JPH0612444B2 - Method for producing photosensitive microcapsules - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing photosensitive microcapsules.

BACKGROUND OF THE INVENTION A light-sensitive material used in a method of forming an image by polymerizing a polymerizable compound by the action of a reducing agent in a portion where a latent image of silver halide is formed is disclosed in JP-B-45-11149.
No. 47-20741, No. 49-10697, JP-A Nos. 57-138632 and 58-169143.

The inventors of the present invention tried to improve the above-mentioned image forming method and invented a method capable of forming a high molecular compound by a dry process, and the present invention has been applied for a patent (Japanese Patent Application No. 59-
191353). This method uses a recording material (photosensitive material) in which a photosensitive layer comprising a photosensitive silver salt (silver halide), a reducing agent, a crosslinkable compound (polymerizable compound) and a binder is carried on a support. Is.

The above-mentioned image forming method is a method of polymerizing the polymerizable compound in the portion where the latent image of silver halide is formed. The present inventors have further invented a method capable of polymerizing a polymerizable compound in a portion where a latent image of silver halide is not formed, and this invention has already been applied for a patent (Japanese Patent Application No. 60-
210657). This method, by heating,
The reducing agent acts on the portion where the latent image of silver halide is formed to suppress the polymerization of the polymerizable compound and at the same time promotes the polymerization of other portions.

One of light-sensitive materials that can be used in these image forming methods is one having a constitution in which silver halide is present in oil droplets (or microcapsules) of a polymerizable compound (Japanese Patent Application No. 60-261888). Specification). The light-sensitive material having the above-mentioned structure has an advantage that the polymerization accelerating reaction (or polymerization suppressing reaction) of the polymerizable compound in the portion where the latent image of silver halide is formed smoothly proceeds.

[Summary of the Invention] The present inventor has conducted extensive research for the purpose of providing excellent photosensitive microcapsules that can be used in the production of photosensitive materials.

That is, it is an object of the present invention to provide a method for producing photosensitive microcapsules that is easy to produce, has good storage stability, and has extremely high sensitivity.

In the present invention, a silver halide emulsion and a reducing agent are dispersed in a polymerizable compound and an acid chloride is dissolved to prepare a hydrophobic photosensitive composition, and the photosensitive composition is prepared by using a polyamine and / or a polyol. An emulsion containing a photosensitive composition in the form of oil droplets is prepared by emulsifying and dispersing it in an aqueous medium containing, and an acid chloride, a polyamine and / or a polyol are formed at the interface between the oil droplets of the photosensitive composition and the aqueous medium. A shell of a polyamide resin and / or a polyester resin is formed around a core material containing a silver halide, a reducing agent and a polymerizable compound, the shell of which is polymerized to form a shell of a microcapsule. A method for producing a photosensitive microcapsule is provided.

The above-mentioned photosensitive microcapsules can be advantageously used as a photosensitive material, which is usually composed of a photosensitive layer formed by layering on a support in combination with a reducing agent. Therefore, the above reducing agent is preferably contained in the photosensitive microcapsules.

[Effects of the Invention] The photosensitive microcapsules of the present invention can be manufactured by using a method based on an interfacial polymerization method, which is one of the typical technologies for manufacturing microcapsules, and are therefore easy to manufacture. The outer shell is made of polyamide resin and /
Alternatively, since it is made of a material having high stability and elasticity such as polyester resin, it has an advantage that it is easy to handle and has good storage stability. Furthermore, since the outer shell made of the polyamide resin and / or the polyester resin can be formed at room temperature, the silver halide or the polymerizable compound as the core substance is not subject to heat history during the microencapsulation step. There are also advantages.

Therefore, by combining the photosensitive microcapsules of the present invention with a reducing agent to prepare a photosensitive material, a photosensitive material having good storage stability and high sensitivity can be obtained.

DETAILED DESCRIPTION OF THE INVENTION The photosensitive microcapsule of the present invention comprises an outer shell made of a polyamide resin and / or a polyester resin formed around a core material containing silver halide and a polymerizable compound. . The silver halide may be present inside the core material, or near the interface between the core material and the outer shell,
It may be partly embedded in the outer shell.

As the silver halide in the present invention, a silver halide known in the photographic art can be used. Any of silver chloride, silver bromide, silver iodide or silver chlorobromide, silver chloroiodide, silver iodobromide and silver chloroiodobromide can be used in the photosensitive microcapsules of the present invention. The halogen composition of the silver halide grains may be uniform or non-uniform on the surface and inside. In the present invention, the average grain size of the silver halide grains is preferably 0.001 μm to 10 μm, and particularly preferably 0.001 μm to 5 μm. Two or more kinds of silver halides having different crystal habits, halogen compositions, grain sizes and the like can be used in combination.

The wall material (outer shell material) forming the outer shell of the photosensitive microcapsule of the present invention is a polyamide resin and / or a polyester resin.

As an example of the method for producing the photosensitive microcapsules of the present invention, the following interfacial polymerization method can be mentioned.

An acid chloride is dissolved in a hydrophobic liquid composed of a photosensitive silver halide and a polymerizable compound, or a core material such as a reducing agent and a dye, if necessary, and a polyamine and / or polyol and a dispersant are contained in the acid chloride. A dispersion is prepared by dispersing the microdroplets in an aqueous medium. In addition, this dispersion contains
It is desirable to have a catalyst present which promotes the polycondensation reaction between the acid chloride and the polyamine and / or polyol.

When an alkaline substance is added so that the pH of the dispersion becomes neutral or weakly alkaline, a polyamide resin and / or a reaction product of an acid chloride and a polyamine and / or a polyol is added to the interface between the hydrophobic liquid and the aqueous medium. A wall (outer shell) made of a polyester resin is formed to obtain the desired photosensitive microcapsules.

The expressions polyamide resin and polyester resin in the present invention do not necessarily mean resins having only amide bond and ester bond bonding groups. For example, a resin in which a part of the bonding group of the polyamide resin is replaced with an ester bond is also included in the polyamide resin, and the same applies to the polyester resin.

Next, examples of acid chlorides, polyamines, and polyols used for forming the outer shell of the photosensitive microcapsules of the present invention will be described.

Examples of acid chlorides include adipoyl chloride, sebacoyl chloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, fumaroyl chloride, 1,4-cyclohexanedicarbonyl chloride, 4,4′-biphenyl. Examples thereof include dicarbonyl chloride, phosgene, 4,4′-sulfonyldibenzoyl chloride, polyester having an acid chloride functional group, and polyamide having an acid chloride functional group.

Examples of polyamines include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, p-phenylenediamine, m-phenylenediamine, piperazine, 2-
Methylpiperazine, 2,5-dimethylpiperazine, 2-
Examples thereof include hydroxytrimethylenediamine, diethylenetriamine, triethylenetetraamine, diethylaminopropylamine, tetraethylenepentamine, and amine adducts of epoxy compounds.

Examples of polyols are ethylene glycol, 1,4
-Butanediol, hexamethylene glycol, hydroquinone, resorcin, glycerin, pentaerythritol, bisphenol A, an alkali salt of 4-chlororesorcin, an alkali salt of 2,2'-bis (4-hydroxyphenyl) propane, 1,5- Alkali salt of dihydroxynaphthalene, alkali salt of phenolphthalene, alkali salt of phenol formaldehyde initial condensate, 4,
An alkali salt of 4'-dihydroxydiphenyl sulfone,
An alkaline salt of 2,4-dihydroxybenzophenone,
An alkaline salt of 4,4'-dihydroxybenzophenone,
An alkaline salt of 2,4-dihydroxybenzaldehyde,
Examples include melamine / formaldehyde precondensate and urea / formaldehyde precondensate. Also,
Polymers having a hydroxyl group such as polyvinyl alcohol, cellulose and starch can also be used.

When the silver halide and the polymerizable compound are introduced into the hydrophobic liquid of the core substance, the silver halide is usually produced as an emulsion (silver halide emulsion) using water as a dispersion medium, and then this is treated with a hydrophobic solvent. The method of mixing is generally used. Since the aqueous medium of the silver halide emulsion moves to the aqueous phase of the dispersion medium during the preparation of the emulsion dispersion for producing microcapsules, there is almost no water inside the core of the resulting photosensitive microcapsules. When the silver halide emulsion moves to the aqueous phase of the aqueous medium, the silver halide grains tend to move from the core substance phase (oil phase) to the dispersion medium phase (aqueous phase) along with water. , Silver halide tends to collect near the interface between the core material phase and the dispersion medium phase. Therefore, when the silver halide is introduced into the core substance by utilizing the silver halide emulsion, the silver halide grains are often present in the vicinity of the outer shell or inside the outer shell at a high concentration. Of course, even if the silver halide grains are located in such a position, there is no particular problem as a photosensitive capsule, and since exposure is facilitated, it can be said that this is preferable for improving sensitivity.

The introduction of silver halide grains into the core substance may be carried out not as a silver halide emulsion as described above but as a dispersion liquid in which silver halide grains are dispersed in an organic solvent.
Alternatively, a method of simply mixing the silver halide grains obtained as a powder with a polymerizable compound can be used.

From the aqueous liquid containing the photosensitive microcapsules obtained by the method as described above, the photosensitive microcapsules can be separated by using a known separation method such as evaporation of the aqueous solvent, filtration, or centrifugation. it can.

The polymerizable compound contained in the core material of the photosensitive microcapsule of the present invention is not particularly limited, and a known polymerizable compound can be used. As a method of using the photosensitive microcapsules or a photosensitive material using the same, when a polymerization treatment by heating is planned, a compound having a high boiling point (for example, a boiling point of 80 ° C. or higher) that is hard to volatilize during heating is used. Preferably. Further, the embodiment containing a color image-forming substance as an optional component described below is intended to immobilize the color image-forming substance by polymerization of the polymerizable compound. Therefore, the polymerizable compound has a plurality of polymerizable functional groups in the molecule. It is preferably a crosslinkable compound having a group.

The polymerizable compound used for the photosensitive microcapsules is
Generally, it is a compound having addition-polymerizability or ring-opening polymerizability. The compound having an addition-polymerizable group includes a compound having an ethylenically unsaturated group, and the compound having a ring-opening polymerizable group includes a compound having an epoxy group. A compound having an ethylenically unsaturated group is particularly preferable.

Examples of the compound having an ethylenically unsaturated group that can be used in the photosensitive microcapsules of the present invention include acrylic acid and salts thereof, acrylic acid esters, acrylamides, methacrylic acid and salts thereof, methacrylic acid esters and methacrylic acid. Examples thereof include amides, maleic anhydride, maleic acid esters, itaconic acid esters, styrenes, vinyl ethers, vinyl esters, N-vinyl heterocycles, allyl ethers, allyl esters and their derivatives.

Specific examples of the polymerizable compound that can be used in the present invention include acrylic acid esters such as n-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, furfuryl acrylate, ethoxyethoxyethyl acrylate, dicyclohexyloxy. Ethyl acrylate, nonylphenyloxyethyl acrylate, hexanediol diacrylate, butanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
Examples thereof include polyoxyethylenated bispheninol A diacrylate, hydroxypolyether polyacrylate, polyester acrylate and polyurethane acrylate.

Other specific examples of methacrylic acid esters include methyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, butanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, and pentaerythritol tetramethacrylate. Methacrylate and dimethacrylate of polyoxyalkylenated bisphenol A and the like can be mentioned.

The polymerizable compounds may be used alone or in combination of two or more. A substance obtained by introducing a polymerizable functional group such as a vinyl group or a vinylidene group into the chemical structure of a reducing agent or a color image forming substance which is an optional component described later can also be used as the polymerizable compound of the present invention.

In the photosensitive microcapsules of the present invention, the polymerizable compound is preferably used in the range of 0.05 to 1200% by weight based on silver halide. A more preferable range of use is 5 to 950% by weight.

The polymerizable compounds that can be used in the photosensitive microcapsules of the present invention are described in the application specifications for a series of photosensitive materials described above and below.

The photosensitive microcapsule of the present invention can be used in various applications including the production of various photosensitive materials with the above-mentioned constitution, but as an optional component, a reducing agent, a color image-forming substance, a sensitizing dye, an organic compound. Silver salts, various image formation accelerators (eg, bases or base precursors, oils, surfactants, thermal solvents, etc.), thermal polymerization inhibitors, thermal polymerization initiators, development terminators, fluorescent whitening agents, anti-fading agents , An antihalation or irradiation dye, a matting agent, an anti-smudge agent, a plasticizer, a water-releasing agent, a binder and the like can be contained.

When the photosensitive microcapsules of the present invention are used in the production of a photosensitive material, each of the above components (excluding a part of the sensitizing dye etc.) is used as an optional component in the photosensitive layer constituting the photosensitive material. It may be present in the capsule or outside the microcapsule. Details of each of the above components will be described in the description of the photosensitive material using the photosensitive microcapsules of the present invention described later.

The photosensitive microcapsules of the present invention have an average particle size of 0.
5 to 50 μm is preferable and 1 to 25 μm
Is more preferable.

The compound contained in the photosensitive microcapsule of the present invention and the compound optionally contained therein will be described in more detail below.

Of the components constituting the photosensitive microcapsules, silver halide is preferably prepared as a silver halide emulsion. Various types of silver halide emulsions known in the photographic art are used, but there is no particular limitation on the production of the photosensitive microcapsules of the present invention. For example, the silver halide emulsion may be a surface latent image type in which a latent image is mainly formed on the surface of a grain, or an internal latent image type in which a latent image is formed inside the grain. A direct reversal emulsion in which an internal latent image type emulsion and a nucleating agent are combined can also be used. Internal latent image type emulsions suitable for this purpose are described in US Pat. No. 2,592.
No. 250, No. 3761276, Japanese Patent Publication No. 58-3534, and Japanese Patent Application Laid-Open No. 58-136641. Preferred nucleating agents for combination with the above emulsions are U.S. Pat. Nos. 3,227,552 and 4,245.
No. 037, No. 4255511, No. 4266013
No. 4,276,364 and West German Published Patent (OL
S) No. 2635316.

There are various methods known in the photographic art for the preparation of silver halide emulsions, but there is no particular limitation regarding the production of the photosensitive microcapsules of the present invention. Silver halide emulsion,
It can be prepared by any known method such as acidic method, neutral method or ammonia method such as acidic method, neutral method or ammonia method. The reaction mode of the soluble silver salt and the soluble halogen salt may be a one-sided mixing method, a simultaneous mixing method, or a combination thereof. A back-mixing method in which grains are formed under conditions of excess silver ions and a controlled double-jet method in which pAg is kept constant can also be adopted. Further, in order to accelerate the grain growth, the addition concentration, the addition amount or the addition rate of the silver salt and the halogen salt to be added may be increased (JP-A-55-158124 and JP-A-55-1).
58124 and U.S. Pat. No. 3,650,757).

In the preparation of the above silver halide emulsion, it is preferable to use a hydrophilic colloid as the protective colloid. Examples of hydrophilic colloids are gelatin, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, cellulose sulfates, sodium alginate. , Sugar derivatives such as starch derivatives, and polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N
-A variety of synthetic hydrophilic polymeric substances such as single or copolymers such as vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole and polyvinylpyrazole can be mentioned. Of these, gelatin is preferred. As the gelatin, lime-processed gelatin, acid-processed gelatin or enzyme-processed gelatin may be used, and a hydrolyzed product or an enzymatically-decomposed product of gelatin may also be used.

The silver halide emulsion contains ammonia, an organic thioether derivative (see JP-B-47-386) and a sulfur-containing compound (see JP-A-53-144319) as a silver halide solvent in the step of forming silver halide grains.
Etc. can be used. Further, in the process of grain formation or physical ripening, a cadmium salt, a zinc salt, a lead salt, a thallium salt or the like may be allowed to coexist. Further, iridium chloride (III value or IV value) is used for the purpose of improving high illumination failure and low illumination failure.
Value), a water-soluble iridium salt such as ammonium hexachloroiridium salt, or a water-soluble rhodium salt such as rhodium chloride can be used.

Soluble salts may be removed from the silver halide emulsion after formation of a precipitate or after physical ripening. In this case, it can be carried out according to the Nudel washing method or the sedimentation method. The silver halide emulsion may be used without ripening, but it is usually chemically sensitized before use. In the emulsion for conventional type light-sensitive material, known sulfur sensitizing method, reduction sensitizing method, noble metal sensitizing method, or a sensitizing method using a sensitizing dye described in Japanese Patent Application No. 60-139746 is used alone or in combination. Can be used. These chemical sensitizations can also be carried out in the presence of a nitrogen-containing heterocyclic compound (JP-A-58-126526 and 58-2).
(See each publication of 15644).

A photosensitive composition in which a silver halide is contained in a polymerizable compound (or an oily solvent containing the polymerizable compound; hereinafter sometimes simply referred to as a polymerizable compound) using the silver halide emulsion as described above. Can be prepared. Further, in the preparation of the photosensitive composition, in addition to the silver halide emulsion,
It is also possible to use a dry silver halide powder produced by freeze-drying or the like. The photosensitive composition containing these silver halides can be obtained by stirring with a homogenizer, blender, mixer, or other commonly used stirrer.

In the preparation of the photosensitive composition containing the above silver halide,
It is preferable to dissolve the copolymer represented by the following formula in the polymerizable compound.

[In the above formula, A is a repeating unit derived from a hydrophilic monomer, B is a repeating unit derived from a hydrophobic monomer, and x and y are respectively repeating units constituting the polymer. Means a numerical value indicating the mol% of A and B occupied, and 5 ≦ x ≦ 95, 5 ≦ y ≦ 95, and x + y = 100].

The copolymer represented by the above formula has the function of easily and uniformly dispersing the above silver halide (including silver halide emulsion) or other various components in the polymerizable compound. Further, the above-mentioned copolymer also has a function of precipitating silver halide at the interface between the polymerizable compound (photosensitive composition) and the aqueous solvent in the microencapsulation treatment described later. Therefore, by using the above copolymer, the silver halide can be easily included in the wall material that constitutes the outer shell of the microcapsule.

The copolymer is preferably used in an amount of 0.01 to 5% by weight based on silver halide. More preferably, it is in the range of 0.05% by weight to 2% by weight.

Any component such as a reducing agent or a color image forming substance may be dissolved, emulsified or dispersed in the photosensitive composition. In addition, a substance necessary for the microencapsulation treatment (including a wall material) may be included in the photosensitive composition.

The photosensitive microcapsules of the present invention can be used as a photosensitive adhesive or the like, and can be particularly advantageously used for image formation in the state of a photosensitive material arranged in a layer on a support.

When a photosensitive material is produced using the photosensitive microcapsules of the present invention, the microcapsules are dispersed in a suitable solvent to prepare a coating solution. The aqueous liquid containing the photosensitive microcapsules obtained in the final stage of the production of the microcapsules described above can be used as it is for the preparation of the coating liquid. Other components added to the light-sensitive material such as a reducing agent may be added to this coating liquid. When the aqueous liquid containing the microcapsules is used as it is for the preparation of the coating liquid, each component of the light-sensitive material may be added before and after the microcapsulation process described above.

A photosensitive material can be easily produced by applying the coating solution prepared as described above onto various supports described below and drying. The application of the coating solution onto the support can be easily carried out according to known techniques.

The photosensitive material using the photosensitive microcapsules of the present invention will be described below.

The above-mentioned light-sensitive material comprises a support and a light-sensitive layer containing the light-sensitive microcapsules of the present invention and a reducing agent.

The reducing agent that can be used in the photosensitive microcapsules and the photosensitive material has a function of reducing silver halide and / or a function of accelerating (or suppressing) the polymerization of the polymerizable compound. There are various kinds of substances as the reducing agent having the above function. Examples of the reducing agent include hydroquinones, catechols, p-aminophenols, p-phenylenediamines, 3-pyrazolidones, 3-aminopyrazoles, 4-amino-5-pyrazolones, 5-aminouracils, 4,5-Dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- or p-sulfonamidophenols, o- or p-
Sulfonamide naphthols, 2-sulfonamidoindanones, 4-sulfonamido-5-pyrazolones, 3
-Sulfonamide indoles, sulfonamide pyrazolobenzimidazoles, sulfonamide pyrazolotriazoles, α-sulfonamide ketones, hydrazines and the like. By adjusting the type and amount of the reducing agent, it is possible to polymerize the polymerizable compound in the portion where the latent image of silver halide is formed or the portion where the latent image is not formed. In addition, in a system in which a polymerizable compound in a portion where a latent image of silver halide is not formed is polymerized, it is particularly preferable to use a 1-phenyl-3-pyrazolidone derivative as a reducing agent.

Regarding various reducing agents having the above functions, Japanese Patent Application Nos. 60-22980, 60-29894 and 60-
68874, 60-226084, 60-22
No. 7527 and No. 60-227528. Further, regarding the above-mentioned regenerating agent, T.K. James
Author “The Theory of the Photographic Process”
Fourth Edition, pp. 291-334 (1977), Research
Disclosure Magazine Vol.170, 17th June, 1978
029 (pages 9 to 15), and Vol. 176, 19 of the same magazine.
It is also described in December 1978, No. 17643 (pages 22 to 31). Also in the photosensitive microcapsule of the present invention and the photosensitive material using the same, the reducing agents (including those described as a developing agent or a hydrazine derivative) described in the above specifications and references can be effectively used. Therefore, the “reducing agent” in the present specification includes the reducing agents described in the above respective specifications and documents.

These reducing agents may be used alone or as a mixture of two or more reducing agents as described in the above specification. When two or more reducing agents are used in combination, the reducing agents may interact with each other by first promoting the reduction of silver halide (and / or organic silver salt) by so-called superadditivity. To cause polymerization of the polymerizable compound via an oxidation-reduction reaction with another reducing agent in which the oxidant of the first reducing agent generated by reduction of silver halide (and / or organic silver salt) coexists Etc. are possible. However, in actual use, it is difficult to specify which of the above actions because the above reactions can occur simultaneously.

In addition, as described above, the reducing agent may be contained in the microcapsules or may be present outside the microcapsules in the photosensitive material using the photosensitive microcapsules of the present invention. When the reducing agent is contained in the microcapsules, it is generally dissolved or dispersed in the core substance before use. Generally, it is preferable that the reducing agent be contained in the microcapsules from the viewpoint of smooth progress of the reaction, but when the heat development treatment is planned as a method of using the light-sensitive material, the reducing agent permeates the microcapsules during heating. Therefore, there is no particular problem even if the reducing agent is present outside the microcapsules.

Specific examples of the reducing agent include pentadecylhydroquinone, 5-t-butylcatechol, p- (N, N-diethylamino) phenol, 1-phenyl-4-methyl-
4-hydroxymethyl-3-pyrazolidone, 1-phenyl-4-methyl-4-heptadecylcarbonyloxymethyl-3-pyrazolidone, 2-phenylsulfonylamino-4-hexadecyloxy-5-t-octylphenol, 2-phenyl Sulfonylamino-4-t-butyl-5-hexadecyloxyphenol, 2- (N-butylcarbamoyl) -4-phenylsulfonylaminonaphthol, 2- (N-methyl-N-octadecylcarbamoyl) -4-sulfonylamino Naphthol, 1-acetyl-2-phenylhydrazine, 1-acetyl-2-
{(P or o) -aminophenyl} hydrazine, 1-
Formyl-2-{(p or o) -aminophenyl} hydrazine, 1-acetyl-2-{(p or o) -methoxyphenyl} hydrazine, 1-lauroyl-2-
{(P or o) -aminophenyl} hydrazine, 1-
Trityl-2- (2,6-dichloro-4-cyanophenyl) hydrazine, 1-trityl-2-phenylhydrazine, 1-phenyl-2- (2,4,6-trichlorophenyl) hydrazine, 1- {2- (2,5-di-t-pentylphenoxy) butyroyl} -2-{(p- or o) -aminophenyl} hydrazine, 1- {2- (2,
5-di-t-pentylphenoxy) butyroyl} -2-
{(P or o) -aminophenyl} hydrazine pentadecyl fluorocaprylate, 3-indazolinone,
1- (3,5-dichlorobenzoyl) -2-phenylhydrazine, 1-trityl-2-[{2-N-butyl-N
-Octylsulfamoyl) -4-methanesulfonyl}
Phenyl] hydrazine, 1- {4- (2,5-di-t-
Pentylphenoxy) butyroyl} -2-{{(p or o) -methoxyphenyl} hydrazine, 1- (methoxycarbonylbenzohydryl) -2-phenylhydrazine, 1-formyl-2- [4- (2, 4-di-t-pentylphenoxy) butylamido} phenyl] hydrazine, 1-acetyl-2- [4- {2- (2,4-di-t).
-Pentylphenoxy) butylamido} phenyl] hydrazine, 1-trityl-2-[{2,6-dichloro-4]
-(N, N-di-2-ethylhexyl) carbamoyl}
Phenyl] hydrazine, 1- (methoxycarbonylbenzohydryl) -2- (2,4-dichlorophenyl) hydrazine, and 1-trityl-2-[{2- (N-ethyl-N-octylsulfamoyl) -4. -Methanesulfonyl {phenyl] hydrazine and the like can be mentioned.

In the photosensitive microcapsules and the light-sensitive material of the present invention, the reducing agent is in the range of 0.1 to 1500 mol% with respect to 1 mol of silver (including silver halide described below and an organic silver salt which is an optional component). Preference is given to using.

There is no particular limitation on the support of the light-sensitive material using the light-sensitive microcapsules of the present invention, but when heat development processing is planned as a method of using the light-sensitive material, use a material that can withstand this processing temperature. Is preferred. Examples of the material that can be used for the support include glass, paper, high-quality paper, coated paper, cast coated paper, synthetic paper, metal and analogs thereof, polyester, acetyl cellulose,
Examples thereof include films such as cellulose ester, polyvinyl acetal, polystyrene, polycarbonate, polyethylene terephthalate, and paper laminated with a resin material or a polymer such as polyethylene.

The photosensitive material using the photosensitive microcapsules of the present invention,
Although a polymer image can be obtained by polymerizing the polymerizable compound with the above-described structure, a color image can be formed by including a color image forming substance as an optional component in the photosensitive layer. As described above, the color image forming substance may be contained in the microcapsule or may be present outside the microcapsule in the light-sensitive material using the photosensitive microcapsule of the present invention. It is preferable to use it after dissolving it therein.

The color image-forming substance that can be used in the light-sensitive material is not particularly limited, and various types can be used. That is, a substance that is itself colored (dye or pigment), or energy that is colorless or pale but is external (heat, pressure, light irradiation, etc.) or another component (developing agent) A substance (color former) that develops a color upon contact is also included in the color image forming substance. When a plurality of the color image-forming substances are used, they are used in combination with at least three kinds of silver halide emulsions sensitive to mutually different spectral regions (the silver halide emulsion will be described later) to correspond to the respective emulsions. Thus, a color image can be easily formed. An example of color image formation which can be used for a light-sensitive material is described in Japanese Patent Application No. 59-195407.

Dyes and pigments, which are themselves colored substances, are commercially available as well as various documents (for example, "Dye Handbook" edited by the Society of Synthetic Organic Chemistry, published in 1970, "Latest Pigment Handbook" edited by the Japan Pigment Technology Association, Showa). The publicly known ones described in 1992) can be used. These dyes or pigments are used after being dissolved or dispersed.

On the other hand, examples of the substance that develops color by some energy such as heating, pressurization, and light irradiation are thermochromic compounds,
Known are piezochromic compounds, photochromic compounds, and leuco bodies such as triarylmethane dyes, quinone dyes, indigoid dyes, and azine dyes. All of them develop color by heating, pressurizing, light irradiation or air oxidation.

Examples of the substance that develops a color upon contact with another component include various systems that develop a color by an acid-base reaction between two or more components, a redox reaction, a coupling reaction, a chelate formation reaction and the like. For example, pressure-sensitive copying paper (pages 29 to 58) and azography (87 to 87) described in "Introduction to Special Paper Chemistry" by Hiroyuki Moriga (published in 1975).
95), thermosensitive coloring due to chemical changes (118-120)
Page) etc., or the proceedings of the seminar “Latest dye chemistry-Attractive utilization and new development as functional dyes” hosted by Kinki Chemical Industry Association, pages 26-32, (19
The coloring system described in June 19, 80) can be used. Specifically, a color-developing system composed of a colorant having a partial structure such as lactone, lactam, and spiropyran used for pressure-sensitive paper and an acidic substance (developing agent) such as acid clay or phenol; an aromatic diazonium salt or Diazotate, diazosulfonates and naphthols,
Systems utilizing azo coupling reactions of anilines and active methylenes; reactions of hexamethylenetetramine with ferric ions and gallic acid, reactions of phenolphthalein-complexones with alkaline earth metal ions, etc. Chelate forming reaction; a redox reaction such as a reaction between ferric stearate and pyrogallol or a reaction between silver behenate and 4-methoxy-1-naphthol can be used.

Other optional components that can be contained in the photosensitive layer of the photosensitive material using the photosensitive microcapsules of the present invention,
As described above, sensitizing dyes, organic silver salts, various image formation accelerators, thermal polymerization inhibitors, thermal polymerization initiators, development terminators, fluorescent whitening agents, anti-fading agents, halation or anti-irradiation dyes, mats. Agent, anti-smadge agent, plasticizer,
Water release agent, binder, etc.

Examples of sensitizing dyes that can be used in the photosensitive microcapsules and photosensitive materials of the present invention are described in Japanese Patent Application No. 60-139746, and examples of organic silver salts are Japanese Patent Application No. 60-141799. Each is described in the specification. Further, a light-sensitive material using a base or a low-base precursor is described in Japanese Patent Application No. 60-227528, and a light-sensitive material using a thermal polymerization initiator is described in Japanese Patent Application No. 60-223347. There is a description. Further, regarding a light-sensitive material using an antifoggant, Japanese Patent Application Nos. 60-294337 and 60-2943.
38, 60-294339 and 60-294.
No. 341, and a light-sensitive material using a polyethylene glycol derivative as a heat solvent is described in Japanese Patent Application No. 60-294340. Examples of other components and their use modes are also described in the specification of the application relating to the series of light-sensitive materials described above, and research.
Disclosure Magazine Vol.170, 1st June 1978
7029 (pages 9 to 15).

The sensitizing dye that can be used in the photosensitive microcapsules and the light-sensitive material of the present invention is not particularly limited, and a silver halide sensitizing dye known in the photographic art can be used. The sensitizing dyes include methine dyes, cyanine dyes, merocyanine dyes, complex cyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. These sensitizing dyes may be used alone or in combination. In particular, for the purpose of supersensitization, it is common to use a combination of sensitizing dyes. Further, together with the sensitizing dye, a dye which does not have a spectral sensitizing effect itself, or a substance which does not substantially absorb visible light but exhibits supersensitization may be used together. The addition amount of the sensitizing dye is generally about 10 ^{-8 to} 10 ^-2 mol per mol of silver halide milk.

In the light-sensitive material using the light-sensitive microcapsules of the present invention, the addition of the organic silver salt is particularly effective when heat development processing is planned as a method of using the light-sensitive material. That is, when heated to a temperature of 80 ° C. or higher, the organic silver salt is considered to participate in the redox reaction using the latent image of silver halide as a catalyst. In this case, it is preferable that the silver halide and the organic silver salt are in contact with or in close proximity to each other. Examples of the organic compound that constitutes the organic silver salt include an aliphatic or aromatic carboxylic acid, a thiocarbonyl group-containing compound having a mercapto group or α-hydrogen, and an imino group-containing compound. Of these, benzotriazole is particularly preferable. The above organic silver salt is generally used in an amount of 0.01 to 10 mol, preferably 0.01 to 1 mol, per mol of silver halide. The same effect can be obtained by adding an organic compound (for example, benzotriazole) constituting the organic silver salt to the photosensitive layer instead of the organic silver salt.

Various image forming accelerators can be used in the photosensitive material using the photosensitive microcapsules of the present invention. As the image formation accelerator, promotion of redox reaction between a silver halide (and / or organic silver salt) and a redox agent,
It has a function of promoting the movement of the image-forming substance from the light-sensitive material to the image-receiving material or the image-receiving layer (which will be described later). The image formation accelerator is classified into a base or a base precursor, an oil, a surfactant, an anti-caprying agent, a thermal solvent, etc., from the viewpoint of physicochemical function. However, these substance groups generally have a composite function, and usually have some of the above-mentioned accelerating effects together. Therefore, the above classification is convenient, and in fact, one compound often has a plurality of functions.

Examples of image forming accelerators include bases, base precursors, oils, surfactants, antifoggants, and hot solvents.

Examples of preferred bases include alkali metal or alkaline earth metal hydroxides as inorganic bases, zinc hydroxide or a combination of zinc oxide and a chelating agent such as sodium picolinate, a secondary or tertiary phosphate, Examples thereof include borates, carbonates, quinolinates, metaborates; ammonium hydroxides, quaternary alkylammonium hydroxides, hydroxides of other metals, etc., and aliphatic amines as organic bases. (Trialkylamines, hydroxylamines, aliphatic polyamines); aromatic amines (N-alkyl-substituted aromatic amines, N-hydroxylalkyl-substituted aromatic amines and bis [p- (dialkylamino) phenyl] Examples include methanes, heterocyclic amines, amidines, cyclic amidines, guanidines, and cyclic guanidines, and particularly p a 7 or more is preferable.

As the base precursor, a salt of an organic salt and a base that is decarboxylated by heating, a compound that releases an amine by a reaction such as intramolecular nucleophilic substitution reaction, Rossen rearrangement, Beckmann rearrangement, etc., causes a reaction to cause the reaction of some base by heating. Compounds that release and generate a base by electrolysis are preferably used. Specific examples of the base precursor include guanidine trichloroacetic acid, piperidine trichloroacetic acid, morpholine trichloroacetic acid, p-toluidine trichloroacetic acid, 2-picoline trichloroacetic acid, phenylsulfonylacetic acid guanidine, 4-chlorophenylsulfonylacetic acid guanidine, and 4-methyl-sulfonyl. Examples thereof include guanidine phenylsulfonylacetate and guanidine 4-acetylaminomethylpropiolate.

In the photosensitive material using the photosensitive microcapsules of the present invention,
The base or base precursor can be used in a wide range of amounts. The base or base precursor is suitably used in an amount of 50% by weight or less in terms of weight of the coating film of the photosensitive layer, more preferably 0.01% by weight to 40% by weight. In the present invention, the base and / or the base precursor may be used alone or as a mixture of two or more kinds. The base or base precursor is generally preferably present in the photosensitive layer outside the microcapsules.

As the oil, a high boiling point organic solvent used as a solvent for emulsifying and dispersing a hydrophobic compound can be used.

Examples of the surfactant include pyridinium salts, ammonium salts, phosphonium salts described in JP-A-59-74547 and polyalkylene oxides described in JP-A-59-57231.

Examples of the antifoggant include compounds having a 5- or 6-membered nitrogen-containing heterocyclic structure (including compounds having a cyclic amide structure), thiourea derivatives, thioether compounds, thiol derivatives, etc., which are known in the conventional photographic art. Can be mentioned.

As the hot solvent, a compound which can be a solvent for the reducing agent, a compound which is a substance having a high dielectric constant and is known to accelerate the physical development of the silver salt, and the like are useful. As a useful thermal solvent,
Polyethylene glycols described in U.S. Pat. No. 3,347,675, derivatives of polyethylene oxide such as oleic acid ester, beeswax, monostearin and -SO.
High dielectric constant compounds having _2- and / or -CO- groups, polar substances described in U.S. Pat. No. 3,667,959, 1,10-decane described in Research Disclosure, December 1976, pages 26-28. Diol, methyl anisate, biphenyl suberate and the like are preferably used.

The thermal polymerization initiator that can be used for the photosensitive microcapsules and the photosensitive material of the present invention is a compound that generally undergoes thermal decomposition under heating to generate a polymerization initiation species (particularly a radical), and is usually used as an initiator for radical polymerization. It is what has been. Regarding the thermal polymerization initiator, "Addition Polymerization / Ring-Opening Polymerization" 1983, edited by Editorial Committee of Polymer Experiments, Polymer Society of Japan, 1983.
, Kyoritsu Shuppan), pp. 6-18. Specific examples of the thermal polymerization initiator include azobisisobutyronitrile, 1,1′-azobis (1-cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate, 2,2-azobis ( 2-Methylbutyronitrile), azo compounds such as azobisdimethylvaleronitrile, benzoyl peroxide, di-t-oxide, dicumyl peroxide, t-butylhydroperoxide, cumene hydroperoxide and other organic peroxides , Hydrogen peroxide, inorganic peroxides such as potassium persulfate and ammonium persulfate, and sodium p-toluenesulfinate. The amount of the thermal polymerization initiator used is preferably 0.1 to 120% by weight, more preferably 1 to 10% by weight, based on the polymerizable compound.

The development terminator that can be used in the photosensitive microcapsules and the light-sensitive material of the present invention is a compound that, after proper development, rapidly neutralizes or reacts with a base to lower the concentration of the base in the film and stop development. It is a compound that interacts with silver and silver salts to suppress development. Specific examples thereof include an acid precursor that releases an acid when heated, an electrophilic compound that causes a placement reaction with a coexisting base when heated, a nitrogen-containing heterocyclic compound, and a mercapto compound. Examples of the acid precursor include oxime esters described in Japanese Patent Application Nos. 58-216928 and 59-48305, compounds releasing an acid by the Rossen rearrangement described in Japanese Patent Application No. 59-85834, and the like. Examples of electrophilic compounds that undergo a substitution reaction with a base upon heating include compounds described in Japanese Patent Application No. 59-85836.

As the anti-smudge agent that can be used in the light-sensitive material using the light-sensitive microcapsules of the present invention, solid particulate matter at room temperature is preferable. Specific examples thereof include starch particles described in British Patent No. 12322347, polymer fine powder described in U.S. Pat. No. 3,625,736, and microcapsule particles containing no color former described in British Patent No. 1235991. U.S. Pat. No. 2,711,375
Cellulose fine powder described in the specification, talc, kaolin,
Examples thereof include inorganic particles such as bentonite, pyrophyllite, zinc oxide, titanium oxide, and alumina. The average particle size of the particles is 3 to 50 μm in volume average diameter.
The range of m is preferable, and the range of 5 to 40 μm is more preferable. It is more effective that the particles are larger than microcapsules.

The binder that can be used in the light-sensitive material and the image-receiving material described later can be contained in the light-sensitive layer or the image-receiving layer (described later) alone or in combination. It is preferable to mainly use a hydrophilic binder. As the hydrophilic binder, a transparent or translucent hydrophilic binder is typical, and examples thereof include gelatin, gelatin derivatives,
It includes natural substances such as cellulose derivatives, starch, arabic gum and the like, and synthetic polymer substances such as water-soluble polyvinyl compounds such as polyvinyl alcohol, polyvinylpyrrolidone and acrylamide polymers. Other synthetic polymeric materials include dispersed vinyl compounds in the form of latices, which increase the dimensional stability of photographic materials in particular.

Examples of layers that can be optionally provided in the photosensitive material using the photosensitive microcapsules of the present invention include an image receiving layer, a heating element layer, a protective layer, an antistatic layer, an anti-curl layer, a peeling layer, and a matting agent layer. be able to.

The photosensitive material can form an image on the image receiving material by transferring an unpolymerized polymerizable compound to the image receiving material as described later. Further, in an embodiment in which the photosensitive layer contains a color image-forming substance, the color image-forming substance can be similarly transferred to the image receiving material to form an image. The image receiving material comprises an image receiving layer having a function of fixing a color image forming substance released from the light sensitive material, and a support. Instead of using an image-receiving material, the image-receiving layer can be coated on a support common to the photosensitive layer as described above for any of the photosensitive materials of the present invention.

The image-receiving layer can be configured in various forms using various compounds according to the color-forming system of the color image-forming substance described above. For example, when a color-developing system comprising a color-developing agent and a color-developing agent is used, the image-receiving layer may contain the color-developing agent. Further, the image receiving layer may be composed of at least one layer containing a mordant. The mordant can be selected from compounds known in the photographic art and the like in consideration of conditions such as the type of color image forming substance and used. If necessary, a plurality of mordants having different mordant strengths may be used to form the image receiving element with two or more image receiving layers. When the image receiving layer is located on the surface of the light-sensitive material or the image receiving material, it is preferable to further provide a protective layer.

An example of an image receiving material that can be used together with a light-sensitive material and an image-receiving layer that can be provided in the light-sensitive material are described in Japanese Patent Application No. 60-212284, and a light-sensitive material using a heating element layer is Japanese Patent Application No. -135568, respectively. In addition, examples of other auxiliary layers and usage modes thereof are also described in the specification of the above-mentioned series of photosensitive materials.

The method of using the photosensitive material using the photosensitive microcapsules of the present invention will be described below.

The light-sensitive material may be imagewise exposed at the same time or after imagewise exposure.
It is used after being developed.

Although various exposing means can be used as the exposing method, a latent image of silver halide is generally obtained by imagewise exposure of radiation including visible light. The type of light source and the amount of exposure are
Sensitive wavelength of silver halide (when dye sensitization is performed,
It can be selected according to the sensitized wavelength) and the sensitivity. The original image may be a monochrome image or a color image.

The photosensitive material using the photosensitive microcapsules of the present invention,
By carrying out a development treatment using a liquid described in JP-B-45-111149, etc., the polymerizable compound in the portion where the latent image exists can be polymerized. Further, the method described in Japanese Patent Application No. 59-191353, which carries out the heat development treatment as described above, has an advantage that the operation is simple and the treatment can be carried out in a short time since it is a dry treatment. Therefore, the latter is particularly preferable as the method of using the light-sensitive material.

As a heating method in the heat development treatment, various conventionally known methods can be used. Further, like the light-sensitive material described in Japanese Patent Application No. 60-135568, the light-sensitive material may be provided with a heating element layer and used as a heating means. The heating temperature is generally 80 ° C to 200 ° C, preferably 100 ° C to 160 ° C. The heating time is
Generally, it is 1 second to 5 minutes, preferably 5 seconds to 1 minute.

The photosensitive material using the photosensitive microcapsules of the present invention,
By carrying out the development processing as described above, the polymerizable compound contained in the microcapsules in the portion where the latent image of silver halide is formed or the portion where the latent image is not formed can be polymerized. Incidentally, in the above-mentioned development processing, the polymerizable compound in the portion where the latent image of silver halide is formed is generally polymerized.
It is also possible to polymerize the polymerizable compound in the portion where the latent image of silver halide is not formed by adjusting the kind and amount of the reducing agent as in the light-sensitive material described in 10657 specification.

The photosensitive material subjected to the development processing as described above bursts the microcapsules containing the unpolymerized polymerizable compound, transfers the unpolymerized polymerizable compound to the image receiving material, and forms a polymer image on the image receiving material. be able to. Further, a dye or a pigment may be fixed to the polymer image to obtain a dye image.

The photosensitive material using the photosensitive microcapsules of the present invention,
In the embodiment in which the photosensitive layer contains a color image-forming substance, the polymerizable compound is polymerized and cured as described above, thereby immobilizing the color image-forming substance in the portion where the latent image is formed (or the portion where the latent image is not formed). Next, the image receiving material is pressed onto the photosensitive material in which the color image forming substance in the cured portion is immobilized so that the microcapsules in the uncured portion are ruptured and the color image forming substance is transferred to the image receiving material. can do. Various conventionally known methods can be used for the pressing means. The image forming method using an image receiving element such as an image receiving material is described in Japanese Patent Application No.
It is described in the specification of 0-1212284.

The photosensitive material using the photosensitive microcapsules of the present invention,
Black and white or color photography and printing materials, printing materials, printing plates, X-ray materials, medical materials (for example, ultrasonic diagnostic machine CRT imaging materials), computer graphic hard copy materials, copier materials. There are many uses such as wood.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 Preparation of Silver Halide Emulsion 40 g of gelatin and 23.8 g of potassium bromide were dissolved in 3 l of water, heated to 50 ° C., and stirred for 3 g of silver nitrate.
What melt | dissolved 4 g in 200 ml of water was added in 10 minutes. Then, a solution prepared by dissolving 3.3 g of potassium iodide in 100 ml of water was added over 2 minutes. The pH of the silver iodobromide emulsion thus obtained was adjusted, precipitated to remove excess salts, and then adjusted to pH 6.0 to obtain a silver iodobromide emulsion with a yield of 400 g.

Preparation of benzotriazole silver emulsion 28 g of gelatin and 13.2 g of benzotriazole were added to 3 parts of water.
Dissolved in 000 ml. The solution was stirred while maintaining the temperature at 40 ° C., and a solution prepared by dissolving 17 g of silver nitrate in 100 ml of water was added over 2 minutes. Excess salt was precipitated and removed by adjusting the pH of the obtained emulsion. Then adjust the pH to 6.3
It was adjusted to 0 to obtain a benzotriazole silver emulsion. The yield of emulsion was 400 g.

Preparation of Photosensitive Composition 0.40 g of the following copolymer and 6.00 g of Vargasscript Red I-6-B (manufactured by Ciba Geigy) were dissolved in 100 g of trimethylolpropane triacrylate. A solution prepared by dissolving 0.22 g of Emamarex NP-8 (manufactured by Nippon Emulsion Co., Ltd.), 0.65 g of the following hydrazine derivative and 0.73 g of the following developing agent in 2.4 g of methylene chloride was added to 10.8 g of the above solution. It was 2.4 g of a silver halide emulsion prepared as above in the above solution,
A mixture of 2 g of benzotriazole silver emulsion and 0.066 g of benzotriazole was added, and the mixture was stirred with a homogenizer at 15,000 rpm for 5 minutes to obtain a photosensitive composition (average emulsion particle size: 0.8 μm).

(Copolymer) (Hydrazine derivative) (Developer) Preparation of microcapsule solution 30% of terephthaloyl chloride in the above photosensitive composition
An ethyl acetate solution (9 g) was dissolved in methyl cellulose (degree of substitution of methoxy group: 1.8, average molecular weight: 1500).
0) was added to 50 g of a 4% aqueous solution, and the mixture was emulsified by stirring at 5000 rpm for 1 minute using a homogenizer (average emulsified particle diameter: 8 μm).

Into this aqueous emulsion, 15 g of a 5% aqueous solution of diethylenetriamine was gradually added dropwise while stirring at 1000 rpm. After stirring for 60 minutes, the pH was adjusted to 8.0 or higher with a 10% sodium hydroxide aqueous solution to perform encapsulation, and a dispersion of photosensitive microcapsules having a polyamide resin shell was obtained (average of capsules). Particle size: 10μ
m).

[Example 2] 9 g of a 30% ethyl acetate solution of terephthaloyl chloride in the same photosensitive composition as that used in Example 1
Was dissolved in methylcellulose (degree of substitution of methoxy group: 1.8, average molecular weight: 1500
0) was added to 50 g of a 4% aqueous solution, and the mixture was emulsified by stirring at 5000 rpm for 1 minute using a homogenizer (average emulsified particle diameter: 7 μm).

To this aqueous emulsion, 30 g of a 5% solution of bisphenol A dissolved in an alkaline aqueous solution was gradually added dropwise while stirring at 1000 rpm. Thereafter, the pH was adjusted to 8.0 or higher and stirring was continued for about 1 hour to obtain a dispersion liquid of photosensitive microcapsules having a polyester resin outer shell (capsule average particle diameter: 10 μm).

[Evaluation as Photosensitive Material] Preparation of Photosensitive Material To 10.0 g of the microcapsule dispersion liquid, 3.6 g of a 5% by weight aqueous solution of guanidine trichloroacetate was added to obtain 100 μm.
It was coated on an m-thick polyethylene terephthalate sheet with a # 40 coating rod and dried at about 40 ° C. to prepare a light-sensitive material according to the present invention.

Preparation of image receiving material To 125 g of water, 11 g of 40% sodium hexametaphosphate aqueous solution was added, and further 34 g of zinc 3,5-di-α-methylbenzylsalicylate and 82 g of 55% calcium carbonate slurry were mixed and roughly dispersed by a mixer. The liquid was dispersed with a Dynamill disperser, and to 200 g of the obtained liquid, 6 g of 50% SBR latex and 55 g of 8% polyvinyl alcohol aqueous solution were added and uniformly mixed. An image receiving material was prepared by uniformly applying this mixed solution onto art paper having a weight of 43 g / m ² so as to have a wet film thickness of 30 μm, and then drying.

Evaluation of Photosensitive Material The photosensitive material was imagewise exposed at 2000 lux for 1 second using a tungsten bulb, and then heated on a hot plate heated to 125 ° C. for 40 seconds. Then, the light-sensitive material was overlaid on the image receiving material and passed through a 350 kg / cm ² pressure roller. As a result, a positive image with a reflection density of approximately 1.0 was obtained using the photosensitive materials of Examples 1 and 2.
However, the densities on the image receiving paper corresponding to the exposed portions were all 0.1 or less.

As is clear from the above results, the light-sensitive material using the capsule of the present invention has a low minimum density (exposed portion) and an S / N
It was found to give a good positive image with a high ratio.

Claims (3)

[Claims] 1. A hydrophobic photosensitive composition is prepared by dispersing a silver halide emulsion and a reducing agent in a polymerizable compound and dissolving an acid chloride. The photosensitive composition is prepared by adding a polyamine and / or An emulsion containing a photosensitive composition in the form of oil droplets is prepared by emulsifying and dispersing in an aqueous medium containing a polyol, and acid chloride and polyamine and / or at the interface between the oil droplets of the photosensitive composition and the aqueous medium. A shell of a polyamide resin and / or a polyester resin is formed around a core material containing a silver halide, a reducing agent and a polymerizable compound, which is characterized by polymerizing a polyol to form a shell of a microcapsule. To produce photosensitive microcapsules. 2. The method for producing photosensitive microcapsules according to claim 1, wherein a color image-forming substance is further dispersed in the polymerizable compound. 3. The average particle size of the microcapsules is 0.
The method for producing photosensitive microcapsules according to claim 1, which has a thickness of 5 to 50 μm.