JP2001305739A - Method for producing planographic printing plate and planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a relief image of hardened gelatin suitable for utilization as a planographic printing plate and having high lipophilic property and high strength. SOLUTION: The objective planographic printing plate is produced by successively carrying out a step for imagewise exposing a planographic printing original plate with a silver halide-gelatin emulsion layer on a hydrophilic base, a step for subjecting the original plate to tanning development with a hydrophobic benzenediol or benzenetriol compound substituted by a 5-40C aliphatic substituent or a 7-40C aromatic substituent to harden the gelatin in the exposed part and a step for leaching out the unhardened gelatin in the unexposed part to form the objective relief image of hardened gelatin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for making a lithographic printing plate by tanning development.

[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
And JP-A-5-289228.

[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 common to treat them as hydrophilic substances). 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 problems of insufficient lipophilicity (ink receptivity) and low strength (press life).

JP-A-53-135702 and JP-A-54-4
Nos. 9202, 54-152502, 55-126
No. 25, JP-A-4-324866 and 5-28922
The method described in each publication of No. 8 proposes to perform a treatment (heating treatment, light irradiation treatment, chemical treatment) on the hardened gelatin after image formation in order to improve ink receptivity and printing durability. However, when post-processing is performed after image formation, the advantage that plate making can be performed with simple processing is lost. In addition, the heat treatment has a problem that the adhesiveness between the hardened gelatin and the support decreases. In the light irradiation process, a powerful light irradiation device is required. The chemical treatment has a problem that the toxicity of the chemical substance used and the treatment effect are insufficient. The object of the present invention is
The purpose is to form a relief image of hardened gelatin having high lipophilicity and high strength suitable for use as a lithographic printing plate.

[0006]

The above object has been achieved by the following (1) and (2) lithographic printing plate making methods and the following (3) lithographic printing plate. (1) A step of imagewise exposing a lithographic printing plate precursor having a silver halide gelatin emulsion layer on a hydrophilic support, and tanning development of the lithographic printing plate precursor using a developing agent represented by the following formula (I) to expose the exposed portion Lithographic printing, wherein a step of hardening the gelatin and a step of eluting an unexposed portion of the uncured gelatin to form a relief image of the hardened gelatin are performed in this order to make a lithographic printing plate. Plate making method:

[0007]

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Wherein n is 1 or 2; and R is an aliphatic group having 5 to 40 carbon atoms, an aromatic group having 7 to 40 carbon atoms, and 5 carbon atoms. To 40
Aliphatic acyl groups, aromatic acyl groups having 7 to 40 carbon atoms, aliphatic oxycarbonyl groups having 5 to 40 carbon atoms, aromatic oxycarbonyl groups having 7 to 40 carbon atoms, carbon atoms Is an aliphatic acyloxy group having 5 to 40, an aromatic acyloxy group having 7 to 40 carbon atoms,
An aliphatic substituted carbamoyl group having 5 to 40 carbon atoms or an aromatic substituted carbamoyl group having 7 to 40 carbon atoms]. (2) The method of making a lithographic printing plate according to (1), wherein the developer is represented by the following formula (Ia), (Ib), (Ic) or (Id):

[0009]

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Wherein R is an aliphatic group having 5 to 40 carbon atoms, an aromatic group having 7 to 40 carbon atoms, an aliphatic acyl group having 5 to 40 carbon atoms, Is an aromatic acyl group having 7 to 40 carbon atoms, an aliphatic oxycarbonyl group having 5 to 40 carbon atoms, an aromatic oxycarbonyl group having 7 to 40 carbon atoms, and an aliphatic acyloxy group having 5 to 40 carbon atoms. An aromatic acyloxy group having 7 to 40 carbon atoms, an aliphatic substituted carbamoyl group having 5 to 40 carbon atoms or an aromatic substituted carbamoyl group having 7 to 40 carbon atoms]. (3) A lithographic printing plate having a relief image of hardened gelatin on a hydrophilic support, wherein the hardened gelatin is formed by a hardening reaction of gelatin by an oxidized form of the developing agent represented by the above formula (I). A lithographic printing plate characterized in that:

[0011]

The present inventor has started to improve the tanning developer instead of adding post-processing as proposed in the prior art. As a result of the research, conventional tanning developers (pyrogallol, hydroquinone, catechol)
By introducing an aliphatic substituent having 5 to 40 carbon atoms or an aromatic substituent having 7 to 40 carbon atoms into a benzenediol ring or a benzenetriol ring corresponding to A hardened gelatin having high strength was successfully formed. The improved lipophilicity and strength of the hardened gelatin has substantially made it possible to utilize the relief image of the hardened gelatin as a lithographic printing plate.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION [Tanning developer] In the present invention, a compound represented by the following formula (I) is used as a tanning developer.

[0013]

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In the formula (I), n is 1 or 2. When n is 1, the relationship between the two hydroxyl groups is preferably ortho (catechol derivative) or para (hydroquinone derivative). When n is 2, the three hydroxyl groups are preferably adjacent (pyrogallol derivative).

In the formula (I), R represents 5 carbon atoms.
To 40 aliphatic groups, aromatic groups having 7 to 40 carbon atoms, aliphatic acyl groups having 5 to 40 carbon atoms, aromatic acyl groups having 7 to 40 carbon atoms, and 5 carbon atoms To 40 aliphatic oxycarbonyl groups, aromatic oxycarbonyl groups having 7 to 40 carbon atoms, aliphatic acyloxy groups having 5 to 40 carbon atoms, and 7 to 4 carbon atoms
0 aromatic acyloxy group, aliphatic substituted carbamoyl group having 5 to 40 carbon atoms, or 7 to 4 carbon atoms.
0 is an aromatic substituted carbamoyl group. The number of carbon atoms means the total number of carbon atoms including the substituent. The aliphatic group preferably has 6 to 35 carbon atoms, more preferably 7 to 30 carbon atoms, and 9 to 25 carbon atoms.
Is more preferable, and most preferably 11 to 22. The aliphatic group may be unsaturated (having a double bond or a triple bond). The aliphatic group may have a cyclic structure or a branch. The aliphatic group may have a substituent (eg, a halogen atom, an aromatic group, amino, an aliphatic substituted amino group, an alkoxy group). The aromatic group preferably has 7 to 35 carbon atoms, more preferably 8 to 30 carbon atoms,
It is more preferably 9 to 25, and 10 to 22.
Is most preferred. The aromatic group is a substituent (eg,
(Halogen atom, aliphatic group, amino, aliphatic substituted amino group, alkoxy group).

The number of carbon atoms of the aliphatic acyl group is preferably from 6 to 35, more preferably from 7 to 30, further preferably from 9 to 25, and more preferably from 11 to 22. Most preferred. The aliphatic acyl group may be unsaturated (having a double bond or a triple bond). The aliphatic acyl group may have a cyclic structure or a branch. The aliphatic acyl group may have a substituent (eg, a halogen atom, an aromatic group, amino, an aliphatic substituted amino group, an alkoxy group). The number of carbon atoms of the aromatic acyl group is preferably from 7 to 35, more preferably from 8 to 30, further preferably from 9 to 25, and most preferably from 10 to 22. The aromatic acyl group may have a substituent (eg, a halogen atom, an aliphatic group, amino, an aliphatic substituted amino group, an alkoxy group). The number of carbon atoms of the aliphatic oxycarbonyl group is preferably from 6 to 35, more preferably from 7 to 30, still more preferably from 9 to 25, and most preferably from 11 to 22. . The aliphatic oxycarbonyl group may be unsaturated (having a double bond or a triple bond). The aliphatic acyl group may have a cyclic structure or a branch. The aliphatic oxycarbonyl group may have a substituent (eg, a halogen atom, an aromatic group, amino, an aliphatic substituted amino group, an alkoxy group). The aromatic oxycarbonyl group has 7 carbon atoms.
To 35, more preferably 8 to 30, still more preferably 9 to 25, and most preferably 10 to 22. The aromatic oxycarbonyl group may have a substituent (eg, a halogen atom, an aliphatic group, amino, an aliphatic substituted amino group, an alkoxy group).

The number of carbon atoms in the aliphatic acyloxy group is preferably from 6 to 35, more preferably from 7 to 30, further preferably from 9 to 25, and more preferably from 11 to 22. Most preferred. The aliphatic acyloxy group may be unsaturated (having a double bond or a triple bond). The aliphatic acyloxy group may have a cyclic structure or a branch. The aliphatic acyloxy group may have a substituent (eg, a halogen atom, an aromatic group, amino, an aliphatic substituted amino group, an alkoxy group). The aromatic acyloxy group preferably has 7 to 35 carbon atoms, and has 8 to 30 carbon atoms.
Is more preferable, 9 to 25 is further preferable, and 10 to 22 is most preferable. The aromatic acyloxy group may have a substituent (eg, a halogen atom, an aliphatic group, amino, an aliphatic substituted amino group, an alkoxy group). The aliphatic substituted carbamoyl group preferably has 6 to 35 carbon atoms, more preferably 7 to 30 carbon atoms, and more preferably 9 to 25 carbon atoms.
Is more preferable, and most preferably 11 to 22. The aliphatic substituted carbamoyl group may be unsaturated (even if it has a double bond or a triple bond).
Good. The aliphatic acyl group may have a cyclic structure or a branch. The aliphatic substituted carbamoyl group may have a substituent (eg, a halogen atom, an aromatic group, amino, an aliphatic substituted amino group, an alkoxy group). The number of carbon atoms of the aromatic-substituted carbamoyl group is preferably from 7 to 35, more preferably from 8 to 30, further preferably from 9 to 25, and most preferably from 10 to 22. . The aromatic-substituted carbamoyl group may have a substituent (eg, halogen atom, aliphatic group, amino, aliphatic-substituted amino group, alkoxy group).

Catechol, hydroquinone or pyrogallol derivatives represented by the following formulas (Ia), (Ib), (Ic) or (Id) are particularly preferred tanning developers.

[0019]

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In the formulas (Ia), (Ib), (Ic) and (Id), R is an aliphatic group having 5 to 40 carbon atoms, an aromatic group having 7 to 40 carbon atoms, a carbon atom. An aliphatic acyl group having 5 to 40 carbon atoms, an aromatic acyl group having 7 to 40 carbon atoms, an aliphatic oxycarbonyl group having 5 to 40 carbon atoms, and an aromatic oxycarbonyl having 7 to 40 carbon atoms Group, an aliphatic acyloxy group having 5 to 40 carbon atoms, an aromatic acyloxy group having 7 to 40 carbon atoms, an aliphatic substituted carbamoyl group having 5 to 40 carbon atoms, or an aliphatic acyloxy group having 5 to 40 carbon atoms It is an aromatic substituted carbamoyl group. The definition and examples of each group are the same as those in formula (I). Hereinafter, examples of the developer represented by the formula (I) will be described.

[0021]

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[0022]

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[0023]

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[0040]

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[0061]

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[0062]

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[0063]

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Two or more tanning developers may be used in combination. A tanning developer represented by the formula (I) and a known tanning developer (eg, hydroquinone, t-butylhydroquinone, catechol, phenylcatechol, pyrogallol, nordihydrguaiaretinic acid,
3′3′-Tetramethyl-5,6,5 ′, 6′-tetrahydroxyspiro-bis-indane). When used in combination, the tanning developer represented by the formula (I) accounts for 50 to 99% by weight of the total amount of the tanning developer.
Is more preferably 55 to 95% by weight, and most preferably 60 to 90% by weight. The tanning developer is used by adding it to a lithographic printing original plate or a tanning developer.

When the tanning developer is dissolved, emulsified, or dispersed in a silver halide gelatin emulsion layer or a coating liquid for an optional hydrophilic layer (eg, hydrophilic protective layer), the tanning developer is added to the lithographic printing plate precursor. Good. The tanning developer can be generally dissolved in a coating solution for a silver halide gelatin emulsion layer or a hydrophilic layer. The amount added to the lithographic printing plate precursor is preferably 0.01 to 1 mol / mol Ag, and more preferably 0.03 to 1 mol Ag. When added to the tanning developer, the tanning developer may be dissolved, emulsified or dispersed in the developer. The amount added to the developer is preferably 10 ^{-5 to} 10 ^-1 mol / l.

[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 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 plastic film). Components constituting the undercoat layer include polymers (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 acid (eg, aspartic acid, glutamic acid); diaminomonocarboxylic acid (eg, lysine); amino acid having an aromatic nucleus (eg, p-hydroxyphenylglycine, phenylalanine, ant) Sulfonyl); aliphatic amino acid (e.g., sulfamic acid, cyclohexylsulfamic acid); and (poly) aminopolyacetic acid (e.g.,
Ethylenediaminetetraacetic acid, nitrilotriacetic acid, iminodiacetic acid, hydroxyethyliminodiacetic acid, hydroxyethylethylenediamineacetic acid, ethylenediaminediacetic acid, cycloethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, and glycoletherdiaminetetraacetic 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 the graining treatment of the aluminum support.

[Silver Halide Emulsion Layer] The silver halide emulsion layer generally contains gelatin as a binder. In tanning development, a relief image can be formed by hardening gelatin. Besides gelatin,
Tanning development can be performed 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. Gelatin may be used in combination with another hydrophilic polymer (eg, polyvinylpyrrolidone, starch, albumin, polyvinyl alcohol, gum arabic, hydroxyethyl cellulose). The amount of silver halide applied is
It is preferably 0.01 to 5 g / m ² , more preferably 0.03 to 1 g / m ² , and most preferably 0.05 to 0.3 g / m ² in terms of silver. The thickness of the silver halide emulsion layer is from 0.07 to 13
μm, more preferably 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.

The iridium compound or the 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 known surfactant 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.

[Optional Layer] The layer optionally provided in the lithographic printing plate precursor is preferably a layer containing a hydrophilic polymer as a binder, like the silver halide emulsion layer, and a layer containing gelatin as a binder. Is more preferable. A tanning developer can be added to an optional hydrophilic layer (eg, a hydrophilic protective layer).

For the purpose of lowering the tackiness of the front or back surface of the lithographic printing plate precursor and preventing adhesion when the lithographic printing plate precursors are stacked, a back layer containing a matting agent or an overcoat layer containing a matting agent is provided on the lithographic printing plate precursor. Can be provided. 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 coating amount of the matting agent is preferably in the range of 0.1 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. To the optional layer, the above-mentioned antifoggant, silver development accelerator for accelerating silver development, stabilizer and surfactant may be added.

FIG. 1 is a schematic sectional view of a lithographic printing original plate used in the present invention. As shown in FIG. 1, a silver halide gelatin emulsion layer (2) and a hydrophilic protective layer (3) are provided on a hydrophilic support (1). The silver halide gelatin emulsion layer (2) contains silver halide grains (21) and gelatin (22). The hydrophilic protective layer contains a tanning developer (31) and a hydrophilic polymer (32).

[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.

FIG. 2 is a schematic sectional view of a lithographic printing original plate during image exposure. As shown in FIG. 2, when the lithographic printing original plate is irradiated with light (L), 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).

[Tanning Development Step] Tanning development of the lithographic printing original plate is carried out using a developer. A tanning developer can be 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 from 5 to 40 ° C, more preferably from 20 to 35 ° C. The development time is preferably from 10 seconds to 10 minutes, and more preferably from 20 seconds to 3 minutes.

After the development, the image area may be treated with a solution containing a mercapto compound to enhance the lipophilicity of the image area.
-324866). Further, an acidic treatment or a fixing treatment may be performed. 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 developer is
It can be added to a tanning developer or a silver halide photosensitive material. The amount of the auxiliary developer is preferably 5 to 200 mol% of the amount of the tanning developer.

FIG. 3 is a schematic sectional view of a lithographic printing original plate in tanning development. As shown in FIG. 3, when the lithographic printing plate precursor after image exposure is immersed in a tanning developer (D), the silver halide particles in the exposed part are developed and the silver image (2) is developed.
1b) is formed. The oxidized product (quinone) of the tanning developer generated during the development is exposed to gelatin (22
a) is crosslinked. In contrast, there is no change in the unexposed portion of the gelatin (22).

[Elution Step] The lithographic printing plate precursor after the tanning development is immersed in hot water and rubbed on the surface to elute the uncured gelatin in the unexposed area, thereby forming a relief image of the cured gelatin. . 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. The formed relief image can be used as a lithographic printing plate by drying. As the post-treatment, heat treatment, light irradiation treatment, or chemical treatment may be performed.

FIG. 4 is a schematic cross-sectional view of a lithographic printing plate precursor during elution. As shown in FIG. 4, when the lithographic printing plate precursor after the tanning development is treated with the eluent (S), the hydrophilic protective layer and the unexposed portion of the silver halide gelatin emulsion layer are eluted. The silver halide gelatin emulsion layer (2a) in the exposed part is
The crosslinked gelatin (22a) remains on the hydrophilic support (1) to form a relief image. In this way, a lithographic printing plate can be made.

[0090]

[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.

[0092]

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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. 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

[0095]

Embedded image

[0096]

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"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.

<< Coating solution of silver halide gelatin emulsion layer >> 5g of the above silver halide emulsion 5g 10% by weight aqueous solution of gelatin 25g water 20g ───────────────────────────────────

"Formation of hydrophilic protective layer" The following coating solution was prepared, coated on a silver halide gelatin emulsion layer and dried to form a hydrophilic protective layer having a dry thickness of 0.3 µm. Thus, a lithographic printing original plate was produced.

塗布 Coating solution for hydrophilic protective layer───── １０ 10% by weight aqueous solution of polyvinyl alcohol (PVA-405, manufactured by Kuraray Co., Ltd.) 12.5 g methanol 30 g water 4 g tanning developer (I-2) 0.6 g ────

"Preparation of tanning developer" A tanning developer A and a B solution having the following compositions were prepared,
And used.

{Tanning Developer A Solution} ───────────────────────────── Pyrogallol 3 g Methol 3 g Citric acid 1 g Water 500 g ──────────── ────────────────────────

{Tanning developer B solution}カ リ ウ ム Potassium carbonate 200g Potassium iodide 1g Water 500g ──────────── ────────────────────────

(Image formation) The lithographic printing original plate was exposed to light having a light emission time of 10 ^-4 seconds by a xenon flash and a light of 670 nm separated by a sharp cut interference filter, and the energy on the surface of the photosensitive material became 2 μJ / cm ^2. A control wedge (manufactured by Fuji Photo Film Co., Ltd.) was brought into close contact with each other, and image exposure was performed. The lithographic printing plate precursor subjected to image exposure was immersed in the prepared tanning developer for 30 seconds. Then
The plate was washed with running water at 45 ° C. for 15 seconds. The surface of the lithographic printing original plate was lightly rubbed with a sponge to remove unexposed portions and dried, whereby a relief image having a uniform film surface on the aluminum support was obtained. This was used as a lithographic printing plate. The lithographic printing plate was wetted with water and rubbed with a PI 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 is converted to an offset printing machine (RYOBI32
(00CCD, manufactured by Ryobi Co., Ltd.), printing was performed, and the printing durability was examined. As a result, it was possible to print 10,000 sheets or more.

Examples 2 to 10 Instead of the tanning developer (I-2) added to the hydrophilic protective layer, tanning developers (I-4), (I-5), (I-11), (I-2
0), (I-27), (I-43), (I-73),
A lithographic printing original plate was prepared and evaluated in the same manner as in Example 1, except that (I-92) and (I-115) were used in the same amounts. The results are shown in Table 1.

[Comparative Example 1] Tanning developer (I-2)
Was prepared and evaluated in the same manner as in Example 1, except that was not added to the hydrophilic protective layer (only pyrogallol contained in the tanning developer A solution functions as a tanning developer). The results are shown in Table 1.

[0107]

[Table 1] Table 1-Lithographic printing plate hydrophilic protective layer Tanning developer Ink receptivity Printing durability ──────────────────────────────────── Example 1 ( I-2) Good 10,000 sheets or more Example 2 (I-4) Good 10,000 sheets or more Example 3 (I-5) Good 10,000 sheets or more Example 4 (I-11) Good 10,000 sheets or more Example 5 (I-20) Good 10,000 sheets or more Example 6 (I-27) Good 10,000 sheets or more Example 7 (I-43) Good 10,000 sheets or more Example 8 (I-73) Good 10,000 sheets or more Example 9 (I-92) Good 10,000 sheets or more Example 10 (I-115) Good 10,000 sheets or more Comparative Example 1 None Insufficient 50 sheets to lower the density ──────── ──────────────

[Example 11] "Formation of silver halide gelatin emulsion layer" The following coating solution was prepared, coated on the aluminum support used in Example 1, and dried. A 2 μm silver halide gelatin emulsion layer was provided. Thus, a lithographic printing original plate was produced.

{Coating Solution for Silver Halide Gelatin Emulsion Layer}銀 Silver halide emulsion used in Example 1 5 g 10% by weight aqueous solution of gelatin 25g water 20g ────────────────────────────────────

"Preparation of tanning developer" A tanning developer C and a D solution having the following composition were prepared,
And used.

{Tanning developer C solution} ５ 5% by weight methanol solution of tanning developer (I-1) 20 g Pyrogallol 3 g Methol 3 g Citric acid 1g water 500g ────────────────────────────────────

{Tanning developer D solution}カ リ ウ ム Potassium carbonate 200g Potassium iodide 1g Water 500g ──────────── ────────────────────────

(Image formation) The lithographic printing original plate was exposed to light having a light emission time of 10 ^-4 seconds by a xenon flash and a light of 670 nm was spectrally separated by a sharp cut interference filter, and the energy on the photosensitive material surface was 2 μJ / cm ^2. A control wedge (manufactured by Fuji Photo Film Co., Ltd.) was brought into close contact with each other, and image exposure was performed. The imagewise exposed lithographic printing plate precursor was immersed in a tanning developer for 30 seconds. Then, it was washed with running water at 45 ° C. for 15 seconds. Slightly rub the surface of the lithographic printing original plate with a sponge to remove the unexposed portions of the silver halide emulsion layer,
After drying, a relief image having a uniform film surface on the aluminum support was obtained. This was used as a lithographic printing plate. The lithographic printing plate was wetted with water and rubbed with a PI 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 is converted to an offset printing machine (R
YOBI 3200 CCD (Ryobi Co., Ltd.) was mounted and printed, and the printing durability was examined. As a result, it was possible to print 10,000 sheets or more.

Examples 12 to 18 In place of the tanning developer (I-1) added to the tanning developer, tanning developers (I-2), (I-19), (I-35),
(I-49), (I-59), (I-68) and (I-49)
-126) was used in Example 11 except that the same amounts were used.
In the same manner as in the above, a lithographic printing original plate was prepared and evaluated. The results are shown in Table 2.

[Comparative Example 2] Tanning developer (I-1)
Was prepared and evaluated in the same manner as in Example 11, except that was not added to the tanning developer (only pyrogallol contained in the tanning developer C functions as a tanning developer). The results are shown in Table 2.

[0116]

[Table 2] Table 2 ──────────────────────────────────── Tanning developer Tanning developer Ink acceptability Printing durability ──────────────────────────────────── Example 11 Pyrogallol + (I-1) Good 10,000 sheets or more Example 12 Pyrogallol + (I-2) Good 10,000 sheets or more Example 13 Pyrogallol + (I-19) Good 10,000 sheets or more Example 14 Pyrogallol + (I-35) Good 10,000 sheets or more Example 15 Pyrogallol + (I-49) Good 10,000 sheets or more Example 16 Pyrogallol + (I-59) Good 10,000 sheets or more Example 17 Pyrogallol + (I-68) Good 10,000 sheets or more Example 18 Pyrogallol + (I-124) Good 10,000 sheets or more Comparative Example 2 Pyrogallol Lack 5 hundred at a concentration decrease ────────────────────────────────────

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a lithographic printing original plate used in the present invention.

FIG. 2 is a schematic cross-sectional view of a lithographic printing original plate during image exposure.

FIG. 3 is a schematic cross-sectional view of a lithographic printing original plate in tanning development.

FIG. 4 is a schematic cross-sectional view of a lithographic printing plate precursor during elution.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydrophilic support 2 Lithographic printing material layer 2a Lithographic printing material layer of an exposed part 21 Silver halide particle 21a Latent image of silver halide particle 21b Silver image 22 Gelatin 22a Crosslinked gelatin 3 Hydrophilic protective layer 31 Tanning developer 32 Hydrophilic polymer D Tanning developer L Light S Eluent

Claims (3)

[Claims] 1. A step of imagewise exposing a lithographic printing plate precursor having a silver halide gelatin emulsion layer on a hydrophilic support, wherein the lithographic printing plate precursor is subjected to tanning development using a developing agent represented by the following formula (I). The step of hardening the gelatin in the exposed area, and the step of eluting the unhardened gelatin in the unexposed area to form a relief image of the hardened gelatin in this order are performed to make a lithographic printing plate. Plate making method of lithographic printing plate: Wherein n is 1 or 2; and R is an aliphatic group having 5 to 40 carbon atoms, and 7 to 4 carbon atoms.
0 aromatic groups, aliphatic acyl groups having 5 to 40 carbon atoms, aromatic acyl groups having 7 to 40 carbon atoms, aliphatic oxycarbonyl groups having 5 to 40 carbon atoms, and carbon atoms having 5 to 40 carbon atoms. An aromatic oxycarbonyl group having 7 to 40 carbon atoms, an aliphatic acyloxy group having 5 to 40 carbon atoms, an aromatic acyloxy group having 7 to 40 carbon atoms, and 5 carbon atoms;
To 40 aliphatic substituted carbamoyl groups or aromatic substituted carbamoyl groups having 7 to 40 carbon atoms]. 2. The method according to claim 1, wherein the developer is represented by the following formula (Ia), (Ib),
2. The method for making a lithographic printing plate according to claim 1, which is represented by (Ic) or (Id). [In the formula, R is an aliphatic group having 5 to 40 carbon atoms, an aromatic group having 7 to 40 carbon atoms, an aliphatic acyl group having 5 to 40 carbon atoms, and 7 to 40 carbon atoms. 40 aromatic acyl groups, aliphatic oxycarbonyl groups having 5 to 40 carbon atoms, aromatic oxycarbonyl groups having 7 to 40 carbon atoms, aliphatic acyloxy groups having 5 to 40 carbon atoms, carbon atoms An aromatic acyloxy group having 7 to 40 carbon atoms, an aliphatic substituted carbamoyl group having 5 to 40 carbon atoms, or an aromatic substituted carbamoyl group having 7 to 40 carbon atoms]. 3. A lithographic printing plate having a relief image of hardened gelatin on a hydrophilic support, wherein the hardened gelatin is formed by a hardening reaction of gelatin by an oxidized form of a developing agent represented by the following formula (I). Lithographic printing plate characterized by the following: Wherein n is 1 or 2; and R is an aliphatic group having 5 to 40 carbon atoms, and 7 to 4 carbon atoms.
0 aromatic groups, aliphatic acyl groups having 5 to 40 carbon atoms, aromatic acyl groups having 7 to 40 carbon atoms, aliphatic oxycarbonyl groups having 5 to 40 carbon atoms, and carbon atoms having 5 to 40 carbon atoms. An aromatic oxycarbonyl group having 7 to 40 carbon atoms, an aliphatic acyloxy group having 5 to 40 carbon atoms, an aromatic acyloxy group having 7 to 40 carbon atoms, and 5 carbon atoms;
To 40 aliphatic substituted carbamoyl groups or aromatic substituted carbamoyl groups having 7 to 40 carbon atoms].