JPH0215056B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a photosensitive layer on a pre-colored dye- or pigment-containing mask layer, and after imagewise exposure to this photosensitive layer, the surface is water-treated to form a high-contrast image. Regarding forming materials. Conventionally, among the non-silver salt photosensitive materials used as lithographic printing originals, types using photosensitive resin layers containing dyes and pigments are disclosed in JP-A-52-62427 and JP-A-52-62427.
Some of these are disclosed in Publication No. 52-2520 and the like. In this method, in an attempt to obtain a high-density image,
If the amount of dye or pigment in the photosensitive resin layer is increased, the dye or pigment will absorb actinic rays that promote sensitization of the photosensitive resin, resulting in a decrease in sensitivity. Further, as a type in which a relief image is formed with a photosensitive resin layer and/or is dyed after the relief image is formed, there are those disclosed in Japanese Patent Application Laid-open Nos. 49-22929 and 49-22930. This method requires a special dye bath treatment containing the dye, and dyeing conditions must be carefully controlled to achieve the appropriate density. In addition, as a type in which a mask layer is provided in advance and a photosensitive resin layer is provided on the mask layer, Japanese Patent Application Laid-Open No. 48-65927
No. 50-139720. This method uses a metallic mask layer, and after imagewise exposure, the etching of the metallic layer to form an image requires a special acid or alkali. It is undesirable because it causes problems in terms of liquid stability, pollution, and occupational health. On the other hand, Japanese Patent Application Laid-Open Nos. 47-16124 and 52-89916 disclose a method of providing a photosensitive resin layer on a mask layer in which a dye or pigment is mixed or dispersed in a polymer binder. This method still requires a specific organic solvent or alkali to develop the photosensitive layer, which is undesirable because it poses pollution and occupational health problems. Therefore, the present inventors first developed a water-developable image forming material having a photosensitive layer containing a water-softening polymer compound in Japanese Patent Application No. 56-119332 (Japanese Unexamined Patent Application Publication No. 58-1989).
37638), etc. The inventors of the present invention continued their research on this image forming material and found that it has the disadvantage that it takes a long time to develop. Based on the above facts, the present inventors have conducted extensive research and have discovered that by using a water-insoluble particulate dispersion in the photosensitive layer, it is possible to develop with water and in a very short time. This has led to the present invention. That is, the object of the present invention is to have a photosensitive layer that can be developed in a short time with water, has high film strength, has excellent film forming ability, has few pinholes, and has a high density. An object of the present invention is to provide an image forming material that can stably obtain high contrast images. The object of the present invention is to mutually dissolve (a) a colored mask layer, (b) an ethylenically unsaturated compound, a photopolymerization initiator, and a water-insoluble particulate dispersion on a support from the side close to the support. A water-developable image forming material having a layer formed by coating a dispersed photosensitive composition, wherein the colored mask layer contains a water-softening polymer compound, and the water-insoluble particulate dispersion is This can be achieved by using an image-forming material that is a latex-like polymer compound that is a copolymer with a monomer having a polar group in its main chain or side chain and is intermolecularly cross-linked within the particles. The present invention will be explained below. First, a water-insoluble particulate dispersion (hereinafter referred to as a particulate dispersion) among the components of the present invention will be explained. The particulate dispersion of the present invention is a dispersion that is water-insoluble and can remain stable for several hours or more without dissolving, aggregating, or settling in a desired solvent. The particulate dispersion useful in the present invention is not particularly limited in type as long as it does not dissolve, agglomerate or precipitate in the desired solvent. Further, these particulate dispersions may be used alone or in combination of two or more. Examples of such particulate dispersions include polyacrylic esters or copolymers thereof, polyacrylonitrile or copolymers thereof, polystyrene or copolymers thereof, polyethylene or copolymers thereof, polyvinyl chloride or copolymers thereof, polyvinylidene chloride or copolymers thereof, Latex-like polymeric compounds such as polyvinyl acetate or a copolymer thereof, resol resin or a copolymer thereof, ionomer resin, polymethyl methacrylate or a copolymer thereof, polybutadiene or a copolymer thereof can be mentioned. Further, the latex-like polymer compound used in the present invention is a copolymer with a monomer having a polar group in the main chain or side chain. Preferred polar groups include -COOR,

【formula】 【formula】

【formula】

【formula】

[Formula] ―SO ₃ R, ―NO ₂ ,

【formula】

[Formula] -CN, -Cl, -Br, -I, -F,

【formula】

[Formula] (In the above general formula, R represents a hydrogen atom, an alkyl group, or a carbocyclic group.)
etc. Particularly preferred are copolymers with monomers having a quaternary nitrogen atom or a quaternary phosphorus atom. Among these, a typical example containing a quaternary nitrogen atom in the main chain is the general formula [X: anion R: alkyl group or carbocyclic group n: integer] There are monomer units of the so-called ionene type represented by [X: anion R: alkyl group or carbocyclic group n: integer] Those containing methacryloxyalkylammonium monomer units represented by the following, and those containing the general formula [X: Anion R: Alkyl group or carbocyclic group] Those containing a vinylbenzylammonium monomer unit represented by the following formula, and those in which this benzylammonium monomer unit is further bonded via an amide group are disclosed in JP-A-55 -The following general formula described in Publication No. 22766 [X: anion R: alkyl group or carbocyclic group] On the other hand, an example of a monomer unit containing a quaternary phosphorus atom in the main chain is the following general formula [X: anion R, R': alkyl group or carbocyclic group] Examples of the side chain include the following general formula: [X: Anion R: Alkyl group or carbocyclic group] Examples include those represented by the following. In each of the above general formulas ~, specific examples of the anion represented by X include halogen ion, sulfate ion, phosphate ion, sulfonate ion, acetate ion, etc.
As the alkyl group represented by R′, for example,
Examples include methyl, ethyl, propyl, isobutyl, pentyl, hexyl, heptyl, decyl and other groups, and examples of carbocyclic groups include aryl, aralkyl, cycloalkyl, such as benzyl, phenyl, p-methylbenzyl. , cyclohexyl, cyclopentyl and the like. In each of the above general formulas, the alkyl group or carbocyclic group represented by R bonded to N or P may be the same or different. These latex-like polymer compounds can be obtained by emulsion polymerization. It can also be obtained by later converting the synthesized polymer into a latex. Furthermore, in order to enable the use of oil-soluble ethylenically unsaturated compounds and photopolymerization initiators, it is desirable that these latexes be dispersed in an organic solvent. Furthermore, these latexes used in the present invention are intermolecularly crosslinked within the particles to increase stability against organic solvents. That is, in a preferred embodiment, the particulate dispersion is polyacrylic acid ester or a copolymer thereof, polystyrene or a copolymer thereof, polyethylene or a copolymer thereof, polyvinyl chloride or a copolymer thereof, polyvinylidene chloride or a copolymer thereof, polyvinyl acetate or a copolymer thereof. These latexes are preferably copolymers with a monomer having a polar group represented by the following general formula [-COOR,

【formula】

【formula】

【formula】

【formula】

【formula】 【formula】

【formula】

【formula】

[Formula] -CN, -SO ₃ R, -NO ₂ , -Cl, -Br, -I, -F (In the above general formula, R represents a hydrogen atom, an alkyl group, or a carbocyclic group.) More preferred These latexes have a quaternary nitrogen atom or a quaternary phosphorus atom in the main chain or side chain, more preferably intermolecular crosslinking within the particles, and particularly preferably an organic solvent is used as a dispersion medium. be. The particle size of these particulate dispersions used in the present invention is preferably in the range of 10 mμ to 1μ. If the particle size is larger than 1μ, the resolution of the final image will be poor, and if the particle size is smaller than 10mμ, it is practically difficult to adjust. The ethylenically unsaturated compound of the present invention is a monomer,
It includes prepolymers, ie, dimers, trimers, tetramers, oligomers (polymer or polycondensate having a molecular weight of 10,000 or less), mixtures thereof, copolymers thereof, and the like. Suitable ethylenically unsaturated compounds used in the present invention include acrylic esters and methacrylic esters of polyhydric alcohols, such as ethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, trimethylolpropane, pentaerythritol, Examples include acrylic acid and methacrylic acid esters such as neopentyl glycol. Acrylic acid or methacrylic acid ester modified from bisphenol A, such as a reaction product of bisphenol A-epichlorohydrin epoxy resin prepolymer and acrylic acid or methacrylic acid, an alkylene oxide adduct of bisphenol A, or its hydrogen Additives such as acrylic acid and methacrylic esters may also be used. Apart from these esters, methylene bis-acrylamide, methylene bis-methacrylamide, and bis-acrylic or bis-methacrylamide of diamines such as ethylene diamine, propylene diamine, butylene diamine, and pentamethylene diamine are also useful. Also suitable are reaction products of diol monoacrylates or diol monomethacrylates with diisocyanates, triacrylic formals or triallylcyanurates, and the like. Apart from these monomeric compounds, linear polymeric compounds containing acryloyloxy or methacryloyloxy groups in their side chains, such as ring-opened copolymers of glycidyl methacrylate, acrylic acids of vinyl copolymers of glycidyl methacrylate, etc. , methacrylic acid addition reaction products, etc. can also be used. Although water-soluble compounds can be used as the ethylenically unsaturated compounds of the present invention, water-insoluble compounds are preferred from the viewpoint of photosensitivity and water resistance of images. Particularly from the viewpoint of photosensitivity, pentaerythritol tetraacrylate and trimethylolpropane triacrylate are preferred monomers and can be used. The photopolymerization initiator used in the present invention is generally known and effective for use in combination with ethylenically unsaturated compounds, and includes, but is not limited to, the following compounds. Specific examples include acyloin; acyloin derivatives such as benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether; decyl bromide, decyl chloride, decylamine, etc.; ketones such as benzophenone, acetophenone, benzyl and benzoylcyclobutanone; Michler's ketone, diethoxy acetophenone and substituted benzophenones such as halogenated aceto- and benzophenones; thioxanthone derivatives such as thioxanthone, chlorthioxanthone, isopropylthioxanthone, diisopropylthioxanthone, methylthioxanthone; quinones and benzoquinones;
Polynuclear cyclic quinones such as anthraquinone and phenanthrenequinone; chloranthraquinone, methylanthraquinone, octamethylanthraquinone,
Substituted polycyclic quinones such as naphthoquinone and diclonaphthoquinone; halogenated aliphatic, alicyclic and aromatic hydrocarbons and mixtures thereof, where halogen is chlorine, bromine, fluorine, iodine, such as mono- and polychlorobenzene, mono- and polybromobenzene, mono- and polychloroxylene,
Mono- and polybromoxylene, dichloromaleic anhydride, 1-(chloro-2-methyl)naphthalene, 2,4-dimethylbenzene morphonyl chloride,
1-Bromo-3-(m-phenoxyphenoxy)
Benzene, 2-bromoethyl methyl ether, chlorendeic anhydride and its corresponding esters, chloromethylnaphthyl chloride, chloromethylnaphthalene, bromomethylphenanthrene, di-iodomethylanthracene, hexachlorocyclopentadiene, hexachlorobenzene, octachlorocyclopentene and the like. compound, lofin dimer, and N-methyl-2-benzoylmethylene-
β-naphthothiazole, N-ethyl-2-(2-
There are heterocyclic compounds represented by (tenoyl)methylene-β-naphthothiazole. Although water-soluble ones can also be used as the photopolymerization initiator of the present invention,
Water-insoluble ones are preferred from the viewpoint of photosensitivity and water resistance. If desired, various additives such as a thermal polymerization inhibitor, a plasticizer, a development accelerator, and an adhesion improver may be added to the composition for a photopolymerizable photosensitive layer containing the particulate dispersion of the present invention. be able to. Specific examples of thermal polymerization inhibitors include paramethoxyphenol, hydroquinone, alkyl- or aryl-substituted hydroquinone, t-butylcatechol, pyrogallol, cuprous chloride, phenothiazine, chloranil, naphthylamine, β-naphthol, 2,6-di Examples include -t-butyl-p-cresol, pyridine, nitrobenzene, dinitrobenzene, p-toluidine, methylene blue, and organic acid copper (such as copper acetate). Examples of plasticizers include phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diaryl phthalate, and dimethyl glycol phthalate. , ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, glycol esters such as triethylene glycol dicaprylate, phosphoric acids such as tricresyl phosphate, triphenyl phosphate, etc. Examples include esters, aliphatic dibasic acid esters such as diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sepacate, dioctyl azelate, and dibutyl maleate, triethyl citrate, glycerin triacetyl ester, and butyl laurate. The amount of the ethylenically unsaturated compound used in the photosensitive layer containing the particulate dispersion of the present invention is preferably 20 to 90% by weight of the solid content in the composition for the photopolymerizable photosensitive layer.
40-70% by weight. Furthermore, the amount of photopolymerization initiator added is about 1.0% to about 100% by weight, preferably about 10% to about 50% by weight, based on the ethylenically unsaturated compound.
% by weight. Further, the amount of the thermal polymerization inhibitor added as necessary is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the composition for a photopolymerizable photosensitive layer. Note that the thickness of the photosensitive layer is 0.1 μm ~
7 μm, preferably 0.5 μm to 4 μm. Next, the colored mask layer of the present invention will be explained. The function of this colored mask layer is to form a colored image by being dissolved or removed by the same solvent in areas where the photosensitive layer has been dissolved and removed by the solvent. The colored image forming layer is formed by dispersing, mixing or dissolving a dye or pigment as a coloring agent in a binder. etc.), and the pigment is appropriately selected from organic pigments and inorganic pigments (such as those described in Pigment Handbook: Edited by Japan Pigment Technology Association and the above-mentioned patents). When the image-forming material of the present invention is used as an original for lithographic printing, it is particularly preferable to use carbon black as a colorant. This is because carbon black has a high covering power, so the film thickness can be reduced to obtain the same density, and image reproducibility is good. A water-softening polymer compound is used as the binder for the colored mask layer of the present invention, and the water-softening polymer compound is a compound whose Young's modulus decreases in the presence of water, and whose moisture content is 80% relative humidity. 1.5 at % (25℃)
% to 30% is preferred. Examples of preferred water-softening polymer compounds include methylcellulose, ethylcellulose, butylcellulose,
Hydroxyethyl cellulose, carboxymethyl cellulose, cyanoethyl cellulose, cellulose acetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate phthalate, hydroxypropyl methyl cellulose phthalate, hydroxypropyl methyl cellulose hexahydrophthalate, polyacrylic acid ester, polymethacrylic acid ester, polyvinyl butyral, poly Examples include methyl vinyl ketone, nylon 66, polyamide, polyvinyl methoxy acetal, polyvinyl acetate, epoxy resin, polyurethane, etc. In addition, addition polymers having carboxyl groups in their side chains, such as methacrylic acid copolymers, acrylic acid copolymers, itaconic acid copolymers, partially esterified maleic acid copolymers, maleic acid copolymers, croton There are acid copolymers, etc. Addition polymers having a hydroxyl group, carbamoyl group, or dimethylamino group in the side chain are also used, such as vinyl alcohol copolymer, vinyl aryl alcohol copolymer, methylene diethyl malonate copolymer (reduced product), maleic anhydride. Acid copolymer (ring element), acrylamide copolymer, methacrylamide copolymer, N,N-dimethylaminomethyl methacrylate copolymer, N,N-dimethylaminoethyl acrylate copolymer, N,N-dimethyl Examples include aminoethyl methacrylate copolymer. In addition to these, vinylpyrrolidone copolymers and the like are also useful. The molar ratio of carboxy groups, hydroxyl groups, carbamoyl groups, and dimethylamino groups in the above copolymer varies depending on the types of other copolymer components, and is determined within the scope of the above-mentioned definition of water softening property. Such polymer compounds may be used alone or in combination of two or more. The colorant/binder ratio of the mask layer used in the present invention can be determined by methods known to those skilled in the art, taking into account the target optical density and the water removability of the mask layer. In particular, when a water-softening polymer compound is used as the binder and a pigment is used as the colorant, the ratio of colorant/binder is desirably 1.0/2.0 or more. As the support on which the mask layer and the photosensitive layer comprising the particulate dispersion of the present invention are coated, a dimensionally stable plate-like material can be suitably used. Such supports include paper, paper laminated with plastics (eg, polyethylene, polypropylene, polystyrene, etc.), metal plates such as aluminum, zinc, copper, cellulose diacetate, cellulose triacetate,
Examples include films of plastics such as cellulose propionate, cellulose butyrate, cellulose acetate/butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, and the like. Among these supports, polyethylene terephthalate, polypropylene, polyethylene-laminated paper, or aluminum plate are preferred. The support is surface-treated if necessary. For example, aluminum plates undergo one or two treatments such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodizing treatment.
Preferably, the surface treatment is performed in combination with the above. In the case of a support having a plastic surface, the surface may be treated by one or a combination of two or more of chemical treatment, electric discharge treatment, flame treatment, ultraviolet treatment, high frequency glow discharge treatment, activated plasma treatment, etc. preferable. In the present invention, in order to improve the adhesion of the mask layer, an undercoat layer may be provided on the support. Synthetic resins suitable for the undercoat layer include acrylic acid ester resin, vinylidene chloride resin, vinylidene chloride-acrylonitrile-itaconic acid copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin,
Copolymer resin of acrylic acid amide or methacrylic acid amide derivative and alkyl ester of acrylic acid or methacrylic acid, fatty acid vinyl ester, styrene or acrylonitrile, copolyester resin of phthalic acid or isophthalic acid and glycols,
Examples include polymers or copolymers of glycidyl acrylate or glycidyl methacrylate, and gelatin is also effective as a component of the undercoat layer. In addition to the above-mentioned components, many synthetic resins are known as components for forming the undercoat layer, and methods for preparing the coating liquid and coating methods are well-known in the photographic material manufacturing industry to which the present invention belongs. Since they are technologies, they can be applied as appropriate. Generally, the above-mentioned synthetic resin is made into a solution or latex form with water or an organic solvent, and this is applied onto the above-mentioned support by a coating method such as Giesser coating, roll coating, air knife coating, or spray coating. . In addition, in order to prevent the photosensitive layer containing the particulate dispersion of the present invention from inhibiting polymerization caused by the influence of oxygen, to prevent scratches on the surface of the photosensitive layer, and to improve vacuum adhesion, the photosensitive layer may be dissolved or A swellable overcoat layer can be provided. This overcoat layer may be mechanically matted or a resin layer containing a matting agent. Matting agents include silicon dioxide, zinc oxide, titanium oxide, zirconium oxide,
Included are glass particles, alumina, starch, polymer particles (eg, particles of polymethyl methacrylate, polystyrene, phenolic resin, etc.) and matting agents described in US Pat. Nos. 2,701,245 and 2,992,101. Two or more of these can be used in combination. The resin used in the overcoat layer containing the matting agent is appropriately selected.
Specifically, for example, gum arabic, glue, gelatin, casein, celluloses (e.g., viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, etc.), starches (e.g., soluble starch, modified starch) etc.), polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether, polyvinylpyrrolidone, polyamide, etc. Two or more of these can also be used in combination. Next, a specific example of the method for manufacturing the image forming material according to the present invention will be shown. Generally, the mask layer binder is acetone, methanol, ethanol, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, β-hydroxyethyl methyl ether ( It is soluble in solvents such as methyl cellosolve), β-acetoxyethyl methyl ether, methyl cellosolve acetate, dimethylformamide, hexamethylphosphonamide, tetrahydrofuran, chlorobenzene, and triethylene glycol. Therefore, a suitable solvent is selected from the above solvents (single solvent or a mixed solvent containing two or more organic solvents) and dissolved therein to prepare a mask layer coating solution. The mask layer coating solution prepared in this way is
The viscosity is adjusted to be applicable to various conventionally known coating techniques. On the other hand, in the case of a photosensitive layer, a particulate dispersion using water or various organic solvents as a dispersion medium is diluted with water or a desired organic solvent to give an appropriate viscosity, and this is combined with an ethylenically unsaturated compound and a photopolymerization initiator. and prepare a uniform coating solution. In this case, it is desirable to use an organic solvent as the solvent in order to enable the use of an oil-soluble ethylenically unsaturated compound and an oil-soluble photopolymerization initiator. Suitable organic solvents include acetone, methanol, ethanol,
Isobutyl alcohol, n-butyl alcohol, isopropyl alcohol, n-propyl alcohol, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, β-hydroxyethyl ether (methyl cellosolve), β-acetoxyethyl ether, methyl cellosolve acetate, dimethylformamide, hexamethylphosphonamide, tetrahydrofuran , chlorobenzene, methylene chloride, chloroform, triethylene glycol, toluene, trichlene and the like. The coating solution thus prepared is applied to a support by a coating method selected from known coating methods such as whirler coating, dip coating, curtain coating, roll coating, spray coating, air knife coating, and doctor knife coating. applied on top. Next, the effects of the present invention will be described. In the image forming method using the image forming material of the present invention, the image forming material produced as described above is first imagewise exposed to actinic light. As the light source, various light sources are used, such as an ultra-high pressure mercury lamp, a tungsten lamp, a mercury lamp, a xenon lamp, a CRT light source, and a laser light source. In the photosensitive layer imagewise exposed to active light such as ultraviolet rays,
A crosslinking reaction due to photopolymerization progresses and the material becomes insoluble in water. Since the light-irradiated surface has strengthened adhesion, when the exposed image-forming material is immersed in water and developed in water,
Unexposed areas of the image are easily developed by light rubbing. At this time, the unexposed portion of the photosensitive layer and the underlying mask layer corresponding to that portion are removed, and a positive-negative film image is formed. Examples of the present invention will be described below, but the embodiments of the present invention are not limited to the following description. Example 1 A coating solution having the following composition was applied to one side of a polyethylene terephthalate film having a thickness of 100 μm so that the film thickness after drying was approximately 1.5 μm, and dried to form a colored mask layer. (a) Colored mask layer Hydroxypropyl methyl cellulose phthalate [manufactured by Shin-Etsu Chemical Co., Ltd., HP-50] 10 parts by weight carbon black [manufactured by Mitsubishi Chemical Corporation,
#50] 5 parts by weight Methyl cellosolve 100 parts by weight Methanol 100 parts By weight The following photosensitive liquid [A] of the present invention, comparative photosensitive liquids [B] and [C] were applied on this colored mask layer to a film thickness of 1.5 after drying, respectively. It was coated to a thickness of μm.

[Table] Further, an overcoat liquid having the composition shown below was applied thereto to a film thickness of approximately 2.5 μm to obtain image forming material samples (A), (B), and (C). Polyvinyl alcohol [Gohsenol GL-
05, manufactured by Nippon Gohsen Kagaku Co., Ltd.] 1 part by weight Water 9 parts by weight In the above sample (A), (a) hydroxypropyl methyl cellulose phthalate of the colored mask layer was mixed with polyvinyl alcohol (Gosenol GL-05, Nippon Gohsen Kagaku Co., Ltd.). Sample (D) was obtained with the only difference being that the sample (manufactured by ) was replaced. In addition, in the above sample (A), a 10% methyl cellosolve dispersion of the latex-like polymer compound (structural formula) of (b) photosensitive liquid [A] was added to Primal AC-61 (acrylic resin water-based emulsion manufactured by Rohm and Haas Co., Ltd.). Sample (E) was obtained with the only difference being that the solid content was replaced with 50% solids. Each sample of the above five types of image forming materials was overlapped with a halftone original and 80 cm was measured using a 3KW metal halide lamp.
The film was exposed to light for 10 seconds from a distance of , and then developed by immersing it in water at 20°C and rubbing it lightly. The results are shown in Table 1 below.

【table】

[Table] As is clear from Table 1, the image forming material according to the present invention has extremely good image properties and can be developed in a short time. Example 2 Trimethylolpropane triacrylate
5 parts by weight Diisopropylthioxanthone 1 part by weight Isoamyl dimethylaminobenzoate 1 part by weight 20 g of the above mixture was added to 30 g of a 3% aqueous solution of Emulgen 935 (manufactured by Kao Atlas) using a homogenizer (AM).
-8, manufactured by Nippon Seiki Seisakusho) at 15,000 rpm to obtain a dispersion liquid [A]. Next, a sample of the present invention was prepared in the same manner as in Example 1 except that the following was used as the photosensitive layer coating liquid. The above dispersion liquid [A] 4 parts by weight Corporene Latex L-2000 (33% aqueous dispersion of ionomer resin, manufactured by Asahi Dow) 1 part by weight water 15 parts by weight This sample of the present invention was exposed to light in the same manner as in Example 1. When developed, a clear black image was obtained.

Claims (1)

[Claims] 1. On a support, from the side close to the support, (a) a colored mask layer, (b) an ethylenically unsaturated compound, a photopolymerization initiator, and a water-insoluble particulate dispersion are mutually dissolved or disposed. A water-developable image forming material having a layer formed by coating a dispersed photosensitive composition, wherein the colored mask layer contains a water-softening polymer compound, and the water-insoluble particulate dispersion is An image forming material characterized in that it is a latex-like polymer compound which is a copolymer with a monomer having a polar group in its main chain or side chain and is intermolecularly cross-linked within the particles. 2. The image forming material according to claim 1, wherein the ethylenically unsaturated compound and the photopolymerization initiator are soluble in an organic solvent.