JPS61172147A - Correcting agent for lithographic printing plate - Google Patents

Abstract

PURPOSE:To enable the quick erasure of an unnecessary image part in a correcting agent contg. a glycolic compd., acidic material and thickener by using the glycolic compd. having specific structure and using a fluorine-contg. acid for the above-mentioned acidic material. CONSTITUTION:The glycolic compd. has the structure expressed by formula in a correcting agent for a lithographic printing plate contg. the glycolic compd., acidic material and thickener. The embodiment of the compd. satisfying formula I is exemplified by, for example, ethylene glycol monophenyl (or tolyl) ether, propylene glycol monophenyl (or tolyl) ether diethylene glycol monophenyl (or tolyl) ether, etc. These compds. added with halogen atoms of fluorine, bromine, chlorine, iodine, etc. are also enumerated. the ethylene glycol monophenyl (or tolyl) ether and propylene glycol monophenyl (or tolyl) ether among the above-mentioned comps. have the high erasability of the image part and are therefore more preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a corrector for lithographic printing plates, and more specifically, for erasing unnecessary image areas (areas that receive printing ink) of lithographic printing plates. The present invention relates to a correction agent used for

(Prior Art) Lithographic printing plates For example, in lithographic printing plates such as those produced by photolithography, unnecessary images or image areas that need to be deleted or corrected may inevitably occur, making it necessary to correct them. Become. - For example, stains, scratches, cuts, etc. in the original film may cause over- or under-exposure of the printing plate surface, resulting in unwanted image areas that need to be corrected.

Correcting agents for removing unnecessary image areas from such lithographic printing plates have traditionally been concentrated strong alkaline solutions or acidic solutions containing hydrofluoric acid, which corrode the support and remove image areas. It was known. However, due to the danger to the human body, skin, etc., various improvements have been made. For example, a) Glycol, polyglycol, glycol ether or polyglycol ether described in Japanese Patent Publication No. 46-16047, b) 10% by weight of neutral organic solvents other than those listed in a), C ) 3-25% by weight of water, d
) compositions containing 0.5 to 15% by weight of acidic substances, e) 5 to 25% by weight of thickening agents; a) 50 to 90% by weight of organic solvents; ) Surfactant 3-5% by weight, C) Gum arabic 0.5-5% by weight
, d) compositions containing 0.5 to 15% by weight of phosphoric acid.

However, in recent years, there has been a trend toward higher printing durability (increased printing durability) of lithographic printing plates, and the strengthening of image areas has lowered the solubility in correction agents, making corrections increasingly difficult. To give a specific example, for example, even if it appears to have been erased using a conventional correction agent, it is not completely erased, and an image area remains, making it easy for printing ink to adhere to this area during printing. This can cause stains on printed matter. In addition, there was a strong desire to speed up the correction work, and the conventional performance was insufficient.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a lithographic printing plate corrector that can quickly erase unnecessary image areas.

Still another object of the present invention is to provide a correcting agent which is capable of completely erasing unnecessary image areas of a lithographic printing plate having a strong image area and having a high printing durability.

Structure of the Invention The present inventors have conducted intensive research to achieve the above object, and as a result, have arrived at the present invention. In the plate correction agent, the glycol compound has the structure of the following general formula [I], (I) R3: hydrogen or an alkyl group having 1 to 2 carbon atoms R2: an alkylene group having 2 to 4 carbon atoms or alkenylene group n: an integer of 1 to 3. The acidic substance is a fluorine-containing acid.

The modifier of the present invention, which contains a compound having the structure of general formula [I] above, a fluoric acid, and a thickener, has one of its components.
It has significantly higher erasability than those lacking one, and also has excellent performance that does not have any negative effect on adjacent lines (necessary lines close to the image area to be erased). It has been found.

In particular, using correction agents containing glycol compounds, acids, and thickeners, which were developed to avoid the use of fluorine compounds, what remains in the areas that appear to have been erased can be removed. It is specifically and completely removed only by the inventive modifier.

The present invention will be explained in detail below.

Specific examples of the compound satisfying the general formula [I] contained in the modifier of the present invention include ethylene glycol monophenyl (or tolyl) ether, globylene glycol monophenyl (or tolyl) ether, diethylene glycol monophenyl (or tolyl) ether, Phenyl (or tolyl) ether, diethylene glycol monophenyl (or tolyl) ether, triethylene glycol monophenyl (1?, t)
! Tolyl) ether, triflopylene gelylcol monophenyl (or tolyl) ether, trimethylene glycol monophenyl (t ta)! ) + full) ether, di-trimethylene glycol monophenyl (or tolyl) ether, tri(trimethylene glycol) 17 = r
-l) monophenyl (or tolyl) ether, and the like.

Also included are compounds obtained by adding halogen atoms such as fluorine, bromine, chlorine, and iodine to these compounds.

Among these, ethylene glycol monophenyl (or tolyl) ether and globylene glycol monophenyl (or tolyl) ether are preferred because they have high erasability in the image area.

The compound satisfying the above general formula [I] may be used alone or in combination.
It is preferable to contain 5 to 90% by weight, more preferably 10 to 85% by weight, most preferably 15 to 80% by weight based on the total weight of the corrector of the present invention. It can be contained within the range of .

Examples of the fluorine-containing acids include hydrofluoric acid, potassium hydrogen fluoride, sodium hydrogen fluoride, lithium hydrogen fluoride, borofluoric acid, hydrofluorosilicic acid, and zirconate fluoride. , no-funium hydrofluoric acid,
These include titanium heptatonic acid. Hydrofluoric acid, potassium hydrogen fluoride, sodium hydrogen fluoride,
Lithium hydrogen fluoride fluoride, borofluoric acid, hydrofluorosilicic acid, and fluorozirconic acid are preferable because they have better erasing performance. More preferably, hydrofluoric acid,
Hydrofluoroboric acid, hydrofluorosilicic acid, and most preferably hydrofluoric acid.

The above fluorine-containing acids can be used alone or in combination of two or more, and are
．． It is preferably contained in an amount of 1 to 10% by weight, preferably 0.3 to 5% by weight, particularly preferably 0.4 to 3% by weight.

Examples of thickeners include inorganic thickeners such as silicic acid fine powder, modified cellulose such as methylcellulose, hydroxypropyl methylcellulose, carboxymethylcellulose/Na salt, gum arabic, polyvinylpyrrolidone, polyvinyl methyl ether, polyethylene glycol, and polypropylene. /glycol, vinyl methyl ether-maleic anhydride copolymer, and vinyl acetate-maleic anhydride copolymer. Among them, modified cellulose, polyvinylpyrrolidone, and the above-mentioned two types of maleic anhydride copolymers are preferred, and modified cellulose such as hydroxypropyl methylcellulose and polyvinylpyrrolidone are most preferred. These thickeners can be used alone or in a mixture of two or more, and the amount added can be changed to achieve the desired viscosity, but preferably 0.5 to 25% by weight based on the modifier of the present invention. %, more preferably 1~
It is used in a range of 15% by weight.

The modifying agent of the present invention can further selectively contain organic solvents other than those represented by the general formula [I], acidic substances other than fluoric acid, water, surfactants, coloring pigments, etc. The agent performance can be further improved. These will be explained in detail below.

Examples of organic solvents other than those of the general formula [I] include ethers, ketones, lactones, alcohols, organic acids, and other hydrocarbon solvents. Typical ethers include glycol ethers, specifically ethylene glycol monoalkyl ethers and ethylene glycol dialkyl ethers of ethylene glycol with methyl, ethyl, impropyl, and butyl terna. , e.g. methyl of diethylene glycol
, diethylene glycol monoalkyl ethers such as ethyl, isopropyl, isobutyl ether, diethylene glycol dialkyl ethers, triethylene glycol monoalkyl ethers such as methyl, ethyl, butyl ether of triethylene glycol, triethylene glycol dialkyl ethers Examples include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monoalcohol ether acetate. Examples of ketones include methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl amyl ketone, methyl hexyl ketone, diethyl ketone, ethyl butyl ketone, butylone, valerone, mesityl oxide, acetylacetone, acetonylacetone, cyclohexanone, and ethyl acetoacetate. , methylcyclohexanone, acetophenone and the like. Examples of lactones include butyrolactone, valerolactone,
Examples include hexanolactone. Examples of alcohols include aromatic alcohols, alicyclic alcohols/L', aliphatic alcohols,
Examples include polyhydric alcohols and polyhydric alcohols. Aromatic alcohols include, for example, benzyl alcohol, α-phenylethyl alcohol, β-phenylethyl alcohol,
Those with saturated aromatic hydrocarbon side chains such as tolylcarbinol, 7-taryl alcohol, phenylpropyl alcohol, and vanillyl alcohol, and those with unsaturated aromatic hydrocarbon side chains such as cinnamyl alcohol. Some have bonds. Alicyclic alcohols include, for example, cyclohexanol, cyclopentanol, and the terpene alcohol sterine, such as hocalanoline. Aliphatic alcohols include, for example, methyl alcohol, ethyl alcohol, furopanol, phthanol, pentanol, hexanol, heptatool, octatool, nonanol, decanol, undecanol, dodecanol,
Saturated aliphatic-hydric alcohols such as tridecanol, tetradecanol, pentadecanol, hexadecanol, octadecanol, e.g. evalyl alcohol, oleyl alcohol, elaisyl alcohol, lylyl alcohol, lylyl alcohol, cheraniol, clopal There are unsaturated aliphatic-hydric alcohols such as gyl alcohol. Polyhydric alcohols include dihydric alcohols such as ethylene glycol and propanediol, and trihydric alcohols such as glycerin.

Examples of organic acids include saturated fatty acids such as formic acid, acetic acid, acetic anhydride, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecylic acid, and lauric acid; for example, acrylic acid; There are unsaturated fatty acids such as crotonic acid, randecylenoic acid, oleic acid, linoleic acid, ricinoleic acid, and rinnic acid.

Other hydrocarbon solvents include, for example, boiling point Kani 20
In addition to petroleum fractions around ~250℃, toluene, xylene, benzene, turpentine oil, kerosene, lactams such as N-methylpyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, dioxane, etc. It will be done.

Among these organic solvents, preferred organic solvents other than the above general formula CI are diethylene glycol monoalkyl ethers, ketones, raftones, alcohols, acetic acid, acetic anhydride, and other hydrocarbon solvents. . More preferably, ketones, aromatic alcohols,
Unsaturated aliphatic alcohols, polyhydric alcohols, acetic anhydride, most preferably cyclohexanone, ethyl acetoacetate, aromatic alcohols. The above-mentioned organic solvents can be used alone or in combination of two or more, and are 5 to 85% by weight, preferably 20 to 85% by weight, based on the modifier of the present invention.
It is contained in an amount of 80% by weight, most preferably in the range of 35-70% by weight.

Examples of acidic substances other than fluoric acid include hydrochloric acid, sulfuric acid,
Inorganic acids such as persulfuric acid, phosphoric acid, nitric acid, permanganic acid, citric acid, malic acid, formic acid, lactic acid, oxalic acid, trichloroacetic acid,
Examples include acidic acids such as tandinoic acid, phytic acid, and p-toluenesulfonic acid phospho/acids.

Examples of the phosphonic acid include 1-hydroxyethylidene-1,1-diphosphonic acid, 1,2-diphosphonic-1,2
-dicarboxyetatu, 1.2.2.3-tetraphosphonopropane, 2(2'-phosphonoethyl)pyridine, aminotri(methylenephosphonic acid), vinylphosphonic acid,
Examples include polyvinylphosphonic acid, 2-phosphonoethane-1-sulfonic acid, and water-soluble copolymers of vinylphosphonic acid and acrylic acid and/or vinyl acetate. Among these acidic substances, phosphoric acid and phosphonic acid are preferable because they improve the correction effect, and phosphonic acid is more preferable because it reduces corrosion of non-image areas after correction. These acidic substances can be used alone or in combination of two or more, and are 0.1 to 10% of the total weight of the correction agent.
The content is preferably in the range of 0.3 to 5.0 weight %, particularly preferably 0.5 to 3.0 weight %.

Water is contained in various components such as acids and is necessarily added, but it can also be added selectively.
The modifier of the present invention has a subtle effect on its performance.

For this reason, the preferable amount to be added is 1 to 1 to
It is 30% by weight, more preferably 3 to □□□%.

The modifier of the present invention may contain a surfactant, such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyrylphenyl ether, polyoxyethylene polyoxypropylene alkyl ether, etc. , glycerin fatty acid partial esters, sorbitan fatty acid partial esters,
Pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid esters, oxyethylene oxypropylene block copolymers, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, Polyglycerin fatty acid partial esters, polyoxyethylenized castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid jetanolamides, N, N-
Nonionic surfactants such as bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, trialkylamine oxides, fatty acid salts, avicenoates, hydroxyalkanesulfonates, alkanesulfonate/ acid salts,
Dialkylsulfosuccinate ester salts, linear alkylbenzenesulfonates, branched alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethyleneprobyl sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N - Methyl-N-oleyl taurine sodium salts, N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfo/acid salts, sulfated castor oil, sulfated beef leg oil, sulfate ester salts of fatty acid alkyl esters, alkyl sulfate ester salts, Polyoxyethylene alkyl ether sulfate ester salts, fatty acid monoglyceride sulfate ester salts, polyoxyethylene alkyl phenyl ether sulfate ester [lj[, yN lyoxyethylene styrylphenyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphorus] Salts for acid esthetics, yt'! Lioxyethylene alkyl phenyl ether phosphate ester salts, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin/maleic anhydride copolymer, naphthalene sulfonate formalin condensates Anionic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, cationic surfactants such as polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, aξ ) Examples include amphoteric surfactants such as sulfuric esters and imidacillins. Among the surfactants listed above, polyoxyethylene can also be read as polyoxyalkylene such as polyoxymethylene, polyoxypropylene, and polyoxybutylene.

Among these, nonionic surfactants and anionic surfactants are preferred, and surfactants with an HLB of 9 or more are more preferred since the gold component contained in the modifier can be mixed well with the surfactants. Furthermore, polyoxyethylene alkyl phenyl ethers, oxyethylene oxypropylene block copolymers, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, and polyglycerin fatty acid partial esters are modifiers. This is preferable in order to improve the image area erasing effect. Most preferred is oxyethylene oxypropylene block copolymer. Two or more of these surfactants may be used in combination, and the amount of these surfactants may be 1 to 4 in total based on the total weight of the correction agent of the present invention.
The content is 0% by weight, preferably 3 to 25% by weight.

Coloring pigments can be included when visual contrast is desired, and specific examples include dyes such as crystal violet, safranin, brilliant blue, malachite green, and acidrhodamine B, as well as inorganic pigments and organic pigments. . These colorants are present in an amount of 0.0001 to 0.05% by weight based on the total weight of the correction agent according to the present invention.
, preferably in a range of 0.001 to 0.01% by weight.

The correcting agent of the present invention can be applied to positive-working and negative-working photosensitive planographic printing plates (hereinafter referred to as PS plates), and in particular, planographic printing plates obtained by plate-making from PS plates provided with a negative-working photosensitive layer on a support. It is advantageously used when correcting and erasing the image portion of the image.

These PS versions will be explained in detail below.

The PS plate support used in the present invention is a dimensionally stable plate-like material, and includes those conventionally used as printing plate supports. Examples of such supports include paper, paper laminated with plastics (e.g. polyethylene, polypropylene, polystyrene, etc.), aluminum plates (including aluminum alloys), zinc plates, steel plates, iron plates,
Metal plates such as composite metal plates (for example, iron plates coated with chromium), such as cellulose diacetate, cellulose triacetate,
Plastic films such as cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., paper or plastic film laminated or vapor-deposited with the above metals. , a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327.

The PS plate support used in the present invention is hydrophilic and has a columnar surface. Here, the term "hydrophilic surface" refers to a surface that becomes wet with dampening water and repels printing ink when the lithographic printing plate is mounted on a printing machine and printed under standard conditions. The surface of the support is preferably subjected to hydrophilic treatment. There are various methods for hydrophilic treatment. For example, in the case of a support with a plastic surface, methods such as chemical treatment, electric discharge treatment, flame treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, activated plasma treatment, laser treatment, etc. and undercoating after these treatments are used. There is a method of applying layers. In addition, in the case of a support having a metal surface such as aluminum, graining treatment such as brush polishing and electrolytic polishing, immersion treatment in an aqueous solution of sodium silicate, fluoridated zirconate, phosphate, etc. There are plating, coating, anodizing treatments, etc.

Among the above-mentioned supports, a plate having a grained or anodized aluminum surface, or a chromium-coated iron plate is preferable because it improves the adhesion of the photosensitive layer.

Anodizing baths include hydrochloric acid, nitric acid, chromic acid, boric acid,
Examples include aqueous solutions of various acids such as sulfuric acid, persulfuric acid, phosphoric acid, sul-7 amino acids, oxalic acid, and the like. An aluminum plate that has been grained and further anodized is more preferred. An aluminum plate that has been brush-polished and further anodized, or an aluminum plate that has been brush-polished and electrolytically polished and further anodized has particularly favorable adhesion with the photosensitive layer, so the resulting PS plate has a long printing life. The modifier of the present invention is particularly advantageous because of its high strength. Furthermore, surface roughness is known as one method of expressing the hydrophilicity of a support, and it has been found that this surface roughness also serves as a measure of the adhesiveness of the photosensitive layer. Therefore, the center line average roughness Ra
[gn:l is preferably 0.40 or more, more preferably 0.50 or more and O, SO or less. It shows the most preferable adhesiveness, and the preferable range is 0.60 or more and 0.80 or less.

(Measuring instrument manufactured by Perdef AG, West Germany. Beltmeter, photosensitive composition of the photosensitive layer provided on the hydrophilic surface of the tracer support contains a diazo compound, British Patent No. 1,235.281 and photosensitive compositions containing azide compounds as described in U.S. Pat. Photosensitive compositions comprising U.S. Pat. No. 4.072.528 and U.S. Pat.
, No. 072,527, a photosensitive composition containing a photopolymerizable photopolymer as described in each specification, JP-A-56
-19063 and 56-29250, JP-A-52-6250
Examples include silver 10-genide emulsion compositions as described in No. 1 and No. 56-111 M-52. Among these photosensitive compositions, photosensitive compositions containing diazo compounds have excellent properties such as storage stability of the photosensitive layer, development performance such as development latitude, image performance such as image quality, ink receptivity, oil sensitivity, abrasion resistance, etc. It is preferred because of its overall excellent printing performance and low pollution properties of the developer used.

Photosensitive compositions containing diazo compounds can be divided into negative type and positive type.

The negative photosensitive composition containing a diazo compound contains a photosensitive diazo compound and preferably a polymer compound. Conventionally known photosensitive diazo compounds can be used, but organic compounds are preferably used. Examples include salts of solvent-soluble diazo resins, such as salts of p-diazodiphenylamine, formaldehyde or acetaldehyde condensates, and hexafluorophosphate, and m of 2-hydroxy-4-methoxybenzophenone-5-sulfonate. It will be done.

As a particularly preferable example, the following general formula (1): (wherein R,
, R4 and R represent a hydrogen atom, an alkyl group or an alkoxy group, R represents a hydrogen atom, an alkyl group or a phenyl group, X represents PF or BF4, m is 1 to 200
% or more, preferably 20 to 60 mol%.
Examples include those containing.

The content of diazo resin in the photosensitive composition according to the present invention is
1~70ii! li%, preferably 3 to 60% by weight.

Examples of polymer compounds include acrylic acid or methacrylic acid copolymers, crotonic acid copolymers, itaconic acid copolymers, maleic acid copolymers, cellulose derivatives having carboxyl groups in their side chains, and cellulose derivatives having carboxyl groups in their side chains. Polyvinyl alcohol derivatives having carboxyl groups, hydroxyalkyl acrylate or methacrylate copolymers having carboxyl groups in side chains, unsaturated polyester resins having carboxyl groups, etc. are preferably used. More preferably the acid value is 1
It is a high molecular compound with a molecular weight of 0 to 300. More preferably, a polymer containing a structural unit represented by the following general formula (III) and a structural unit represented by the following general formula (rV) described in JP-A-50-118802, JP-A-50-118802,
7-192951, and a monomer unit having an aromatic hydroxyl group and the general formula (IV)
A polymer containing the structural unit shown in has been used.

Rγ (In) (IV) (in the general formula, R
6 represents a hydrogen atom or a methyl group, R? (represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, R3 represents a hydrogen atom or a methyl group, and g represents an integer of 1 to 10) Conventionally known diazo compounds used in positive photosensitive compositions Typical examples include 0-quinonediazides, preferably 0-quinonediazides.
Examples include naphthoquinone diazide compounds. Among the 0-naphthoquinonediazide compounds, in particular, 0-naphthoquinonediazide sulfonic acid ester or 0-naphthoquinonediazidecarboxylic acid ester of various hydroxy compounds, and O-naphthoquinonediazide sulfonic acid amide or 0-naphthoquinonediazide of aromatic amino compounds. Carboxylic acid amides are preferred. Preferred hydroxy compounds include subdivision resins of phenols and carbonyl group-containing compounds. These phenols include phenol,
Cresol, resorcinol, pyrogallol, etc. may be mentioned, and examples of the above-mentioned compounds containing a group include formaldehyde, benzaldehyde, and acetone.

Preferred hydroxyl compounds include phenol-formaldehyde It 2 resin, cresol-formaldehyde resin, pyrogallol-acetone resin, and resorcinol-benzaldehyde resin.

Typical specific examples of 0-quinonediazide compounds include:
Synthesis of benzoquinone-(1,2)-diazide sulfonic acid or naphthoquinone-(1,2)-diazide sulfonic acid with phenol-formaldehyde resin or cresol-formaldehyde resin, described in JP-A-56-1044 Naphthoquinone-(1,2)-diazide-(2)-5-sulfonic acid ester with tresilcin-benzaldehyde resin, U.S. Pat. No. 3,635,70
Naphthoquinone (1°2) described in Specification No. 9
-Ester of diazide sulfonic acid and pyrogallol acetone resin, naphthoquinone-(1,2)-diazide-(2)- described in JP-A-55-76346
Examples include esters of 5-sulfonic acid and resorcinol-pyrogallol-acetone copolycondensate. Other useful 0
- As a quinonediazide compound, JP-A-50-117
503, a polyester having a hydroxyl group at the end is subjected to an esterification reaction with 0-naphthoquinonediazide sulfonyl chloride, JP-A No. 503
A homopolymer of p-hydroxystyrene or a copolymer with other copolymerizable heptamers as described in Japanese Patent No. 0-113305 is esterified with 0-naphthoquinonediazide sulfonyl chloride, especially Ester of bisphenol formaldehyde resin and 0-quinonediazide sulfonic acid described in Publication No. 54-29922, US patent! A condensate of a copolymer of alkyl acrylate, acroyloxyalkyl carbonate, and hydroxyalkyl acrylate and 0-quinonediazide sulfonyl chloride described in Japanese Patent Publication No. 17481/1989, as described in Japanese Patent Publication No. 17481/1983. The reaction product of a copolymerization product of styrene and phenol US with o-quinonediazide sulfonic acid, p-aminostyrene as described in U.S. Pat. No. 3,759,711; Amides of copolymers with other copolymerizable heptamers and 0-naphthoquinonediazide sulfone 1k or 0-naphthoquinonediazidecarboxylic acid, and esters of polyhydroxybenzophenone and 0-naphthoquinonediazide sulfonyl chloride, etc. can be mentioned.

Although these 0-naphthoquinone diazide compounds can be used alone, it is preferable to mix them with an alkali-soluble resin and provide this mixture as a photosensitive layer. Suitable alkali-soluble resins include novolak-type phenolic resins, specifically phenol formaldehyde resins,
Cresol formaldehyde resin, JP-A-55-578
Phenol/cresol formaldehyde copolycondensate resins such as those described in Japanese Patent No. 41 are included.

Furthermore, as described in JP-A-50-125806, in addition to the above-mentioned phenol resin, phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms such as t-butylphenol formaldehyde resin and formaldehyde are used. When used in combination with a condensate of
Even more preferred.

The content of the 0-quinonediazide compound is preferably 5 to 80% by weight, particularly preferably 10 to 50tt%, based on the total solid content of the photosensitive composition. The content of the alkali-soluble resin is 30 to 90% by weight based on the total solid content of the photosensitive composition.
is preferred, and particularly preferably t% by weight.

The photosensitive composition can be provided in multiple layers, and additives such as dyes, plasticizers, and components imparting printout performance can be added as necessary.

The coating thickness of the photosensitive composition provided on the support is 0.
1-79/lrl is preferred, more preferably 0.5-79/lrl
49/Go. The corrective agent of the present invention becomes more effective at 1.5 g to 497 m, and is most effective at 2.5 g to 497 m.
0-3. It is ogim.

The 28 plate thus obtained is exposed through a transparent original to an actinic light rich source such as a carbon arc lamp, mercury lamp, metal noride lamp, tungsten lamp, xenon lamp, etc., and then developed.

The developer used in the present invention may vary depending on the type of photosensitive composition used in the 28th plate, but preferably contains at least one of an alkaline agent and an organic bath agent, Various selections are made depending on the type.

Is this 4? It is described in detail in Japanese Patent Publication No. 59-58431.

The developing solution used for the 28th plate with a negative diazo photosensitive layer generally contains ethylene glycol monophenyl ether and benzyl alcohol, and the developing solution for the positive 28th plate is C5 in molar ratio
ift')/CM] = 0.5~1.5 (
(5tyx) and [M] are respectively S10. and the molar concentration of total alkali metals such as K, Na, Li, etc., and 810. 0.8 to 8.
! Those containing f% are common.

Methods for developing the 28th plate that has been imagewise exposed with the above developer include a method of jetting the developer from multiple nozzles, a method of immersing it in the developer, and a method of wiping with a sponge moistened with the developer. , various conventionally known methods are possible.

As mentioned above, if there is an unnecessary image area on the lithographic printing plate obtained by subjecting the PS plate to image exposure and development, the image area can be erased by applying the correction agent of the present invention on the image area. be done.

When the correcting agent of the present invention is applied to the lilljgR portion of a lithographic printing plate, it is preferable to wash it with water after visualizing it, and to swipe the washing water through Φ- before erasing. A specific method for erasing is to soak a brush in a correction agent, apply it to the image area, and apply it to the image area for about 10 minutes.
A common method is to leave the correction agent for a few seconds or several minutes, or to rub it lightly with a brush after applying it, and then wash it off with water.

The lithographic printing plate from which the unnecessary portions of the artist have been erased in this manner is subjected to the usual processing steps such as inking or gumming, and is then subjected to printing.

The correction agent of the present invention can completely erase unnecessary image areas and eliminate troubles during printing due to incomplete erasure, thereby improving printing efficiency. Further, since the correcting agent of the present invention can easily and quickly erase unnecessary image areas, the efficiency of plate-making work is improved. Further, the correcting agent of the present invention has a high adhesive strength between the support and the photosensitive layer, and also has extremely high erasability of a flat PS plate with printing durability.The present invention will be specifically described below with reference to Examples.

In the following examples, "parts" represent parts by weight, and "parts" represent parts by weight.
%” means overlapping %.

Example 1 An aluminum plate having a thickness of 0.30 m was polished with a nylon brush and anodized in a phosphoric acid bath. At this time, the oxide film on the aluminum plate was 11■/dn? Met.

Further, the pores were sealed with an aqueous sodium metasilicate solution to obtain a support for a lithographic printing plate. Center roughness Ra of this material
was 0.62-67. A photosensitive liquid having the following composition was coated on this support, and then dried for 2 minutes at a temperature of 10°C to give a photosensitive layer thickness of 231 m9/d. A negative PS version was obtained.

(Photosensitive liquid) Copolymer 320 parts Diazo resin 26 parts Victoria Pure Blue OH 6 parts (manufactured by Hodokugaya Chemical Co., Ltd.) Methylseronlupe 3000 parts However, the above copolymer resin contains p-hydroxyphenyl methacrylic in weight ratio. It has a composition (molar ratio) of amide/acrylonitrile/ethyl acrylate/methacrylic acid = 8/24/59.5/8.5, and average molecular weight (MW) = 5.8X
10, and the diazo resin is a hexafluorophosphate of a condensate of p-diazodiphenylamine and paraformaldehyde (My = 2.80 be.

A halftone photographic transparent positive was placed on top of this, and the length was 0.8 m using the metal halide lamp and Idol Fin 2000.
Second exposure was carried out from a distance of , and development was performed with the following developer to obtain a printing plate.

(Developer) Benzyl alcohol 5.0 parts Sodium carbonate 0.5 parts Sodium sulfite 0.5 parts 3-Methyl-
3-methoxybutanol 26.5 parts water
After 100 copies, unnecessary image areas were erased using the following correction agent of the present invention, and it was possible to erase them in 9 seconds.

(Modifier of the present invention) Ethylene glycol monophenyl ether 18 parts Cyclohexanone 53 parts Hydroxypropylene methyl cellulose 8.5 g 55% Hydrofluoric acid 1.8 parts Oxyethylene oxypropylene block cobolimer - 8 parts Water
Part 11 Example 2 An aluminum plate with a thickness of 0.24 mm was degreased by immersing it in a 20% sodium phosphate water bath, and then electrolytically polished in a 0.2 N hydrochloric acid bath at a current density of 3 A/Z. Anodized in a sulfuric acid bath. At this time, the amount of anodic oxidation was 3.09/rrt. Further, the pores were sealed with an aqueous sodium metasilicate solution to obtain a support for a lithographic printing plate. A photosensitive solution having the following composition was applied to this aluminum 9 film. The plate was then dried at a temperature of 90° C. for 2 minutes to obtain a film thickness of 18 m9/dm'' to obtain a negative WPS plate that can be easily erased.

(Photosensitive G) Copolymer 5.0 parts Diazo resin 0.5 parts Methyl cellosolve 100 parts However, the same copolymer resin and diazo resin as in Example 1 were used.

A halftone photographic transparence image was brought into close contact thereon, and exposure was carried out in the same manner as in Example 1, and development was carried out in the same manner.

The unnecessary image area of the obtained printing plate was shown in Example 1. When I erased it with a correction agent, it was erased within 5 seconds.

Also, Example 1. When I tried erasing by replacing ethylene glycol monophenyl ether with cyclohexanone in the components of the correction agent used in , I was able to erase it in about (to) seconds. However, when this correction agent was used to erase the image area of the printing plate with high printing durability used in Example 16, it could not be completely erased even after 5 minutes.

Example 3゜thickness 0.30. An aluminum plate was polished with a nylon brush and then anodized in a phosphoric acid bath. At this time, the oxide film thickness on the board was 131n9/dlrX, and the center line average roughness Ra was 0.49 to 0.60. A photosensitive liquid having the following composition was applied to this support and dried in the same manner as in Example 1 to give a photosensitive layer thickness of 15119/di'.
A negative type 28 plate with high adhesiveness between the photosensitive layer and the support was obtained.

(Photosensitive liquid) Co-1i aggregate 32° part Diazo resin 26 parts Victoria Pure Blue BOHS part Jurimer AC-IQL (manufactured by Nippon Tsumugi Pharmaceutical ■)
6 parts Methyl cellosolve 3000 parts The above copolymer and diazo resin were as described in Example 1. It is similar to Example 1. It was exposed in the same manner as above and developed with the following developer to obtain a printing plate.

(Developer) Jetanolamine 25.0 parts Sodium sulfite 10.0 parts Benzyl alcohol 2.0 parts Water
152
When unnecessary image areas were erased using the following correction agent of the present invention, it was possible to erase them in a leap second.

(Modifier of the present invention) Propylene glycol monophenyl ether 20 parts Cyclohexanone 50 parts Hydroxypropyl methyl cellulose 7 parts 55% Hydrofluoric acid 1.8 parts Water
11 parts Pigment (edible f 101 J O, 002 parts Example 4) Propylene glycol monophenyl ether, a component of the corrector used in Example 3., was replaced with the same amount of methylcarpitol to obtain the same amount as in Example 3. When the image area of the printed printing plate was erased, it could not be erased even after 3 minutes.

Example 5゜Example 1. The unnecessary image part of the printing plate obtained in the same way as
When erased using the following correction agent of the present invention, it was possible to erase it in 3 minutes.

(Correcting agent of the present invention) Ethylene glycol monophenyl ether 66 parts β
-Phenylethyl alcohol 8 parts Hydroxypropyl methylcellulose 4 parts 55% hydrofluoric acid 1.8 parts 1-hydroxyethylidene-1,1-diphosphonic acid 2.5 parts
oxyethylene oxypropylene block copolymer
8 parts water
11 part pigment (edible f101)
0.002 parts Example 6゜Example 1. The unnecessary image part of the printing plate obtained in the same way as
Example 5. Ethylene glycol monophenyl ether was a component of the correcting agent, but when it was erased using the same modifier instead of diethylene glycol diethyl ether, it could not be completely erased even after 10 minutes. Similarly, Example 5
．． Even when erasing was carried out using a corrector containing only hydrofluoric acid, the erasure was not possible even after 10 minutes.

Example 7 An aluminum plate with a storage depth of 0.3 m was electrochemically roughened in a nitric acid solution, thoroughly washed, and then anodized in a sulfuric acid solution to form an oxide film of 2.51/lri on the aluminum plate. formed on the surface.

After washing with water and drying, 3 parts of the esterified product of resorcin benzaldehyde resin tonaphthoquinone 1,2-diazide-5-sulfonyl chloride synthesized according to the example of JP-A No. 56-1044, 9 parts of talesol formalin novolac resin and Victoria・Viea Blue BOH
(Hodogaya Chemical Industry Co., Ltd.) A photosensitive solution prepared by dissolving 0.12 parts of 2-methoxyethanol in 100 parts of 2-methoxyethanol was applied onto the above support using a rotary coater and dried, resulting in a photosensitivity of 2.8 fi/lt? A positive type 28 plate with layers was obtained.

A halftone photographic transparent positive was placed on top of this and Example 1 was applied from a distance of 0.8 m. Exposure for 60 seconds with the Metal/S Ride lamp used in , and the next current 1#! The solution was developed to obtain a printing plate.

(Dust image liquid) Potassium silicate A (SiO126%-&013.5%) 12
0 Mh86% potassium hydroxide 15
．． 5 parts water
After 500 copies, unnecessary image areas were erased using the following correcting agent of the present invention, and the images were completely erased in 15 seconds.

(Correcting agent of the present invention) Ethylene glycol monophenyl ether 10 [-diethylene glycol monotrile ether 10 parts xylene 6 parts dioxane 5 parts ethyl acetoacetate 10 parts dimethylformamide 10 parts cyclohexanone
20 parts hydroxypropyl methylcellulose 12 parts silicon dioxide
6.5 parts 42% borofluoric acid
1.2 parts 85% phosphoric acid
2.1 part 12 parts water
1o Part Example 8゜Example 7. The correcting agent used in Example 7 was prepared by excluding borofluoric acid. When I erased the image part of the print obtained in the same way, it took until it was completely erased (
9) It took more than a second.

From the above, it can be seen that the correcting agent of the present invention can quickly and completely erase unnecessary image areas of 1,000-print printing plates.

Claims (1)

[Claims] In a lithographic printing plate corrector containing a glycol compound, an acidic substance, and a thickener, the glycol compound has the structure of the following general formula [I], and the acidic substance contains a fluorine-containing substance. A lithographic printing plate corrector characterized by being an acid. [I] ▲Mathematical formulas, chemical formulas, tables, etc. are available▼ R_1: Hydrogen or an alkyl group with 1 to 2 carbon atoms. R_2: Alkylene group or alkenylene group having 2 to 4 carbon atoms. n: An integer of 1 to 3.