JPH04333848A - Light image forming material - Google Patents

Abstract

PURPOSE:To provide the light image forming material having excellent water resistance and transparency. CONSTITUTION:This light image forming material consists of a base, a light image forming layer formed by applying a coating liquid contg. either of microcapsules enclosing both of oxidation color developable leuco dyes and a photooxidizing agent and microcapsules enclosing an emulsion formed by emulsion dispersion after dissolution of a reducing agent into an org. solvent insoluble or hardly soluble in water or reducing agent on the case and drying the coating, and >=1 layers of protective layers provided on the light image forming layer. At least one layer of the protective layers contain a silicone resin as an essential component.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoimage-forming material, and more particularly to a photoimage-forming material that has excellent water resistance and transparency and can be used for proof paper, printout paper, OHP films, and the like.

0002

2. Description of the Related Art Conventionally, so-called free radical photography has been known as one of the non-silver salt photosensitive materials, in which exposed areas become visible when imagewise exposed. In this case, it is particularly effective to use a photo-image-forming material that radically oxidizes various leuco dyes using a photo-oxidizing agent that becomes reactive upon light irradiation and forms the dye in an image-wise manner (for example, ,
Photo. Sci. Eng. , Volume 5, 98-103
Page (1961), Japanese Patent Publication No. 43-29,407, Japanese Patent Application Publication No. 55-55,335, Japanese Patent Application Publication No. 60,329, 1982,
JP-A-62-66,254).

However, in such photoimage-forming materials, when the photoimage-forming material is exposed to indoor light, sunlight, or white light after the dye is formed by exposure to form an image, residual dyes remain. Since the photo-oxidizing agent oxidizes the leuco dye to cause a dye-forming reaction, it has the disadvantage that it is difficult to handle it in a bright room.

[0004] In order to overcome such drawbacks, it is possible to preserve the original image by, for example, spraying or impregnating the photoimaging material after the image has been formed with a reducing agent solution that acts as a free radical scavenger (such as hydroquinone). It is known that it can be done.

[0005] However, although this method of fixing an original image has achieved dry development, it has to undergo wet development again, making the process complicated.

On the other hand, for example, DuPont
Pont) Dylux (registered trademark)
There are also commercially available photoimaging materials that do not require wet processing, such as forming an image with ultraviolet light and fixing with visible light by activating a photoreducing substance. However, this method has disadvantages in that the time required to use the developing device is longer because the light is used twice, and the processing speed is slower because it requires operations such as replacing spectral filters.

Furthermore, in the above-mentioned Japanese Patent Publication No. 43-29,407, a reducing heat fixing agent is included in the binder solution together with a leuco dye and a photooxidizing agent, or the fixing agent is overcoated on the photosensitive layer. There is a description that heat fixing is performed after image exposure. However, in this method, sensitivity deteriorates over time because the photosensitive material (leuco dye and photooxidizer) and fixing agent coexist in close proximity.
The drawback was that it was not realistic.

[0008] Photoimage-forming materials comprising these leuco dyes and photooxidizing agents are usually uniformly dissolved in an organic solvent and coated (or dipped or coated) on a support such as paper or plastic film.
After casting), the solvent is removed by evaporation by drying. Therefore, the use of such a volatile solvent requires explosion-proof measures for manufacturing equipment, etc., which is disadvantageous from both safety and manufacturing cost standpoints.

In order to solve the above-mentioned drawbacks, the present inventors have already developed a method in which "at least one selected from leuco dyes capable of developing color by oxidation and at least one selected from photo-oxidizing agents are both encapsulated in microcapsules." A photoimage-forming material characterized in that, on the outside of the microcapsules, at least one reducing agent selected from reducing agents is dissolved in an organic solvent that is insoluble or sparingly soluble in water and then emulsified and dispersed. ” (Japanese Patent Application No. 62-287096).

0010

[Problems to be Solved by the Invention] However, with the above-mentioned photoimage-forming materials, when water adheres to the photoimage-forming layer, the photoimage-forming layer peels off from the support (water resistance is insufficient), and the photoimage-forming layer is not transparent. Because of the insufficient properties, when images are recorded and heat-fixed using transparent films for OHP, etc., the projected images have insufficient clarity.

[0011] The inventors of the present invention have made extensive studies to solve the above-mentioned drawbacks and have found that good results can be obtained by providing a protective layer containing silicone resin as a main component on the photoimage forming layer. We have reached the main headline. Therefore, an object of the present invention is to provide a photoimage-forming material having excellent water resistance and transparency.

0012

[Means for Solving the Problems] The above objects of the present invention are as follows:
A support, microcapsules containing both a leuco dye capable of oxidative color development and a photooxidizing agent, and an emulsion or reducing agent obtained by dissolving the reducing agent in an organic solvent that is insoluble or sparingly soluble in water and then emulsifying and dispersing it. A photoimage forming layer formed by coating and drying a coating solution containing one of the microcapsules on the support, and one or more protective layers provided on the photoimage forming layer. This was achieved by a photoimage-forming material characterized in that at least one of the protective layers contains a silicone resin as a main component.

[0013] Leuco dyes that can be used in the present invention are those having one or two hydrogen atoms that form a dye and develop color by adding or removing additional electrons. It means a reduced form of dye. In the present invention, by selecting a substantially colorless or light-colored leuco dye,
It can be colored by photooxidation and form clear images.

The leuco dye that is oxidized and colored by a photooxidizing agent used in the present invention is disclosed in, for example, US Pat. No. 3,445,2
No. 34, specific examples include (1)
aminotriarylmethane, (2) aminoxanthene,
(3) aminothioxanthene, (4) amino-9,10
-dihydroacridine, (5) aminophenoxazine,
(6) aminophenothiazine, (7) aminodihydrophenazine, (8) aminodiphenylmethane, (9) leucoindamine, (10) aminohydrocinnamic acid (
cyanoethane, leucomethine), (11) hydrazine,
(12) Leuco indigoid dye, (13) Amino-2
, 3-dihydroanthraquinone, (14) tetrahalo-
p,p'-biphenol, (15) 2-(p-hydroxyphenyl)-4,5-diphenylimidal, (16
) phenethylaniline and the like.

Among these leuco dyes, (1) to (9)
) loses one hydrogen atom to develop color and becomes a dye, while compounds (10) to (16) lose two hydrogen atoms to form a dye.

Among these, aminotriarylmethane is particularly preferred in the present invention. Regarding such aminotriarylmethane, Japanese Patent Application No. 62-28709
Details are given in issue 6.

The photooxidizing agent used in the present invention is activated by irradiation with light and reacts with the leuco dye to form a colored image on the background of the unchanged material. Such photooxidants are compounds that are inactive until exposed to actinic light such as visible light, ultraviolet light, infrared light, X-rays, and the like.

The various photooxidants that can be used in the present invention have different peak sensitivities across the spectrum, depending on the structure of the compound. That is, by being exposed to a specific active light, the photo-oxidizing agent contained in the microcapsules that absorbs the light becomes an active oxidizing agent, and the leuco dye contained in the microcapsules becomes an active oxidizing agent. It oxidizes and develops color, so a colored image is formed in the area irradiated with light.

Specific examples of such photo-oxidizing agents include those described in US Pat. Nos. 3,042,515 and 3,502,4.
Halogenated hydrocarbons such as carbon tetrabromide, N-bromosuccinimide, and tribromomethylphenylsulfone described in No. 76, azide polymers described in the Abstracts of the 1968 Spring Research Presentation of the Photographic Society of Japan, page 55, the United States Azide compounds such as 2-azidobenzoxazole, benzoyl azide, and 2-azidobenzimidazole described in U.S. Pat. No. 3,282,693, U.S. Pat. No. 3,615
, 568, 3'-ethyl-1-methoxy-
2-pyridothiacyanine perchlorate, 1-methoxy-2-methylpyridinium-p-toluenesulfonate, 2,4,5 described in Japanese Patent Publication No. 62-39,728
Examples include lophine dimer compounds such as -triarylimidazole dimer, benzophenone, p-aminophenyl ketone, polynuclear quinone, thioxanthenon and mixtures thereof.

In the present invention, the molar ratio of the amount of the leuco dye to the amount of the photooxidizing agent is 10:1.
It is preferable to mix at a ratio of ~1:10, especially 2:1~1
: It is preferable to mix at a ratio of 2.

In the present invention, known sensitizers and stabilizers such as known antioxidants may be added to the microcapsules as additional components of the photo-oxidizing agent. These are described in detail in Japanese Patent Application No. 62-287096.

In the photoimage-forming material of the present invention, after forming an image by imagewise irradiation, for example, by heating,
The image can be made stable and reliable (referred to as image fixation). That is, when the photoimage-forming material after image formation is heated, the microcapsules contained in the photoimage-forming layer become permeable to substances, and the photooxidizing agent and reducing agent, which were separated by the microcapsule wall, come into contact with each other. This is to deactivate the photo-oxidizing agent.

The reducing agent used in the present invention is a so-called free radical trapping substance that traps the free radicals of the activated photo-oxidizing agent, and has the effect of deactivating the oxidizing action of the photo-oxidizing agent. Therefore, even if the photoimage-forming material is irradiated with actinic rays after heating, the leuco dye is no longer oxidized by the photooxidizing agent.

[0024] The above-mentioned free radical scavenging substance can be appropriately selected from known substances. Specifically, for example, an organic compound having a hydroxyl group on a benzene ring and at least another hydroxyl group or an amino group at another position on the benzene ring, as described in U.S. Pat. No. 3,042,515, Reducing agents (e.g. hydroquinone,
Catechol, resorcinol, hydroxyhydroquinone, pyrrologlycinol and o-aminophenol, p
-aminophenols such as aminophenol), cyclic phenylhydrazide compounds described in Japanese Patent Publication No. 62-39,728, such as 1-phenylpyrazolidine-3-
on [phenidone A, (chemical formula 1)],

[0025]

[Chemical formula 1] 1-phenyl-4-methylpyrazolidin-3-one [Phenidone B, (Chemical formula 2)],

[Chemical formula 2] 1-phenyl-4,4-dimethylpyrazolidin-3-one [dimezone, (Chemical formula 3)],

[Chemical formula 3]

3-Methyl-1-(p-sulfophenyl)
-2-pyrazolin-5-one and 3-methyl-1-phenyl-2-pyrazolin-5-one, JP-A-57-132
, 141 (for example, 1-
3-diphenylguanidine, phenylguanidine, 1,
3-di-o-tolylguanidine, 1-o-tolyl biguanide, 1-benzylidene-guanidinoamino), alkylene diamine compounds (e.g. ethylenediamine, propylene diamine, tetramethylene diamine, hexamethylene diamine, octamethylene diamine), hydroxyamine compounds (For example, diethanolamine, triethanolamine) and the like.

However, on the phenyl group of the cyclic phenylhydrazide, o-, m- and p-methyl, p-trifluoromethyl, m- and p-chloro, m- and p-bromo, p-fluoro, Substituents such as o-, m- and p-methoxy, p-ethoxy, p-benzyloxy, p-butoxy, p-phenoxy, 2,4,6-trimethyl and 3,4-dimethyl may be present. .

Further, substituents such as bis-hydroxymethyl, hydroxymethyl and methyl, dimethyl, dibutyl, ethyl and benzyl groups can also be present at the 4-position on the heterocyclic group of the cyclic phenylhydrazide. Furthermore, dimethyl,
Methyl or phenyl can also be present.

The above reducing agents may be used alone or in combination of two or more. Further, any reducing substance that can act on the oxidizing agent can be used without being limited to the above-mentioned reducing agent. The reducing agent can be used in an amount of 1 to 100 mol per 1 mol of the photo-oxidizing agent, but generally 1 to 10 mol is sufficient. In addition to the heating described above, the image of the present invention can be fixed by destroying the microcapsules by applying pressure or applying pressure and heating and bringing the photooxidizing agent and the reducing agent into contact with each other.

[0030] In the present invention, not only is the photo-oxidizing agent and the reducing agent separated, but also the viewpoint of improving the transparency of the photo-image forming layer and the raw storage property such as preventing contact between the photo-oxidizing agent and the reducing agent at room temperature are achieved. From the viewpoint of preventing fogging, the photo-oxidizing agent and the leuco dye are encapsulated in microcapsules and the reducing agent is used in the form of an emulsified dispersion, or the photo-oxidizing agent and the leuco dye and the reducing agent are used separately. It is used by encapsulating it in microcapsules.

Any of the interfacial polymerization method, internal polymerization method, and external polymerization method can be used to produce the microcapsules used in the present invention, but in particular, leuco dye and photooxidizing agent or reducing agent It is preferable to employ an emulsion polymerization method in which a core material containing .

[0032] A reactant forming a polymeric substance is added to the interior of the oil droplet and/or to the exterior of the oil droplet. Specific examples of the polymeric material include polyurethane, polyurea, polyamide, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene-methacrylate copolymer, styrene-acrylate copolymer, and the like. Preferred polymeric materials are polyurethanes, polyureas, polyamides, polyesters, polycarbonates, particularly preferred are polyurethanes and polyureas. Two or more types of polymeric substances can also be used in combination.

Specific examples of the water-soluble polymer include gelatin, polyvinylpyrrolidone, polyvinyl alcohol, and the like. For example, when polyurea is used as a capsule wall material, polyisocyanates such as diisocyanates, triisocyanates, tetraisocyanates, and polyisocyanate prepolymers, polyamines such as diamines, triamines, and tetraamines, and two amino groups are used. A microcapsule wall can be easily formed by reacting the prepolymer, piperazine or its derivative, polyol, etc. contained above in an aqueous solvent by an interfacial polymerization method.

[0034] Furthermore, for example, a composite wall made of polyurea and polyamide or a composite wall made of polyurethane and polyamide can be formed by using, for example, polyisocyanate and acid chloride, or polyamine and polyol, after adjusting the pH of the emulsifying medium serving as the reaction liquid. It can be prepared by heating. For details on the manufacturing method of these composite walls made of polyurea and polyamide, please refer to JP-A-58-6
It is described in Japanese Patent No. 6948.

Furthermore, metal-containing dyes, charge control agents such as nigrosine, or other optional additives can be added to the microcapsule walls used in the present invention, if necessary. These additive substances can be incorporated into the capsule wall during wall formation or at any other time.

[0036] Furthermore, in order to adjust the chargeability of the surface of the capsule wall, if necessary, monomers such as vinyl monomers may be graft-polymerized, or these polymers may be attached. Furthermore, a solid sensitizer can be added to swell the microcapsule walls upon heating.

[0037] The solid sensitizer can be selected from those called plasticizers for the polymer used as the microcapsule wall, and has a melting point of 50°C or higher, preferably 120°C or lower, and is solid at room temperature. . For example, when the wall material is made of polyurea or polyurethane, hydroxy compounds, carbamate ester compounds, aromatic alkoxy compounds, organic sulfonamide compounds, aliphatic amide compounds, aryl amide compounds, etc. are preferably used.

In the present invention, when the reducing agent is not encapsulated in microcapsules, the reducing agent is dissolved in an organic solvent that is sparingly soluble or insoluble in water, and then dissolved in a water-soluble highly water-soluble solution containing a surfactant. The molecules are mixed with an aqueous phase having them as protective colloids and used in the form of an emulsified dispersion.

The organic solvent used in this case can be appropriately selected from high boiling point oils. In addition to esters, preferred oils include dimethylnaphthalene, diethylnaphthalene, diisopropylnaphthalene, dimethylbiphenyl, diethylbiphenyl, diisopropylbiphenyl, diisobutylbiphenyl, 1-methyl-1-dimethylphenyl-1-phenylmethane, 1-
ethyl-1-dimethylphenyl-1-phenylmethane,
1-propyl-1-dimethylphenyl-1-phenylmethane, triallylmethane (e.g. tritolylmethane, tolyldiphenylmethane), terphenyl compounds (
terphenyl), alkyl compounds (e.g. terphenyl), alkylated diphenyl ethers (e.g. propyl diphenyl ether), hydrogenated terphenyl (e.g.
Examples include hexahydroterphenyl), diphenyl ether, and the like. Among these, it is particularly preferable to use esters from the viewpoint of emulsion stability of the emulsified dispersion.

Examples of esters include phosphate esters (for example, triphenyl phosphate, tricresyl phosphate, butyl phosphate, octyl phosphate, cresyl diphenyl phosphate), phthalate esters (dibutyl phthalate, 2-ethylhexyl phthalate, phthalate). ethyl, octyl phthalate, butyl benzyl phthalate), dioctyl tetrahydrophthalate, benzoic acid ester (ethyl benzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, benzyl benzoate), abietic acid ester (ethyl abietate, benzyl abietate), dioctyl adipate,
Isodecyl succinate, dioctyl azelaate, oxalate esters (dibutyl oxalate, dipentyl oxalate)
, diethyl malonate, maleate esters (dimethyl maleate, diethyl maleate, dibutyl maleate)
, tributyl citrate, sorbate esters (methyl sorbate, ethyl sorbate, butyl sorbate), sebacate esters (dibutyl sebacate, dioctyl sebacate), ethylene glycol esters (formic acid monoesters and diesters, butyric acid monoesters and diesters, lauric acid monoesters and diesters, palmitic acid monoesters and diesters, stearic acid monoesters and diesters, oleic acid monoesters and diesters), triacetin, diethyl carbonate, diphenyl carbonate, ethylene carbonate, propylene carbonate, boric acid esters tributyl acid, tripentyl borate), etc. Among these, when tricresyl phosphate is used alone or in combination, the emulsification and dispersion stability of the reducing agent is particularly good, and therefore it is preferable.

[0041] It is also possible to use the above oils together or in combination with other oils. In the present invention, an auxiliary solvent may be added to the above-mentioned organic solvent as a low boiling point dissolution aid. Particularly preferred examples of such co-solvents include ethyl acetate, isopropyl acetate, butyl acetate and methylene chloride.

The water-soluble polymer to be contained as a protective colloid in the aqueous phase to be mixed with the oil phase containing these components is appropriately selected from known anionic polymers, nonionic polymers, and amphoteric polymers. However, polyvinyl alcohol, gelatin, cellulose derivatives, etc. are preferred.

[0043] The surfactant to be contained in the aqueous phase may be appropriately selected from anionic or nonionic surfactants that do not interact with the protective colloid to cause precipitation or aggregation. can. Preferred surfactants include sodium alkylbenzene sulfonate, sodium alkyl sulfate, dioctyl sodium sulfosuccinate, polyalkylene glycol (eg, polyoxyethylene nonylphenyl ether), and the like.

[0044] The emulsified dispersion in the present invention is produced by combining an oil phase containing the above components and an aqueous phase containing a protective colloid and a surfactant using means commonly used for fine particle emulsification, such as high-speed stirring and ultrasonic dispersion. It can be mixed and dispersed easily.

[0045] The ratio of the oil phase to the aqueous phase (oil phase weight/aqueous phase weight) is preferably from 0.02 to 0.6, particularly from 0.02 to 0.6.
．． It is preferable that it is 1-0.4. If it is less than 0.02, the aqueous phase is too large and diluted, and sufficient color development cannot be obtained;
．． On the contrary, if it is 6 or more, the viscosity of the liquid increases, resulting in inconvenience in handling and decreased stability of the coating liquid.

When coating the mixture of the emulsion dispersion liquid and microcapsule liquid prepared as described above (hereinafter referred to as photoimage forming layer liquid) on a support, a known water-based or organic solvent-based coating liquid may be used. A coating method described below using a coating method is used.

In this case, in order to safely and uniformly apply the photoimage forming layer liquid and to maintain the strength of the coating film, in the present invention, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, starches, gelatin, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, polyacrylamide,
Polystyrene and copolymers thereof, polyester and copolymers thereof, polyethylene and copolymers thereof, epoxy resins, acrylate and methacrylate resins and copolymers thereof, polyurethane resins, polyamide resins, etc. may be used together with microcapsules. can.

In order to produce the photoimage-forming material of the present invention, a coating solution containing the above-mentioned binder and other additives is prepared in the above-mentioned photoimage-forming layer solution, and applied onto a support such as paper or a synthetic resin film. Bar application, blade application, air knife application,
A photoimage forming layer having a solid content of 3 to 30 g/m2 is provided by coating and drying by a coating method such as gravure coating, roll coating, spray coating, or dip coating. The photoimageable layer provided in this manner has extremely good transparency.

The support used in the present invention may be transparent or opaque, but when used as a photoimage-forming material for OHP etc., a transparent support is used as a photoimage-forming material for printouts. If so, use an opaque support. It is preferable that the transparent support has high transparency and dimensional stability without being deformed by heating or pressure during fixing. The thickness of the support used is 10 μm to 200 μm.

Examples of such transparent supports include:
Polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate films, polyolefin films such as polystyrene films, polypropylene films, and polyethylene films, polyimide films, polyvinyl chloride films, polyvinylidene chloride films,
Examples include polyacrylic film and polycarbonate film, and these can be used alone or in combination.

On the other hand, examples of the opaque support of the recording material include paper, synthetic paper, aluminum vapor-deposited base, and the transparent support coated with a pigment or the like. The paper used for the support is a heat-extracted neutral paper with a pH of 6 to 9 sized with a neutral sizing agent such as an alkyl ketene dimer (
The method described in JP-A-55-14281) is advantageous in terms of storage stability over time.

[0052] In order to prevent the coating liquid from penetrating into the paper, the Steckigt sizing degree/
(Weight in meters) 2 ≧3×10 −3 and paper having Bekk smoothness of 90 seconds or more is advantageous.

[0053] Also, as described in JP-A-58-136492, the optical surface roughness is 8 μm or less and the thickness is 40 to 75 μm.
m paper, density 0.9 g as described in JP-A No. 58-69097
/cm3 or less and paper with an optical contact ratio of 15% or more,
The Canadian standard freeness described in JP-A-58-69097 (
Paper made from pulp that has been beaten to 400 cc or more according to JIS P8121) to prevent coating liquid from seeping in.
JP-A No. 58-65695 discloses a method in which the glossy side of a base paper made by a Yankee machine is used as the coating surface to improve color density and resolution, and JP-A No. 59-35985 discloses a method in which corona is applied to base paper. Papers etc. which have been subjected to electrical discharge treatment to improve their suitability for application may also be used in the present invention and give good results. In addition to these, any support commonly used in the field of recording paper can be used as the support of the present invention.

In the present invention, in order to prevent the entire photoimage forming layer from peeling off from the support, before coating the photoimage forming layer liquid containing microcapsules on the support,
It is desirable to provide an undercoat layer on the support.

[0055] As the undercoat layer, acrylic ester copolymer, polyvinylidene chloride, SBR, water-based polyester, etc. can be used, and the film thickness is 0.1-0.
5 μm is desirable. The coating amount is preferably 1 to 20 g/m2, particularly preferably 3 to 10 g/m2.

The undercoat layer may deteriorate the image quality of the photoimage-forming layer if the undercoat layer swells due to water contained in the photoimage-forming layer when the photoimage-forming layer is coated thereon. Therefore, it is desirable to use a hardening agent to harden the film. Such hardeners are described in detail in, for example, JP-A-2-111585.

Furthermore, before applying the undercoat layer, it is desirable to activate the surface of the support by a known method. Activation treatment methods include acid etching treatment,
Flame treatment using a gas burner, corona treatment, glow discharge treatment, etc. are used, but from the point of view of cost or simplicity, US Pat. No. 2,715,075, US Pat.
No. 846,727, No. 3,549,406, No. 3
, 590, 107, etc., is most preferably used.

In the present invention, there are problems such as a decrease in apparent transparency due to light scattering on the surface of the photoimage forming layer, adhesion of the photoforming material to a heating roller etc. during heat fixing, and the possibility that the photoimage forming material is overlapped. Sometimes adhesion (blocking)
In order to prevent the photoimage forming layer from peeling off from the support (water resistance) when water is attached, a protective layer is provided on the photoimage forming layer by a known method.

Details of the protective layer are described, for example, in "Paper and Pulp Technology Times" (September issue, 1985), pages 2 to 4, and in Japanese Patent Application No. 1987-287096. In the present invention, a protective layer containing a silicone resin as a main component is provided together with or in place of the above-mentioned protective layers conventionally used. Thereby, the water resistance can be significantly improved without impairing the transparency of the photoimage forming layer.

The silicone resin used in the protective layer may be one having a siloxane bond as its main chain, but these include alkyl groups, phenyl groups, carboxyl groups, vinyl groups, nitrile groups, alkoxy groups, chlorine atoms, etc. It may be replaced with .

In addition to the above silicone resin, melamine resin, phenol resin, acrylic resin, polyester resin, epoxy resin, fluororesin, nitrocellulose, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate, vinylidene fluoride,
Other non-aqueous resins such as chlorinated rubber may also be used. Waxes and metal soaps can also be added to the protective layer. The amount of these used is 0.2 to 7 g/m2.

[0062] The light source for exposure to form an image on the photoimage-forming material produced as described above of the present invention is not particularly limited, and may be natural light, artificial light, monochromatic light, non-coherent light or Any type of light such as coherent light can be used. However, in order to form an appropriate image, it is necessary to select a light source with an appropriate light wavelength and light density that corresponds to the photoimageable composition. Such light sources are described in detail in Japanese Patent Application No. 62-287096.

[0063]

Effects of the Invention As detailed above, the photoimage-forming material of the present invention has a layer containing a silicone resin as a main component as a protective layer, so that water resistance can be improved without impairing the transparency of the photoimage-forming layer. Significantly improved.

[0064]

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto. Note that "parts" representing the amount added represent "parts by weight."

Example 1. Preparation of capsule liquid

[Table 1] ──────────────────────────
──────────── Leuco dye

1.5 parts (leuco crystal violet) Photooxidizer

3.0 parts (2,2'-bis-(o-chlorophenyl)-4,4',5,5'-tetraphenylbimidazole)methylene chloride

12-part tricresyl phosphate

24 parts Takenate D-110N (75% by weight ethyl acetate solution) 24 parts (trade name of microcapsule wall agent manufactured by Takeda Pharmaceutical Co., Ltd.)
──────────────────────────
────

[0066] A liquid mixture of the components listed above (Table 1) was added to an aqueous solution of 8% by weight polyvinyl alcohol and 100 parts of distilled water, and then emulsified and dispersed at 20°C to obtain an average particle size of 1 μm. An emulsified dispersion was obtained. The obtained emulsified dispersion was stirred at 40° C. for 3 hours and encapsulated to obtain a capsule liquid.

Preparation of reducing agent emulsion dispersion Phenidone A (1-phenylpyrazolidin-3-one)
42g was dissolved in 8g of diethyl maleate and 30g of ethyl acetate. The obtained solution was mixed with an aqueous solution of 100 g of an 8% by weight polyvinyl alcohol aqueous solution, 150 g of water, and 0.5 g of sodium dodecylbenzenesulfonate, and was mixed with an aqueous solution of 100 g of an 8% by weight polyvinyl alcohol aqueous solution, and 0.5 g of sodium dodecylbenzenesulfonate.
Emulsify at 0,000 rpm for 5 minutes at room temperature to obtain a particle size of 0.5
A reducing agent emulsion dispersion of μm size was obtained.

Preparation of photoimage-forming material 9 parts of the capsule liquid and 7 parts of the reducing agent emulsified dispersion were mixed to obtain a photoimage-forming layer liquid. The obtained photoimage forming layer liquid was placed on a polyethine terephthalate sheet with a thickness of 75 μm.
A photoimage forming layer was formed by spin coating at a rotational speed of 50 rpm, and then heated and dried at 50° C. for 1 minute. Next, silicone resin (Toray Silicone SR2411: trade name manufactured by Toray Industries, Inc.) was applied onto the photoimage forming layer at a solid content of 2.5 g/m2.
2 to form a protective layer.

The resulting photoimage-forming material had good transparency and satisfactory water resistance. In addition, each evaluation was performed as follows. Transparency: Haze (turbidity) was measured using an integrating sphere haze meter. Water resistance: Evaluated by dropping water droplets on the photoimage forming layer, rubbing with fingers, and observing how the coated layer peels off.

Example 2. Instead of Toray Silicone SR2411 used in Example 1, Toray Silicone SR
A photoimage-forming material was obtained in exactly the same manner as in Example 1, except that a mixture of SR2411 and SR2410 at a ratio of 10:1 was used. The transparency and water resistance of the obtained photoimage-forming material were as good as in Example 1.

Comparative Example 1. A photoimage-forming material was prepared and evaluated in exactly the same manner as in Example 1, except that Toray Silicone SR2411 used in Example 1 was coated with the components shown below (Table 2).

[0072]

[Table 2] ──────────────────────────
────────Polyvinyl alcohol

1 part by weight (PVA-124: trade name manufactured by Kuraray Co., Ltd.) Zn stearate dispersion
0.1 part by weight (Hydrin Z-7: trade name manufactured by Chukyo Yushi Co., Ltd.)────
──────────────────────────
───

The resulting photoimage-forming material had good transparency but was completely unsatisfactory in water resistance. Comparative example 2. Toray Silicone SR2 used in Example 1
A photoimage-forming material was prepared in exactly the same manner as in Example 1, except that the components listed below (Table 3) were applied instead of 411.
evaluated.

[0074]

[Table 3] ──────────────────────────
───────Silicon-modified polyvinyl alcohol
0.5 parts by weight (
PVAR-2105: Colloidal silica (product name manufactured by Kuraray Co., Ltd.)
0.5 parts by weight (Snowtex 30: trade name manufactured by Nissan Chemical Co., Ltd.) Zn stearate dispersion
0.1 part by weight (Hydrin Z-7
:Product name manufactured by Chukyo Yushi Co., Ltd.) ────────
────────────────────────

[
The obtained photoimage-forming material had good transparency but was insufficient in water resistance. Comparative example 3. Toray Silicone SR2 used in Example 1
A photoimage-forming material was prepared in exactly the same manner as in Example 1, except that the components listed below (Table 4) were applied instead of 411.
evaluated.

[0076]

[Table 4] ──────────────────────────
────────Silicon-modified polyvinyl alcohol
0.5 parts by weight (P
VAR-2105: Colloidal silica (product name manufactured by Kuraray Co., Ltd.)
0.5 parts by weight (Snowtex 30: trade name manufactured by Nissan Chemical Co., Ltd.) Kaolin

1 part by weight (
Kaoprite: trade name manufactured by Schiele Co., Ltd.) Zn stearate dispersion
0.2 parts by weight (Hydrin Z-7:
Product name manufactured by Chukyo Yushi Co., Ltd.) ──────────
────────────────────────

0
The resulting photoimage-forming material had low transparency and unsatisfactory water resistance. The results of the above examples and comparative examples are summarized in Table 5.

[0078]

[Table 5] ──────────────────────────
─ Transparency
Water resistance────────────────
────────────Example 1 Large
Good example 2
Big
Good comparative example 1 Large
Extremely bad comparative example 2 Large
Bad comparative example 3
small
Bad────────────────────────
──────

The above results demonstrate that by providing a layer containing silicone resin as a main component as a protective layer for the photoimage forming material, the transparency of the photoimage forming layer is not impaired.
This demonstrates that water resistance is improved.

Claims (1)

[Claims] Claim 1: An emulsion obtained by dissolving a support, a microcapsule encapsulating both a leuco dye capable of oxidative color development and a photooxidizing agent, and a reducing agent in an organic solvent that is insoluble or sparingly soluble in water and then emulsifying and dispersing the mixture; A photoimage-forming layer formed by coating and drying a coating solution containing one of microcapsules containing a reducing agent on the support, and one or more protective layers provided on the photoimage-forming layer. 1. A photoimage-forming material comprising: at least one layer of the protective layer containing a silicone resin as a main component.