JPH04321044A - Image forming method - Google Patents

Abstract

PURPOSE:To prevent the infiltration of a soln. (contg. a reducing agent and a part of dyes) into the under coat layers and base of a photosensitive material and to prevent the degradation in developability and dye transfer rate as well as to improve curling and the film deposition characteristic of photosensitive layers. CONSTITUTION:This image forming method consists in subjecting the heat developable photosensitive material having at least one layer of the under coat layers contg. hydrophobic resins on the base and having the photosensitive layers contg. hydrophilic binders, silver halide and dye donative materials thereon to imagewise exposing, then superposing this material on a dye image receiving material and simultaneously executing heat development and dye transfer or superposing this heat developable photosensitive material on the dye image receiving material after heat development and diffusion transferring the dyes onto the dye image receiving material. The permeation rate of the hot water through the under coat layers in the above-mentioned method is <=20g/m<2>. The stage for making heat development by superposing the heat developable photosensitive material and the dye image receiving material on each other or the stage for transferring the diffusive dyes to the image receiving material is executed in the presence of a solvent.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to an image forming method using a heat-developable photosensitive material, and more specifically, the developability during heat development,
The present invention relates to an image forming method with improved transferability.

0002

BACKGROUND OF THE INVENTION Heat development processing in which the development step is performed by heating is well known, and methods for producing black and white images and color images are known. Furthermore, so-called transfer-type heat-developable photosensitive materials, in which an image obtained by heat development is transferred from the photosensitive material to an image receiving layer, are also well known.

Heat-developable photosensitive materials usually contain a binder, a photosensitive silver halide emulsion, a reducing agent, and, if necessary, a dye-providing substance, an organic silver salt, and various other photographic additives on a support. are doing. In addition, in the transfer type heat-developable photosensitive material, there are cases in which the photosensitive material has an image-receiving layer capable of receiving silver or dyes, and cases in which the photosensitive material has an image-receiving layer capable of receiving silver or dyes separately from the photosensitive material. An image receiving member may be used together.

These heat-developable light-sensitive materials do not require processing solutions such as developing solutions and fixers used in general photographic light-sensitive materials; however, in the heat development and/or transfer process,
Maintained at a high temperature of 0.000C, some unforeseen disadvantages occur.

One such problem is that developed samples of heat-developable light-sensitive materials often suffer from unexplained deterioration in developability and dye transferability.

In order to elucidate the cause of this, the inventors of the present invention conducted a detailed investigation of heat-developable photosensitive materials and image-receiving materials that had been developed, and found that under the high-temperature conditions during heat development, the photosensitive layer originally remained in the photosensitive layer and the heat-developable transfer occurred. It has been found that a part of the solvent that should contribute to and promote the process permeates into the subbing layer and support of the heat-developable photosensitive material, resulting in a decrease in heat developability and dye transfer properties. Furthermore, in so-called development and transfer separation systems, in which only a heat-developable photosensitive material is thermally developed and the released or formed dye is transferred to an image-receiving material in a separate process, the photosensitive layer and image-receiving layer do not come into contact during the heat development process. It has been found that as a result of the accelerated penetration of the solvent into the undercoat layer and support, these effects are more serious than in a system in which thermal development and transfer are performed simultaneously. Based on these results, in image forming methods that use solvents in the development and/or transfer steps, it is important to avoid using high-temperature solvents (
(containing a part of the reducing agent and dye) penetrates into the subbing layer or penetrates through the subbing layer and into the support, reducing developability and significantly reducing the transferability of the resulting dye. It was found that it decreased.

[0007] In order to improve these drawbacks, it is conceivable to provide a subbing layer made of a hydrophobic resin on the support.

[0008] JP-A-63-38934, JP-A No. 63-17
No. 3043 and JP-A No. 1-248146 disclose a technique for improving the occurrence of uneven processing by providing a hydrophobic resin layer on a paper support to prevent components from being absorbed into the support when coating a photosensitive layer. has been done. Although this method certainly prevents components in the photosensitive layer solution from penetrating during coating, it is hardly effective at high temperatures during heat development, and therefore It was found that penetration into the body occurred and a decrease in developability could not be prevented. It was also found that because the hydrophobic resin layer is thick, curling increases and film adhesion with the photosensitive layer tends to decrease.

[0009]

OBJECT OF THE INVENTION In order to solve the above-mentioned problems, the object of the present invention is to prevent the solvent (containing part of the reducing agent and dye) from being absorbed into the subbing layer or support of the photosensitive material during the high-temperature conditions of thermal development. It is an object of the present invention to provide a heat-developable photosensitive material and an image forming method that prevent permeation, prevent deterioration of developability and dye transfer rate, and improve curling and film adhesion of a photosensitive layer.

0010

[Structure of the Invention] The above-mentioned object of the present invention is to have at least one subbing layer containing a hydrophobic resin on a support, and a hydrophilic binder, silver halide, and a dye-donating substance on the subbing layer. A heat-developable photosensitive material having a photosensitive layer is subjected to imagewise exposure and then overlaid with a dye image-receiving material to perform heat development and dye transfer simultaneously, or alternatively, the heat-developable photosensitive material is thermally developed and then overlaid with a dye image-receiving material. In addition, in an image forming method in which a dye is diffusely transferred to a dye image-receiving material, the amount of hot water permeation of the subbing layer is 20 g/m2 or less or 10 g/m2 or less, and the above-mentioned photothermographic material and the above-mentioned dye image-receiving material are This is achieved by an image forming method characterized in that the step of superimposing and thermal development or the step of transferring a diffusible dye to an image-receiving material is carried out in the presence of a solvent.

[0011] Preferable embodiments of the present invention include the following.

[0012] The Tg of the hydrophobic resin is 50°C or higher or 60°C.
Must be above ℃. The support is a paper support, and the hydrophobic resin of the undercoat layer has a lower Tg than that of the undercoat layer on the side closer to the support, or It is preferred that the layer furthest from the support contains at least one hydrophilic resin. The amount of hydrophobic resin used in the undercoat layer is 0.1 to 10 g/m2, or the amount of hydrophilic resin used in the undercoat layer is 0.1 to 10 g/m2.
It is preferable that it is 01-10g/m2.

The present invention will be explained in detail below. The undercoat layer containing a hydrophobic polymer used in the present invention has a hot water permeation rate of 20 g/m2 or less. The amount of hot water permeation conforms to the cup water absorption method specified in JIS-P8140, and is characterized by using hot water with a temperature of 90° C. or higher.

[0014] The amount of hot water permeated in the present invention is approximately 150×150
A rubber mat with a thickness of about 2 mm was placed on a heat-resistant plastic plywood board with a size of about 130 x 130 mm, which was measured by weight.
Place a piece of subtracted paper with a diameter of about 112.8 mm (area 100 cm2), a height of about 25 mm, and a wall thickness of about 8 mm. Pour 50cc of water into the ring,
After leaving it for 60 seconds, discard the hot water, thoroughly remove the moisture on the surface with absorbent paper, measure the weight of the subtracted test piece, and multiply the difference (g) from the initial weight by 100. Transmission amount (
g/m2).

The hydrophobic polymer used in the undercoat layer of the present invention can be appropriately selected from known polymers, such as polyvinyl chloride, polyvinylidene chloride, polystyrene, polyurethane, polyester, polycarbonate, polyamide, and polyimide. Polymers such as polyacrylic acid, polyacrylic ester, polyacrylate, polyvinyl acetate, polymethacrylic ester, polyether ketone, polyether imide, polyether sulfone, polyether ether ketone, polyphenylene ether, polyphenylene sulfide, etc. Can be mentioned.

[0016] The hydrophobic polymer of the present invention can also be used as an alloy or a blend of two or more types. Further, the hydrophobic polymer of the present invention may be a copolymerizable polymer having two or more types of repeating units. However, even when the heat-developable photosensitive material of the present invention contains a copolymerizable polymer, in addition to the copolymerizable polymer, another hydrophobic polymer is added to the undercoat layer in a mixture with the copolymerizable polymer. It is necessary to exist as a.

Examples of the above-mentioned copolymerizable polymers include those obtained by copolymerization by appropriately combining the following copolymerizable monomers.

{Specific examples of copolymerizable monomers} a: acrylic acid, methacrylic acid b: acrylic ester (methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, etc.) c: methacrylic ester ( Methyl methacrylate, n-butyl methacrylate, phenyl methacrylate, hydroxyethyl methacrylate, etc.) d: Vinyl esters (vinyl acetate, vinyl butyrate, vinyl salicylate, etc.) e: Olefins (dicyclopentadiene, butadiene, 1-butene) , 3-methylpentene, vinyl chloride, vinylidene chloride, etc.) f: Styrenes (styrene, methylstyrene, i-propylstyrene, chlorstyrene, etc.) g: Croton sun esters (butyl crotonate, hexyl crotonate, etc.) h: Itaconate diesters (diethyl itaconate, dibutyl itaconate, etc.) i: Maleate diesters (diethyl maleate, etc.)
j: Fumaric acid diesters (dimethyl fumarate, etc.) k:
Acrylamides (acrylamide, ethyl acrylamide, hydroxyl methyl acrylamide, methoxyethylacrylamide, etc.) l: Methacrylamide (methyl methacrylamide, ethyl methacrylamide, t-butyl methacrylamide) m: Allyls (allyl acetate, allyl laurate, etc.) n:
Vinyl ethers (methyl vinyl ether, butyl vinyl ether, etc.) o: Vinyl heterocyclic compounds (vinylpyridine, N-vinylimidazole, N-vinyloxazolidone, N-vinylpyrrolidone, etc.) p: Glycidyl esters (glycidyl acrylate,
(glycidyl methacrylate, etc.) q: Unsaturated nitriles (acrylonitrile, etc.) r: Multifunctional monomers (divinylbenzene, ethylene glycol dimethacrylate, etc.) The hydrophobic polymer used in the subbing layer of the present invention is selected from known polymers. Although they can be appropriately selected and used, it is preferable that at least one of them has a glass transition temperature equal to or higher than the heat development temperature or dye transfer temperature.

[0019] Thermal development temperature and/or dye transfer temperature is 60°C.
above, preferably 80°C or above, more preferably about 100°C
℃ or higher, at least one of the hydrophobic polymers contained in the undercoat layer of the present invention has a glass transition temperature of 60℃ or higher, preferably 80℃ or higher, and more preferably 1.
It is a polymer that has a temperature of 00°C or higher.

Among such resins, the present invention particularly uses polyphenylene ether, polybutylene terephthalate,
Polyarylate and polyimide are preferred, and polyphenylene ether is most preferably used.

The polyphenylene ether (PPE) particularly preferably used in the present invention is a polycondensate of a phenol compound represented by the following general formula (1) or a polymer obtained by polycondensing a phenol compound represented by the general formula (1) with an alkenyl aroma. Examples include polymers obtained by grafting group compounds, such as those described in JP-A-63-289060.

[0022]

[Chemical formula 1]

[In the formula, R1 represents an alkyl group having 1 to 3 carbon atoms, and R2 and R3 are a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
~3 represents an alkyl group. ] The resin used together with the polyphenylene ether system is preferably polystyrene.

[0024] The undercoat layer is preferably used in the present invention with the hydrophobic polymer (hereinafter referred to as the first polymer) having a glass transition temperature of 60°C or higher, preferably 80°C or higher, particularly preferably 100°C or higher. The type of polymer to be formed (hereinafter referred to as the second polymer) is not particularly limited, but it is preferably a polymer that is compatible with the first polymer in the coating solution forming the undercoat layer. Polystyrene is preferred as the polymer used with the polyphenylene ether system.

The hydrophobic polymer of the present invention can be coated by heating and melting, and can also be coated by dissolving it in an organic solvent or dispersing it in a latex form, but since it is easy to form a film, solvent coating is preferred. preferable.

[0026] Such a polymer cannot be determined unconditionally because the type of organic solvent used in preparing the coating solution has a large influence, but it is possible to select an appropriate second polymer from the combination of the first polymer and organic solvent. of polymers are selected. The ratio (weight ratio) of the first polymer to the second polymer is arbitrary, but preferably the first polymer accounts for 20% or more, more preferably 40% of the total amount of hydrophobic polymers in the undercoat layer. The above is preferable for the effects of the present invention, particularly for preventing a high-temperature solvent from penetrating into the undercoat layer during thermal development or dye transfer.

[0027] Examples of the organic solvent used in the coating solution for forming the subbing layer include acetone, methyl ethyl ketone, methyl propyl ketone, ethyl acetate, chloroform,
Examples include, but are not limited to, methylene chloride, dichloroethane, trichloroethane, phenol, dimethylformamide, toluene, cyclohexane, cyclohexanone, tetrahydrofuran, dioxane, and the like. These may be used alone or in combination of two or more depending on the type of polymer.

[0028] The above hydrophobic polymers can also be a combination of three or more types of hydrophobic polymers. Among these, the third polymer can be a polymer that is compatible with the first and second polymers.

When preparing the coating solution for forming the hydrophobic subbing layer of the heat-developable photosensitive material of the present invention, two or more hydrophobic polymer solids are added to the organic solvent used, and heated if necessary. A uniform coating solution may be obtained by stirring, or each of the individual hydrophobic polymers may be uniformly dissolved individually in an appropriate organic solvent in advance, and then these may be mixed and dissolved. Alternatively, two or more hydrophobic polymers may be mixed in advance in a molten state, added to the organic solvent used in the coating liquid, and dissolved by heating and stirring as necessary. These methods can be further combined as necessary.

In particular, two or more polymers are melted in advance to form a mixed state, and the solid polymer obtained by solidifying after cooling is added to the organic solvent used for the coating solution for the undercoat layer and mixed as necessary. A method in which the first polymer or the second polymer is further added and dissolved is particularly preferably used in the present invention. In this case, a uniform coating surface can be obtained, and moreover, the dye is less likely to diffuse into the subbing layer during thermal development or dye transfer.

In particular, in the present invention, when the first polymer is dissolved alone in the coating liquid for the undercoat layer, it cannot be uniformly dissolved, and it is not possible to dissolve the first polymer in the coating liquid until the second polymer is present. It is most preferable to combine a polymer that can be dissolved with an organic solvent from the viewpoint of preventing the dye from being transferred to the subbing layer.

In the present invention, polyphenylene ether (PPE) is particularly preferred as the first polymer, and polyphenylene ether (PPE) is particularly preferred as the first polymer.
Polystyrene (PS) is preferred as the polymer, but
In such a case, both PPE and PS may be mixed in a molten state in advance, and after cooling, this polymer mixture may be dissolved in an organic solvent such as toluene or dichloroethane and used as a coating solution. Alternatively, PS may be further mixed with the above-mentioned mixed polymer solid of PPE and PS, and this may be added to the above-mentioned organic solvent to dissolve it. In particular, the latter method is preferable because it allows the characteristics of the undercoat layer to be controlled to a certain extent when variations occur between lots of mixed solid polymers.

[0033] The coating liquid for forming the undercoat layer may contain a plasticizer, a surfactant, a curing agent, or the like.

The surfactant is preferably a nonionic surfactant, such as a nonionic compound having an ethylene oxide group or a propylene oxide group in the molecule.

Examples of plasticizers include phthalic acid diesters such as dioctyl phthalate, dibutyl phthalate, diphenyl phthalate and dinonyl phthalate, phosphoric acid esters such as tricresyl phosphate and triphenyl phosphate, and benzoic acid esters such as benzoic acid stearate. kind,
Examples include solid or liquid paraffins, amides such as N,N-dimethylamide, and the like.

Examples of the hardening agent include isocyanate compounds, ethylene tomino compounds, aziridine compounds, active vinyl compounds, and epoxy compounds.

The above-mentioned coating liquid for undercoat layer of the present invention is coated on a paper support by a known method. Specifically, the coating method is dip coating, slide hopper coating, extrusion coating, wire bar coating, gravure coating, air knife coating, etc.

After the coating solution for the subbing layer is coated on the paper support, the organic solvent is removed in a drying process.
At this time, from the viewpoint of uniformity of the film, it is preferable to avoid cooling the film surface temperature by heat of evaporation as much as possible. If the coating surface temperature drops extremely during the drying process, especially in the first half of drying when the solvent evaporation rate is about 70% or less, it may easily cause irregular polymer phase separation in the coating, making it difficult to achieve a uniform coating. It tends to be difficult to obtain a film surface. This problem is particularly serious when the first polymer has no solubility in the organic solvent for the undercoat layer, which is a particularly preferred embodiment of the present invention. Such troubles can be avoided by adjusting the drying temperature conditions so that the coating temperature is 5°C or higher, preferably 10°C or higher, and particularly preferably 20°C or higher during the drying process, especially until the residual amount of solvent reaches 30%. It is necessary to optimize the drying air volume or the method of heat transfer to the web. In particular, such troubles are less likely to occur if the undercoat layer is heated from the opposite side using a roller or the like.

The amount of hydrophobic polymer used in the subbing layer of the present invention is preferably 0.05 to 10 g/m2, preferably 0.05 to 10 g/m2.
．． 1 to 5 g/m2 is more preferred.

If the amount is less than 0.05 g, only a slight effect of the present invention will be obtained, and if it is more than 10 g, curling will increase and costs will increase, which is undesirable.

When the subbing layer of the present invention has two or more layers, it is preferable that the Tg of the hydrophobic polymer on the side closer to the photosensitive layer is lower than the Tg of the hydrophobic polymer on the side closer to the support.

[0042] Furthermore, when the subbing layer of the present invention is two or more layers,
The layer adjacent to the emulsion layer preferably contains a hydrophilic polymer.

Hydrophilic polymers used in the subbing layer of the present invention include polyvinyl butyral, polyvinyl acetate,
Synthetic or natural polymeric substances such as ethyl cellulose, polymethacrylate, polyvinyl alcohol, polyvinylpyrrolidone, gelatin, gelatin derivatives such as phthalated gelatin, cellulose derivatives, proteins, starches, gum arabic, water-soluble polyesters, and latex can be used. can. The amount of the hydrophilic polymer used in the undercoat layer of the present invention is preferably 0.05 to 10 g/m2, more preferably 0.1 g to 5 g/m2.

[0044] By lowering the Tg of the hydrophilic polymer close to the photosensitive layer or containing a hydrophilic polymer, the film adhesion to the photosensitive layer and the curling property of the photosensitive material, which are disadvantages of hydrophobic polymer undercoating, can be improved. be able to.

Before coating the undercoat layer of the present invention, it is preferable to subject the surface of the substrate or coated undercoat layer to a corona discharge treatment. The amount of corona discharge is 0.1 to 300W/
m2・min, preferably 0.5 to 200W/m2・m
It is in.

Examples of the support used in the photothermographic material of the present invention include glass, polypropylene film,
Transparent or opaque synthetic plastic films such as cellulose acetate film, polyethylene terephthalate film, and polyethylene naphthalate film, various coated papers such as art paper, cast coated paper, and baryta paper, and polyethylene resin-coated paper, as well as on these various supports. Examples include supports coated with and cured with electron beam curable resin compositions and UV curable resin compositions.

Among these, various coated papers based on polyethylene terephthalate (PET) film or paper are preferably used from the viewpoint of cost and ease of handling.

The base paper used for the paper support of the photothermographic material of the present invention is mainly made of wood pulp, and if necessary, in addition to the wood pulp, synthetic pulp such as polypropylene or synthetic fibers such as nylon or polyester may be added. Paper is made using
Manufactured. As wood pulp, LBKP, LBSP
, NBKP, NBSP, LDP, NDP, LUKP, N
Any UKP can be used and their ratio can be combined arbitrarily, but LBK with a high short fiber content can be used.
It is preferable to use more of P, NBSP, LBSP, NDP, LDP, etc. However, the ratio of LBSP and/or LDP is preferably 10% by weight or more and 70% by weight or less.

The above pulp is a chemical pulp with few impurities (
Sulfate pulp, sulfite pulp, etc.) are used, and pulp that has been bleached to improve its whiteness is also useful.

The base paper contains sizing agents such as higher fatty acids and alkyl ketene dimers, white contents such as calcium carbonate, talc, clay, kaolin, titanium dioxide, and barium sulfate, and paper strength enhancers such as starch, polyacrylamide, and polyvinyl alcohol. Additives conventionally known for use in photographic base papers, such as optical brighteners, water retention agents such as nylon chloride and polyethylene glycol, dispersants, and softeners such as quaternary ammonium salts, can be used.

[0051] The freeness of the pulp used for paper making is preferably 200 to 500 cc as specified by CSF, and the fiber length after beating is 24 mesh residual weight% and 42 mesh as specified in JIS-P-8207. The sum of the remaining weight% is 3
0 to 70% is preferred. Note that the weight percent of the 4-mesh residue is preferably 20% or less.

The basis weight of the base paper is preferably 30 to 250 g, particularly preferably 50 g to 200 g. The thickness of the base paper is preferably 40 to 250 μm.

[0053] The base paper can also be calendered at the papermaking stage or after viewing to impart high smoothness. The base paper density is generally 0.7 to 1.2 g/m2 (JIS-P-8118). Further, the stiffness of the base paper is preferably 20 to 150 g under the conditions specified in JIS-P-8143.

A surface sizing agent may also be applied to the surface of the base paper, and examples of the surface sizing agent include polyvinyl alcohol, starch, polyacrylamide, alkyl ketene dimer, and the like.

The paper support for the photothermographic material of the present invention may consist only of the above-mentioned base paper, or may have an undercoat layer provided in advance on the side to which the hydrophobic polymer layer is applied. Specifically, it may be so-called coated paper containing organic pigments or inorganic pigments.

Further, a binder, a dispersant, an antifoaming agent, etc. can be added to the undercoat layer if necessary.

Examples of organic pigments and inorganic pigments that can be used in the undercoat layer include kaolin, clay, talc, calcium carbonate, titanium oxide, barium sulfate, and gunjo. In addition, as a binder, casein,
Specific examples include gelatin, water-soluble polymers such as water-soluble polyester, and carboxymethyl cellulose. Examples of dispersants include polyphosphoric acid,
Examples include polyacrylic acids.

[0058] The coating amount of the undercoat layer is 2 to 60% by dry weight.
g/m2, preferably 5 to 40 g/m2.

[0059] A method of casting immediately after applying the undercoat layer can also be carried out in the present invention. In particular, paper supports that have been cast-coated by pressing and drying the coated surface on a mirror drum heated to 50 to 110°C immediately after applying the undercoat layer improve the flatness of the support and produce high gloss. Forming a support improves the sharpness of the image, and furthermore, it is preferable because the effects of the present invention can be obtained with a smaller amount of the hydrophobic polymer applied.

The tensile strength of the paper support of the present invention is JIS
The strength specified by -P-8113 is preferably 3 to 15 kg in the longitudinal direction and 2 to 8 kg in the horizontal direction.

Furthermore, the tear strength of the paper support of the present invention is J
According to the method specified by IS-P-8116, it is preferably 20 to 100 g in the longitudinal direction and 30 to 120 g in the transverse direction. Further, the paper support of the present invention preferably has a compressive modulus of elasticity of 103 Kgf/cm2 or more.

The photothermographic paper support of the present invention preferably has a porosity defined below in the range of 15% to 50%.

The above porosity is determined by the following procedure.

[0064] Using a pycnometer according to the solid specific gravity measurement method (2.) specified in JIS-Z-8807. Therefore, the true specific gravity (D0) of the paper support is determined. On the other hand, JIS-P-811
According to 8, the weight (W) and thickness (
Measure the apparent specific gravity (D) from T). The porosity is expressed by the following formula.

[0065] Porosity (%) = 100 x [1-W/(ST, D0)] The paper support of the present invention has an internal bonding force of 0.5 to 2 Kg·cm
Base paper is preferably used. The internal bonding strength of the base paper can be adjusted to a desired value by adjusting the type and amount of pulp, filler and surface sizing agent, or the papermaking method such as the degree of beating and drying conditions.

The pH of the paper support of the present invention is preferably 4.5 to 9, particularly preferably 5 to 8. The pH of the paper support mentioned here is JIS-P-811
It was measured by the hot water extraction method described in 3.

The surface of the paper support of the photothermographic material of the present invention on which the hydrophobic polymer is coated conforms to JIS-P-8119.
Bekk smoothness specified by 50 seconds or more, preferably 1
00 seconds, more preferably 200 seconds or more, transfer unevenness is reduced when the photothermographic material is superimposed on the image-receiving material and the dye is transferred.

Furthermore, the surface of the paper support of the photothermographic material of the present invention on which the hydrophobic polymer is coated conforms to JIS-B-06.
Regarding the filtered waviness curve derived from the cross-sectional curve measured according to the No. 10 standard with a cutoff value of 0.8 mm, the maximum filtered waviness is measured with a reference length of 2.5 mm, at any 100 measurement points. and the maximum waviness is 4μm or more in 20 or less places, preferably 1
It is preferable to have a surface characteristic of 0 or less, more preferably 4 or less.

Furthermore, the surface of the paper support of the photothermographic material of the present invention on which the hydrophobic polymer is coated conforms to JIS-B-0.
Centerline average roughness R measured according to the 610 standard
a is 3 μm or less, preferably 2 μm or less, and Rma
x is 30 μm or less, preferably 20 μm or less.

Furthermore, JIS-P-8 of the surface of the paper support of the photothermographic material of the present invention on which the hydrophobic polymer is coated
The cup water absorption defined in 140 is not particularly limited, but is generally 10 g to 50 g.

The spectral reflection characteristics of the surface of the paper support of the photothermographic material of the present invention on which the polymer layer is coated are not particularly limited, and any material such as white or colored may be used. However, since the hydrophobic polymer layer is generally transparent, the reflection density is reduced to about 0 near the photosensitive wavelength of the heat-developable photosensitive material in order to improve sharpness during exposure.
．． Paper supports having three or more are particularly useful. Further, the transmission density of the paper support is preferably 0.7 or more at the exposure wavelength from the viewpoint of sharpness.

The heat-developable photosensitive material of the present invention can be used as a black-and-white or color photosensitive material, and when used as a color photosensitive material, a dye-providing substance is used.

As the dye-donating substance, for example, JP-A-61
-61157, 61-61158, 62-44
No. 738, No. 62-129850, No. 62-1298
No. 51, No. 62-129852, No. 62-16915
8 and Japanese Patent Application No. 1-200859, couplers forming diffusible dyes, such as JP-A-61-88
Leuco dye described in No. 254, U.S. Pat. No. 4,235,95
Azo dye described in No. 7 or U.S. Pat. No. 4,463,07
No. 9, No. 4,439,513, JP-A-59-6043
No. 4, No. 59-65839, No. 59-71046,
No. 59-87450, No. 59-123837, No. 5
No. 9-124329, No. 59-165054, No. 59
-165055 etc. are mentioned. Particularly preferred are compounds that form a diffusible dye through a coupling reaction, such as those represented by the general formula (a) on the second line of the lower left column on page 9 of JP-A-2-863.

Among these, preferred are polymer couplers having a polymer chain having a repeating unit derived from a monomer represented by the general formula (b) described in the eighth line of the lower right column on page 9 of the same publication.

Examples of positive dye-donating substances include:
JP-A-59-55430, JP-A No. 59-165054,
No. 59-154445, No. 59-116655, No. 59-124327, No. 59-152440, No. 6
There are compounds described in various publications such as No. 4-13546.

The above dye-providing substances may be used alone or in combination of two or more.

[0077] Further, the heat-developable photosensitive material of the present invention includes, for example,
A dye-providing substance is contained in microcapsules together with the polymerizable compounds described in JP-A No. 2-293753 and JP-A No. 2-308162, and the polymerization reaction of the polymerizable compound is imaged by heat-developing the microcapsules. Alternatively, it can be applied to a heat-developable photosensitive material in which an image is formed by raising the microcapsules in a reverse image manner and changing the diffusibility of the dye-providing substance into the image-receiving layer.

As the photosensitive silver halide used in the heat-developable photosensitive material of the present invention, conventionally known silver halides can be used, such as silver chloride, silver bromide, silver iodobromide, and silver chlorobromide. , silver chloroiodobromide can be used.

The silver halide may have a uniform composition from the inside of the grain to the surface, or may have a composition that changes continuously or stepwise between the inside and the surface.

The shape of the silver halide may be tabular, cubic, spherical, octahedral, dodecahedral, tetradecahedral, etc., or may have a distinct crystal habit.

[0081] Also, for example, US Pat. No. 2,592,250
No. 3,220,613, No. 3,271,257, No. 3,317,322, No. 3,511,622,
No. 3,531,291, No. 3,447,927, No. 3,761,266, No. 3,703,584, No. 3
, 736,140, 3,761,276, and JP-A-52-15661, JP-A-55-127549, and the like can also be used.

[0082] Metal ion species such as iridium, gold, rhodium, iron, lead, etc. can be added to the photosensitive silver halide in the form of a suitable salt during its grain formation stage.

The grain size of the photosensitive silver halide emulsion is approximately 0.
．． 02-2 μm, preferably about 0.05-0.5
It is μm.

In the present invention, as a method for preparing photosensitive silver halide, a photosensitive silver salt forming component such as a water-soluble halide is allowed to coexist with an organic silver salt described below, and a part of the organic silver salt is converted into photosensitive silver halide. It can also be formed by converting a part of silver.

The photosensitive silver halide emulsion contains a known sensitizer (
For example, the surface of silver halide grains can be chemically sensitized with activated gelatin, inorganic sulfur, sodium thiosulfate, thiourea dioxide, sodium chloraurate, etc.), and the surface of silver halide grains can be chemically sensitized with nitrogen-containing heterocyclic compounds or mercapto group-containing heterocyclic compounds. Chemical sensitization can also be carried out in the presence of.

Furthermore, the photosensitive silver halide can be spectral sensitized to blue, green, red, and near-infrared light using known spectral sensitizing dyes such as cyanine and merocyanine that are commonly used in photography.

These sensitizing dyes are used in an amount of 1 μmol to 1 mol, preferably 10 μmol, per 1 mol of silver halide.
~0.1 mol can be added at the time of forming silver halide grains, at the time of removing soluble salts, before the start of chemical sensitization, at the time of chemical sensitization, or after the end of chemical sensitization.

Known organic silver salts can be used in the heat-developable photosensitive material of the present invention for the purpose of increasing sensitivity and improving developability.

Organic silver salts that can be used in the present invention are:
For example, Japanese Patent Publication No. 43-4921, Japanese Patent Publication No. 49-526
No. 26, No. 52-141222, No. 53-36224
No. 53-37626, No. 53-36224, No. 53-37610, and U.S. Patent No. 3,33
No. 0,633, No. 3,794,496, No. 4,105
Silver salts of long-chain aliphatic carboxylic acids and silver salts of carboxylic acids having heterocycles (e.g., silver behenate, α-(1-phenyltetrazolethio)silver acetate, etc.) described in publications such as No. 451, etc. , Special Publication No. 44-26582, No. 45-1
No. 2700, No. 45-18416, No. 45-2281
No. 5, JP-A-52-137321, JP-A No. 58-1186
No. 38, No. 58-118639, U.S. Patent No. 4,123
Examples include silver salts of compounds having imino groups as described in publications such as No. 274, and acetylene silver as described in JP-A-61-249044.

Silver salts of compounds having an imino group are particularly preferred, and silver salts of benzotriazole and its derivatives (eg, silver benzotriazole, silver 5-methylbenzotriazole, etc.) are particularly preferred.

[0091] The above organic silver salts can be used alone or in combination of two or more, and these are prepared in an aqueous solution of a hydrophilic colloid such as gelatin, and used as they are after removing soluble salts. Alternatively, the organic silver salt can be isolated, mechanically pulverized and dispersed into solid fine particles, and used.

The reducing agent used in the photothermographic material of the present invention is selected from those conventionally known for use in photothermographic materials depending on the development mechanism and dye formation or release mechanism. The reducing agent mentioned here also includes a reducing agent precursor that releases a reducing agent during thermal development.

[0093] Examples of reducing agents that can be used in the present invention include those disclosed in US Pat. No. 3,351,286;
No. 761,270, No. 3,764,328, No. 3,3
No. 42,599, Specification No. 3,719,492, Research Disclosure No. 12,146, No. 15,1
No. 08, No. 15,127, and JP-A-56-2713
p-phenylenediamine-based and p-aminophenol-based developing agents, phosphoric acid amide phenol-based developing agents, sulfonamide aniline-based developing agents, and hydrazone-based developing agents described in No. 2, No. 53-135628, and No. 57-79035. Developing agents, phenols, sulfonamide phenols, polyhydroxybenzenes, naphthols,
Examples include hydroxybisnaphthyls, methylenebisphenols, ascorbic acids, 1-aryl-3-pyrazolidones, hydrazones, and precursors of the various reducing agents mentioned above.

[0094] Furthermore, the dye-donating substance can also serve as a reducing agent.

[0095] A particularly preferred reducing agent is disclosed in Japanese Patent Application Laid-Open No. 56-14
6133 and 62-227141
-N',N'-dialkylamino) phenylsulfamate and its derivatives, specifically, JP-A-2-
Compounds described in Publication No. 863, page 7, lower left column, line 6 to page 8, lower right column, can be mentioned.

A thermal solvent can be used in the heat-developable photosensitive material of the present invention for the purpose of promoting dye transfer and other purposes. The thermal solvent is a compound that liquefies during thermal development and has the effect of promoting thermal development and thermal transfer of the dye, and is preferably in a solid state at room temperature.

Examples of the heat solvent that can be used in the present invention include those described in US Pat. No. 3,347,675 and US Pat.
No. 7,959, No. 3,438,776, No. 3,666
, No. 477, Research Disclosure No. 17,
No. 643, JP-A-51-19525, JP-A No. 53-248
No. 29, No. 53-60223, No. 58-118640
No. 58-198038, No. 59-229556, No. 59-68730, No. 59-84236, No. 6
No. 0-191251, No. 60-232547, No. 60
-14241, 61-52643, 62-78
No. 554, No. 62-42153, No. 62-44737
No. 63-53548, No. 63-161446,
JP-A No. 1-224751, JP-A No. 2-863, JP-A No. 2-1
Examples include compounds described in publications such as No. 20739 and No. 2-123354. Specifically, urea derivatives (
urea, dimethylurea, phenylurea, etc.), amide derivatives (e.g., acetamide, stearylamide, p-toluamide, p-propanoyloxyethoxybenzamide, etc.), sulfonamide derivatives (e.g., p-toluenesulfonamide, etc.), polyhydric alcohols (eg, 1,6 hexanediol, pentaerythritol, polyethylene glycol, etc.) are preferably used.

The above thermal solvent can be added to any layer such as a photosensitive silver halide emulsion layer, an intermediate layer, a protective layer, or an image receiving layer of an image receiving material, and the amount added is usually 10% to the binder. The amount is preferably from 20% to 200% by weight, more preferably from 20% to 200% by weight.

[0099] Examples of the binder used in the heat-developable photosensitive material of the present invention include those described in JP-A-2-863-10.
The binders described in the 14th line of the upper right column to the 10th line of the lower left column of the page can be used, including preferred combinations. Particularly preferred binders are gelatin, polyvinylpyrrolidone, and combinations thereof.

[0100] In addition to the above, various additives may be added to the photothermographic material of the present invention, if necessary.

[0101] As the development accelerator, for example, JP-A-59-
No. 177550, No. 59-111636, No. 59-1
No. 24333, No. 61-72233, No. 61-236
No. 548, JP-A-1-152454, JP-A-61-1
No. 59642, Japanese Patent Application Publication No. 104645, Japanese Patent Application No. 1996-
The development accelerator-releasing compound described in JP-A No. 110767 or the metal ion having an electronegativity of 4 or more described in JP-A-1-104645 can also be used.

[0102] As the antifoggant, for example, US Pat.
, 645,739, mercuric salts as described in Japanese Patent Publication No. 11113/1982, N-halides as described in Japanese Patent Application Publication No. 47419/1983, and U.S. Pat. No. 3,700,457. No., Japanese Patent Publication No. 51-50725,
Compounds capable of releasing mercapto compounds described in Japanese Patent Application Nos. 1-69994 and 1-104271, JP-A-49-125
Arylsulfonic acid described in No. 016, No. 51-474
Carboxylic acid lithium salt described in No. 19, British Patent No. 1,45
5,271 and JP-A-50-101019; sulfinic acids and thiosulfonic acids as described in JP-A No. 53-19825; thiouracils as described in JP-A No. 51-3223; sulfur as described in JP-A No. 51-26019; 51-4
No. 2529, No. 51-81124, and No. 55-93
Disulfides and polysulfides described in No. 149,
Rosin or diterpenes described in No. 51-57435,
Polymer acid having carboxyl group or sulfonic acid group described in US Pat. No. 51-104338, US Pat. No. 4,138,2
Thiazolithione described in No. 65, JP-A-54-51821
No. 55-142,331, U.S. Patent No. 4,137,
Triazoles described in No. 079, JP-A-55-1408
Thiosulfinic acid esters described in No. 83, JP-A-59
-46641, 59-57233, 59-57
Di- or tri-halides described in No. 234, JP-A No. 1973
Thiol compound described in No. 9-111636, No. 60-1
Hydroquinone derivatives described in JP-A No. 98540 and JP-A No. 60-227255, antifoggants having a hydrophilic group described in JP-A-62-78554, JP-A-62-12145
Polymer antifoggant described in No. 2, JP-A-62-123
Examples thereof include an antifoggant having a ballast group described in No. 456, and a colorless coupler described in JP-A No. 1-161239.

Examples of base precursors include JP-A No. 56-130745, JP-A No. 59-157637, JP-A No. 59-166943, JP-A No. 59-180537, and JP-A No. 59-180537.
No. 9-174830, No. 59-195237, No. 62
-108249, 62-174745, 62-
No. 187847, No. 63-97942, No. 63-96
Examples include compound or base release techniques described in publications such as No. 159 and JP-A-1-68746.

Various known photographic additives other than those mentioned above can be used in the heat-developable photosensitive material of the present invention, such as antihalation dyes, antiirradiation dyes, colloidal silver, optical brighteners, It can contain hardeners, antistatic agents, surfactants, inorganic and organic matting agents, anti-fading agents, ultraviolet absorbers, anti-mold agents, white color tone adjusting agents, and the like. Regarding these, for example, RD (Research)
Disc Roger) Magazine No. No. 17029, same No. 2
No. 9963, JP-A-62-135825, and JP-A-62-135825
It is described in each publication of No.-13546.

These various additives can be appropriately added not only to the photosensitive layer but also to any constituent layers such as an intermediate layer, undercoat layer, protective layer or backing layer.

The photothermographic material of the present invention preferably contains (a) a photosensitive silver halide emulsion, (b) a reducing agent, and (c) a binder, and further contains (d) organic silver. In the case of a color photosensitive material, it further contains (e) a dye-providing substance. These may be contained in a single photographic constituent layer, or may be added separately to two or more layers.

Further, the photosensitive layer having substantially the same color sensitivity may be composed of two or more photosensitive layers, each of which may be a low-sensitivity layer and a high-sensitivity layer.

When the heat-developable photosensitive material of the present invention is used as a full-color recording material, it usually has three photosensitive layers with different color sensitivities, and dyes with different hues are formed in each photosensitive layer by heat development. or released. In this case, generally the blue-sensitive layer (B) contains a yellow dye (Y),
A magenta dye (M) is combined in the green photosensitive layer (G), and a cyan dye (C) is combined in the red photosensitive layer (R), but the present invention is not limited to this, and any combination is possible. be. Specifically, (B-C)-(G-M)-(R
-Y), (infrared sensitive -C) -(G-Y)-(RM)
Combinations such as the following are also possible.

The layer structure of each layer is arbitrary, and in order from the support side, R-G-B, G-R-B, R-G-infrared, G-R
- Infrared, etc. layer arrangements are possible.

In addition to the photosensitive layer, the heat-developable photosensitive material of the present invention may optionally include non-photosensitive layers such as an undercoat layer, an intermediate layer, a protective layer, a filter layer, a backing layer, and a release layer. .

When the photothermographic material of the present invention is of a transfer type, an image-receiving material is preferably used. The image receiving material is
It is composed of a support and an image-receiving layer having a dye-receiving ability provided thereon, but the support itself can also serve as an image-receiving layer having a dye-receiving ability.

The image-receiving layer can be broadly divided into cases where the binder constituting the layer itself has a dye-receiving ability, and cases where the binder contains a mordant capable of receiving the dye. When the binder has dye-accepting ability, the substance preferably used has a glass transition temperature of about 40°C or higher, about 2
It is preferable to use a polymer with a temperature of 50°C or less.
Edition” (Joy Brandrup, E.
Edited by H. Inmargut), John Willie
& Sons Publishing {Polymer Handbo
ok 2nd. ed. (J.Brandrup,
E. H. Edited by Immergut) John Wily &amp;
The glass transition temperature listed in
Synthetic polymers having a molecular weight of 2,000 to 200,000 are generally useful. These polymers may be used alone or in combination of two or more types, and may be copolymerizable polymers having two or more types of repeating units.

Specifically, the polymers described in JP-A-2-863, page 14, line 14 of the upper left column to line 14 of the upper right column can be used, including preferred polymers.

In an image-receiving material in which the image-receiving layer contains a mordant in the binder, a polymer containing a tertiary amine or a quaternary ammonium salt is preferably used as the mordant; for example, as described in US Pat. No. 3,709,690, as well as,
Examples include compounds described in JP-A-64-13546 and the like. Furthermore, as the binder used to hold these mordants, for example, hydrophilic binders such as gelatin and polyvinyl alcohol are preferably used.

A dye-receiving layer formed by dispersing a hydrophobic polymer latex having dye-receiving ability in a hydrophilic binder can also be used in the present invention, similar to the image-receiving layer having a mordant in the binder.

The image-receiving material of the present invention may be provided with a single image-receiving layer on a support, or may be provided with a plurality of constituent layers, in which case all of them may contain dyes. It may be an image-receiving layer, or only a part of the constituent layers may be an image-receiving layer.

When the image-receiving material has a support separate from the image-receiving layer, the support of the image-receiving material may be either a transparent support or a reflective support, as described in JP-A-2-863-1.
It is possible to select and use the supports described from line 15 in the lower left column to line 8 in the lower right column on page 4, reflective supports having type 2 diffuse reflection, and the like.

Various known additives can be added to the image receiving member of the present invention. Such additives include, for example, stain inhibitors, ultraviolet absorbers, optical brighteners, image stabilizers, development accelerators, antifoggants, pH regulators (acids and acid precursors, base precursors, etc.), thermal Examples include solvents, organic fluorine compounds, oil droplets, surfactants, hardeners, matting agents, and various metal ions.

The heat-developable photosensitive material of the present invention can be exposed by any known exposure means suitable for the color sensitivity of the photosensitive material.

[0120] As the exposure light source that can be used, those described in JP-A-2-863, page 12, lower left column, lines 13 to 16, can be used, and preferably a laser light source, a CRT light source, or an LED. used. Furthermore, a light source that combines a semiconductor laser and an SHG element (second harmonic generation element) can also be used.

[0121] Regarding the exposure time, whether one screen is exposed once or
Or, it depends on whether the exposure is done digitally for each pixel.
In the former case, the period is usually 0.001 seconds to 10 seconds, and in the latter case, the period is 10-8 to 10-2 seconds per pixel.

[0122] During exposure, a color filter may be used to adjust the color temperature of the exposure light source, if necessary, or scanner exposure may be performed using a laser or the like.

The heat-developable photosensitive material of the present invention is prepared at a temperature of preferably 70 to 200°C, more preferably 90 to 170°C, preferably 1 to 180 seconds, and even more preferably 2 to 200°C, after or simultaneously with imagewise exposure. Heat development is performed for 120 seconds to form a dye image. Transfer of the diffusible dye to the image-receiving material may be carried out simultaneously with heat development by bringing the image-receiving layer surface of the image-receiving material into close contact with the photosensitive layer side of the photosensitive material, or transfer the image-receiving material to the photosensitive material after heat development. The dye may be transferred by bringing the photosensitive material into close contact with the material, or the photosensitive material and the image-receiving material may be brought into close contact after water is supplied. Also, before exposure, 70-16
Preheating photosensitive materials in the range of 0°C,
As described in No. 143338 and No. 61-162041, at least one of the light-sensitive material and the image-receiving material can be preheated at a temperature in the range of 80 to 120 DEG C. immediately before development.

[0124] When thermally developing the photothermographic material of the present invention, known heating means can be applied. The method described above, a method using far-infrared heating, and the like can be used.

[0125] There are no particular restrictions on the heating pattern during thermal development, such as a method in which development is carried out at a constant temperature, a method in which the initial stage of development is carried out in a high temperature state and a method in which the latter half of development is carried out in a low temperature state, or the reverse method.
Furthermore, any method such as a method of changing the temperature range in three or more steps or a method of continuously changing the temperature can be used.

[0126]

[Examples] Specific examples of the present invention will be described below. However, it goes without saying that the present invention is not limited to the following examples.

Example 1 (1) Preparation of photosensitive material A subbing layer shown in Table 1 was coated on a 150 μm thick polyethylene terephthalate support having a backing layer on the back surface by solvent coating or hot melt coating.

Subbing binder (B-1) Vinyl chloride/vinyl alcohol/methacrylate/glycidyl methacrylate copolymer resin (Tg50°C) Subbing binder (B-2) Butyl acrylate/hydroxyethyl methacrylate/styrene copolymer resin (Tg54 ℃) Undercoat binder (B-3) Butyl acrylate/glycidyl methacrylate/styrene copolymer resin (Tg 0℃) The surface of the undercoat layer was subjected to corona discharge treatment at an intensity of 30 W/(m2・min), and then the following treatment was performed. The heat-developable photosensitive material No. 1 of the present invention, which has a photosensitive layer and is shown in Table 1, has a photosensitive layer. 1 to 29 and comparative sample No. 1 to 6 were created.

The amount of each additive used in each layer is the amount per 1 m 2 of the photothermographic material.

Preparation of green-sensitive silver iodobromide emulsion (Em-1) Average grain size 0.17 μm (grain size distribution 9%), silver iodide composition 2
Potassium iridium (IV) hexachloride was added at the time of grain formation, and the shape was approximately cubic with slightly rounded corners and sides. Sodium thiosulfate, sodium chloroaurate, and the following mercapto compound - 3 mg per silver mole were added and chemically sensitized to the optimum point in the presence of the following sensitizing dye (a), and at the end of the chemical sensitization, 4- Hydroxy-6-methyl-1,3,3a
, 7-tetrazaindene per mole of silver halide
g was added.

[0131]

[Case 2]

Preparation of green-sensitive layer Green-sensitive silver iodobromide emulsion (Em-1) 0.21 g, benztriazole silver 0.12 g, gelatin 0.79 g, reducing agent-1 0.24 g, dye-providing substance - 1 0.8g, anti-irradiation dye-1 0.04g, heat solvent-1
1.0g, PVP 0.07g, NaBr 0.00
12g, benztriazole 0.0018g, antifoggant-1 0.02g, color stain inhibitor-W-1 0.0
8g, DOP 0.3g, DAP-1 0.02g, hardener-1 0.03g per 1g of gelatin

[0133]

[Chemical formula 3]

[0134]

[C4]

[0135]

[C5]

Preparation of benzotriazole silver emulsion An ammoniacal silver nitrate aqueous solution and benzotriazole (contains 0.2 mol of ammonia water relative to benzotriazole) in a 10% aqueous phenylcarbamoyl gelatin solution at 50°C.
After addition, the pH of the solution is lowered, and the solution is agglomerated and desalted to form needle-like crystals (width 0.1-0.2 μm).
, length 0.5-2 μm).

Preparation of dye image-receiving material A dye image-receiving layer having the following composition was provided on photographic baryta paper to obtain image-receiving material-1.

The composition of the image-receiving layer is as follows.

[0139] Polyvinyl chloride

10g Image stabilizer-1

0.7g Image stabilizer-2

0.5g Image stabilizer-3

0.3g Image stabilizer-4

1.0g Image enhancer-1

0.7 g The image-receiving layer was applied by extrusion coating using a coating solution having the above composition (solvent: methyl ethyl ketone).

[0140]

[C6]

Evaluation of Photographic Performance The obtained light-sensitive material was subjected to step wedge exposure and subjected to the following treatment-1.

Processing-1 (simultaneous development-transfer processing) After superimposing the photosensitive material and the image-receiving material-1,
-1 with the tram belt type heat developing material shown in 228156
After thermal development at 50° C. for 75 seconds, the photosensitive material and image-receiving material were quickly peeled off, and a magenta dye image was obtained on the image-receiving material.

Processing-2 (Development-Transfer Separation Processing) The photosensitive material was thermally developed for 60 seconds on a flat heater heated to 150°C, and then superimposed on the image-receiving material-1, followed by the above-mentioned processing- Dye transfer processing was performed at 140° C. for 10 seconds using the drum-belt type thermal developing material used in 1. When the light-sensitive material and image-receiving material were quickly peeled off, a magenta dye image was obtained on the image-receiving material.

The maximum density (reflection) of the magenta dye image obtained in Process-1 was measured using a PDA-65 densitometer manufactured by Konica Corp., and the results are shown in Table 1.

Evaluation of Absorbency of Undercoat Layer A photosensitive material (A) for evaluation was prepared in the same manner as described in Table 1 except that dye-providing substance-1 was removed from the photosensitive layer of the present invention-3 sample of the photosensitive material.

[0146] The undercoat surface of the support coated with the undercoat layer shown in Table 1 (without photosensitive layer) and the above photosensitive material for evaluation (A) were superimposed and heat treated at 150°C for 90 seconds. .

After peeling off the support coated with the subbing layer, the change in weight before and after the heat treatment was measured, and the values calculated using the following formula are shown in Table 1 as the absorption amount of the subbing layer.

Absorption amount of subbing layer = (undersubbed support [weight after treatment (g) - untreated weight (g)]) / approximate weight of transferable material [1.4 g = hot solvent + DOP + part of reducing agent + α ]×1
00 Further, the film adhesion and curling degree of each undeveloped photosensitive material were measured by the following methods and are shown in Table 1.

Film attachment property: On the surface of the photosensitive layer of the photosensitive material, which has been conditioned at 20°C and 20% RH,
Using a cutter knife, make a grid-like scratch with a side of approximately 5 mm 3
After attaching 0, apply adhesive tape (Cellotape manufactured by Nichiban)
Attach the tape and remove it vigorously using a certain amount of force.

[0150] The number of gratings in which the photosensitive layer was peeled off by this operation was counted and evaluated according to the following criteria.

[0151] Evaluation Criteria Rank Film adhesion Number of peeled grids ◎ No peeling at all
0○ Slight peeling
1~3△ Partial peeling
4~8x Peeling
11~15xx Full peeling 16 or more Curl property Cut the photosensitive material into 10cm x 10cm size at 20℃
The degree of curvature was measured using 1/R (R: radius of curvature, unit is meter) after humidity conditioning for 20 hours in each relative humidity atmosphere of 20% RH, 50% RH, and 80% RH.

[0152] Also, when the photosensitive material is placed on a horizontal table with the photosensitive layer side up, the direction of the curvature is + if the curvature is concave, and - if it is convex, and from 20% RH. The amount at which the difference in the degree of curvature becomes the largest under 80% RH conditions was defined as the degree of curl (△ curl), and evaluation was performed according to the following criteria.

[0153] Evaluation criteria rank Curl characteristics Curl degree (△ curl) ◎ Good
0~5○ Almost good
5～10△
Slightly humidity dependent 11-15×
Humidity dependent 16-30×
× 〃 Large
31 or more

[0154]

[Table 1]

[0155]

[Table 2]

As is clear from Table 1, in the samples of the present invention in which the amount of hot water permeated through the undercoat layer is 20 g or less, materials such as hot solvents are absorbed into the undercoat layer even under high temperature conditions during thermal development. It can be seen that the film is thinner and the developability (image density) is significantly improved.

[0157] Furthermore, it was confirmed that the photosensitive material of the present invention not only improved developability but also had performance equivalent to or better than that of the comparative sample in sample physical properties such as film adhesion and curling properties. .

Example 2 (1) Preparation of photosensitive material A subbing layer shown in Table 2 was coated on a 165 μm thick photographic baryta paper having a backing layer on the back side by solvent coating or hot melt coating.

Subbing Polymer B-4 The following resins were blended and coated, and then cured by ultraviolet irradiation.

Polyester acrylate 1,6-hexanediol diacrylate tripropylene glycol diacrylate benzophenone subbing polymer B-5 The following resins were blended and coated, and then cured by electron beam irradiation.

Acrylic Modified Polyurethane Neopentyl Glycol Hydroxypivalate/Caprolactone/Diacrylate Trimethylol Propane Triacrylate The surface of the subbing layer (upper layer and lower layer) shown in Table 2 was subjected to corona discharge treatment (3
0 W/m2/min), and then heat-developable photosensitive material No. 1 having the layer structure shown below was applied. 30 to 53 and comparative sample No. 7 to 12 were produced.

Preparation of infrared-sensitive silver iodobromide emulsion (Em-2) Average grain size 0.12 μm (grain size distribution 8%), silver iodide composition 2
Potassium iridium (IV) hexachloride was added at the time of grain formation, and the shape was roughly cubic with slightly rounded corners and sides. Chemical sensitization was carried out to the optimum point in the presence of sodium thiosulfate, sodium chloroaurate, the following mercapto compound (1), and the following sensitizing dye (b).

Preparation of red-sensitive silver iodobromide emulsion (Em-3) Average grain size 0.12 μm (grain size distribution 8%), silver iodide composition 2
Potassium iridium (IV) hexachloride was added at the time of grain formation, and the shape was roughly cubic with slightly rounded corners and sides. Chemical sensitization was carried out to the optimum point in the presence of sodium thiosulfate and the following sensitizing dye (c).

The two types of photosensitive silver halide emulsions described above have 4-hydroxy-6-methyl-1,3,
1 g of 3a,7-tetrazaindene was added per mole of silver halide.

[0165]

[C7]

Composition of heat-developable photosensitive layer (protective layer) 0.6 g of gelatin, 0.1 g of silica powder, 0.5 g of thermal solvent-1, 0.2 g of ultraviolet absorber-1, DO
P0.15g, zinc sulfate 0.28g, reducing agent-1 0.
2g, reducing agent-2 0.1g, PVP 0.11g, antifoggant-1 0.026g (Infrared-sensitive layer) Infrared-sensitive silver iodobromide emulsion (Em-2)
0.31g, reducing agent-1 0.3g, gelatin 0.97
g, benztriazole silver 0.43 g, dye-donating substance -
2 1.16g, PVP0.07g, heat solvent-1 1.
2g, DOP0.48g, antifoggant-1 0.04
2g, antifogging agent-2 0.01g, color stain prevention agent-
1 0.22g, benztriazole 0.009g, anti-irradiation dye-2 0.05g, DAP-1
0.02g (middle layer) Gelatin 0.67g, Heat solvent-1 0.6g, Reducing agent-1 0.35g, Reducing agent-2
0.12g, UV absorber-1 0.3g, DOP0
．． 1g (Green-sensitive layer) Green-sensitive silver iodobromide emulsion (Em-1) 0.
21g, benztriazole silver 0.12g, gelatin 0
．． 79g, reducing agent-1 0.24g, dye-donating substance-2
0.8g, anti-irradiation dye-1 0.04
g, thermal solvent-1 1.0g, PVP0.07g, NaB
r0.0012g, benztriazole 0.0018g
, Antifoggant-1 0.02g, Color stain inhibitor-W-
1 0.08g, DOP0.3g, DAP-1 0.0
2g (middle layer) gelatin 0.72g, heat solvent-1 0.8g
, reducing agent-1 0.2g, reducing agent-2 0.1g, ultraviolet absorber-1 0.3g, DOP 0.1g, antifoggant-10.03g, PVP 0.07g, zinc sulfate 0.1
9g (Red-sensitive layer) Red-sensitive silver iodobromide emulsion (Em-3) 0.
39g, benztriazole silver 0.42g, gelatin 0
．． 86g, reducing agent-1 0.28g, dye-donating substance-3
1.18g, heat solvent-1 1.6g, PVP0.06
g, anti-irradiation dye-3 0.06g, Na
Br0.0012g, benztriazole 0.0096
g, antifoggant-1 0.039g, color stain inhibitor-
1 0.1g, DOP0.3g, DAP-1 0.03
g The amount of the photosensitive silver halide emulsion in each of the above constituent layers is shown in terms of silver. Also, each constituent layer is per 1g of gelatin,
It was hardened with 0.05g of hardener-1.

[0167]

[Chemical formula 8]

[0168]

[Chemical formula 9]

Evaluation of photographic performance and film adhesion After the obtained heat-developable photosensitive material was exposed with a step wedge for exposure to infrared light, green light, and red light, it was subjected to Process-1 and Process-2 shown in Example-1.
The maximum transmission density of the obtained yellow, magenta, and cyan color images was measured in the same manner.

[0170] In addition, the absorbency of the undercoat layer, the film adhesion property, and the degree of curling were evaluated in the same manner as in Example-1.

[0171] However, the undercoat layer absorption amount was calculated using the following formula.

Absorption amount of subbing layer = subbed support [weight after treatment (g) - untreated weight (g)]/approximate weight of transferable material [8
g=thermal solvent+DOP+reducing agent+α] The results are shown in Table 2.

[0173]

[Table 3]

[0174]

[Table 4]

As is clear from Table 2, the effect of the present invention is sufficient even when a paper support is used, and a low Tg resin and/or a hydrophilic resin is used in the subbing layer near the photosensitive layer. It can be seen that the film adhesion properties and curling properties are further improved by containing the above.

Example 3 A photosensitive material was prepared in the same manner as in Example 2, except that the baryta paper support used in Example 2 was replaced with double-sided cast coated paper (both sides chrome color, manufactured by Shin-Fuji Paper Industries). and evaluated using the same method.

As a result, the same effects of the present invention as in Example-2 were obtained.

Example-4 Photosensitive materials No. 3, 4, and 8 of the present invention prepared in Example-1
, 14, 22, 24, 26 and comparative sample No. After exposing 1 and 5 in the same manner, wire bar coating was applied with the solvent shown below to a wet film thickness of 16 μm, and the flat surface was layered with the image receiving material prepared in Example 1 and heated to 140°C. It was heated on a heater for 75 seconds while applying a pressure of 4 kg/cm2.

When the light-sensitive material was peeled off, a magenta dye image was obtained on the image-receiving material, and evaluation was performed in the same manner as in Example-1.

[0180]

[Chemical formula 10]

The results are shown in Table 3.

[0182]

[Table 5]

The results in Table 3 show that even in the method of supplying the solvent during thermal development from the photosensitive material and/or from the outside, when the photosensitive material having the structure of the present invention is used, the amount of subbing absorption at high temperatures is small. It can be seen that the developability and sample physical properties are improved.

[0184]

[Effects of the Invention] According to the present invention, it is possible to provide an image forming method using a heat-developable photosensitive material that has good developability and dye transfer rate, and has improved curling and film adhesion between the photosensitive layer and the subbing layer. Ta.

Claims (9)

[Claims] [Claim 1] A heat developable material having at least one subbing layer containing a hydrophobic resin on a support, and a photosensitive layer containing a hydrophilic binder, silver halide, and a dye-providing substance thereon. After the photosensitive material is imagewise exposed, it is overlaid with a dye-receiving material to perform heat development and dye transfer at the same time, or the heat-developable photosensitive material is thermally developed and then overlaid with a dye-receiving material to transfer the dye to the dye-receiving material. In the image forming method in which the undercoat layer has a hot water permeation amount of 20 g/m2 or less, and the heat-developable light-sensitive material and the dye-receiving material are overlapped and thermally developed, or An image forming process characterized in that the process of transferring a dye to an image-receiving material is carried out in the presence of a solvent. 2. The image forming method according to claim 1, wherein the amount of hot water permeated is 10 g/m 2 or less. 3. The image forming method according to claim 1, wherein the hydrophobic resin has a Tg of 50° C. or higher. 4. The image forming method according to claim 1, wherein the hydrophobic resin has a Tg of 60° C. or higher. 5. The image forming method according to claim 1, wherein the support is a paper support. 6. The hydrophobic resin of claim 1, wherein the hydrophobic resin of the undercoat layer on a side farther from the support has a lower Tg than that of the undercoat layer on a side closer to the support. Image forming method. 7. The image forming method according to claim 1, wherein the subbing layer furthest from the support contains at least one hydrophilic resin. 8. Claim 1, wherein the amount of the hydrophobic resin used in the undercoat layer is 0.1 to 10 g/m2.
The image forming method described. 9. The image forming method according to claim 7, wherein the amount of the hydrophilic resin used in the undercoat layer is 0.01 to 10 g/m2.