as silver salt of methyl-4-thiazoline-2-thione. Furthermore, compounds containing an imino group can also be used. Preferred examples of these compounds include silver salts of benzotriazole and derivatives thereof,
For example, silver salts of benzotriazole such as silver methylbenzotriazole, silver salts of halogen-substituted benzotriazole such as silver 5-chlorobenzotriazole, U.S. Pat.
0,709 1,2,4-triazole or 1-H-
Includes silver salts of tetrazole, silver salts of imidazole and imidazole derivatives, and the like. For example, U.S. Pat.
Various silver acetylide compounds as described in No. 1 and 4,775,613 can also be used.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but a needle crystal having a short axis and a long axis is preferable. In the present invention, the minor axis is 0.01 μm or more and 0.2 μm or more.
0 μm or less, major axis of 0.10 μm or more and 5.0 μm or less, minor axis of 0.01 μm or more and 0.15 μm or less, and major axis of 0.10 μm or more and 4.0 μm or less are more preferred. The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the percentage of the value obtained by dividing the standard deviation of the length of each major axis by each minor axis, major axis is preferably 100% or less, more preferably 80% or less,
More preferably, it is 50% or less. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. As another method of measuring the monodispersity, there is a method of determining the standard deviation of the volume-weighted average diameter of the organic silver salt, the percentage of the value divided by the volume-weighted average diameter (coefficient of variation) is preferably 100% or less, more Preferably 80% or less,
More preferably, it is 50% or less. As a measuring method, for example, the particle size (volume weighted average diameter) obtained by irradiating a laser beam to an organic silver salt dispersed in a liquid and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. Can be.

The organic silver salt that can be used in the present invention includes:
Preferably, desalting can be performed. The method for desalting is not particularly limited, and a known method can be used. However, a known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, or floc-forming water washing by a coagulation method can be preferably used. In the present invention, for the purpose of obtaining an organic silver salt solid dispersion having a high S / N, a small particle size, and no aggregation, the organic silver salt containing an image forming medium is contained, and the photosensitive silver salt is substantially contained. It is preferable to use a dispersion method in which an aqueous dispersion is converted into a high-speed stream and then the pressure is reduced. After passing through such a process, the mixture is mixed with a photosensitive silver salt aqueous solution to produce a photosensitive image forming medium coating solution. When a heat-developable image forming material is prepared using such a coating liquid, haze is low,
A low-fogging and high-sensitivity heat-developable image forming material can be obtained. On the other hand, when the photosensitive silver salt is coexistent when the light is converted into a high-pressure and high-speed flow and dispersed, the fog increases and the sensitivity is liable to decrease remarkably. When an organic solvent is used instead of water as a dispersion medium, haze increases, fog increases, and sensitivity tends to decrease. On the other hand, when a conversion method for converting a part of the organic silver salt in the dispersion liquid to the photosensitive silver salt is used instead of the method of mixing the aqueous solution of the photosensitive silver salt, the sensitivity tends to be lowered. In the above, the high pressure, the aqueous dispersion is dispersed and converted to high speed, is substantially free of photosensitive silver salt, the content is 0.1 mol% based on the non-photosensitive organic silver salt In the following, the photosensitive silver salt was not positively added.

In the present invention, the solid dispersion apparatus and the technique used for carrying out the dispersion method as described above are described in, for example, “Dispersion Rheology and Dispersion Technique” (Toshio Kajiuchi and Hiroki Usui, 1991, Shinzansha Publishing Co., Ltd., p357
-P403), "The 24th Progress of Chemical Engineering", edited by The Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p184-p185),
Although detailed in the dispersing method of the present invention, the aqueous dispersion containing at least an organic silver salt is pressurized by a high-pressure pump or the like and sent into a pipe, and then passed through a narrow slit provided in the pipe, Thereafter, the dispersion is finely dispersed by causing an abrupt pressure drop in the dispersion. As for the high-pressure homogenizer to which the present invention is related, generally, (a) the dispersoid is released at a normal pressure from a high pressure under a high pressure, and `` shearing force '' generated when the dispersoid passes through a narrow gap at a high speed. It is considered that the particles are dispersed into fine particles by a dispersing force such as “cavitation force” generated when the particles are dispersed. As an example of this type of dispersing apparatus, a Gaulin homogenizer is mentioned in the past.In this apparatus, the liquid to be dispersed sent at a high pressure is converted into a high-speed flow through a narrow gap on a cylindrical surface, and the force is applied to the surrounding wall by the force. The particles collide and are emulsified and dispersed by the impact force. Operating pressure is generally 100~600kg / cm ^2, the number is the flow velocity m~3
It is in the range of 0 m / sec, and in order to increase the dispersion efficiency, a device in which the high flow rate portion is saw-toothed and the number of collisions is increased has been devised. On the other hand, in recent years, apparatuses capable of dispersing at higher pressure and higher flow rate have been developed, and typical examples thereof include a microfluidizer (Microfluidex International Corporation) and a nanomizer (specialized machine). Industrial Co., Ltd.).

As a dispersing apparatus suitable for the present invention, a microfluidizer M-110S-EH manufactured by Microfluidics International Corporation is used.
(With G10Z interaction chamber), M-
110Y (with H10Z interaction chamber), M-140K (with G10Z interaction chamber), HC-5000 (L30Z or H23
With 0Z interaction chamber), HC-80
00 (with an E230Z or L30Z interaction chamber) and the like. Using these devices,
After the aqueous dispersion containing at least the organic silver salt is pressurized by a high-pressure pump or the like and sent into the pipe, a desired pressure is applied by passing through a narrow slit provided in the pipe, and thereafter, the inside of the pipe is It is possible to obtain an optimal organic silver salt dispersion for the present invention by causing a rapid pressure drop in the dispersion by, for example, rapidly returning the pressure to the atmospheric pressure.

In the dispersion of an organic silver salt, it is possible to disperse a desired particle size by adjusting the flow rate, the differential pressure at the time of pressure drop, and the number of treatments. / Sec to 600m / sec, the differential pressure during pressure drop
Is preferably in the range of 900~3000kg / cm ^2, the flow rate is 300 meters / sec to 60
More preferably, the pressure difference at the time of 0 m / sec and the pressure drop is in the range of 1500 to 3000 kg / cm ² . The number of times of distributed processing can be selected as needed, and usually 1 to 10 times of processing is selected,
From the viewpoint of productivity, the number of treatments is selected from about 1 to 3 times.
High temperature of such an aqueous dispersion under high pressure is not preferable from the viewpoint of dispersibility and photographic properties, and at a high temperature such as exceeding 90 ° C., the particle size tends to increase,
Fog tends to be high. Therefore, in the present invention, the step before the conversion to the high pressure and high flow rate, the step after the pressure is reduced, or both of these steps include a cooling step, and the temperature of such water dispersion is reduced by the cooling step. ~ 90
C. It is preferably maintained in the range of 5 ° C., more preferably in the range of 5 to 80 ° C., particularly preferably in the range of 5 to 65 ° C. In particular, it is effective to provide the above cooling step at the time of high-pressure dispersion in the range of 1500 to 3000 kg / cm ² .
As the cooler, a double tube, a double tube using a static mixer, a multi-tube heat exchanger, a coiled tube heat exchanger, or the like can be appropriately selected according to the required heat exchange amount. Further, in order to increase the efficiency of heat exchange, it is sufficient to select a suitable one such as a pipe thickness, a wall thickness and a material in consideration of a working pressure. As the refrigerant used for the cooler, use 20 ° C well water, 5-10 ° C cold water treated with a refrigerator, and, if necessary, -30 ° C ethylene glycol / water refrigerant, etc., based on the heat exchange amount. You can also.

In the dispersion operation, it is preferable to disperse the organic silver salt in the presence of an aqueous solvent-soluble dispersant (dispersion aid). Examples of the dispersing agent include polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, a synthetic anionic polymer such as an acrylomethylpropanesulfonic acid copolymer, and carboxymethyl. Starch, semi-synthetic anionic polymer such as carboxymethyl cellulose, alginic acid, anionic polymer such as pectic acid, the compound described in JP-A-7-350753,
Alternatively, known anionic, nonionic, cationic surfactants and other known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or naturally occurring polymer compounds such as gelatin Can be appropriately selected and used, but polyvinyl alcohols and water-soluble cellulose derivatives are particularly preferred.

It is a general method that the dispersing agent is mixed with the organic silver salt powder or the organic silver salt in a wet cake state before the dispersion and then sent as a slurry to the dispersing machine. Heat treatment or treatment with a solvent may be performed in the combined state to obtain an organic silver salt powder or a wet cake. The pH may be controlled by a suitable pH adjuster before, during or after dispersion. In addition to mechanical dispersion, pH
By performing control, the particles may be roughly dispersed in a solvent, and then the pH may be changed in the presence of a dispersing agent to form fine particles. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation. The prepared dispersion is stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or stored in a highly viscous state by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also. Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage. The organic silver salt can be used in any desired amount,
Indicates the coating amount per image forming material 1 m ^2, as silver
Preferably 0.1-5 g / m ^2, more preferably from 1 to 3 g / m ^2.

When an additive known as a "toning agent" for improving an image is included, the optical density may be increased. Toning agents may also be advantageous in forming black silver images. The toning agent is preferably contained in an amount of 0.1 to 50% (mole) per mole of silver on the surface having the image forming layer, and more preferably 0.5 to 20% (mole).
Further, the toning agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In a heat-developable image forming material using an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077 and JP-A-47-1028.
No. 2, No. 49-5019, No. 49-5020, No. 49-91215, No. 49-
No. 91215, No. 50-2524, No. 50-32927, No. 50-67132,
No. 50-67641, No. 50-114217, No. 51-3223, No. 51-279
No. 23, No. 52-14788, No. 52-99813, No. 53-1020, No. 5
3-76020, 54-156524, 54-156525, 61-1836
No. 42, JP-A-4-56848, JP-B-49-10727, 54-2033
No. 3, U.S. Pat.Nos. 3,080,254, 3,446,648, 3,782,9
No. 41, No. 4,123,282, No. 4,510,236, British Patent 138079
No. 5, Belgian Patent No. 841910 and the like. Examples of toning agents are phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one, and quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione Cyclic imides such as; naphthalimides (eg, N
-Hydroxy-1,8-naphthalimide); cobalt complexes (eg, cobalt hexamine trifluoroacetate); 3-
Mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole Illustrative mercaptans; N- (aminomethyl) aryldicarboximides, such as (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl)-
Naphthalene-2,3-dicarboximide); and blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (eg, N, N′-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1 , 8- (3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2-tribromomethylsulfonyl- (benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothiazolyl) Nylidene) -1-methylethylidene] -2-thio-2,4-oxazolidinedione; phthalazinone, phthalazinone derivative or metal salt, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxy Derivatives such as phthalazinone and 2,3-dihydro-1,4-phthalazinedione; phthalazinone and phthalic acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachloro- Combination of anhydride such as phthalic acid); phthalazine, phthalazine derivatives (e.g., 4- (1-naphthyl) phthalazine, 6
-Chlorophthalazine, 5,7-dimethoxyphthalazine, 6-iso
Derivatives such as -butylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine, and 2,3-dihydrophthalazine) or metal salts; phthalazine and its derivatives and phthalic acid derivatives (for example, phthalic acid Quinazolinedione, benzoxazine or naphthoxazine derivatives; halides for silver halide formation in situ as well as color tone regulators Rhodium complexes that also function as sources of ions, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and persulfates, such as
Ammonium disulfide and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine Benzoxazine-2,4-dione such as -2,4-dione; pyrimidine and asymmetric triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil, and tetraazapentane Ren derivatives (e.g., 3,6-dimercapto-1,4-diphenyl-1H, 4H-
2,3a, 5,6a-tetraazapentalene and 1,4-di (o-chlorophenyl) -3,6-dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene) is there.

In the present invention, the color-toning agent may be a solution, a powder,
It may be added by any method such as a solid fine particle dispersion.
The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

As the binder for the image forming layer (photosensitive layer, emulsion layer) in the heat-developable image forming material of the present invention, well-known natural or synthetic resins, for example, gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate , Cellulose acetate, polyolefin, polyester, polystyrene, polyacrylonitrile, polycarbonate and the like. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymer, maleic anhydride copolymer, polystyrene and butadiene-styrene copolymer. If necessary, two or more of these polymers can be used in combination. Such polymers are:
It is used in an amount sufficient to retain the ingredients therein. That is, it is used in a range effective to function as a binder. The effective range can be appropriately determined by those skilled in the art. As a guide when at least the organic silver salt is retained, the ratio of the binder to the organic silver salt is 15: 1 to 1:
2, especially the range of 8: 1 to 1: 1 is preferred.

At least one of the image forming layers of the heat-developable image forming material of the present invention is preferably an image forming layer containing the polymer latex described below in an amount of 50% by weight or more of the total binder. (Hereinafter, this image forming layer is referred to as “image forming layer in the present invention” and the polymer latex used for the binder is referred to as “polymer latex used in the present invention.” When the heat-developable image-forming material of the present invention is used for printing in which dimensional change is a problem, it is necessary to use a polymer latex for the protective layer and the back layer. However, the "polymer latex" referred to here is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As a dispersion state, a polymer is emulsified in a dispersion medium,
Emulsion polymerization, micellar dispersion, or a polymer having a partially hydrophilic structure in a polymer molecule and molecular chains themselves molecularly dispersed may be used. As for the polymer latex used in the present invention, `` Synthetic resin emulsion (Taira Okuda, edited by Hiroshi Inagaki, published by Polymer Publishing Association (19
78))), `` Application of synthetic latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, published by Polymer Publishing Association (199)
3)) "and" Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970)) "and the like. The average particle size of the dispersed particles is preferably in the range of 1 to 50,000 nm, more preferably about 5 to 1000 nm. There is no particular limitation on the particle size distribution of the dispersed particles, and those having a wide particle size distribution or those having a monodispersed particle size distribution may be used.

The polymer latex used in the present invention may be a so-called core / shell type latex other than a polymer latex having a normal uniform structure. In this case, it may be preferable to change the glass transition temperature of the core and the shell. The preferred range of the glass transition temperature (Tg) of the polymer of the polymer latex used as a binder in the present invention differs between the protective layer, the back layer and the image forming layer. In the image forming layer, the temperature is preferably 40 ° C. or lower, more preferably -30 to 40 ° C., in order to promote diffusion of the photographically useful material during thermal development. When used for the protective layer or the back layer, a glass transition temperature of 25 to 70 ° C. is preferable for contacting various devices. Minimum film forming temperature of polymer latex used in the present invention
(MFT) is preferably -30 ° C to 90 ° C, more preferably about 0 ° C to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. The film-forming aid is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of the polymer latex, also called a plasticizer, and is described in, for example, `` Synthesis of Synthetic Latex (Souichi Muroi, published by Polymer Publishing Association (1970) )"It is described in.

The polymer species used for the polymer latex used in the present invention include acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber resin, vinyl chloride resin, vinylidene chloride resin, polyolefin resin, or a copolymer thereof. and so on. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is preferably from 5000 to 100000, more preferably from about 10,000 to 100,000 in number average molecular weight. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

Specific examples of the polymer latex used as a binder for the image forming layer of the heat-developable image forming material of the present invention include the following. Latex of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer, latex of styrene / butadiene / acrylic acid copolymer, latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer Latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like. Such polymers are also commercially available,
The following polymers can be used. For example, as an example of an acrylic resin, Sebian A-4635,46583,4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 82
Polyester resins such as 0, 857 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 611, 675, 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-size, WMS (all manufactured by Eastman Chemical Co., Ltd.) HYDRAN for polyurethane resin
LACSTAR 7310K, 3307B, 4700 are rubber-based resins such as AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.)
H, 7132C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol Lx41
6, 410, 438C, 2507 (Nippon Zeon Co., Ltd.), etc .; vinyl chloride resins such as G351 and G576 (Nippon Zeon Co., Ltd.); vinylidene chloride resins L502, L51
3 (All made by Asahi Kasei Corporation), Aron D7020, D504, D507
Examples of olefin resins include Chemipearl S120 and SA100 (both manufactured by Mitsui Petrochemical Co., Ltd.). These polymers may be used alone or as a blend of two or more as necessary.

In the image forming layer according to the invention, the polymer latex is preferably used in an amount of 50% by weight or more of the total binder, and more preferably 70% by weight or more. In the image forming layer in the present invention, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, or hydroxypropyl methyl cellulose may be added as needed in the range of 50% by weight or less of the whole binder. . The amount of these hydrophilic polymers added is 30% of the total binder of the image forming layer.
% By weight or less, more preferably 15% by weight or less.

The image forming layer in the present invention is preferably prepared by applying an aqueous coating solution and then drying it. However, the `` water-based '' here is 60% by weight of the solvent (dispersion medium) of the coating liquid.
It means that the above is water. As components other than water of the coating solution, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following in addition to water. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 9
0/10, water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 80/15/5, water / methanol / dimethylformamide = 90/5/5. (However, the numbers represent% by weight.) The total binder amount of the image forming layer in the present invention is 0.2 to 30 g.
/ M ² , more preferably in the range of 1 to 15 g / m ² . A crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the image forming layer in the invention.

As the sensitizing dye used in the present invention, any sensitizing dye can be used as long as it can spectrally sensitize the silver halide grains in a desired wavelength region when adsorbed on the silver halide grains. As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, and the like can be used. Useful sensitizing dyes for use in the present invention include, for example, RESEARCH DISCLOSURE Item 17
Item 643IV-A (p.23, December 1978), Item 1831X (August 1979)
p.437) or in the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light source of various laser imagers, scanners, imagesetters and plate making cameras can be advantageously selected. Examples of spectral sensitization to red light include, for so-called red light sources such as He-Ne lasers, red semiconductor lasers, and LEDs, I-1 to I-38 described in JP-A-54-18726.
The compound of I-1 to I-35 described in JP-A-6-75322 and the compound of I-1 to I-34 described in JP-A-7-287338, described in JP-B-55-39818 Dyes 1 to 20, compounds of I-1 to I-37 described in JP-A-62-284343 and compounds of I-1 to I-34 described in JP-A-7-287338 are advantageously selected. .

For a semiconductor laser light source in the wavelength region of 750 to 1400 nm, cyanine, merocyanine, styryl,
A variety of known dyes, including hemicyanine, oxonol, hemioxonol and xanthene dyes, can be spectrally sensitized favorably. Useful cyanine dyes are, for example, cyanine dyes having a basic nucleus, such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and an imidazole nucleus. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
3,719,495, 3,877,943, British Patent 1,466,201,
No. 1,469,117, No. 1,422,057, No. 3-10391, No. 6
-52387, JP-A-5-341432, JP-A-6-94781, JP-A-6-3011
The dye may be appropriately selected from known dyes as described in No. 41.

Particularly preferred as the structure of the dye used in the present invention is a cyanine dye having a thioether bond-containing substituent (for example, JP-A-62-58239 and JP-A-3-13863).
No.8, No.3-138642, No.4-255840, No.5-72659, No.5-
No. 72661, No. 6-222491, No. 2-230506, No. 6-258757
No., 6-317868, 6-324425, Tokuyohei 7-500926,
Dyes described in U.S. Pat.No. 5,541,054), dyes having a carboxylic acid group (for example, JP-A-3-163440, JP-A-6-30114)
No. 1, U.S. Pat.No. 5,441,899), merocyanine dyes, polynuclear merocyanine dyes and polynuclear cyanine dyes
(JP 47-6329, JP 49-105524, JP 51-127719, JP
52-80829, 54-61517, 59-214846, 60-6750
No. 63-159841, JP-A-6-35109, JP-A-6-59381,
And the dyes described in JP-A-7-146537, JP-A-7-146537, JP-T-55-50111, British Patent 1,467,638, and US Patent 5,281,515. Further, as a dye forming a J-band, U.S. Pat.No. 5,510,236, the dye described in Example 5 of 3,871,887, JP-A-2-96131, JP-A-59-48753 are disclosed, and are preferably used in the present invention. Can be used.

These sensitizing dyes may be used alone.
Two or more kinds may be used in combination. Combinations of sensitizing dyes are often used, especially for supersensitization. In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are
Research Disclosure Volume 176, 17643 (Issued December 1978) No. 23
Section IV on page IV, or JP-B-49-25500, 43-43933,
These are described in JP-A-59-19032 and JP-A-59-192242. In order to add a sensitizing dye to a silver halide emulsion,
They may be dispersed directly in the emulsion, or
Methanol, ethanol, propanol, acetone, methylcellosolve, 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-
A solvent such as propanol and N, N-dimethylformamide alone or in a mixed solvent may be added to the emulsion.
Further, as disclosed in U.S. Pat.No. 3,469,987, a dye is dissolved in a volatile organic solvent, this solution is dispersed in water or a hydrophilic colloid, and this dispersion is added to the emulsion. Method, JP-B-44-23389, 44-27555,
As disclosed in JP-A-57-22091 and the like, a method of dissolving a dye in an acid and adding this solution to an emulsion, or adding an acid or a base to an emulsion as an aqueous solution in the presence of an acid or base, U.S. Pat. No. 4,006,025, a method of adding an aqueous solution or a colloidal dispersion in the presence of a surfactant to an emulsion as disclosed in
-102733, a method of directly dispersing a dye in a hydrophilic colloid as disclosed in JP-A-58-105141, and adding the dispersion to an emulsion, disclosed in JP-A-51-74624. As described above, a method in which a dye is dissolved using a compound that causes a red shift, and this solution is added to an emulsion can also be used. Also, ultrasonic waves can be used for dissolution.

The sensitizing dye used in the present invention may be added to the silver halide emulsion at any time during the preparation of the emulsion which has been recognized to be useful.
For example, U.S. Pat.Nos. 2,735,766, 3,628,960, 4,183,
No. 756, 4,225,666, JP-A-58-184142, 60-1967
As disclosed in the specification of No. 49, etc., the stage before silver halide grain formation step and / or before desalting, during the desalting step and / or after desalting and before the start of chemical ripening, As disclosed in the specification of Japanese Patent Application Laid-Open No. 58-113920, etc., any time, step, immediately before or during chemical ripening, any time after chemical ripening and before coating, before the emulsion is coated. May be added. Also, as disclosed in the specification of U.S. Pat. No. 4,225,666, JP-A-58-7629, etc., the same compound may be used alone or in combination with a compound having a different structure, for example, during the particle forming step. The compound may be added separately during the ripening step or after the completion of the chemical ripening, or may be added separately before or during the chemical ripening or after the completion of the chemical ripening. May be added. The amount of the sensitizing dye used may be a desired amount in accordance with the performance such as sensitivity and fog, but is preferably 10 ^-6 to 1 mol, more preferably 10 ^-4 to 10 ^-1 per mol of silver halide in the photosensitive layer. Mole is more preferred.

The heat-developable image-forming material of the present invention may contain a mercapto compound, a disulfide, or the like for controlling development by suppressing or accelerating development, improving spectral sensitization efficiency, or improving storage stability before and after development. Compounds and thione compounds can be contained. When a mercapto compound is used in the present invention, it may have any structure, but is preferably a compound represented by Ar- ^SMo or Ar-SS-Ar. Wherein, M ^o is a hydrogen atom or an alkali metal atom, Ar is an aromatic ring or fused aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atom. Preferably, the heteroaromatic rings in these groups are benzimidazole, naphthimidazole, benzothiazole,
Naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. This heteroaromatic ring is
For example, halogens (e.g., Br and Cl), hydroxy,
Amino, carboxy, alkyl (e.g., having one or more carbon atoms, preferably having 1-4 carbon atoms), alkoxy (e.g., one or more carbon atoms, preferably
It may have a substituent selected from the group consisting of those having 4 carbon atoms) and aryl (which may have a substituent). As mercapto-substituted heteroaromatic compounds, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2,2 '-Dithiobis-benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-
4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,
2,4-Triazole, 4-Hydrogyrosine-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl- 1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, 3-
Examples of the present invention include sodium (5-mercaptotetrazole) -benzenesulfonate, N-methyl-N '-[3- (5-mercaptotetrazolyl) phenyl] urea, and 2-mercapto-4-phenyloxazole. Is not limited to these. The addition amount of these mercapto compounds is preferably in the range of 0.0001 to 1 mol per mol of silver in the emulsion layer (image forming layer), and more preferably per mol of silver.
It is in the amount of 0.001 to 0.3 mol.

In the image forming layer (photosensitive layer) in the present invention, a polyhydric alcohol (for example, glycerin and diol of the type described in US Pat. No. 2,960,404) as a plasticizer and a lubricant, and US Pat. No. 2,588,765 are used. And fatty acids or esters described in US Pat. No. 3,121,060 and silicone resins described in British Patent No. 955,061. The heat-developable image forming material of the present invention may be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. Any polymer may be used as the binder for the surface protective layer.
It is preferable to contain 0 mg / m ² or more and 5 g / m ² or less. The polymer having a carboxyl residue is a natural polymer
(Gelatin, alginic acid, etc.), modified natural polymers (carboxymethyl cellulose, phthalated gelatin, etc.), synthetic polymers (polymethacrylate, polyacrylate, polyalkyl methacrylate / acrylate copolymer, polystyrene / polymethacrylate copolymer, etc.) Is mentioned. The carboxy residue content of such a polymer is preferably from 10 mmol to 1.4 mol per 100 g of the polymer. Further, the carboxylic acid residue may form a salt with an alkali metal ion, an alkaline earth metal ion, an organic cation, or the like.

As the surface protective layer, any anti-adhesion material may be used. Examples of anti-adhesion materials include wax, silica particles, styrene-containing elastomeric block copolymers (e.g., styrene-butadiene-styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate and the like. And mixtures. Further, a crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the surface protective layer. In the image forming layer or the protective layer of the image forming layer in the present invention, U.S. Pat.
Nos. 921, 2,274,782, 2,527,583 and
Light absorbing materials and filter dyes as described in 2,956,879 can be used. Further, a dye can be mordant as described in, for example, US Pat. No. 3,282,699. The amount of the filter dye used is preferably such that the absorbance at the exposure wavelength is 0.1 to 3, and particularly preferably 0.2 to 1.5.

In the photosensitive layer of the heat-developable image forming material of the present invention, various dyes and pigments can be used from the viewpoint of improving color tone and preventing irradiation. Dyes and pigments used in the photosensitive layer may be any, for example, pigments and dyes described in the Color Index, specifically, pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye, oxonol dye, carbocyanine dye , Styryl dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, organic pigments such as phthalocyanine, and inorganic pigments. Preferred dyes used in the present invention are anthraquinone dyes
(For example, compounds 1 to 9 described in JP-A-5-341441, JP-A-5-15-1
65147 described compounds 3-6-18 and 3-23-38, etc.), azomethine dyes (compounds 17-47 described in JP-A-5-341441), indoaniline dyes (e.g. described in JP-A-5-289227) Compounds 11 to 19, compound 47 described in JP-A-5-341441, compounds 2-10 to 11 described in JP-A-5-165147) and azo dyes (compounds 10 to 16 described in JP-A-5-341441) are included. No. As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds used is determined by the desired absorption, but generally 1 m
It is preferable to use 1 μg or more and 1 g or less per ² .

The heat-developable image-forming material of the present invention has at least one photosensitive layer (image-forming layer) containing a silver halide emulsion on one side of a support, and has a back layer on the other side. It is preferably a so-called single-sided image forming material. In the present invention, the back layer preferably has a maximum absorption in a desired range of about 0.3 or more and 2.0 or less. When the desired range is 750 to 1400 nm, the optical density at 750 to 360 nm is preferably 0.005 or more and less than 0.5,
It is more preferable that the antihalation layer has an optical density of 0.001 or more and less than 0.3. When the desired range is 750 nm or less, the maximum absorption of the desired range before image formation is 0.3 or more and 2.0 or less, and further after image formation.
It is preferable that the antihalation layer has an optical density of from 360 to 750 nm of from 0.005 to less than 0.3. The method for lowering the optical density after image formation to the above range is not particularly limited. For example, as described in Belgian Patent No. 733,706, a method in which the density of a dye is reduced by decolorization by heating, And a method of decreasing the density by decoloring by light irradiation described in JP-A-17833.

When antihalation dyes are used in the present invention, such dyes have the desired absorption in the desired range,
Any compound may be used as long as it has a sufficiently low absorption in the visible region after the treatment and a desirable absorbance spectrum of the back layer is obtained. For example, the following are disclosed, but the present invention is not limited thereto. As a single dye, JP-A-59-56458, JP-A-2-216140,
No. 7-13295, No. 7-11432, U.S. Pat.No.5,380,635, JP-A-2-688539, page 13, lower left column, line 1 to line 14,
The lower left column of the page, line 9, from the lower left column of page 14 of JP-A-3-24539
There are compounds described in the lower right column of page 16, and as dyes which can be decolorized by treatment, JP-A Nos. 52-139136, 53-132334, 56-50148.
No. 0, No. 57-16060, No. 57-68831, No. 57-101835, No.
No. 59-182436, JP-A-7-36145, 7-199409
No. 48-33692, No. 50-16648, Japanese Patent Publication No. 2-41734, U.S. Pat.Nos. 4,088,497, 4,283,487, 4,548,896, 5,1
There is 87,049.

In the present invention, suitable binders for the back layer are transparent or translucent, generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as gelatin, gum arabic, and poly (vinyl). (Alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (Styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinylacetal) s (e.g., poly (vinylformal) and poly (vinylformal)).
(Vinyl butyral)), poly (ester) s, poly (urethanes), phenoxy resin, poly (vinylidene chloride), poly (vinylidene chloride)
(Epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and poly (amides). The binder may be coated from water or an organic solvent or emulsion.

When the heat-developable image-forming material of the present invention is a single-sided image-forming material, it may be provided with a surface protective layer and / or a back layer or a back layer of a photosensitive emulsion layer (image forming layer) for improving transportability. A matting agent may be added to the surface protective layer. The matting agent is generally fine particles of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, U.S. Patent Nos. 1,939,213 and 2,70
1,245, 2,322,037, 3,262,782, 3,539,344
No. 3,767,448 No., organic matting agents described in each specification such as No. 1,260,772, No. 2,192,241, No. 3,257,206,
Inorganic matting agents well-known in the art, such as inorganic matting agents described in the specifications of JP-A Nos. 3,370,951, 3,523,022, and 3,769,020 can be used. For example, specifically, examples of organic compounds that can be used as a matting agent include, as examples of water-dispersible vinyl polymers, polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, and polystyrene. , Styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc., examples of cellulose derivatives such as methylcellulose, cellulose acetate, cellulose acetate propionate, and starch derivatives such as carboxy starch, carboxynitrophenyl Gelatin hardened with a known hardener such as starch, urea-formaldehyde-starch reactant, and hardened gelatin formed into microcapsule hollow granules by coacervate hardening are preferably used. Can be. Examples of the inorganic compound include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, and diatomaceous earth. The above matting agents can be used by mixing different types of substances as necessary.
The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In carrying out the present invention
It is preferable to use one having a particle size of 0.1 μm to 30 μm. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze and surface gloss of the image forming material, the particle size, shape, and particle size distribution should be adjusted as necessary during the preparation of the matting agent or by mixing a plurality of matting agents. Is preferred.

In the present invention, it is a preferred embodiment to add a matting agent to the back layer. The matting degree of the back layer is preferably a Beck smoothness of 1200 seconds or less and 10 seconds or more, more preferably 700 seconds or less and 50 seconds or more. It is.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the image forming material, a layer functioning as the outermost surface layer, or a layer close to the outer surface, and a layer functioning as a so-called protective layer. Is preferably contained. The matte degree of the emulsion surface protective layer may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably from 500 seconds to 10,000 seconds, and particularly preferably from 500 seconds to 2,000 seconds.

The heat-developable photographic emulsion used in the present invention includes:
Configure one or more layers on the support. One layer must contain additional optional materials such as organic silver salts, silver halides, developers and binders, and toning agents, coating aids and other auxiliaries. The two-layer configuration is that the first emulsion layer (usually the layer adjacent to the support) contains an organic silver salt and silver halide, and the second layer or both layers do not contain some other components. No. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and may include all components in a single layer as described in U.S. Pat.No. 4,708,928. Is also good. In the case of a multi-dye, multi-color photothermographic material, each emulsion layer generally has a functional or non-functional layer between the emulsion layers (photosensitive layer), as described in U.S. Pat. No. 4,460,681. Are kept distinct from each other by using the barrier layer. U.S. Pat.No. 4,460,681 and U.S. Pat.
(ckside resistive heating layer) can also be used in the photothermographic image system.

In the heat-developable image forming material of the present invention, a hardener may be used for each layer such as an image forming layer (photosensitive layer), a protective layer and a back layer. Examples of hardeners include U.S. Pat.
No. 281,060, polyisocyanates described in JP-A-6-208193, epoxy compounds described in U.S. Pat. And the like are used. A surfactant may be used in the heat-developable image forming material of the present invention for the purpose of improving coating properties and charging. As the surfactant, any surfactant such as nonionic, anionic, cationic, and fluorine can be used as appropriate. Specifically, JP-A-62-170950, a fluoropolymer surfactant described in U.S. Patent No. 5,380,644, JP-A-60-244945
JP-A-63-188135, a fluorine-based surfactant described in JP-A-63-188135, a polysiloxane-based surfactant described in U.S. Pat. Surfactants and the like.

In the present invention, the photographic emulsion for thermal development can be generally coated on various supports. Typical supports include polyester films, primed polyester films, poly (ethylene terephthalate) films, polyethylene naphthalate films, cellulose nitrate films, cellulose ester films, poly (vinyl acetal) films, polycarbonate films and related or resinous Materials, as well as glass,
Including paper, metal, etc. Flexible substrates, particularly coated with baryta and / or partially acetylated α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymers A paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent. Among them, biaxially stretched polyethylene terephthalate (PET) of about 75 to 200 μm is particularly preferred. On the other hand, when a plastic film is passed through a heat developing machine at a temperature of 80 ° C. or higher, the dimensions of the film generally expand and contract. When the processed material is used for printing plate making, this expansion and contraction becomes a serious problem when performing precision multicolor printing. Therefore, in the present invention, it is preferable to use a film having a small dimensional change, which is designed to reduce internal strain remaining in the film at the time of biaxial stretching and eliminate thermal shrinkage distortion generated during thermal development. For example,
Polyethylene terephthalate or the like, which is heat-treated at 100 ° C. to 210 ° C. before applying the photographic emulsion for thermal development, is preferably used. Those having a high glass transition temperature are also preferable, and polyether ethyl ketone, polystyrene, polysulfone, polyethersulfone, polyarylate, polycarbonate and the like can be used.

The heat-developable image-forming material of the present invention may contain, for example, a soluble salt (for example, chloride or nitrate), a deposited metal layer, US Pat. No. 2,861,056 and US Pat.
No. 206,312 or a layer containing an insoluble inorganic salt as described in U.S. Pat. May be provided. As a method for obtaining a color image using the heat-developable image forming material of the present invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to 11 left column, line 40. Further, as a stabilizer for a color dye image, British Patent No. 1,326,889, U.S. Patent No. 3,432,300,
Nos. 3,698,909, 3,574,627, 3,573,050, 3,764,337 and 4,042,394.

The photothermographic emulsions used in this invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. . If desired, two or more layers can be coated simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095. Additional layers in the heat-developable imaging element of this invention, such as a dye-receiving layer for receiving a migrating dye image, an opacifying layer if reflective printing is desired, a protective topcoat layer and those known in the photothermographic art. It may include a primer layer and the like. It is preferable that the image forming material of the present invention can form an image with only one image forming material, and it is preferable that a functional layer such as an image receiving layer necessary for image formation does not become another image forming material.

The heat-developable image-forming material of the present invention may be developed by any method, but is usually developed by elevating the temperature of the image-wise exposed image-forming material. As a preferred embodiment of the heat developing machine used, as a type in which the heat-developable image forming material is brought into contact with a heat source such as a heat roller or a heat drum, Japanese Patent Publication No. 5-56499, Patent Publication No. 684453, JP-A-9-292695, JP-A-9-297385 and International Publication WO
No. 95/30934, as a non-contact type, JP-A-7-13294, WO 97/28489, and 97/2848
Nos. 8 and 97/28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The development time is preferably from 1 to 180 seconds, more preferably from 10 to 90 seconds.

As a method for preventing the processing unevenness due to the dimensional change during the heat development of the heat-developable image-forming material of the present invention,
A method in which an image is not formed at a temperature of 80 ° C. or more and less than 115 ° C. (preferably 113 ° C. or less), heated for 5 seconds or more, and then thermally developed at 110 ° C. or more (preferably 130 ° C. or less) to form an image ( A so-called multi-stage heating method) is effective. The image forming material of the present invention may be exposed by any method,
Laser light is preferred as the exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used.

The image forming material of the present invention has a low haze at the time of exposure and tends to cause interference fringes. Examples of this interference fringe prevention technology include a technology in which a laser beam is obliquely incident on an image forming material as disclosed in JP-A-5-113548 and a multi-mode disclosed in WO95 / 31754 and the like. Methods using lasers are known, and it is preferable to use these techniques. To expose the image forming material of the present invention, SPIE vol.169 Laser Printing 116-128
As disclosed in, for example, page (1979), JP-A-4-51043, and WO95 / 31754, exposure is preferably performed so that laser beams overlap each other so that scanning lines are not visible.

FIG. 1 shows an example of the configuration of a heat developing machine used in the heat developing process of the heat-developable image forming material of the present invention. FIG. 1 is a side view of the heat developing machine. A transfer endless belt 4 suspended by a plurality of feed rollers 3 is pressed against the peripheral surface of a cylindrical heat drum 2 containing a halogen lamp 1 as a heat source of a heating means therein, and the endless belt 4 and the heat drum 2 is conveyed with the heat-developable image forming material 5 interposed therebetween. While being transported, the heat-developable image forming material 5 is heated to a development temperature, and heat development is performed. In this case, the orientation of the lamp is optimized, and the temperature control in the width direction is performed accurately. A correction guide plate for correcting the heat development forming material 5 released from the curvature of the peripheral surface of the heat drum 2 into a flat shape near the outlet 6 from which the heat development image forming material 5 is sent out between the heat drum 2 and the endless belt 4. 7 are provided. In the vicinity of the correction guide plate 7, the ambient temperature is adjusted so that the temperature of the heat-developable image forming material 5 does not become lower than a predetermined temperature.

A pair of feed rollers 8 for feeding the heat-developable image-forming material 5 is provided downstream of the outlet 6, and the heat-developable image-forming material 5 is placed downstream thereof adjacent to the pair of feed rollers 8. A pair of flat guide plates 9 for guiding while being maintained is installed, and further downstream thereof, another pair of feed rollers 10 is installed adjacent to the flat guide plate 9. The flat guide plate 9 has such a length that the heat-developable image-forming material 5 is cooled while the heat-developable image-forming material 5 is conveyed therebetween. That is, during this time, the heat-developable image forming material 5 is cooled until the temperature thereof becomes 30 ° C. or less.
As this cooling means, a cooling fan 11 is provided. As described above, the description has been given according to the illustrated example.
For example, the thermal developing machine used in the present invention, such as that described in JP-A-7-13294, may have various configurations. Further, in the case of the multi-stage heating method preferably used in the present invention, in the above-described apparatus, two or more heat sources having different heating temperatures may be provided, and heating may be performed continuously at different temperatures.

[0131]

The present invention will be described more specifically with reference to the following examples. The materials, amounts, proportions,
The operation and the like can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. (Example 1) The compounds used in Example 1 are shown below.

[0132]

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[0133]

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[0134]

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[0135]

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[0136] 1. Preparation of Organic Acid Silver Emulsion A 933 g of behenic acid was added to 12 liters of water, and while keeping at 90 ° C., a solution prepared by dissolving 48 g of sodium hydroxide and 63 g of sodium carbonate in 1.5 liters of water was added. After stirring for 30 minutes
The temperature was adjusted to 50 ° C., 1.1 L of a 1% aqueous solution of N-bromosuccinimide was added, and 2.3 L of a 17% aqueous solution of silver nitrate were gradually added with stirring. Furthermore, the liquid temperature was set to 35 ° C., 1.5 liters of a 2% aqueous solution of potassium bromide was added over 2 minutes with stirring, and the mixture was stirred for 30 minutes, and 2.4 liters of a 1% aqueous solution of N-bromosuccinimide was added. While stirring this aqueous mixture, 3300 g of a 1.2 wt% polyvinyl acetate butyl acetate solution
Was added and left standing for 10 minutes to separate into two layers, the aqueous layer was removed, and the remaining gel was washed twice with water. The gel mixture of silver behenate and silver bromide thus obtained was dispersed in 1800 g of a 2.6% 2-butanone solution of polyvinyl butyral (Denka Butyral # 3000-K, manufactured by Denki Kagaku Kogyo Co., Ltd.), and further dispersed in polyvinyl butyral ( Japan Monsanto
Butvar B-76 manufactured by Co., Ltd.) 600 g, isopropyl alcohol 3
This was dispersed together with 00 g to obtain an organic acid silver salt emulsion (acicular particles having an average minor axis of 0.05 μm, an average major axis of 1.2 μm, and a coefficient of variation of 25%).

[0137] 2. Preparation of Emulsion Layer Coating Solution A Each chemical was added to the above-obtained organic acid silver emulsion in the following amount per mole of silver. At 25 ° C, 520m of sensitizing dye A
g, compound (C-1) 1.70 g, 4-chlorobenzophenone-2-carboxylic acid (C-2) 21.5 g, calcium bromide dihydrate 0.90
g, 2-butanone 580 g and dimethylformamide 220 g were added with stirring and left for 3 hours. Then, the 1,1-bis (2-
(Hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (C-3) 160 g, Exemplified compound B-42 as a contrast agent
2.1 g, a polymer compound having a repeating unit derived from a monomer represented by the formula (1) or a comparative compound, the kind and amount shown in Table 2, dye (C-4) 1.11 g, sumidur N350
0 (Sumitomo Bayer Urethane Polyisocyanate) 6.4
5 g, Megafax F-176P (a fluorinated surfactant manufactured by Dainippon Ink and Chemicals, Inc.) 0.60 g, 2-butanone 590
g and 10 g of methyl isobutyl ketone were added with stirring.

[0138] 3. Preparation of Emulsion Surface Protective Layer Coating Solution A 65 g CAB171-15S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.), 5.6 g phthalazine (C-5), 1.91 g tetrachlorophthalic acid (C-6), 4-methylphthalate Acid (C-7) 2.6
g, 0.67 g of tetrachlorophthalic anhydride (C-8), 0.36 g of Megafax F-176P, 2 g of Sildex H31 (average spherical silica size 3 μm manufactured by Dokai Chemical Co., Ltd.), and 2-butanone 1050
g and 50 g of dimethylformamide.

[0139] 4. Preparation of a support having a back surface 6 g of polyvinyl butyral (Denka Butyral # 4000-2 manufactured by Denki Kagaku Kogyo KK), 0.2 g of Sildex H121 (average size of spherical silica 12 μm manufactured by Dokai Chemical Co., Ltd.), 0.2 g of Sildex H
0.2 g of 51 (Square silica average particle size 5μm, Dokai Chemical)
It was added to 0.1 g of Megafax F-176P and 64 g of 2-propanol with stirring to dissolve and mix. In addition, 420m
A mixed solution of g of dye A in 10 g of methanol and 20 g of acetone and a solution of 0.8 g of 3-isocyanatomethyl-3,5,5-trimethylhexyl isocyanate in 6 g of ethyl acetate were added to prepare a coating solution. A back surface coating solution was applied on a polyethylene terephthalate film having a moisture-proof undercoat containing vinylidene chloride on both sides so as to have an optical density of 0.7 at 780 nm. After silver emulsion layer coating liquid prepared support on as described above was coated to a 1.6 g / m ^2, as the emulsion surface protective layer coating solution onto the emulsion surface a dry thickness of 2.3μm Applied.

[0140] 5. Evaluation of photographic performance Exposure to xenon flash light with an emission time of 10 ^-4 sec through a step wedge through an interference filter having a peak at 780 nm, processing at 117 ° C for 20 seconds (development), and heating at 120 ° C for 20 seconds
After processing for 2 seconds, the obtained image was evaluated with a densitometer. The measurement results were Dmax, fog (Dmin), and sensitivity (Dmin
(The reciprocal of the ratio of the exposure amount giving a density higher than 1.5). The sensitivity was shown as a relative value with the sensitivity of sample No. 101 in Table 1 as 100. The gradient of the straight line connecting the points of density 0.3 and 3.0 in the characteristic curve is shown as gradation γ. Table 2 shows the results.

[0141]

[Table 2]

[0142] 6. Result In sample Nos. 101 to 103, fog was high at 117 ° C development and 120 ° C.
In development, fog is further increased, and the sensitivity is greatly increased. It can be seen that in the samples Nos. 104 to 114 of the present invention, the increase in fog and the change in sensitivity due to the change in the developing temperature are suppressed to a small level.

Example 2 The compounds used in Example 2 are shown below.

[0144]

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1. Preparation of silver halide emulsion (Emulsion A) 11 g of phthalated gelatin and 30 m of potassium bromide in 700 ml of water
g, dissolving 10 mg of sodium benzenethiosulfonate, adjusting the pH to 5.0 at a temperature of 55 ° C., and keeping an aqueous solution containing 18.6 g of silver nitrate and an aqueous solution containing potassium bromide at 1 mol / liter at pAg 7.7. It was added over 6 minutes and 30 seconds by the control double jet method. Then, 476 ml of an aqueous solution containing 55.5 g of silver nitrate and a halogen salt aqueous solution containing 1 mol / l of potassium bromide were added by a control double jet method over 28 minutes and 30 seconds while keeping the pAg at 7.7. afterwards
The pH was lowered to cause coagulation sedimentation and desalting treatment.
17g, deionized gelatin (calcium content 20ppm
23.7 g) were added to adjust the pH to 5.9 and pAg8.0. The obtained particles have an average particle size of 0.11 μm and a projected area variation coefficient of 8
%, (100) face ratio of 93%. The silver halide grains thus obtained were heated to 60 ° C., and 76 μmol of sodium benzenethiosulfonate was added per 1 mol of silver.
One minute later, 154 μmol of sodium thiosulfate was added, and the mixture was aged for 100 minutes. After that, keep the temperature at 40 ° C,
6.4 × 10 ^-4 moles of sensitizing dye B and 6.4 × 10 ^-3 moles of compound B were added with stirring, and after 20 minutes, the mixture was rapidly cooled to 30 ° C. to complete the preparation of silver halide emulsion A. did.

[0146] 2. Preparation of organic acid silver dispersion (organic acid silver A) 6.1 g of arachidic acid, 37.6 g of behenic acid, 700 ml of distilled water, tert
-Butanol 70ml, 1N-NaOH aqueous solution 123ml mixed, 75 ℃
The mixture was stirred for 1 hour to react, and the temperature was lowered to 65 ° C. Then, 112.5 ml of an aqueous solution of 22 g of silver nitrate was added over 45 seconds, and
It was left for 5 minutes, and the temperature was lowered to 30 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid content thus obtained is treated as a wet cake without drying, and the dry solid content is 100 g.
Considerable wet cake, polyvinyl alcohol
(Product name: PVA-205) Add 5g and water to make the total amount 500
g and then predispersed with a homomixer. Next, the pressure of the predispersed undiluted solution was adjusted to 1750 kg / cm ² by using a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber). This was repeated to obtain an organic acid silver dispersion A. The organic acid silver particles contained in the organic acid silver dispersion thus obtained were needle-like particles having an average minor axis of 0.04 μm, an average major axis of 0.8 μm, and a variation coefficient of 30%. Particle size measurements are available from Malvern Instruments Lt.
d. Performed with MasterSizerX. For cooling operation, install a coiled heat exchanger before and after the interaction chamber, respectively.
The desired dispersion temperature was set by adjusting the temperature of the refrigerant. Thus, organic acid silver A having a silver behenate content of 85 mol% was prepared.
Was prepared.

[0147] 3. 1,1-bis (2-hydroxy-3,5-dimethyl
Ruphenyl) -3,5,5-trimethylhexane
Preparation of powder 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-
To 70 g of trimethylhexane, 14 g of MP-203 of Kuraray Co., Ltd. and 266 ml of water were added and stirred well,
The slurry was left for 3 hours. Thereafter, 960 g of 0.5 mm zirconia silicate beads were prepared, put into a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 5 hours to obtain a dispersion of solid fine particles of a reducing agent. Prepared. The particle size is 80 wt% of the particles 0.3
It was not less than μm and not more than 1.0 μm.

[0148] 4. Derived from monomer represented by formula (1)
Fine Particles of Polymer Compounds Having Repeating Units
Kuraray the child dispersed polymer compound having a repeating unit derived from a monomer represented by Preparation formula (1) of the Composition Example P-5 30 g (Ltd.)
4 g of MP-203, 0.25 g of compound C, and 66 parts of water
g, and stirred well, and then 200 g of 0.5 mm zirconia silicate beads were prepared and placed in a vessel together with the slurry, and the dispersion machine (1 / 16G sand grinder mill:
The mixture was dispersed for 5 hours by using IMEX Co., Ltd. to prepare a solid fine particle dispersion. The particle diameter is 80% by weight of the particles is 0.3 μm or more and 1.0
μm or less. Other kinds of polymer compounds having a repeating unit derived from the monomer represented by the formula (1) and comparative compounds were dispersed in the same manner as described above to prepare solid fine particle dispersions.

[0149] 5. Preparation of solid fine particle dispersion of ultra-high contrast agent Kuraray Co., Ltd.
2.5 g of PVA-217 and 87.5 ml of water were added, and the mixture was stirred well to form a slurry. Thereafter, a solid was prepared in the same manner as in the preparation of the polymer compound having a repeating unit derived from the monomer represented by the formula (1). A fine particle dispersion was prepared. The particle size is
80 wt% was 0.3 μm or more and 1.0 μm or less.

[0150] 6. Preparation of Emulsion Layer Coating Solution The following binder, material, and silver halide emulsion A were added to 1 mol of silver of the organic acid silver microcrystal dispersion prepared above, and water was added. Liquid. Binder; Luck Star 3307B 470 g as solids (manufactured by Dainippon Ink and Chemicals, Inc .; glass transition temperature of 17 ° C. with SBR latex) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5 , 5-trimethylhexane 110g as solid content Polymer compound having a repeating unit derived from a monomer represented by the formula (1) The amount and type are described in Table 3. Sodium benzenethiosulfonate 0.1g 6-methylbenzotriazole 1.35 g polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) 46 g 6-iso-butylphthalazine 0.12 mol Dye B 0.62 g Silver halide emulsion A 0.05 mol as Ag amount Ultra-high contrast agent Solid dispersion of Exemplified Compound B-42 8.5g for B-42

[0151] 7. Preparation of Coating Solution for Emulsion Surface Protective Layer Polymer latex having a solid content of 27.5 wt% (methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-
Hydroxyethyl methacrylate / acrylic acid = 59/9
/ 26/5/1 copolymer with a glass transition temperature of 55 ° C) 109 g of H ₂
O 3.75 g was added, and benzyl alcohol 4.
5 g, Compound D 0.45 g, Compound E 0.125 g, Compound F 1.70
g, polyvinyl alcohol (Kuraray Co., Ltd., PVA-
217) 0.285 g was added, and further H ₂ O was added to 150 g to prepare a coating solution.

[0182] 8. PET support with backing / priming layer
Preparation of (1) Support PET (intrinsic viscosity) = 0.66 (measured in phenol / tetrachloroethane = 6/4 (weight ratio) at 25 ° C.) using terephthalic acid and ethylene glycol according to a conventional method. Was. After pelletizing this, it was dried at 130 ° C for 4 hours,
After being melted at 00 ° C., the film was extruded from a T-die and quenched to prepare an unstretched film having a thickness of 120 μm after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter.
The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends, and the film was wound at 4.8 kg / cm ² . Thus, width 2.4m, length 3500m, thickness 120
A μm roll was obtained.

(2) Undercoat layer (a) Polymer latex- (1) Styrene / butadiene / hydroxyethyl methacrylate / divinylbenzene = 67/30 / 2.5 / 0.5 (% by weight) 160 mg / m ² 2,4-dichloro-6 -Hydroxy-s-triazine 4 mg / m ² Matting agent (polystyrene, average particle size 2.4 μm) 3 mg / m ² (3) Undercoat layer (b) Alkali-treated gelatin (Ca ²⁺ content 30 ppm, jelly strength 230 g) 50 mg / m ² Dye B Coating amount at which the optical density of 780 nm becomes 1.0 (4) Conductive layer Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) 96 mg / m ² Gelatin 50 mg / m ² Compound A 0.2 mg / m ² Polyoxyethylene Phenyl ether 10 mg / m ² Sumitex resin M-3 18 mg / m ² (Water-soluble melamine compound manufactured by Sumitomo Chemical Co., Ltd.) Dye B Coating amount at which the optical density of 780 nm becomes 1.0 SnO ₂ / Sb (9/1 weight ratio, acicular particles, a long axis / short axis = 20-30; Ishihara Sangyo Co., Ltd.) 120 mg / m ² matting agent (polymethyl Rate, the average particle diameter 5μm) 7mg / m ²

(5) Protective Layer Polymer Latex- (2) Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1 (weight% copolymer) 1000 mg / m ² polystyrene sulfonate (molecular weight: 1000 to 5000) 2.6 mg / m ² cellosol 524 (manufactured by Chuo Yushi Co., Ltd.) 30 mg / m ² Sumitex Resin M-3 218 mg / m ² (water-soluble melamine compound, Sumitomo Chemical Industry Co., Ltd.)

An undercoat layer (a) and an undercoat layer (b) are formed on one side of the support.
Were sequentially applied and dried at 180 ° C. for 4 minutes. Then, a conductive layer and a protective layer are sequentially coated on the opposite side to which the undercoat layer (a) and the undercoat layer (b) have been applied, and dried at 180 ° C. for 30 seconds, respectively, for a PET support having a back / undercoat layer. It was created. With the back / priming layer created in this way
The PET support was placed in a heat treatment zone with a total length of 30 m set at 150 ° C. and transported under its own weight at a tension of 14 g / cm ² and a transport speed of 20 m / min.
Thereafter, the film was passed through a zone at 40 ° C. for 15 seconds, and wound up at a winding tension of 10 kg / cm ² .

[0156] 9. It was applied so that the emulsion layer coating solution on a PET support undercoat layer equipped with a prepared the back / subbing layer of the heat developable image-forming material on the coated silver amount 1.6 g / m ^2. Further, the coating liquid for the emulsion surface protective layer was applied thereon so that the coating amount of the solid content of the polymer latex was 2.0 g / m ² .

[0157] 10. Evaluation of photographic performance (exposure processing) through the coating sample obtained through an interference filter and a step wedge having a peak at 780 nm,
Exposure was performed with xenon flash light having an emission time of ^10-6 seconds. (Heat development processing) The exposed sample is processed by the heat development machine shown in FIG.
Heat development was performed at 117 ° C. for 20 seconds and at 120 ° C. for 20 seconds. In the drum type heat developing machine of FIG. 1, the light distribution of the lamp was optimized, and the temperature control in the width direction was performed at ± 1 ° C. Further, the temperature of the heat-developable image forming material in the vicinity of the correction guide plate 7 is 90 °.
The ambient temperature was adjusted so that the temperature did not fall below ℃. (Evaluation of photographic performance) Macbeth TD904
The measurement was performed using a densitometer (visible density). The result of the measurement is Dmax,
Evaluation was made based on fog (Dmin), sensitivity (reciprocal of the ratio of the exposure amount giving a density 1.5 higher than Dmin), and gradation (contrast). The sensitivity of sample No. 201 was set to 100. Contrast was represented by the slope of a straight line connecting points of density 0.3 and 3.0, with the logarithm of the exposure amount as the horizontal axis.

[0158]

[Table 3]

(Results) By using the specific compounds used in the present invention in combination, a heat-developable image-forming material which satisfies the super-high contrast property, is hardly fogged, and has good fog resistance even when the developing temperature fluctuates. Was.

(Example 3) Exemplified compounds P-5 and P-5 of polymer compounds having a repeating unit derived from the monomer represented by the formula (1) and the polyhalogen comparative compounds-1 to 3 of Example 1 -9 and P-13 were heated at 160 ° C. for 60 minutes, and the weight change before and after heating was examined. As a result, about 20% of the weight change was observed for Comparative Compounds 1 and 2, and about 50% for the Comparative Compound-3. Is exemplified compounds P-5, P-9 and P-
In No. 13, no change in weight was observed.

[0161]

According to the present invention, by using a polyhalogen compound having almost no volatility, the adverse effect on the human body and the environment is small, and the printing is hard and the fog is extremely small even when the heat development conditions fluctuate. A heat-developable ultrahigh contrast image forming material suitable for plate making is obtained.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration example of a heat developing machine used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Halogen lamp 2 Heat drum 3 Feed roller 4 Endless belt 5 Thermal development image forming material 6 Exit 7 Guide plate 8 Feed roller pair 9 Flat guide plate 10 Feed roller pair 11 Cooling fan

Claims (5)

[Claims] 1. At least one surface of a support,
It contains (a) a reducible silver salt, (b) a reducing agent, (c) a binder, and (d) a polymer having a repeating unit derived from a monomer of the polyhalogen compound represented by the formula (1). A heat-developable image forming material, comprising: Embedded image [In the formula (1), Ht represents an aromatic ring group or a heterocyclic group, E ₁ and E ₂ each independently represent a halogen atom, and W represents a hydrogen atom or an electron-withdrawing group. R represents a substituent, and k represents an integer of 0 to 4. Q represents an ethylenically unsaturated group or a group having an ethylenically unsaturated group, and m represents an integer of 1 to 3. n represents an integer of 1 or 2. When k, m and n represent an integer of 2 or more, the groups present in 2 or more may be the same or different. ] 2. The heat-developable image forming material according to claim 1, further comprising (e) photosensitive silver halide on the same surface. 3. In the above formula (1), E ₁ , E ₂ and W
3. The heat-developable image-forming material according to claim 1, wherein is a bromine atom. 4. The heat-developable image forming material according to claim 1, further comprising (f) a super-high contrast agent on the same surface. 5. The heat-developable image-forming material according to claim 4, wherein the super-high contrast agent is selected from the compounds represented by formulas (2), (3) and (4). Embedded image [In the formula (2), R ₁ , R ₂ and R ₃ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (2), R ₁ and Z, R ₂ and R ₃ , R ₁ and R ₂ , and R ₃ and Z may be mutually bonded to form a cyclic structure. In equation (3),
R ₄ represents a substituent. In the formula (4), X and Y each independently represent a hydrogen atom or a substituent;
Each independently represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or a heterocyclic amino group. In the formula (4), X and Y, and A and B may be bonded to each other to form a cyclic structure. ]