JPH03204650A - Photosensitive material - Google Patents

Abstract

PURPOSE:To improve storage life by forming a photosensitive layer contg. photosensitive silver halide, a reducing agent, a polymer having ethylenic unsatd. double bonds in the side chain as a binder and a base or a precursor thereof but not practically contg. a polymerizable compd. on a substrate. CONSTITUTION:A photosensitive layer 12 contg. photosensitive silver halide, a reducing agent, a polymer having ethylenic unsatd. double bonds in the side chain as a binder and a base or a precursor thereof each in a uniformly dispersed state is formed on a substrate 11 to obtain a photosensitive material 10. Since a polymerizable compd. is not practically contained in the photosensitive layer 12, a hardened image is formed with the polymer binder. Spontaneous thermal polymn. by the addition polymn. reaction of an unsatd. double bond in the polymerizable compd. is prevented during storage and the storage life of the photosensitive material is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a photosensitive material that utilizes a polymerization reaction with silver halide. In particular, it relates to photosensitive materials that can be suitably used for printing plates.

[Background of the Invention] A method of imagewise exposing a photosensitive material containing a photosensitive silver halide, a reducing agent, and a polymerizable compound, developing the silver halide (liquid development), and polymerizing the material imagewise to form a polymer image. is described in Japanese Patent Publication No. 45-11149.

As an improvement on the above method, a method of forming a polymer image using a dry development process (thermal development process) is disclosed in JP-A-61-69062 or JP-A-61-73145. This method uses a recording material (photosensitive material) formed by carrying on a support a photosensitive layer comprising a photosensitive silver halide, a reducing agent, a polymerizable compound, and a binder or a color image forming substance. This is a method in which a latent image of silver halide is formed by exposure and then heated to form a polymer in the area where the latent image has been formed. Note that a method is already known in which a polymerizable compound can be polymerized in areas where a silver halide latent image is not formed (Japanese Patent Laid-Open Publication No. 70836/1983).

The photosensitive layer of the above photosensitive material usually contains a base or a base precursor. The base or base precursor has the function of accelerating the development of the silver halide as an image formation accelerator.

It is known that the above photosensitive material can be used as a printing plate (Japanese Patent Application Laid-Open No. 61-228441). The printing plate is made by subjecting the photosensitive material to imagewise exposure and thermal development, washing it with a liquid that dissolves the uncured portions of the photosensitive layer, and removing (etching) the uncured portions of the photosensitive layer to form an image-like polymer image (relief). It is manufactured by a method consisting of a step of forming. As the liquid (etching liquid) for elution and removal, an organic solvent is generally used.

[Problems to be Solved by the Invention] Inventor Ki further conducted research on photosensitive materials suitable for printing plates. As a result, it was found that the polymerizable compound (component), which is a component of the photosensitive layer, spontaneously polymerizes due to heat during storage of the photosensitive material, resulting in a decrease in its storage stability, which may pose a problem.

Further, when considering the etching solution, it is preferable to use an alkaline aqueous solution rather than an organic solvent from the viewpoint of safety and cost. Therefore, it is necessary to construct the photosensitive layer so that it can be dissolved in an alkaline aqueous solution.

In addition, when producing a printing plate from a photopolymer-based (photopolymerization-based or diazo-based) photosensitive material or the photosensitive material described in JP-A-58-121031, it is necessary to use a photosensitive material that has an acidic group in the molecule and It is known that the above-mentioned etching can be carried out in an alkaline aqueous solution by using a binder polymer that is soluble in the alkaline aqueous solution.

However, when the binder polymer soluble in the above alkaline aqueous solution is used, the acidic groups contained in this molecule are neutralized with the base (or the base generated by thermal decomposition of the base precursor), resulting in halogenation. It has also been found that there is a problem in that silver development does not occur sufficiently and, therefore, it is difficult to form a polymerized image.

[Object of the Invention] An object of the present invention is to solve the above-mentioned problems and provide a photosensitive material that has high sensitivity and high mechanical strength of the image and can be passed through a printing plate.

That is, an object of the present invention is to provide a photosensitive material that can be passed through a printing plate and has sufficient printing durability without using a polymerizable compound (monomer).

Another object of the present invention is to provide a photosensitive material from which a printing plate can be produced using an alkaline aqueous solution as an etching solution.

The present invention provides photosensitive silver halide, a reducing agent,
Contains a binder polymer having an ethylenically unsaturated double bond in the side chain, and a base or base precursor,
A photosensitive material having a photosensitive layer substantially free of polymerizable compounds is provided.

Further, the present invention provides a mixture of a binder polymer having an ethylenically unsaturated double bond in the side chain and a binder polymer having an acidic group, or having an ethylenically unsaturated double bond in the side chain, on the support, and a second layer comprising a binder polymer having an acidic group, and a second layer comprising a base or a base precursor and a water-soluble binder polymer having no acidic groups thereon, and a photosensitive silver halide and a reducing agent are , a photosensitive material contained in any of the layers thereof is provided.

Preferred embodiments of the photosensitive material of the present invention are described below.

(1) The binder polymer having an ethylenically unsaturated double bond in its side chain is a copolymer, and the molar content of the comonomer having an ethylenically unsaturated double bond in its side chain with respect to the copolymer is at least 10 mol% (more preferably 50 mol%) or more.

(1-2) The binder polymer having an ethylenically unsaturated double bond in its side chain contains allyl (meth)acrylate and/or vinyl (meth)acrylate copolymer.

1-3) The amount of the binder polymer having an ethylenically unsaturated double bond in the side chain is 10 to 9 with respect to the total amount of the photosensitive layer.
Contains 5% by weight.

(1-4) The photosensitive silver halide and the base or base precursor are contained in the second layer.

■-5) Layer thickness (dry film thickness) of the above first layer, 0.3~
It is in the range of 7 μm.

■-6) Thick dry film of the second layer N) or 0.5 to 2
It is in the range of 0 μm.

1-7) The base precursor contained in the second layer is
The base is released in a temperature range of 50°C to 200t.

(1-8) The support is an aluminum support.

■-1) Having an ethylenically unsaturated double bond in the above side chain,
In addition, the binder polymer having an acidic group is a copolymer containing a vinyl binder having an ethylenically unsaturated double bond in a side chain and a vinyl binder having an acidic group.

■-2) Having an ethylenically unsaturated double bond in the above side chain,
and the binder polymer having an acidic group is a copolymer containing a vinyl compound having an ethylenically unsaturated double bond in a side chain and a vinyl compound having an acidic group,
The molar content of monomers having double bonds in the copolymer is in the range from 30 to 98%, and the content of monomers having acidic groups is in the range from 1 to 50%.

II-3) In the second layer, the binder polymer having an ethylenically unsaturated double bond in the side chain and having an acidic group contains 10 of the total binder polymers contained in the first layer. It is contained in a proportion ranging from 100% by weight.

■-4) The total binder polymer in the first layer is 0.
．． It is included in an amount ranging from 1 to 7 g/rn'.

■-5) The layer thickness (dry film thickness) of the first layer is 0.3 to
It is in the range of 7 μm.

1l-6) The second layer contains a binder polymer having no acidic groups in an amount ranging from 0.1 to 10 g/rn'.

■-7) The base precursor contained in the second layer,
It releases the base in the temperature range of 50°C to 200°C.

n-5) The dry film thickness of the second layer is 0.5 to
It is in the range of 20 μm.

1l-9) The support is an aluminum support.

[Effects of the Invention] The photosensitive material of the present invention does not substantially contain a polymerizable compound (monomer). The cured image area (polymer image area) is formed by a binder polymer having an ethylenically unsaturated double bond in its side chain (the unsaturated double bond in the polymer causes an addition polymerization reaction). Therefore, unlike in the case of using sentsumar, the photosensitive material does not undergo spontaneous polymerization due to heat during storage, making it possible to provide a photosensitive material that is stable in terms of storage stability.

Further, according to the present invention, by forming a multilayer structure in which the layer provided on the support is divided into upper and lower layers, the following effects can be obtained in addition to the above effects.

1゜The first layer is mainly composed of a binder polymer having ethylenically unsaturated double bonds in its side chains (in particular, components involved in image forming reactions such as silver halide and reducing agents are In embodiments that are not included in one layer, it consists mostly of polymer only). Therefore, a polymer image having greater mechanical strength than the photosensitive material of the present invention in which each component is uniformly contained in the photosensitive layer is formed.

2o If an oil-based polymerizable compound is used in the first layer,
However, since the first layer is composed of the above-mentioned specific binder polymer, the second layer can be applied well. can be set.

In a photosensitive material in which a binder polymer having 3° acidic groups is introduced into the photosensitive layer, the base or base precursor is separated from the binder polymer having acidic groups present in the first layer, and the base or base precursor is separated from the binder polymer having acidic groups present in the first layer. is bound to the polymer.

Therefore, the acidic group is difficult to diffuse into the second layer containing the base or base precursor, and the base is difficult to be neutralized by the acid. In addition, the base (or the base generated from the base precursor) promotes the development of silver halide, on which a latent image has been formed by exposure, with a reducing agent and the subsequent generation of radicals. This occurs in the second layer, depending on the position in which it is placed, but particularly in embodiments in which photosensitive silver halide is contained in the second layer. Therefore, the image forming reaction occurs efficiently without being substantially inhibited by the acidic group-containing polymer.

4゜In the case of an embodiment in which the photosensitive silver halide is contained in the second layer (upper layer) 1 Even if a coloring substance is added to the first layer, the sensitivity of the silver halide is not inhibited. . However,
No decrease in sensitivity occurs.

5゜In general, base precursors may decompose little by little during storage of photosensitive materials, degrading the photosensitive silver halide and reducing agent, but binder polymers with acidic groups are used in the photosensitive layer (in the first layer). In a photosensitive material having a structure in which this acidic group is introduced, the acidic group is captured and neutralized, so that the storage stability of the photosensitive material is unlikely to deteriorate.

6° Since the second layer is on the upper side, oxygen in the air is difficult to diffuse into the first layer, and the influence of oxygen (polymerization inhibition effect) is alleviated. Therefore, the polymerization reaction occurs efficiently.

7. When a pigment is used in the first layer, if ethyl cellulose is included at the same time, aggregation of the pigment is significantly prevented and the pigment is easily finely dispersed. Therefore, a uniform colored layer can be obtained.

8. The light-sensitive material of the present invention has much higher photosensitivity than conventional photopolymer-based light-sensitive materials, and does not require wet processing in the silver development process unlike conventional light-sensitive materials using silver halide.

[Detailed Description of the Invention] The attached FIGS. 1, 2, and 3 show schematic cross-sectional views of the photosensitive material of the present invention. The following will explain using these.

The photosensitive material (10) shown in FIG.
It has a photosensitive layer (12) on top. The photosensitive layer (12) contains photosensitive silver halide, a reducing agent, a binder polymer having an ethylenically unsaturated double bond in its side chain, and a base or base precursor, and each component is in a uniformly dispersed state.

The photosensitive material (20) shown in FIG. 2 is a preferred embodiment of the photosensitive material shown in FIG. 1, and the photosensitive layer provided on the support (21) is layer (23
) and a second layer (24). A binder polymer having ethylenically unsaturated-heavy bonds in its side chains is included in the first layer (23). A photosensitive silver halide, a reducing agent and a base or base precursor are also included in the second layer (24). Note that the photosensitive silver halide, reducing agent, and base or base precursor can be included in the first layer (23), or these components can be divided into the first layer and the second layer. It can also be placed.

The photosensitive material (30) shown in FIG.
Above, a first layer (33) and a second layer (34) are provided in a layered configuration. A mixture of a binder polymer having an ethylenically unsaturated double bond in the side chain and a binder polymer having an acidic group, or a binder polymer having an ethylenically unsaturated double bond in the side chain and an acidic group is It is included in the first layer (33). A photosensitive silver halide, a reducing agent and a base or base precursor and a water-soluble binder polymer free of acidic groups are included in the second layer (34).

Note that the photosensitive silver halide and the reducing agent are contained in the third layer (3).
3) and the second layer (34).

The photosensitive material having the structure below]- contains substantially a polymerizable compound (
1,000,000 yen) is not included. Here, the polymerizable compound means, for example, a compound having addition polymerizability or ring-opening polymerizability. Examples of the addition polymerizable compound include compounds having an ethylenically unsaturated group, and examples of the ring-opening polymerizable compound include compounds having an epoxy group.

The photosensitive material (20) having the structure shown in FIG. 2 will be mainly explained below. Note that the optional components that can be included in each layer of the photosensitive material (20) having the structure shown in FIG. 2 (these will be described later) can also be included in the photosensitive material (30) having the structure shown in FIG. Can be used in a similar arrangement.

Supports include paper, synthetic paper, paper coated with synthetic resins (e.g. polyethylene, polypropylene, polystyrene, etc.), plastic films (e.g. polyethylene terephthalate, polycarbonate, polyimide, nylon, etc.).
films made of cellulose triacetate, etc.), metal plates (e.g., aluminum, aluminum alloys, zinc,
(plates of iron, copper, etc.), paper or plastic films laminated or vapor-deposited with the above metals, etc. are used.

In particular, when used in a lithographic printing plate, among the above supports, aluminum plates, polyethylene terephthalate films, polycarbonate films, paper, and synthetic paper are preferred. Also preferred is a composite sheet in which an aluminum sheet is pasted on a polyethylene terephthalate film, as described in Japanese Patent Publication No. 48-18327.

The paper support is described in JP-A-61-3797 and JP-A-61-112150.

These supports are subjected to surface treatments such as surface roughening treatment or surface hydrophilic treatment as necessary.

Surface treatment when using an aluminum plate as a support (
This will be explained below using the graining process as an example.

Surface treatment (graining treatment) includes an electrochemical graining method in which an aluminum plate is grained by applying an electric current in a hydrochloric acid or nitric acid electrolyte, and the surface of the aluminum is scratched with a metal wire. Mechanical graining methods such as the Brass d'Alein method, the Pole d'Alein method in which the aluminum surface is grained with a polishing ball and abrasive, and the Brass d'Alein method in which the surface is grained with a nylon brush and abrasive can be used alone or Surface treatment (graining treatment) is performed using a combination method.

Next, the aluminum plate that has been grained in this way is
Chemically etched by acid or alkali. An industrially advantageous method is etching with alkali. Examples of the alkaline agent include sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, sodium hydroxide, potassium hydroxide, and lithium hydroxide. The concentration of this alkaline solution is 1.
The range of 50% by weight, and the temperature of alkali treatment is 20~
The temperature range is preferably 100°C, and the amount of dissolved aluminum is 5
Conditions such that the amount is 20 g/rn' are preferable.

Additionally, pickling is usually performed to remove smut remaining on the surface after alkaline etching. Acids include nitric acid, sulfuric acid, phosphoric acid, chromic acid, fluorine,
Preferred is borofluoric acid.

Incidentally, after the electrochemical surface roughening treatment, a smut removal treatment is usually performed. This treatment method was published in Japanese Patent Application Laid-Open No. 53-1273.
As described in Japanese Patent No. 9, a method of contacting with sulfuric acid at a concentration of 15 to 65% by weight at a temperature of 50 to 90°C, or a method described in Japanese Patent Publication No. 4828123 is effective.

The aluminum support whose surface has been roughened as described above is
Anodizing treatment or chemical conversion treatment can be performed as necessary.

The anodizing treatment can be performed by a known method. Specifically, an anodic oxide film is formed on the aluminum surface by passing a direct or alternating current through the aluminum in a solution containing sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc. alone or in combination. do. The conditions for anodic oxidation vary depending on the electrolyte used, but numerically, the concentration of the electrolyte is 1 to 80% by weight, the temperature of the electrolyte is 5 to 70°C, and the current density is O, S to 60 ampere/
dd, voltage is preferably in the range of 1 to 100 V, and electrolysis time is preferably in the range of 10 to 100 seconds.

The anodic oxidation method includes a method of anodic oxidation in sulfuric acid at a high current density (British Patent No. 1412768), or a method of anodic oxidation using phosphoric acid as an electrolytic bath (U.S. Patent No. 3).
511661) is particularly preferred.

The anodized aluminum plate is further subjected to an alkali metal sinter treatment (for example, by immersion in an aqueous solution of sodium silicate) as described in U.S. Pat. Nos. 2,714,066 and 3,181,461. or U.S. Patent No. 386042
As described in No. 6, an undercoat layer made of hydrophilic cellulose (eg, carboxymethyl cellulose, etc.) containing a water-soluble metal salt (eg, zinc acetate, etc.) can also be provided.

The binder polymer having an ethylenically unsaturated double bond in the side chain contained in the first layer (23) is not particularly limited and various types can be used.

Specifically, the following can be mentioned.

(1) Allyl (meth)acrylate and other monomers copolymerizable with the (meth)acrylate (for example, monohydroxyalkyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, (2) a polymer produced by reacting (meth)acrylic acid chloride with a hydroxyethyl (meth)acrylate copolymer (3) maleic anhydride Polymer (4) produced by adding pentaerythritol triacrylate to a copolymer through half-esterification Polymer (5) produced by adding glycol mono(meth)acrylate through half-esterification (5) Polymer produced by reacting glycidyl (meth)acrylate with (meth)acrylic acid copolymer or crotonic acid copolymer (5) 6) Hydroxyalkyl (meth)acrylate copolymer, polyvinyl formal, polyvinyl butyral,
Addition of 1/l of 2,4-toluene diisocyanate and hydroxyalkyl (meth)acrylate to the polymer (7) hydroxyalkyl (meth)acrylate copolymer produced by reacting maleic anhydride or itaconic anhydride. It is possible to copolymerize with polymer (8) vinyl (meth)acrylate produced by reacting allyl glycidyl ether with polymer (8) (meth)acrylic acid copolymer produced by reacting the (meth)acrylate with allyl glycidyl ether. and other thousands of people (e.g.
Monohydroxyalkyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, (meth)
and (10) a polymer produced by reacting a hydroxyalkyl (meth)acrylate copolymer with N-methylolacrylamide.

The above polymers can be used alone or in combination as appropriate for the tool.

The molar content of the comonomer having an ethylenically unsaturated double bond in its side chain in the binder polymer (copolymer) is preferably at least 10 mol% (more preferably 50 mol%) or more.

In the present invention, allyl (meth)acrylate copolymer or vinyl (meth)acrylate copolymer is preferred. The molecular weight of the binder polymer is 10,000 to 50
Preferably, it is in the range of 10,000.

The above copolymer is, for example, JP-A No. 59-45979,
It can be obtained by the manufacturing method described in Publication No. 59-53836 or No. 59-71048. Incidentally, the above-mentioned polymer is described in JP-A-64-17047.

In the photosensitive material having the structure shown in FIG. 1 (each component contained in the photosensitive layer is in a uniformly dispersed state), the binder polymer having ethylenically unsaturated double bonds in the side chain is The content is preferably 10 to 95% by weight (more preferably 30 to 90% by weight) based on the total amount of .

The first layer (23) may also contain other optional binder polymers. The binder polymer that can be used can be selected from a wide variety of polymers. Specific examples include poly(meth)acrylate, polyvinyl butyral, polyvinyl formal, polyvinylpyrrolidone, polyvinyl acetate, vinyl acetate-ethylene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride.
Examples include vinylidene chloride copolymer, vinylidene chloride-acrylonitrile copolymer, chlorinated polyethylene, chlorinated polypropylene, polycarbonate, diacetylcellulose, cellulose acetate butyrate, triacetylcellulose, ethylcellulose, polyvinylpyridine, polyvinylimidazole, and the like. The molecular weight of the above binder polymer is preferably in the range of about 10,000 to 500,000.

The binder polymer having an ethylenically unsaturated double bond in its side chain is preferably contained in a proportion ranging from 10 to 100% by weight based on the total binder polymer contained in the first layer. More preferably 50 to 100% by weight
is within the range of

In the photosensitive material (30) having the structure shown in FIG. It is a mixture with a polymer having a group, or a polymer having an ethylenically unsaturated double bond in a side chain and an acidic group in the molecule.

Polymers with ethylenically unsaturated double bonds in their side chains are
The polymers mentioned above can be used.

The polymer having an acidic group in its molecule is preferably a homopolymer of a vinyl monomer having an acidic group or a copolymer of the homopolymer and a vinyl monomer not containing an acidic group. Examples of vinyl monomers having acidic groups include acrylic acid, methacrylic acid, styrene sulfonic acid and maleic anhydride. Furthermore, the vinyl monomer having an acidic group may be one in which an acidic group such as a carboxyl group or a sulfone group is introduced into a monomer that does not have an acidic group. The comonomer to be copolymerized with the vinyl monomer having an acidic group can be arbitrarily selected from copolymerizable vinyl monomers, and specific examples include:
(Meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hydroxyethyl (meth)acrylate, hensyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, vinyl acetate, styrene ,(
Examples include meth)acrylonitrile, vinyl chloride, and vinylidene chloride. The molar content in the copolymer of acidic groups is 1% or more, more preferably 5%.
That's all.

The mixing ratio (wt%) of the polymer having an ethylenically unsaturated double bond in the side chain and the polymer having an acidic group in the molecule is preferably in the range of 98:2 to 30:70. More preferably, the ratio is in the range of 90:10 to 50:50.

Examples of polymers that have ethylenically unsaturated double bonds in their side chains and acidic groups in their molecules include the aforementioned polymers that have ethylenically unsaturated double bonds in their side chains. A copolymer comprising a vinyl monomer that carries an acidic group and a vinyl monomer that attaches an acidic group is preferred. The copolymer may further contain as a third monomer a chimera having neither tylenically unsaturated double bond groups nor acidic groups.

In the present invention, the vinyl monomer constituting the polymer having an ethylenically unsaturated double bond group in the side chain is preferably allyl (meth)acrylate or vinyl (meth)acrylate.

Examples of the vinyl monomer having an acidic group include the above-mentioned mercury.

Further, the third polymer can be arbitrarily selected from the copolymerizable vinyl monomers listed as comonomers to be copolymerized with the acidic group-containing vinyl monomer described above.

The molecular weight of the above binder polymer is preferably in the range of about 10,000 to 500,000.

The molar content of double bonds in a copolymer containing a vinyl monomer having an ethylenically unsaturated double bond in the side chain and a vinyl monomer having an acidic group is 30
It is preferable that the content is in the range of 98% to 98%, and the content of the acid group-containing acid group is preferably in the range of 1 to 50%.

A mixture of a binder polymer having an ethylenically unsaturated double bond in the side chain and a binder polymer having an acidic group,
Alternatively, the binder polymer having an ethylenically unsaturated double bond and an acidic group in the side chain is 10 to 100% by weight based on the total binder polymer contained in the first layer.
Preferably, it is contained in a proportion within the range of . More preferably, it is in the range of 50 to 100% by weight.

The first layer (23) may be colored.

There are no particular restrictions on the coloring substance (colorant), and known pigments or dyes can be used. The colorant also has the function of an antihalation agent and is therefore preferably added to the first layer. It can also be added to the second layer (24) for the purpose of preventing irradiation.

Among these pigments, in addition to commercially available pigments, known pigments described in various literatures can be used. Regarding literature, Color Index (C, R,) Handbook, "Latest Pigment Handbook" (edited by Japan Pigment Technology Association, published in 1977), "Latest Pigment Application Technology J (CMC Publishing, published in 1986),"
"Printing Ink Technology J (CMC Publishing, published in 1984)
etc.

Types of pigments include black pigment, yellow pigment, orange pigment,
brown pigment, red pigment, purple pigment, blue pigment, green pigment,
Examples include fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, and isoindolinone pigments. For dyeing, lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, etc. can be used.

The pigment that can be used in the present invention may be used without surface treatment, or may be used after surface treatment. Surface treatment methods include methods of surface coating with resin or wax, methods of attaching surfactants, and reactive substances (for example, silane coupling agents, epoxy compounds, polyisocyanates, etc.)
Possible methods include bonding the pigment to the surface of the pigment. The above surface treatment method is described, for example, in the following documents.

[Properties and Applications of Metallic Soaps] (Saiwai Shobo), ``Printing Ink Technology J (CMC Publishing, published in 1984), ``Latest Pigment Application Technology'' (CMC Publishing, published in 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm.

The pigment can be introduced into the first layer by adding and dispersing it in the core layer coating solution. As a method for dispersing the pigment, known dispersion techniques used in ink production, toner production, etc. can be used. Dispersion machines include ultrasonic dispersion machines, sand mills, attritors, burr mills, super mills,
Examples include a ball mill, an impeller, a desparzer-1KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, please refer to "Latest Pigment Application Technology J.
(CMC Publishing, published in 1986).

Dyes can also be used as colorants. As dyes that are themselves colored substances, in addition to commercially available ones, known ones described in various literature (for example, "Dye Handbook" edited by the Organic Synthetic Chemistry Association, published in 1972) can be used. Examples include dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, and methine dyes.

The content of the colorant varies widely depending on its absorbance, but preferably ranges from about 0.1 to 30% by weight, based on the total amount of the first layer.

In addition, when a pigment is included as a coloring agent in the first layer, it is preferable to use ethyl cellulose as a binder polymer. By using ethyl cellulose, it is possible to finely disperse the pigment, resulting in a uniform colored layer. In this case, the molecular weight of ethylcellulose is preferably in the range of about 10,000 to 1,000,000, more preferably in the range of 50,000 to 500,000. Further, the amount of ethylcellulose added is preferably in the range of 5 to 200% by weight, more preferably 20 to 10% by weight based on the amount of pigment used.
It is in the range of 0% by weight.

The first layer (23) is prepared by dissolving and dispersing a binder polymer having an ethylenically unsaturated double bond in its side chain, another optional binder polymer, the colorant, etc. in a suitable organic solvent, and then forming a coating solution. It can be provided by preparing, coating and drying this on the above-mentioned support.

The thickness of the first layer is preferably in the range of 0.3 to 7 μm, more preferably in the range of 0.5 to 3 μm.

If the thickness of the layer is less than 0.3 μm, the polymer image layer will be too thin and the printing durability will be reduced, and if it is more than 7 μm, it will be difficult to cure the first layer sufficiently to the bottom surface. The amount of binder polymer applied is
As can be calculated from the above mixing ratio and layer thickness, the total binder polymer is preferably in the range of 0.1 to 7 g/rn2, more preferably in the range of 0.3 to 3 g/rn'.

In the case of a photosensitive material having the structure shown in FIG. 3, a polymer having an ethylenically unsaturated double bond in its side chain is used instead of a binder polymer having an ethylenically unsaturated double bond in its side chain. A mixture with a polymer having an acidic group or a binder polymer having an ethylenically unsaturated double bond in a side chain and having an acidic group is used.

The second layer (24) contains photosensitive silver halide, a reducing agent,
Contains a base or base precursor.

Any grains of silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide, and silver chloroiodobromide can be used as the silver halogide.

Silver halide grains include those with regular crystal shapes such as cubes, octahedrons, and dodecahedrons, those with irregular crystal shapes such as spherical and plate shapes, and those with crystal defects such as twin planes. or a combination thereof.

The grain size of the silver halide may be as fine as about 0.01 microns or less, or as large as up to about 10 microns in projected area diameter. Further, it may be a polydisperse emulsion or a monodisperse emulsion as described in U.S. Pat. No. 3,574,628, U.S. Pat.

Tabular grains having an aspect ratio of about 5 or more can also be used. Tabular grains are described in the book by Gatoff, Photographic Science and Engineering (Cu.
toff, Photographic 5ci-en
ce and Engineering), No. 14
Vol. 248-257 (1970): U.S. Patent No. 44
No. 34226, No. 4414310, No. 4433048
No. 4439520 and British Patent No. 211215
It can be easily prepared by the method described in No. 7, etc.

The crystal structure may be --like, the inside and outside may have different halogen compositions, or it may have a layered structure. Further, silver halides having different compositions may be bonded by epitaxial bonding, or compounds other than silver halide such as silver rhodan or lead oxide may be bonded.

Furthermore, two or more types of silver halide grains different in halogen composition, crystal habit, grain size, etc. can also be used together.

The photosensitive silver halide is preferably used in the form of an emulsion.

Silver halide emulsions that can be used in the present invention are, for example, those published in Research Disclosure (RD) Magazine, Yang, 17643.
(December 1978), pp. 22-23, ■, Emulsion preparation and
18716 (19
(November 1979), p. 648.

The silver halide emulsion used is usually one that has been subjected to physical ripening, chemical ripening and spectral sensitization. Additives used in such processes are listed in Research Disclosure Magazine,
No. 17643 and No. 18716. Regarding chemical sensitizers, see Tsutomu, 17643 (p. 23) and Nao.

Regarding spectral sensitizers, 18716 (page 648 right column), 17643 (pages 23-24) and 18
716 (page 648, right column ~), supersensitizers are described in ``Yo'', and 18716 (page 649, right column ~), respectively. In addition, known additives that can be used in the present invention other than those mentioned above are also described in the two Research Disclosure journals mentioned above. For example, sensitivity enhancers are described in 18716 (page 648, right column), and antifoggants and stabilizers are described in 17643 (pages 24-25) and 18716 (page 649, right column ~). has been done. As the silver halide grains mentioned above, it is preferable to use silver halide grains having a relatively low fog value, such as the light-sensitive material described in JP-A-63-68830.

In the present invention, an organic metal salt can also be used as an oxidizing agent together with photosensitive silver halide. Among such organic metal salts, organic silver salts are particularly preferably used.

Organic compounds that can be used to form the above-mentioned organic silver salt include US Pat. No. 4,500,626,
There are benzotriazoles, fatty acids, and other compounds described in column 53, etc. Furthermore, silver salts of carboxylic acids having an alkynyl group such as silver phenylpropiolate described in JP-A-60-113235, and JP-A-61-249044
Also useful are acetylene silvers described in the publications of No. 64-57256. Two or more types of organic silver salts may be used in combination.

The above-mentioned organic silver salts contain, per mol of photosensitive silver halide,
0 to 10 mol, preferably 0 to 1 mol is used. The total coating amount of photosensitive silver halide and organic silver salt in the second layer is suitably 5 mg to 5 g/rn' in terms of silver.

The reducing agent contained in the second margin layer (23) has the function of reducing silver halide and/or the function of promoting (or suppressing) the polymerization of the binder polymer (unsaturated double bond groups therein). have

There are various types of reducing agents having the above functions. The reducing agents include hydroquinones, catechols, p-aminophenols, p-phenylenediamines, 3-pyrazolidones, 3-aminopyrazoles, 4
-amino-5-pyrazolones, 5-aminouracils,
4,5-tabidroxy-6-aminopyrimidines, reductones, amyl reductones, 0- or P-sulfonamidophenols, 0- or P-sulfonamidonaphthols, 2,4-disulfonamidophenols, 2. 4-disulfonamide naphthols, 0- or P-acylaminophenols, 2-sulfonamide indanones, 4-sulfonamide-5-pyrazolones,
Examples include 3-sulfonamide indoles, sulfonamide pyrazolobenzimidazoles, sulfonamide virazolotoinoazoles, α-sulfonamide ketones, and hydrazines. By adjusting the type, amount, etc. of the reducing agent, it is possible to polymerize the binder polymer in either the area where the silver halide latent image is formed or the area where no latent image is formed.

When hydrazine is used as a reducing agent alone or in combination with other reducing agents, polymerization generally occurs in the area where the silver halide latent image is formed. Further, when 1-phenyl-3-pyrazolidones, hydroquinones, or sulfonamidophenols are used as reducing agents without using hydrazines together, polymerization occurs in areas where a latent image of silver halide is not formed. However, in this case, it is necessary to add to the second layer (or first layer) a polymerization initiator that is decomposed by heating or light irradiation to uniformly generate radicals.

Thermal polymerization initiators are described, for example, in ``Addition Polymerization/Ring-Opening Polymerization'' (Kyoritsu Shuppan Co., Ltd., 1983), edited by the Japan Society of Polymer Science and the Editorial Committee for Polymer Experiments, pages 6 to 18. Specific examples of thermal polymerization initiators include azobisisobutyronitrile, 1,
1'-azobis(1-cyclohexanecarbonitrile)
, dimethyl 2.2°-azobisisobutyrate, 2,2
'Azo compounds such as azobis(2-methylbutyronitrile) and azobisdimethylvaleronitrile, benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, etc. organic peroxides, hydrogen peroxide,
Examples include inorganic peroxides such as potassium persulfate and ammonium persulfate, and sodium p-toluenesulfinate.

The photopolymerization initiator can be used, for example, as described by Oster et al. in Chem
-ical Review” No. 68 @ (1968)
pages 125-151 of
-5intensiveSysteJ (John Wj
158-1 of Lley & 5ons, 1965)
Carbonyl compounds (e.g., α-alkoxyphenyl ketones, polycyclic quinones, benzophenone derivatives, xanthones, thioxanthones, benzoins), halogen-containing compounds (e.g.,
chlorosulfonyl and chloromethyl polynuclear aromatic compounds,
chlorosulfonyl and chloromethyl heterocyclic compounds, chlorosulfonyl and chloromethylbenzophenones, fluorenones), haloalkanes, α-8-
α-phenylacetophenones, redox couples of photoreducible dyes and reducing agents, organic sulfur compounds, peroxides, photosemiconductors (e.g., titanium dioxide, zinc oxide), metal compounds (e.g., iron(I) salts, metal carbonyls, metal complexes, uranyl salts), silver halides, azo and diazo compounds, and the like.

Specific examples of photopolymerization initiators include 2-dimethoxy-2-
Phenylacetophenone, 2-methyl-(4-(methylthio)phenyl)-2-morpholino-1-propanone,
Hendiin butyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone, 4.4°
-diethylaminohensiphenone, chloromethylbenzophenone, chlorosulfonylbenzophenone, 9゜1
0-anthraquinone, 2-methyl-9,10-anthraquinone, chlorosulfonylanthraquinone, chloromethylanthraquinone, 9.10-phenanthrenequinone,
xanthone, chloroxanthone, thioxanthone, chlorothioxanthone, 2,4-diethylthioxanthone,
Examples include chlorosulfonylthioxanthone, chloromethylbenzothiazole, chlorosulfonylbenzoxazole, chloromethylquinoline, fluorene, carbon tetrabromide, and the like. Examples of photoreducible dyes include methylene blue thionine, rose bengal, and erythrosin-β.
, eosin, rhodamine, phloxin-β, safranin, acriflavin, riboflavin, fluorescein,
Examples include uranine, benzoflavin, acridine orange, acridine yellow, and penzanthrone.

Reducing agents (hydrogen donating compounds) used with these dyes include β-diketones such as dimedone and acetylacetone, triethanolamine, jetanolamine,
Amines such as monoethanolamine, diethylamine, and triethylamine.

Examples include sulfinic acids such as P-toluenesulfinic acid and pensenesulfinic acid and their salts, N-phenylglycine, L-ascorbic acid and its salts, thiourea, allylthiourea, and the like. The molar ratio of the photoreducible dye to the reducing agent is preferably in the range of 1:0.1 to 1:10.

As the photopolymerization initiator, commercially available ones, such as "Irgacure 651, Same 907" manufactured by Ciba Geigy, are also suitably used.

The polymerization initiator is o, oot per gram of binder polymer having an unsaturated double bond group in the side chain and an acidic group.
It is preferable to use it in the range of 0.5 g, more preferably in the range of 0.01 to 0.2 g.

This system is described in Japanese Patent Application Laid-Open No. 6175342.
No. 61-243449, No. 6270836, No. 62-81635, U.S. Patent No. 4649098
No. 0202490 and EP Patent No. 0202490.

Regarding various reducing agents having the above-mentioned functions, please refer to JP-A-61-
No. 183640, No. 61-188535, No. 61-2
No. 28441, JP-A-62-70836, JP-A No. 62-8
No. 6354, No. 62-86355, No. 62-2065
No. 40, No. 62-264041, No. 62-10943
No. 7, No. 63-254442 and patent application No. 1983
No. 3-97379, No. 63-296774, No. 63-
No. 296775, Japanese Patent Application No. 1-27175, No. 1-54
No. 101, No. 41-91162, etc. (including those described as developers or hydrazine derivatives). Regarding the above reducing agent, T, James
``The Theory of the Photo'' by s.
graphic Process'' 4th edition, 291-3
34 (1977), Research Disclosure, Vol. 170, No. 17029, pp. 9-15, (
June 1978) and the same magazine, Vol. 176, No. 1
There is also a description in No. 7643, pages 22-31 (December 1978). Furthermore, as in the photosensitive material described in JP-A No. 62-210446, a reducing agent @Komata which can release the reducing agent under heating conditions or in contact with a base may be used in place of the reducing agent. good. The reducing agents and reducing agent precursors described in each of the above-mentioned publications, specifications, and literatures can also be effectively used in the photosensitive material in this specification. Therefore,
In the present specification, the term "r-reducing agent" includes the reducing agents and reducing agent precursors described in each of the above-mentioned publications, specifications, and literatures.

Furthermore, among these reducing agents, those having basicity that form a salt with an acid can also be used in the form of a salt with an appropriate acid. These reducing agents may be used alone, but as described in each of the above specifications, two or more types of reducing agents may be used in combination. When using two or more types of reducing agents together, the interactions between the reducing agents include, firstly,
promoting the reduction of silver halide (and/or organic silver salts) by so-called hyper-oxidation, and secondly, oxidizing the first reducing agent produced by the reduction of silver halide (and/or organic silver salts). Possible methods include causing polymerization of the polymerizable compound (or suppressing polymerization) via an oxidation-reduction reaction with another reducing agent coexisting with the polymerizable compound. however,
In actual use, the reactions described above can occur simultaneously, so it is difficult to specify which effect is responsible.

The reducing agent is used in a range of 0.5 to 10 moles, more preferably in a range of 1 to 5 moles per mole of silver halide. Specific examples of the above reducing agent are shown below.

The following margins (1) (2) (7) (8) (12) The bases and base precursors contained in the second layer include inorganic bases and organic bases, or base breaker thereof (decarboxylated type, (thermal decomposition type, reaction type, complex salt forming type, etc.) can be used.

Examples of the inorganic base include those described in JP-A-62-209448. As an organic base, JP-A-62
Tertiary amine compounds described in JP-A-170954, bis-, tris-, or tetra-amidine compounds described in JP-A-63-316760, JP-A-64-687
Examples include the bis, tris, or tetraguanidine compounds described in Publication No. 46. In the present invention,
Bases with a pka of 7 or higher are preferred.

In the present invention, base precursors are preferred from the viewpoint of storage stability of the photosensitive material.

As a preferable base precursor, JP-A-63-31
No. 6760, No. 64-68746, No. 59-1805
No. 37, Salt of organic acid and base decarboxylated by heating described in Publication No. 61-313431, JP-A-63-96159
Examples include urea compounds that release a base upon heating as described in the above publication. In addition, as a method of releasing a base using a reaction, a reaction with a salt containing an anion having an affinity higher than that of an acetylide anion for transition metal acetylides and transition metal oins described in JP-A No. 63-25208; , Japanese Patent Application No. 63-187803 describes a basic metal compound that is sparingly soluble in water and a compound that can undergo a complex-forming reaction with water as a medium for the metal ions constituting this basic metal compound. The method of releasing the base by reaction between these two compounds is mentioned below.

The base precursor of the present invention is 50°C to 200°C.
It is preferable that the base be released at 80℃~
More preferably, the base is released at 160°C.

Incidentally, a photosensitive material using a base or a base precursor is described in JP-A-62-264041. Further, for a photosensitive material using a tertiary amine as a base, see JP-A-62-1170954, and for a photosensitive material using a fine particle dispersion of a hydrophobic organic base compound with a melting point of 80 to 180°C. Japanese Patent Publication No. 62-20952
3 describes a photosensitive material using a guanidine derivative with a solubility of 0.1% or less, and JP-A-63-70845 describes a photosensitive material using an alkali metal or alkaline earth metal hydroxide or salt. is JP-A-62-20
Publication No. 9448 has a description of each.

Furthermore, regarding a photosensitive material using an acetylide compound as a base precursor, JP-A-63-24242 discloses a photosensitive material using a propiolate as a base precursor.
Furthermore, regarding photosensitive materials containing silver, copper, silver compounds, or copper compounds as catalysts for base-forming reactions, JP-A-63-46
No. 446 discloses the above propiolic acid salt and the above silver, copper,
Regarding a photosensitive material containing a silver compound or a copper compound in a state separated from each other, JP-A-63-81338 discloses that in addition to the above-mentioned propiolic acid salt and the above-mentioned silver, copper, silver compound, or copper compound, coordination in a free state JP-A-63-97942 describes a photosensitive material containing a base precursor, and JP-A-63-9794 describes a photosensitive material that uses a propiol salt as a base precursor and further contains a heat-melting compound as a reaction accelerator for the base production reaction. No. 46447 describes a photosensitive material that uses a sulfonylacetate as a base precursor and further contains a heat-melting compound as a reaction accelerator for the base production reaction, and JP-A No. 63-48453 describes a method for using an organic base as a base precursor. For photosensitive materials using isocyanates or compounds bonded with isothiocyanates, see JP-A No. 63-96652, and for photosensitive materials containing nucleophiles as decomposition accelerators for these compounds, see JP-A No. 63-173039. There are descriptions in each issue.

For photosensitive materials using bis- or trisamidine salts of carboxylic acids that can be carbonated as base precursors, see JP-A-64-9441, and for photosensitive materials using bis- or tris-guanidine salts, see JP-A-64-9441.
There are descriptions in JP-A-68749. The base or base precursor is 0.5 per mole of halogenated
It is preferably used in a range of 50 moles, more preferably 1 to 20 moles.

A hot solvent can be introduced into the second layer.

The thermal solvent has the function of accelerating thermal decomposition of the base precursor when heated, or accelerating the development of silver halide by dissolving the base or reducing agent.

Examples of the heat solvent include polyethylene glycols described in U.S. Pat. No. 3,347,675, derivatives such as oleic acid esters of polyethylene oxide, beeswax, monostearin, and high dielectric constant materials having -5O2- and/or 100- groups. Compounds such as polar compounds described in US Pat. No. 3,667,959, 1,10-decanediol, methyl anisate, and biphenyl perate described in Research Disclosure Magazine, December 1976 issue, items 26-26 can be preferably used. Also, urea, dimethylurea,
Ureas such as methylurea and ethylurea can also be preferably used. Among these, ureas are particularly preferred.

A water-soluble binder polymer (without acid groups) can be introduced into the second layer. The water-soluble binder polymer preferably binds the components in the second layer and also has the function of preventing oxygen in the air from diffusing into the first layer and inhibiting the polymerization reaction. . for example,
Polyvinyl alcohol, polyvinylpyrrolidone, gelatin, poly(meth)acrylate, poly(meth)acrylamide, polystyrene sulfinate, methylcellulose, gum arabic, and the like are used. Molecular weight is approximately 1-5
A range of 0,000 is preferable. Among these, polyvinyl alcohol has an excellent oxygen blocking function and is particularly preferred.

In the photosensitive material (30) having the structure shown in FIG. 3, the water-soluble binder polymer having no acidic group is contained in the second layer (34) as an essential component. In this case, the coating amount of the water-soluble binder polymer is 0.1
It is preferable to use the coating amount in the range of ~10g/m'', more preferably 0.3~3g/rn''
is within the range of

The second layer can contain various antifoggants or stabilizers. Examples include Research Disclosure, No. 17643, pp. 24-25 (1
azoles and azaindenes described in JP-A-59-168442), nitrogen-containing carboxylic acids and phosphoric acids described in JP-A-59-168442, or JP-A-59-11163;
Mercapto compounds and metal salts thereof described in Japanese Patent Publication No. 62-87957, acetylene compounds described in Japanese Patent Application Laid-Open No. 62-87957, and the like can be used. Although the antifoggant can be incorporated into the first layer, it is preferably incorporated into the second layer. The amount used is 1 per mole of silver halide.
It ranges from 0-4 mol to 1 mol.

For photosensitive materials, there are various processing temperatures and processing times during development.
Various development stoppers can be used for the purpose of always obtaining a constant image. The development stopper referred to here is a compound that neutralizes the base immediately after proper development or reacts with the base to lower the base concentration in the layer and stop development, or a compound that inhibits development by interacting with silver and silver salts. It is a compound that causes Specific examples include acid precursors that release acids when heated, electrophilic compounds that cause a substitution reaction with a coexisting base when heated, nitrogen-containing heterocyclic compounds, mercapto compounds, and their precursors. For more details, see JP-A-62-
No. 253159 (pages 31-32), patent application No. 1-7247
No. 9 and No. 1-3471. These may be contained in either the first layer or the second layer.

The second layer (24) is prepared by dispersing or dissolving photosensitive silver halide, a reducing agent, and a base or base precursor (and optional components) in water to prepare a coating solution, and then applying this to the second layer (24). It can be provided by coating on one layer and drying it. Note that two or three of the above components are dissolved using a suitable solvent and added to the stored water in the form of a solution.

The thickness of the second layer is preferably in the range of 0.5 to 20 μm, more preferably in the range of 1 to 5 μm. The coating amount of photosensitive silver halide is 0.5 in terms of metallic silver.
It is preferably in the range of mg/rn' to 5 g/rn', more preferably 3 mg/rIT' to 0.5 g/rn'.
The range is rr1'.

Note that the second layer (34) can also be formed in the photosensitive material having the structure shown in FIG. 3 by the same method as described above. In this case, the layer thickness of the second layer (34) or the coating amount of photosensitive silver halide is within the same range as above.

If desired, a layer of the above water-soluble binder bomber (for example, polyvinyl alcohol) can be further provided on the second layer as a protective layer or an oxygen barrier layer. The layer thickness is preferably in the range of approximately 0 to 10 μm.

Next, an image forming method (method for manufacturing a lithographic printing plate) using the photosensitive material of the present invention will be described.

The method for manufacturing a lithographic printing plate consists of the following steps.

That is, the process of imagewise exposing the photosensitive material, the process of thermal development treatment at the same time as the imagewise exposure or after the imagewise exposure, and the process of ethylenically unsaturated double bonds in the side chains of silver halide where no latent image is formed. When polymerizing a polymer binder having
It consists of a process of etching. Note that in the case of a photosensitive material having a structure in which the first layer contains an acidic group (FIG. 3), the above-mentioned etching is performed using an alkaline aqueous solution.

Exposure is performed using a light source that emits light of a wavelength corresponding to the spectral sensitivity (sensitizing dye) of the silver halide. Examples of such light sources include lamps such as tungsten lamps, halogen lamps, xenon lamps, mercury lamps, and carbon arc lamps, various lasers (semiconductor lasers, helium neon lasers, argon lasers, helium cadmium lasers, etc.), and light emitting diodes. , CRT tube, etc. are used. The exposure wavelength is generally preferably visible light or near ultraviolet light. The exposure amount is mainly determined by the sensitivity of the silver halide emulsion, but is generally 0.01 to 10,000 ergs/c.
The range of m2 is preferable, more preferably 0.1 to 100
It is in the range of 0 ergs/cm2.

By imagewise exposing the photosensitive material using the above light source, a latent image of silver halide is formed in the exposed area.

The thermal development treatment is carried out simultaneously with or after the imagewise exposure described above.

Heating can be by contact with a heated object (e.g. a plate roller) or by radiant heat from an infrared-rich lamp.
This can be done by immersing it in a medium such as heated oil. In order to reduce inhibition of the polymerization reaction by oxygen in the air that enters during heating, heating is preferably performed with the surface of the photosensitive material covered with a substance that is difficult for oxygen to pass through. For example, a method in which the photosensitive surface is brought into close contact with a heated object and heated is preferred. The heating temperature is preferably in the range of 80 to 200°C, more preferably 100 to 150°C.
℃ range. The heating time ranges from 1 to 180 seconds,
More preferably, it is in the range of 5 to 60 seconds. The binder polymer in the area where the silver halide latent image is formed (or the area where the latent image is not formed) is polymerized and hardened by the above heat development process, and an image-like polymer image is formed in the first layer. Ru. Further, there is no need to separately perform heating to polymerize the polymerizable compound in the area where the silver halide latent image is not formed (heating only during thermal development is sufficient). For light irradiation, the same method as the imagewise exposure described above (however,
Imagewise exposure can be carried out by using different wavelengths and amounts of light.

Next, the uncured areas (non-image areas) are washed with an organic solvent and removed (etched).

By the above operation, the uncured portions of the second layer and the first layer are eluted and removed, and a relief image consisting of the cured portion of the first layer is formed on the support.

Note that the image thus obtained can also be used for purposes other than printing plates, such as reliefs, hard copies, and the like.

The present invention will be explained in more detail with reference to the following examples. However, the present invention is not limited to these.

[Example 1] [Preparation of photosensitive material] Aluminum, -' The surface of an aluminum plate with a thickness of 0.30 mm was grained using a nylon brush and a water suspension of 400 mesh of pumice stone, and then the surface was grained with water. Washed thoroughly. Then,
After etching by immersing it in 10% sodium hydroxide at 70°C for 60 seconds, it was washed with running water, neutralized with a 20% aqueous nitric acid solution, and washed with water. The anode voltage is 12.7V-
r - Electrolytic roughening with an anode specific electricity amount of 160 coulombs/drn'' in a 1% nitric acid aqueous solution using a sinusoidal alternating waveform current under the condition that the ratio of the cathode specific electricity amount to the anode specific electricity amount is 0.8. Surface roughening treatment was carried out.The surface roughness at this time was measured and found to be 0.6μ (indicated by Ra).

Subsequently, it was immersed in a 30% sulfuric acid aqueous solution and desmutted at 55°C for 2 minutes, and then anodized in a 20% sulfuric acid aqueous solution at a current density of 2 A/dm' to a thickness of 2.7 g/drn''. Did.

Second go λ layer! 0.17 g of ethyl cellulose (trade name: N-200, manufactured by Vercules) was dissolved in 48 g of methyl ethyl ketone. Pigment (trade name: Microlith Red 1) is added to this solution.
77A, manufactured by Ciba Geigy) was added thereto, and treated with an ultrasonic disperser for 30 minutes to finely disperse the pigment. Next, 5.5 g of a 20% by weight solution of allyl methacrylate/methacrylic acid copolymer (copolymerization ratio = 83717) in methyl ethyl ketone was mixed with the obtained dispersion, and 0.3 g of dibutyl phthalate was further added to prepare a coating liquid. . Coating this coating solution onto the aluminum support and drying it,
A first layer was provided. The layer thickness of the first layer was 1.0 μm.

A gelatin aqueous solution (16 g of seratin and 0.5 g of sodium chloride were added to 1500 mβ of water, adjusted to pH 3.2 with IN sulfuric acid, and kept at 50°C) was mixed with an aqueous solution of 300 + nJZ containing 71 g of potassium bromide while stirring. An aqueous silver nitrate solution (0.59 mol of silver nitrate dissolved in 300 ml of water) was simultaneously added at an equal flow rate over 50 minutes. One minute after this was completed, 200 rnJZ of an aqueous solution containing 4.3 g of potassium iodide was added at a constant flow rate over 5 minutes. 1.2 g of poly(imbutylene-monosodium co-maleate) was added to this emulsion and precipitated.
After washing with water and desalting, add 24g of gelatin and dissolve.
Furthermore, 5 mg of sodium thiosulfate and 0.5 g of the following sensitizing dye were added to carry out chemical sensitization at 60° C. for 15 minutes to prepare a silver halide emulsion with a yield of 1000 g.

Margin below (sensitizing dye) 1.3 g of the following reducing agent (a), 2.
4g of the following compound (c) 0-0048mg and the following compound (d) 0.027mg were dissolved in a mixed solvent of 3.5g of propylene glycol monomethyl ether and 8g of methylene chloride, and the resulting mixed solution was dissolved in polyvinyl alcohol. The mixture was emulsified in 60 g of a 10% aqueous solution using a homogenizer.

(Reducing agent (a)) (Reducing agent (b)) (Compound (C)) 250 g of the following base precursor powder was dispersed in 750 g of a 3% by weight aqueous solution of polyvinyl alcohol using a Dyno Mill disperser. The particle size of the base precursor was about 0.5 μm or less.

In 40 g of water, 13.2 g of the emulsion containing the above reducing agent, 3.7 g of base precursor dispersion, and 4 g of urea (thermal solvent).
Add 1.1 g of a 0% aqueous solution and 3.7 g of a 5% aqueous solution of the following surfactant, and further add the above silver halide emulsion 10.
2.7 g of a mixture of 10 g and 20 g of a 10% aqueous solution of polyvinyl alcohol were added and mixed well to prepare a coating solution for the second layer. This was applied onto the first layer and dried to form a second layer, thereby producing a photosensitive material according to the present invention (corresponding to the structure shown in FIG. 3). The layer thickness of the second layer was 3.0 μm.

[Image forming method and evaluation thereof] A printing plate was prepared from the photosensitive material (printing original plate) obtained above as follows and evaluated.

The original film was brought into close contact with the photosensitive material and exposed for one second at an illuminance of 50 lux using a 500 W tungsten lamp. Next, when this was heat-developed by placing it on a hot plate heated to 135° C. for 30 seconds, a silver image was observed in the exposed areas. Next, this was immersed in a 10% by weight aqueous solution of triethanolamine at room temperature for 1 minute, and then thoroughly washed with water. The second layer and the first layer in the exposed area were eluted and removed, leaving a red color in the exposed area. A colored polymer relief image was formed.

When the printing plate thus obtained was attached to a Heidel OR-D printing machine and printed, good printed matter was obtained.

[Example 2] [Preparation of photosensitive material] In the formation of the first layer of Example 1, allyl methacrylate/hydroxyethyl methacrylate copolymer (
A photosensitive material according to the present invention (corresponding to the structure shown in FIG. 2) was prepared in the same manner as in Example 1, except that the same amount of copolymerization ratio=85/15) was used.

[Image forming method and evaluation thereof] After exposure and thermal development in the same manner as in the image forming method of Example 1, the second layer was removed by washing with water. Next, this was immersed in methanol for 1 minute at room temperature. The exposed portion of the second layer was eluted and removed with methanol, and a red-colored polymer relief image (positive image) was formed in the exposed portion.

When the printing plate thus obtained was attached to a Heidel KOR-D printing machine and printed, good printed matter was obtained.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are each a schematic cross-sectional view of a photosensitive material according to the present invention. 11.21.31: Support 12: Photosensitive layer 23.33: First layer 24.34: Second layer

Claims (1)

[Scope of Claims] 1. A support containing a photosensitive silver halide, a reducing agent, a binder polymer having an ethylenically unsaturated double bond in a side chain, and a base or a base precursor, which is substantially polymerizable. A photosensitive material that has a photosensitive layer that does not contain a compound. 2. The photosensitive layer has a multilayer structure of a first layer and a second layer, and the binder polymer having an ethylenically unsaturated double bond in the side chain is in the lower first layer. The photosensitive material according to claim 1, characterized in that it contains: 3. On the support, a mixture of a binder polymer having an ethylenically unsaturated double bond in the side chain and a binder polymer having an acidic group, or a binder polymer having an ethylenically unsaturated double bond in the side chain and an acidic group. and a second layer thereon comprising a water-soluble binder polymer having no base or base precursor and acidic groups, wherein the photosensitive silver halide and the reducing agent are A photosensitive material contained in one of the layers. 4. The photosensitive material according to claim 3, wherein the photosensitive silver halide is contained in the second layer. 5. The photosensitive material according to claim 3 or 4, wherein the first layer further contains a colored pigment and ethyl cellulose.