JPH02205849A - Positive type photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To widen the latitude of development and to improve the reproducibility of small dots and the plate wear by providing a photosensitive layer contg. a polymer selected from a specific vinyl polymer and polyaddition polymer on a base subjected to a surface treatment with the sol of a metal or metal oxide. CONSTITUTION:This printing plate has the photosensitive layer contg. at least one kind of the polymers selected from the vinyl polymer having an o- quinonediazide group and the polyaddition polymer having the o-quinonediazide group on the substrate formed by plating the surface of an iron sheet, then subjecting the sheet to the surface treatment with the sol of the metal or the metal oxide. This photosensitive planographic printing plate is produced by applying a photosensitive compsn. contg. the o-quinonediazide compd. on the iron base by using, for example, an org. solvent. The latitude of the development is widened in this way and the reproduction of the small dots is improved. In addition, the plate wear is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a positive-working photosensitive lithographic printing plate containing an 0-quinonediazide compound as a photosensitive component.

[Background of the invention]

O-quinonediazide compounds are conventionally known as photosensitive components used in photosensitive layers of positive-working photosensitive lithographic printing plates. For this type of photosensitive layer, a novolac type phenol resin is practically used in combination with the film-forming property, printing durability, etc.

A photosensitive composition containing a polyurethane resin having an 0-quinonediazide group has been developed as a technique intended to widen the range of appropriate development conditions and improve printing durability of a photosensitive lithographic printing plate having such a photosensitive layer. A technique of using a material as a photosensitive layer is disclosed in Japanese Patent Application Laid-Open No. 63-40254. However, although this technology has good stiffness resistance and over-development property, the reproducibility of small halftone dots is not sufficient, and there is also a problem with under-development property, so the range of appropriate development conditions (development latitude) is limited. The problem is that it's not enough.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a photosensitive lithographic printing plate that has a wide development latitude, good reproducibility of small halftone dots, and excellent printing durability.

[Structure of the invention]

The object of the present invention is to plate the surface of an iron plate and then apply O-
This is achieved by a photosensitive lithographic printing plate characterized by having a photosensitive layer containing at least one polymer selected from a vinyl polymer having a quinonediazide group and a polyaddition polymer having an 0-quinonediazide group.

The present invention will be explained in detail below.

The iron material for the iron plate used as the support for the photosensitive lithographic printing plate of the present invention includes pure iron as well as alloys of iron and other elements.

Other elements that form alloys with iron include carbon, manganese, and nickel. Examples of alloys include carbon steel (an alloy of carbon (0.04-1.7%) and iron), cast iron with a higher carbon content than carbon steel, and other elements (such as manganese, nickel, chromium, Examples include special steels containing (cobalt, tungsten, molybdenum) (for example, manganese steel, nickel steel, chromium steel, nickel-chromium steel). The above carbon steels include extremely mild steel (carbon 0.25% or less), soft* (0.25 to 0.5%), hard steel (carbon 0.5% or less),
~1.0%), extremely hard steel (carbon 1.0% or more).

In the present invention, the surface of the iron plate is preferably roughened. As the surface roughening method, various conventionally known methods can be used, such as mechanical methods, chemical methods, and electrolytic methods. Examples of the mechanical method include a ball polishing method, a brush polishing method, and a polishing method using liquid honing. Chemical methods include etching with a solution containing sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, oxalic acid, birophosphoric acid, ferric chloride, etc. The electrolytic method includes an electrolytic etching method and an electrolytic plating method.

The plating treatment in the present invention uses Ni, Cr, Cu, or Sn, which has a rust-preventing effect on iron materials. Note that the plating metal is not limited to the above-described single metal, but also includes an alloy containing one or more of these metals, or a composite plating of two or more of these metals.

After plating, chemical conversion treatment can be performed if necessary.

Chemical conversion treatment includes immersion in a solution containing chromate, dichromate, phosphate, molybdate, borate, perborate, etc., or electrolysis in the solution. .

The centerline average roughness (indicated in DIN 4768) of the support surface obtained by the above treatment is preferably 0.1 to 3 μm, more preferably 0.3 μm.
~15μ mouth.

The metal or metal oxide sol used after plating is a sol containing metal or metal oxide as a dispersant, and the surface treatment performed with this sol is hydrophilic treatment, and this treatment is performed on both the front and back surfaces of the support. There may be.

The sols of metals or metal oxides include water supplies, and the metals forming the dispersoids of the sol include, for example, A12°Ti,
Zr, Cr, Ni, Zn, Sn, Mn, C
u, Co, Fe, Pb.

There are Cd, Mg, Ca, etc., and in the present invention, at least one kind of sol of these metals or metal oxides is used. Among these metals, AQ, Cr, Ni and Z
n is preferred.

As a method for surface treatment with the above-mentioned sol, it is preferable to perform cathodic electrolysis or immersion treatment in a hydrosil containing the above-mentioned metal or metal oxide as a dispersoid.

The concentration of metal or metal oxide dispersoids in the hydrosil is preferably 1 to loOg/Q. Furthermore, in order to improve the stability of the sol in an aqueous solution, an inorganic salt such as chromic acid, phosphoric acid, or sulfuric acid, an organic acid such as citric acid or acetic acid, or a surfactant may be added to the treatment solution consisting of hydrosil. Can be added.

Although cathodic electrolysis conditions vary depending on the type of sol used, appropriate current density is 0.5 to IOA/dm2, treatment temperature is 5 to 50° C., and treatment time is 1 to 60 seconds.

The photosensitive planographic printing plate of the present invention can be produced by coating the photosensitive composition containing the O-quinonediazide compound on the iron support obtained as described above using, for example, an organic solvent.

Next, regarding the vinyl polymer and polyaddition polymer each having an 0-quinonediazide group (hereinafter also referred to as "ester compound of the present invention") contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention. explain.

The ester compound of the present invention is preferably a compound having an ester compound structure of a vinyl polymer having a phenolic hydroxyl group and an O-quinonediazide compound having an acid group.

The above-mentioned polymer having a phenolic hydroxyl group is a polymer having a unit having a phenolic hydroxyl group in its molecular structure, and has at least one unit represented by the following general formulas 1''l) to [4].
Polymers containing two structural units are preferred.

General formula (1) % formula % General formula [2] +CR+R2CRz→- COO-(-A 1B-OH General formula [3] -(-CR,R,-CR3→- -0H General formula [4] OH General formula In (1) to [4], R1 and R3 each represent a hydrogen atom, an alkyl group or a carboxyl group,
Preferably it is a hydrogen atom. R3 represents a hydrogen atom, an atom or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R4 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably an aryl group. A represents an alkylene group or alkyleneoxy group which may have a substituent and connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, and represents an integer of 1 o-io, and B has a substituent. represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent.

The above-mentioned vinyl polymer preferably has a copolymer-type structure, and examples of monomer units that can be used in combination with the structural units represented by the above general formulas [1] to [4] include, for example, ethylene, Ethylenically unsaturated olefins such as propylene, imbutylene, butadiene, inglene, etc., such as styrene, σ-methylstyrene,
Styrenes such as p-methylstyrene and p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride, such as methyl acrylate, acrylic ethyl acrylate, n-butyl acrylate, isobutyl acrylate, y-decyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as ethyl ethacrylate, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, p-chloroacrylanilide, I-nitroacrylanilide, Anilides such as m-methoxyacrylanilide, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether,
Vinyl ethers such as β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-I-methoxyethylene, 1
．． 1-dimethoxyethylene, ■, 2-dimethoxyethylene, 1. Ethylene derivatives such as 1-dimethoxycarbonylethylene and - There are vinyl monomers such as vinyl compounds. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, esters of aliphatic monocarboxylic acids and nitriles are preferred.

These monomers may be bound in the polymer of the present invention in either a block or random manner.

Next, typical examples of the ester compounds of the present invention will be given. In addition, in the following exemplified compounds, My is the weight average molecular weight, Q
:m:n or man is each structure (g) (i) CB.

('') (p) (Mw-20000゜Q: m: n = 30:30:40) (q) (w) H3 ('') Ny (s) Synthesizing the ester compound of the present invention as described above There are various methods for this. For example, there are methods that require α/β-unsaturated acid chlorides or α/β-unsaturated acid anhydrides and primary or secondary amines having a phenolic hydroxyl group. Accordingly, the reaction is carried out using a basic catalyst, and then the obtained monomer is homopolymerized according to a conventional method, or the monomer and at least one other vinyl monomer are copolymerized. By doing so, a polymer compound having a phenolic hydroxyl group is obtained, and then the resulting polymer compound is subjected to a condensation reaction with 0-7-toquinonediazide sulfonic acid chloride in the presence of an alkali in an organic solvent that is miscible with water. The ester compound of the present invention can be obtained by introducing a nitrogen 7-toquinonediazide sulfonyl group at the position of the phenolic hydroxyl group.

In the ester compound, the condensation rate (reaction rate % per 0'H group) of naphthoquinonediazide sulfonic acid chloride with respect to the phenolic hydroxyl group is preferably 15 to 80%, more preferably 20 to 50%. The condensation rate is calculated by determining the content of sulfur atoms in the sulfonyl group by elemental analysis.

The Mw is a value determined by CPC (gel permeation chromatography) or osmotic pressure method.

The amount of the ester compound of the present invention with the vinyl polymer in the photosensitive composition of the present invention is preferably 10 to 95% by weight, particularly preferably 40 to 90% by weight.

Preferred as the polyaddition polymer is a polyurethane resin. The ester compound of the polyaddition polymer and the O-quinonediazide compound in the present invention is preferably a diisocyanate compound represented by the following general formula [5] and the general formula [6] or (7)! It is a polyurethane resin whose basic skeleton is a reaction product with a diol compound having an O-quinonediazide group.

General formula [5] 0CN-R, -NGO General formula [6] General formula [7] In general formulas [5] to [7], R1 is a divalent aliphatic or aromatic which may have a substituent Indicates a group hydrocarbon group.

If necessary, R may contain other functional groups that do not react with isocyanate groups, such as ester, urethane, amide, ureido, and the like.

R1 represents a hydrogen atom, or an alkyl group, an aralkyl group, an aryl group, an alkoxy group, or an aryloxy group, each of which may have a substituent, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. Represents 6 to 15 aryl groups. R1, R4 and R6 may be the same or different, and each represents a single bond or a divalent aliphatic or aromatic hydrocarbon group which may have a substituent. Preferably an alkylene group having 1 to 20 carbon atoms, 6 to 1 carbon atoms
It represents five arylene groups, more preferably an alkylene group having 1 to 8 carbon atoms. Also, if necessary, R,,R.

Furthermore, R1 may contain other functional groups that do not react with isocyanate groups, such as ester, urethane, amide, ureido, and ether groups. Note that R3, R, %R6
and 2 or 3 of R1 may form a ring.

A" represents a tetravalent aromatic hydrocarbon which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

X represents 0 or N-R1.

R1 represents a hydrogen atom, or an alkyl group or an aryl group each of which may have a substituent, preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms and 6 to 15 carbon atoms.
represents an aryl group.

Note that R1 may form a ring together with one or two of R3, R1, R6, and R6.

D represents an 0-quinonediazide group which may have a substituent. It preferably represents an 0-naphthoquinonediazide group linked at the 4- or 5-position.

Specifically, the diisocyanate compound represented by the general formula [5] includes those shown below.

That is, 2,4-tolylene diisocyanate, a dimer of 2゜4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, I
-xylylene diisocyanate, 4゜4'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-
Aromatic diisocyanate compounds such as diisocyanate; aliphatic diisocyanate compounds such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, dimer acid diisocyanate, etc.; isophorone diisocyanate, 4゜4
′-Methylenebis (cyclohexyl isocyanate)
, methylcyclohexane-2,4 (or 2.6) diisocyanate, 1,3-(incyanatomethyl)cyclohexane, etc.;
Examples include diisocyanate compounds which are reaction products of diols and diisocyanates, such as adducts of 1 mol of 3-butylene glycol and 2 mols of tolylene diisocyanate.

Further, the diol compound having an O-quinonediazide group represented by the general formula [6] or [7] is preferably an O-quinonediazide compound having a halogenosulfonyl group,
It is an ester with a trihydroxy compound or an amide with a monoamino dihydroxy compound, and specifically includes the following.

That is, 2,6-bis(hydroxymethyl)-4-methylphenyl/1,2-naphthoquinone-2-diazide-5
-sulfonate, 3,5-dihydroxyphenyl/l,
2-naphthoquinone-2-diazide-5-sulfonate,
2.2-bis(hydroxymethyl)propyl/l, 2
-naphthoquinone-2-diazide-5-sulfonate, N
-(l,1-bis(hydroxymethyl)propyl)
-1,2-su7toquinone-2-diazide-5-sulfonamide, H-(3,5-dihydroxyphenyl)-1,
Examples include 2-naphthoquinone-2-diazide-5-sulfonamide.

The polyurethane resin of the present invention is a diisocyanate compound represented by general formula [5] and general formula [6] or [7].
It may be formed from two or more types of diol compounds having an 0-quinonediazide group shown in the following.

Furthermore, a diol compound which may have other substituents may be used in combination to an extent that the range of appropriate development conditions is narrowed.

Specifically, such diol compounds include those shown below.

Sochi, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glyco, -l, 1,3-butylene glycol, 1
．． 6-hexanediol, 2-butene-1,4-diol, 2,4-trimethyl-1,3-bentanediol,
1.4-bis-β-hydroxyethoxycyclohexane, cyclohexane dimetatool, tricyclodecane dimetatool, hydrogenated bisphenol A1 hydrogenated bisphenol F1 ethylene oxide adduct of bisphenol A,
Propylene oxide adduct of bisphenol A, ethylene oxide adduct of bisphenol F, propylene oxide adduct of bisphenol F, ethylene oxide adduct of hydrogenated bisphenol A, propylene oxide adduct of hydrogenated bisphenol A, hydroquinone dihydroxyethyl ether, p -xylylene glycol,
Dihydroxyethyl sulfone, bis-(2-hydroxyethyl)-2,4-)lylene dicarbamate, 2,4-
Drylene bis-(2-hydroxyethylcarbamide),
Bis-(2-hydroxyethyl)-■-xylylene carbamate, bis-(2-hydroxyethyl) terephthalate, 3.5-dihydroxybenzoic acid, 2゜2-bis
(Hydroxymethyl)propionic acid, 2゜2-bis (
2-hy(qxyethyl)propionic acid, 2,2-bis
(3-hydroxypropyl)probionic acid, bis(hydroxymethyl)acetic acid, bis(4-hydroxyphenyl)acetic acid, 4,4-bis(4-hydroxyphenyl)
Examples include pentanoic acid and tartaric acid.

The above-mentioned polyurethane resin having an 0-quinonediazide group is synthesized by heating the above-mentioned diisocyanate compound and diol compound in an aprotic solvent, adding a known catalyst having an activity corresponding to the reactivity of each compound. The molar ratio of the diisocyanate and diol compound used is preferably 0.8:1 to 1.2 to 1, and if incyanate groups remain at the end of the polymer, the final product can be treated with alcohols or amines, etc. It is synthesized in such a way that no incyanate group remains.

The molecular weight of the polyurethane resin of the present invention is preferably 1000 or more on weight average, more preferably 5000 to 5000.
It is in the range of 10 million.

Synthesis Example 1 f-IQ3 equipped with pH measuring device, dropping funnel, and stirrer
64.5 g of 1.2-su7toquinone-2-diazide-5-sulfonyl chloride (0,24
mol), 40.4 g (0.24 mol) of 2.6-bis (hydroxymethyl)-p-talesol, 44011 G of acetonitrile, and 17611 α of water were added, and the mixture was stirred at room temperature to disperse the solid. A mixture of 36.4 g (0.36 mol) of triethylamine and 80 ml (l) of acetonitrile was added dropwise to this mixture using a dropping funnel. At this time, the pn of the reaction mixture was adjusted to 5 to 6. The pH of the reaction mixture was 6. A mixture of triethylamine and acetonitrile was added dropwise until no change occurred in the vicinity. After the reaction was completed, the precipitate was filtered off, washed with water, and dried to give 32 g of 2,6-bis(hydroxymethyl)-4-
Methylphenyl-1,2-naphthoquinone-2-diazide-5-sulfonate was obtained. In addition, 2, 3 days round bottom flask of 50011112 equipped with a condenser stirrer.
14.0 g (0,035 mol) of 6-bis (hydroxymethyl)-4-methylphenyl-1,2-naphthoquinone-2-diazide-5-sulfonate and 5.9 g (0,035 mol) of hexamethylene diisocyanate were added. Dissolved in dioxane 40QtmQ. 0-25 g of di-n-butyltin dilaurate was added as a catalyst, and the mixture was heated to 50° C. for 3 hours with stirring. Thereafter, the reaction solution was poured into water 212 with stirring to precipitate a yellow polymer. This polymer was filtered and dried to obtain 16 g of polymer D).

The molecular weight was measured by gel permeation chromatography (CPC) and found to be 12,000 on a weight average basis (polystyrene standard).

Synthesis Examples 2 to 5 Ester compounds (u) to (X) of the present invention were synthesized according to Synthesis Example 1, except that the compounds shown in Table 1 below were used as diisocyanate compounds and diol compounds. All molecular weights are weight average (Polystyrene Table 1 The amount of polyurethane resin having 0-quinonediazide group in the photosensitive composition of the present invention is 2 to 80% by weight.
is preferable, and more preferably 20 to 40% by weight.

The photosensitive layer of the present invention contains 0 as a photosensitive component in the present invention.
- Only polymers with quinonediazide groups can be used, but are known. -It may be used together with a 7-toquinone diazide compound.

Known 0-naphthoquinonediazide compounds include those described in Japanese Patent Publication No. 43-28403, which are esters of 1,2-7toquinone-2-diazide-5=sulfonyl chloride and pyrogallol-acetone resin. is most preferred. Other suitable known orthoquinone diazide compounds include 1, which is described in U.S. Pat. Nos. 3,046,120 and 3,188,210;
There are esters of 2-naphthoquinone-2-diazido-5-sulfonyl chloride and phenol-formaldehyde resins. Other known O-naphthoquinone diazide compounds that can be used in the present invention include JP-A-47-5303, JP-A-48-63802, JP-A-48-63803;
Publications such as No. 48-96575, No. 38701-1970, No. 13354-1972, Japanese Patent Publication No. 11222-1970, No. 9610-1973, No. 17481-1971, U.S. Patent No. 2797213 , No. 3454400, No. 3544323, No. 357917, No. 3
No. 674495, No. 3785825, British Patent No. 1
No. 227602, No. 1251345, No. 1267
No. 005, No. 1329888, No. 1330932
Examples include those described in various specifications such as German Patent No. 854890 and German Patent No. 854890.

The amount of O-quinonediazide compounds in the photosensitive layer of the present invention is 5 to 80% by weight, more preferably 20 to 40% by weight, in total of the known compounds and the Q-quinonediazide group-containing polymer of the present invention.

The photosensitive layer of the present invention may further contain an alkali-soluble resin as a binder.

As an alkali-soluble tree host, JP-A-54-98613
A monomer having an aromatic hydroxyl group as described in the above publication, such as N-(4-hydroxy7enyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-1m-1 or p -Hydroxystyrene, 0
-1m"' or copolymer of p-hydroxyphenyl methacrylate and other monomers, US Pat. No. 4,123.
Examples include copolymers of hydroxyethyl acrylate or hydroxyethyl methacrylate and other monomers as described in No. 276. Other monomers to be combined include ethylenically unsaturated olefins, styrenes, acrylics, unsaturated aliphatic dicarboxylic acids, esters of α-methylene aliphatic monocarboxylic acids, nitriles, amides, and anilides. , vinyl esters, vinyl ethers, and N-vinyl compounds. Furthermore, novolac resins can also be used.

The novolac resin used as the alkali-soluble resin is obtained by copolycondensing at least one selected from phenol, m-cresol (or 0-cresol), and p-cresol with an aldehyde in the presence of an acidic catalyst. Examples of the aldehyde include aliphatic and aromatic aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, acrolein, and furfural.

Specific examples of novolak resins include phenol/formaldehyde resin, m-cresol/formaldehyde resin, 0-cresol/formaldehyde resin, phenol/cresol/formaldehyde copolycondensate resin, and m-cresol/formaldehyde resin.
-Cresol/p-cresol/formaldehyde copolycondensate resin, 0-cresol/p-cresol/formaldehyde copolycondensate resin, phenol'm-cresol bottle p described in JP-A-55-57841
Examples include -cresol φ formaldehyde copolycondensate resin, phenol/0-cresol/p-cresol/formaldehyde copolycondensate resin, and the like.

In addition, a polycondensation resin of polyhydroxyphenol and aldehyde can also be used. For example, JP-A-57
Resorcinol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/benzaldehyde resin described in JP-A-101833 and JP-A-57-101834, catechol/formaldehyde resin described in JP-A-59-86046, Examples include hydroquinone formaldehyde resin.

Among the above novolak resins, phenol/m-cresol p-cresol formaldehyde resin is preferred.

The content of the alkali-soluble resin in the photosensitive composition is preferably 30 to 95% by weight, more preferably 50 to 85% by weight based on the total solid content of the photosensitive composition.

In addition to the materials described above, the photosensitive layer of the present invention can also contain other additives as necessary. For example, various low-molecular compounds (e.g. phthalates, triphenyl phosphates, maleate esters) are used as plasticizers, and surfactants (e.g. fluorine surfactants, ethyl cellulose polyalkylene ether, etc.) are used as coating properties improvers. (nonionic activators, etc.), printout materials for forming visible images upon exposure to light, and the like. The printout material consists of a compound that generates acids or free radicals upon exposure to light and an organic dye that changes its color tone by interacting with it; such organic dyes include, for example, Victoria Pure Blue B.
OH [Toko Tsuchigaya Chemical 1, Oil Blue #603 [Orient Chemical J1 Patent Pure Blue [Manufactured by Juju Kingdom Chemical], Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosin B1 Basic Tsushin, Malachite Green, Oil Red, l -Cresol purple, rhodamine B1 auramine, 4-p-diethylaminophenyliminona 7-toquinone, cyano-p-diethylaminophenyl acetanilide, diphenylmethane, oxazine, xanthine, iminonaphthoquinone, azomethine and anthraquinone-based dyes.

Further, a sensitizer for improving sensitivity can also be included in the photosensitive layer of the present invention. As a sensitizer, US patent 4,
As described in No. 115,128, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-nindooxy-Δ4-tetrahydrophthalic anhydride, tetrachloroheptalic anhydride, maleic anhydride, chloro There are cyclic acid anhydrides such as maleic anhydride, α-phenylmaleic anhydride, W, hydrosuccinic acid, and pyromellitic acid.

1 to 15% by weight of these cyclic acid anhydrides in the total composition.
It can be included.

The positive-working photosensitive lithographic printing plate of the present invention can be formed by dissolving the photosensitive composition of the present invention in a solvent, coating the solution on the surface of a suitable support, and drying the solution. Examples of solvents that can be used include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, curtain coating, etc. can be used.

The positive-working photosensitive lithographic printing plate of the present invention can be used in the same manner as those conventionally used. For example, ultra-high pressure mercury lamps, metal halide lamps,
It is exposed to light using a light source such as a xenon lamp or a tungsten lamp, and then developed with an alkaline developer to form a positive-positive relief image in which only the unexposed portion of ζ remains on the surface of the support.

Examples of alkaline developers include sodium hydroxide,
Examples include aqueous solutions of alkali metal salts such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, sodium diphosphate, and sodium triphosphate.

Furthermore, an anionic surfactant, an amphoteric surfactant, and an organic solvent such as alcohol can be added to the developer as required.

〔Example〕

Preparation of Support 1 The surface of a steel plate with a thickness of 0 to 15 mm was roughened by etching with a Baume 40' ferric chloride solution, and the surface was roughened using a sulfate bath at a temperature of 50° C. and a current density of 5 A/ After plating with Zn to a thickness of 4 μm under the conditions of dm', 20 g/Q of Cr dispersoids with a particle size of 1100 nm were applied as the surface treatment of the present invention.

Electrolysis was performed in hydrosil containing 10 g/Q of phosphoric acid at a current density of 2 A/da' using a steel plate as a cathode for 30 seconds, washed with water, and dried to obtain Support-1.

Preparation of Photosensitive Planographic Printing Plate Sample-1 A photosensitive composition coating liquid (1) having the following composition was coated on the support-1 prepared as described above using a rotary coater to prepare a photosensitive planographic printing plate sample-1. It was set to 1.

Photosensitive composition coating liquid (1) Ester compound (a) of the present invention 1.5 g
Free radical generating compound (below) O, Ig Victoria Pure Blue BO)] (manufactured by Hode Tsuchiya Chemical Co., Ltd.) 0.07 g
Phenol novolac resin 5.0g Methyl cellosolve 1oOo! Preparation of Photosensitive Lithographic Printing Plate Sample-2 A photosensitive composition coating solution (2
) was coated in the same manner as photosensitive planographic printing plate sample-1 to prepare photosensitive planographic printing plate sample-2.

Photosensitive composition coating liquid (2) Ester compound (k) of the present invention 1.5 g
Free radical generating compound (below) 0.1g Victoria Pure Blue BOH (manufactured by Fukadogaya Chemical Co., Ltd.) (LO7g
Phenol novolac #l fat 5.0g Methyl cellosolve 100mff Preparation of photosensitive lithographic printing plate sample-3 A photosensitive composition coating solution (3
) was coated in the same manner as photosensitive planographic printing plate sample-I to prepare photosensitive planographic printing plate sample-3.

Photosensitive composition coating liquid (3) Ester compound (t) of the present invention 1.5 g
Free radical generating compound (below) 0.1g Victoria Pure Blue BOH (manufactured by Fukadogaya Chemical Co., Ltd.) 0.07g
Phenol novolac tree IN 5g Methyl cellosolve 5.0g Preparation of free radical generating compound support-2 An aluminum plate (material 1050, tempered H16) with a thickness of 0.24 mm was dissolved in a 5% by weight sodium hydroxide aqueous solution.
After degreasing for 1 minute at 0°C, the temperature was 25°C and the current density was 60^ in a 0.5M aqueous solution of lQ hydrochloric acid.
/ d m ”% Treatment time: Electrolytic etching treatment was performed under the conditions of 30 seconds.Next, after performing a desmut treatment for 10 seconds at 60° in a 5% by weight sodium hydroxide aqueous solution, 20% by weight sulfuric acid was applied. Anodizing treatment was performed in a solution at a temperature of 20°C, a current density of 3 A/dm', and a treatment time of 1 minute.Furthermore, a hot water sealing treatment was performed with hot water at 30°C for 20 seconds. , an aluminum plate for use as a support for a lithographic printing plate was produced.

Each of the above (
The photosensitive composition coating solutions of 1) to (3) were applied using a spin coater and dried at 90° C. for 4 minutes to obtain photosensitive lithographic printing plate samples 4 to 6.

For the photosensitive lithographic printing plates-1 to 6 produced as described above, over-developability, under-developability, dot reproducibility, and printing durability were measured. The results are shown in Table 2.

(Note) l) Dilution ratio of developer 5DR-1 (manufactured by Konica Corporation) ×
4.5, it is expressed as the difference in the number of solid steps between development at 27°C for 20 seconds and standard development (development at 27°C for 20 seconds at dilution ratio x6).

2) Shown as the dilution ratio of the developer just before it starts to stain when developed with 5DR-1 at 27°C for 20 seconds.

3) Indicated by the minimum reproducible halftone dot area ratio on the original film.

Table 1 shows that the photosensitive lithographic printing plate according to the present invention has excellent development latitude and reproducibility of small halftone dots, and has the same printing durability as those using a conventional aluminum plate as a support. It turns out it's more than that.

〔Effect of the invention〕

According to the present invention, a photosensitive lithographic printing plate having a wide development latitude, good reproducibility of small halftone dots, and excellent printing durability can be obtained.

Claims (1)

[Claims] After plating the surface of the iron plate, at least one kind selected from a vinyl polymer having an o-quinone diazide group and a polyaddition polymer having an o-quinone diazide group on a support surface treated with a metal or metal oxide sol. A photosensitive lithographic printing plate characterized by having a photosensitive layer containing a polymer.