JPH06324477A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To substantially obviate the generation of stains in shadow parts on a printing machine and to make it possible to obtain stable printed matter having high quality by specifying a relation between a base subjected to surface roughening and the surface roughness after development of a photosensitive layer formed on the surface thereof. CONSTITUTION:The surface roughness Ra of the base surface of the photosensitive planographic printing plate formed by providing the surface of the base subjected to the surface roughening with the photosensitive layer and the difference DELTARa between the surface roughness Ra of this base surface and the surface roughness TRa of the photosensitive layer after development are so set as to satisfy equation, where units are both mum. An aluminum sheet or the like is more preferable as this base. The aluminum sheet having about 0.1 to 0.6mm thickness is subjected to a sand dressing treatment by an electrochemical sand dressing method, etc., and is then etched by an alkali, etc. The conditions for application of the photosensitive layer are controlled according to the surface roughness of the base surface subjected to surface roughening. The base surface is respectively so treated that the surface roughness Ra of the base surface attains 0.2 to 1.5mum (10muR stylus) and is further preferably 0.4 to 1.2mum.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a photosensitive lithographic printing plate (P
The present invention relates to a photosensitive lithographic printing plate which provides a lithographic printing plate in which a halftone portion (shadow portion) of an image area is hard to be stained.

[0002]

2. Description of the Related Art In recent years, demands for resource saving, labor saving, and speeding up have been further increased in the printing industry, and an "easy-to-print printing plate" capable of meeting those demands has been demanded. For this purpose, it is important to obtain beautiful printed matter without strict control of printing conditions, especially dampening water and ink. One of the factors for achieving this is that the printing plate is excellent in stain resistance, particularly in the halftone portion of the image area.

Conventionally, an aluminum plate has been widely used as a support for a lithographic printing plate, but the surface of the support is provided in order to improve the adhesion between the support and the photosensitive layer and to impart water retention to the non-image area. A so-called graining treatment for roughening is performed. Specific means of this graining treatment method are mechanical sand such as sand blast, ball grain, wire grain, brush grain with nylon brush and abrasive / water slurry, and honing grain with abrasive / water slurry sprayed on the surface at high pressure. There is a graining method, and there is a chemical graining method in which the surface is roughened with an etching agent composed of an alkali, an acid or a mixture thereof. Also, British Patent No. 896,563, JP-A-53-67507, and JP-A-54-14.
6234 and Japanese Patent Publication No. 48-28123, an electrochemical graining method, for example, JP-A-5-
A method combining a mechanical graining method and an electrochemical graining method described in JP-A-3-123204, a mechanical graining method described in JP-A-56-55261 and a mineral acid A method that combines a chemical graining method with a saturated aqueous solution of an aluminum salt is also known.

In order to characterize the shape of the surface subjected to various surface-roughening treatments as described above, several prior art documents have been known, for example, US Pat. No. 4,301,22.
No. 9 defines the cumulative frequency distribution of the pit diameter and centerline average roughness, US Pat. No. 3,861,917 defines the depth of the rough surface, and Canadian Patent No. 955,449. The specification defines the height and diameter of the peaks of the rough surface. Also,
German Patent No. 1,813,443 defines the height difference of a rough surface, and JP-A-55-132294 defines an average depth (a roughness average value by a stylus type surface roughness meter). ing.

However, in these prior arts, although various parameters are specified, both the printing durability and the stain resistance when used as a printing plate are satisfied, and particularly, the stain in the halftone portion of the image area is satisfied. No one has achieved excellent performance in terms of difficulty. Also, the pit diameter and pit
Japanese Patent Laid-Open No. 167196/58 is a known document that defines the direction dependence of roughness, average roughness, and the like.
It defines the pit diameter, its direction dependence, centerline average roughness, its direction dependence, etc.The material with a photosensitive layer provided on a support having this rough surface shape is used to screen originals with continuous gradation. It has been shown to have the effect of enabling faithful tone reproduction in applications where a printing plate is created without taking a picture, but this also shows stains in the halftone part of the image area when used as a printing plate. There is no disclosure or suggestion of the difficulties and parameters.

[0006]

Therefore, in the above-mentioned known technique, it is insufficient in terms of the stain resistance of the halftone portion of the image area, and it is necessary to find a photosensitive lithographic printing plate which can satisfy this performance. Is the object of the present invention.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that the surface roughness of a roughened support surface and a photosensitive layer formed on the support surface. The inventors have found that the above object can be achieved by controlling the surface roughness of the photosensitive layer surface after development of the coated photosensitive lithographic printing plate, and completed the present invention. The present invention provides a photosensitive lithographic printing plate in which a photosensitive layer is provided on the surface of a roughened support, and the surface roughness (R
a) (μm) and the difference (ΔRa) (μm) between Ra and the surface roughness (TRa) (μm) of the surface of the photosensitive layer after development satisfy the following relational expression: It is a lithographic printing plate. ΔRa ≦ 0.6 × Ra−0.05 (1)

The photosensitive lithographic printing plate of the present invention will be described in detail below. The support that can be used in the present invention is preferably a support made of metal, plastic, paper alone or a composite (aluminum, steel, galvanized iron, tin plate, stainless steel, etc.). The aluminum plate used in the present invention is selected from a pure aluminum plate, an alloy plate containing aluminum as a main component and a slight amount of a foreign element, or a plastic film laminated or vapor-deposited with aluminum.
The different elements contained in the aluminum alloy include silicon,
Examples include iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium. The content of foreign elements in the alloy is 10% by weight or less. Aluminum suitable for the present invention is pure aluminum, but completely pure aluminum is difficult to produce due to refining technology, and thus may contain slightly different elements. Thus, the aluminum plate applied to the present invention, the composition is not specified, conventionally known publicly known material, for example JIS A
1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. can be appropriately used. The aluminum plate used in the present invention has a thickness of about 0.1 mm to 0.6 mm.

The graining method in the present invention is an electrochemical graining method in which a grain is electrochemically grained in a hydrochloric acid or nitric acid electrolyte solution, a wire brush grain method of scratching an aluminum surface with a metal wire, a polishing ball and an abrasive. A mechanical graining method such as a ball graining method for graining the aluminum surface or a brush graining method for graining the surface with a nylon brush and an abrasive can be used, and any of the above graining methods can be used alone or in combination. You can also

The aluminum thus grained is chemically etched with acid or alkali. When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous in industrially applying the present invention, but it can be improved by using an alkali as the etching agent. Alkali agents preferably used in the present invention include caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, etc., and the preferred ranges of concentration and temperature are 1 to 50, respectively. %, 20 to 100 ° C., and the condition that the amount of dissolved Al is 5 to 20 g / m ³ is preferable. After etching, pickling is performed to remove stains (smut) remaining on the surface. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid or the like is used. Particularly, it is preferably used for the smut removing treatment after the electrochemical graining treatment.
50 to 90 ° C. as described in 12739 publication
Of 15 to 65 wt% of sulfuric acid at the above temperature and the method of alkali etching described in JP-B-48-28123.

The aluminum alloy plate treated as described above can be used as a support for a lithographic printing plate, but may be further subjected to a treatment such as anodizing treatment or chemical conversion treatment, if necessary. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, when a direct current or an alternating current is applied to aluminum in an aqueous solution or a non-aqueous solution by combining sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., or a combination of two or more thereof, the surface of the aluminum support It is possible to form an anodized film on. The conditions of anodic oxidation cannot be unconditionally determined because they vary depending on the electrolytic solution used, but generally the concentration of the electrolytic solution is 1-80.
%, Liquid temperature 5 to 70 ° C., current density 0.5 to 60 amps / dm
² , a voltage of 1 to 100 V and an electrolysis time of 10 to 100 seconds are suitable. Among these anodic oxide film treatments, a method of anodizing at high current density in sulfuric acid, which is used in the invention described in British Patent No. 1,412,768, and US Pat. The method of anodic oxidation using phosphoric acid as an electrolytic bath described in the specification of 511,661 is preferable.

After the anodizing treatment, the aluminum surface is optionally subjected to a hydrophilic treatment. As the hydrophilic treatment used in the present invention, US Patent No. 2,714,066,
There are alkali metal silicate (eg aqueous sodium silicate) processes such as those disclosed in Nos. 3,181,461, 3,280,734 and 3,902,734. In this method, the support is immersed or electrolyzed in an aqueous sodium silicate solution. In addition, Japanese Patent Publication Sho 36-22
For example, the method of treatment with potassium fluorozirconate disclosed in Japanese Patent Application No. 063 and polyvinyl phosphonic acid as disclosed in US Pat. Nos. 3,276,868, 4,153,461 and 4,689,272 may be used. It is also preferable that after the graining treatment and the anodic oxidation, the sealing treatment is performed. Such sealing treatment is performed by immersion in hot water and a hot aqueous solution containing an inorganic salt or an organic salt, a steam bath, or the like.

If necessary, an organic undercoat layer is provided on the aluminum plate before coating the photosensitive layer. Examples of the organic compound used in this organic undercoat layer include phosphonic acids having an amino group such as carboxymethyl cellulose, dextrin, gum arabic, and 2-aminoethylphosphonic acid, phenylphosphonic acid which may have a substituent, and naphthyl. Organic phosphonic acids such as phosphonic acid, alkylphosphonic acid, glycerophosphonic acid, methylenediphosphonic acid and ethylenediphosphonic acid, phenylphosphoric acid which may have a substituent, naphthylphosphoric acid, alkylphosphoric acid and glycerophosphoric acid Phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, organic phosphinic acids such as alkylphosphinic acid and glycerophosphinic acid, amino acids such as glycine and β-alanine, and triethanolamine hydrochloride The hydroxy Although selected from such as hydrochloric acid salt of an amine having a group,
You may use it in mixture of 2 or more types.

This organic undercoat layer can be provided by the following method. That is, water or a solvent in which the above organic compound is dissolved in an organic solvent such as methanol, ethanol, methyl ethyl ketone or a mixed solvent thereof is applied on an aluminum plate and dried to provide a method, and water or methanol, ethanol, methyl ethyl ketone, etc. In a solution prepared by dissolving the above organic compound in the organic solvent or a mixed solvent thereof, the aluminum plate is immersed to adsorb the above organic compound, and then washed with water or the like and dried to form an organic undercoat layer. Is the way. In the former method, a solution having a concentration of 0.005 to 10% by weight of the above organic compound can be applied by various methods. For example, any method such as bar coater coating, spin coating, spray coating, or curtain coating may be used. Also, in the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 20 to 90 ° C, preferably 25.
~ 50 ° C, and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The pH of the solution used for this is adjusted with basic substances such as ammonia, triethylamine and potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid.
It can also be used in the range of pH 1-12. Further, a yellow dye may be added to improve the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is 2
~ 200 mg / m ² is suitable, preferably 5-100 mg /
m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same applies when the amount is larger than 200 mg / m ² .

A photosensitive layer made of a known photosensitive composition is provided on the thus obtained aluminum plate having a hydrophilic surface to obtain a photosensitive lithographic printing plate. The characteristic of the present invention is that the coating conditions of the photosensitive layer (for example, the solid content concentration and viscosity of the coating liquid of the photosensitive layer, the coating speed, the thickness of the photosensitive layer, etc.)
Is controlled according to the surface roughness (Ra) of the roughened surface of the support, whereby a photosensitive lithographic printing plate excellent in stain resistance of the shadow portion of the image area can be obtained. By changing the surface roughness of the roughened support surface and changing the coating conditions of the photosensitive layer, the surface roughness (Ra) of the support surface (Ra) (μm) and Ra can be used to determine the photosensitive layer surface roughness (T
As a result of examining the relation of ΔRa (μm) obtained by subtracting Ra) (μm), Ra and ΔRa satisfy the relation of the above formula (1) in order to obtain excellent stain resistance of the shadow portion of the image portion. Has come to discover that there is a need. In addition, Ra is preferably treated so as to be 0.2 to 1.5 μ (stylus 10 μR), and more preferably 0.1.
It is 4 to 1.2 μm. In the specification of the present application, the surface roughness of the photosensitive layer means the surface roughness after development, and does not include the influence of the matte layer provided on the surface of the photosensitive layer and the influence of the surface after gumming. In a particularly preferred embodiment of the present invention, Ra and ΔRa are adjusted so as to satisfy the relationship of the following general formula (2). ΔRa ≦ 0.5 × Ra-0.05 (2)

The photosensitive composition used in the photosensitive layer of the present invention mainly comprises a positive type composition containing an o-quinonediazide compound as a main component, a diazonium salt, an alkali-soluble diazonium salt, and an unsaturated double bond-containing monomer. A negative type compound having a photopolymerizable compound as a component and a photocrosslinkable compound containing a cinnamic acid or a dimethylmaleimide group as a photosensitive material is used. In addition, Japanese Examined Patent Publication Nos. 37-17172 and 38-6
961, JP-A-56-107246, 60-25.
No. 4142, Japanese Patent Publication Nos. 59-36259, 59-25.
217, JP-A-56-146145 and JP-A-62-19.
No. 4257, No. 57-147656, No. 58-100.
The electrophotographic photosensitive layers described in 862 and 57-161863 can also be used. Among the above photosensitive materials, examples of the photopolymerizable compound containing an unsaturated double bond-containing monomer as a main component include U.S. Pat. Nos. 2,760,863 and 3,060,02.
A composition comprising a photopolymerization initiator and an addition-polymerizable unsaturated compound having two or more terminal ethylene groups described in Japanese Patent No. 3 and JP-A-59-53836 can be used. Further, as a negative type photosensitive material containing a photocrosslinkable compound containing a dimethylmaleimide group, for example, JP-A-52-98 is disclosed.
No. 8, European Patent No. 0410654, JP-A-3-2888.
Examples thereof include the photosensitive materials described in JP-A No. 53-53 and JP-A-4-25845.

Among these, as the o-naphthoquinonediazide compound used as a positive photosensitive composition, 1,2-diazonaphthoquinonesulfonic acid and pyrogallol-acetone resin described in JP-B-43-28403 are used. Esters are preferred. Other suitable orthoquinonediazide compounds include, for example, U.S. Pat.
There are esters of 1,2-diazonaphthoquinone-5-sulfonic acid and phenol-formaldehyde resin described in JP-A No. 120 and No. 3,188,210, and JP-A-2-96163 and JP-A-2-96165. There is an ester of 1,2-diazonaphthoquinone-1-sulfonic acid and a phenol-formaldehyde resin described in JP-A-2-967671 and JP-A-2-96761. Other useful o-naphthoquinonediazide compounds include:
Those known in numerous patents can be mentioned. For example, JP-A Nos. 47-5303, 48-63802 and 48
-63803, 48-96575, 49-38.
No. 701, No. 48-13854, Japanese Patent Publication No. 37-180
No. 15, No. 41-11222, No. 45-9610,
No. 49-17481, U.S. Pat. No. 2,797,213,
No. 3,453,400, No. 3,544,323, No. 3,573,917
No. 3,674,495, No. 3,785,825, British Patent No.
1,227,602, 1,251,345, 1,267,005,
1,329,888, 1,330,932, German Patent 854,
Mention may be made of those described in each specification such as No. 890.

A particularly preferred o-naphthoquinonediazide compound is a compound obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid. Specific examples of such compounds are described in JP-A Nos. 51-139402 and 58-15094.
No. 8, No. 58-203434, No. 59-165053.
No. 60, No. 12-14445, No. 60-134235.
Issue No. 60-163043, Issue No. 61-118744
No. 6, No. 62-10645, No. 62-10646, No. 62-153950, No. 62-178562, No. 6
4-76047, U.S. Pat. Nos. 3,102,809 and 3,12.
No. 6,281, No. 3,130,047, No. 3,148,983, No.
Examples thereof include those described in respective publications or specifications such as 3,184,310, 3,188,210, and 4,639,406. When synthesizing these o-naphthoquinone diacid compounds, it is preferable to react 0.2-1.2 equivalents of 1,2-diazonaphthoquinone sulfonic acid chloride with respect to the hydroxyl group of the polyhydroxy compound.
It is more preferable to react 3 to 1.0 equivalent. 1,2-
As the cyazonaphthoquinone sulfonic acid chloride, 1,
2-diazonaphthoquinone-5-sulfonic acid chloride or 1,2-diazonaphthoquinone-4-sulfonic acid chloride can be used. The obtained o-naphthoquinonediazide compound is a mixture of 1,2-diazonaphthoquinonesulfonic acid ester groups having different positions and introduction amounts, but all of the hydroxyl groups are 1,2.
The proportion of the diazonaphthoquinonesulfonic acid esterified compound in the mixture (content of the completely esterified compound) is preferably 5 mol% or more, more preferably 20 to 99 mol%. is there. The amount of these positive-working photosensitive compounds (including the above-mentioned combinations) in the photosensitive composition is suitably 10 to 50% by weight, more preferably 15 to 40% by weight.

The o-quinonediazide compound alone can form the photosensitive layer, but it is preferable to use a resin soluble in alkaline water together as a binder. As such a resin soluble in alkaline water, there are novolac type resins such as phenol formaldehyde resin, o-, m- and p-cresol formaldehyde resin, m / p-mixed cresol formaldehyde resin, phenol / cresol ( o-, m-, p-, m /
mixed formaldehyde resin and the like may be used. Further, phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, and an acrylic resin containing a phenolic hydroxyl group as disclosed in JP-A-51-34711 can also be used. Other suitable binders include copolymers having the following monomers (1) to (13) as constituent units and having a molecular weight of usually 10,000 to 200,000. (1) Acrylamides, methacrylamides, acrylates, methacrylates and hydroxystyrenes having aromatic hydroxyl groups, such as N- (4
-Hydroxyphenyl) acrylamide or N- (4
-Hydroxyphenyl) methacrylamide, o-, m-
And p-hydroxystyrene, o-, m- and p-
Hydroxyphenyl acrylate or methacrylate, (2) acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group, for example, 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, (3) acrylic acid, methacrylic acid, maleic anhydride. Unsaturated carboxylic acids such as, methaconic acid,

(4) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, phenyl acrylate, benzyl acrylate, acrylate-2 -(Substituted) acrylic acid esters such as -chloroethyl, 4-hydroxybutyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate, (5) methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, octyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, 4-hydroxybutyl methacrylate, (Substituted) methacrylic acid esters such as glycidyl methacrylate and N-dimethylaminoethyl methacrylate, (6) acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N-ethyl acrylamide, N-ethyl methacrylamide, N- Hexyl acrylamide, N
-Hexyl methacrylamide, N-cyclohexyl acrylamide, N-cyclohexyl methacrylamide, N
-Hydroxyethyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N
-Phenylmethacrylamide, N-benzylacrylamide, N-benzylmethacrylamide, N-nitrophenylacrylamide, N-nitrophenylmethacrylamide, N-ethyl-N-phenylacrylamide and N-ethyl-N-phenylmethacrylamide. Or methacrylamide,

(7) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and phenyl vinyl ether, (8) vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate, (9) styrenes such as styrene, methylstyrene and chloromethylstyrene, ( 1
0) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone, (11) olefins such as ethylene, propylene, isobutylene, butadiene and isoprene, (1)
2) N-vinylpyrrolidone, N-vinylcarbazole,
(13) N- (o-aminosulfonylphenyl) acrylamide, N- (m-aminosulfonylphenyl) acrylamide, N- (p-aminosulfonylphenyl) acrylamide, N-, 4-vinylpyridine, acrylonitrile, methacrylonitrile, etc. [1- (3-Aminosulfonyl) naphthyl] acrylamide, acrylamides such as N- (2-aminosulfonylethyl) acrylamide, N- (o-aminosulfonylphenyl) methacrylamide, N- (m-aminosulfonylphenyl) methacryl Methacrylamides such as amide, N- (p-aminosulfonylphenyl) methacrylamide, N- [1- (3-aminosulfonyl) naphthyl] methacrylamide, N- (2-aminosulfonylethyl) methacrylamide, and o Aminosulfonylphenyl acrylate, m- aminosulfonylphenyl acrylate,
p-aminosulfonylphenyl acrylate, 1- (3
-Aminosulfonylphenylnaphthyl) acrylates and other unsaturated sulfonamides such as acrylic acid esters, o-aminosulfonylphenyl methacrylate, m
-Unsaturated sulfonamides such as methacrylic acid esters such as aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, 1- (3-aminosulfonylphenylnaphthyl) methacrylate.

Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate, glycidyl methacrylate, etc., but is not limited thereto. The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable acid value of the copolymer is 0.
-10 meq / g, more preferably 0.2-5.0 meq / g. The preferred molecular weight of the above copolymer is 10,000 to 100,000. Further, polyvinyl butyral resin, polyurethane resin, polyamide resin and epoxy resin may be added to the above-mentioned copolymer, if necessary. Such alkali-soluble polymer compounds may be used alone or in combination of two or more, and 80% by weight of the total photosensitive composition
It is used in the following addition amounts. Further, U.S. Pat.
As described in No. 9, it is not possible to use a condensate of phenol and formaldehyde, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, having a C3-8 alkyl group as a substituent. It is preferable for improving the oil sensitivity. Cyclic acid anhydrides, phenols, and organic acids are preferably added to the photosensitive composition of the present invention in order to enhance sensitivity.

Cyclic acid anhydrides include US Pat. No. 4,115,12
No. 8 phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-
Endooxy-Δ ⁴ -tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic acid free, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride,
Pyromellitic anhydride or the like can be used. Examples of phenols include bisphenol A, p-nitrophenol, p
-Ethoxyphenol, 2,4,4'-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ',
4 "-trihydroxy-triphenylmethane, 4,
4 ', 3 ", 4"-tetrahydroxy-3,5,3',
5'-tetramethyltriphenylmethane and the like can be mentioned. Further, as organic acids, JP-A-60-88942 is used.
No. 2, JP-A-2-96755 and the like, sulfonic acids, sulfinic acids, alkylsulfates,
There are phosphonic acids, phosphoric acid esters, carboxylic acids, and the like. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid,
Ethyl sulfuric acid, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 1,4 −
Examples thereof include cyclohexene-2,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid and ascorbic acid. The ratio of the above cyclic acid anhydrides, phenols and organic acids in the photosensitive composition is 0.05 to 1
It is preferably 5% by weight, more preferably 0.1 to 5% by weight.

Further, in the photosensitive composition of the present invention, in order to broaden the stability of processing (so-called development latitude) with respect to developing conditions, a nonionic interface as described in JP-A-62-251740 is used. Activators, amphoteric surfactants such as those described in JP-A-59-121044 and JP-A-4-13149 can be added. Specific examples of the nonionic surfactant include:
Sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene sorbitan monooleate,
Examples thereof include polyoxyethylene nonylphenyl ether. Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N.
-Tetradecyl-N, N-betaine type (for example, trade name Amogen K, manufactured by Daiichi Kogyo Co., Ltd.) and alkyl imidazoline series (for example, trade name Levon 15, manufactured by Sanyo Kasei Co., Ltd.) and the like. The proportion of the nonionic surfactant and the amphoteric surfactant in the photosensitive composition is preferably 0.05 to 15% by weight, more preferably 0.05% by weight.
It is 1 to 5% by weight.

In the photosensitive composition of the present invention, a printing-out agent for obtaining a visible image immediately after exposure and a dye or pigment as an image coloring agent can be added. Typical examples of the printout agent include a combination of a compound that releases an acid upon exposure (photoacid releasing agent) and an organic dye capable of forming a salt. Specifically, JP-A-50-3620
No. 9 and 53-8128
-A combination of naphthoquinone diazide-4-sulfonic acid halogenide and a salt-forming organic dye, and JP-A-53-36223.
No. 54, No. 54-74728, No. 60-3626, No. 6
Examples include combinations of trihalomethyl compounds and salt-forming organic dyes described in JP-A Nos. 1-143748, 61-151644 and 63-58440. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent stability over time and give a clear printout image.

As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS,
Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (above, manufactured by Orient Chemical Industry Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine. B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI5201)
5) etc. can be mentioned. In addition, JP-A-62-2
The dyes described in Japanese Patent No. 93247 are particularly preferable.

The photosensitive composition is dissolved in a solvent that dissolves each of the above components and applied onto the aluminum plate of the support.
The solvent used here is, for example, JP-A-62-2517.
Organic solvents as described in JP-A-39 are used alone or in combination. The photosensitive composition is dissolved and dispersed at a solid content concentration of 2 to 50% by weight and applied on a support.
To be dried. The coating amount of the layer of the photosensitive composition (photosensitive layer) coated on the support varies depending on the use, but generally, the weight after drying is preferably 0.3 to 4.0 g / m ^2. .
The smaller the coating amount, the smaller the exposure amount for obtaining an image, but the film strength decreases. As the coating amount increases, the exposure amount is required but the photosensitive film becomes stronger. For example, when used as a printing plate, a printing plate having a high printable number (high printing durability) can be obtained. In the photosensitive composition, a surfactant for improving the coating surface quality, for example, JP-A-62-62
A fluorine-based surfactant as described in JP-A-170950 can be added. The preferable addition amount is 0.001 to 1.0% by weight, and more preferably 0.005 to 0.5% by weight of the total photosensitive composition.

Next, the negative PS plate photosensitive composition includes those having a photosensitive layer containing a photosensitive diazo compound, a photopolymerizable photosensitive layer, a photocrosslinkable photosensitive layer, and the like.
Of these, the photocurable photosensitive copying material comprising a photosensitive diazo compound will be described in detail with reference to examples. As the photosensitive diazo compound, a diazo resin obtained by condensing an aromatic diazonium salt and a reactive carbonyl group-containing organic condensing agent, particularly aldehydes such as formaldehyde and acetaldehyde or acetals in an acidic medium is preferably used. The most typical one is a condensate of P-diazodiphenylamine and formaldehyde. Methods for synthesizing these diazo resins are described, for example, in U.S. Patent No. 2,678,498,
No. 3,050,502, No. 3,311,605 and No. 3,277,
No. 074. Further, as the photosensitive diazo compound, a co-condensation diazo compound of an aromatic diazonium salt described in JP-B-49-48,001 and a substituted aromatic compound containing no diazonium group is preferably used. A co-condensed diazo compound with an aromatic compound substituted with an alkali-soluble group such as a hydroxyl group is preferable. Furthermore, JP-A-4-18559, JP-A-4-190361 and JP-A-4-172353.
A photosensitive diazo compound obtained by condensing an aromatic diazonium salt with a reactive carbonyl compound having an alkali-soluble group as described in JP-A No. 1993-154 is also preferably used. There are diazo resins using inorganic anions such as mineral acids such as hydrochloric acid, hydrobromic acid, sulfuric acid and phosphoric acid or double salts with zinc chloride as counter anions of these diazonium salts, but they are substantially water-insoluble and organic. Solvent-soluble diazo resins are particularly preferred. Such preferred diazo resins are described in detail in JP-B-47-1167 and U.S. Pat. No. 3,300,309.

Further, JP-A-54-98613 and 56-56.
A diazo resin having a counter anion of halogenated Lewis acid such as tetrafluoroboric acid and hexafluorophosphoric acid and perhalogen acid such as perchloric acid and periodic acid as described in JP-A-121031 is preferably used. To be
Also, JP-A-58-209733 and JP-A-62-1757.
The diazo resins having a long-chain alkyl group-containing sulfonic acid as a counter anion, which are described in JP-A Nos. 31 and 63-262643, are also preferably used. The photosensitive diazo compound is contained in the photosensitive layer in an amount of 5 to 50% by weight, preferably 8 to 20% by weight. The photosensitive diazo compound is preferably used in combination with a lipophilic polymer compound soluble or swellable in alkaline water as a binder. Examples of such lipophilic polymer compounds include the same compounds (1) to (1) as those used in the positive-type photosensitive composition described above.
A copolymer having a molecular weight of 10,000 to 200,000, which has the monomer shown in (13) as its constitutional unit, can be mentioned. Further, the monomers shown in (14) and (15) below are used as constitutional units. Polymerized polymer compounds can also be used. (14) Maleimide, N-acryloylacrylamide, N-acetylacrylamide, N-propionylacrylamide, N- (p-chlorobenzoyl) acrylamide, N-acetylacrylamide, N-acryloylmethacrylamide, N-acetylmethacrylamide,
Unsaturated imides such as N-propionyl methacrylamide, N- (p-chlorobenzoyl) methacrylamide,
(15) N- [2- (acryloyloxy) -ethyl]
-2,3-Dimethylmaleimide, N- [6- (methacryloyloxy) -hexyl] -2,3-dimethylmaleimide, unsaturated monomers having a crosslinkable group in the side chain such as vinylcinnamate.

Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate, glycidyl methacrylate, etc., but is not limited thereto. The above copolymer preferably contains the unsaturated carboxylic acid listed in (3), and the preferable acid value of the copolymer is 0.
-10 meq / g, more preferably 0.2-5.0 meq / g. The preferred molecular weight of the above copolymer is 10,000 to 100,000. Further, polyvinyl butyral resin, polyurethane resin, polyamide resin and epoxy resin may be added to the above-mentioned copolymer, if necessary. It is also possible to use a novolac type resin, a phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, or an alkali-soluble resin containing a phenolic hydroxyl group as disclosed in JP-A-51-43711. it can. Such alkali-soluble polymer compounds can be used alone or in combination of two or more, and usually 40 to 95% by weight in the solid content of the whole photosensitive composition.
It is contained in the range of.

In the photosensitive composition, an oil-sensitizing agent for improving the oil-sensitivity of an image (for example, a half ester of a styrene-maleic anhydride copolymer described in JP-A No. 55-527) with an alcohol is used. Compound, novolac resin, p-
50% fatty acid ester of hydroxystyrene, etc.) is added. Furthermore, a plasticizer for imparting flexibility and abrasion resistance to the coating film is added. For example, butylphthalyl,
Polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate,
Examples include dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid oligomers and polymers, of which tricresyl phosphate is particularly preferred. Further, in the photosensitive composition, in order to spread stability over time, for example, phosphoric acid, phosphorous acid, citric acid, oxalic acid, dipicolinic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfosalicylic acid, 4-methoxy- 2-Hydroxybenzophenone-5-sulfonic acid, tartaric acid and the like are added.

Further, in the photosensitive composition, a printing-out agent for obtaining a visible image immediately after exposure and a dye such as a dye or a pigment as an image colorant can be added. As the dye, those that change color tone by reacting with free radicals or acids are preferably used. For example, Victoria Pure Blue BOH (Hodogaya Chemical), Oil Yellow # 1
01, oil yellow # 103, oil pink # 31
2, oil red, oil green BG, oil blue BOS, oil blue # 603, oil black BY,
Oil Black BS, Oil Black T-505 (above, manufactured by Orient Chemical Industry Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), Crystal Violet (CI42555), Methyl Violet (CI425)
35), ethyl violet, rhodamine B (CI14
5170B), malachite green (CI4200
0), methylene blue (CI52015), brilliant blue, methyl green, erythricin B, basic fuchsin, m-cresol purple, auramine, 4
-P-diethylaminophenyliminaphthoquinone, cyano-p-diethylaminophenylacetanilide and other triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based or anthraquinone-based dyes are colored or colorless or An example of changing to different color tones is given.

On the other hand, as a discoloring agent that changes from colorless to colored, leuco dyes and, for example, triphenylamine, diphenylamine, o-chloroaniline, 1, 2,
3-triphenylguanidine, naphthylamine, diaminodiphenylmethane, p, p'-bis-dimethylaminodiphenylamine, 1,2-dianilinoethylene, p,
p ', p "-tris-dimethylaminotriphenylmethane, p, p'-bis-dimethylaminodiphenylmethylimine, p, p', p" -triamino-o-methyltriphenylmethane, p, p'-bis -Dimethylaminodiphenyl-4-anilinonaphthylmethane, p, p ', p "
-Primary or secondary arylamine dyes represented by triaminotriphenylmethane. Particularly preferred are triphenylmethane dyes and diphenylmethane dyes, more preferably triphenylmethane dyes, and particularly Victoria Pure Blue BOH. The dye is usually contained in the photosensitive composition in an amount of about 0.5 to 10% by weight, more preferably about 1 to 5% by weight.

Cyclic acid anhydrides, phenols, organic acids and higher alcohols can be added to the photosensitive composition in order to enhance developability. The photosensitive composition is
It is dissolved in a solvent that dissolves each of the above components and coated on an aluminum plate of a support. As the solvent used here, the organic solvents described in JP-A-62-251739 are used alone or in combination. The photosensitive composition is dissolved and dispersed at a solid content concentration of 2 to 50% by weight, coated on a support and dried. The coating amount of the layer (photosensitive layer) of the photosensitive composition coated on the support varies depending on the use, but generally, the weight after drying is 0.3 to 4.
0 g / m ² is preferred. The smaller the coating amount, the smaller the exposure amount for obtaining an image, but the film strength decreases. As the coating amount increases, the exposure amount is required, but the photosensitive film becomes stronger. For example, when used as a printing plate,
A printing plate with a high printable number (high printing durability) can be obtained. A surfactant for improving the coated surface quality can be added to the photosensitive composition as in the case of the positive photosensitive composition described above. In the production of the photosensitive lithographic printing plate, either the back coat layer on the back side or the photosensitive composition layer on the front side may be coated on the support first, or both may be coated simultaneously.

On the back surface of the support of the photosensitive lithographic printing plate (PS plate) of the present invention, a coating layer made of an organic polymer compound (hereinafter, this coating layer is used as a back layer) for preventing scratching of the photosensitive layer when it is overlaid. A coat layer) is provided as needed.
The main component of this back coat layer is glass transition point 2
At least one resin selected from the group consisting of a saturated copolyester resin, a phenoxy resin, a polyvinyl acetal resin and a vinylidene chloride copolymer resin having a temperature of 0 ° C. or higher is used. The saturated copolyester resin is composed of a dicarboxylic acid unit and a diol unit. Examples of the dicarboxylic acid unit of the polyester used in the present invention include aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, tetrabromophthalic acid and tetrachlorophthalic acid; adipic acid, azelaic acid, succinic acid, oxalic acid and suberic acid. , Sebacic acid, malonic acid, saturated aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and the like.

The back coat layer further comprises a dye or pigment for coloring, a silane coupling agent for improving adhesion to an aluminum support, a diazo resin containing a diazonium salt, an organic phosphonic acid, an organic phosphoric acid and a cation. Waxes, higher fatty acids, higher fatty acid amides, silicone compounds composed of dimethylsiloxane, modified dimethylsiloxane, polyethylene powder and the like, which are usually used as a slip agent, are appropriately added. The thickness of the back coat layer is basically sufficient as long as it does not damage the photosensitive layer even if there is no interleaving paper, and the range of 0.01 to 8 μm is preferable. If the thickness is less than 0.01 μm, it is not possible to prevent scratches on the photosensitive layer when the PS plates are stacked and handled. If the thickness exceeds 8 μm, the back coat layer may swell due to the chemicals used around the printing plate during printing, the thickness may change, and the printing pressure may change to deteriorate the printing characteristics. Various methods can be applied to coat the back coat layer on the back surface of the aluminum support. For example, make a solution in a suitable solvent,
Alternatively, a method of forming an emulsified dispersion and coating and drying, for example, a method of laminating a film-shaped product in advance with an adhesive or heat to an aluminum support, and a method of forming a molten film with a melt extruder and laminating to a support Etc., but the most preferable method for ensuring the above-mentioned coating amount is a method of forming a solution and coating and drying. As the solvent used here, the organic solvents described in JP-A-62-251739 are used alone or in combination.

On the surface of the photosensitive layer provided as described above, a matte layer is provided in order to shorten the vacuuming time during contact exposure using a vacuum baking frame and prevent baking blur. Specifically, a method of providing a mat layer as described in JP-A-50-125805, JP-B-57-6582, and JP-A-61-28986, and JP-B-62-62337. Examples of the method include heat fusion of the solid powder as described above. The average diameter of the mat layer used in the present invention is preferably 100 μm or less,
When the average diameter is larger than this, when the PS plates are stored in piles, the contact area between the photosensitive layer and the backcoat layer increases, the slipperiness decreases, and scratches occur on the surfaces of both the photosensitive layer and the backcoat layer. easy. The average height of the mat layer is 10μ
m or less is preferable, and more preferably 2 to 8 μm.
If the average height is higher than this range, it is difficult to attach fine lines and the number of highlight dots decreases, which is not preferable for tone reproduction. When the average height is 2 μm or less, vacuum adhesion is insufficient and burning blur occurs. The coating amount of the matte layer is preferably 5 to 200 mg / m ² , more preferably 20 to 150 mg / m ² . If the coating amount is larger than this range, the contact area between the photosensitive layer and the back coat layer increases, causing scratches. If the coating amount is smaller than this range, the vacuum adhesion becomes insufficient.

The PS plate thus obtained was passed through a transparent original image through a carbon arc lamp, a mercury lamp, a metal halide lamp,
After being exposed to an actinic ray using a xenon lamp, a tungsten lamp, or the like as a light source, development processing is performed. As a developer and a replenisher for such a PS plate, a conventionally known alkaline aqueous solution can be used. For example, sodium silicate, potassium, sodium triphosphate, potassium, ammonium, dibasic sodium, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium hydrogencarbonate, potassium, Inorganic alkaline agents such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium are mentioned. Further, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkaline agents such as ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline agents may be used alone or in combination of two or more. Among these alkaline agents, an aqueous solution of silicate such as sodium silicate or potassium silicate is particularly preferable as the developer for positive PS plate. The reason is that the ratio of silicon oxide SiO ₂ which is a component of silicate and alkali metal oxide M ₂ O (generally [Si / [M ₂ O]
This is because the developability can be controlled by the concentration and the concentration. For example, the molar ratio of SiO ₂ Na ₂ O as disclosed in JP-A-54-62004 is 1. 0 to
1.5 (that is, [SiO _2] / [Na ₂ O] is 1.0 to 1.5) der SiO ₂
Aqueous solution of sodium silicate having a content of 1 to 4% by weight, and [SiO ₂ ] / [M] of 0.5 to 0.75 (that is, as described in JP-B-57-727). SiO ₂ ] /
[M ₂ O] is 1.0 to 1.5) and the concentration of SiO ₂ is 1 to 4
Aqueous solutions of alkali metal silicates are preferably used which are in weight percent and contain at least 20% potassium, based on the total alkali metal gram atoms present therein.

Further, when the PS plate is developed using an automatic processor, an aqueous solution (replenisher) having a higher alkaline strength than the developing solution is added to the developing solution, whereby the developing solution in the developing tank for a long time is added. It is known that a large number of PS plates can be processed without replacing the plate. Also in the present invention, this replenishment system is preferably applied. For example, the SiO ₂ / Na ₂ O ratio of a developer as disclosed in JP-A-54-62004 is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na
₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4% by weight is used, and the amount is continuous depending on the throughput of the positive photosensitive lithographic printing plate. Si intermittently or intermittently
If the molar ratio of O ₂ / Na ₂ O is 0.55 (that is, [SiO ₂ ] / [Na ₂ O] is
0.5-1.5) aqueous solution of sodium silicate (supplement) is added to the developing solution, and further, [SiO ₂ ] / [M] is disclosed in Japanese Patent Publication No. 57-7427. 5 to 0.75 (that is, [SiO ₂ ] / [M ₂ O] is 1.0) and the concentration of SiO ₂ is 1 to 4% by weight. The alkali metal silicate [Si
O ₂ ] / [M] is 0.25 0.75 (that is [SiO ₂ ] / [M ₂ O]
Is 0.5-1.5), and both the developer and replenisher contain at least 20% potassium, based on the grams of total alkali metal present therein. The developing method consisting of is preferably used.

When an alkali metal silicate is used as the replenishing solution, the replenishing solution becomes highly active and the replenishing amount can be increased by reducing the molar ratio [SiO ₂ ] / [M ₂ O]. Running cost and amount of waste liquid are reduced, which is preferable. However, it is known that the support aluminum of the PS plate is dissolved due to high activation to produce an insoluble matter in the developing solution. As such a highly active developer, an alkali gold silica having a SiO ₂ / M molar ratio of 0.7 to 1.5 and a SiO ₂ concentration of 1.0 to 4.0% by weight is used. It consists of an acid salt aqueous solution, and the replenisher has a SiO ₂ / M ₂ O molar ratio of 0.3-
1. Therefore, a system such as an aqueous solution of an alkali metal silicate having a SiO ₂ concentration of 0.5 to 4.0% by weight is preferably used.
The developer and replenisher used in the development of the positive and negative PS plates may contain various interfaces as necessary for the purpose of promoting or suppressing the developability, dispersing the development residue and enhancing the ink affinity of the printing plate image area. Activators and organic solvents can be added. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial ester. , Sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester , Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial ester, fatty acid diethanolamide,
Nonionic surfactants such as N, N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, trialkylamine oxides, fatty acid salts, abietic acid salts,
Hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate ester salts, linear alkylbenzene sulfonates, branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylphenoxypolyoxyethylenepropyl sulfonates, polyoxy Ethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated tallow oil, sulfate ester salts of fatty acid alkyl esters, alkyl sulfate esters salts,

Polyoxyethylene alkyl ether sulfuric acid ester salts, fatty acid monoglyceride sulfuric acid ester salts, polyoxyethylene alkylphenyl ether sulfuric acid ester salts, polyoxyethylene styryl phenyl ether sulfuric acid ethylene salts, alkyl phosphoric acid ester salts, polyoxyethylene alkyl ether phosphorus Acid ester salts, polyoxyethylene alkyl phenyl ether phosphate ester salts, partial saponification products of styrene / maleic anhydride copolymers, partial saponification products of olefin / maleic anhydride copolymers, naphthalene styrenic acid salt formalin condensates Surfactants such as anionic surfactants, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives and other cationic surfactants Carboxy betaines, aminocarboxylic acids, sulfobetaines, such amino acid esters, amphoteric surfactants such as imidazolines. Among the above-mentioned surfactants, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these surfactants are also included.

A more preferred surfactant is a fluorinated surfactant containing a perfluoroalkyl group in the molecule. Such fluorine-based surfactants include perfluoroalkylcarboxylates, perfluoroalkylsulfonates, anionic types such as perfluoroalkyl phosphates, and amphoteric types such as perfluoroalkylbetaines.
Cationic type and perfluoroalkylamine oxide such as perfluoroalkyltrimethylammonium salt, perfluoroalkylethylene oxide adduct, perfluoroalkyl group- and hydrophilic group-containing oligomer,
Nonionic types such as perfluoroalkyl group- and lipophilic group-containing oligomers, perfluoroalkyl groups, hydrophilic group- and lipophilic group-containing oligomers, and perfluoroalkyl group- and lipophilic group-containing urethanes can be mentioned. The above-mentioned surfactants can be used alone or in combination of two or more kinds, and 0.001 to 10% by weight in the developer,
More preferably, it is added in the range of 0.01 to 5% by weight.

Suitable organic solvents are those having a solubility in water of about 10% by weight or less, preferably 5% by weight or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1.
-Butanol, 2-phenoxyethanol, 2-benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4 -Methylcyclohexanol, N-phenylethanolamine, N-phenyldiethanolamine and the like can be mentioned. The content of the organic solvent is 0.1 to 5% by weight based on the total weight of the used liquid. The amount used is closely related to the amount used of the surfactant, and it is preferable to increase the amount of the surfactant as the amount of the organic solvent increases. This is because when the amount of the surfactant is small and the amount of the organic solvent is large, the organic solvent is not completely dissolved, and it is therefore impossible to expect to secure good developability.

A reducing agent can be further added to the developer and replenisher used for developing the PS plate. This is to prevent stains on the printing plate and is particularly effective when developing a negative PS plate containing a photosensitive diazonium salt compound. Preferable organic reducing agents include phenol compounds such as thiosalicylic acid, hydroquinone, methol, methoxyquinone, resorcin, and 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. More preferable inorganic reducing agents include sodium salts, potassium salts, and ammonium salts of inorganic acids such as sulfurous acid, bisulfite acid, phosphorous acid, hydrogen phosphite, dihydrogen phosphite, thiosulfuric acid and dithionous acid. Examples thereof include salt. Among these reducing agents, sulfite has a particularly excellent antifouling effect. These reducing agents are preferably added to the developer at the time of use in an amount of 0.0
It is contained in the range of 5 to 5% by weight.

An organic carboxylic acid may be further added to the developing solution and the replenishing solution. Preferred organic carboxylic acids are aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids. Specific examples of the aliphatic carboxylic acid include caproic acid, enanthic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . Further, it may be an unsaturated fatty acid having a double bond in the carbon chain or a branched carbon chain. The aromatic carboxylic acid is a compound in which a benzene ring, a naphthalene ring, an anthracene ring or the like is substituted with a carboxyl group, and specifically, o-chlorobenzoic acid, p-chlorobenzoic acid,
o-hydroxybenzoic acid, p-hydroxybenzoic acid, o
-Aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid,
2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid,
1-hydroxy-2-naphthoic acid, 3-hydroxy-2
-Naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-
Although there are naphthoic acid and 2-naphthoic acid, hydroxynaphthoic acid is particularly effective. The aliphatic and aromatic carboxylic acids are preferably used in the form of sodium salt, potassium salt or ammonium salt in order to enhance water solubility.
The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but if it is less than 0.1% by weight, the effect is not sufficient, and if it is 10% by weight or more, further improvement of the effect cannot be achieved. Not only that, when other additives are used in combination, dissolution may be hindered. Therefore, the preferable addition amount is 0.1 to 10% by weight with respect to the developing solution at the time of use, and more preferably 0.1.
It is 5 to 4% by weight.

The developer and replenisher may further contain, if necessary, defoaming agents, water softeners, and conventionally known compounds such as organic boron compounds described in JP-B-1-57895. You can Examples of the water softener include polyphosphoric acid and its sodium salt, potassium salt and ammonium salt, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetriacetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid. Acetic acid and aminopolycarboxylic acids such as 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic salt), ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylene) Phosphonic acid), triethylenetetramine hexa (methylenephosphonic acid), hydroxyethylethylenediaminetri (methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts.

The optimum value of such a water softener varies depending on its chelating power, the hardness of the hard water used and the amount of hard water. 0.01-5% by weight, more preferably 0.01-
It is in the range of 0.5% by weight. If the addition amount is less than this range, the intended purpose is not sufficiently achieved, and if the addition amount is more than this range, the image area is adversely affected such as color loss. The remaining component of the developing solution and the replenishing solution is water, but if desired, various additives known in the art can be added. It is advantageous in terms of transportation that the developing solution and the replenishing solution are concentrated solutions having a water content smaller than that at the time of use and are diluted with water at the time of use. In this case, the degree of enrichment should be such that each component does not separate or precipitate.

The PS plate thus developed is post-treated with washing water, a rinse solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. Various combinations of these treatments can be used for the post-treatment of the PS plate of the present invention. In recent years, in the plate making / printing industry, automatic developing machines for PS plates have been widely used in order to rationalize and standardize the plate making work. This automatic developing machine is generally composed of a developing section and a post-processing section, and is composed of an apparatus for conveying a PS plate, each processing solution tank and a spraying apparatus, and the exposed PS
While the plate is conveyed horizontally, each processing solution pumped up by a pump is sprayed from a spray nozzle to perform development processing. Further, recently, a method has also been known in which a PS plate is dipped and conveyed by a submerged guide roll or the like in a treatment liquid tank filled with the treatment liquid for treatment. In such automatic processing, it is possible to perform processing while supplementing each processing solution with a replenishing solution according to the processing amount, operating time, and the like.

[0051]

Example: JIS A 1050 aluminum plate with a thickness of 0.24 mm
3 types of surfaces with different surface grain shapes
Treatment, followed by 1% aqueous sodium hydroxide solution
Soak in 40 ° C for 30 seconds, then in 30% sulfuric acid solution
20% after soaking and desmutting at 60 ℃ for 40 seconds
Current density 5A / dm in sulfuric acid solution²At 1.6 g /
m²Anodize with direct current so that the weight of the oxide film of
A plate was made. [Surface treatment A] A suspension of pumice and water in aluminum
Nylon brush with a diameter of 0.57 to 0.72 mm while supplying it to the surface
Brush pressing was performed by changing the pressure of the brush. bra
After rinsing, wash well with water and then use 10% hydroxy acid.
Immerse in sodium chloride solution at 60 ° C for 25 seconds and etch.
And rinse with running water, then neutralize with 20% nitric acid
Cleaned and washed with water. These are used by the alternating wave current of the sine wave.
, 100-600 coulomb / dm in 1% nitric acid solution²
Electrolytic surface roughening treatment was performed with the amount of electricity at the time of the anode. [Surface treatment B] Adhere to the surface with 10% sodium hydroxide
After removing the rolling oil, neutralized and washed in 20% nitric acid,
After washing, in a 1% nitric acid electrolytic solution, cool 100 to 600
/ Dm ²Electrolytic surface roughening treatment was performed with the amount of electricity at the time of the anode. [Surface treatment C] Adhere to the surface with 10% sodium hydroxide
After removing the rolling oil, neutralized and washed in 20% nitric acid,
After washing, in a 1% hydrochloric acid electrolytic solution, cool 100 to 600
/ Dm ²Electrolytic surface roughening treatment was performed with the amount of electricity at the time of the anode.

An undercoat liquid having the following composition was applied to the surface of the substrate thus treated and dried at 80 ° C. for 30 seconds. The coating amount after drying was 30 mg / m ² . Undercoating liquid Aminoethylphosphonic acid 0.10 g Phenylphosphonic acid 0.15 g β-alanine 0.10 g Methanol 40 g Pure water 60 g The following photosensitive liquids were coated on the substrate thus prepared by changing the coating amount, and 110 After drying at 0 ° C. for 1 minute, 18 types of positive photosensitive lithographic printing plates shown in Table 1 were obtained.

[Photosensitive Solution] Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) 0.45 g Cresol-formaldehyde novolak resin (meta-para ratio; 6 to 4, weight average molecular weight 3,000, number average molecular weight 1,100, containing 0.7% unreacted cresol) 1.1 g m-cresol-formaldehyde novolac resin (weight average molecular weight 1,700, number average molecular weight 600, containing 1% of unreacted cresol) 0.3 g poly [N- (P-aminosulfonylphenyl) acrylamide-co-normal butyl acrylate-co-diethylene glycol monomethyl ether methacrylate] (The molar ratio of each monomer is 40:40:20, the weight average molecular weight is 40,000, Number average molecular weight 20,000) 0.2 g

P-Normal octylphenol-formaldehyde resin (as described in US Pat. No. 4,123,279) 0.02 g naphthoquinone-1,2-diazide-4-sulfonic acid chloride 0.01 g tetrahydrophthalic anhydride 0.1. 1 g Benzoic acid 0.02 g 4- [p-N, N-bis (ethoxycarbonylmethyl) aminophenyl] -2,6-bis (trichloromethyl) -S-triazine 0.01 g 4- [PN- (P -Hydroxybenzoyl) aminophenyl] -2,6-bis (trichloromethyl) -S-triazine 0.02 g 2-trichloromethyl-5- (4-hydroxystyryl) -1,3,4-oxadiazole 0.01 g Victoria Pure Blue BOH Dye with 1-naphthalenesulfonic acid as the counter anion 0.02g

MODIPER F-200 (Nippon Oil & Fats Co., Ltd. Fluorine-based surfactant, 30 wt% methyl ethyl ketone and methyl isobutyl ketone mixed solvent solution) 0.06 g Megafac F177 (Dainippon Ink and Chemicals, Inc. Fluorine -Based surfactant, 20% by weight methyl isobutyl ketone solution) 0.02 g methyl ethyl ketone 15 g 1-methoxy-2-propanol 10 g

On the photosensitive layer thus coated, according to the method described in JP-B No. 61-28986, Example 1, (methyl methacrylate / ethyl acrylate / sodium acrylate = 68/20 / A mat layer was provided by electrostatically spraying the aqueous copolymer solution of 12).
The photosensitive lithographic printing plate thus prepared was exposed through a transparent positive film through a transparent positive film from a distance of 1 m with a metal halide lamp of 3 kw for 50 seconds, and then SiO ₂ / Na ₂ was used as a developing solution. O molar ratio is 1.74
5.26% aqueous solution of Natom Silicate (pH = 12.7) was used as a rinsing solution and was manufactured by Fuji Photo Film Co., Ltd. FR-3 (1:
Processing was carried out through an automatic processor Stablon 900D manufactured by Fuji Photo Film Co., Ltd. in which 7) was charged. These 18 types of positive photosensitive lithographic printing plates were evaluated by printing. The printer is SOR-M made by Heidelberg, the dampening water is EU-3 (1: 100) made by Fuji Photo Film Co., Ltd. with 10% isopropanol added, and the ink is Mark Five made by Toyo Ink Co., Ltd. New ink was used. Regarding the stain on the shadow portion, it was judged by whether or not 80% halftone dots of the printed matter when the dampening water was squeezed on the printing machine were open.
The degree of stain on the shadow portion is indicated by the following display. ◎ ・ ・ ・ Fully open ○ ・ ・ ・ Almost open
△: Somewhat clogged ×: Quite clogged It should be noted that it is at a level of ◯ or higher that a preferable printed matter with a small shadow portion is obtained. Relation of formula (1): ◯ ... Satisfied ×: Not satisfied As a result, as shown in Table 1, the planographic printing plate of the invention (Sample Nos. 1 and 2) satisfying the relation of formula (1) is satisfied. 4, 5,
Nos. 6, 9, 10, 11, 13, 16 and 18) did not generate stains on the shadow portion even if the dampening water was reduced.

[0057]

[Table 1] Sample surface ^* Ra ^* TRa ^* ΔRa Shadow method (1) No. treatment [μm] [μm] [μm] Relation of dirt on the part ────────────────────── ─────────────── 1 A 0.41 0.27 0.14 ◎ ○ 2 A 0.59 0.43 0.16 ◎ ○ 3 A 0.46 0.16 0.30 × × 4 A 0.72 0.47 0.25 ◎ ○ 5 A 0.84 0.55 0.29 ◎ ○ 6 A 0.52 0.29 0.23 ○ ○ 7 B 0.56 0.16 0.40 × × 8 B 0.35 0.11 0.24 × × 9 B 0.23 0.20 0.03 ○ ○ 10 B 0.30 0.22 0.08 ○ ○ 11 B 0.53 0.38 0.15 ◎ ○ 12 B 0.61 0.14 0.47 × × 13 C 0.49 0.41 0.08 ◎ ○ 14 C 0.71 0.26 0.45 △ × 15 C 0.65 0.28 0.37 △ × 16 C 1.02 0.71 0.31 ◎ ○ 17 C 0.80 0.26 0.54 △ × 18 C 0.92 0.52 0.40 ○ ○ ───────── ───────────────────────── [* Ra = Surface roughness of support (stylus 10 μR) TRa = Surface of photosensitive layer after development And (stylus 10μR) ΔRa = Ra-TRa] surface roughness was measured using a Tokyo Seimitsu Co., Ltd. SURFCOM stylus meter.

EFFECTS OF THE INVENTION Since the shadow portion on the printing machine is less likely to become dirty, it is easy to print even for an unskilled person, and a printed matter of higher quality and more stable than the conventional one can be obtained.

Claims (1)

[Claims] 1. A photosensitive lithographic printing plate in which a photosensitive layer is provided on the surface of a roughened support, the surface roughness (Ra) (μm) of the surface of the support, and Ra and the photosensitive property after development. Difference (ΔRa) (μm) from the surface roughness (TRa) (μm) of the layer surface
Is a photosensitive lithographic printing plate characterized by satisfying the following relational expression. ΔRa ≦ 0.6 × Ra−0.05 (1)