JP2001290277A - Method for producing planographic printing plate and silver halide photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a relief image having high lipophilic property by tanning development. SOLUTION: The objective planographic printing plate is produced by successively carrying out a step for imagewise exposing a silver halide photosenlitive material having a silver halide-gelatin emulsion layer on a hydrophilic base and containing lipophilic compound-containing microcapsules dispersed in the emulsion layer or an arbitrarily disposed hydrophilic polymer layer, a step for subjecting the photosensitive material to tanning development to harden the gelatin in the exposed part, a step for leaching out the unhardened gelatin in the unexposed part to form a relief image of the hardened gelatin and a step for pressing the formed relief image to burst the microcapsules in the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for making a lithographic printing plate by tanning development and a silver halide light-sensitive material used therefor.

[0002]

2. Description of the Related Art Tanning development is a phenomenon that has long been known in the art of silver halide photography (for example,
TH James, The Theory of the Photographic Proces
s, 4thedition, pages 326-327). Pyrogallol,
When a silver halide photosensitive material is developed using a phenolic developing agent such as hydroquinone or catechol, the gelatin contained in the silver halide emulsion layer hardens in the exposed areas. This tanning effect occurs because the oxidation product of the phenolic developing agent has a hardening effect on gelatin. Tanning development has the effect of softening the image of a normal silver halide photograph. That is, since the gelatin in the exposed area is hardened, the penetration of the developing solution in the exposed area is suppressed, whereby the progress of development is suppressed.

A method has been proposed in which the hardening of gelatin in an exposed portion is used for forming a relief image. If the uncured gelatin in the unexposed area is eluted, a relief image of the cured gelatin can be formed. The relief image of hardened gelatin can be used as a lithographic printing plate.
If a relief image of hardened gelatin is formed on a hydrophilic support (aluminum plate), the surface of the support exposed by removal functions as a hydrophilic region, and the relief image functions as a lipophilic region. In lithographic printing, an image is printed by dampening water adhering to a hydrophilic area and oil-based ink adhering to a lipophilic area. A method of utilizing a relief image of hardened gelatin as a lithographic printing plate is described in JP-A-53-135.
No. 702, No. 54-49202, No. 54-15250
No. 2, No. 55-12625, JP-A-4-324866
Nos. 5-289228 and British Patent 15
Nos. 67844, 1571155 and 1590058
No. is described in each specification.

[0004]

The method of using a relief image of hardened gelatin as a lithographic printing plate is that silver halide, which is an optical sensor, has higher sensitivity than other lithographic printing plate making methods, There is an advantage that plate making can be performed with simple processing. When a relief image of hardened gelatin is used as a lithographic printing plate, the exposed surface of the support functions as a hydrophilic region and the relief image functions as a lipophilic region. Hardened gelatin is not strongly lipophilic, even though it is relatively lipophilic compared to the support surface (hardened gelatin is
It is more commonly understood as a hydrophilic substance). In lithographic printing using a fountain solution, the hardened gelatin easily absorbs the fountain solution and swells or softens. For the above reasons, when a relief image of hardened gelatin is used as a lithographic printing plate, the hardened gelatin has a problem of insufficient lipophilicity (ink receptivity) and durability (printing durability).

JP-A-53-135702 and JP-A-54-1
No. 52502, No. 55-12625, JP-A-4-32
The methods described in JP-A Nos. 4866 and 5-289228 propose that the hardened gelatin be treated (heat treatment, light irradiation treatment, chemical treatment) after image formation in order to improve ink receptivity. However, there is a problem that when the hardened gelatin is heated, the adhesiveness between the hardened gelatin and the support decreases. Further, in order to irradiate light to the extent that the ink receptivity of the hardened gelatin is improved, a powerful light irradiation device is required. The chemical treatment involves problems of toxicity of the chemical substances used and an insufficient treatment effect.

JP-A-54-49202 and British Patents 1,567,844, 1,571,155 and 159
No. 0058 proposes to add an lipophilic substance to a silver halide emulsion layer or an overcoat layer in order to improve ink receptivity. When a lipophilic substance was added to the silver halide emulsion layer, the lipophilic substance was dispersed or emulsified in the silver halide emulsion. Depending on the surfactant used for dispersion or emulsification, problems such as sedimentation and aggregation of the silver halide emulsion and deterioration of the stability of the photosensitive material occur. On the other hand, in the case where a lipophilic substance is added to the overcoat layer, if an amount effective for improving the lipophilicity of an image is added, the permeability of the developer decreases, and the development efficiency and the crosslinking efficiency deteriorate. When a lipophilic substance is dispersed using a dispersant or a surfactant and added to the overcoat layer, the dispersant diffuses into the silver halide emulsion layer during storage after the photosensitive material is prepared, and the halogenated compound is dispersed. Causing silver agglomeration,
The development efficiency and the crosslinking efficiency deteriorate. An object of the present invention is to form a relief image having high lipophilicity by tanning development.

[0007]

The above objects have been achieved by the following (1) to (4) lithographic printing plate making methods and the following (5) silver halide photosensitive material. (1) A silver halide gelatin emulsion layer is provided on a hydrophilic support, and microcapsules are dispersed in the silver halide gelatin emulsion layer or an optional hydrophilic polymer layer. Image-exposing the silver halide light-sensitive material contained in the capsule; tanning developing the silver halide light-sensitive material to harden the gelatin in the exposed area; A step of forming a relief image; and a step of pressing the formed relief image to rupture the microcapsules in this order.

(2) The plate making method according to (1), wherein the lipophilic compound is a monomer having a polymerizable group, and the step of polymerizing the monomer is carried out after the step of rupture of the microcapsules. (3) The plate making method according to (2), wherein the photopolymerization initiator is further contained in a microcapsule, and the step of polymerizing the monomer by light irradiation is performed. (4) The plate making method according to (2), wherein the thermal polymerization initiator is further contained in the microcapsule, and the step of polymerizing the monomer by heating is performed. (5) A silver halide photosensitive material having a silver halide gelatin emulsion layer on a hydrophilic support, wherein the microcapsules are dispersed in the silver halide gelatin emulsion layer or an optional hydrophilic polymer layer. And a lipophilic compound is contained in a microcapsule.

[0009]

According to the present invention, the lipophilic compound is contained in microcapsules and added to the silver halide emulsion,
The relief image was successfully made lipophilic without causing any problems in the silver halide emulsion layer. Lipophilic compounds are:
Because it is isolated from the silver halide emulsion by the capsule wall,
Lipophilic compounds have no effect on silver halide emulsions.
Also, the dispersion of microcapsules is easier than the dispersion or emulsification of lipophilic compounds and does not require the use of surfactants. In the present invention, after the formation of the relief image is completed, the microcapsules are ruptured to make the relief image lipophilic. Accordingly, the relief image can be made highly lipophilic, without causing the lipophilic compound to cause a problem in the silver halide emulsion layer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Plate Making Method FIG. 1 is a schematic sectional view of a silver halide photosensitive material used in the present invention. FIG.
As shown in (1), a silver halide gelatin emulsion layer (2) is provided on a hydrophilic support (1). The silver halide gelatin emulsion layer contains silver halide grains (21), gelatin (22) and microcapsules (23). The microcapsule (23) contains a lipophilic compound and a photopolymerization initiator.

FIG. 2 is a schematic cross-sectional view of a silver halide photosensitive material during image exposure. As shown in FIG. 2, when the silver halide photosensitive material is irradiated with light (L1), a latent image (21a) is formed on the silver halide grains in the exposed portions. In contrast, there is no change in the unexposed portions of the silver halide grains (21). Note that the photopolymerization initiator contained in the microcapsules has a significantly lower sensitivity than the silver halide grains (21). Therefore, the photopolymerization initiator does not act on the light used for image exposure.

FIG. 3 is a schematic cross-sectional view of a silver halide photosensitive material in tanning development. As shown in FIG.
When the silver halide photosensitive material after image exposure is immersed in a tanning developer (D), the silver halide particles in the exposed area are developed to form a silver image (21b). The oxidized product (quinone) of the tanning developer generated during the development crosslinks the gelatin (22a) in the exposed area. In contrast, there is no change in the unexposed portion of the gelatin (22).

FIG. 4 is a schematic cross-sectional view of a silver halide photosensitive material during elution. As shown in FIG. 4, when the silver halide photosensitive material after the tanning development is treated with the eluate (D), only the unexposed portions of the silver halide gelatin emulsion layer are eluted. Silver halide gelatin emulsion layer (2
a) has cross-linked gelatin (22a),
It remains on the hydrophilic support (1) to form a relief image.

FIG. 5 is a schematic cross-sectional view of a silver halide photosensitive material under pressure. As shown in FIG. 5, when pressure (P) is applied to the eluted silver halide photosensitive material, the microcapsules (23a) rupture, and the contained lipophilic compound and photopolymerization initiator are removed from the exposed portion. To the silver halide gelatin emulsion layer. Thereby, the silver halide gelatin emulsion layer in the exposed portion becomes the lipophilic layer (2b), and the difference from the surface of the hydrophilic support (1) becomes clear.

FIG. 6 is a schematic cross-sectional view of a silver halide light-sensitive material in the overall exposure. As shown in FIG. 6, the photopolymerization initiator acts to polymerize the lipophilic compound. As a result, the silver halide gelatin emulsion layer in the exposed area becomes the lipophilic cured layer (2c), and the durability (printing durability) in printing can be improved. In addition, when using a thermal polymerization initiator instead of a photopolymerization initiator, in the last processing step (FIG. 6),
The entire surface is heated instead of the entire surface exposure.

[Lipophilic compound] In the present invention, the lipophilic compound is contained in a microcapsule and added to the silver halide gelatin emulsion layer. The lipophilic compound is preferably liquid at normal temperature (25 ° C.). Preferably, the lipophilic compound is substantially insoluble in water (having a solubility in water at room temperature of less than 1% by weight). The lipophilic compound preferably has a polymerizable group. The polymerizable group is preferably a ring-opening polymerizable group or an addition polymerizable group, more preferably an addition polymerizable group, and most preferably an ethylenically unsaturated polymerizable group. The lipophilic compound preferably has a plurality of polymerizable groups. Ethylenically unsaturated polymerizable compounds include acrylic acid and its salts, acrylic acid esters, acrylamide, methacrylic acid and its salts, methacrylic acid esters, methacrylamide, maleic anhydride, maleic acid esters,
Includes itaconic esters, styrene, styrene derivatives, vinyl ethers, vinyl esters, N-vinyl heterocyclic compounds, allyl ethers and allyl esters.
Acrylic esters and methacrylic esters are preferred. The alcohol forming an ester with acrylic acid or methacrylic acid is preferably a polyhydric alcohol.

Examples of the acrylate ester include n-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, furfuryl acrylate, ethoxyethoxyethyl acrylate, dicyclohexyloxyethyl acrylate, nonylphenyloxyethyl acrylate, and hexanediol diacrylate. Acrylate, butanediol diacrylate,
Neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, polyoxyethylenated bisphenol A diacrylate, hydroxy polyether polyacrylate,
Includes polyester acrylates and polyurethane acrylates. Examples of methacrylates include methyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, butanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate and polyoxyalkylene. Bisphenol A dimethacrylate is included.

[Polymerization Initiator] When the lipophilic compound has a polymerizable group, it is preferable to further contain the polymerization initiator in microcapsules. The polymerization initiator includes a photopolymerization initiator and a thermal polymerization initiator. Various known compounds can be used as the photopolymerization initiator and the thermal polymerization initiator.
Instead of the photopolymerization initiator or the thermal polymerization initiator, a compound (eg, imine, amine, sulfinic acid) that can initiate polymerization without external energy application may be used. However, a polymerization initiator that does not require external energy application needs to be placed outside the microcapsule containing the lipophilic compound having a polymerizable group (may be contained in another microcapsule). The polymerization initiator is
0.1 to 120 of the amount of the lipophilic compound having a polymerizable group
It is preferably used in a range of 1% by weight, more preferably in a range of 1 to 10% by weight.

[Microcapsules] It is preferable to use a relatively hydrophilic polymer for the wall material for forming the microcapsules. Examples of relatively hydrophilic polymers include:
Gelatin, gum arabic, starch, sodium alginate, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, polyamide, polyester, polyurethane, polyurea and polyethyleneimine are included. Microcapsules can be prepared by a phase separation method (described in each of U.S. Pat. Nos. 2,800,457 and 2,800,458) and an interfacial polymerization method (Japanese Patent Publication No. 38-19574, 42).
-446, 42-771), in situ
u method (JP-B-36-9168, JP-A-51-9097)
No., each publication), a melting dispersion cooling method (UK Patent 9528)
07 and 930422) or by a spray drying method (US Pat. No. 3,111,407 and British Patent 930422).
Interfacial polymerization is particularly preferred.

Use of hydrophilic polymers (eg, gelatin, gum arabic, casein, starch, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone) as polymers (protective colloids in the emulsification of lipophilic compounds) used in the production of microcapsules. Is preferred. It is particularly preferred to use polyvinyl alcohol. The microcapsule may further contain an organic solvent. Organic solvent has a high boiling point (150 ° C or higher)
It is preferred that Examples of the organic solvent include alkyl naphthalenes, alkyl biphenyls, alkylidene biphenyls and phosphate esters. The amount of the organic solvent used is preferably 1 to 30% by weight of the amount of the lipophilic compound. The average particle size of the microcapsules is 0.
And preferably from 0.1 to 1 μm.
m is more preferable. Microcapsules are
It is preferably from 5 to 70% by weight, more preferably from 10 to 50% by weight, based on the coating amount of the silver halide gelatin emulsion layer.

[Silver halide gelatin emulsion layer] The silver halide gelatin emulsion layer contains gelatin as a binder. In tanning development, a relief image can be formed by hardening gelatin. In addition to gelatin, it is possible to perform tanning development on a hydrophilic polymer having an amide bond or a primary amino group (eg, a protein other than gelatin, polyacrylamide). However, tanning development is usually performed on gelatin. Other hydrophilic polymers (eg,
Polyvinyl pyrrolidone, starch, albumin, polyvinyl alcohol, acacia, hydroxyethyl cellulose) and gelatin may be used in combination. The coating amount of silver halide is preferably 0.01 to 5 g / m ² , more preferably 0.03 to 1 g / m ² , and more preferably 0.05 to 0.3 g / m ^{2 in} terms of silver. Is most preferred. The thickness of the silver halide emulsion layer is preferably from 0.07 to 13 μm, more preferably from 0.2 to 5 μm.

As silver halide, silver chloride, silver bromide,
Any grain of silver iodide, or silver chlorobromide, silver chloroiodide, silver iodobromide, or silver chloroiodobromide can 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. Potato-shaped,
Spherical, plate-like and plate-like crystal forms are included. 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 grain size of the silver halide.
Fine particles of 0.01 μm or less can also be used. Meanwhile, 1
Large particles of about 0 μm can also be used. With respect to grain size distribution, monodisperse grains are preferred over polydisperse emulsions.
Monodispersed emulsions are described in U.S. Pat. Nos. 3,574,628 and 3,655,394 and British Patent 1,413,748. The crystal structure of silver halide grains is
It may be uniform or the inside and the outside may have different halogen compositions. 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 solution of a halide 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).

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.

Fine particles of a lipophilic resin can be added to the silver halide emulsion layer to enhance the lipophilicity of the relief image. The fine particles of the lipophilic resin also have the effect of increasing the mechanical strength of the relief image. Examples of lipophilic resins include polyester, polyamide, phenol-aldehyde resin, polyvinyl chloride, polyurethane, epoxy resin, silicon resin, alkylphenol resin, ketone resin, alkyd resin, polyamine, polystyrene, polyacrylate, and rosin-modified maleic resin. , Rosin-modified fumaric acid resin, polyvinyl acetate, hydroxypropyl methylcellulose,
Rosin modified phenolic resin and hexahydrophthalate are included. Polystyrene, polyacrylate, polyvinyl acetate, polyurethane, hydroxypropyl methylcellulose and hexahydrophthalate are preferred.
Further, a photosensitive resin (a photopolymerizable polymer or a photocrosslinkable polymer) may be used as the lipophilic resin. Two or more types of lipophilic resins may be used in combination. The fine particles of the lipophilic resin preferably have an average particle size of 0.01 to 5 μm. There is no particular limitation on the shape of the fine particles.

In order to improve photographic characteristics, additives such as an antifogging agent, a silver development accelerator for accelerating silver development, and a stabilizer may be added to the silver halide emulsion layer. Examples thereof include mercapto compounds (JP-A-59-111636).
Azoles and azaindenes (Research Disclosure No. 17643, 24-25)
Page (1978)), carboxylic acids and phosphoric acids containing nitrogen (described in JP-A-59-168442),
Cyclic amide (described in JP-A-61-151841),
Thioethers (described in JP-A-62-151842), polyethylene glycol derivatives (JP-A-62-1)
No. 51843), thiols (JP-A-62-15)
No. 1844), acetylene compounds (Japanese Unexamined Patent Publication No. Sho 62)
-87957) and sulfonamide (described in JP-A-62-178232). As a silver development accelerator or an antifoggant, an aromatic ring (carbon ring or heterocyclic) mercapto compound (Japanese Patent Laid-Open No.
-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).
The amount of these compounds used is 1 to 1 mole of silver halide.
It is in the range of ^0-7 mol to 1 mol.

A tanning developer may be added to the silver halide emulsion layer. Known surfactants may be added to the silver halide emulsion layer. Any of a nonionic activator, an anionic activator, a cationic activator and a fluorine activator can be used. The surfactant is described in JP-A-2-195356. Sorbitans, polyoxyethylenes and fluorinated surfactants are particularly preferred.

[Hydrophilic support] As the support, paper, synthetic paper, synthetic resin (eg, polyethylene, polypropylene,
Polystyrene) laminated paper, 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. Aluminum plates, plastic films, paper and synthetic paper are preferred. Further, a composite sheet in which an aluminum sheet is laminated on a polyethylene terephthalate film is also preferable. Aluminum plates and plastic films are more preferred, and aluminum plates are particularly preferred. When a hydrophobic material such as a plastic film is used, it can be used as a hydrophilic support by providing a hydrophilic undercoat layer (described later).

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 components constituting the undercoat layer include polymers (eg, gelatin, casein, polyvinyl alcohol, ethyl cellulose, phenolic resin, styrene-maleic anhydride resin, polyacrylic acid); amines (eg, monoethanol Amines, diethanolamine, triethanolamine, tripropanolamine) and their hydrochlorides, oxalates or phosphates; monoaminomonocarboxylic acids (eg, aminoacetic acid, alanine); oxyamino acids (eg, serine, threonine, dihydroxyamine) 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-hydroxy) Phenylglycine, Eniruaranin, anthranyl); aliphatic amino acid (e.g., sulfamic acid,
(Cyclohexylsulfamic acid); and (poly) aminopolyacetic acid (eg, ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid,
Hydroxyethylethylenediamineacetic 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 plastic film is used as the support, it is preferable to add hydrophilic fine particles (eg, silica powder) to the hydrophilic undercoat layer instead of sanding the aluminum support.

[Arbitrarily Provided Layer] The layer optionally provided in the silver halide light-sensitive material is preferably a hydrophilic layer containing a hydrophilic polymer as a binder, similarly to the silver halide emulsion layer. It is more preferable that the layer be a binder. A tanning developer can be added to the optional hydrophilic layer.

A back layer containing a matting agent or an overcoat layer containing a matting agent for the purpose of reducing the tackiness of the front or back surface of the silver halide light-sensitive material and preventing adhesion when the silver halide light-sensitive materials are stacked. Can be provided on the silver halide photosensitive material. As the matting agent, inorganic or organic solid particles that can be dispersed in a water-soluble polymer are used. Examples of materials for the matting agent include oxides (eg, silicon dioxide), alkaline earth metal salts, natural polymers (eg, starch, cellulose) and synthetic polymers. The particle size of the matting agent is preferably in the range of 0.5 to 50 μm. The application amount of the matting agent is 0.
It is preferably in the range of 1 to 1 g / m ² .

A protective layer is provided on the silver halide emulsion layer,
The lipophilic resin fine particles described above may be added to the protective layer.
The protective layer containing the lipophilic resin fine particles is 0.01 to 5 μm
Preferably, it has a thickness of 0.2 to 2 μm. The protective layer preferably has voids between the lipophilic resin particles to such an extent that the developer can penetrate. The hydrophilic layer optionally provided may contain the above-mentioned microcapsules, antifoggant, silver development accelerator for promoting silver development, a stabilizer or a surfactant.

[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. Exposure doses generally range from 0.001 to 1000 μJ / cm ² , preferably from 0.01 to 100 μJ / cm ² . When the support is transparent, exposure can be performed through the support from the back side of the support.

[Tanning Development Step] The tanning development of the silver halide photosensitive material is performed using a developer. The tanning developer is usually added to the developer. The developer is generally an alkaline solution. The pH of the developer is preferably 9 or more. Examples of the alkaline substance used for adjusting the pH include sodium hydroxide, potassium hydroxide, sodium phosphate, potassium phosphate, lithium phosphate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, and ammonia. As a solvent for the developer, water is preferable. If necessary, an organic solvent may be added to water. The temperature of the developer is preferably 5 to 40 ° C., and 20 to 35 ° C.
It is more preferable that the temperature is ° C. The development time is preferably from 10 seconds to 10 minutes, and more preferably from 20 seconds to 3 minutes. After the development processing, the lipophilicity of the image area may be enhanced by processing with a liquid containing a mercapto compound (described in JP-A-4-324866). Further, an acidic treatment or a fixing treatment may be performed.

As the tanning developer, compounds having a benzenediol ring or a benzenetriol ring (eg,
Pyrogallol, hydroquinone, catechol). A polymer containing a repeating unit having a benzenediol ring or a benzenetriol ring in a side chain can also be used as a tanning developer. The use amount of the tanning developer is preferably 0.01 to 1 mol / mol Ag, and more preferably 0.03 to 1 mol Ag. The amount of the tanning developer added to the tanning developer is preferably 10 ^{-5 to} 10 ^-1 mol / l.

In addition to the tanning developer, an auxiliary developer can be used. Examples of auxiliary developing agents include amidole, metol and aminophenol. Metol is particularly preferred. The auxiliary developing agent can be added to a tanning developer or a silver halide photosensitive material.
The amount of the auxiliary developer is 5 to 20 times the amount of the tanning developer.
It is preferably 0 mol%.

[Elution Step] The silver halide photosensitive material after the tanning development is immersed in hot water and rubbed on the surface to elute the uncured gelatin in the unexposed area to form a relief image of the cured gelatin. Can be. The temperature of the hot water is preferably 40 to 70 ° C. The surface of the photosensitive material may be rubbed with a sponge or a brush.

[Pressing Step] The formed relief image is ruptured by applying pressure to the microcapsules. The pressure treatment can be easily performed by a known method. Pressurization may be performed while heating.

[Overall exposure step or overall heating step] When a lipophilic compound having a polymerizable group is polymerized with a photopolymerization initiator, the formed relief image is irradiated with light over the entire surface. The irradiation light is preferably visible light or ultraviolet light, and more preferably ultraviolet light. The exposure amount is determined according to the sensitivity of the photopolymerization initiator. When a lipophilic compound having a polymerizable group is polymerized with a thermal polymerization initiator, the formed relief image is entirely heated. The heating temperature is preferably from 50 to 200 ° C.

[0045]

[Example 1] "Preparation of aluminum support" JI having a thickness of 0.24 mm
The surface of the aluminum plate according to SA-1050 was grained with a nylon brush and an aqueous suspension of pamistone (400 mesh), 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. 20% by weight
And then washed with water. The obtained aluminum plate was subjected to a square wave alternating current (condition:
The voltage at the time of the anode is 12.7 V, the ratio of the amount of electricity at the cathode to the amount of electricity at the anode is 0.9, and the amount of electricity at the anode is 160 coulomb / dm.
^{Using 2} ), electrolytic surface roughening treatment was performed in a 1% by weight nitric acid aqueous solution containing 0.5% by weight of aluminum nitrate. The surface roughness of the obtained plate was 0.6 μm (Ra indication). Subsequent to this treatment, the substrate was immersed in a 1% by weight aqueous sodium hydroxide solution at 40 ° C. for 30 seconds, and then treated in a 30% by weight aqueous sulfuric acid solution at 55 ° C. for 1 minute. Next, when the thickness is 2.
Anodizing treatment was carried out in a 20% by weight aqueous sulfuric acid solution using a direct current at a current density of 2 A / dm ^{2 so} as to obtain 5 g / dm ² . This was washed with water and dried to prepare a support. The prepared support was used as a No. 3 sodium silicate (SI
O _2: 28 to 30 wt%, Na ₂ O: 9 to 10 wt%,
Fe: 0.02% by weight or less 2.5% by weight aqueous solution (p
H: 11.2) at 70 ° C. for 13 seconds and washed with water.
The amount of silicate measured by X-ray fluorescence analysis was 10 mg / m
^{Was 2} .

"Preparation of silver halide emulsion" In a vessel containing gelatin, potassium bromide and water and heated to 55 ° C, the following thioether compound was further added in an amount of 2.0 × 10 ^-3 mol based on the added amount of silver nitrate. A considerable amount was added. Reaction vessel p
While maintaining the Ag value at 9.2, an aqueous solution of silver nitrate and an aqueous solution of potassium bromide containing rhodium ammonium chloride in a molar ratio of rhodium to the total amount of potassium iodide and silver nitrate of 4 × 10 ⁻⁸ mol were used. With pAg
Silver iodobromide grains were formed by the control double jet method. Subsequently, 55 ° C., pAg = 8.
In step 9, a double-stage double jet method was used to add a silver nitrate aqueous solution and a potassium bromide solution to which hexachloroiridate (III) was added in a molar ratio of iridium to silver of 1.0 × 10 ⁻⁷ mol. Thus, a core / shell type silver iodobromide emulsion having the following composition was prepared.

[0047]

Embedded image

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 all grains within ± 40% of the average grain size. Then, after desalting the emulsion, a methanol solution of a spectral sensitizing dye A below (5 × 10 ^- 3M / l) and a spectral sensitizing dye B in methanol in the following (5 × 10
^- The 3M / l), with respect to emulsion per mole of silver nitrate equivalent, respectively 100ml added, 6.2 pH, pAg
Was adjusted to 8.7. Further, gold / sulfur sensitization was performed using sodium thiosulfate and chloroauric acid to prepare an aqueous silver halide emulsion. Solid concentration of emulsion: 29.6% by weight Gelatin concentration of emulsion: 3.5% by weight

[0050]

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[0051]

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“Preparation of Microcapsule Dispersion” 100
ml homogenizer, polyvinyl alcohol (PVA)
217E, manufactured by Kuraray Co., Ltd.). Separately, 22 g of pentaerythritol tetraacrylate (ATMMT, manufactured by Shin-Nakamura Chemical Co., Ltd.), 0.5 g of benzoin ethyl ether and a polyvalent isocyanate compound (Takenate D110N, manufactured by Takeda Pharmaceutical Co., Ltd.)
15 g were mixed to obtain a homogeneous solution. The resulting solution is
The mixture was transferred to a 0 ml homogenizer and emulsified at 10,000 rpm for 5 minutes. The obtained emulsion was transferred to a 300 ml cup, and while stirring with a propeller, a solution obtained by diluting 50 g of a 1% by weight aqueous solution of diethylenetriamine with 50 g of water was added, the temperature was raised to 30 ° C., and the mixture was stirred for 30 minutes. The temperature was further raised to 65 ° C., and heating and stirring were continued for 3 hours. The obtained microcapsule dispersion was diluted with water to a solid content concentration of 20% by weight. The average particle size of the microcapsules is
It was 0.5 μm.

"Formation of silver halide gelatin emulsion layer" The following coating solution was prepared and coated on an aluminum support.
After drying, a silver halide gelatin emulsion layer having a dry film thickness of 1.2 μm was provided. Thus, a silver halide photosensitive material was produced.

<< Coating solution of silver halide gelatin emulsion layer >> ───────────────────────────────── The above silver halide emulsion 10 g 10% by weight aqueous solution of gelatin 11 g Capsule dispersion 5g water 10g ────────────────────────────────────

"Preparation of tanning developer" A solution A and a solution B having the following compositions were prepared, and both were mixed and maintained at 25 ° C, and used at that temperature.

液 Liquid A ───────── ─────────────────────────── Pyrogallol 3 g Metol 1 g Citric acid 1 g Water 500 g ────────────── ──────────────────────

液 Liquid B ─────────カ リ ウ ム Potassium carbonate 200g Potassium iodide 1g Water 500g ────────────── ──────────────────────

(Image formation) A light of 670 nm was separated by a sharp cut interference filter with a light emission time of 10 ^-4 seconds by a xenon flash using a silver halide photosensitive material, and the energy on the photosensitive material surface was 2 μJ / cm ² . Control wedge (Fuji Photo Film Co., Ltd.)
Was brought into close contact with each other to perform image exposure. The image-exposed silver halide photosensitive material was immersed in a tanning developer for 30 seconds.
Then, it was washed with running water at 45 ° C. for 15 seconds. The surface of the silver halide light-sensitive material was lightly rubbed with a sponge to remove an unexposed portion of the silver halide emulsion layer and dried, whereby a relief image having a uniform film surface on the support was obtained. Next, the obtained relief image was covered with a polyethylene terephthalate film and pressed through a laminator (temperature: 70 to 100 ° C.). Further, light irradiation was performed for 5 minutes using a 400 W high-pressure mercury lamp. Thus, a lithographic printing plate was made. The lithographic printing plate was wetted with water and rubbed with an IP ink (manufactured by Fuji Photo Film Co., Ltd.) to examine the ink receptivity. As a result, the image area (relief image) received the ink well. The lithographic printing plate was mounted on an offset printing machine (RYOBI3200CCD, manufactured by Ryobi Co., Ltd.), and printing was performed to check the printing durability. As a result, it was possible to print 10,000 sheets or more.

Examples 2 to 5 The lipophilic compounds shown in Table 1 were used in place of pentaerythritol tetraacrylate (lipophilic compound) used for preparing the microcapsule dispersion, except that the same amounts were used. As in Example 1,
A silver halide photosensitive material was prepared and evaluated. First result
It is shown in the table.

Comparative Example 1 A silver halide photosensitive material was prepared and evaluated in the same manner as in Example 1, except that the microcapsule dispersion was not added to the coating solution for the silver halide gelatin emulsion layer. The results are shown in Table 1.

[0061]

[Table 1] Table 1 ハ ロ ゲ ン Halogenated ink silver photosensitive material Oily Compound Receptive Printing Durability Example 1 Pentaerythritol Tetraacrylate Good 10,000 sheets or more Example 2 Dipentaerythritol hexaacrylate Good 10,000 sheets or more Example 3 Trimethylolpropane triacrylate Good 10,000 sheets or more Example 4 Tris (acryloxyester) isocyanurate Good 10,000 sheets or more Example 5 Urethane acrylate Good 10,000 sheets or more Comparative Example 1 None Insufficient Less than 100 sheets ─

Examples 6 to 10 In place of benzoin ethyl ether (photopolymerization initiator) used for preparing the microcapsule dispersion, 2,2'-azobis (2-acetoxy-4-methylpentane) was used. Examples 1-5 except for
In the same manner as above, silver halide photosensitive materials were prepared and evaluated. The results are shown in Table 2.

[0063]

[Table 2] Table 2 ──────────────────────────────────── Halogenated ink silver photosensitive material Oily Compound Receptive Printing Durability Example 6 Pentaerythritol Tetraacrylate Good 10,000 sheets or more Example 7 Dipentaerythritol hexaacrylate Good 10,000 sheets or more Example 8 Trimethylolpropane triacrylate Good 10,000 sheets or more Example 9 Tris (acryloxyester) isocyanurate Good 10,000 sheets or more Example 10 Urethane acrylate good 10,000 sheets or more ────────────────────────────────────

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a silver halide photosensitive material used in the present invention.

FIG. 2 is a schematic cross-sectional view of a silver halide photosensitive material during image exposure.

FIG. 3 is a schematic cross-sectional view of a silver halide photosensitive material in tanning development.

FIG. 4 is a schematic cross-sectional view of a silver halide photosensitive material during elution.

FIG. 5 is a schematic cross-sectional view of a silver halide photosensitive material under pressure.

FIG. 6 is a schematic cross-sectional view of a silver halide photosensitive material during overall exposure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hydrophilic support 2 Silver halide gelatin emulsion layer 2a Silver halide gelatin emulsion layer of exposed part 2b Silver halide gelatin emulsion layer of exposed part which became lipophilic layer 2c Halogen of exposed part which became lipophilic hardened layer Silver halide gelatin emulsion layer 21 Silver halide grains 21a Latent image of silver halide grains 21b Silver image 22 Gelatin 22a Crosslinked gelatin 23 Microcapsules 23a Ruptured microcapsules D Tanning developer L1 Image exposure light L2 Image exposure light P Pressure S Eluate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 514 G03F 7/004 514 7/027 7/027 7/40 7/40 F term (reference) 2H016 AD04 BC00 2H023 CE03 2H025 AA12 AB03 AC01 AD01 BC13 BC34 BC43 BH03 CA00 CA15 CB03 DA10 FA17 FA30 FA39 2H084 AA30 BB04 CC05 2H096 AA07 BA05 BA17 CA03 EA02 GA08 HA03 HA30

Claims (5)

[Claims] 1. A lipophilic compound comprising a silver halide gelatin emulsion layer on a hydrophilic support, and microcapsules dispersed in the silver halide gelatin emulsion layer or an optional hydrophilic polymer layer. Exposing the silver halide light-sensitive material contained in the microcapsules to image exposure; tanning the silver halide light-sensitive material to harden the gelatin in the exposed area; eluting and hardening the uncured gelatin in the unexposed area A step of forming a relief image of gelatin; and a step of pressurizing the formed relief image to rupture the microcapsules in this order. 2. The plate making method according to claim 1, wherein the lipophilic compound is a monomer having a polymerizable group, and a step of polymerizing the monomer is performed after the step of rupture of the microcapsules. 3. The plate making method according to claim 2, wherein a photopolymerization initiator is further contained in the microcapsules, and a step of polymerizing the monomer by light irradiation is performed. 4. The plate making method according to claim 2, wherein the thermal polymerization initiator is further contained in the microcapsules, and the step of polymerizing the monomer by heating is carried out. 5. A silver halide photosensitive material having a silver halide gelatin emulsion layer on a hydrophilic support, wherein the microcapsules are dispersed in the silver halide gelatin emulsion layer or in an optional hydrophilic polymer layer. A silver halide photosensitive material characterized in that a lipophilic compound is contained in a microcapsule.