JPH0365951A - Photoreceptor and image forming method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a silver salt-based photoreceptor for forming images using heat-diffusible dyes, etc., and an image forming method using the photoreceptor. [Prior Art] Energy used to form or record images includes light, sound, electricity, magnetism, heat, particle beams (electron beams, X-rays), and chemical energy.
Electricity, thermal energy, or a combination of these are often used. For example, image forming methods using a combination of light energy and chemical energy include methods using silver salt photography, diazo copying paper, and the like. Further, as a method using a combination of light energy and electric energy, there is an electrophotographic system. Furthermore, methods of utilizing thermal energy include methods using thermal recording paper, transfer recording paper, etc.
As methods that utilize electrical energy, methods using electrostatic recording paper, current-carrying recording paper, discharge recording paper, etc. are known. Among the image forming methods described above, silver salt photography is one that allows high resolution images to be obtained. However, silver salt photography requires complex development and fixing processes using liquid agents, drying processes for images (prints), and the like. Therefore, efforts are being made to develop image forming methods that can form images through simple processing. For example, Japanese Patent Application Laid-open No. 61-69062 discloses a method of causing a dry (thermal) polymerization reaction as a trigger for the photosensitive reaction of silver halide to form a latent image consisting of polymerized and unpolymerized areas. There is. Although this method has the advantage of not requiring complicated wet processing, it has the disadvantage that the polymerization formation rate (polymerization rate of the polymerizable compound) is slow and it takes time to form a polymerized latent image. This drawback is that during the heat treatment process, the reaction intermediate (which functions as a polymerization initiator) generated from the reaction between the silver produced from the silver halide by image exposure and the reducing agent is extremely stable and has no activity as a polymerization initiator. This is thought to be because the polymerization reaction is difficult to proceed quickly due to the low On the other hand, in order to accelerate the polymerization rate, JP-A-62-70836 discloses a method in which a thermal polymerization initiator is used in combination. In this method, 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 oxidize a reducing agent, which has a polymerization inhibiting ability different from that of the reducing agent, under heating. By converting the reducing agent into the oxidant, a difference in polymerization inhibiting ability is created between the reducing agent and the generated oxidant, and a thermal polymerization reaction using a thermal polymerization initiator is caused, resulting in a difference in polymerization inhibiting ability. This is a method of forming a polymerized latent image according to the However, this method has the disadvantage that it is difficult to obtain good contrast in the polymerized latent image. This drawback is because the redox reaction to generate the oxidant and the polymerization reaction to form the polymerized 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 No. 62-81635 disclose that microcapsules containing a coloring material are contained in an image forming body,
A method is disclosed in which a colored image is obtained by forming a polymerized latent image as described above and controlling the breaking strength of the microcapsules. In other words, the method involves creating a difference in the breaking strength of the microcapsules due to the difference in rigidity between the polymerized and unpolymerized parts of the polymerization latent image, and then applying an appropriate pressure to selectively destroy the microcapsules to initiate the coloring reaction. This is a way to raise the issue. Previously, such methods were considered suitable for obtaining color images from polymerized latent images. However, the resolution of the above-mentioned methods using microcapsules is limited by the particle size of the microcapsules. Therefore, in order to improve the resolution, it is necessary to make the particle size of the microcapsules smaller. However, if the particle size is made too small, the density will not be sufficient and it will be difficult to coat the microcapsules on the support in a single layer, resulting in a color cast in the image obtained when the microcapsules are coated in multiple layers. A problem arises.

[Problem to be solved by the invention]

The present inventors have developed a method for causing a polymerization reaction in a photoreceptor through imagewise exposure, heating, and full-surface exposure to form a latent image made of a polymer, and a method for forming a latent image made of a polymer by applying the polymer latent image to beer-apart, inking, and toning. proposed a method of visualizing images by
55, No. 63-183441, No. 63-251958). Furthermore, photoreceptors and image forming methods capable of producing color images with excellent brightness and chroma without being affected by the color of silver images produced during imagewise exposure and heating, as well as photosensitive silver halides, organic silver salts, etc. , a photoreceptor consisting of a reducing agent, a polymerizable polymer precursor, a polymerization initiator, and a heat-diffusive substance, and the photoreceptor is subjected to imagewise exposure, heating, and full-surface exposure and/or heating for polymerization to form a polymer latent image. We proposed a method of forming an image made of a heat-diffusible material on the image receptor by heating the material, laminating it on the image receptor, and transferring the internal thermal diffusivity to the image receptor depending on the degree of polymerization (patent application). (Sho 63-207230). The purpose of the present invention is to have good contrast, excellent resolution,
An object of the present invention is to provide a photoreceptor with improved color cast and an image forming method. [Means for Solving the Problems] First, the photoreceptor of the present invention will be explained. The photoreceptor of the present invention comprises, on a base material, a polymer layer containing at least a polymerizable polymer precursor, a photopolymerization initiator, and a thermally diffusive substance, and at least a photosensitive silver halide, an organic silver salt, and a polymer layer containing at least a photosensitive silver halide, an organic silver salt, and A light-absorbing compound that absorbs light in the absorption wavelength range of the photopolymerization initiator and is generated or disappears through the process of image exposure and thermal development, a polymerizable polymer precursor, and a photopolymerization initiator contained in the polymerization layer. This is a photoreceptor having a photosensitive layer containing a photopolymerization initiator having an absorption wavelength range that is the same as or near the absorption wavelength range of . A preferred embodiment of the photoreceptor of the present invention is one in which a polymerized portion and an unpolymerized portion satisfying the following formula (A) can be formed in the polymer layer. Tgz 7g+230°C ・・・・・・(A) (In the formula, Tgr is the glass transition temperature of the unpolymerized part, Tgz
represents the glass transition temperature of the polymerized portion. ) The photoreceptor of the present invention has a photosensitive 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 photosensitive layer. It consists of a two-layer structure with a polymer layer formed. In addition, in the photoreceptor of the present invention, the polymer layer contains a thermally diffusive substance, and the diffusivity of the thermally diffusive substance in the polymerized portion is suppressed, so that the photoreceptor after forming a polymerized latent image is When the image receptors are stacked and heated, the heat-diffusible material in the unpolymerized portion is transferred to the image receptor side. Furthermore, in the photoreceptor of the present invention, since the photosensitive layer also contains a polymerizable polymer precursor and a photopolymerization initiator,
When a latent polymerized image is formed in the polymerized layer (at the time of full-surface exposure), the polymerizable polymer precursor in the photosensitive layer also polymerizes in the unexposed areas of the image. Therefore, when diffusively transferring a thermally diffusive substance to an image receptor through a photosensitive layer, the diffusivity of the thermally diffusive substance in the image-exposed area is more pronounced than when no latent image is formed on the photosensitive layer. can be suppressed to Here, the light-absorbing compound is a substance that has absorption in the wavelength range to which the photopolymerization initiator is substantially sensitive, and is mainly silver produced in a redox reaction, a reducing agent, or an oxidized compound produced from the reducing agent. It is about. It may also be a by-product that is produced or disappears from these reactions. Silver halides that can be used in the photosensitive layer include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide, and silver chloroiodobromide. The halogen composition may be uniform or may have a multiple structure with different halogen compositions. 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 the organic silver salt include 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, palmitic acid, stearic acid, -hepenic acid, camphoric acid, etc. Silver salt with a small number of carbon atoms is unstable for boat fishing, so it is better to use one with an appropriate number of carbon atoms. 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. . 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.
Representative 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 photosensitive layer of the present invention, there can be used the reducing agents described in "Fundamentals of Photographic Optics, Non-Silver Salt Edition, p. 250J, secondary color developing agents, secondary color developing agents, and the like. These include, for example, phenols, hydroquinones, catechols, p-aminophenols, p-substituted aminophenols, p-phenylenediamines, 3-pyrazolidones, resorcinols, pyrogallols, and 0-aminophenols. classes, m-aminophenols,
m-phenylenediamines, 5-pyrazolones, alkylphenols, alkoxyphenols, naphthols, aminonaphthols, naphthalene diols, alkoxynaphthols, hydrazines, hydrazones, hydroxychromans/hydroxyclamans, sulfonamide phenols , 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 monomethyl 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-aminophenol, p-amino-〇-methylphenol, m-
Dimethylaminophenol, m-diethylaminophenol, 2,6-dicyclohexyl-4-methylphenol, l-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), ■. 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-butyl7nilino)-1,3,5-triazine,
2.4-Bis(octylthio)-6-(4-hydroxy-3,5-di-t-butyl7nilino)-,1,3,5-
Triazine, 2,6-dichloro-4-benzenesulfonamidophenol, 2-chloro-4-benzenesulfonamidophenol, 2,6-dibromo-4-benzenesulfonamidophenol, thioindoxyl, indoxyl, 1.3 -dimethylpyrogallol, 4-methoxynaphthol, 4-ethoxynaphthol, 2-cyanoacetylcoumaron, N,N-dimethylphenylenediamine, N
, N-diethylphenylenediamine, N',N'-diethyl-3-methylphenylenediamine, and the like. In addition, when a secondary color developing agent (e.g., phenylenediamine type, p-aminophenol type) is used, examples of the coupler include l-hydroxy-N-butyl-2
- Natutamide, benzoylacetone, benzoylacetanilide, 0-methoxybenzoylaceto-〇-methoxyanilide, dibenzoylmethane, 2-chloro-1-naphthol, 2,6-dibromo-1,5-naphthalenediol, 3-methyl-1 -phenylpyrazolone and the like. The above-mentioned reducing agents are non-light-absorbing compounds that become light-absorbing compounds when converted into oxidants, or reducing agents that convert into light-absorbing compounds by reacting with other reactants at the same time as they are converted into oxidants. Examples (embodiments) of reducing agents. When adopting an embodiment in which a substance other than an oxidized reducing agent is used as a light-absorbing compound, the type of reducing agent is not particularly limited, and various conventionally known reducing agents can be used. Further, a reducing agent that generates a light-absorbing compound and other reducing agents can also be used together. As a particularly preferable reducing agent, the following general formula (I) [Formula (I
), R1 and R2 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted alkynyl group. Represents a cycloalkyl group, a substituted or unsubstituted aralkyl group, m is 1
Indicates an integer of ~3, A is a monovalent to trivalent linking group, substituted or unsubstituted aralkyl group, substituted or unsubstituted alkyl group, substituted amine group, divalent alkylidene group, aralkylidene group, trivalent [representing a methine group] can be mentioned. In the general formula (I), the unsubstituted alkyl group is a linear or branched alkyl group having 1 to 18 carbon atoms, such as methyl, ethyl, propyl, i-propyl, butyl, t-butyl, i
-butyl, amyl, i-amyl, 5ec-amyl, thexyl, hexyl, heptyl, octyl, nonyl, dodecyl, stearyl and the like. Examples of the substituted alkyl group include an alkoxyalkyl group having 2 to 18 carbon atoms, a halogenoalkyl group having 1 to 18 carbon atoms, a hydroxyalkyl group having 1 to 18 carbon atoms, a 7-minoalkyl group having 1 to 18 carbon atoms, and the like. For example, alkoxyalkyl groups include methoxyethyl, ethoxymethyl, ethoxyethyl, ethoxypropyl, ethoxybutyl, propoxymethyl, propoxybutyl, i-propoxypentyl, t-butoxyethyl,
Examples include hexyloxybutyl. Halogenoalkyl groups include chloromethyl, chloroethyl, bromoethyl, chloropropyl, chlorobutyl,
Examples include chlorohexyl and chlorooctyl. Examples of the hydroxyalkyl group include hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyhebutyl, and the like. Examples of aminoalkyl groups include aminomethyl, acetylaminomethyl, dimethylaminomethyl, aminoethyl, acetylaminoethyl, dimethylaminoethyl, diethylaminoethyl, morpholinoethyl, piperidinoethyl,
Diethylaminopropyl, dipropylaminoethyl, acetylaminopropyl, aminobutyl, morpholinobutyl and the like can be mentioned. Examples of the alkenyl group include vinyl, allyl, prenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, and the like. Examples of the alkynyl group include acetyl, propargyl, butynyl, pentynyl, hexynyl, l\butynyl, octenyl, and the like. Examples of the cycloalkyl group include cyclopentyl, cyclohexyl, and cycloheptyl. Examples of the aralkyl group include benzyl and phenethyl. Among these, preferred substituents as R2 are chlorine atom, bromine atom, methyl, ethyl, i-propyl, t-butyl, 5
ec-amyl, thexyl, ethoxymethyl, ethoxyethyl, chloromethyl, hydroxymethyl, aminomethyl, dimethylaminomethyl, benzyl, and particularly preferred substituents are chlorine atom, t-butyl, and thexyl. Preferred substituents for R' are chlorine atom, methyl, ethyl, i-propyl, t-butyl, amyl, thexyl, hydroxyl, chloromethyl, hydroxymethyl, benzyl, and cyclohexyl, and particularly preferred substituents are chlorine atom, They are methyl, t-butyl, and thexyl. Examples of the substituted or unsubstituted aralkyl group of the monovalent linking group include benzyl, p-methoxybenzyl, p-
Nt N-dimethylaminobenzyl, p-pyrrolidinobenzyl, p-methylbenzyl, p~hydroxybenzyl, p-chlorobenzyl, 3.5-dichloro-4=hydroxybenzyl, 2.4-dimethylbenzyl, 2-hydroxy- Examples include 3-t-butyl-5-methylbenzyl and naphthylmethyl. Examples of the substituted or unsubstituted alkyl group of the monovalent linking group include methyl, ethyl, i-propyl, N, N-
Dimethylaminomethyl, N-benzylaminomethyl, methoxymethyl, ethoxymethyl, hydroxymethyl, methoxycarbonylethyl, methoxycarbonylmethyl,
Examples include ethoxycarbonylethyl, diethyl phosphonate methyl, and the like. Examples of the substituted amine group of the monovalent linking group include methylaminodimethylamino, diethylamino, acetylamino, phenylamino, diphenylamino, and triadylamino. Examples of the alkylidene group of the divalent linking group include methylene, ethylidene, propylidene, and butylidene. Examples of the aralkylidene group of the divalent linking group include benzylidene, p-methylbenzylidene, and p-dimethylaminobenzylidene. Among these, preferred linking groups are monovalent aralkyl groups, divalent alkylidene groups, aralkylidene groups, and trivalent methine groups, and monovalent aralkyl groups, divalent alkylidene groups, and aralkylidene groups are particularly preferred linking groups. It is. Specific examples of preferable reducing agents among the reducing agents represented by general formula (I) will be listed, but the present invention is not limited to these reducing agents. 2.4-dimethyl-6-t-butylphenol, 2-methyl-4-i-propyl-6-t-butylphenol,
2.6-di-t-butyl-4-dimethylaminophenol, 2.6-di-t-butyl-4-o-tolylphenol, 2,6-di-t-butyl-4-hydroxymethylphenol, 2-t -Butyl-6-benzyl-4-methylphenol, 2.6-di-t-butyl-4-benzylphenol, 2-t-butyl-4-(p-methoxybenzyl)-5-methylphenol, 2.6- dimethyl-4-
(α-naphthylmethyl)phenol, 2,6-di-t-
Butyl-4-(2-hydroxy-3-t-butyl-5-
methylbenzyl)phenol, 2-t-butyl-4-(
p-chlorobenzyl)-6-cyclohexylphenol, 2-t-butyl-4-(2-hydroxy-3,5-dimethylbenzyl)-5-methylphenol, 2-t-butyl-4-benzyl-6- Propargylphenol, 2.
6-di-t-butyl-4-(3,5-dichloro-4-hydroxybenzyl)phenol, 2,6-ditexy-4-(4-hydroxybenzyl)phenol, 2-texy-4-benzyl-5-methylphenol, 2 -Allyl-4-benzyl-5-methylphenol, 2-axyl-4-(p-chlorobenzyl)-5-allylphenol, 2-chloro-4-dimethylaminophenol, 2,
6-di-i-propyl-4-diethylaminophenol, 2-butyl-4-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenol, 3.3"-di-t-butyl-4 4'-dihydroxydiphenylmethane, 4.4'-methylenebis(2,6-di-t-butylphenol), 4.4'-methylenebis(2-t-butyl-5-methylphenol), 4.4'-methylenebis( 2-t-butyl-6-methylphenol), 4,
4°-methylenebis(2-axyl-6-methylphenol), 4,4°-methylenebis(2-cyclohexyl-6-methylphenol), 4,4°-methylenebis(2-cyclohexyl-6-t-butylphenol),
4.4°-ethylidenebis(2,6-di-t-butylphenol), 4,4°-ethylidenebis(2-t-butyl-6-methylphenol), 4.4°-ethylidenebis(2-cyclohexyl- 6-methylphenol), 4
．． 4'-ethylidenebis(2-axyl-6-methylphenol), 4,4°-propylidenebis(2,6-di-t-butylphenol), 4,4°-butylidenebis(2-t-butyl-6-methylphenol) ), 4.4
'-Butylidenebis(2-axyl-6-methylphenol), 4,4°-butylidenebis(2-cyclohexyl-6-methylphenol), bis(3,5-di-t-
Butyl-4-hydroxyphenyl)phenylmethane, bis(3,5-di-t-butyl-4-hydroxyphenyl)(4-methoxyphenyl)methane, bis(3,5-di-t-butyl-4-hydroxy phenyl)(4-dimethylaminophenyl)methane, tris(3,5-di-t-
Butyl-4-hydroxyphenyl)methane, bis(3-
Examples include t-butyl-4-hydroxy-5-methylphenyl)phenylmethane. Among these, a particularly preferable reducing agent is 2.6-dit
-butyl-4-o-tolylmethylphenol, 2,6-
Di-t-butyl-4-benzylphenol, 2,6-c-7-butyl-4-(2-hydroxy-3-t-butyl-5-methylbenzyl)phenol, 2-t-butyl-
4-(2-hydroxy-3,5-dimethylbenzyl)-
5-methylphenol, 2,6-di-t-butyl-4-
(3,5-dichloro-4-hydroxybenzyl)phenol, 4,4°-methylenebis(2,6-di-t-butylphenol), 4,4°-methylenebis(2-t-butyl-5-methylphenol), 4,4°-methylenebis(2-7-butyl-6-methylphenol), 4
．． 4'-ethylidenebis(2,6-di-t-butylphenol), 4,4°-ethylidenebis(2-t-butyl-6-methylphenol), 4,4°-propylidenebis(2,6-di-t- butylphenol), 4.4°-
Butylidene bis(2-cyclohexyl-6-methylphenol), bis(3,5-di-t-butyl-4-hydroxyphenyl)phenylmethane, bis(3,5-di-t-
-butyl-4-hydroxyphenyl)(4-methoxyphenyl)methane, bis(3,5-di-butyl-4-
Hydroxyphenyl) (4-dimethylaminophenyl)
Methane, tris(3,5-di-t-butyl-4-hydroxyphenyl)methane. An example of a combination of a reducing agent and a photopolymerization initiator in the case of adopting this embodiment is listed below. For example, as a reducing agent, 4.4°-propylidene bis(2
, 6-di-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol),
4. When using 4°-methylenebis(2,6-di-t-butylphenol) etc., 380nm to 390n
A photopolymerization initiator sensitive to , benzyl and the like are preferred. Also, 2,6-di-t-butyl-4-(2-hydroxy-
3-71butyl-5-methylbenzyl)phenol, 2
．． 6-di-t-butyl-4-benzylphenol, 2,
6-di-7-butyl-4-o-)lylmethylphenol, etc., and those that 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 Preferred are l-phenyl-2-hydroxy-2-methylpropan-I-one, l-hydroxycyclohexylphenyl ketone, benzyl dimethyl ketal, benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and the like. In addition, a reducing agent represented by the following formula (TI), l [In formula (II), R and R' may each be the same or different and represent a hydrogen atom, an alkyl group, or a cycloalkyl group. , ", ro may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an amino group, an aryl group, an aralkyl group, an alkoxyl group, and R" represents a hydrogen atom, an alkyl group, an aryl group. represents a group. ] is 400~ by redox reaction with organic silver salt.
In order to generate a compound (light-absorbing compound) having a large absorption at 500 nm, a polymerized image with a large contrast can be formed by using a photopolymerization initiator having sensitivity at 400 to 500 nm. In the general formula HI), the halogen atom is a fluorine atom, chlorine atom, bromine atom, or iodine atom, and the alkyl group is a substituted or unsubstituted linear or branched alkyl group having 1 to 18 carbon atoms. For example, methyl, ethyl, propyl, i-propyl, butyl, t-butyl, i
- Straight chain or branched hydrocarbon groups such as butyl, amyl, i-amyl, 5ec-amyl, thexyl, hexyl, hebutyl, octyl, nonyl, dodecyl, stearyl, methoxyethyl, ethoxymethyl, ethoxyethyl, ethoxypropyl , ethoxybutyl, propoxybutyl, i-
Linear or branched alkoxyalkyl groups such as propoxypentyl, t-butoxyethyl, hexyloxybutyl, hydroxyalkyl groups such as hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, aminomethyl , dimethylaminomethyl, aminoethyl, dimethylaminoethyl, diethylaminoethyl, morpholinobutyl, piperidinoethyl, aminopropyl, diethylaminopropyl, dipropylaminoethyl, aminobutyl, morpholinobutyl, and other aminoalkyl or alkylaminoalkyl groups. The cycloalkyl group is a substituted or unsubstituted cycloalkyl group having 5 to 18 carbon atoms, such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, methylcyclohexyl, dimethylcyclohexyl,
Ethylcyclohexyl group, etc. The amine group is a substituted or unsubstituted amino group, such as amine, acetylamino, methylamino, dimethylamino, diethylamino, pyrrolidino, morpholino, benzenesulfonamide, toluenesulfonamide, dipropylamino, dibutylamino group, etc. . The aryl group is a substituted or unsubstituted aryl group having 6 to 16 carbon atoms, such as phenyl, naphthyl, anthryl, phenanthryl, tolyl, xylyl, cumenyl, mesityl, chlorophenyl, methoxyphenyl, fluorophenyl, and the like. The alkoxyl group has 1 to 18 carbon atoms,
Preferred are methoxy, ethoxy, propoxy, i-propoxy, butoxy groups and the like. The aralkyl group is substituted or unsubstituted and has 7 to 19 carbon atoms, such as benzyl, phenethyl, benzhydryl, trityl, phenylpropyl, naphthylmethyl, chlorobenzyl, dichlorobenzyl, methoxybenzyl, methylbenzyl group, etc. . Specific examples of compounds represented by general formula (II) having the above substituent include 4.4°-methylenebis(2-
methyl-1-naphthol), 4.4"-methylenebis(
2-ethyl-1-naphthol), 4,4°-methylenebis(2-t-butyl-l-naphthol), 4,4'-
Methylenebis(2-cyclohexyl-1-naphthol)
, 4.4°-methylenebis(2-t-butyl-6-methyl-1-naphthol), 4,4°-methylenebis(2,
6-diethyl-l-naphthol), 4.4'-methylenebis(2-benzyl-1-naphthol), 4,4°-methylenebis(2-t-butyl-8-methyl-1-naphthol), 4.4 “-methylenebis(2-methyl-5-chloro-1-naphthol), 4,4°-methylenebis(2-methyl-5-chloro-1-naphthol),
-methyl-8-dimethylamino-1-naphthol), 4
,4°-methylenebis(2-methyl-5-benzyl-1
-naphthol)4.4°-methylenebis(2-methyl-
5-methoxy-l-naphthol), 4,4°-methylenebis(2-methyl-5-phenyl-1-naphthol)
4-(3'-t-butyl-4'-hydroxynaphthyl)
Methyl-2-methyl-1-naphthol, 4-(3°-
Cyclohexyl-4°-hydroxynaphthyl)methyl-
2-methyl-1-naphthol, 4.4°-benzylidenebis(2-methyl-1-naphthol), 4,4°-benzylidenebis(2-t-butyl-1-naphthol),
4.4'-ethylidenebis(2-methyl-1-naphthol), 4,4°-ethylidenebis(2-t-butyl-1
-naphthol), bis(4-hydroxy-3-methylnaphthyl)tolylmethane, etc. The light-absorbing compound may or may not be within the scope 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-
Trimethylbenzoyldiphenylphosphineoxide, benzyl, etc. can be used. Also, 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, etc. or those that form cyan dyes with secondary color developing agents have 300~
A photoinitiator sensitive to 340 nm, for example 1-
Phenyl-2-hydroxy-2-methylpropane-1-
on, l-hydroxycyclohexylphenyl ketone,
Benzoin dimethyl ether, benzophenone, 4-benzoyl-4"-methyldiphenyl sulfide, etc. can be used. As the polymerizable polymer precursor contained in the photosensitive layer,
Compounds having at least one reactive vinyl group in the molecule can be used, such as one or more selected from the group consisting of reactive vinyl group-containing monomers, reactive vinyl 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 polymer precursors 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, ether methacrylate, propyl methacrylate, butyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate, vinylpyridine,
N-vinylpyrrolidone, N-vinylimidazole, 2-
Monovalent monomers such as vinyl imidazole, N-methyl-2-vinylimidazole, propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, phenyl vinyl ether, p-methylphenyl vinyl ether, p-chlorophenyl vinyl ether; For example, divinylbenzene, distyryl oxalate, distyryl malonate, distyryl succinate, distyryl glutarate, distyryl adipate, distyryl maleate, distyryl fumarate, β, β-distyryl dimethylglutarate, distyryl 2-bromoglutarate, α. α゛-Distyryl dichloroglutarate, distyryl terephthalate, di(ethyl acrylate) oxalate, di(methyl ethyl acrylate), di(ethyl acrylate) malonate, di(methyl ethyl acrylate) malonate, di(ethyl succinate) acrylate), glutaric acid di(ethyl acrylate), adipate di(ethyl acrylate), maleic acid di(diethyl acrylate)
, fumaric acid di(ethyl acrylate), β. β-dimethylglutaric acid di(ethyl acrylate), ethylene diacrylamide, propylene diacrylamide, 1.4-phenylene diacrylamide, 1.4-phenylene bis(oxyethyl acrylate), 1.4-
Phenylene bis(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(7acryloyloxyethoxycarbamoylcyclohexyl)methane, oxalate di(ethyl methacrylate), oxalate di(methylethyl methacrylate), Malonic acid di(ethyl methacrylate), malonic acid di(methyl ethyl methacrylate),
Succinic acid di(ethyl methacrylate), succinic acid di(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 Acid di(methyl ethyl methacrylate), β, β′ dimethyl glutarate di(
ethyl methacrylate), 1,4-phenylene bis(
divalent monomers such as 1,4-bis(methacryloyloxyethoxy)cyclohexane acryloyloxyethoxyethyl vinyl ether; e.g. pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tri(hydroxystyrene), cyanuric Acid triacrylate, cyanuric acid trimethacrylate, 1.
l, 1-trimethylolpropane triacrylate, 1,1,1. -trimethylolpropane trimethacrylate, cyanuric acid tri(ethyl acrylate'),
1,1.1-trimethylolpropane tri(ethyl acrylate), cyanuric acid tri(ethyl vinyl ether)
, a condensate of 1,1.1-trimethylolpropane tri(toluene diisocyanate) and hydroxyethyl acrylate, a condensate of 1.1.1-trimethylolpropane tri(hexane diisocyanate) and p-hydroxystyrene, etc. monomers; for example, tetravalent monomers such as ethylene tetraacrylamide and propylene tetraacrylamide, and also those that leave a reactive vinyl group at the end of the oligomer or polymer or react with the side chain of the oligomer or polymer. Polymerizable polymer precursors include those with a vinyl group attached thereto. Examples of the photopolymerization initiator contained in the photosensitive layer 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 4,4°-dimethoxybenzophenone; acetophenones such as acetophenone and 4°-methoxyacetophenone; benzoin alkyl ethers; Chalcones and styryl ketones having a dialkylamino group; 3.
3°-carbonylbis(7-medoxycoumarin), 3.
3°-Carbonylbis(7-dinithylaminocoumarin)
Examples include coumarins such as. 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 photopolymerization initiators include trivalent iron ion compounds (e.g. ferric ammonium citrate) combined with peroxides, photoreducible dyes such as boflavin and methylene blue and triethanolamine,
Examples include those using a combination of a reducing agent such as ascorbic acid. 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 chalcone, styryl ketones, or coumarins having a dialkylamino group, and s-triazine or camphorquinone having a trihalomethyl group. In addition to these photosensitive silver salts, reducing agents, polymerizable polymer precursors, and photopolymerization initiators, the photosensitive layer also contains binders, color toners, antifoggants, photodiscoloration inhibitors, solid solvents, and surfactants as necessary. agent, antistatic agent, etc. can be added. Examples of the thermally diffusible substance 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. etc. can be mentioned. In general, the lower the molecular weight of a thermally diffusible substance, the higher the thermal diffusivity, and for example, a dye having many polar groups such as a carboxyl group, an amino group, a hydroxyl group, a nitro group, and a sulfone group has a lower thermal diffusivity. Therefore, depending on the polymerization, crosslinking density, heating conditions, etc. in the photoreceptor of the present invention, a dye having desired thermal diffusivity may be appropriately selected based on molecular weight and functional group. Furthermore, as a color developer in the image-receiving layer for reacting with a heat-diffusible substance to exhibit a color, zinc oxide, calcium sulfate, novolak type resin, zinc 3,5-dimethyl-t-butylsalicylate, etc. can be used. . As the polymerizable polymer precursor and photopolymerization initiator contained in the polymerization layer of the present invention, those used in the photosensitive layer can be used. In the present invention, the same photopolymerization initiator as used in the photosensitive layer and the polymerization layer may be used, or any initiator having an overlapping absorption wavelength range may be used. Each layer of the photoreceptor of the present invention can be formed by dissolving the above-mentioned essential components in a solvent together with an appropriately used binder, coating and drying the solution on a support such as metal, plastic, or paper, or by using the binder itself to maintain strength. In the case of dripping, the above-mentioned essential components can be contained in a film or sheet-like product formed from a binder without using the above-mentioned support. Note that the shape of the photoreceptor of the present invention is not particularly limited, such as a flat plate, a cylindrical shape, a roll shape, and the like. Both the photosensitive layer and the polymer layer of the photoreceptor of the present invention preferably contain 0
．． The film is formed to a thickness of about 1 gm to 2 mm, preferably about Igm to 0.1 mm. 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 butylade, polyvinyl acecool. , polyvinyl alcohol, polyvinylpyrrolidone; copolymer resins such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer; e.g. polymethyl methacrylate, Methyl 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°-phenylene dicarbonate), poly(4,4°-isopropylidene Phenylene carbonate coater terephthalate)
, poly(4,4°-isopropylidene diphenylene carbonate), poly(4,4°-5ec-butylidene diphenylene carbonate), poly(4,4′-isopropylidene diphenylene carbonate block oxyethylene), etc. polyacrylate resins; polyamides;
Examples include polyimides; epoxy resins; phenolic resins; polyolefins such as polyethylene, polypropylene, and chlorinated polyethylene; and natural polymers such as gelatin. A preferred blending ratio of the above components in the photosensitive layer of the photoreceptor of the present invention is as follows. Preferably 0 silver halide per mol of organic silver salt
．． 001 mol to 2 mol, more preferably 0.05 mol to
It is desirable to contain 0.4 mol. In addition, organic silver salt 1
The reducing agent is preferably 0.2 to 3 moles per mole,
More preferably, the content is 0.7 mol to 1.3 mol. The polymerizable polymer precursor is preferably 10 to 1000 parts by weight, more preferably 20 to 1000 parts by weight, per 100 parts by weight of the organic silver salt.
It is preferable to contain 500 parts by weight. The photopolymerization initiator is 0.1 to 30 parts by weight per 100 parts by weight of the polymerizable polymer precursor.
Parts by weight, more preferably 0.5 to 10 parts by weight, are used. For the polymerization layer, the photopolymerization initiator is preferably used 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 polymer precursor. 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 100 parts by weight of the polymerizable polymer, photopolymerization initiator, and appropriately contained binder. Parts by weight. Incidentally, it is preferable that the polymer layer and the photosensitive layer in the photoreceptor are directly laminated. Further, the polymer layer of the photoreceptor in the present invention has a two-layer structure of a coloring material layer made of a heat-diffusive substance and a binder, and a polymer layer made of a polymerizable polymer precursor and a photopolymerization initiator, and has a three-layer structure as a whole. Next, the image forming method of the present invention will be described. A method of forming an image using the photoreceptor of the present invention includes the following steps. The photoreceptor of the present invention is subjected to (a) imagewise exposure and (b) heating to produce or generate a compound that absorbs light in the absorption wavelength range of the photopolymerization initiator contained in the polymer layer and the photosensitive layer. (C) a process of polymerizing the polymerizable polymer precursor in the polymerization layer and the photosensitive layer according to the distribution of the light-absorbing compound by performing full-surface exposure to form a polymerized latent image; d) The photosensitive layer and the image receptor are laminated and heated, thereby transferring the thermally diffusive substance in the polymerized layer to the image receptor side in accordance with the polymerized latent image formed in the above process. image forming method. When the image receptors are stacked and heated, it is preferable to perform the heating under the conditions of the following formula (B). T g+ <'I' t, □≦Tgz・・・・・・・
(B) (In the formula, Ttr□□ represents the transfer temperature of the photoreceptor.) In the method of the present invention including the above-mentioned steps, since silver halide is used, latent image writing sensitivity is excellent, and the polymer Since the formation method is full exposure, it takes only a short time, and the processing time in each process from image writing to development can be efficiently shortened. Moreover, 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, depending on the difference in thermal diffusivity of the thermal diffusive substance caused by the degree of crosslinking between the polymerized latent image of the polymerized layer and the unpolymerized area, the thermal diffusive substance can be selectively applied to image-receiving paper, etc. Since the silver image formed during the amplification process and the color image are separated, the resulting color image is free from turbidity and has excellent saturation and brightness. Furthermore, due to the difference in the degree of polymerization and crosslinking, It is now possible to obtain high-resolution density gradations that were previously unavailable. The mechanism of thermal diffusion of the above-mentioned thermally diffusive substance is that the transferred heat By heating above the diffusion temperature (Tdlffug*) peculiar to the diffusive substance, that is, T trans ≧ T
Transcription is performed by establishing the drffuma relationship. In the present invention, a clear image without color cast can be transferred depending on the degree of suppression of the diffusivity of the diffusible substance in the polymerized portion and the unpolymerized portion. Therefore, in the present invention, the heating of the medium during transfer is determined by the following formula (B): Tgl<Ttr, n
, ≦Tgz''...(B). Figure 2 shows the changes in optical density (0, D,) for the polymerized area (curve a) and the unpolymerized area (curve b). An illustrative graph is shown. As shown in the figure, transcription does not occur when T t r a.1 is below T g +, and conversely, when T ' t r a
If it is higher than 2, the thermally diffusive substance in the polymerized portion will also be transferred, resulting in color cast, which is not preferable. In addition, since the same distribution of polymer latent images as in the polymerized layer is formed in the photosensitive layer, even if the effect of suppressing the thermally diffusive substance in the polymerized portion is insufficient, the distribution of the polymer latent image in the photosensitive layer above the polymerized portion may be insufficient. The polymerized portion can suppress thermal diffusivity, and the thermally diffusive substance in the polymerized portion is diffused and transferred, which has the effect of reducing color fog. Next, an outline of each process included in the method of the present invention will be explained with reference to the drawings. The process (a) above is a process of writing an image with light, and as shown in FIG. 3, a desired image is written on the photosensitive layer 1 of the present invention formed on the base material 3 by image exposure or digital exposure. to expose. As a result, silver nuclei 5 are generated on the photosensitive silver halide in the exposed area 1-a, forming a latent image. The generated silver nuclei 5 serve as a catalyst for the thermal reaction between the organic silver salt contained in the photosensitive layer 1 and the reducing agent. The exposure conditions for writing this latent image are determined according to the concentration of silver halide contained in the photoreceptor, etc., so that the desired characteristics such as sufficient contrast can be obtained in the obtained polymerized latent image. They may be selected and used 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 layer 1 on which the latent image has been formed is heated, the silver nuclei 5 selectively act as a catalyst in the exposed area 1-a, as shown in FIG. The salt and the reducing agent react, and the organic silver salt is reduced to silver atoms 1O, and at the same time, the reducing agent becomes the oxidant 11. The heating in the step (b) cannot be generalized depending on the composition of the photosensitive layer, etc., but it is heated from 60°C to 200°C, more preferably from 70°C to 150°C for 1 second to 5 minutes, more preferably 3 minutes. Heat treatment may be performed for 60 seconds to 60 seconds. - For boat fishing, high temperatures require a short heating time, while low temperatures require long heating. 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 the support, a method of heating by irradiation with laser light, etc. can be used. Subsequently, as shown in FIG. 5, in the step (c) above, the entire surface is exposed from the photosensitive layer 1 side to cleave the photopolymerization initiator contained in the photosensitive layer 1 and polymerization layer 2, and to generate radical species. to occur. A polymerization reaction occurs due to these radical species, and a portion of the polymer is formed in the photosensitive layer 1 and the polymer layer 2. At that time, in the photosensitive layer 1, metal silver 10 and/or oxidant 1
1 absorbs light, and in the polymerization layer 2, the amount of light transmitted differs accordingly, so the exposed area 1-a and the unexposed area 1-b absorb light in the wavelength range that the photopolymerization initiator absorbs. Since the amount of transmission is different, there is a difference in the polymer formation state between the exposed area 1-a and the unexposed area 1-b, and a polymerized latent image is formed due to this difference. As the light source used in the above steps (a) and (C), for example, sunlight, tungsten lamp, mercury lamp, halogen lamp, xenon lamp, fluorescent lamp, LED, laser beam, etc. can be used, and the wavelength of the light used in these processes is the same. may be different. Incidentally, even if light of the same wavelength is used in steps (a) and (C), silver halide usually has a sufficiently higher photosensitivity than the photoinitiator, so photopolymerization does not occur in step (a). A sufficient latent image can be written with light of a moderate intensity. A sensitizing dye may be added at the time of forming the photosensitive layer depending on the color distribution of each light source. Furthermore, in the step (c) above, a means for heating the photoreceptor during exposure may be used. Even if this is reheated, the above (b)
) may be used to utilize residual heat from the process. Next, in the process of thermal diffusion transfer in color image formation, as shown in FIG. A thermally diffusive substance 4 is present, and the thermally diffusive substance 4 corresponding to the polymerized portion 2-B in the polymerized layer 2 has a higher heat content than the thermally diffusive substance 4 corresponding to the unpolymerized portion 2-A. Since the diffusivity is suppressed in the polymer layer 2, the heat diffusible substance 4 in the unpolymerized portion 2-A is selectively diffused and transferred by the heating. The diffusivity of the thermally diffusible substance 4 in the polymerization region 2-H is suppressed by polymerization of the polymerizable polymer precursor, or by crosslinking of the polyfunctional polymer precursor when it is contained. This is because even if the polymerization part 2-B is heated, the molecular chains of the polymer are not easily relaxed, and the diffusion of the thermally diffusible substance is suppressed. Further, even if the thermally diffusive substance in the polymerized portion of the polymerized layer 2 is diffused more than necessary, it is suppressed by the polymerized portion of the photosensitive layer 1, so that color fogging is unlikely to occur. The image receiving layer of the image receptor used in this process is not particularly limited as long as it can diffusely transfer the thermally diffusive substance and form a good image, such as polyester resin, polycarbonate resin, polyvinyl acetate resin. Various materials can be used, such as polyurethane resin, polyamide resin, polycaprolactam resin, polyvinyl chloride resin, etc. The heating temperature in this process is preferably 70 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 polymer5. be. After the above process, if the photoreceptor is removed by peeling or the like, an image consisting of the transferred dye or the dye 8 developed in the image-receiving layer can be obtained in the image-receiving layer 7, as shown in FIG. can. This image is an image with excellent contrast, and has excellent brightness and chroma. Next, an example of a method of obtaining a multicolor image by subtractive color mixing in the method of the present invention will be described. First, as shown in FIG. 8, a polymeric layer 2-1.2 containing yellow, magenta, and cyan heat diffusive substances, respectively.
-2.2-3 is formed on a film-like or sheet-like substrate 3, and a photoreceptor Hl is further formed on the photoreceptor 12.
get. Next, as shown in FIG. 9, this photoreceptor 12 is exposed to the image exposure device 18, the thermal development device 19, and the entire surface in order of the yellow polymerization layer 2-1, the magenta polymerization layer 2-2, and the cyan polymerization layer 2-3. The film is passed through an exposure device 20, and under appropriate conditions, a latent image is formed by silver nuclei, amplified into a latent image by a reducing agent and an oxidant, and converted into a polymer latent image by full-surface exposure.
Finally, the image-receiving layer 7 of the image-receiving paper and the photosensitive layer are sequentially brought into contact with each other, and yellow 22, magenta 23, and cyan 24 are passed through the thermal transfer device 21 according to the polymer latent image. The image receiving layer 7 includes a first
A multicolored image as shown in Figure 0 is formed. In addition, in the case of forming a multicolor image, in addition to using a photoreceptor in which polymerized layers each containing yellow, magenta, and cyan heat diffusive substances are arranged on the same substrate as described above, By using three types of monochromatic photoreceptors in which the three types of polymerized layers described above are provided on different substrates, and repeating the image exposure, heating, full-surface exposure, and transfer in the same manner for each photoreceptor, Can form multicolored images. In addition, a black layer may be further provided as necessary.
Further, multiple polymer layers may be laminated as necessary. [Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples. Sei No. 11 fresh (thermal diffusible dye) MS Magenta vP (manufactured by Mitsui Toatsu Dyes ■) 2.5 parts (photopolymerization initiator) 2.4-diethylthioxanthone 1.5 parts Ethyl dimethylaminobenzoate 1 part (polymerization Polymer precursor) Trimethylolpropane triacrylate 10 parts (binder) Polymethyl methacrylate 1 part (solvent) Methyl ethyl ketone 75 parts The above formulation was weighed out and thoroughly dissolved using an ultrasonic disperser to obtain Solution A. Liquid A was coated onto a 2 μm thick polyester film that had been subjected to anchor treatment so that the dry film thickness was 4 to 5 μm to form a polymerized layer. Behenic acid 4 parts Phthalazinone 1.5 parts AgBr
1.2 parts silver henate
7 parts polyvinyl butyral 10 parts pentaerythritol tetraacrylate 4 parts 4.4'-methylenebis(2,6 di-tert-butylphenol) 5 parts 2.4-diethylthioxanthone 015 parts ethyl dimethylaminobenzoate 0.4 parts toluene/butanol
120 parts of the above formulation was weighed out and sufficiently dissolved and mixed using a paint shaker to obtain Solution B. On the substrate provided with the polymer layer, apply liquid B to a dry film thickness of 5 to 6 μm.
A photosensitive layer was prepared by coating the photosensitive layer so as to give a thickness of m. The thus prepared photoreceptor of the present invention was fitted with a lithium film, and a fluorescent lamp having a fluorescence peak at 340 nm was irradiated for 2 seconds from a distance of 5 cm to perform image exposure. Remove the lith film and use a heat developing machine at 120℃ for 20s.
EC was passed through the photoreceptor. Furthermore, it was placed on a hot plate heated to 60° C., and a fluorescent lamp having a fluorescence peak at 390 nm was irradiated for 40 seconds from a distance of 1 cm. An image-receiving paper prepared by coating a polyester resin as an image-receiving layer on a synthetic paper in advance and a photosensitive layer are stacked in direct contact with each other.
The dye was diffused and transferred from the polymerization layer to the image receiving layer by heating from the photoreceptor side under conditions of 20 seconds at .degree. C., and a clear red image corresponding to the unexposed area of the image was obtained on the image receiving paper. Note that all of the above treatments were performed in a dark room. The O and D values of the exposed portion of the image were 1.10, and the O and D values of the unexposed portion of the image were 0.02. In addition, when we took out the completely polymerized part and the unpolymerized part of this latent image and measured the Tg of each part using the viscoelastic measurement method, the Tgz of the polymerized part of the polymerized layer was 135°C, and the Tg of the unpolymerized part was 135°C. r was 60°C. Coating liquid A was applied onto the polyester film in the same manner as in Example 1.
was applied so that the dry film thickness was 4 to 5 μm. Pentaerythritol tetraacrylate, 2,4-diethylthioxanthone, and ethyl dimethylaminobenzoate were removed from Coating Solution B in Example 1 to prepare Coating Solution C, which was applied onto the polymerized layer until the dry film thickness was 5. A photoreceptor of Comparative Example 1 was prepared by coating the film to a thickness of 6 μm to form a photosensitive layer. In the same manner as in Example 1, a red image was formed on the image-receiving paper by performing image exposure, heating, full-surface exposure, and heat transfer steps, and a red image was formed in the image-exposed area, and the ○, D, and value of the image-exposed area were is 1.21, and the value of ○, D, in the unexposed area of the image is 0.15.
Met. Although contrast was formed in the image, there was color fog. [Effects of the Invention] As explained above, according to the photoreceptor and image forming method of the present invention, a photoconductor with high sensitivity, high resolution, good contrast through dry processing, no color fog, and excellent brightness and chroma can be obtained. Color images can be obtained.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the optical density and transfer temperature during thermal transfer of the thermally diffusive substance contained in the image forming medium of the present invention, and FIG. 2 is a graph showing the relationship between the transfer temperature and the transfer temperature in the method of the present invention. It is a graph showing the relationship between the glass transition point of a polymerized part and an unpolymerized part in a polymerized layer. FIGS. 3 to 7 are schematic cross-sectional views showing aspects of each process of the color image forming method of the present invention, and FIGS. 8 to 10 are schematic cross-sectional views showing an example of a method for obtaining a multicolor image. be. 1... Photosensitive layer 1-b... Unexposed area 2-A... Unpolymerized area 3... Base material 5... Silver core 7... Image receiving layer 9... Image receptor 11. ...Oxidant 1-a...Exposed part 2...Polymerized layer 2-B...Polymerized part 4...Thermodiffusible dye 6...Substrate of image receiving paper 8...Transfer dye 10. ...Silver atom 12...Photoreceptor

Claims (1)

[Scope of Claims] 1. A polymer layer containing at least a polymerizable polymer precursor, a photopolymerization initiator, and a heat-diffusive substance on a base material, and at least a photosensitive silver halide, an organic silver salt, and a polymer layer containing at least a photosensitive silver halide, an organic silver salt, and A light-absorbing compound that absorbs light in the absorption wavelength range of the photopolymerization initiator, which is generated or disappears through the process of image exposure and thermal development, a polymerizable polymer precursor, and a photopolymerization initiator contained in the polymerization layer. A photoreceptor comprising a photosensitive layer containing a photopolymerization initiator having an absorption wavelength range that is the same as or near the absorption wavelength range of the agent. 2. The photoreceptor according to claim 1, wherein a polymerized part and an unpolymerized part satisfying the following formula (A) are formed in the polymerized layer. Tg_2-Tg_1≧30°C...(A) (wherein, Tg_1 is the glass transition temperature of the unpolymerized part, Tg_2
represents the glass transition temperature of the polymerized portion. )3, Claim 1
Or, by (a) imagewise exposing the photoreceptor described in 2 and (b) heating, a compound that absorbs light in the absorption wavelength range of the photopolymerization initiator contained in the polymerization layer and the photosensitive layer is produced. (c) a process of polymerizing the polymerizable polymer precursor in the polymerization layer and the photosensitive layer according to the distribution of the light-absorbing compound by performing full-surface exposure to form a polymerized latent image; (d) The photosensitive layer and the image receptor are laminated and heated, thereby transferring the thermally diffusive substance in the polymerized layer to the image receptor side in accordance with the polymerized latent image formed in the above process. An image forming method. 4. The image forming method according to claim 3, wherein the heating in the step (d) is performed so as to satisfy the following formula. Tg_1≦Ttrans<Tg_2・・・・・・(B
) (In the formula, Ttrans indicates the transfer temperature of the photoreceptor.)