JP2001033972A - Photosensitive material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a photosensitive material in which silver halide grains are hardly aggregated even when it is produced by simultaneous coating. SOLUTION: A hardenable layer 2 containing a polymerizable compound or a crosslinkable polymer, a photosensitive layer 3 containing gelatin stuck silver halide grains dispersed in a hydrophilic synthetic polymer and an image formation promoting layer 4 containing a base precursor and a hydrophilic polymer are successively laminated on an aluminum substrate 1 to obtain the objective pbotosensitive material. The hardenable layer 2 or the photosensitive layer 3 contains a reducing agent. The electric conductivity of a solution prepared by dissolving the photosensitive layer 3 in water at 40 deg.C in 10 wt.% solid content is <800 μS/cm. Paper, synthetic paper or paper with a laminated synthetic resin (e.g. polyethylene or polypropylene) may be used in place of the aluminum substrate. When the photosensitive material is used in the production of a planographic printing plate, an aluminum sheet or a polyethylene terephthalate film is preferably used as the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive material in which a curable layer, a photosensitive layer, and an image formation accelerating layer are provided in this order on a support, and a method for producing the same.

[0002]

2. Description of the Related Art A method for forming a polymer image by imagewise exposing a photosensitive material containing a silver halide, a reducing agent and a polymerizable compound to develop the silver halide and thereby polymerizing the polymerizable compound in an image-like manner. Are disclosed in Japanese Patent Publication Nos. 3-12307 and 3-12308 (US Pat. No. 4,296,296).
No. 76 and European Patent 0174634). In this method, polymerization is initiated by an oxidant radical of a reducing agent that has reduced silver halide (which may be a radical generated by decomposition of an oxidant of the reducing agent; hereinafter, simply referred to as an oxidant radical). . Specifically, the photosensitive material is heated to develop the silver halide, and heat development for forming a cured image of the polymerizable compound is performed.

[0003] The image forming method described above can also be applied to the production of a printing plate. A photosensitive material suitable for producing a printing plate is disclosed in JP-A-5-249667 (US Pat.
No. 22443 and European Patent No. 0426192) and JP-A-4-191856 (U.S. Pat.
No. 29,659). In a photosensitive material used for producing a printing plate, generally, a curable layer containing a polymerizable compound or a crosslinkable polymer, a photosensitive layer containing silver halide, and an image formation accelerating layer containing a base precursor are provided on a support. The reducing agent is added to the curable layer or the photosensitive layer. In a method for producing a printing plate using silver halide, a polymerizable compound or a crosslinkable polymer is cured by thermal development, and then the photosensitive layer and the image formation accelerating layer are removed from the photosensitive material. The uncured portion is removed, and the remaining cured (replica) image is used as a printing plate image.

[0004] The photosensitive layer is formed by dispersing silver halide particles in a hydrophilic polymer. The silver halide grains are prepared as a silver halide emulsion using gelatin as a protective colloid. Therefore, a photosensitive layer containing gelatin as a hydrophilic polymer can be formed only by coating a silver halide emulsion. However, when gelatin is used as the hydrophilic polymer, the diffusion of components in the photosensitive layer during thermal development is insufficient, and a good image cannot be formed. Therefore, a hydrophilic synthetic polymer is generally used for the photosensitive layer instead of gelatin. However, it is difficult to completely remove the gelatin used for preparing the silver halide grains from the silver halide grains. Therefore, the photosensitive layer is in a state in which the silver halide grains to which gelatin has adhered are dispersed in the hydrophilic synthetic polymer.

[0005]

The curable layer and the photosensitive layer are separated from each other, and the photosensitive layer is formed as a layer in which silver halide grains to which gelatin is adhered are dispersed in a hydrophilic synthetic polymer. Thereby, an image usable as a printing plate can be formed. The present inventor has conducted a study for putting the photosensitive material into practical use. As a result, a problem was observed that silver halide grains were not aggregated at the experimental stage. In a practical stage, a photosensitive layer and an image formation accelerating layer are formed by simultaneous application in order to produce a photosensitive material in a short time. At the experimental stage, these layers were applied sequentially. In the simultaneous coating, it is necessary to change the composition of the coating liquid as compared with the case of sequential coating in order to prevent mixing of components between layers. According to the study of the present inventors, it has been found that silver halide grains are likely to aggregate when a composition (particularly viscosity adjustment) of a coating solution suitable for simultaneous coating is employed. The object of the present invention is, even if manufactured by simultaneous coating,
An object of the present invention is to provide a light-sensitive material in which aggregation of silver halide grains hardly occurs.

[0006]

The above objects have been achieved by the following (1) to (3) photosensitive materials and the following (5) to (6) photosensitive material manufacturing methods. (1) A curable layer containing a polymerizable compound or a crosslinkable polymer on a support, a photosensitive layer in which silver halide particles to which gelatin is adhered are dispersed in a hydrophilic synthetic polymer, and a base precursor and hydrophilicity An image formation accelerating layer containing a polymer is laminated in this order, and the curable layer or the photosensitive layer is a photosensitive material containing a reducing agent, and the photosensitive layer is dissolved in water at 40 ° C. at a solid content of 10% by weight. A light-sensitive material, wherein the conductivity of the solution is less than 800 μS / cm. (2) The photosensitive material according to (1), wherein the amount of gelatin in the photosensitive layer is 0.01 to 10% by weight of the amount of the hydrophilic synthetic polymer. (3) When the hydrophilic synthetic polymer in the photosensitive layer is 70 to 9
The photosensitive material according to (1), which is a polyvinyl alcohol having a saponification degree of 9.9%.

(4) A step of providing a curable layer containing a polymerizable compound or a crosslinkable polymer on a support, and, on the curable layer, silver halide grains having gelatin adhered thereto are mixed with a hydrophilic synthetic polymer. A step of simultaneously applying a coating solution of a photosensitive layer dispersed in a photosensitive layer and a coating solution of an image formation promoting layer containing a base precursor and a hydrophilic polymer, wherein the conductivity of the coating solution of the photosensitive layer is less than 800 μS / cm. Material manufacturing method. (5) The conductivity of the photosensitive layer coating solution is adjusted by adding potassium bromide to the photosensitive layer coating solution (4).
The production method described in 1.

[0008]

As a result of the study of the present invention, when the conductivity of the photosensitive layer coating solution is adjusted to less than 800 μS / cm, the aggregation of silver halide particles in the photosensitive layer coating solution during simultaneous coating is prevented. It turns out that it can. The conductivity of the photosensitive layer coating solution can be estimated from the conductivity of a solution obtained by dissolving the photosensitive layer in water at 40 ° C. at a solid content of 10% by weight. The photosensitive layer coating solution in the sequential coating has an electric conductivity of 800 μS / cm.
With the above, the coating liquid is stable. Therefore, in the conventional (experimental) photosensitive layer, the conductivity is 800 μS / c.
m or more. However, with the transition from the experimental stage to the practical stage, by sequentially changing the coating to the simultaneous coating, the preferable conductivity of the photosensitive layer coating solution was completely different. For the above reasons, the photosensitive material of the present invention is
Aggregation of silver halide grains is unlikely to occur even when they are produced by coating in a practical stage.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION [Electrical Conductivity]
The conductivity of a solution in which the photosensitive layer is dissolved in water at 40 ° C. at a solid content of 10% by weight is adjusted to less than 800 μS / cm. For that purpose, it is preferable to adjust the conductivity of the photosensitive layer coating solution to less than 800 μS / cm. Conductivity is 100 to 7
It is preferably 80 μS / cm, and 200 to 76
It is more preferably 0 μS / cm, most preferably 300 to 740 μS / cm. The conductivity is preferably adjusted by adding potassium bromide to the coating solution for the photosensitive layer. In the prior art, potassium bromide is added to a coating solution for a photosensitive layer as a silver potential regulator (described in JP-A-5-142775). In the present invention, the addition amount of potassium bromide can be adjusted so as to obtain a preferable electric conductivity. When simultaneous coating is employed as a method for producing a light-sensitive material, the amount of potassium bromide is preferably determined by giving priority to the above-described conductivity over the silver potential described in JP-A-5-142775.

[Layer Structure of Photosensitive Material] A photosensitive material is provided on a support in the order of a curable layer, a photosensitive layer and an image formation promoting layer. The reducing agent is added to the curable layer or the photosensitive layer. It is preferable that the components of each layer are uniformly contained in the layer without using microcapsules. The photosensitive material may be provided with a functional layer other than the above. Other functional layers include:
It includes an adhesive layer, an adhesive layer, a release layer, an undercoat layer, an intermediate layer and an overcoat layer. Hereinafter, a typical layer configuration will be described with reference to the drawings.

FIG. 1 is a schematic sectional view showing a typical layer structure of the light-sensitive material of the present invention. In the photosensitive material shown in FIG. 1, a curable layer (2), an aluminum support (1),
A photosensitive layer (3), an image formation accelerating layer (4) and an overcoat layer are sequentially provided. The curable layer (2) contains a polymerizable compound (21) and a crosslinkable polymer (22). The photosensitive layer (3) contains silver halide grains (31) to which gelatin (32) is adhered, a reducing agent (33), a hydrophilic synthetic polymer (34), and potassium bromide (35). The image formation promoting layer (4) is composed of a base precursor (4
1) and a hydrophilic polymer (42). The overcoat layer (5) contains a hydrophilic polymer (51). The conductivity of the photosensitive layer (3) is adjusted by potassium bromide (35).

[Support] As the support, paper, synthetic paper,
Paper laminated with synthetic resin (eg, polyethylene, polypropylene, polystyrene), plastic film (eg, polyethylene terephthalate, polycarbonate, polyimide, nylon, cellulose triacetate), metal plate (eg, aluminum, aluminum alloy,
Zinc, iron, copper), and paper or plastic film on which these metals are laminated or deposited can be used. When the photosensitive material is used for producing a lithographic printing plate, preferred supports are an aluminum plate, a polyethylene terephthalate film, a polycarbonate film, paper and synthetic paper. Further, a composite sheet in which an aluminum sheet is laminated on a polyethylene terephthalate film is also preferable. Aluminum plates are particularly preferred.

The case where an aluminum plate is used as a support will be further described. The aluminum support is subjected to a surface treatment such as a surface roughening treatment (graining treatment) or a surface hydrophilic treatment as necessary. The surface roughening treatment may be performed by an electrochemical sanding method (for example, a method of sanding an aluminum plate by passing an electric current in a hydrochloric acid or nitric acid electrolyte) and / or a mechanical sanding method. (For example, a wire brush grain method in which the aluminum surface is scratched with a metal wire, a ball grain method in which the aluminum surface is sanded with a polishing ball and an abrasive, a brush grain in which the surface is sanded with a nylon brush and an abrasive) Method). Next, the grained aluminum plate is chemically etched with acid or alkali. An industrially advantageous method is etching using an 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 the alkaline solution is preferably in the range of 1 to 50% by weight. The temperature of the alkali treatment is preferably in the range of 20 to 100 ° C. Further, it is preferable to adjust the processing conditions so that the amount of aluminum dissolved is 5 to 20 g / m ² .

Usually, after the alkali etching, the aluminum plate is washed with an acid to remove dirt (smut) remaining on the surface. Preferred acids are nitric acid, sulfuric acid,
Phosphoric acid, chromic acid, hydrofluoric acid and borofluoric acid. The smut removal treatment after the electrochemical graining treatment can be performed by a known method such as a method of contacting with sulfuric acid at a concentration of 15 to 65% by weight at 50 to 90 ° C. The aluminum plate subjected to the surface roughening treatment as described above can be subjected to an anodic oxidation treatment or a chemical conversion treatment, if necessary. The anodic oxidation treatment can be performed by a known method. Specifically, an anodic oxide film is formed on the aluminum surface by passing a direct current or an alternating current through an aluminum plate in an acid solution. Examples of acids include sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid and benzenesulfonic acid. Anodizing conditions vary depending on the electrolyte used. Generally, 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 0.5%.
To 60 amps / dm ^2, a voltage of ^from 1 to 100v, and electrolysis time is preferably in the range of 10 to 100 seconds. Particularly preferred anodic oxidation methods are a method of performing anodization at a high current density in sulfuric acid and a method of performing anodization using phosphoric acid as an electrolytic bath. After the anodizing treatment, the aluminum plate may be subjected to an alkali metal silicate treatment (for example, a treatment of immersing the aluminum plate in an aqueous solution of sodium silicate). In order to improve the adhesion between the aluminum support and the curable layer and the printing characteristics, an undercoat layer may be provided on the support surface.

[Undercoat layer] The undercoat layer is provided as a hydrophilic layer not only on the above-mentioned aluminum support but also on a support whose surface is not sufficiently hydrophilic (eg, a polymer film). As a component constituting the undercoat layer, a polymer (eg,
Gelatin, casein, polyvinyl alcohol, ethyl cellulose, phenolic resin, styrene-maleic anhydride resin, polyacrylic acid); amines (eg, monoethanolamine, diethanolamine, triethanolamine,
Tripropanolamine) and their hydrochlorides, oxalates or phosphates; monoaminomonocarboxylic acids (eg, aminoacetic acid, alanine); oxyamino acids (eg,
Serine, threonine, dihydroxyethylglycine);
Sulfur-containing amino acids (eg, cysteine, cystine); monoaminodicarboxylic acids (eg, aspartic acid, glutamic acid); diaminomonocarboxylic acids (eg, lysine); amino acids having an aromatic nucleus (eg, p-hydroxyphenylglycine, phenylalanine) Aliphatic aminosulfonic acid (eg, sulfamic acid, cyclohexylsulfamic acid); and (poly) aminopolyacetic acid (eg, ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, hydroxyethylethylenediamine) Acetic acid, ethylenediaminediacetic acid, cycloethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, glycol etherdiaminetetraacetic acid). A compound in which some or all of the acid groups of the above compounds have become salts (eg, sodium salt, potassium salt, ammonium salt) can also be used. The above components can be used in combination of two or more. When a polymer film is used as the support, hydrophilic fine particles (eg, silica powder) are preferably added to the hydrophilic undercoat layer instead of the graining treatment of the aluminum support.

[Curable Layer] The curable layer is a layer containing a polymerizable compound or a crosslinkable polymer. The curable layer preferably contains a polymerizable compound and a crosslinkable polymer. The amount of the polymerizable compound is 3 to 200 times the amount of the crosslinkable polymer.
%, More preferably from 10 to 100% by weight. The amount of the crosslinkable polymer is preferably from 30 to 95% by weight, more preferably from 50 to 90% by weight of the whole curable layer. The thickness of the curable layer is preferably from 0.1 to 20 μm, more preferably from 0.3 to 7 μm.

[Adhesive Layer] An adhesive layer may be provided to enhance the adhesive force between the curable layer (hydrophobic) and the photosensitive layer (hydrophilic). As long as the adhesive function of the adhesive layer is maintained, a layer other than the adhesive layer (for example, a hydrophilic layer containing no silver halide) is interposed between the curable layer and the photosensitive layer. Is also good. The adhesive layer preferably contains a hydrophilic polymer described below as a binder. The coating amount of the adhesive layer is preferably 0.01 to 2.5 g / m ² , more preferably 0.02 to 2.0 g / m ² , and more preferably 0.05 to 1.5 g / m 2. Most preferably, it is ² .

[Photosensitive Layer] The photosensitive layer is a layer containing silver halide grains to which gelatin is adhered and a hydrophilic synthetic polymer. In order to adjust the electric conductivity as described above, the photosensitive layer preferably further contains potassium bromide. The coating amount of silver halide is 0.01 to 5 g / m ^{2 in} terms of silver.
Is preferably 0.03 to 1 g / m ² , more preferably 0.05 to 0.3 g / m ² . The thickness of the photosensitive layer is 0.07
To 13 μm, preferably 0.2 to 5 μm
Is more preferable.

[Image formation promoting layer] The image formation promoting layer contains a base precursor. The image formation promoting layer preferably contains a hydrophilic polymer in addition to the base precursor. The thickness of the image formation promoting layer is preferably from 0.3 to 20 μm, more preferably from 0.5 to 7 μm.

[Intermediate layer] An intermediate layer can be provided on the light-sensitive material. The intermediate layer can also function as an antihalation layer, a filter layer, or a barrier layer. The antihalation layer and the filter layer are functional layers containing a coloring agent. The barrier layer has a function of preventing components from migrating between layers and diffusing or mixing during storage of the photosensitive material. The material of the intermediate layer is determined according to the application. The thickness of the intermediate layer is preferably 10 μm or less.

[Overcoat layer] The overcoat layer contains a hydrophilic polymer. The thickness of the overcoat layer is preferably 0.3 to 20 μm,
More preferably, the thickness is from 7 to 7 μm.

[Silver halide grains] Silver halide grains include silver chloride, silver bromide, silver iodide, and silver chlorobromide, silver chloroiodide, silver iodobromide, and silver chloroiodobromide. Can also be used. The shape of the silver halide grains is preferably cubic or tetradecahedral, but is not limited to those having a regular crystal form, and may be those having an irregular crystal form or a complex form thereof. Anomalous crystal forms include potato, spherical, plate and plate crystal forms. In the case of tabular grains, the grain size is generally at least five times the grain thickness.

There is no particular limitation on the size of the silver halide grains. Fine particles of 0.01 μm or less can also be used. On the other hand, large particles of about 10 μm can be used. With respect to grain size distribution, monodisperse grains are preferred over polydisperse emulsions. For monodisperse emulsions, see US Pat.
Nos. 628 and 3655394 and British Patent 1413.
No. 748 is described in each specification. The crystal structure of the silver halide grains may be uniform or may have a different halogen composition between the inside and the outside. It may have a layered structure. Further, silver halides having different compositions may be joined by epitaxial joining. Further, it may be bonded to a compound other than silver halide. Examples of compounds other than silver halide include silver rhodan and lead oxide.

The silver halide grains may contain salts of other elements. Examples of other elements include copper, thallium, lead, bismuth, cadmium, zinc, chalcogens (eg, sulfur, selenium, tellurium), gold and VI.
Group II noble metals (eg, rhodium, iridium, iron, platinum, palladium) can be mentioned. Salts of these elements can be added during or after the formation of silver halide grains and included in the grains. Specific methods are described in U.S. Patent Nos. 1195432 and 1951933,
No. 2448060, No. 2628167, No. 2950
No. 972, No. 3488709, No. 3737313,
Nos. 3772031 and 4269927, and Research Disclosure (RD), No. 13,
No. 4, No. 13452 (June 1975). By adding an aqueous solution of an iridium compound to the emulsion during the preparation of the silver halide emulsion, iridium ions can be introduced into the silver halide grains. Examples of water-soluble iridium compounds include hexachloroiridium (II
I) acid salts and hexachloroiridium (IV) salts. Similarly, rhodium ions may be introduced into silver halide grains by adding an aqueous solution of a rhodium compound to the emulsion. Examples of the water-soluble rhodium compound include rhodium ammonium chloride, rhodium trichloride and rhodium chloride.

An iridium compound or a rhodium compound may be used by dissolving it in an aqueous halide solution for forming silver halide grains. Further, the aqueous solution of the iridium compound or the rhodium compound may be added before the particles are formed, or may be added during the formation of the particles. Further, it may be added during the period from grain formation to chemical sensitization treatment. It is particularly preferred to add while the particles are being formed. The iridium ion or the rhodium ion is preferably used in an amount of 10 ^{-8 to} 10 ^-3 mol, more preferably 10 ^{-7 to} 10 ^-5 mol, per 1 mol of silver halide. Two or more silver halide grains having different halogen compositions, crystal habits and grain sizes can be used in combination. Silver halide is preferably used as an emulsion. Silver halide emulsions are described in Research Disclosure (RD) Magazine, No. 17643 (December 1978), pp. 22-23, "I. Emulsion Production (Emulsion p.
reparation and types) "and No. 18716
(November 1979), page 648.

The silver halide emulsion is usually subjected to chemical sensitization after physical ripening. It is preferable to use silver halide grains having a relatively low fog value. Additives used in such a process are described in Research Disclosure Magazine, No. 1
No. 7643 and the same No. 18716. Regarding chemical sensitizers, 17643 (p. 23) and
No. 18716 (page 648, right column). Known additives other than those described above are also described in the above two Research Disclosures. For example, as for the sensitivity enhancer, 18716 (648
In the right column of the page), for the antifoggant and the stabilizer, N
o. No. 17643 (pages 24 to 25) and no. 18716
(From page 649, right column). As previously mentioned,

The silver halide emulsion is usually used after spectral sensitization. As the sensitizing dye used in the light-sensitive material, a silver halide sensitizing dye known in the photographic art can be used. Examples of sensitizing dyes include cyanine dyes,
Examples include merocyanine dyes, complex merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Spectral sensitizing dyes are used to adjust the spectral sensitivity of photosensitive materials to different light source wavelengths such as various lasers (eg, semiconductor laser, helium neon laser, argon ion laser, helium cadmium laser, YAG laser) and light emitting diodes. Can also be used. For example, applying a plurality of spectral sensitizing dyes having different spectral wavelengths to silver halide in the same or different photosensitive layers to enable writing on the same photosensitive material using light sources having different wavelengths. Can also. In addition to the sensitizing dye, a dye which does not itself have a spectral sensitizing effect or a compound which does not substantially absorb visible light and exhibits supersensitization (supersensitizer) can be added to the emulsion. Good. Spectral sensitizing dyes are described in Research Disclosure Magazine, No. 17643 (197
December, 8), pp. 23-24, for supersensitizers
No. 18716 (November 1979), p. 649,
Each is listed.

[Organic metal salt] In addition to the silver halide, an organic metal salt can be added to the light-sensitive material. It is particularly preferable to use an organic silver salt. Examples of the organic compound used to form the organic silver salt include triazoles, tetrazoles, imidazoles, indazoles, thiazoles, thiadiazoles, azaindenes, and aliphatic, aromatic, or aromatic compounds having a mercapto group as a substituent. Heterocyclic compounds can be mentioned. Further, silver salts of carboxylic acids and silver acetylene can also be used as organic silver salts.
Two or more organic silver salts may be used in combination. The organic silver salt is used in an amount of 10 ^{-5 to} 10 mol, preferably 10 ^{-4 to} 1 mol, per 1 mol of silver halide.

[Reducing Agent] The reducing agent has a function of reducing silver halide or a function of accelerating polymerization of a polymerizable compound (or crosslinking of a crosslinkable polymer). As the reducing agent, hydrazines, hydroquinones, catechols,
p-aminophenols, p-phenylenediamines,
3-pyrazolidones, 3-aminopyrazoles, 4-amino-5-pyrazolones, 5-aminouracils, 4,
5-dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- or p-sulfonamidophenols, o- or p-sulfonamidonaphthols, o- or p-acylaminophenols,
2-Sulfonamide indanones, 4-sulfonamido-5-pyrazolones, 3-sulfonamidoindoles, sulfonamidopyrazolobenzimidazoles, sulfonamidopyrazolotriazoles and α-sulfonamidoketones are used.

The reducing agent is described in JP-A-61-183640,
Nos. 61-188535, 61-228441, 62-70836, 62-86354 and 62-
No. 86355, No. 62-206540, No. 62-26
No. 4041, No. 62-109437, No. 63-254
442, JP-A-1-267536 and 2-1417
No. 56, No. 2-141775, No. 2-207254
And JP-A-2-262662 and JP-A-2-269352 (including those described as a developing agent or a hydrazine derivative). As for the reducing agent,
"The Theory of the Photographic Proces" by T. James
s "Fourth Edition, pp. 291-334 (1977), Research Disclosure, Vol. 170, No. 17029.
No. 9-15, (June 1978), and the same magazine, Vo
l.176, No.17643, pp.22-31, (1978
December). Further, Japanese Patent Application Laid-Open No. 62-210
As in the light-sensitive material described in Japanese Patent No. 446, a reducing agent precursor that releases the reducing agent under heating conditions or in contact with a base may be used instead of the reducing agent.

The basic reducing agent which forms a salt with an acid can be used in the form of a salt with a suitable acid. Two or more reducing agents may be used in combination. The interaction of two or more reducing agents is, first, to promote the reduction of silver halide (or organic silver salt) by so-called superadditivity, and second, to promote silver halide (or organic silver salt). It is conceivable that the oxidized form of the first reducing agent generated by the reduction of the compound causes polymerization of the polymerizable compound (or suppresses the polymerization) via an oxidation-reduction reaction with another coexisting reducing agent. The reducing agent is preferably used in an amount of 0.1 to 10 mol, more preferably 0.25 to 2.5 mol, per 1 mol of silver halide.

[Fogging inhibitor, silver development accelerator, stabilizer]
In order to improve photographic properties, additives such as an antifogging agent, a silver development accelerator for accelerating silver development, and a stabilizer may be added to any of the layers. Examples thereof include mercapto compounds (described in JP-A-59-111636), azoles and azaindenes (described in Research Disclosure No. 17643, pages 24 to 25 (1978)), and carboxylic acids containing nitrogen. And phosphoric acids (described in JP-A-59-168442), cyclic amides (described in JP-A-61-151841), thioethers (described in JP-A-62-151842), and polyethylene glycol derivatives (described in JP-A-62-151842). No. -151843), thiols (described in JP-A-62-151844), acetylene compounds (described in JP-A-62-87957), and sulfonamides (described in JP-A-62-1782).
No. 32). As the silver development accelerator or the antifoggant, an aromatic ring (carbon ring or heterocyclic) mercapto compound (described in JP-A-6-313967) is particularly preferred. Aromatic heterocyclic mercapto compounds, particularly mercaptotriazole derivatives, are more preferred. The mercapto compound may be added to the light-sensitive material as a mercapto silver compound (silver salt). These compounds may be used in an amount of 10 ^-7 mol to 1 mol per mol of silver halide.
Range of moles.

[Hydrophilic polymer] The photosensitive layer contains the above-mentioned polymer mixture as a hydrophilic polymer. Hydrophilic layer other than photosensitive layer (adhesive layer, image formation accelerating layer, intermediate layer)
Also include a hydrophilic polymer as a binder. The hydrophilic polymer is a polymer compound having a hydrophilic group or a hydrophilic bond in a molecular structure. Examples of the hydrophilic group include a carboxyl, an alcoholic hydroxyl group, a phenolic hydroxyl group, a sulfone, a sulfonamide group, a sulfonimide group, an amide group, and an alkylamino group. Examples of the hydrophilic bond include a urethane bond, an ether bond and an amide bond. As the hydrophilic polymer, a natural, synthetic or semi-synthetic polymer compound can be used. The hydrophilic polymer is described in JP-A-5-249667.

As described above, in the photosensitive layer, it is preferable that gelatin is adhered to silver halide grains and that a hydrophilic synthetic polymer is used as a binder. Gelatin is used as a protective colloid in the preparation of silver halide emulsions. Denatured gelatin or partially decomposed gelatin may be used. The use of gelatin in the preparation of silver halide emulsions results in the gelatin adhering to the silver halide grains. The amount of gelatin in the photosensitive layer is preferably 0.01 to 10% by weight of the amount of the hydrophilic synthetic polymer.

Polyvinyl alcohol is a particularly preferred hydrophilic (synthetic) polymer. Polyvinyl alcohol is
Various saponification degrees can be used. However, in order to reduce the oxygen permeability, the degree of saponification is preferably 70% or more, and more preferably 80% or more. Copolymerized modified polyvinyl alcohol can also be used.
Copolymerization modification is a method of saponifying a copolymer of vinyl acetate and another monomer to synthesize a modified polyvinyl alcohol. Examples of monomers to be copolymerized include ethylene, higher vinyl carboxylate, higher alkyl vinyl ether, methyl methacrylate and acrylamide.

Also, post-modified polyvinyl alcohol can be used. The post-modification is a method in which a compound having reactivity with a hydroxyl group of polyvinyl alcohol is used to modify polyvinyl alcohol by a polymer reaction after synthesis. Specifically, the hydroxyl group of polyvinyl alcohol is modified by etherification, esterification, or acetalization. Furthermore, crosslinked polyvinyl alcohol can also be used. As the cross-linking agent, an aldehyde, a methylol compound, an epoxy compound, a diisocyanate, a divinyl compound, a dicarboxylic acid, or an inorganic cross-linking agent (eg, boric acid) can be used. The molecular weight of the water-soluble polymer is preferably in the range of 3000 to 500,000.

[Polymerizable Compound] The polymerizable compound is preferably a compound (monomer or oligomer) having an ethylenically unsaturated group capable of undergoing addition polymerization by free radicals. The ethylenically unsaturated polymerizable compound is described in JP-A-5-249667. Examples of ethylenically unsaturated polymerizable compounds include acrylic acid and salts thereof, acrylic esters, acrylamides, methacrylic acid and salts thereof, methacrylic esters, methacrylamides, maleic anhydride, maleic esters, Examples include itaconic esters, styrenes, vinyl ethers, vinyl esters, N-vinyl heterocycles, allyl ethers and allyl esters. Acrylic esters or methacrylic esters are particularly preferred. Specific examples of (meth) acrylates include pentaerythritol tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, polyester (meth) acrylate and polyurethane (meth) acrylate Can be mentioned. Two or more ethylenically unsaturated polymerizable compounds may be used in combination.

[Hydrophobic polymer] The hydrophobic polymer preferably has crosslinkability. For crosslinking, it is preferable to introduce an ethylenically unsaturated bond into the main chain or side chain of the molecule. The crosslinkability may be introduced by copolymerization. Examples of the polymer having an ethylenically unsaturated bond in the main chain of the molecule include poly-1,4-butadiene, poly-1,4
-Isoprene, natural and synthetic rubbers. Examples of the polymer having an ethylenically unsaturated bond in the side chain of the molecule include a polymer of an ester or amide of acrylic acid or methacrylic acid, and a residue of the ester or amide (R of —COOR or —CONHR)
Is a polymer having an ethylenically unsaturated bond. Examples of the residue having an ethylenically unsaturated bond (R described above) include-(CH ₂ ) _n -CR ¹ = CR ² R ³ ,-(CH ₂ O) _n -CH ₂
CR ¹ = CR ² R ³ ,-(CH ₂ CH ₂ O) _n -CH ₂ CR ¹ = CR ² R ³ ,-(CH ₂ ) _n -NH-C
OO-CH ₂ CR ¹ = CR ² R ³ ,-(CH ₂ ) _n -O-CO-CR ¹ = CR ² R ³ and-(CH
₂ CH ₂ O) ₂ -X (R ^{1 to} R ³ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group,
An alkoxy group, an aryloxy group, R ¹ and R ² or
R ³ may combine with each other to form a ring, and n is 1 to 10
And X is a dicyclopentadienyl residue).

Specific examples of the ester residue include -CH ₂ CH = CH
₂ (described in JP-B-7-21633), -CH ₂ CH ₂ O-CH ₂ C
H = CH ₂ , -CH ₂ C (CH ₃ ) = CH ₂ , -CH ₂ CH = CH-C ₆ H ₅ , -CH ₂ CH ₂ OCOC
H = CH-C ₆ H ₅ , -CH ₂ CH ₂ -NHCOO-CH ₂ CH = CH ₂ and -CH ₂ CH ₂ O-
X (X is a dicyclopentadienyl residue) is included. Specific examples of the amide _{residue, -CH 2 CH = CH 2,} -CH 2 CH 2 -1-Y (Y
Are included cyclohexene residue) and _{-CH 2 CH 2 -OCO-CH =} CH 2. In the crosslinkable polymer as described above, a free radical (a polymerization initiation radical or a growing radical in the polymerization process of an ethylenically unsaturated polymerizable compound) is added to the unsaturated bonding group, and the polymer is directly or polymerically unsaturated between the polymers. Addition polymerization is carried out via a polymerization chain of the polymerizable compound, and a crosslink is formed between polymer molecules to be cured. Alternatively, free radicals abstract atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to unsaturated bond groups) to form polymer radicals, which combine with each other to form crosslinks between polymer molecules. Being cured.

As the non-crosslinkable (non-crosslinkable or weakly crosslinkable) polymer, a saturated aliphatic residue or an aromatic residue may be used in place of the above-mentioned residue (R) having an ethylenically unsaturated bond. , Polymethacrylic esters (eg, polymethyl methacrylate, polybenzyl methacrylate), polyacrylamide, and polymethacrylamide. Examples of other non-crosslinkable polymers include polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, polymethacrylonitrile, polyethylene, polyvinylpyridine, polyvinylimidazole, polyvinylbutyral, polyvinylformal, polyvinylpyrrolidone, chlorinated It includes polyethylene, chlorinated polypropylene, polyester, polyamide, polyurethane, polycarbonate, cellulose ether (eg, ethyl cellulose) and cellulose ester (eg, cellulose triacetate, cellulose diacetate, cellulose acetate butyrate).

It is preferable to use an acidic group introduced into the above-mentioned hydrophobic (and crosslinkable or non-crosslinkable) polymer. Examples of the acidic group include a carboxyl group, an acid anhydride group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, and a sulfonimide group. Carboxyl groups are particularly preferred. Specifically, a monomer of (meth) acrylic acid, styrene sulfonic acid or maleic anhydride can be copolymerized during the synthesis of the polymer, and these acidic groups can be incorporated into the polymer of the curable layer. The molar content of the monomer having an acidic group in the copolymer is preferably from 1 to 60%, more preferably from 5 to 50%, and most preferably from 10 to 40%. The molecular weight of the hydrophobic polymer is preferably in the range of 1,000 to 500,000. Two or more polymers may be used in combination.

[Base Precursor] As the base precursor, precursors of various inorganic bases and organic bases (decarboxylation type, thermal decomposition type, reaction type, complex salt forming type or dissociation type) can be used. Examples of decarboxylation type base precursors include salts of organic acids and bases which can be decarboxylated by heating (JP-A-63-316760, 64-68746).
Nos. 59-180537 and 61-31343
No. 1). Examples of the pyrolytic base precursor include a urea compound (Japanese Patent Application Laid-Open No.
3-96159). Examples of the reactive base precursor include transition metal acetylide (described in JP-A-63-25208). Examples of complex salt-forming base precursors include basic metal compounds which are hardly soluble in water (JP-A-1-32882).
Publication No.). Examples of dissociable base precursors include alkali metal salts of organic acids (eg,
Sodium acetate, a sodium salt of a polymer having an acidic group). The base precursor is 50
It is preferred to produce the base at ~ 200 ° C,
More preferably, the base is formed at 60 ° C. The base precursor is 0.1 to 2 per mole of silver halide.
It is preferably used in a range of 0 mol, more preferably in a range of 0.2 to 10 mol.

[Heat Development Accelerator] In order to carry out the heat development at a lower temperature or in a shorter time, a heat development accelerator may be added to any layer of the photosensitive material. As the thermal development accelerator, a compound having a plasticizing effect at room temperature or upon heating with respect to a binder used in any layer of the photosensitive material, or a compound having no plasticizing effect but capable of melting in the layer by heating is used. Can be used. It is considered that the thermal development accelerator promotes thermal development by promoting the diffusion of the reactant in the photosensitive material or by promoting the reaction itself. Examples of the compound having a plasticizing action include “Plastic Additives” Taiseisha, P21-63; “Plastics Additiv 2nd Edition” (Plastics Additiv)
es, 2nd Edition, Hanser Publishers) Chapter 5, 251
Pp. 296 to 296 can be used. Preferred thermal development accelerators include polyethers (eg, polyethylene glycol, polypropylene glycol), polyhydric alcohols (eg, glycerin, hexanediol), sugars (eg, sorbitol), formate esters, ureas (eg, urea, diethyl) Urea, ethylene urea), amides (eg, acetamide, propionamide, malonamide), sulfamides, sulfonamides, urea resins and phenol resins. Two or more thermal development accelerators can be used in combination. Further, it may be added in two or more layers. The addition amount of the thermal development accelerator is preferably 0.05 to 2 g / m ² , and more preferably 0.1 to 1 g / m ² .

[Colorant] A colorant can be added to a light-sensitive material for the purpose of preventing halation and irradiation, coloring a cured image or adjusting sensitivity (absolute sensitivity or spectral sensitivity). As the colorant, known pigments and dyes can be used as long as they do not significantly hinder the curing reaction or significantly deteriorate the photosensitivity and developability of silver halide. When a colorant is added to prevent halation and irradiation, those capable of absorbing light in the photosensitive wavelength region of silver halide are preferred. When fine particles are added to the photosensitive layer, light may be scattered by the fine particles. In that case, it is preferable to further add a coloring agent for preventing irradiation to the photosensitive layer. As a coloring agent, JP-A-5-249667,
Pigments, dyes or colloidal silver described in Color Index Handbook and Dye Handbook (edited by The Society of Synthetic Organic Chemistry, 1970) can be used. Dyes for preventing irradiation which have little effect on the sensitivity of silver halide are disclosed in JP-B-41
No.-20389, No.43-3504, No.43-131
No. 68 and JP-A-2-39042, and U.S. Pat. Nos. 3697037 and 3423207, and British Patents 1030392 and 1100054. Further, a coloring agent may be added to the adhesive layer. When fine particles are added to the adhesive layer, light scattering by the fine particles may occur. The coloring agent added to the adhesive layer has a function of preventing light scattering. The amount of the colorant added is preferably in the range of 0.01 to 2 g / m ² ,
The range is more preferably from 5 to 1 g / m ² .

[Development Stopping Agent] Various development stopping agents can be used for the purpose of always obtaining a constant image with respect to the processing temperature and the processing time during thermal development. A development terminator is a compound that immediately neutralizes a base or reacts with a base to reduce the base concentration in a layer and stop development after proper development, or a compound that interacts with silver and a silver salt to suppress development. is there.
Specifically, an acid precursor that releases an acid upon heating,
An electrophilic compound that undergoes a substitution reaction with a coexisting base upon heating, or a nitrogen-containing heterocyclic compound, a mercapto compound, and a precursor thereof can be used. The thermal development terminator is described in JP-A-62-253159 and JP-A-2-2-159.
Nos. 42447 and 2-262661.

[Surfactant] A known surfactant may be added to any of the layers. Any of a nonionic activator, an anionic activator, a cationic activator and a fluorine activator can be used. For the surfactant, see JP-A-2-195356.
There is a description in the publication. Sorbitans, polyoxyethylenes and fluorinated surfactants are particularly preferred.

[Matting Agent] A matting agent is added to the back layer or the image formation accelerating layer of the photosensitive material for the purpose of reducing the tackiness of the front or back surface of the photosensitive material and preventing adhesion when the photosensitive materials are stacked. be able to. As the matting agent, inorganic or organic solid particles that can be dispersed in a water-soluble polymer are used. Examples of matting materials include:
Oxides (eg, silicon dioxide), alkaline earth metal salts, natural polymers (eg, starch, cellulose) and synthetic polymers can be mentioned. The particle size of the matting agent is 0.
A range of 5 to 50 μm is preferred. The coating amount of the matting agent is preferably in the range of 0.1 to 1 g / m ² .

[Polymerization Inhibitor] In order to prevent polymerization of the polymerizable compound during storage of the light-sensitive material, a known polymerization inhibitor can be used. Examples of polymerization inhibitors include nitrosamines, ureas, thioureas, thioamides, phenols and amines.

[Exposure Step] The image exposure is performed with light having a wavelength corresponding to the spectral sensitivity of silver halide. The wavelength is visible light,
Near-ultraviolet light and near-infrared light are generally used, but X-rays and electron beams may be used. Examples of light sources include lamps such as tungsten lamps, halogen lamps, xenon lamps, xenon flash lamps, mercury lamps, carbon arc lamps, and various lasers (eg, semiconductor lasers, helium neon lasers, argon ion lasers, helium cadmium lasers, YAG laser), light emitting diode, cathode ray tube and the like.

The exposure amount is generally 0.001 to 1000.
μJ / cm ² , preferably 0.01 to 100 μJ / c
m ² . When the support is transparent, exposure can be performed through the support from the back side of the support. In the process of forming a latent image of silver halide, the sensitivity tends to change under the influence of temperature and humidity during exposure. Therefore, it is desirable that the temperature and humidity of the atmosphere of the photosensitive material and the light source be controlled within a certain range. Adjusting means of the image recording apparatus for achieving the above object are described in JP-A-3-63143 and JP-A-3-63637.

[Development Step] The development of the photosensitive material is carried out by heating (heat development) by heating. The thermal development can be performed by a method in which the photosensitive material is brought into close contact with a heated object (eg, a metal plate or a metal roller), a method in which the photosensitive material is immersed in a heated liquid, or a method in which infrared light is irradiated. The surface of the photosensitive material may be opened to the air and heated from the support side, or the surface may be closely contacted with a heated object and heated while the air is shut off. If you open the surface into the air and heat it,
Since the oxygen in the air may proceed into the photosensitive material and inhibit the curing reaction, use the above-described polymer having a low oxygen permeability as the binder for the surface-side layer such as the image formation promoting layer. Is preferred. Heating temperature is 60 to 2
The temperature is in the range of 00 ° C, more preferably 100 to 160 ° C. The heating time ranges from 1 to 180 seconds, more preferably from 5 to 60 seconds. Before or after the exposure step, the photosensitive material may be preheated at a lower temperature or for a shorter time than the main heating conditions. Post-heating may be performed after the main heating or after the removal step (described later).

[Removing Step] In order to form an image by removing the uncured portion (non-image portion), it is preferable to remove the uncured portion by elution. Before removing the uncured portion, it is preferable to remove the photosensitive layer, the image formation accelerating layer and other hydrophilic layers by washing or mechanical peeling.
It is preferable to use an alkaline eluate as the eluate. Examples of the alkaline compound used in the alkaline eluate include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, sodium phosphate,
Potassium phosphate, ammonia and amino alcohols (eg, monoethanolamine, diethanolamine, triethanolamine) are included. As a solvent for the eluate, water is preferable. If necessary, an organic solvent may be added to water. As the organic solvent, alcohols or ethers are preferable. Examples of alcohols include lower alcohols (eg, methanol, ethanol, propanol, butanol), alcohols having an aromatic group (eg, benzyl alcohol, phenethyl alcohol), and polyhydric alcohols (eg, ethylene glycol, diethylene glycol,
Triethylene glycol, polyethylene glycol) and amino alcohols (eg, monoethanolamine,
Diethanolamine, triethanolamine). Examples of ethers include cellosolves. The eluate may contain a surfactant, an antifoaming agent, and other various additives as necessary.

[Use of photosensitive material] The photosensitive material can be used for forming a hard copy or a relief image or for producing a printing plate. In particular, it is suitable for producing a printing plate.

[0054]

[Example 1] [Preparation of aluminum support] A surface of an aluminum plate having a thickness of 0.30 mm was coated with a nylon brush and a pumice stone (4).
(00 mesh) with a water suspension, and then thoroughly washed with water. Next, the film was immersed in a 10% by weight aqueous solution of sodium hydroxide at 70 ° C. for 60 seconds for etching, and then washed with running water. It was neutralized and washed with a 20% by weight aqueous solution of nitric acid, and then washed with water. The obtained aluminum plate was subjected to a sine wave alternating waveform current (condition: voltage at anode: 12.7 V, ratio of electricity at cathode to electricity at anode: 0.8, electricity at anode: 160 coulomb / dm ² ). The electrolytic surface roughening treatment was performed in a 1% by weight aqueous nitric acid solution. The surface roughness of the obtained plate was 0.6 μm (Ra indication). Following this treatment, a desmutting treatment was performed at 55 ° C. for 2 minutes in a 13% by weight aqueous sulfuric acid solution. Next, in a 20% by weight aqueous sulfuric acid solution, the current density was set to ^{2 A} / dm ² so that the thickness became 2.7 g / dm ^2.
Anodizing treatment was performed under dm ² conditions. The obtained aluminum plate was placed in a 3% by weight aqueous solution of sodium silicate at 70 ° C.
For 20 minutes. This was washed with water and dried to prepare an aluminum support.

[Formation of Silver Nitrate Layer] A 0.02% by weight aqueous solution of silver nitrate was applied to the above-mentioned support with a wheeler (200 rpm).
m, 20 seconds) and dried at 100 ° C. for 1 minute.

"Preparation of pigment dispersion" A pigment dispersion having the following composition was prepared.

────────────────────────────────────Pigment dispersion liquid──────── ──────────────────────────── Chromophthal Red A2B 6.90 g Allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio = 80/20) ) 5.73 g cyclohexanone 12.90 g propylene glycol monomethyl ether 74.47 g ─

"Formation of a curable layer" The following coating solution was applied on a silver nitrate layer and dried to form a curable layer having a dry film thickness of 1.3 µm.

塗布 Coating liquid for curable layer────── ────────────────────────────── 0.23 g of pentaerythritol tetraacrylate allyl methacrylate / methacrylic acid copolymer (copolymerization molar ratio = 70 / 30) 20% by weight propylene glycol monomethyl ether solution 2.46 g The above pigment dispersion 4.47 g 0.56% by weight methanol solution of the following additives 0.54 g Fluorinated nonionic surfactant (MEGAFAC F-176PF) 1.00 g of methyl ethyl ketone 0.62 g propylene glycol monomethyl ether 0.50 g ───────

[0060]

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"Preparation of silver halide emulsion" A reaction vessel containing gelatin, potassium bromide and water and heated to 55 ° C was placed in a reaction vessel.
1. The following thioether compound was added to the amount of silver nitrate added.
It was added in an amount equivalent to 0 × 10 ⁻³ mol. PAg of reaction vessel
While maintaining the value at 9.2, an aqueous solution of silver nitrate and an aqueous solution of potassium bromide containing rhodium ammonium chloride at a molar ratio of rhodium to the total amount of potassium iodide and silver nitrate of 4 × 10 ⁻⁸ mol were used. And pAg control by a double jet method to form silver iodobromide grains. Next, at 55 ° C. and pAg = 8.9, a silver nitrate aqueous solution and a molar ratio of iridium to silver of 1 × 10 5 were used.
A core / shell type silver iodobromide emulsion having the following composition was prepared by adding two steps of a potassium bromide solution to which hexachloroiridate (III) was added so as to be ^-7 mol by a double jet method.

[0062]

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Core: silver iodobromide (silver iodide content: 7.5 mol%) Shell: pure silver bromide Core / shell: 3/7 (silver molar ratio) Average silver iodide content: 2.3 Mol% average particle size: 0.28 μm

The obtained emulsion grains were monodispersed and contained 98% of the total number of grains within ± 40% of the average grain size. Next, the emulsion was subjected to desalting treatment, and then the desalting treatment was performed to adjust the pH to 6.5 and the pAg to 9.0. While stirring the emulsion at 50 ° C., the following spectral sensitizing dye A
And B in methanol (molar ratio: A: B = 2:
1) was added in an amount equivalent to 8 × 10 ⁻⁴ mol / mol Ag in total of the dye, and the mixture was kept for 20 minutes to prepare a silver halide emulsion.

[0065]

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"Preparation of photosensitive layer coating solution" A photosensitive layer coating solution having the following composition was prepared.

<< Coating solution for photosensitive layer >> ８１ Polyvinyl alcohol with a saponification degree of 81% (PVA-405, manufactured by Kuraray Co., Ltd.) 10% by weight aqueous solution 4.64 g 5% by weight aqueous solution of the following surfactant 0.80 g 10% by weight aqueous solution of the following reducing agent 7.12 g Phosphate buffer solution (potassium dihydrogen phosphate 0.025 mol / l and phosphorus 1.60 g of the above-mentioned silver halide emulsion (diluted 4.3 times with water) 1.76 g of water 38.8 g of potassium bromide The coating solution has a conductivity of 450 μS / cm. (40 ° C) ──────────────

[0068]

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[0069]

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"Preparation of Base Precursor Dispersion" Using a Dynomill disperser, 250 g of the following base precursor powder was mixed with polyvinyl alcohol (P) having a saponification degree of 81%.
VA-405, manufactured by Kuraray Co., Ltd.)
Dispersed in 0 g. The particle size of the base precursor was 0.5 μm or less.

[0071]

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"Preparation of coating solution for image formation promoting layer" A coating solution for image formation promoting layer having the following composition was prepared.

塗布 Coating solution for image formation accelerating layer─────ポ リ ビ ニ ル Polyvinyl alcohol with a saponification degree of 81% (PVA-405, manufactured by Kuraray Co., Ltd.) 5.00 g of a 10 wt% aqueous solution of the above-mentioned base precursor 0.53 g of a 5 wt% aqueous solution of the above surfactant 0.13 g ──────────────────── ────────────────

[Preparation of Overcoat Layer Coating Solution] An overcoat layer coating solution having the following composition was prepared.

塗布 Coating solution for overcoat layer──────ポ リ ビ ニ ル Polyvinyl alcohol with a saponification degree of 98% (PVA-105, manufactured by Kuraray Co., Ltd.) 10% by weight aqueous solution 100g 5% by weight aqueous solution of the above surfactant 2g ──

[Preparation of Photosensitive Material] Using a slide hopper type coating apparatus, the coating solutions for the photosensitive layer, the image formation accelerating layer and the overcoat layer were extruded on the curable layer in this order. did. The coating amount was adjusted so that the photosensitive layer had a thickness of 2.0 μm, the image formation promoting layer had a thickness of 1.3 μm, and the overcoat layer had a thickness of 3.0 μm. Thus, a photosensitive material was produced.

(Measurement of Conductivity of Photosensitive Layer Coating Solution) At 40 ° C., a measuring device (TOAC) was used at a concentration of 10% by weight of solids.
M-60S electrode CG-511B, Toa Dempa Kogyo Co., Ltd.
Was used for the measurement.

(Evaluation of Stability of Photosensitive Layer Coating Solution) The photosensitive layer coating solution was allowed to stand at 35 ° C. for 24 hours. Thereafter, the sedimentation state of the silver halide was examined. The results are shown in Table 1. A: No sedimentation (homogeneous liquid) B: Sedimentation at the bottom of the container

(Evaluation of Dispersibility of Silver Halide Particles) The photosensitive layer was observed with an electron microscope, and the dispersion state of the silver halide particles was evaluated based on the average particle size of aggregates of the silver halide particles.

(Image formation) Using a 500 W tungsten lamp, pass through a 670 nm band filter.
The photosensitive material was image-exposed at 3 looks for 3 seconds. next,
The support surface of the photosensitive material was heated by pressing a hot plate heated to 155 ° C. The photosensitive material was washed with water to remove the overcoat layer, the image formation accelerating layer and the photosensitive layer. Alkaline eluate (DP-4, manufactured by Fuji Photo Film Co., Ltd.
After diluting it twice and adding 1% by weight of the above-mentioned nonionic surfactant), etching treatment was performed at 30 ° C. for 20 seconds, followed by washing with water. As a result, a good polymer relief image was formed on the exposed area. Was. When the obtained relief image was attached to a printing machine as a printing plate and printed, a good printed matter was obtained.

Example 2 A photosensitive material was prepared in the same manner as in Example 1, except that the amount of potassium bromide was adjusted so that the conductivity of the coating solution for the photosensitive layer was 750 μS / cm (40 ° C.). It was prepared and evaluated. The results are shown in Table 1. When an image was formed using the produced photosensitive material in the same manner as in Example 1, a good polymer relief image was obtained in the exposed area.

Comparative Example 1 A photosensitive material was prepared in the same manner as in Example 1 except that the amount of potassium bromide was adjusted so that the conductivity of the coating solution for the photosensitive layer was 950 μS / cm (40 ° C.). It was prepared and evaluated. The results are shown in Table 1. When an image was formed using the produced photosensitive material in the same manner as in Example 1, the gradation was slightly soft.

[Comparative Example 2] The amount of potassium bromide was determined by adjusting the conductivity of the photosensitive layer coating solution to 3200 μS / cm (40 ° C.).
A photosensitive material was prepared and evaluated in the same manner as in Example 1 except that the adjustment was performed so as to be as follows. The results are shown in Table 1. When an image was formed in the same manner as in Example 1 using the prepared photosensitive material, no image was formed.

[0084]

[Table 1] Table 1 ──────────────────────────────────── Photosensitive material Coating liquid conductivity Coating Liquid stability Dispersion of silver halide grains ──────────────────────────────────── Example 1 450 μS / cmA 0.28 μm (no aggregation) Example 2 750 μS / cm A 0.28 μm (no aggregation) Comparative Example 1 950 μS / cm B 0.91 μm (aggregation) Comparative Example 2 3200 μS / cm C 5.20 μm ( Remarkable aggregation) ────────────────────────────────────

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a typical layer configuration of a photosensitive material of the present invention.

[Explanation of symbols]

 Reference Signs List 1 aluminum support 2 curable layer 21 polymerizable compound 22 crosslinkable polymer 3 photosensitive layer 31 silver halide 32 gelatin 33 reducing agent 34 hydrophilic synthetic polymer 35 potassium bromide 4 image formation accelerating layer 41 base precursor 42 hydrophilic polymer 5 Overcoat layer 51 Hydrophilic polymer

Claims (5)

[Claims] 1. A curable layer containing a polymerizable compound or a crosslinkable polymer on a support, a photosensitive layer in which silver halide grains having gelatin adhered are dispersed in a hydrophilic synthetic polymer, and a base precursor. An image formation accelerating layer containing a hydrophilic polymer is laminated in this order, and the curable layer or the photosensitive layer is a photosensitive material containing a reducing agent. A photosensitive material, wherein the electric conductivity of the dissolved solution is less than 800 μS / cm. 2. The photosensitive material according to claim 1, wherein the amount of gelatin in the photosensitive layer is 0.01 to 10% by weight of the amount of the hydrophilic synthetic polymer. 3. The method according to claim 1, wherein the hydrophilic synthetic polymer in the photosensitive layer comprises 7
2. The light-sensitive material according to claim 1, which is a polyvinyl alcohol having a saponification degree of 0 to 99.9%. 4. A step of providing a curable layer containing a polymerizable compound or a crosslinkable polymer on a support, and silver halide grains having gelatin adhered on the curable layer in a hydrophilic synthetic polymer. A photosensitive material comprising a step of simultaneously applying a dispersed photosensitive layer coating solution and an image formation promoting layer coating solution containing a base precursor and a hydrophilic polymer, wherein the conductivity of the photosensitive layer coating solution is less than 800 μS / cm. Manufacturing method. 5. The method according to claim 4, wherein the conductivity of the coating solution for the photosensitive layer is adjusted by adding potassium bromide to the coating solution for the photosensitive layer.