JPH02294650A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To provide the above printing plate which has excellent developability and high plate wear even under printing conditions under which alkaline damping water is used by using a high-polymer compd. contg, a specific structural unit as a high-polymer compd. CONSTITUTION:The high-polymer compd. of the lithographic printing plate formed by providing a photosensitive layer consisting of a diazonium resin and the high-polymer compd. on an aluminum sheet which is subjected to a sand dressing and anodic oxidation treatment contains the structural unit expressed by formula I. In the formula I, R1 denotes a hydrogen atom, halogen atom, alkyl group; R2 and R3 respectively denote a hydrogen atom, alkyl group; R4 denotes an alkyl group, alkoxy group; m denotes 1 to 3 integer; n denotes 0 to 4 integer; Z denotes -O-, -NH-. The printing plate which has the high plate wear in the printing using the alkaline damping water and the excellent developability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a negative photosensitive lithographic printing plate, and more specifically to a negative photosensitive lithographic printing plate that has excellent developability and stiffness resistance when using alkaline detergent water. This invention relates to a type photosensitive lithographic printing plate.

(Prior Art) The majority of those used as photolactic substances in pre-sensitized printing materials are diazonium compounds, the most commonly used of which is P-diazodiphenylamine. There are diazonium resins represented by formaldehyde condensates.

When such diazonium resin is coated on a suitable support such as paper, plastic or metal and exposed to actinic light through a transparent negative, the diazonium resin in the exposed areas decomposes and becomes insoluble. do. On the other hand, by dissolving and removing the unexposed areas with water, the surface of the support that has been subjected to the hydrophilic treatment is exposed. Therefore, on an offset printing press, this unexposed area accepts water and repels ink. In addition, the decomposed portion of the diazonium resin exhibits lipophilic properties, repelling water and accepting ink. Such printing materials give so-called negative printing plates. The composition of the photosensitive layer of this type of photosensitive printing material can be classified into diazonium resin alone or a mixture of diazonium resin and a polymer compound, and is generally advantageous in terms of stiffness resistance. The latter system is used.

Such polymer compounds include, for example, Japanese Patent Publication No. 55-3
A copolymer of (meth)acrylic acid and (meth)acrylonitrile having an alcoholic hydroxyl group as described in JP-A No. 4929, (meth) as described in JP-A-56-4144 Alkyl acrylate and (
Copolymers of meth)acrylonyl-1-lyl and unsaturated carboxylic acids, (meth)acrylamides containing aromatic hydroxyl groups as described in Japanese Patent Publication No. 57-43890, or (meth)acrylic acid Ester, copolymer of (meth)acrylonitrile and unsaturated carboxylic acid, etc. are known.

(Problems to be Solved by the Invention) However, although conventional photosensitive compositions have relatively good stiffness resistance in normal printing using neutral to acidic dampening water, they do not tolerate alkaline resistance in newspaper printing, etc. It cannot be said that the rigidity is necessarily sufficient under printing conditions using dampening water.
Improvement was desired.

Additionally, in order to improve the printing durability under such conditions, it may be possible to further add a resin with good abrasion resistance, but in such a case, the solubility of the entire photosensitive layer generally decreases. This problem arises as a decrease in the developability of the photosensitive lithographic printing plate, that is, the dissolution rate of the unexposed light-absorbing layer, the solubility of the developer, etc., and becomes a problem in practical plate making. Therefore, the main object of the present invention is to provide excellent developability and
The object of the present invention is to provide a novel photosensitive lithographic printing plate that exhibits high printing durability even under printing conditions using alkaline dampening water.

(Means for Solving the Problems) The present inventors have taken note of the above problems and, as a result of intensive studies, have determined that a polymer compound containing a structural unit represented by the following general formula (I) should be used as a polymer compound. In other words, we have found that the intended purpose can be achieved, and have completed the present invention. That is, the gist of the present invention is to provide a lithographic printing plate in which a photosensitive layer consisting of a diazonium resin and a polymer compound is provided on a grained and anodized aluminum plate, in which the cough polymer compound has the following general formula (I ) is characterized by containing the structural unit shown by. General formula (wherein R. represents a hydrogen atom, a halogen atom, or an alkyl group, R2 and R. represent a hydrogen atom or an alkyl group, respectively, R4 represents an alkyl group or an alkoxy group, and m is 1 to 3, n represents an integer from 0 to 4, and Z represents 101-NH1.) Hereinafter, the present invention will be described in detail.

As the diab resin used in the present invention, conventionally known ones can be used, but diazo resins in which aromatic diazonium salts are condensed with active carbonyl, for example, with formaldehyde, are typically used. In addition, a diazo resin co-condensed with an aromatic diazonium salt, an aromatic sulfonic acid (salt) compound, etc., and formaldehyde is also used. As the diazonium resin, for example, a condensate of p-diazodiphenylamine and formaldehyde or acetaldehyde, p- A diazonium resin inorganic salt which is an organic solvent-soluble reaction product of a cocondensate of diazodiphenylamine and benzenesulfonic acid (salt) with formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate, or US Pat. ,300.30
9 and sulfonic acids such as p-toluenesulfonic acid or its salts, phosphinic acids such as benzenephosphinic acid or its salts, hydroxyl group-containing compounds such as 2,4-dihydroxy Examples include organic solvent-soluble diazonium resin organic acid salts such as benzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, or salts thereof.

Specific examples of diazonium resins include 4-diazodiphenylamine hexafluorophosphate-formaldehyde resin, 4-diazodiphenylamine hexafluorophosphate monoa-heptaldehyde resin, and 4-diazo 4'-methoxydiphenylamine tetrafluoroboric acid. Salt-formaldehyde resin, 4-diazo-4'-ethoxydiphenylamine/tetrafluoroborate mono-7toaldehyde resin, benzenesulfonic acid-4-diazodiphenylamine/tetrafluoroborate-formaldehyde resin, benzenesulfonic acid ( salt) ~4-diazodiphenylamine tetrafluoroborate monoacetaldehyde resin, 4-diazodiphenylamine 2-hydroquine-4-
Examples include methoxyhenzophenone-5-sulfonate monoformaldehyde resin.

The diazonium resin of the present invention can have any molecular weight by varying the molar ratio of each monomer and the condensation conditions, but in order to effectively meet the intended use of the present invention, Those with a molecular weight of 400 to toooO can be used, but preferably about 800 to 500
A value of 0 is appropriate.

The photosensitive diazonium resin used in the present invention is usually 1 to
The content is 60% by weight, preferably 3 to 30mWk%.

On the other hand, the polymer compound containing the structural unit represented by the general formula (I) used in the present invention can be obtained by polymerizing a compound represented by the following general formula (■).

Preferably, it is obtained by copolymerizing this with a polymerizable addition-polymerizable unsaturated compound.

General formula (in the formula, R+, Rz, Rs, R4, Z, m, 'n each represent the same as mentioned above). Examples of the above-mentioned addition polymerizable unsaturated compound include acrylamides, methacrylamide, etc. Selected from compounds with addition-polymerizable unsaturated bonds such as α, β monounsaturated carboxylic acids, (substituted) alkyl acrylates, (substituted) alkyl methacrylates, vinyl ethers, vinyl esters, vinyl ketones, styrenes, olefins, etc. It will be done.

Specific examples include those shown in (I) to (I0) below. (I) α, β monounsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride (2) Methyl acrylate, ethyl acrylate, probyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, acrylic Octyl acid, acrylic acid-
(Substituted) alkyl acrylates such as 2-chloroethyl, 2-hydroxyethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl acrylate (3)
Methyl methacrylate, ethyl methacrylate, proyl methacrylate, butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, 2-
(Pentameric) alkyl methacrylates such as hydroxyethyl meccrylate, 4-hydroxybutyl methacrylate, glucidyl methacrylate, N-dimethylaminoethyl methacrylate (4) Acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, N monoethyl acrylamide, N-hexylmethacrylamide, N-cyclohexyl acrylamide, N-
Hydroxyethyl acrylamide, N-phenylacrylamide, N-hydroxyphenylmethacrylamide,
Acrylamides or methacrylamides such as N-ethyl-N-phenylacrylamide (5) Vinyl ethers such as eltivinyl ether, 2-chloroeltivinyl ether, hydroxyethyl vinyl ether, probyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc. (6) Vinyl Vinyl esters such as acetate, vinyl chloroacetate, vinyl butyrate, and vinyl benzoate (styrenes such as castyrene, α-methylestyrene, methylestyrene, and chloromethylstyrene (8)
Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, probyl vinyl ketone, phenyl vinyl ketone, etc. (9) Olefins such as ethylene, brobylene, isobutylene, butadiene, isobrene, etc. Examples include -vinylpyridine, acrylonitrile, and methacrylic nitrile, but any other monomers may be used as long as they are copolymerizable with the monomer represented by the above general formula (II), and the present invention is not limited thereto. Other resins include polyvinyl butyral resin, polyurethane resin, polyamide resin, epoxy resin, novolak resin, polyvinyl formal resin, polyester resin, polycarbonate resin, and natural resin.

Particularly preferred addition-polymerizable unsaturated compounds include acrylic acid, methacrylic acid, and the like. β-monounsaturated carboxylic acids,
(Substituted) alkyl acrylates such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate, (IIA) alkyl methacrylates, and acryl di[·lyl, methacryl nitrile].

The copolymer of the present invention can be obtained by a conventional method, and the content of the structural unit represented by the general formula (+) in the copolymer is 1 to 50 mol%, more preferably 5 to 30 mol%.
It is ol%. In addition, the molecular weight is preferably in the range of 10,000 to 300,000 (hereinafter abbreviated as GPC as measured by gel vermiform chromatography), and more preferably in the range of 20,000 to 250,000.

The polymer compound used in the present invention includes, in the photosensitive composition,
The content is 1 to 99% by weight, more preferably 5 to 95% by weight.

In addition to the materials described above, dyes, pigment coating improvers, plasticizers, and the like may be added to the photosensitive composition of the present invention, if necessary.

Examples of the dye include Victoria Pure Blue B.
OH (manufactured by Hodogaya Chemical Co., Ltd.), Oil Blue #603 (
Orient Chemical Co., Ltd.), Patent Pure Blue (Sumitomo Mikuni Chemical Co., Ltd.), Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosin B, Paysic Fuchsin, Malachite Green, Oil Lend, m-Cresol Purple, Rhodamine B1 Triphenylmethane-based typified by auramine, 4-P-diethylaminophenylimino-naphthoquinone, cyano-P-diethylaminophenyl acetanilide, etc.
Examples include diphenylmethane-based, oxazine-based, xanthene-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes.

The dye is usually present in the photosensitive composition in an amount of about 0. 5-10 times 4%
, preferably about 1 to 5% by weight.

Examples of coating improvers include alkyl ethers (e.g., ethyl cellulose, methyl cellulose), fluorine-based surfactants, and nonionic surfactants (e.g., Pluronic L).
64 (manufactured by Asahi Denka Co., Ltd.)], and the flexibility of the coating film and the resistance to
Examples of the plasticizer for imparting wear resistance include butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, diethylhexyl phthalate, tricresyl phosphate, Examples include oligomers of tributyl phosphate, trioctyl phosphate, tetrafurfuryl oleate, acrylic acid, and methacrylic acid. The half-esterified product of styrene-maleic anhydride copolymer with alcohol described in No. 527 can be mentioned, and examples of the stabilizer include polyacrylic acid, tartaric acid, phosphoric acid, phosphorous acid, and organic acids (acrylic acid, methacrylic acid, citric acid). , oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, 4-methoxy-2-hydroxybenzophenone-5-sulfone, etc.). The amount of these additives added varies depending on the purpose for which they are used, but is generally preferably 0.01 to 30% by weight based on the total solid content.

In the present invention, the above-mentioned photosensitive composition is used in a suitable solvent, for example, cellosolves such as methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, methyl ethyl ketone, ethyl acetate, benzyl alcohol, diacetone alcohol, etc. , dimethylformamide, dimethylsulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, etc., either alone or in combination of two or more, to prepare a photosensitive liquid.

A photosensitive lithographic printing plate is obtained by applying this onto the surface of a support and drying it.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating can be used. The coating amount varies depending on the application, but for photosensitive planographic printing plate materials, the solid content is O. 15 to 10 g/m" is preferred.

The support of the photosensitive lithographic printing plate of the present invention is preferably an aluminum plate, which has been subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. Known methods can be applied to these treatments.

Examples of the graining treatment include a mechanical method and an electrolytic etching method.

Examples of mechanical methods include ball polishing, brush polishing, liquid honing, and puff polishing. The various methods described above can be used alone or in combination depending on the composition of the aluminum material.

Electrolytic etching is performed in a bath containing an inorganic acid such as hydrochloric acid or nitric acid.

After the graining process, desmutting is performed using an alkali or acid aqueous solution as necessary to neutralize the material, followed by washing with water.

The anodic oxidation treatment is carried out by using an electrolytic solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc., and using an aluminum plate as an anode. The amount of formed anodic oxide skin III is 1 to 50 ■
/dn+2 is suitable, preferably 10 to 40 mg/d
a+", particularly preferably 25 to 40 ■/dta"
It is. The amount of anodized film can be determined, for example, by dissolving an aluminum plate in phosphoric acid chromic acid solution (85% phosphoric acid solution: 35 ml, chromium oxide (Vl): 20 g in water of II!).
It is determined by dipping the plate in water to dissolve the oxide film and measuring the weight change before and after the film is dissolved.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum plate support may be subjected to a subbing treatment using an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate.

In addition, when contact-baking a film original onto a photosensitive lithographic printing plate material, the printing frame is generally vacuumed, but a method for improving this vacuum adhesion is also photosensitive lithographic printing using the photosensitive composition of the present invention. Can be used for plate materials. Methods for improving vacuum adhesion include mechanically creating unevenness on the surface of the photosensitive layer, scattering solid powder on the surface of the photosensitive layer,
A method of providing a matte layer on the surface of a photosensitive layer as described in JP-A-50-125805, and JP-A-55
Examples include a method of heat-sealing a solid powder onto the surface of a photosensitive layer, as described in Japanese Patent No. 12974.

The photosensitive lithographic printing plate material coated on the support can be prepared by conventional methods. That is, by exposing a transparent original image having a line image, a halftone image, etc. to light, and then developing it with an aqueous developer, a negative relief image can be obtained with respect to the original image. Light sources suitable for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, and the like.

The developing solution used in the development of the photolucent lithographic printing plate material of the present invention may be any known developer, but the following are preferred. That is, the developer for developing the photosensitive lithographic printing plate material of the present invention contains a specific organic solvent, an alkaline agent, and water as essential components. Here, the specific organic solvent is one that can dissolve or swell the non-exposed area (non-image area) of the above-mentioned photosensitive composition layer when contained in the developer, and that is capable of dissolving or swelling at room temperature (20°C). An organic solvent with a solubility in water of 10% by weight or less. Such organic solvents only need to have the above-mentioned characteristics, and are not limited to the following, examples of which include ethyl acetate, proyl acetate, and acetic acid. Carboxylic acid esters such as butyl, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate, etc. Ketones such as ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.: ethylene glycol monobutyl ether, ethylene glycol benzyl ether, Alcohols such as ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; halogenation of methylene dichloride, ethylene dichloride, monochrome benzene, etc. Hydrocarbons, etc. One or more of these organic solvents may be used. Among these organic solvents, ethylene glycol monophenyl ether and benzyl alcohol are particularly effective. Further, the content of these organic solvents in the developing solution is approximately 1 to 20% by weight, and particularly preferable results are obtained when the content is 2 to 10% by weight.

On the other hand, the alkaline agent contained in the developer includes (A) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium or ammonium salt of dibasic or tertiary phosphoric acid; Inorganic alkali IJ agents such as sodium metasilicate, sodium carbonate, ammonia, etc. (B) Mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or diisobutylamine, n-
Examples include organic compounds such as butylamine, mono-, di- or triethanolamine, mono-, di- or triisobrobanolamine, ethyleneimine, ethylenediamine.

Preferred are (A) potassium silicate and sodium silicate, and CB) organic amine compounds, and particularly preferred are (A) potassium silicate and (B) di- or triethanolamine.

The content of these alkaline agents in the developer is usually 0.
0.05 to 8% by weight, preferably 0.05 to 8% by weight. It is 5 to 6% by weight.

Further, in order to further improve storage stability, rigidity resistance, etc., it is preferable to include a water-soluble sulfite in the developer as necessary. Such water-soluble sulfites are preferably alkali or alkaline earth metal salts of sulfite, such as sodium sulfite, potassium sulfite, lithium sulfite, magnesium sulfite, and the like. The content of these sulfites in the developer composition is usually 0.05 to 4% by weight, preferably 0.1 to 1% by weight.

Certain solubilizers may also be included to aid in the dissolution of the organic solvents mentioned above in water.

As such a solubilizing agent, in order to achieve the desired effects of the present invention, it is preferable to use alcohols and ketones that have a lower molecular weight and are more easily soluble in water than the organic solvent used. Furthermore, anionic activators, amphoteric activators, etc. can also be used. Examples of such alcohols and ketones include methanol,
It is preferable to use ethanol, propanol, butanol, acetone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methoxybutanol, ethoxybutanol, 4-methoxymethylbutanol, N-methylpyrrolidone, and the like. Preferred examples of the activator include sodium isobrobylnaphthalene sulfonate, sodium n-butylnaphthalene sulfonate, sodium N-methyl-N-pentadecylaminoacetate, and sodium lauryl sulfate. There is no particular restriction on the amount of solubilizing agents such as alcohols and ketones used, but it is preferably about 30% by weight or less based on the entire developer solution.

After imagewise exposure, the photosensitive lithographic printing plate material of the present invention becomes photosensitive after 10 to 60 seconds at about 10°C to 40°C if it is brought into contact with the above-mentioned developer or rubbed. The photosensitive composition in the unexposed areas of the layer is completely removed without adversely affecting the exposed areas of the layer, and a lithographic printing plate is obtained.

(Example) The present invention will be explained in more detail below using examples.

Production Example 1 (Synthesis of Polymer Compound-1) N-(4-methoxyphenyl) methacrylamide 28.
7g of acrylonitrile, 13.3g of acrylonitrile, 55g of edyl acrylate, 4.3g of methacrylic acid, and 1.6g of azobisisobutyronitrile (AIBN) were dissolved in 110ml of acetone-methanol 1:1 mixed solvent, and under a nitrogen stream,
The reaction was carried out by heating at 60°C for 8 hours. After the reaction was completed, the reaction solution was poured into water 51 with stirring, and the resulting white precipitate was collected and dried to obtain 85% of polymer compound-1.

When the molecular weight of this was measured by GPC, the weight average molecular weight was 8,50,000.

Production example-2 (Synthesis of polymer compound-2) N-(4-ethylphenyl)acrylamide 53.3
g, Acrylic nitrile 1 0. 6 g, methyl acrylate 1-3 4. 4 g of methacrylic acid and 866 g of methacrylic acid were reacted in the same manner as in the case of 1 liter of polymer compound to obtain 91 g of polymer compound-2.

When the molecular weight of this was measured by GPC, the weight average molecular weight was about 85,000.

Production Example-3 (Synthesis of Polymer Compound-3) If-(3,5-dimethoxyphenyl)methacrylamide 22. Og, acrylonitrile 1 0. 6 g,
Ethyl acrylate} 15.5g, ethyl acrylate 4
5 g of methacrylic acid and 6 g of methacrylic acid were reacted in the same manner as in the case of Polymer Compound-1 to obtain 82 g of Polymer Compound-3. When the molecular weight of this was measured by GPC, the weight average molecular weight was approximately 90,000. Production example-4 (Synthesis of polymer compound-4) N-(4-methoxyphenyl) methacrylamide 9.6
g. ．． 8.9 g of N-(4-hydroxyphenyl) methacrylamide, 1 acrylonitrile 3. 3 g, ethyl methacrylate 63 g, methacrylic acid 8.6 g,
AIBN was adjusted to 0.8 g and reacted in the same manner as in the case of Polymer Compound 1, to obtain 91 g of Polymer Compound 4.

When the molecular weight of this was measured by GPC, the weight average molecular weight was about 130,000.

Production example-5 (Synthesis of polymer compound-5) 17.6 g of benzyl methacrylate, 1 acrylonitrile
2. 7 g, methyl methacrylate 1 2. 9
g Ethyl acrylate 46g Methacrylic l 14.3
g was reacted in the same manner as in the case of polymer compound-1 to obtain 75 g of polymer compound-5.

When the molecular weight of this was measured by GPC, the weight average molecular weight was about 90,000.

Production example-6 (Synthesis of polymer compound-6) Benzyl acrylate 1]. 3g, 1 acryloni, 1 rill
4. 3 g, methyl methacrylate 1 2. 9
g Ethyl acrylate 46g Methacrylic M4.3
g was reacted in the same manner as in the case of polymer compound-1 to obtain 71 g of polymer compound-6.

When the molecular weight of this was measured by GPC, the weight average molecular weight was about 90,000.

Production Example-7 (Synthesis of Diazonium Resin-1) 14.5 g (50 mmol) of p-diazodiphenylamine sulfate was mixed with 40.0 g of p-diazodiphenylamine sulfate under water cooling. Dissolved in 9 g of concentrated sulfuric acid. After this reaction I. 5 g (50 mmol) of rose formaldehyde was slowly added dropwise. At this time, the addition was carried out so that the reaction temperature did not exceed 10°C. After that, 2
Stirring was continued under water cooling for an hour.

This reaction mixture was added dropwise to 500++42 ethanol under water cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 100 mf of pure water, and to this solution was added a cold concentrated aqueous solution in which 6.8 g of zinc chloride was dissolved.

The resulting precipitate was filtered, washed with ethanol, and washed with 1
It was dissolved in 50 mf of pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was filtered, washed with water, and then dried at 30°C for one day and night to obtain diazonium resin-1.

When the molecular weight of this product was measured by GPC, it was found to be about 2,400 in terms of weight average molecular weight.

Production Example-8 (Synthesis of Diazonium Resin-2) Diazonium Resin-2 was synthesized in the same manner as in the case of Diazonium Resin-1, except that the amount of paraformaldehyde was changed to 1.2 g (40 mmol).

When the molecular weight of this product was measured by GPC, it was found to be about 1,700 in terms of weight average molecular weight.

Production Example-9 (Synthesis of Diazonium Resin-3) 11 g (37.5 mmol) of p-diazodiphenylamine sulfate, 2.3 g (I2.
5 mmol), rose formaldehyde 3.5 g (45
mmol) and synthesized in the same manner as in the case of Diazonium Resin-1 and co-condensed to obtain Diazonium Resin-3.

When the molecular weight of this product was measured by GPC, it was found to be about 2200 in terms of weight average molecular weight.

Production Example-10 (Synthesis of Diazonium Resin-4) Hexafluoroammonium phosphate of Diazonium Resin-2 was converted into 2-hydroxy-4-methoxybenzophenone-
5-Sulfonate 1. 5. Except for changing to 5 g.
Diazonium resin-2 in the same manner as diazonium resin-2
I got 4. When the molecular weight of this product was measured by GPC, it was found to be about 1,700 in terms of weight average molecular weight.

Production example-11 (Production of grain) Thickness 0. A 24 tm aluminum plate was immersed in a 3% aqueous sodium hydroxide solution to degrease it, washed with water, electrolytically etched in a 1% aqueous hydrochloric acid solution at 25"C for 5 minutes at a current density of 3A/dmz, and washed with water. % aqueous sodium hydroxide solution, washed with water, anodized in a 40% aqueous sulfuric acid solution at 30° C. for 2 minutes at a current density of I.5 A/dwr!, washed with water, and then anodized in a 1% aqueous sodium metasilicate solution 85% aqueous sodium metasilicate solution.゜C,
The pores were sealed for 30 seconds, washed with water, and dried to obtain an aluminum plate for planographic printing.

Examples 1 to 4, Comparative Examples 1 to 2 A photosensitive solution having the composition shown below was applied to the aluminum plate obtained as described above using a whirler to give a photosensitive layer thickness of 1.6.
g/tmz~1.7 gerIl" Tonaruyou C'
:-'! The cloth was dried at 85°C for 3 minutes.

(Photosensitive liquid composition) Polymer compounds 1 to 6 10g Diazonium resins 1 to 4 1g Polyacrylic acid (Jurimar-Ac-1OL manufactured by Nippon Pure Chemical Industries, Ltd. 0.6g Victoria View Blue-BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.2 g2-Methoxyethanol 1.60 g The combinations of polymer compounds and diazo resins are shown in Table 1.

The obtained photosensitive planographic printing plate was heated with a 3 kHz ultra-high pressure mercury lamp.
After exposure for 30 seconds from a distance of oocm, development was performed at 25° C. for 45 seconds using the following developer to obtain a lithographic printing plate.

(Developer) Benzyl alcohol 50g Triethanolamine 15g Sodium sulfite
5g surfactant 5
0g water 1000
g The sensitivity and developability of these plates were investigated.

Regarding the developability, the above-mentioned developer was designated as developer-1, and it was replaced with developer-2 and -3 in equal amounts. Two times the amount of pure water was added and a diluted developer was used for development, and the developability of the non-image area was examined.

Furthermore, a printing durability test was conducted on a sheet-fed printing press using alkaline dampening water (pH = 10), and the number of printed sheets with poor inking or fading in the image area was calculated. Rigid strength.

These results are summarized in Table I.

From Examples 1 to 4 and Comparative Examples 1 to 2 below, it can be seen that the photosensitive lithographic printing plate of the present invention has excellent printing durability when using alkaline dampening water and excellent developability.

(Effects of the Invention) As explained in detail below, when the specific polymer compound of the present invention is used, planographic printing that has high printing durability and excellent developability in printing using alkaline dampening water can be achieved. This has the remarkable effect of making it possible to obtain separate editions.

Therefore, the present invention is extremely useful industrially.

Claims (1)

[Scope of Claims] A lithographic printing plate in which a photosensitive layer consisting of a diazonium resin and a polymer compound is provided on a grained and anodized aluminum plate, wherein the polymer compound is represented by the following general formula (I). A photosensitive lithographic printing plate characterized by containing the structural unit shown below. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a hydrogen atom, a halogen atom, or an alkyl group, and R_2 and R_3 are a hydrogen atom,
represents an alkyl group, R_4 represents an alkyl group or an alkoxy group, m represents an integer of 1 to 3, and n represents an integer of 0 to 4.
represents an integer, and Z represents -O- or -NH-. )