JPH01222992A - Multi-color recording material - Google Patents

Abstract

PURPOSE:To obtain a multi-color image with high coloring density and little fogging, by providing an intermediate layer formed by gelling a water-soluble polyanion polymer with a polyvalent cation between respective color forming layers. CONSTITUTION:As an intermediate layer, a layer gelling particularly a water-soluble polyanion polymer with a polyvalent cation is used between a first color forming layer and a second color forming layer. As the water-soluble polyanion polymer, an alginic alkali-metallic salt is preferably used. In the forming of the intermediate layer, it is preferable that either of the aforesaid materials is incorporated in the first or second color forming layer before coating for the prevention of a rapid gelling during coating. Furthermore, a temperature or pH can be regulated. As an alternative method, one of the materials can be incorporated in the first color forming layer and the other can be in the second color forming layer is the same manner. The intermediate layer is desirably applied in the amount of 0.05-5g/m<2>, more preferably 0.1-2g/m<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multicolor recording material, and particularly to a heat-sensitive, pressure-sensitive, and/or photosensitive recording material having overlapping recording layers so as to be capable of multicolor recording.

(Prior Art) As the most common method for obtaining multicolor images, silver halide photography has been widely put into practical use because of its high sensitivity, high image quality, and rich gradation reproducibility. However, silver halide photography has the drawback that the process is complicated because it processes the image with a developer after exposure and then converts the remaining silver halide into water-soluble silver complex salts or light-stable silver salts. have.

As a method to improve these drawbacks,
No. 764, etc. describe dry silver salt photographic materials, British Patent No. 249530, U.S. Patent No. 2゜020.775,
Same No. 2,004,625, Same No. 2,217,544, Same No. 2,255,463, Same No. 2,699,394
A dye diffusion transferable photographic light-sensitive material is described in No. 1, etc., and a silver dye bleaching photographic light-sensitive material is described in U.S. Pat.

On the other hand, recording methods such as electrophotography, thermal transfer, and inkjet methods are used as recording materials that do not use silver salts, but the devices have become larger and the reliability of recording has increased. There are disadvantages such as lack of performance and time-consuming replacement of consumables.

As a non-silver salt recording material that has the mechanism of a multicolor recording material, recording materials that combine color development methods such as pressure sensitivity, heat sensitivity, and light sensitivity are disclosed in Japanese Patent Application Nos. 61-80787 and 61-282789. No. 61-303504, No. 6
No. 2-3069, No. 62-3070, No. 62-222
No. 34, No. 62-52423, No. 62-75409, etc.

Furthermore, as one of the conventional methods, for example, Japanese Patent Publication Nos. 51-19989 and 52
-11231, JP-A No. 54-88135, JP-A No. 55-
As described in No. 133991 and No. 55-133992, there is a method in which a plurality of coloring units are simply added one after another as the imprint heating energy increases, and the colors are mixed and the hue changes while becoming muddy. Other methods include, for example,
No. 17868, No. 51-5791, No. 57-1431
No. 8, No. 57-14319, JP-A-55-16168
As shown in No. 8, there is a color-erasing mechanism in which when a color-forming unit with a higher thermal response temperature develops color, a color-erasing agent acts at the same time to erase the color-forming unit that develops color at a lower temperature.

(Problems to be Solved by the Invention) As described above, in a recording material that has multiple recording layers and has a mechanism of a multicolor recording material, it is important to prevent the material in each layer from moving between the eyebrows. .

For example, in the case of a photosensitive/thermal recording material in which the first layer is a combination of a basic dye and a color developer and the second layer is a combination of a diazo compound and a coupler, the color developer contained in the first layer is A base that acts on the second layer to promote the coupling reaction in the second layer, causing the problem of fogging in the second layer over time, and is generally used as a coupling promoter in a system of a diazo compound and a coupler. A problem arises in that the sexual substance inhibits the color development reaction of the first layer, and the color density of the first layer decreases.

Accordingly, a first object of the present invention is to provide a recording material capable of obtaining multicolor images with high color density and little fog.

A second object of the present invention is to provide a multicolor recording material in which at least two recording layers, each of which develops a different hue through a color reaction, are provided on one side of a support in a layered manner, in which the material between each color development layer is The purpose is to provide an intermediate layer suitable for preventing movement between the eyebrows.

(Means for Solving the Problems) The above-mentioned aspects of the present invention are multicolor, which is formed by providing on one side of a support at least two color-forming layers that each develop different hues through a color-forming reaction. This was achieved by a multicolor recording material characterized by providing an intermediate layer made of a water-soluble polyanionic polymer gelled with polyvalent cations between each coloring layer.

Each coloring layer according to the present invention is not particularly limited, but includes (1) a coloring layer formed by a combination of a diazo compound and a coupler, (2) a coloring layer formed by a combination of a basic dye precursor and a color developer, and (3) a coloring layer formed by a combination of a basic dye precursor and a color developer. ) A coloring layer formed by a combination of an organic reducing agent, chelating agent, sulfur compound, etc. and an organic acid metal salt, (4)
A color-forming layer made of a combination of an organic base and a color-forming substance capable of developing color by reacting with the organic base is preferred.

The diazo compound in the present invention mainly means an aromatic diazo compound, and specifically means compounds such as aromatic diazonium salts, diazosulfonate compounds, and diazoamino compounds. Hereinafter, explanation will be given mainly using diazonium salt as a representative example.

A diazonium salt is a compound represented by the general formula A r Nz '' (represents an anion).

Examples of diazonium compounds preferably used in the present invention include 4-diazo-1-dimethylaminobenzene, 4
-Diazo-1-diethylaminobenzene, 4-diazo-
1-dipropylaminobenzene, 4-diazo-1-methylbenzylaminobenzene, 4-diazo-1-dibenzylaminobenzene, 4-diazo-1-ethylhydroxyethylaminobenzene, 4-diazo-1-diethylamino-3 -methoxybenzene, 4-diazo-1-dimethylamino-2-methylbenzene, 4-diazo-1-benzoylamino-2,5-jethoxybenzene, 4-diazo-1-morpholinobenzene, 4-diazo-1- Morpholino-2,5-jethoxybenzene, 4-diazo-1-morpholino-2゜5-dibutoxybenzene, 4-diazo-
1-anilinobenzene, 4-diazo-1-tolylmercapto-2,5-jethoxybenzene, 4-diazo-1
, 4-methoxybenzoylamino-2,5-jethoxybenzene, 1-diazo-4-(N,N-dioctylcarbamoyl)benzene, l-diazo-2-octadecyloxybenzene, 1-diazo-4-(4- tert-octylphenoxy)benzene, 1-diazo-4-(2,4
-di-tert-amylphenoxy)benzene, 1-diazo-2-(4-tert-octylphenoxy)benzene, 1-diazo-5-chloro-2(4tert-octylphenoxy)benzene, i-diazo-2,5- Bis-octadecyloxybenzene, 1-diazo-2,4-
Bis-octadecyloxybenzene, 1-diazo-4-
Aromatic diazonium compounds, typified by zero or more examples such as (N-octylteraroylamino)benzene, can have a wide range of photodecomposition wavelengths by changing their substituents.

A specific example of the acid anion is 07F! ,,,1COO
-(n represents 3 to 9), CmF! mlSOz
- (m represents 2 to 8), (CffiFtt-+SO
x)zCH- (f represents 1 to 18), H shell C(CH3)5BF, -1PF6-, and the like.

In particular, as the acid anion, those containing a perfluoroalkyl group or a perfluoroalkenyl group, or PF, - are preferable because they cause less increase in fog during raw storage.

Specific examples of the diazo compound (diazonium salt) include the following examples.

c4n9 oC21(5 0C2Hs The diazosulfonate compound that can be used in the present invention is a compound represented by the general formula % Formula % where RI is an alkali metal or an ammonium compound, R1, R,,R.

and R6 is hydrogen, halogen, alkyl group, or alkoxyl group, and R4 is hydrogen, halogen, alkyl group, amino group, benzoylamide group, morpholino group, trimercapto group, or pyrrolidino group.

A large number of such diazosulfonates are known and can be obtained by treating each diazonium salt with a sulfite.

Preferred compounds among these compounds include 2-methoxy, 2-phenoxy, 2-methoxy-4-phenoxy, 2,4-dimethoxy, 2-methyl-4-methoxy,
Benzene azosulfonate having a substituent such as 2,4-dimethyl, 2,4゜6-trimethyl, 4-phenyl, 4-phenoxy, 4-acetamide, etc., or 4-(N-ethyl-N-benzyl amino), 4-(N,
N-dimethylamino), 4-(N,N-diethylamino)-3-chlor, 4-pyrogeno-3-chlor, 4-morpholino-2-methoxy, 4-(4°-methoxybenzylbenzoylamino)-2, 5-dibutoxy, 4-(
It is a benzenesulfonate having a substituent such as 4'-mercapto)-2,5-dimethoxy. When using these diazosulfonate compounds, it is desirable to irradiate the diazosulfonate with light to activate the diazosulfonate before printing.

Moreover, diazoamino compounds can be mentioned as other diazo compounds that can be used in the present invention. The diazoamino compound is a compound obtained by coupling a diazonium salt with dicyandiamide, sarcosine, methyltaurine, N-ethylanthranic acid-5-sulfonic acid, monoethanolamine, jetanolamine, guanidine, or the like.

The color developer for the diazo compound used in the present invention is a coupling component that couples with the diazo compound (diazonium salt) to form a dye.

As a specific example, for example, 2-hydroxy-3-
In addition to naphthoic acid anilide, there may be mentioned those described in Japanese Patent Application No. 60-287485, including resorcinol.

Furthermore, by using two or more of these coupling components in combination, an image of any color tone can be obtained. Since the coupling reaction between these diazo compounds and the coupling component is likely to occur in a basic atmosphere, a basic substance may be added to the layer.

As the basic substance, a poorly water-soluble or water-insoluble basic substance or a substance that generates an alkali upon heating is used. Examples of these are inorganic and organic ammonium salts,
organic amines, amides, urea and thiourea and their derivatives,
Examples include nitrogen-containing compounds such as thiazoles, pyrroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidacillines, triazoles, morpholines, piperidines, amidines, formazines, and pyridines. . Specific examples of these are described, for example, in Japanese Patent Application No. 60-132990. Two or more basic substances may be used in combination.

The hue in this coloring system is mainly determined by the diazo dye produced by the reaction between the diazo compound and the coupling component. Therefore, as is known, the coloring hue can be easily changed by changing the chemical structure of the diazo compound or the chemical structure of the coupling component, and almost any coloring hue can be produced depending on the combination. For this reason, one layer may contain various diazo compounds and one type of coupling component or other additives may be incorporated in the same layer, and in this case, each unit color forming Groups are composed of different diazo compounds, common coupling components and other additives.In addition, separate coupling components may be contained in some layers, and diazo compounds and other additives may be added to the group. There is a combination in which the same material is incorporated into each layer.In this case, each unit coloring group is composed of a different coupling component and a common diazo compound and additives.In any case, each unit coloring group A group is composed of one or more diazo compounds combined to produce different color hues, one or more coupling components, and other additives.

The coupling component is 0.1 per part by weight of the diazo compound.
It is preferable to use the basic substance in an amount of 0.1 to 20 parts by weight.

The basic dye precursor as used in the present invention has the property of donating electrons or accepting protons such as acids to develop color, and although it is not particularly limited, it is usually approximately colorless. Compounds having a partial skeleton such as , radokun, lactam, sultone, spiropyran, ester, amide, etc., and whose partial skeleton is ring-opened or cleaved upon contact with a color developer are used. Specifically, crystal violet lactone, benzoylleucomethylene blue, malachite green lactone, rhodamine B lactam, 1,
2.3-)dimethyl-6'-ethyl-8'-butoxyindolinobenzospirobilane and the like.

Acidic substances such as phenol compounds, organic acids or metal salts thereof, oxybenzoic acid esters, and activated clay are used as color developers for these color formers.

Specific examples of these color developers are disclosed in Japanese Patent Application No. 1983-132, for example.
No. 990.

Add color developer to 1 part by weight of basic dye precursor at O03-8
Preferably, 0 part by weight is used.

Examples of organic reducing agents, chelating agents, and sulfur compounds that develop color by reacting with organic acid metal salts in the present invention include tannic acid, gallic acid, alkaline earth metal sulfides, sodium thiosulfate, 1,000 urea, and hexamethylenetetramine. , pyrogallol, hydroquinone, spiroindane, protocatechuic acid, thiosemicarbazides, 1,000 urea derivatives, dithiooxamides, thioacetamide, metal salts, NN-disubstituted rubeanic acid, tin compounds, Zn salts of dithiosalbamic acid, organic polyhydroxy compound, thiosulfate, phenetidine hydrochloride,
Examples include heterohydrazine derivatives, carbamate esters, aromatic polyhydric hydroxy compounds, spirobenzopyran, and the like. Examples of organic acid metal salts include ferric stearate, Ni, Co, Cu, and Pb salts of stearic acid, heavy metal salts of oxalic acid (Ag, Pb, and Hg), silver stearate, silver behenate, and stearic acid. Silver, ferric pelargonic acid, lead caproate, nickel stearate, nickel acetate, ammonium molybutate, stearic acid or N behenic acid
i or Co salts, bismuth compounds, Cu or Fe salts of stearic acid, silver oxalate or mercury salts, lead stearate, organic acid iron, water-soluble Pb or Cb salts, organic amine molybdates, organic acid metal salts, etc. can be mentioned.

In addition, the color-forming substance that can develop color with an organic base as used in the present invention includes P that causes color development or color change in alkaline conditions.
H indicators, fluorescein derivatives, phenolphthalein derivatives, substances that cause discoloration due to oxidation or reduction in a broad sense due to a change in pH value to the alkaline side,
Ninhydrin derivatives and the like are used. Typical examples are shown below.

Examples of the organic bases used in the present invention include the following general formula % [where R+, Rz, Rs, Ra, Rs are hydrogen, alkyl having 18 or less carbon atoms, cyclic alkyl, aryl, aralkyl, Represents amino, alkylamino, acylamino, carbamoylamino, amidine, cyano or heterocyclic residue, R1 is lower alkylene, phenylene, naphthylene or (wherein X is lower alkyl L/7, Sot, St
-, -S-, -0-1-NH- or - double bond)
guanidine derivatives represented by the above formula, in which the oryl group includes those having a substituent selected from lower alkyl, alkoxy, nitro, acylamino, alkylamino, and halogen.

In addition to the above-mentioned guanidine derivatives, the following general formula, [wherein Rヮ, RQ, Rs represent hydrogen, alkyl having up to 18 carbon atoms, alkyl substituted with an amino group, cycloalkyl, aralkyl, heterocyclic residue, At least two of Rヮ, Ra, and Rs are bonded at a point other than N in the general formula, and N in the general formula
Also included are compounds represented by the following formula, including cases in which the compound becomes cyclic.

Among the above-mentioned combinations of basic dye precursor and color developer, if at least one photooxidizing agent is used as the color developer, this combination can also be used as a photocoloring material - in this case. The photooxidizing agent is activated by irradiation with light and reacts with the leuco dye to produce a colored image against a background of unirradiated and therefore unchanged material.

Leuco dyes that can be easily colored by photo-oxidizing agents include those described in the specification of US Pat. No. 3,445,234, and specific examples thereof are as follows.

(a) aminotriarylmethane (b) aminoxanthine (C) aminothioxanthin (d) amino-9,10-dihydroacridine (e) aminophenothiazine (g) aminodihydrophenazine (b) aminodiphenylmethane (i) Leucomendamine (j) Aminohydrocinnamic acid (cyanoethane, leucomethine) C) Hydrazine (1) Leucoidigoid dye (E) Amino-2,3-dihydroanthraquinone (n)
Tetrahalo p,p''-biphenol(o)2-(p
-Hydroxyphenyl)-4,5-diphenylimidazole (p) Phenethylaniline Among these leuco dyes, leuco dyes (a) to (i) develop color by losing one hydrogen atom and become dyes, The leuco dyes U) to 9) lose two hydrogen atoms to form the parent dye. Among these, aminotriarylmethane is preferred. - The type of aminotriarylmethane preferable for boat fishing is one in which at least two of the aryl groups are (a) R and Rt are each hydrogen, C8 to C3
R,, R,, N in the para position to the bond to the methane carbon atom, such as a group selected from alkyl, 2-hydroxyethyl, 2-cyanoethyl, or benzyl
-substituents and others) having a group ortho to the methane carbon atom selected from lower alkyl (-C is 1 to 4), lower alkoxy (C is 1 to 4), fluorine, chlorine, or bromine a phenyl group; and the third aryl group may be the same as or different from the first two, and if different: (a) lower alkyl, lower alkoxy, chlorine, diphenylamino, cyano, nitro, hydroxy; , fluorine or bromine, alkylthio, arylthio, thioester, alkylsulfone, sulfonic acid, sulfonamide, alkylamide, arylamide, etc.; (b) naphthyl which may be substituted with amino, di-lower alkylamino, alkylamino; (C) Pyridyl which may be substituted with alkyl; (d) Quinolyl; (e) Indolinidene which may be substituted with alkyl. R and R2 are preferably hydrogen or alkyl of 1 to 4 carbon atoms, particularly preferably all three aryl groups are the same.

Preferred photooxidizing agents for coloring oxidatively colorable leuco dyes are inert until exposed to actinic radiation, such as visible light, ultraviolet light, infrared radiation, X-rays, and the like. Various photooxidants have different peak sensitivities across the spectrum depending on the structure of the compound. The particular photooxidant chosen will therefore depend on the nature of the actinic radiation. When exposed to such radiation, the photooxidizing agent produces an oxidizing agent that oxidizes the color forming agent to its colored form.

As a typical photooxidizing agent, U.S. Patent No. 3.042.5
Halogenated hydrocarbons such as carbon tetrabromide, N-promosuccinimide, and tribromomethylphenylsulfone described in No. 15 and No. 3,502,476, Photographic Society of Japan 1
Azide polymers described in the 968 Spring Research Presentation Abstracts on page 55, azide compounds such as 2-azidobenzoxazole, benzoyl azide, and 2-azidobenzimidazole described in U.S. Patent No. 3,282.693, and U.S. Patent No. 3 Compounds such as 3-ethyl-1-methoxy-2-pyridothiacyanine verchlorate and l-methoxy-2-methylpyridinium-p-)luenesulfonate described in No. 615,568, Japanese Patent Publication No. 62-39,728 2.4. At least one selected from the group consisting of lophine dimer compounds such as the 5-triarylimidazole dimer, compounds such as pentuphenone, p-aminophenyl ketone, polynuclear quinone, thioxanthenon, and mixtures of the above compounds. Includes, but is not limited to, one type of photooxidative subcompound.

The first coloring layer and the second coloring layer may be a combination of the above-mentioned different coloring reactions (or may be a combination of the same coloring reactions with different coloring hues).

Further, the energy for causing the first coloring layer and the second coloring layer to undergo a coloring reaction may be any energy such as thermal energy, pressure, light energy, electrical energy, etc. (or may be energy from a combination of these).

Materials that produce the above color reaction are selected from the viewpoint of improving transparency, preserving stability (fogging prevention) by preventing contact between the color forming agent and the color developer at room temperature, and color development that develops with the desired applied energy. A part of the components can also be microencapsulated and used from the viewpoint of sensitivity control.

The wall materials of the microcapsules mentioned above include polyurethane, polyurea, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene-methacrylate copolymer, styrene-acrylate copolymer, gelatin, polyvinylpyrrolidone,
Examples include polyvinyl alcohol. In the present invention, two or more of these polymeric substances can also be used in combination.

In the present invention, among the above-mentioned polymeric substances, polyurethane, polyurea, polyamide, polyester, polycarbonate, etc. are preferable, and polyurethane and polyurea are particularly preferable.

The microcapsules used in the present invention are preferably microencapsulated by emulsifying a core material containing a reactive substance such as a coloring agent, and then forming a wall of a polymer material around the oil droplets. In this case, a polymeric material is formed or an actant is added to the interior of the oil droplet and/or to the exterior of the oil droplet. Details of microcapsules that can be preferably used in the present invention, such as preferred methods for producing microcapsules, are described in, for example, JP-A-60-242094.

Here, the organic solvent for forming oil droplets can generally be appropriately selected from high boiling point oils, but
In particular, when an organic solvent suitable for dissolving the color developer is used, it has excellent solubility in the color former, increases the color density and speed of color development during thermal printing, and also reduces fog (
This is preferable because it can be done.

When making microcapsules, they can be made from an emulsion containing 0.2% by weight or more of the component to be microencapsulated.

In the present invention, the size of the microcapsules is preferably a volume average particle size of 10 μm or less, particularly preferably 2 μm or less, as determined by the measurement method described in JP-A No. 60-214990.

In the present invention, it is also possible to use a color development aid.

When thermal energy is used as the applied energy, the color development aid that can be used in the present invention is a substance that increases the color density during heated printing or lowers the minimum color development temperature, and includes coupling components, basic A situation in which diazo, basic substances, coupling components, color formers, and color developers are likely to react due to the effect of lowering the melting point of the substance, color former, color developer, or diazo compound layer, or lowering the softening point of the capsule wall. It is for making.

Coloring aids include phenolic compounds, alcoholic compounds, amide compounds, sulfonamide compounds, etc.
Specific examples include pt:ert-octylphenol, p-benzyloxyphenol, phenyl p-oxybenzoate, benzyl carbanylate, phenethyl carbanylate, hydroquinone dihydroxyethyl ether,
Compounds such as xylylene diol, N-hydroxyethyl-methanesulfonic acid amide, and N-phenyl-methanesulfonic acid amide can be mentioned. These may be contained in the core material or may be added outside the microcapsules as an emulsified dispersion.

The color-forming material of the present invention can be coated using a suitable binder.

Binders include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinylpyrrolidone, casein, styrene-butadiene latex, acrylonitrile-butadiene latex, polyvinyl acetate, polyacrylic acid ester, ethylene-vinyl acetate, etc. Various emulsions such as polymers can be used. The amount used is 0.5 to 5 g/m'' in terms of solid content.

In the present invention, it is essential to provide an intermediate layer between the first coloring layer and the second coloring layer, but in the present invention, this intermediate layer is made of a water-soluble polyanionic polymer gelled with polyvalent cations. Use layers.

Preferred water-soluble polyanionic polymers are polymers having carboxyl groups, sulfonic acid groups, and phosphoric acid groups, and particularly preferred are water-soluble polyanionic polymers having carboxyl groups. Examples of preferred water-soluble polyanionic polymers include ~ natural or synthetic polysaccharide gums (
Examples include alginate alkali metal salts, guar gum,
gum arabic, carrageenan, pectin, gum tragacanth, xanthine gum, etc.), polymers of acrylic acid or methacrylic acid and their copolymers, polymers of maleic acid or phthalic acid and their copolymers, cellulose derivatives such as carboxymethylcellulose, gelatin , agar, etc., among which alginate alkali metal salts are preferred, the water-soluble polyanionic polymer has a molecular weight of 5.000 to 10,
00 (l better), especially from the viewpoint of barrier properties and manufacturing suitability aimed at in the present invention, from 10,000 to 40,0
00 is preferred, and polyvalent cations include salts of alkaline earth metals and other valent metals (e.g. CaC/!, Ba
C1z, Al1z(Son)s, ZnSO4, etc.)
, polyamines (eg, ethylenediamine, diethylenetriamine, hexamethylenediamine, etc.), and polyimines are preferred.

Another preferred example of the intermediate layer in the present invention is ionic conchelex, which is a water-soluble polyanionic polymer and a water-soluble polycationic polymer. In this case, the various water-soluble polyanionic polymers described above can be used as the water-soluble polyanionic polymer.

Preferred water-soluble polycationic polymers include proteins having a plurality of reactive nitrogen-containing cationic groups, polypeptides such as polylysine, polyvinylamines, polyethyleneamines, polyethyleneimines, and the like.

When preparing an intermediate layer using these materials, it is preferable to include one of the materials in the first coloring layer or the second coloring layer to prevent rapid gelation during coating. However, it is also possible to further adjust the temperature and pH, or to include one material in the first coloring layer and the other material in the second coloring layer.

The preferred coating amount of the intermediate layer is 0.05 g/m” to 5 g/m
”, more preferably 0.1 g/m2 to 2 g/m
” is.

In the present invention, a white pigment may be added to the coloring layer or intermediate layer for the purpose of preventing fog or increasing whiteness, or a layer containing a white pigment may be additionally coated.

Examples of preferred white pigments include talc, calcium carbonate, calcium sulfate, magnesium carbonate, magnesium hydroxide, alumina, synthetic silica, titanium oxide, barium sulfate, kaolin, calcium silicate, urea resin, and the like.

Furthermore, it is also possible to provide a protective layer on the top layer.

The protective layer is made of a water-soluble polymer such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, etc., to which pigments, metal soaps, waxes, crosslinking agents, etc. are added.

Pigments include zinc oxide, calcium carbonate, barium sulfate, titanium oxide, lithopone, talc, Rouseki, kaolin, aluminum hydroxide, amorphous silica, etc., and the amount added is 0.05 to 2.0% of the total weight of the polymer. times, particularly preferably 0
．． It is 1 to 5 times the amount.

Metal soaps include emulsions of higher fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate, etc., and the proportion of the soap is 0.5 to 20% by weight, preferably 1 to 10% by weight of the total weight of the first layer. added in quantity. Waxes include emulsions such as paraffin wax, microcrystalline wax, carnauba wax, methylol stearamide, polyethylene wax, silicone, etc., and their content is 0.5 to 40% by weight of the total weight of the protective layer.
It is preferably added in a proportion of 1 to 20% by weight.

In addition, a surfactant, a polymer electrolyte, etc. may be added to the protective layer to prevent charging of the heat-sensitive recording material.The solid content coating amount of the protective layer is usually 0.2 to 5 g/rrl. is preferable, and more preferably Ig to 3 g/rrf.

For more information about the protective layer, see Paper and Pulp Technology Times N
o, 8 (1985).

Furthermore, an undercoat layer may be provided for the purpose of increasing the adhesion between the support and the coloring layer, improving smoothness, and providing heat insulation.

As the material for the undercoat layer, water-soluble polymers such as gelatin, synthetic polymer latex, nitrocellulose, etc. are used. The coating amount of the undercoat layer is 0. 1g/ryf~2. Og/r
It is preferably in the range of d, especially 0.2g10f~
A range of 1.0 g/i is preferable.

Examples of the support used in the present invention include paper, synthetic paper, and polymer film.

In the present invention, the paper used for the support is a neutral paper with a heat extraction pH of 6 to 9 sized with a neutral sizing agent such as an alkyl ketene dimer (Japanese Patent Laid-Open No. 55-1428
The use of the product described in No. 1) is advantageous in terms of storage stability over time.

In order to prevent the coating liquid from penetrating into paper,
The paper described in No. 687 and having a Bekk smoothness of 90 seconds or more is advantageous.

In addition, the optical surface roughness described in JP-A-58-136492 is 8μ or less and the thickness is 40 to 75μ, JP-A-58-136492.
Paper with a density of 0°9 g/cn or less and an optical contact ratio of 15% or more as described in No. 8-69097, JP-A-58-6909
Canadian standard freeness described in No. 7 (JIS P8121
) paper made from pulp beaten to 400 cc or more to prevent penetration of coating liquid, JP-A-58-65695
JP-A-59-35985 describes a method in which the glossy side of a base paper made by a Yankee machine is used as the coated surface to improve color density and resolution, and a method in which the base paper is subjected to corona discharge treatment as described in JP-A-59-35985. Papers with improved coating suitability may also be used in the present invention with good results. In addition to these, any support commonly used in the field of heat-sensitive recording paper can be used as the support of the present invention.

In the present invention, a back layer may be provided on the back surface of the support for the purpose of curl correction, antistatic properties, and improved slipperiness. As the constituent components of the back layer, it is preferable to use the same components as those of the protective layer.

Among the supports used in the present invention, polymer films include polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate films, polystyrene films, polypropylene films, and polyolefin films such as polyethylene. , these can be used alone or in combination.

The thickness of the support used is 20 to 200 .mu.m, particularly preferably 50 to 100 .mu.m.

The coating liquid according to the present invention can be applied by generally (known coating methods,
For example, dip coating method, air knife coating method, curtain coating method, roller coating method, doctor coating method,
Coating can be performed by a wire barcode method, a slide coating method, a gravure coating method, or an extrusion coating method using a hopper as described in US Pat. No. 2,681,294. U.S. Patent Nos. 2,761,791 and 3,508,947, as appropriate.
No. 2,941,898, and No. 3゜526.
Specification No. 528, Yuji Harasaki, "Coating Engineering" 25
It is also possible to apply the product simultaneously in two or more layers using the method described on page 3 (published by Asakura Shoten in 1973), and an appropriate method can be selected depending on the amount of application, application speed, etc. .

The coating liquid used in the present invention includes a pigment dispersant and a thickener.

There is no problem in adding flow modifiers, antifoaming agents, foam inhibitors, mold release agents, coloring agents, surfactants, etc., as necessary, as long as they do not impair the properties.

When carrying out the present invention, the number of coloring layers is not limited to two, and a plurality of layers can be further provided thereon. In this case, coloring layers with different coloring hues are usually provided.

Even when multiple coloring layers are provided, at least one intermediate layer as disclosed in the present invention is provided.

It is also possible to provide coloring layers on both sides of the support.

When the support is transparent, such an embodiment is preferably utilized.

(Example) The present invention will be further explained below with reference to Examples, but the present invention is not limited thereto.

Note that "parts" indicating the amount added represent "parts by weight."

Example 1 Diazo compound 3.4 parts Tricresyl phosphate 6 parts Methylene chloride
12 parts trimethylolpropane trimethacrylate 18 parts D-11ON (75% by weight ethyl acetate solution) (manufactured by Takeda Pharmaceutical Co., Ltd. (trade name)) 24 parts were mixed, and 8 parts by weight of polyvinyl alcohol (Kuraray PVA-217E) were mixed. %
After adding it to an aqueous solution consisting of 63 parts of aqueous solution and 100 parts of distilled water, it was emulsified and dispersed at 20°C to obtain an emulsion with an average particle size of 2μ, and the resulting emulsion was continuously stirred at 40°C for 3 hours. Ta.

After cooling this liquid to 20°C, Amberlite IR-
120B (manufactured by Rohm and Haas (product name))
After adding 0 cc and stirring for 1 hour, it was filtered to obtain a capsule liquid.

Coupler voice SA's tLIJ ■, polyvinyl alcohol (Clari PVA205) 4% by weight aqueous solution 170 parts ■, coupler
14 parts 11゜ U U Triphenylguanidine (base) 6 parts Color development aid mixed, Dynomil (Willy A. Bacofen,
Dispersed with A.G. Co., Ltd. (trade name) to achieve an average particle size of 3.
A dispersion of μ was obtained.

Feeling 'A' 1 2-anilino-3-methyl-N-methyl- as a coloring agent
20 g each of N-cyclohexylaminofluorane, bisphenol A as a color developer, and β-naphthylbenzyl ether as a sensitizer were dispersed with 100 g of a 5% polyvinyl alcohol (Clary PVA-105) aqueous solution in a ball mill day and night. The average particle size was set to 3 μm or less. As a pigment, calcium carbonate (Unibur70
Each dispersion prepared as described above was used by dispersing 80 g of 0.5% sodium hexametaphosphate solution with 160 g of a 0.5% sodium hexametaphosphate solution using a homogenizer.
-anilino-3-methyl-N-methyl-N-cyclohexylaminofluorane fraction i 5 g, bisphenol A dispersion 10 g, β-naphthylbenzyl ether dispersion 10
A thermosensitive dispersion A was obtained by mixing 15 g of g1 calcium carbonate dispersion.

Urinary 11 Okuhachi ■ Deception Silica-modified polyvinyl alcohol (PVA made by Kuraray ■
R2105) 10% by weight liquid 10 parts Colloidal silica (Snowtex 30 manufactured by Nichichi Kagaku ■) 30% by weight liquid 5 parts Zinc stearate (Hydrin 2-7 manufactured by Middle East Yushi ■) 30% by weight liquid
0.42 parts Paraffin wax (Hydrin P-7 manufactured by Middle East Yushi ■) 30% by weight liquid 0.42
A protective layer solution A was obtained by mixing the two parts.

After applying heat-sensitive dispersion A to high-quality paper with a dry coating weight of 6 g/a, an intermediate layer of sodium alginate (manufactured by Snow Algin SH Fuji Chemical Co., Ltd.) 3 % aqueous solution was applied so that the dry coating amount was 0.5 g/if.

Next, 6 parts of capsule liquid A, coupler/base dispersion A
5.5 parts, polyethyleneimine (average molecular weight 75) 30
% aqueous solution 0.5 part mixed solution with a dry coating amount of 6 g/rrf
After applying the protective layer solution A, the dry coating amount is 2g.
/ A was applied to obtain a recording sheet. The coating was done using a wire bar and then dried in an oven at 50°C.

After thermally printing the obtained recording sheet with low energy (thermal head voltage 15V, printing time O ~ 2.5m5ec)
) and irradiated with light for 10 seconds using a Riff Piece-Pardry 100 model to obtain a diazo coloring layer.

Thereafter, thermal printing was performed using a higher energy than the above-mentioned printing energy. (Thermal head voltage 15V, printing time 2.5
~5 ms e c) The obtained image was a clear two-color print in which the low energy print area was red and the high print energy part was black.

Further, this sheet showed no increase in capri or change in print density even after being stored for a long time.

Comparative Example 1 A recording sheet was obtained in exactly the same manner as in Example 1, except that no intermediate layer was provided.

When the obtained sheet was colored in the same manner as in Example 1, the black color density was slightly lower than in Example 1.

Furthermore, when looking at samples stored for a long period of time, yellow to red fog was observed. When this was printed, the color density of black color was extremely reduced.

Example 2゜Coupler Lu i, 1 ■, polyvinyl alcohol (Kuraray PVA-205) 5
Weight % aqueous solution 170 parts ■, coupler 2-hydroxy-3-naphthoic acid anilide 12 parts 2.4-bis(benzoylacetamide) toluene

Bipartite triphenylguanidine (base)
Mix 6 parts ■ and the following color development aid, and use Dynomil (Willy A. Bacoquin).
A dispersion liquid having an average particle size of 3 μm was obtained by dispersing using A.G. Co., Ltd. (trade name).

The following compound (CIBA Pe
rgascript Red l-6-B)/ -~\' 1-phenyl-1-xylethane 55 parts Methylene chloride 55 parts Sumithorpe 200
(UV absorber manufactured by Sumitomo Chemical ■) 2 parts Takenate D-11ON (manufactured by Takeda Pharmaceutical Company ■ (product name)
) and 100 parts of an 8% by weight aqueous solution of polyvinyl alcohol and 4 parts of distilled water.
After adding it to an aqueous solution consisting of 0 parts, it was emulsified and dispersed at 20'C to obtain an emulsified dispersion with an average diameter of lμ.Next, the obtained emulsion was stirred at 4°C for 3 hours. Capsule liquid B was obtained.

, 'A fl) 8 parts of color developer (a), 4 parts of (b) and 3 parts of (c) represented by the following structural formula are dissolved in 8 parts of 1-phenyl-1-xylylethane and 30 parts of ethyl acetate. did. The obtained developer solution was mixed and emulsified into an aqueous solution of 100 parts of an 8% polyvinyl alcohol aqueous solution, 150 parts of water, and 0.5 parts of sodium dodecylbenzenesulfonate to form an emulsion with a particle size of 0.5μ. A dispersion was obtained.

/ 7,・7 /′ /// 1 analysis 1 [a] Color developer (b) Color developer (C) CH.

``Section''
R2105) 10% aqueous solution 15 parts Colloidal silica (Snowtex 30 manufactured by Nissan Chemical ■) 30% aqueous solution 8.5 parts Zinc stearate (Hydrin Yoke manufactured by Middle East Oil & Fats ■) 30% aqueous solution
0.42 parts paraffin wax (Cellosol D-130 manufactured by Middle East Yushi ■) 22% by weight aqueous solution 0.54 parts silica (Mizukashiru P-832 manufactured by Mizusawa Kagaku ■) 33% by weight aqueous dispersion 1.9 parts were mixed to form a protective layer. Liquid B was obtained.

After corona treatment was applied to a biaxially stretched polyethylene terephthalate film with a thickness of 75μ, produced by Kawaratei no Ni Kou, the capsule liquid 85.0
A mixed solution of 10.0 parts of color developer dispersion A was applied in a dry coating amount of 6.
It was applied so that the ratio was g/rrf.

Next, as an intermediate layer, a 3% by weight aqueous solution of sodium alginate (manufactured by Snow Algin SH Fuji Chemical Co., Ltd.) was applied in a dry coating amount of 0.
After coating at a concentration of 5 g/rrf, 6 parts of capsule liquid, 85.5 parts of coupler/base dispersion, and 1 part of calcium chloride were added.
The dry coating amount of 0.5 parts of 0% by weight aqueous solution is 6g/r.
It was applied so that it would be RF.

Thereafter, protective layer liquid B was applied in a dry coating amount of 2 g/i to obtain a recording sheet.

The coating was performed using a wire bar and then dried in an open air at 50°C.

After thermally printing the obtained recording sheet with low energy (thermal head voltage 15V, printing time θ ~ 2.5m5ec)
), the diazo coloring layer was fixed by irradiation with light for 10 seconds using a Riff Piece Pardry Model 100. Thereafter, thermal printing was performed with a higher energy than the above printing energy (thermal head voltage 15V, printing time 2.5 to 5 m5ec).

The resulting image was a clear two-color print in which the low-energy print area was black and the high-energy print area was red. The image was observed as a clearer image when observed from the side of the transparent sheet opposite to the printed area.

Further, even when this sheet was stored for a long time, there was no increase in capri or change in print density.

Comparative Example 2 A recording sheet was obtained in exactly the same manner as in Example 2, except that polyvinyl alcohol (PVA-205 manufactured by Kuraray ■) was used instead of sodium alginate as the intermediate layer.

When the obtained sheet was colored in exactly the same manner as in Example 2, the color density of the black color was slightly lower than that in Example 1.

In addition, when looking at samples stored for a long period of time, capri was observed in yellow to black. When this was printed, the color density of the black color was extremely reduced.

Claims (1)

[Scope of Claims] 1) In a multicolor recording material in which at least two color-forming layers each of which develops a different hue through a color reaction are provided in a superimposed manner on one side of a support, there is a space between each color-forming layer. A multicolor recording material characterized by having an intermediate layer formed by gelling a water-soluble polyanionic polymer with polyvalent cations. 2) The multicolor recording material according to claim 1, wherein the intermediate layer contains an ionic complex of a water-soluble polyanionic polymer and a water-soluble polycationic polymer.