JPH0456861A - Photosensitive body and color image forming method - Google Patents

Abstract

PURPOSE:To allow the formation of color images on plain paper by laminating a polymer layer contg. a polymerizable monomer, a photopolymn. initiator and a thermally diffusive material, a photosensitive light transmission control layer and an image receiving layer on a base material. CONSTITUTION:The photosensitive body formed by laminating the polymer layer 4 contg. the polymerizable monomer, the photopolymn, initiator and the thermally diffusive material, the photosensitive light transmission control layer 3 and the image receiving layer 5 for accepting the transferred thermally diffusive material on the base material 2 is used. Namely, this photosensitive body is constituted of the three layers; the photosensitive light transmission control layer 3 which forms the distribution of light absorptive compds. corresponding to patterns, the polymerized layer 4 which forms polymerized parts and unpolymerized parts according to the distribution patterns of the light absorptive compds. formed on the control layer 3 and the image receiving layer 5 which accepts the material diffused and transferred from the unpolymerized parts. The color images which are excellent in both lightness and saturation are formed on the plain paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoreceptor for forming a color image, and a method of forming a color image using the photoreceptor.

[Conventional technology]

2. Description of the Related Art In recent years, there has been active development of image forming methods that allow image formation to be performed through simple processing.

For example, a method is known from JP-A-61-69062 and the like in which a dry (thermal) polymerization reaction is caused as a photosensitive reaction trigger of silver halide to form a latent image made of a polymer.

For example, according to Japanese Patent Application Laid-Open No. 62-70836, etc.
A latent image is formed by silver nuclei generated from silver halide through image exposure, and the catalytic action of the silver nuclei is used to convert the reducing agent into an oxidant having a polymerization inhibiting ability different from that of the reducing agent under heating. By doing so, a difference is created in the ability to inhibit polymerization between the reducing agent and the generated oxidant, and a thermal polymerization reaction using a thermal polymerization initiator is caused, forming a latent polymer image corresponding to the difference in ability to inhibit polymerization. method is known.

However, these methods have the disadvantage that it is difficult to obtain good contrast in the polymer latent image.

This drawback is because the redox reaction to generate the oxidant and the polymerization reaction to form the polymer latent image occur in the same heat treatment process, which causes these reactions to become competitive reactions, resulting in This is thought to be because the reaction does not proceed efficiently.

Further, image formation by this method is extremely unstable, for example, even by changing the amount of the reducing agent by a small amount, the area where the polymer is formed becomes an exposed area or an unexposed area.

The polymerized latent image formed by the above method is an image consisting of a polymerized portion and an unpolymerized portion.

In order to obtain, for example, a color image from this polymerized latent image, various methods have been proposed that utilize differences in physical properties between the polymerized portion and the unpolymerized portion.

As such a method, for example, Japanese Patent Application Laid-Open No. 62-7855
No. 2 and JP-A-62-81635 disclose that microcapsules containing a coloring material are contained in a photoreceptor, and the breaking strength of the microcapsules is controlled by forming a polymerized latent image as described above. A method for obtaining a colored image is disclosed.

However, this method using microcapsules
Since the resolution is limited by the particle size of the microcapsules, it is necessary to make the particle size of the microcapsules smaller in order to improve the resolution. However, if the particle size is made too small, it will not be possible to obtain sufficient density, and it will be difficult to coat the microcapsules in a single layer on the support, resulting in multilayer coating, resulting in a color cast in the resulting image. A problem arises.

[Problem to be solved by the invention]

Therefore, the present inventors caused a polymerization reaction in the photoreceptor using light and/or heat, formed a latent image made of polymer, and thermally transferred the internal thermal diffusive substance to the image receptor depending on the degree of polymerization. proposed a recording method for forming color images (Japanese Patent Application No. 18502/1983).

The above method has a problem in that it can only be transferred to a dedicated image receptor that receives the heat-diffusible material to be transferred, and cannot be transferred to plain paper.

An object of the present invention is to provide a photoreceptor capable of forming a color image with excellent brightness and chroma on plain paper without using a dedicated image receptor for receiving a thermally diffusive material to be transferred, and the photoreceptor. An object of the present invention is to provide a color image forming method using the method.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors have discovered that a polymer layer containing at least a polymerizable monomer, a photopolymerization initiator, and a thermally diffusive substance, a photosensitive light transmission control layer, and a photosensitive light transmission control layer are provided on a base material. It has been discovered that the above object can be achieved by using a photoreceptor formed by laminating an image-receiving layer that receives a thermally diffusive material to be transferred.

First, the photoreceptor of the present invention will be explained in detail.

The photoreceptor of the present invention includes a photosensitive light transmission control layer that forms a distribution of a light-absorbing compound according to an image pattern, and a polymerized part and an unpolymerized part according to the distribution pattern of the light-absorbing compound formed in the control layer. The photoreceptor has a three-layer structure including a polymer layer forming a polymer layer, and an image receiving layer receiving a substance diffusely transferred from an unpolymerized area according to a polymerization pattern.

Here, the light-absorbing compound is a substance that absorbs in a wavelength range to which the photopolymerization initiator is substantially sensitive, and mainly refers to a reducing agent or an oxidant generated from the reducing agent.

It may also be a by-product that is produced or disappears from these reactions. Furthermore, it may be a silver image produced by a redox reaction.

A photosensitive light transmission control layer that forms a distribution of light absorption compounds according to an image pattern is a layer that absorbs light in the absorption wavelength range of at least the photosensitive silver halide, organic silver salt, and photopolymerization initiator in the polymerization layer. This includes compounds that are produced or disappeared through imagewise exposure and heating steps.

Examples of photosensitive silver halides that can be used include silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide, which can be used for ordinary photographic emulsions. The film may be subjected to chemical sensitization or optical sensitization treatment as described above. That is, as chemical sensitization, sulfur sensitization, noble metal sensitization, reduction sensitization, etc. can be used, and as optical sensitization, methods using conventionally well-known sensitizing dyes can be applied. Furthermore, the halogen composition within the particles may be uniform or may have a different multilayer structure. Further, two or more types of silver halides having different halogen compositions, grain sizes, grain size distributions, etc. may be used in combination. Furthermore, these may be spectrally sensitized or chemically sensitized with a dye or the like.

Examples of organic silver salts include organic acid silver and triazole silver salts [Fundamentals of Photographic Optics, Non-Silver Salt Edition, P247J and JP-A-59]
Organic silver salts described in JP-A-55429 and the like can be used, and it is preferable to use silver salts with low photosensitivity.

Specifically, they are silver salts with aliphatic carboxylic acids, aromatic carboxylic acids, thiocarbonyl group compounds having a mercapto group or α-hydrogen, and imino group-containing compounds.

Aliphatic carboxylic acids include acetic acid, butyric acid, succinic acid, sebacic acid, adipic acid, oleic acid, linoleic acid, linoleic acid, tartaric acid, valmitic acid, stearic acid, behenic acid, camphoric acid, etc. Silver salts with a small number of carbon atoms are unstable, so those with an appropriate number of carbon atoms are preferred.

Examples of aromatic carboxylic acids include benzoic acid derivatives, quinolinic acid derivatives, naphthalenecarboxylic acid derivatives, salicylic acid derivatives, gallic acid, tannic acid, phthalic acid, phenylacetic acid derivatives, and pyromellitic acid.

As the thiocarbonyl group compound having a mercapto group or α-hydrogen, 3-mercapto-4-phenyl-1,2
, 4-triazole, 2-mercaptobenzimidazole, 2-mercapto-5-aminothiadiazole, 2-
Mercaptobenzothiazole, S-alkylthioglycolic acid (alkyl group having 12 to 22 carbon atoms), dithiocarboxylic acids such as dithioacetic acid, thioamides such as thiostearamide, 5-carboxy-1-methyl-2-phenyl-
Examples include mercapto compounds described in U.S. Pat. No. 4,123,274, such as 4-thiopyridine, mercaptotriazine, 2-mercaptobenzoxazole, mercaptooxadiazole, or 3-amino-5-benzylthio-1,2,4-triazole. It will be done.

As a compound containing an imino group, Japanese Patent Publication No. 44-30
Benzotriazole or its derivatives described in No. 270 or No. 45-18416, such as benzotriazole, alkyl-substituted benzotriazoles such as methylbenzotriazole, halogen-substituted benzotriazoles such as 5-chlorobenzotriazole, carboxyl-substituted benzotriazoles such as butylcarboimidobenzotriazole, etc. imidobenzotriazoles,
Nitrobenzotriazoles described in JP-A No. 58-118639, sulfobenzotriazole, carboxybenzotriazole or a salt thereof, or hydroxybenzotriazole described in JP-A-58-115638, etc.
Typical examples include 1,2,4-triazole, IH-tetrazole, carbazole, saccharin, imidazole and derivatives thereof described in US Pat. No. 4,220,709.

As the reducing agent that can be used in the present invention, there can be used reducing agents described in "Basics of Photographic Optics, Non-Silver Salt Edition, p. 250J, secondary color developing agents, secondary color developing agents, etc. These include, for example. , phenols, hydroquinones, catechols, p-aminophenols, p-substituted amine phenols, p-phenylenediamines, 3-pyrazolidones, etc., as well as resorcinols, pyrogallols, 0-aminophenols, m -Aminephenols, m-phenylenediamines, 5-pyrazolones, alkylphenols, alkoxyphenols, naphthols, aminonaphthols, naphthalenediols, alkoxynaphthols, hydrazines, hydrazones, hydroxychromans/hydroxyclamans , sulfonamidophenols, aminonaphthols, ascorbic acids, hydroxyindanes, bisphenols, orthobisphenols, and the like can be used.

Furthermore, leucobase obtained by reducing a dye can also be used as a reducing agent. Furthermore, it is also possible to use a combination of two or more of the above-mentioned reducing agents. When using a secondary color developing agent, it is desirable to use a coupler that reacts with these oxidation products to form a light-absorbing compound.

Specific examples of reducing agents include hydroquinone, hydroquinone methyl ether, 2,4-dimethyl-6
-t-butylphenol, catechol, dichlorocatechol, 2-methylcatechol, methyl gallate, ethyl gallate, propyl gallate, o-amine phenol,
3.5-dimethyl-2-aminophenol, p-aminephenol, p-amino-0-methylphenol, m-
Dimethylaminophenol, m-diethylaminephenol, 2,6-dicyclohexyl-4-methylphenol, ■-naphthol, 2-methyl-1-naphthol, 2
．． 4-dichloro-1-naphthol, 1,1-di-2-naphthol, 2,2-methylenebis (4-methyl-6
-t-butylphenol), 2,2°-methylenebis(
4-ethyl-6-t-butylphenol), 2,2°-
Butylidene bis(4-methyl-6-t-butylphenol), 4,4°-butylidene bis(3-methyl-6-t
-butylphenol), 4,4°-methylenebis(2,
6-di-t-butylphenol), 2,6-di-t-butyl-4(2-hydroxy-3-t-butyl-5-methylbenzyl)phenol, 1,1.3-tris(2-methyl-4- Hydroxy-5-t-butylphenol)butane, 4,4-thiobis(3-methyl-6-t-butylphenol), 2,4-bis(ethylthio)-6-(
4-Hydroxy-3,5-di-t-butylanilino)-
1,3,5-triazine, 2,4-bis(octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-1-riazine, 2,6-dichloro -4-benzenesulfonamidophenol, 2-chloro-4-benzenesulfonamidophenol, 2.6
-dipromo 4-pensene sulfonamidophenol,
Thioindoxyl, indoxyl, 1,3-dimethylpyrogallol, 4-methoxynaphthol, 4-ethoxynaphthol, 2-cyanoacetylchroman, N,N-dimethylphenylenediamine, N,N-diethylphenylenediamine, N' N- Examples include diethyl-3-methylphenylenediamine.

In addition, when a secondary color developing agent (e.g., phenylene diamine type, p-amine phenol type) is used, examples of the coupler include 1-hydroxy-N-butyl-2
- Natutamide, benzoylacetone, benzoylacetanilide, 0-methoxybenzoylaceto-0-methoxyanilide, dibenzoylmethane, 2-chloro-1-naphthol, 2,6-dipromo-1,5-naphthalenediol, 3-methyl-1- Examples include phenylpyrazolone.

The light-absorbing compound may or may not fall within the category of a dye, as long as it can substantially desensitize the sensitivity of the photopolymerization initiator. For example, when absorption in the ultraviolet region is used, absorption in the visible region is not a problem.

As a specific example of a combination of a light-absorbing compound and a photopolymerization initiator, for example, 4,4°-butylidene bis(
3-methyl-6-t-butylphenol), 4,4°-
When methylenebis(2,6-di-t-butylphenol) or the like is used, a photopolymerization initiator sensitive to 380 to 390 nm, such as 2-chlorothioxanthone,
2-Methylthioxanthone, 2.4-dimethylthioxanthone, 2.4-diethylthioxanthone, 2.4.6
- Trimethylbenzoyldiphenylphosphine oxide, benzyl, etc. can be used. 2.4-bis(ethylthio)-6-(4-hydroxy-3,5-di-t-
butylanilino)-1,3,5-triazine, 2,4-
Bis(octylthio)-6-(4-hydroxy-3,5
-Di-t-butylanilino)-1,3,5-triazine and the like, which form cyan dyes with secondary color developing agents, are photopolymerization initiators sensitive to 300 to 340 nm in addition to the visible region, such as 1 -Phenyl-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, benzoin dimethyl ether, benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, etc. can be used.

In addition to these photosensitive silver salts and reducing agents, the photosensitive light transmission control layer may contain binders, color toning agents, antifoggants, photochromic inhibitors, solid solvents, surfactants, antistatic agents, etc. as necessary. can be added.

The polymerization layer, which forms a polymerization pattern according to the distribution of light-absorbing compounds in the photosensitive light transmission control layer, contains a photopolymerization initiator, a polymerizable monomer, and heat that cause a photopolymerization reaction and form a polymerized portion and an unpolymerized portion. A diffusible substance is an essential component.

Examples of the thermally diffusible substances contained in the polymerized layer of the present invention include monoazo dyes, thiazoleazo dyes, anthraquinone dyes, triallylmethane dyes, rhodamine dyes, naphthol dyes, triarylmethane dyes, fluoran dyes, and phthalide dyes. Examples include dyes.

In general, the lower the molecular weight of a thermally diffusible substance, the higher the thermal diffusivity, and for example, dyes with many polar groups such as carboxyl groups, amino groups, hydroxyl groups, nitro groups, and sulfone groups have lower thermal diffusivity. Therefore, depending on the crosslinking density and heating conditions in the polymerized layer of the photoreceptor of the present invention, a thermally diffusive substance having a desired thermal diffusivity may be appropriately selected based on molecular weight and functional group.

In the present invention, as the polymerizable monomer contained in the polymerization layer of the photoreceptor, compounds having at least one reactive vinyl group in the molecule can be used, such as reactive vinyl group-containing monomers, reactive vinyl One or more selected from the group consisting of group-containing oligomers and reactive vinyl group-containing polymers can be used.

The reactive vinyl groups of these compounds include styrene vinyl groups, vinyl acrylate groups, vinyl methacrylate groups, allyl vinyl groups, vinyl ethers, and ester vinyl groups such as vinyl acetate, which have polymerization reactivity. Examples include substituted or unsubstituted vinyl groups.

Specific examples of polymerizable monomers that satisfy these conditions are as follows.

For example, styrene, methylstyrene, chlorstyrene,
Bromostyrene, methoxystyrene, dimethylaminostyrene, cyanostyrene, nitrostyrene, hydroxystyrene, aminostyrene, carboxystyrene, acrylic acid, methyl acrylate, ethyl acrylate, cyclohexyl acrylate, acrylamide, methacrylic acid,
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, vinylpyridine, N
-vinylpyrrolidone, N-vinylimidazole, 2-vinylimidazole, N-methyl-2-vinylimidazole, propyl vinyl ether, butyl vinyl ether,
Monovalent monomers such as isobutyl vinyl ether, β-chloroethyl vinyl ether, phenyl vinyl ether, p-methylphenyl vinyl ether, p-chlorophenyl vinyl ether: e.g. divinylbenzene, distyryl oxalate, distyryl malonate, distyryl succinate, glutaric acid Distyryl, distyryl adipate, distyryl maleate, distyryl fumarate, β, β°-distyryl dimethylglutarate, distyryl 2-bromoglutarate, α, α゛-distyryl dichloroglutarate,
Distyryl terephthalate, dioxalate (ethyl acrylate), dioxalate (methyl ethyl acrylate), dimalonate (ethyl acrylate), dimalonate (methyl ethyl acrylate), disuccinate (ethyl acrylate), diglutarate ( ethyl acrylate), diadipate (ethyl acrylate), dimaleic acid (ethyl acrylate), difumaric acid (ethyl acrylate), β
, β°-dimethylglutarate di(ethyl acrylate)
, ethylene diacrylamide, propylene diacrylamide, 1.4-phenylene diacrylamide, 1.4-
Phenylene bis(oxyethyl acrylate), 1.4
-Phenylenebis(oxymethylethyl acrylate)
, l, 4-bis(acryloyloxyethoxy)cyclohexane, 1,4-bis(acryloyloxymethylethoxy)cyclohexane, 1,4-bis(acryloyloxyethoxycarbamoyl)benzene, 1,4-bis(acryloyloxymethylethoxycarbamoyl) ) Benzene, 1,4-bis(acryloyloxyethoxycarbamoyl)cyclohexane, bis(acryloyloxyethoxycarbamoylcyclohexyl)methane, di(ethyl methacrylate) oxalate, di(methyl ethyl methacrylate) oxalate, di(ethyl methacrylate malonate) , malonic acid di(methyl ethyl methacrylate)
, di(ethyl methacrylate) succinate, di(ethyl succinate), di(succinate)
Methyl ethyl methacrylate), glutaric acid di(ethyl methacrylate), adipic acid di(ethyl methacrylate), maleic acid di(ethyl methacrylate), fumaric acid di(ethyl methacrylate), fumaric acid di(methyl ethyl methacrylate), β, β′ - Divalent monomers such as dimethylglutarate di(ethyl methacrylate), 1,4-phenylene bis(oxyethyl methacrylate), 1,4-bis(methacryloyloxyethoxy)cyclohexane acryloyloxyethoxyethyl vinyl ether 1, e.g. pentaerythritol triacrylate,
Pentaerythritol trimethacrylate, pentaerythritol tri(hydroxystyrene), dipentaerythritol hexaacrylate, cyanuric acid triacrylate, cyanuric acid trimethacrylate, 1.1.1
Trimethylolpropane triacrylate, 1.1.1
- t-rimethylolpropane trimethacrylate, cyanuric acid tri(ethyl acrylate), 1.1.1
-Trimethylolpropane tri(ethyl acrylate)
, cyanuric acid tri(ethyl vinyl ether), 1,1
．． Trivalent monomers such as condensates of 1-trimethylolpropane tri(toluene diisocyanate) and hydroxyethyl acrylate, and condensates of 1.1.1-trimethylolpropane tri(hexane diisocyanate) and p-hydroxystyrene : For example, 4 such as ethylene tetraacrylamide, propylene tetraacrylamide, etc.
In addition, examples of polymerizable monomers include polymerizable monomers such as oligomers or polymers with reactive vinyl groups left at their ends, or oligomers or polymers with reactive vinyl groups attached to their side chains. Note that two or more types of these polymerizable monomers may be used.

Examples of the photopolymerization initiator contained in the polymerization layer of the photoreceptor of the present invention include carbonyl compounds, sulfur compounds, halogen compounds, redox photopolymerization initiators, and the like.

Specifically, carbonyl compounds include diketones such as benzyl, 4,4°-dimethoxybenzyl, diacetyl, and camphorquinone; benzophenones such as 4.4°-diethylaminobenzophenone and 44-dimethoxybenzophenone; for example, acetophenone; , acetophenones such as 4-methoxyacetophenone; benzoin alkyl ethers; for example, thioxanthone such as 2-cyclothioxanthone, 2,5-diethylthioxanthone, thioxanthone-3-carboxylic acid-β-methoxyethyl ester; dialkylamino group; Chalcone and styryl ketones with: 3.3゛-
Examples include coumarins such as carbonylbis(7-medoxycoumarin) and 3,3-carbonylbis(7-dinithylaminocoumarin).

Examples of the sulfur compound include dibenzothiazolyl sulfide, decylphenyl sulfide, and disulfides.

Examples of halogen compounds include carbon tetrabromide, quinolinesulfonyl chloride, and S-
Examples include triazines.

Redox-based photopolymerization initiators include those used in combination with trivalent iron ion compounds (e.g. ferric ammonium citrate) and peroxide, and those used in combination with photoreducible dyes such as riboflavin and methylene blue and triethanolamine. , those using a combination of reducing agents such as ascorbic acid, and the like.

Further, among the photopolymerization initiators described above, two or more types can be combined to perform photopolymerization with higher efficiency.

Examples of such a combination of photopolymerization initiators include a combination of chalcones, styryl ketones, and coumarins having a dialkylamino group, and s-triazines and camphorquinone having a triheromethyl group.

The image-receiving layer of the present invention functions to receive diffusely transferred substances, such as polyester resin, polycarbonate resin, polyvinyl acetate resin, polyurethane resin, polyamide resin, polycaprolactam resin, polyvinyl chloride resin,
Polyacrylic ester resins, styrene-acrylate resins, styrene-maleic anhydride resins, polyacrylonitrile resins, etc. can be used.

The preferred blending ratio of the above components in the photoreceptor of the present invention is as follows.

Preferably 0 silver halide per mol of organic silver salt
．． It is desirable to contain 0.001 to 2 moles, more preferably 0.05 to 0.4 moles. Further, it is desirable to contain the reducing agent preferably in an amount of 0.2 to 3 mol, more preferably 0.7 to 1.3 mol, per mol of the organic silver salt.

For the polymerization layer, it is preferable to use a photopolymerization initiator in an amount of 0.1 to 30 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer. Further, the content of the thermally diffusive substance is preferably 2.5 to 100 parts by weight, more preferably 5 to 50 parts by weight, based on the total of 100 parts by weight of the polymerizable photopolymerization initiator and the appropriately contained binder. Parts by weight.

To form the photoreceptor of the present invention, the materials constituting each of the above layers are dispersed and dissolved in a solvent, and the above three layers are placed on a support such as metal foil, plastic film, paper, baryta paper, or synthetic paper.
The layers can be formed by sequential coating and drying. Furthermore, if each layer itself has film properties, it can also be manufactured by forming each layer into layers and laminating them without a support. The order of lamination is not particularly limited, but considering that the image-receiving layer is transferred over the entire surface in the final step of the color image forming method described later, it is preferable that the image-receiving layer is the uppermost layer. FIG. 1 shows one embodiment of the photoreceptor of the present invention. In the figure, a photoreceptor 1 has a structure in which a photosensitive light transmission control layer 3, a polymer layer 4, and an image receiving layer N5 are sequentially laminated on a support 2.

Note that the shape of the photoreceptor of the present invention includes a flat plate, a cylindrical shape,
It is not particularly limited to a roll shape or the like. The thickness of each layer when formed in a layered manner is 0.5 μm to 0.5 μm, preferably 1 μs to 0.1 μm for the photosensitive light transmission control layer.
mm, the polymer layer has a thickness of 0.5 gm to 0.5 mm, preferably l- to 0.1 mm, and the image-receiving layer has a thickness of 0.5 to 10 gm.
0μ, preferably 1 to 50μ.

The binder that can be used in the present invention can be selected from a wide range of resins, but specific examples include nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose myristate. , cellulose palmitate,
Cellulose esters such as cellulose acetate/propionate, cellulose acetate/butyrate; cellulose ethers such as methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose; e.g. polystyrene, polyvinyl chloride, polyvinyl acetate, polyvinyl butyral, polyvinyl acecool, Vinyl resins such as polyvinyl alcohol and polyvinylpyrrolidone; for example, copolymer resins such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer; for example, polymethyl methacrylate, polymethyl Acrylate, polybutyl acrylate,
Acrylic resins such as polyacrylic acid, polymethacrylic acid, polyacrylamide, and polyacrylonitrile; Polyesters such as polyethylene terephthalate:
For example, poly(4,4-isopropylidene, diphenylene-2-1,4-cyclohexylene dimethylene carbonate), poly(ethylenedioxy-3,3-phenylenethiocarbonate), poly(4,4°-isobropylidene di phenylene carbonate coaterephthalate),
Poly(4,4°-isopropylidene diphenylene carbonate), poly(4,4-sec-butylidene diphenylene carbonate), poly(4,4°-isopropylidene diphenylene carbonate-block-oxyethylene), etc. Polyacrylate resins: polyamides; polyimides; epoxy resin B: phenolic resins; polyolefins such as polyethylene, polypropylene, chlorinated polyethylene; and natural polymers such as gelatin.

Next, the color image forming method of the present invention will be explained based on the drawings. FIG. 2 shows an outline of the color image forming method of the present invention.

For the photoreceptor having the structure shown in FIG. 1, (a) the step of imagewise exposing the photosensitive light transmission control layer 3 to form a latent image 7 on the photosensitive silver salt 6, and (b) heating. and generates a compound 9 that absorbs light in the absorption wavelength range of the photopolymerization initiator in the polymerization layer 4 (
In the figure, the oxidized form of the reducing agent 8) or disappears, and the light-absorbing compound is generated in the generated area (exposed area 3-a) and the ungenerated area (unexposed area 3-a).
-b), (c) performing full-surface exposure so that light is irradiated on the polymer layer 4 through the photosensitive light transmission control layer 3, and forming a distribution in the polymer layer according to the distribution of the light-absorbing compound. a step of polymerizing the polymerizable monomer of and forming a distribution according to a polymerization latent image (unpolymerized part 4-a, polymerized part 4-b), (d)
a step of heating the photoreceptor and transferring the thermally diffusive substance 10 in the unpolymerized portion 4-a in the polymerized layer 4 to the image-receiving layer 5 to form a color image 11; (e) receiving image with the color image 11 formed; Layer 5 and an image receptor 12 such as plain paper are pasted together, and a thermally diffusive substance l is applied to the image receptor 12.
It consists of a step of transferring O.

In the method of the present invention including each of the above steps, since silver halide is used, the sensitivity in writing a latent image by silver nuclei is excellent, and since the method of forming the polymer is full exposure, it takes only a short time. Processing time in each step of image formation from writing to development can be efficiently shortened.

Furthermore, since the process of producing the light-absorbing compound and the process of forming the polymer are effectively separated, it is possible to obtain a sufficiently stable contrast between the exposed area and the unexposed area.

In addition, the material can be selectively diffused and transferred to the image-receiving layer according to the difference in thermal diffusivity of the thermally diffusible substance caused by the degree of crosslinking between the polymerized portion and the unpolymerized portion of the polymerized layer.
The silver image and color image formed in the amplification step are separated, and the resulting color image is free from turbidity and has excellent chroma and brightness.

The step (a) above is a step of writing an image with light, and as shown in FIG. 2, the photosensitive light transmission control layer 3 of the present invention formed on the support 2 is subjected to image exposure or digital exposure to expose the desired image. As a result, silver nuclei are generated on the photosensitive silver halide in the exposed area, forming a latent image 7. Note that the generated silver nuclei become a catalyst for the thermal reaction between the organic silver salt contained in the photosensitive light transmission control layer 3 and the reducing agent.

The exposure conditions for writing this latent image depend on the concentration of silver halide contained in the recording material layer, etc., so that the desired characteristics such as sufficient contrast can be obtained in the polymerized latent image obtained. It is only necessary to select and use them as appropriate.

Since photosensitive silver halide is used in this process,
Highly sensitive writing is possible.

Next, in the above step (b), when the photosensitive light transmission control layer 3 on which the latent image has been formed is heated, the silver nuclei selectively act as a catalyst in the exposed areas as shown in FIG. The salt and reducing agent 8 react, and the organic silver salt is reduced to silver atoms, and at the same time, the reducing agent 8 is oxidized to become a light-absorbing compound (oxidant) 9.

The heating in step (b) is carried out by appropriately selecting conditions necessary for the progress of the redox reaction. Although it cannot be generalized depending on the composition of the photoreceptor, heat treatment may be performed at 60°C to 200°C, more preferably 70°C to 150°C, for 1 second to 5 minutes, more preferably 3 seconds to 60 seconds. . - When fishing on a boat at high temperatures, it only takes a short time to heat, but at low temperatures it takes a long time to heat. As a heating means, in addition to a method using a hot plate, a heat roll, a thermal head, etc., a method of heating by supplying electricity to a heating element of a support, a method of heating by laser beam irradiation, a method of heating by dielectric heating, etc. can be used.

Subsequently, in step (c) above, the entire surface is exposed from the photosensitive light transmission control layer 3 side to cleave the photopolymerization initiator contained in the polymerization layer 4 and generate radical species. A polymerization reaction occurs due to these radical species, and a portion of the polymer is formed in the polymerized layer 4. At this time, since the amount of light transmitted in the wavelength range absorbed by the photopolymerization initiator is different between the exposed area 3-a and the unexposed area 3-b,
A distribution of polymerized latent images (unpolymerized portion 4-a, polymerized portion 4-b) is formed.

As the light source used in the above steps (a) and (C), for example, sunlight, a tungsten lamp, a mercury lamp, a halogen lamp, a xenon lamp, a fluorescent lamp, an LED, a laser beam, etc. can be used, and the wavelength of the light used in these steps is the same. may be different. Incidentally, even if light of the same wavelength is used in steps (a) and (c), since silver halide usually has a sufficiently higher photosensitivity than the photoinitiator, photopolymerization does not occur in step (a). A sufficient latent image can be written with light of a moderate intensity.

Furthermore, in step (c) above, a means for heating the image forming body during exposure may be used. This may be done by newly heating or by using residual heat from the step (b) above.

Next, in step (d), as shown in the figure, it is heated appropriately. A thermally diffusive substance 10 exists in the polymerized layer 4, and a thermally diffusive substance 10 exists in the polymerized portion 4-b of the polymerized layer 4.
Since the thermal diffusivity of the substance 10 present in the unpolymerized portion 4-a is suppressed in the polymerized layer, the thermal diffusivity of the unpolymerized portion 4-a is suppressed by the heating. sexual substance lO
is selectively diffused and transferred.

The diffusivity of the thermally diffusive substance IO in the polymerization part 4-b is suppressed by polymerization of the polymerizable monomer or by crosslinking of the polymerizable monomer when it contains a polyfunctional polymerizable monomer. Even if the polymerization part 4-b is heated, the molecular chains of the polymer are difficult to relax, and the thermal diffusive substance 10
This is because it prevents the spread of

The heating temperature in step (d) is preferably 80 to 250°C, preferably 80 to 200°C, although the suitable value varies depending on various conditions such as the type of thermally diffusive substance and the degree of polymerization of the polymer. ℃, and preferably higher than the heating temperature in step (b).

After passing through the above steps, a color image 11 made of the thermally diffusive substance 1O is obtained in the image receiving layer 5, and after this image receiving layer 5 is laminated to an image receiving member 12 such as plain paper, the image receiving layer 11 of the photoreceptor is After removing the layer, the color image can be transferred onto plain paper by heating from the image-receiving layer side.

This image has excellent contrast, and since no silver is mixed in, the image has excellent brightness and chroma that are not affected by the black color of the silver image.

[Example] Next, the present invention will be explained by examples.

Silver bromide 1.2 parts Behenic acid
4.0 parts silver behenate
7.0 parts polyvinyl butyral
1000 parts 4.4-methylenebis (2,6-di-butylphenol) 0.5 parts Toluene-n-butanol 150 parts The above formulation was thoroughly dissolved and dispersed using a paint shaker,
Solution A was prepared. Solution A was applied to a 22-scale anchor-treated polyester film to give a dry film thickness of 4 to 5 μm to form a photosensitive light transmission control layer.

Thermal diffusive substance MS Magenta VP 2.5 parts (manufactured by Mitsui Toatsu Dye) Photopolymerization initiator 24-diethylthioxanthone 1.5 parts Ethyl dimethylaminobenzoate 1.0 parts Polymerizable monomer trimethylolpropane triacrylate 10 parts Binder Polymethyl methacrylate 10 parts Solvent ethanol-methyl ethyl ketone 75 parts Weigh out the above formulation and thoroughly dissolve it in an ultrasonic disperser to obtain liquid B, which is coated on the previously coated photosensitive light transmission control layer with a dry film thickness of 5 to 6 μm. A polymerized layer was obtained by coating so that the following was obtained.

Water-dispersed polyester resin 30 parts (Pyronal 300, manufactured by Toyobo ■) Ion-exchanged water
70 parts The above formulation was stirred to obtain Solution C, which was coated onto any polymer layer to a dry film thickness of 3 to 4 μm to form an image-receiving layer, thereby producing a photoreceptor of the present invention.

A lithium film was placed on the photoconductor of the present invention prepared in this manner, and a fluorescent lamp having a fluorescence peak at 340 nm was placed at a distance of 5 cm.
Imagewise exposure was carried out for 2 seconds from a distance of .

The lithographic film was removed, and the photoreceptor was passed through a heat developing machine adjusted to 105° C. for 30 seconds. Further, it was placed on a hot plate heated to 60° C., and a fluorescent lamp with a power consumption of 10 W having a fluorescence peak at 390 nm was irradiated for 40 seconds from a distance of 1 cm.

Next, heat from the support side at 130°C for 20 seconds,
A thermally diffusive substance was diffused and transferred from the polymerization layer to the image-receiving layer, and a red dye image corresponding to the image-exposed area was formed on the image-receiving layer.

A clear red dye image was obtained on the plain paper by stacking plain paper (Canon NP copy paper) and the image-receiving layer in direct contact with each other, heating, and transferring the image-receiving layer to the plain paper.

〔Effect of the invention〕

As explained above, by using the photoreceptor of the present invention and applying the method of the present invention, it is possible to print on plain paper with high sensitivity, high resolution, good contrast in dry processing, and both brightness and chroma without color fog. Excellent color images can now be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing one embodiment of the photoreceptor of the invention, and FIG. 2 is a schematic sectional view showing an embodiment of each step of the color image forming method of the invention. 1...Photoreceptor 2...Support 3...
Photosensitive light transmission control layer 3-b...Unexposed area 4...Polymerized layer 4-b...Polymerized area 5...Image receiving layer 7...Latent image 9...Light-absorbing compound 11. ...Color image 3-a...Exposed area 4-a...Unpolymerized area 6...Photosensitive silver salt 8...Reducing agent 1O...Thermodiffusive substance 12...Image receptor No. Yu figure

Claims (1)

[Scope of Claims] 1. A photoreceptor formed by laminating, on a base material, a polymer layer containing at least a polymerizable monomer, a photopolymerization initiator, and a thermally diffusive substance, a photosensitive light transmission control layer, and an image receiving layer. . 2. The photosensitive light transmission control layer is formed by imagewise exposure and heating steps of a compound that absorbs light in the absorption wavelength range of at least the photosensitive silver halide, organic silver salt, and photopolymerization initiator in the polymerization layer. or a compound that disappears. 3. A step of (a) imagewise exposing the photoreceptor according to claim 2; (b) a step of heating to generate or eliminate a compound that absorbs light in the absorption wavelength range of the photopolymerization initiator in the polymerization layer. (c) a step of exposing the entire surface of the polymerized layer to light through the photosensitive light transmission control layer and polymerizing the polymerizable monomer in the polymerized layer according to the distribution of the light-absorbing compound to form a polymerized latent image; (d) photosensitive (e) transferring the heat-diffusible substance from the image-receiving layer to the image-receiving paper; Characteristic color image forming method.