JPH01297643A - Production of planographic printing plate - Google Patents

Abstract

PURPOSE:To reduce a water consumption, and to prevent the generation of a pollution caused by a waste water and the reduction of the development ability of a developer by incorporating a prescribed amount of a polyurethane resin having a substituting group contg. an acidic hydrogen atom, in a photosensitive composition constituting of a photosensitive layer. CONSTITUTION:The photosensitive planographic printing plate is image-wisely exposed and then is processed with an aqueous alkaline developer and immediately after with a desensitizer without using a washing step. And >=50wt.% of the polyurethane resin having the substituting group contg. the acidic hydrogen atom is incorporated in the photosensitive layer of the printing plate. Accordingly, the printing plate is processed with the desensitizer immediately after developing it, without using the washing step. Thus, the water consumption is reduced, and the production of the waste water is reduced, and the fear of generating the pollution is reduced, and the development processing of the printing plate without generating a sludge, a greasing and a faulty forming makes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a lithographic printing plate from a photosensitive lithographic printing plate (hereinafter referred to as a PS plate).

[Conventional technology]

When the PS plate on which the original has been printed is developed by an automatic processor, a developer is applied while being conveyed to a developer tank, and the plate is rubbed with a brush, sponge, etc. for development processing. Since photocuring does not occur in the non-image area on the PS plate on which the original is printed, this area becomes a swollen film by development containing an organic solvent or an alkaline aqueous solution in the development process. The non-image area, which has become a swollen film, is easily removed by rubbing means such as a brush or sponge, leaving only the image area.

Therefore, the developer is contaminated with eluates such as photosensitive substances from the 28th plate. Further, since the developer is normally applied to the PS plate passing through the developer tank in a single shower, deterioration due to air, such as a drop in pH due to carbon dioxide entering the melt, occurs.

Therefore, when the developing ability of the developer decreases due to the processing amount of the PS plate and the passage of time and reaches its limit, it is replaced with a new developer.

If you process the PS version beyond the limits of this processing power, the PS
The photoresist film in the non-image area remains on the surface of the plate, which causes stains during printing and makes printing performance such as tone reproduction unstable.

Additionally, in the past, developing solutions were washed with large amounts of water and then desensitized, but using large amounts of washing water not only increases costs, but also leads to the depletion of water resources. Therefore, it is desirable to reduce the amount of water used as much as possible.In addition, environmental pollution has become a problem worldwide in recent years, and it is desirable to avoid producing wastewater during the development process of printing plates. For example, Japanese Patent Application Laid-Open No. 54-8002 proposes a method in which a fat-free treatment is performed immediately after development without washing with water.

However, when performing the above-mentioned waterless washing process, even when processed with a developing solution near the limit within the range of the above-mentioned processing capacity limits, background smudges and poor inking may occur on the plate, and photosensitivity A tired developer with dissolved substances is PS.
It adheres to the plate and mixes with the gum liquid, resulting in the formation of precipitates, scumming on the plate, and poor inking. This problem can be solved by replacing the developer when there is still a small amount of eluted photosensitive material, but this is uneconomical.

[Problem to be solved by the invention]

The purpose of the present invention is to reduce the amount of water used, eliminate the risk of pollution caused by wastewater, prevent the development ability of the developer from decreasing even when the amount of PS plates processed increases, and reduce the amount of water used in the development process. Even if the photosensitive substances contained in the developer adhering to the PS plate are brought into the desensitizing process, the above-mentioned problems are unlikely to occur, so the developer and desensitizing agent can be used economically. It is an object of the present invention to provide a method for producing a lithographic printing plate from a photosensitive lithographic printing plate.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the present inventors discovered that this object could be achieved by using a specific composition as a photosensitive composition for the photosensitive layer of a PS plate, and arrived at the present invention. did.

That is, the present invention provides a method for producing a lithographic printing plate by imagewise exposing a photosensitive lithographic printing plate, treating it with an aqueous alkaline developer, and immediately treating it with a desensitizing agent without going through a water washing step. This is a method for producing a lithographic printing plate, characterized in that the photosensitive composition forming the photosensitive layer of the photosensitive lithographic printing plate contains 50% by weight or more of a polyurethane resin having a substituent having an acidic hydrogen atom.

In the conventional method, after development with an alkaline developer, a minute amount of alkaline aqueous solution adhering to the lithographic printing plate is removed by washing with water, and the non-image area becomes water-friendly. We are treating it with a desensitizing agent to make it more resistant to fat.

Various methods are used for treatment with desensitizing agents, but the most common method among conventional methods and the method of the present invention is a method of adsorbing hydrophilic colloids to strengthen the hydrophilicity of the surface. Specifically, hydrophilic colloids such as gum arabic, carboxymethylcellulose (CMC), and methylcellulose are used, and if necessary, a desensitizer made by adding acid to these colloids is applied to desensitize the non-print areas. A method is used to

By the way, when development is carried out by hand development or the like, even if the photosensitive substance contained in the developer adhering to the PS plate gets mixed into the desensitizing solution, it does not pose a big problem. However, if an automatic developing machine is used to continuously perform fat-free treatment immediately after development without going through the water washing process, will it be carried in due to adhesion? Accumulation of XX amount of photosensitive material will cause sludge to form in the desensitizing solution, poor inking and scumming, making it necessary to use a new desensitizing agent. .

In order to extend the life of such desensitizers, it is necessary to reduce the amount of developer carried into the desensitizer by the developed plate. For that purpose, it is advantageous to interpose a squeeze step between the development step and the fat-unfavorable step.

In this squeezing step, the effect is greater when rollers with low hardness and good surface properties are used facing each other and the nip pressure is increased (the effect is greater when a plurality of pairs of rollers are used).

The photosensitive composition forming the photosensitive layer of the PS plate that is developed as described above contains 50 weight percent or more of a polyurethane resin having a substituent having an acidic hydrogen atom. This dramatically improves the development processing capacity, making it possible to use the developer economically and reducing the amount of photosensitive substances contained in the developer that adheres to the PS plate that comes out of the development process. However, since the above-mentioned problems are less likely to occur, anti-greasy liquids, that is, gum liquids can be used economically.

In the present invention, the substituent having an acidic hydrogen atom refers to a substituent whose acid dissociation constant (pKa) in water is 7 or less, such as -COOH, -So□NHCOO-1CON
H3(h-1-C0NI(So□NH-1-NIICO
Includes NH3O□-, etc. Particularly suitable is -CO
It's OH.

The acid content per tg of the resin is preferably 0.05 to 6 milliequivalents. If it is less than 0.05 milliequivalent, developability with an alkaline developer will be insufficient, and if it is more than 6 milliequivalent, abrasion resistance will deteriorate. Preferably it is 0.2 to 4 milliequivalents.

Polyurethane resins suitably used in the present invention include diisocyanate compounds represented by the following general formula (1), and diol compounds having carboxyl groups represented by general formulas (11), (t[I), or (IV)]. Examples include polyurethane resins whose basic skeleton is the reaction product of

0CN-R' -NCO (1) t 1O-R3-C-R'-OH (II) S 0OH IO-R3-Ar -R' -OH (III) S 0OH 110-R3-N-R'-OR (IV,)S COOH where R1 is a substituent (e.g. alkyl, alkenyl,
Aralkyl, aryl, alkoxy, and halogeno groups are preferred. ) represents a divalent aliphatic or aromatic hydrocarbon that may have. If necessary, R1 may contain other functional groups that do not react with isocyanate groups, such as ester, urethane, amide, ureido groups, and carbon-carbon unsaturated bonds.

R1 is a hydrogen atom, an alkyl, alkenyl, aralkyl, aryl, alkoxy, R1 that may have a substituent (for example, alkyl, aryl, alkoxy, ester, urethane, amide, ureido, and halogeno groups are preferred); R represents a monoloxy group, preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an aryl group having 6 to 15 carbon atoms. R3, R
4, R5 may be the same or different, and may have a single bond or a substituent (for example, alkyl, alkenyl, aralkyl, alkyl, alkoxy, and halogeno groups are preferred). Indicates a good divalent aliphatic or aromatic hydrocarbon. Preferably, it represents an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, and more preferably an alkylene group having 1 to 8 carbon atoms, and if necessary,
R3, R', and R' may contain other functional groups that do not react with isocyanate groups, such as ester, urethane, amide, ureido groups, and carbon-carbon unsaturated bonds. Note that two or three of R2, R3, R4, and R5 may form a ring.

Ar represents a trivalent aromatic hydrocarbon which may have a substituent, preferably an aromatic group having 6 to 15 carbon atoms.

Specifically, the diisocyanate compound represented by the general formula (I) includes those shown below.

That is, 2,4-tolylene diisocyanate, a dimer of 2゜4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m
-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),
Alicyclic diisocyanate compounds such as methylcyclohexane-2,4 (or 2.6) diisocyanate, 1°3-(isocyanatomethyl)cyclohexane, etc.; 1,3
Examples include diisocyanate compounds which are reaction products of diols and diisocyanates, such as adducts of 1 mol of butylene glycol and 2 mols of tolylene diisocyanate.

Further, the diol compound having a carboxyl group represented by the general formula (n), (I[[) or (IV)] specifically includes those shown below.

That is, 3,5-dihydroxybenzoic acid, 2,2-bis(
hydroxymethyl)propionic acid, 2゜2-bis(2-
hydroxyethyl)propionic acid, 2,2-bis(3-
hydroxypropyl)propionic acid, bis(hydroxymethyl)acetic acid, bis(4-hydroxyphenyl)acetic acid,
Examples include 4.4-bis(4-hydroxyethyl)pentanoic acid, tartaric acid, N,N-bis(2-hydroxyethyl)-3-carboxy-propionamide, and the like.

In addition, as the polyurethane resin of the present invention having an acidic hydrogen atom other than a carboxyl group, the diisocyanate compound of the -i formula (1) and the following general formulas (V), (Vl), (
It includes polyurethane resins whose basic skeleton is a structure represented by the reaction product of (2) or (2) with a diol compound.

)10-1? "-C-1?'-OH(V)■ S IO-R'-Ar -R'-OH(Vl)S Summer R6, )10-R"-N-R'-OH(■) 110-R '-Y-R'-OR (■) In the formula, R1, R3, R4, R5 and Ar have the same meanings as above. R& represents a substituent (e.g., alkyl, alkoxy,
Preferred are halogeno groups. ), preferably alkyl having 1 to 20 carbon atoms or alkenyl having 2 to 20 carbon atoms, aryl having 6 to 15 carbon atoms, An aralkyl group having 7 to 15 carbon atoms, more preferably alkyl having 1 to 8 carbon atoms, or alkenyl having 2 to 8 carbon atoms, and 6 carbon atoms.
~10 aryl groups are shown.

Y is an N-sulfonylamide group (C0-N1l-3Oz
), N-sulfonylureido group (-NH-CO-NH
SO2), N-aminosulfonylamide group (C0-NH
-5Ox-Nl (-) or sulfonylurethane group (-0
-CO-Nll-3Ot-).

Further, diol compounds represented by the general formula (V), (Vl), (■), or (■) are, for example, general formulas (■), (I[
After protecting the hydroxy group of the diol compound having a carboxyl group represented by I) and (IV), in the presence of a base,
General formula (IX), (X) , (XI) or (X n )
It is synthesized by reaction with a compound of After further reaction with chlorosulfonyl isocyanate, the general formula (X I[
It is synthesized by reacting with the amine compound [).

R' Sow NCO(IX) X-R3-GO-N)l-5(h-R'
(X)X R3Ni1 Co NH-Sow
R'(XI)X R'CoNH-
3Oz Nll R6(Xll)R' N)Iz
(XI[I) In the formula, X represents a chlorine atom or a bromine atom.

Further, in the case of a sulfonylurethane group, it can be synthesized by reacting one hydroxy group of a trihydroxy compound with a compound of general formula (IX).

However, the compound of general formula (X), for example, the following general formula (
Reaction of the compounds of the general formula (XIV) and (XV), the reaction of the compound of the general formula (ON) with the following general formula (XVI) (!: (XV)), the reaction of the compound of the general formula (XII) After reaction of (X■) with chlorosulfonyl isocyanate, each is synthesized by reaction with an amine compound of general formula (XI[[).

X-R'-COCj! (XIV
)R'-5(h-N11z (
XV)X-! ? '-NCO(XVT) X-R'-C00II
(X■) Furthermore, the diol compound represented by the general formula (■) is, for example, the general formula (XrV) and the following general formula (
After the reaction of the compound of the general formula (X
) are synthesized by hydroxylating the respective obtained compounds.

X R' SOx MHz
(X■)X-R' NHz
(XIX) Specifically, general formulas (II), (III),
The diol compounds represented by (rV) and (V) include those shown below.

8O-CHz-C-CHt-OH ■ CoCo-Ni1-5OzC J 隘4) (NU5) C11゜(NllL8)
) +1O−CIl□CI(z −N −C)I zGHz
-OH joy (patient 16) 1 (0-CHtCHt-N-CH□CH2-OHC=0 CH2CH2-Co-NH-SO□-NH-CzHsf
lo-CHz-C-CHz-ON COO-CHzCO-NH-3ow-NH-CtHs(
11h19) IO-CHzCoo-CHzCO-NH-3oC=0 ■ CHiCIIt-COO-CHzCO-NH-3(h-
NH-Ct)Is(隘20) CH.

(21) Hs (N122) HO-CHiCO-NH-3 (h
-CJb-011 (23) 1 (0-CHzC
O-NH-SO2-NH-CJa-OH (Nu24)
8O-CsHiCO-111-3Ox-N)I-C
J*-OH The polyurethane resin used in the present invention is composed of a diisocyanate compound of formula (1) -a and general formula (Vl), (
(■) or (■) to a polyurethane resin having a carboxyl group, which is a reaction product with a diol compound, in the presence of a base, the general formula (IX), (X), (XI) or (X I
[) After reacting the compound of the general formula (X
It can also be synthesized by reacting an amine compound of I[I 2 ).

Furthermore, a diol compound that does not have a carboxyl group and may have other substituents that do not react with isocyanate may be used in combination to the extent that the alkali developability is not reduced.

Specifically, such diol compounds include those shown below.

That is, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1.3-butylene glycol, 1.
4-butanediol, 1,5-bentanediol, 1,
6-hexanediol, 2-butene-1,4-diol, 2-butyne-1,4-diol, 2,2,4-trimethyl-1,3-bentanediol, 2,2-diethyl-
1,3-propanediol, 1,4-bis-β-hydroxyethoxycyclohexane, cyclohexanediol, cyclohexane dimetatool, tricyclodecane dimetatool, hydrogenated bisphenol A, diethyl 2,2-dimethylolmalonate, bis +2-hydroxyethyl) sulfide, hydrogenated bisphenol F, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol, ethylene oxide adduct of bisphenol F, propylene oxide adduct of bisphenol F, ethylene of hydrogenated bisphenol A oxide adduct, propylene oxide adduct of hydrogenated bisphenol A, hydroquinone dihydroxyethyl ether,
p-xylylene glycol, dihydroxyethyl sulfone, bis(2-hydroxyethyl)-2,4-tolylene dicarbamate, 2,4-tolylene-bis(2-hydroxyethylcarbamide), bis(2-hydroxyethyl)-m -xylylene dicarbamate, bis(2-hydroxyethyl) isophthalate, and the like.

Furthermore, a substituent -5O□NHCOO- having an acidic hydrogen atom can be introduced into the polyurethane resin of the present invention by reacting the remaining 10H groups with the compound of general formula (IX).

The polyurethane resin of the present invention is prepared by mixing the above-mentioned diisocyanate compound and diol compound in an aprotic solvent using a known catalyst having an activity depending on the reactivity of each, such as diethylaniline, 2.2.2-diazabicyclooctane, n-
It is synthesized by adding dibutyltin dilaurate etc. and heating. The molar ratio of diisocyanate and diol compound used is preferably 0.8:1 to 1.
If the ratio is 2:1 and an isocyanate group remains at the end of the polymer, the polymer can be finally synthesized in a form in which no isocyanate group remains by treating with an alcohol or an amine.

The molecular weight of the polyurethane resin of the present invention is preferably 1000 or more on weight average, more preferably s, ooo
~150,000.

These polyurethane resins may be used alone or in combination, and the content of these polyurethane resins contained in the photosensitive composition is 50% by weight or more, preferably 5% by weight or more.
0-95% by weight, more preferably about 60-90% by weight
It is.

As the basic composition of the photosensitive composition of the present invention, the polyurethane resin can be used alone, but preferably a combination of the compositions shown below is used. That is, +11 combination system of the polyurethane resin of the present invention and a photopolymerization initiator and/or sensitizer, (2) combination system of the polyurethane resin of the present invention and a diazonium compound, (3) polymerization with the polyurethane resin of the present invention A combination system of a monomer or oligomer having at least two possible ethylenically unsaturated groups and a photopolymerization initiator and/or a sensitizer; (4) a polyurethane resin of the present invention and a photopolymerization initiator and/or a sensitizer;
or a combination system of a sensitizer and a diazonium compound, (5) a monomer or oligomer having at least two ethylenically unsaturated groups polymerizable with the polyurethane resin of the present invention, a photopolymerization initiator and/or aggravating agent, and a diazonium compound Used in combination with

The system (2) is particularly preferred. (When used in system 11, it is necessary to introduce carbon-carbon unsaturated bonds into the polyurethane resin.

The photosensitive composition of the present invention may also contain other resins in an amount of 50% by weight or less based on the polyurethane resin. Examples of resins to be mixed include polyamide resin,
Examples include epoxy resins, polyacetal resins, acrylic resins, methacrylic resins, polystyrene resins, and novolac type phenolic resins.

When diazonium compounds are used in combination, the diazonium compounds used in the present invention include US Pat.
Examples include the diazonium compounds described in No. 67.147 and the diazonium compounds described in U.S. Pat. Diazo resins such as those represented by the following are useful. Preferred diazo resins include, for example, hexafluorophosphates and tetrafluorophosphates of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde. Also, sulfonic acid salts of condensates of p-diazodiphenylamine and formaldehyde as described in U.S. Pat. No. 3,300,309 (for example,
p-) luenesulfonate, dodecylbenzenesulfonate, 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate, etc.), phosphinate (e.g. benzenephosphinate, etc.), hydroxy group-containing 5
Compound salts (for example, 2,4-dihydroxybenzophenone salt, etc.), organic carboxylic acid salts, and the like are also preferred.

Furthermore, 3-methoxy-4-diazo-diphenylamine as shown in JP-A No. 58-27141 is added to 4,4
Mesitylene sulfonate obtained by condensation with '-bis-methoxy-methyl-diphenyl ether is also suitable.

The content of these diazonium compounds in the photosensitive composition is 1 to 50% by weight, preferably 3 to 20% by weight.

Moreover, two or more types of diazonium compounds may be used in combination, if necessary.

Various additives can be further added to the photosensitive composition used in the present invention.

For example, alkyl ethers (e.g. ethyl cellulose, methyl cellulose) to improve coating properties, surfactants (e.g. fluorosurfactants), membrane flexibility,
Plasticizers to impart abrasion resistance (e.g. tricresyl phosphate, dimethyl phthalate, dibutyl phthalate, trioctyl phosphate, tributyl phosphate, tributyl citrate, polyethylene glycol, polypropylene glycol, etc.), making the image area of the developer visible Pigments such as acridine dyes, cyanine dyes, styryl dyes, triphenylmethane dyes, and phthalocyanines are used as coloring substances for image formation, as well as other common stabilizers for diazo resins (phosphoric acid, phosphorous acid, pyrophosphoric acid, oxalic acid). , boric acid, p-toluenesulfonic acid, benzenesulfonic acid, p-hydroxybenzenesulfonic acid, 2-methoxy-4-hydro-5-benzoylbenzenesulfonic acid, malic acid, tartaric acid, dipicolinic acid, polyacrylic acid acids and their copolymers;
Polyvinylphosphonic acid and its copolymer, polyvinylsulfonic acid and its copolymer, 5-nitronaphthalene-1
-phosphonic acid, 4-chlorophenoxymethylphosphonic acid, sodium phenyl-methyl-pyrazolone sulfonate, 2-phosphonobutanetricarboxylic acid-1,2,4,
1-phosphonoethanetricarboxylic acid-1,2,2,1-
hydroxyethane-1,1-disulfonic acid, etc.) can be added. The amount of these additives added varies depending on the purpose for which they are used, but is generally 0.5 to 30% by weight based on the total solid content of the photosensitive layer.

The photosensitive composition of the present invention is dissolved in a suitable organic solvent and coated on a support having a hydrophilic surface at a dry coating weight of 0.5 to 5.
g/n? 28 plates can be obtained. The concentration of the photosensitive composition during application is 1 to 50% by weight.
It is desirable that the range be within the range of . The coating solvent used is methyl cellosolve, ethyl cellosolve, 1-methoxy-2-propatol, methyl cellosolve acetate,
Examples include acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethyl sulfoxide, ethylene dichloride, methyl lactate, ethyl lactate, cyclohexanone, dioxane, and tetrahydrofuran. A mixed solvent of these or a mixed solvent obtained by adding a small amount of water or a solvent such as toluene that does not dissolve the diazo resin or the polymer compound to these solvents or mixed solvents is also suitable. When applying and drying a photosensitive solution obtained by dissolving a photosensitive composition in these solvents, it is desirable to dry at 50-120°C. The drying method may be performed by starting at a low temperature (pre-drying and then drying at a high temperature), or by selecting an appropriate solvent and concentration, it may be directly dried at a high temperature.

As the support having a hydrophilic surface on which the photosensitive composition of the present invention is applied, an aluminum plate that has been subjected to a hydrophilic treatment is particularly preferable. Mechanical methods such as wire brush graining, brush graining in which the surface is roughened with a nylon brush while pouring slurry of abrasive particles, ball graining, and chemical graining in which the surface of the aluminum plate is made using HF, AlIC1s, or HCl as an etchant are used. After the surface is grained by electrolytic graining using nitric acid or hydrochloric acid as an electrolyte, or by composite graining which is a combination of these surface roughening methods, the surface is etched with acid or alkali as necessary, and then etched. Preferably, the aluminum is anodized in sulfuric acid, phosphoric acid, oxalic acid, boric acid, chromic acid, sulfamic acid, or a mixed acid thereof using a direct current or alternating current power source to form a strong passive film on the aluminum surface. Such a passive film itself makes the aluminum surface hydrophilic, but if necessary, silicate treatment (sodium silicate, silicate, etc.) as described in US Pat. No. 2,714,066 and US Pat. potassium fluorozirconate treatment as described in US Pat. No. 2,946,638; phosphomolybdate treatment as described in US Pat. No. 3,201,247; alkyl as described in UK Patent No. 1,108,559 Titanate treatment, polyacrylic acid treatment described in German Patent No. 1091433, German Patent No. 1134093
The polyvinylphosphonic acid treatment described in the patent specification and British Patent No. 1230447, Japanese Patent Publication No. 44-640
Phosphonic acid treatment described in Publication No. 9, U.S. Patent No. 3
Phytic acid treatment described in No. 307951, JP-A-58-16893 and JP-A-58-18291
A composite treatment using a hydrophilic organic polymer compound and a divalent metal described in the publications of JP-A-59-10165
Particularly preferred are those which have been subjected to a hydrophilic treatment by undercoating with a water-soluble polymer having a sulfonic acid group as described in Publication No. 1. Other hydrophilic treatment methods include U.S. Patent No. 36
Mention may also be made of the silicate electrodeposition described in No. 58662.

A PS plate having a photosensitive layer coated on a support having a hydrophilic surface can be developed with a developer containing weakly alkaline water after image exposure to obtain a negative relief image of the original image. Light sources suitable for exposure include carbon arc lamps,
Examples include mercury lamps, xenon lamps, metal halide lamps, strobes, and ultraviolet laser beams. As a developing solution for a PS plate having a photosensitive layer according to the present invention, JP-A-51-77
No. 401, JP-A-51-80228, JP-A-53-4
Organic solvents (benzyl alcohol, ethylene glycol monophenyl ether, etc.), alkalis (triethanol, amines, monoethanolamine, etc.), anionic surfactants (aromatic sulfonates, dialkyl sulfosuccinates, alkylnaphthalene sulfonates, branched alkyl sulfate salts, etc.), water and, if necessary, antifouling agents (sodium sulfite, sulfopyrazolone, etc.). water softeners (e.g., sodium salt of ethylenediaminetetraacetic acid) and water softeners (e.g., sodium salt of ethylenediaminetetraacetic acid).

A weakly alkaline aqueous solution can be given as follows.

The developed PS plate is immediately desensitized without being washed with water. The desensitizing liquid used in this desensitizing treatment includes Japanese Patent Publications Nos. 61-45553 and 62-16.
Those described in No. 834 and No. 62-25118 are preferred.

〔Effect of the invention〕

In the present invention, desensitization treatment is performed immediately after development without passing through a water washing step. Therefore, it is possible to reduce the amount of water resources used, thereby reducing the amount of waste water generated, and thus eliminating the risk of pollution. In addition, since a predetermined amount of a specific polyurethane resin is used, the developing ability of the developer does not decrease even when the amount of PS plates processed increases, and the amount of polyurethane resin that adheres to the PS plate that comes out of the development process does not deteriorate. Even if a photosensitive material is brought into the desensitizing process, it can be developed without producing sludge, background smearing, or poor inkling, making it possible to use less developing solution and desensitizing agent. and can significantly improve the quality of the processed PS version.

, Hereinafter, the present invention will be explained in more detail based on examples.

Example 1 and Comparative Example 1 The surface of a JIS 1050A aluminum plate having a thickness of 0.3 as was grained using a nylon brush and a 400 mesh pumice stone washing suspension, and then thoroughly washed with water. This was added to a 10% aqueous sodium hydroxide solution at 70℃ for 6 hours.
After immersing the ring for 0 seconds and etching, rinse with running water,
After neutralizing and cleaning with 1% nitric acid, the surface was roughened at 160 corons/dm'' in a 1% nitric acid aqueous solution using the electrochemical roughening method described in JP-A-53-67507, that is, using a sinusoidal alternating current waveform. Electrolytic surface roughening treatment was performed using a special amount of electricity at the anode.Continued 30
% sulfuric acid aqueous solution and desmutted for 2 minutes at 55° C., and then anodized in a 7% sulfuric acid aqueous solution to a thickness of 2.0 g/rrf. After that, JISa at 70℃
Immersed in a 3% aqueous solution of sodium silicate for 1 minute,
Washed with water and dried. The following photosensitive solution was applied to the aluminum plate obtained as described above using a wheeler and dried at 80° C. for 2 minutes. The coating weight was 2.0 g/rrl. One photosensitive solution was 5 g of 4-(n-dodecyl)benzenesulfonate polymer (al), a condensate of 4-diazodiphenylamine and 0.8 g formaldehyde.
Malic acid 0.1gFC
430 (Fluorine interface manufactured by 3M, USA 0.02
g activator) Victoria Pure Blue BOH0,1g2-methoxyethanol 100gHowever, polymer (
al is the synthesis example (10
) is a polyurethane resin having carboxyl groups synthesized in the same manner as . That is, as a diisocyanate, 4
．． Polyurethane synthesized from 4'-diphenylmethane diisocyanate using a 60:40 molar mixture of 2,2-bis(hydroxymethyl)propionic acid and 1,3-propanediol as the diol (formed metal t: 1.58 meq/g) It is. In the same way, PS is used which differs only in that it contains polymer (bl instead of al).
A plate was prepared and designated as Comparative Example 1. However, the polymer Tbl is N-(-4-hydroxyphenyl)methacrylamide/
It is a copolymer of acrylonitrile/ethyl acrylate/methacrylic acid (molar ratio 10/40/40/10).

These PS plates were subjected to image exposure for 1 minute from a distance of 1 m using a PS light manufactured by Fuji Photo Film Co., Ltd., and developed and gummed at 25° C. for 50 seconds using a waterless automatic developing machine 800EBI manufactured by Fuji Photo Film Co., Ltd. The developer is an aqueous alkaline developer DN-3C manufactured by Fuji Photo Film Co., Ltd. with a volume ratio of 1:2 (water).
After diluting the gum solution, the volume ratio of FN-2 manufactured by the same company was 1:l (
A diluted solution of water) was used.

As a result of this treatment, the polymer (P using Al)
The S version uses developer 17! PS version processing amount per unit is 12rrr/
Up to ff, there were no development defects or sludge caused by eluates from the PS plate brought into the processing solution in the gum coating tank, and no stains or inking defects were observed in printing performance. P with polymer (bl)
The S version has a throughput of 4 hours! When it reached this point, some development defects occurred, and background smudges also occurred in printing.

Examples 2 to 4 and Comparative Example 2 JP-A-62-123 was prepared in the same manner as in Example 1 except that the following polymer was used instead of the polymer of Example 1 (al).
Synthesis examples (11) and (12) of 452 and JP-A-62-1
A PS plate was made using the polymer of Synthesis Example (9) of 23453.

Synthesis examples (11) and (12) of JP-A-62-123452
) Polyurethanes (K) and (L) were synthesized using the following diisocyanates and diols.

Synthesis Example (9) of JP-A-62-123453 is polyurethane (1) synthesized from the following diisocyanate and diol (acid content: 1.20 meq/g).

These PS plates and the PS plate using the polymer (bl) prepared in Example 1 were placed in an automatic processor using Fuji Photo Film Co., Ltd. 2.
Bath development Using a waterless washing type automatic developing machine 800H, the dilution of the developer was 1:1 (water), and the development conditions were 30°C for the first bath.
When tested in the same manner as in Example 1 except that the second bath was at 25°C for 20 seconds, all three types of PS plates could be processed at a rate of 25 rrr/1 or more.
PS plate using polymer (BL has a throughput of 10 m/j?
When it reached this point, poor development, background smudges, and poor inking occurred.

Procedural amendment written by the Commissioner of the Japan Patent Office on 1983/27, Yoshi 1) Tsuyoshi Bun Tonohyo 1, Indication of the case 1988 Patent Application No. 129197 2, Title of the invention Method for manufacturing lithographic printing plates 3, Amendments to be made Relationship with the patent case Applicant name (520) Fuji Photo Film Co., Ltd. 4, Agent 5, Date of amendment order Voluntary 6, Subject of amendment Column for detailed explanation of the invention in the specification (1) Specification No. 4 “The inventors” in line 16 of the page is replaced with “
The inventor corrected this.

(2) In the same book, page 15, line 7, replace “tada” with “mata.”
I am corrected.

(3) In the second line of page 39 of the same book, "after dilution" is corrected to "diluent."

Claims (1)

[Claims] In a method of manufacturing a lithographic printing plate by imagewise exposing a photosensitive lithographic printing plate, treating it with an aqueous alkaline developer, and immediately treating it with a desensitizing agent without passing through a water washing step, the method comprises: A method for producing a lithographic printing plate, characterized in that the photosensitive composition forming the photosensitive layer contains 50% by weight or more of a polyurethane resin having a substituent having an acidic hydrogen atom.