JPS6235363A - Method for processing photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To mixedly process negative type PS plates and positive type PS plates with the same automatic developing machine and to extremely minimize the generation of waste water by developing photosensitive lithographic printing plates by respective developing solns. to be exclusively used then subjecting the plates to a washing process by the same washing water to be cyclically used. CONSTITUTION:The selection of the developing soln. for negative or positive is executed by a control device 18 in accordance with the type information obtd. from an optical reflection sensor 17. The operations of developing soln. feed pumps 8, 11, a desensitizing soln. feed pump 4 and a developing replenisher pump 8' as well as the change over to a selector valve 12 are controlled by a control device 18. The exposed negative type PS plates and positive type PS plates are alternately processed in the above-mentioned manner. The plates are subjected to the washing process by the same washing water to be cyclically used.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for processing photosensitive lithographic printing plates, and more particularly to an improved processing method for processing negative-working and/or positive-working photosensitive lithographic printing plates using the same automatic processor. It is something to do.

[Background of the invention]

Exposed photosensitive lithographic printing plate (hereinafter simply referred to as 28th plate)
When processing a large number of sheets, it is common to use an automatic developing machine, but when processing negative 98 plates and positive 28 plates in common with one automatic developing machine, JP-A-58-
No. 223150 and No. 59-91446 disclose a method of processing using a two-story automatic developing machine having two developer tanks, but the drawback is that the automatic developing machine is large and complicated, making it impractical. there were. Japanese Utility Model Publication No. 54-151401 describes a method of processing 28 negative-type and 28-type plates using special developing solutions stored in separate storage tanks, but a large amount of water is consumed for washing. There was a problem. Also, JP-A-57-1929
Publication No. 52 discloses a method of processing negative and positive 28 plates with the same developer, but here too, washing with running water is performed using a large amount of washing water after development. In this case, there are disadvantages such as increased costs due to the use of a large amount of water and environmental pollution caused by washing wastewater. Furthermore, JP-A-57-158643, JP-A No. 59-5843
No. 1 and No. 59-57242, etc., describe a method of repeatedly using washing water, but there is still no satisfactory method. No method has been developed that can commonly process the 28th edition. The object of the present invention is to improve the above-mentioned drawbacks of the prior art and to provide a method for processing 28 plates which can process a double-sided PS plate with the same automatic development cost while minimizing the generation of waste water. Still another object of the present invention is to provide a method for processing 28 plates at low processing cost, which allows mixed processing of negative-type and positive-type PS plates.

[Means to solve problem α]

As a result of intensive research, the present inventors have found that the above purpose is to automatically transport a negative-type photosensitive lithographic printing plate and/or a positive-type photosensitive lithographic printing plate using an automatic developing device, and to In the same development tank, the negative-type and/or positive-type photosensitive plain printing plates are developed with respective dedicated developers that are stored in separate developer storage tanks and used in circulation, and then By using the same flush water that is recycled,
It has been found that the present invention can be achieved by a method for processing a photosensitive lithographic printing plate, which is characterized by washing with water. The present invention will be explained in detail below. The 28th plate targeted by the present invention can be developed with a developer containing water as a main component and an alkaline agent, and has a photosensitive layer coated on a support whose solubility changes with light irradiation. Alternatively, a soluble layer for forming an imager Lennost layer is provided on a support by an electrophotographic method or the like. Supports used for the 28th edition include paper, plastics (such as polyethylene, polypropylene, polystyrene, etc.), laminated paper, aluminum (including aluminum alloys), metal plates such as zinc, copper, etc. Films of plastics such as cellulose acetate, cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene polypropylene, polycarbonate, poly and nyl acetal, etc., paper or plastic films laminated or vapor-deposited with metals such as those mentioned above, aluminum or chrome. Examples include plated copper plates, among which, in particular,
Aluminum and aluminum-coated composite supports are preferred. Further, the surface of the aluminum material is preferably roughened for the purpose of increasing water retention and improving adhesion with the photosensitive layer. Examples of surface roughening methods include generally known methods such as brush polishing, ball polishing, electrolytic etching, chemical etching, liquid honing, sandblasting, etc., and combinations thereof, preferably brush polishing, electrolytic etching, and chemical etching. These include target etching and liquid honing.
Among these, surface roughening methods involving the use of electrolytic etching are particularly preferred. The electrolytic bath used in electrolytic etching is an aqueous solution containing an acid, an alkali, or a salt thereof, or an aqueous solution containing an organic solvent. Electrolytes are preferred. Further, the roughened aluminum plate is desmutted with an acid or alkali aqueous solution, if necessary. It is desirable that the aluminum plate thus obtained be anodized, particularly preferably treated with a solution containing sulfuric acid or phosphoric acid. Furthermore, if necessary, surface treatment such as pore sealing treatment and immersion in an aqueous solution of potassium zirconate can be performed. The photosensitive composition used in the present invention contains a photosensitive substance as an essential component, and the physical and chemical properties of the photosensitive substance do not change upon exposure or subsequent development. For example, there is a difference in solubility in a developing solution due to exposure, a difference in intermolecular adhesive strength before and after exposure, and a difference in affinity for water and oil due to exposure or subsequent development processing. Furthermore, a material capable of forming an image portion by an electrophotographic method can be used. Typical photosensitive substances include, for example, photosensitive diazo compounds, photosensitive azide compounds, compounds with ethylenically unsaturated double bonds, epoxy compounds that polymerize with acid catalysts, and C-0- that decomposes with acids. Examples include compounds having a C-group. Examples of photosensitive diazo compounds include O-quinonediazide compounds, which are positive types that change to alkali solubility when exposed to light, and aromatic noazonium salts, which are negative types whose solubility decreases when exposed to light. Specific examples of 0-quinonediazide compounds include, for example, JP-A-47-5303, JP-A-48-63802, and JP-A-48.
-63803, 49-38701, 56-10
No. 44, No. 56-1045. Special Publication No. 41-11222, No. 43-28403, No. 45-9610. Publications No. 49-17481, U.S. Patent No. 2,797
, 213 No. 3,046,120Ji! f, 3.1
No. 8111,210, No. 3,454,400. No. 3,544,323, No. 3,573,917, No. 3,674,495. No. 3,785,825, British Patent No. 1,277.1
No. 302, No. 1゜251.345, No. 1,267
．． No. 005, $1,329,888. No. 1,330,932, German patent $854,89
No. 0, etc., and the present invention can be preferably applied to the 25th edition in which these compounds are used alone or in combination as photosensitive components. These photosensitive components include aromatic hydroxy compounds. -quinone diazide sulfonic acid ester or 0-quinone diazide carboxylic acid ester, and 0-quinone diazide sulfonic acid or 0-quinone diazide carboxylic acid amide of an aromatic amino compound. - Those in which the quinonediat compound is used alone, and those in which it is mixed with an alkali-soluble resin and this mixture is provided as a photosensitive layer are included. The alkali-soluble resin includes novolac type phenolic resin, and specifically includes phenol formaldehyde resin, cresol formaldehyde uUa7 e/-lucresol mixed formaldehyde resin, cresol xylenol mixed formaldehyde Of resin, and the like. Furthermore, as described in VF Publication No. 50-125806, in addition to the above-mentioned phenolic resins, phenol resins having 3 to 3 carbon atoms such as Heap-Tyl 7-el formaldehyde resin
A combination of a phenol substituted with an alkyl group in No. 8 or a condensate of cresol and formaldehyde can also be used. If necessary, additives such as dyes, plasticizers, and components imparting printout performance can be added to the photosensitive layer containing an 0-quinonediazide compound as a photosensitive component. The amount per unit area of the photosensitive layer containing the 0-quinonediazide compound as a photosensitive component is at least about 0.5 to 78/l11
The present invention can be applied to the following ranges. There is no particular need to change the image exposure of the positive type 28 plate to which the method of the present invention is applied, and a conventional method may be used. Typical photosensitive components of the negative photosensitive layer are diazo compounds, such as diazo resins which are condensates of diazonium salts and/or p-diazophenylamine and formaldehyde, as described in Japanese Patent Publication No. 52-7364. 7-enol salt or fluorocaprate of p-diazodiphenylamine, 3-medoxynophenylamine-4 described in Japanese Patent Publication No. 49-48001
- Diazo resin consisting of an organic solvent soluble salt of a copolycondensate of noazonium chloride, 4-nitronophenylamine and formaldehyde, 2-methoxy-4-hydroxy of a condensate of p-diazodiphenylamine and formaldehyde Examples include -5 benzoylbenzenesulfonate, tetrafluoroborate, a condensate of p-diazodiphenylamine and formaldehyde, and hexafluorophosphate. The present invention can also be preferably applied to negative PS plates containing these as photosensitive components. In addition to those using these diazo compounds alone, the present invention can also be applied to those used in combination with various resins in order to improve the physical properties of the photosensitive layer. Examples of the darkening resin include copolymers having an alcoholic hydroxyl group in the side chain described in Baka JP-A No. 50-118802, such as shera ivy, derivatives of polyvinyl alcohol, and JP-A No. 55-155355. Examples include copolymers having phenolic hydroxyl groups in side chains as described in . These resins include copolymers containing at least 50% by weight of structural units represented by the following general formula;
R1 -(CH2-C) -COO-(CH2CHO)-nH (In the formula, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n is 1 to ) and 1 to 80 mol% of monomer units having an aromatic hydroxyl group, and 5 to 90 mol% of acrylic ester and/or methacrylic ester monomer units, and 10 to 200 mol% Includes polymer compounds with an acid value of The photosensitive layer of the negative PS plate to which the processing method of the present invention is applied may further contain additives such as dyes, plasticizers, and components imparting printout performance. The amount per unit area of the photosensitive layer is at least 0.1 to
The present invention can be applied to a range of 7 g/m2. There is no particular need to change the image exposure of the negative PS plate processed by the processing method of the present invention, and a conventional method may be used. Among the aqueous alkaline developers used in the present invention, for negative PS plates that use diazo compounds as photosensitive substances, water is used as a solvent with alkaline agents, organic solvents, anionic surfactants, sulfites, etc. The one that has been dried is used. Examples of alkaline agents include sodium silicate, potassium silicate, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate, dibasic potassium phosphate, tribasic ammonium phosphate, and dibasic sodium phosphate. Inorganic alkaline agents such as ammonium diphosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc., organic alkaline agents such as mono-, di-, or triethanolamine and tetraalkylammonium hydroxide; Ammonium silicate and the like are useful. The content of alkaline agent in the developer composition is 0.05
It is suitable to use in the range of ~20% by weight,
More preferably, it is 0.1 to 10 weight percent. Useful organic solvents include ethylene glycol monophenyl ether, pencil alcohol, and low propyl alcohol. The content of the organic solvent in the developer composition is 0.
A range of 5 to 15 weight percent is preferred, with a more preferred range of 1 to 5 weight percent. As anionic surfactants, higher alcohols (cm
~C2□) Sulfuric ester salts [e.g., sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, rTeepol B-8
1J (trade name - Shell Chemical Co., Ltd.), sodium chloride alkyl sulfate, etc.]'S aliphatic alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate ester, etc.), alkylaryl sulfonates (e.g., V-decyl sodium salt of benzenesulfonic acid, sodium salt of isopropylnaphthalenesulfonic acid, sodium salt of nona7talinnosulfonic acid, sodium salt of metanitrobenzenesulfonic acid, etc.), sulfonic acid salts of alkylamides (e.g., C,, H, C0NCH2Cl12SO3Ha
etc.) Dibasic CH. There are sulfones and acid salts of fatty acid esters (for example, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.). Among these, sulfonate salts are particularly preferably used. As a sulfite, it has the function of dissolving water-insoluble noazo υj in an aqueous solution, and in particular, in the development of PS plates consisting of a photosensitive layer in combination with a hydrophobic tree, it is possible to prevent stains even after a long period of time has passed since the plate was manufactured. You can make a print version. Useful sulfites include alkali metal salts such as sodium, potassium, and lithium, and alkaline earth metal salts such as magnesium. On the other hand, for a positive PS plate having a photosensitive layer containing an 0-quinonediazide compound, the alkali agent is added at a concentration of 0.1 to 30%.
．． An aqueous solution containing 1% by weight, preferably 0.5 to 20% by weight, is used, and is usually used at a pH in the range of 9 to 13. The following additives can be added to such a developer in order to further improve the developing performance. For example, JP-A-5
Neutral salts such as NaCl and KCIKBr described in JP-A No. 8-75152, ED described in JP-A-58-190952
Chelating agents such as TA and NTA, JP-A-59-12133
Description in Publication No. 6 1) [Co(NHs)s ICL, C
Complexes such as oCl2.61120, JP-A-5O-5J32
Sodium flukylnaphthalene sulfonate described in Publication No. 4,
N-tetradecyl-N,N-nohydroxyethylbetaine and other nonionic surfactants such as tetramethyldecynediol described in 7Niobis, p-dimethylami7methylboristyrene described in JP-A No. 55-95946. Cathonic polymers such as quaternized methyl chloride, amphoteric polymer electrolytes such as the copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, JP-A-57-19295
Reducing inorganic salts such as sodium sulfite described in Publication No. 2, non-fi such as lithium chloride described in JP-A No. 58-59444
IJ tium compounds, organolithium compounds such as lithium benzoate described in JP-A-50-34442, organometallic surfactants containing Si, -Ti, etc. as described in JP-A-59-75255, JP-A-59- Examples include organic boromine compounds described in Japanese Patent No. 84241, quaternary ammonium salts such as tetraalkylammonium oxide described in European Patent No. 101010, and organic solvents such as pencil alcohol ethylene glycol monophenyl ether. or amphoteric surfactant, US Patent ptS4374920
Various conventionally known methods can be used to develop the image-exposed PS plate using the developer described above. Specifically, a method of spraying a developer from a number of nozzles onto the photosensitive layer of the image-exposed PS plate, a method of wiping the photosensitive layer of the 28th plate with a sponge moistened with the developer, and a method of wiping the photosensitive layer of the 28th plate with a wet cloth moistened with the developer. Examples include a method of applying a developer to the surface of the photosensitive layer using a roller. Further, after the developer has been applied to the photosensitive layer of the PS plate in this manner, the surface of the photosensitive layer can be lightly rubbed with a brush or the like. Development conditions may be determined as appropriate depending on the above-mentioned development method. As for the developing solution, the aforementioned negative developing solution and positive developing solution are circulated and reused through their respective paths within the automatic developing machine. At this time, the development of the PS plate is carried out using a common development tank of an automatic developing machine for both the negative 28th plate and the positive 28th plate. Specifically, a developer for negatives and a developer for positives are stored in dedicated developer storage tanks, and development processing is carried out.
When the S plate is a negative type PS plate, a developer for negatives is supplied to a common development processing zone, and when it is a positive type 28 plate, a developer for a common development tank is supplied. A side exchange valve may be provided in the recovery path of the used developer so that the negative and positive developer flows back to their original storage tanks. As an example of the above-mentioned treatment process, for example,
The method described in JP-A-151401 can be mentioned. In the present invention, it is necessary to identify the type of PS plate in order to change the developer depending on the type of PS plate to be processed. There are two methods for identifying the type of PS plate to be developed: an artificial method and an automatic method. Examples of the artificial method include a method of identifying by button operation. Automatic methods include, for example, optically measuring and identifying the optical density of the photosensitive layer or measuring the spectral absorption of the photosensitive layer, or electrically measuring the impedance of the photosensitive layer, or magnetically determining the optical density of the photosensitive layer. Examples include a method of reading a signal stored in a memory element such as a card, or a method of reading a signal stored in a bar code. Further, the developer replenisher may be replenished in accordance with the exhaustion of the developer due to the development process of these 28 plates or the absorption of carbon dioxide in the air. Various conventionally known developer replenishers can be used, and various conventionally known methods can be used to replenish the developer replenisher. The lithographic printing plate that has been subjected to the development process is washed with repeatedly used washing water. The water used for washing is collected in a tank etc. and used repeatedly, but when using it, it is also possible to replenish unused washing water as appropriate, or to use methods such as supplying it to the plate in parallel. ,
From the viewpoint of saving water, it is preferable to circulate and use only the recovered liquid. The washing method involves preparing a certain amount of washing water in a tank connected to an automatic developing machine, and installing a circulation device that collects the washing water once supplied onto the PS plate and supplies it again onto the PS plate. is particularly preferred. The amount of liquid supplied onto the PS plate is 5 per m2 of PS plate to be processed.
00J to 10Q are preferred, and 2Q to 5 are particularly preferred. Methods of supplying washing water onto the PS plate include: / Spraying the processing liquid from a drain or shower pipe, etc. Wiping the plate surface of the 28th plate with a sponge moistened with washing water; Examples include a method of applying with a roller or the like. Moreover, only one method of supplying the washing water may be used, or two or more methods may be used in combination. Further, the plate surface of the 28 plate can be lightly rubbed with a rubbing member such as a brush after or while being supplied. Further, these rubbing members and the above-mentioned supply means may be integrated. In the present invention, one dedicated washing water may be used for each of the negative PS plate and the positive 98 plate, but washing water between points may be used to simplify the structure and operation of the automatic developing machine. It is preferable to use The washing water used in the present invention may be water such as tap water or pure water, but may also contain small amounts of complexing agents, acids, salts, surfactants, and the like. Examples of the complexing agent used in the present invention include E
DTA (ethylenenoaminetetraacetic acid) and its salts, NTA
trilotriacetic acid) and its salts, cyDTA (cyclohexanediaminetetraacetic acid) and its salts, HEDTA (hydroxyethylethylenenoaminetriacetic acid) and its salts, EH
PG (ethylene and su(hydroxyphenylglycine))
] and its salts, amino/carboxylic acids and their salts such as N-hydroxyethylglycine and its salts, \C00Na CM OS (N a OOCCH20CHCH2CO
ONa) Low molecular weight carboxylic acid salts such as 0ONa, HCA (NaoOCCH2CCH2COONa)
, OOH Hydroxycarboxylic acids and their salts such as citric acid and its salts, sodium maleate-sodium acrylate copolymer, sodium acrylate, sodium moo-methacrylate copolymer, sodium polyacrylate, sodium polymaleate, poly- Polymer electrolytes such as sodium hydroxyacrylate, sodium polyitaconate, phosphoric acid esters such as phytic acid and its salts, polyphosphates such as sodium hexametaphosphate, and the like. The polymer electrolyte preferably has a molecular i of 80,000 or less. Among the complexing agents in the present invention, polydentate ligands including -dentate ligands are preferred, so-called chelating reagents, and chelating reagents that form water-soluble chelate compounds are particularly preferred. Further, those having a group consisting of a carboxyl group and/or a salt thereof, particularly those having 3 or more and 800 or less are preferable. As the salt, sodium salt and potassium salt are preferred. Preferred complexing agents in the present invention include E
Examples include DTA and its salts, NTA and its salts, CyDTA and its salts, CMT, 0MO81CA1 sodium hexametaphosphate. In the present invention, one kind or a combination of two or more kinds of complexing agents can be used. The content of the complexing agent in the washing water is 0.01% by weight or more, especially 0.01 to 10% by weight.
is preferred, and 0.003 to 5% by weight is most preferred. The washing water used in the present invention may further contain acids such as acetic acid, boric acid, nitric acid, phosphoric acid, or water-soluble alkali metal salts thereof. These acids and salts may be used alone or in combination of two or more. In particular, when the developer is alkaline, it is preferable to include it as a pH value filter. The washing water used in the present invention may further contain anionic surfactants, such as ethylene glycol,
It may also contain a humectant such as glycerin or polyethylene glycol. The pH value of the washing water used in the present invention is preferably 5 to 8. The printing plate obtained by the processing method of the present invention may then be subjected to treatment with a desensitizing liquid, a treatment with an aqueous solution containing a surfactant, a treatment with a developing ink, and a correction with a correction agent, as necessary. can. The method of the present invention includes:
The above treatment is particularly effective when treated with a desensitizing solution or an aqueous solution containing a surfactant. The desensitizing agent that can be used in the present invention contains a water-soluble polymer compound and water as essential components, and if necessary, a surfactant, an acid,
It can contain water-soluble salts, wetting agents, organic solvents, preservatives and fungicides, and the like. The water-soluble polymer compounds contained in the desensitizing agent used in the present invention include natural polymers, semi-natural polymers, and synthetic products. Natural polymers include starches such as Japanese starch, potato starch, corn starch, wheat starch, and corn starch; those obtained from algae such as calanonan, laminaran, seaweed mannan, funori, Irish moss, agar, and sodium alginate; Vegetable mucilages such as mannan, quince seed, bectyl, tracanthum, karaya gum, xanthine gum, guarving gum, locustvin, gum arabic, carob and benzoin gum, homopolysaccharides such as dextran, glucan and levan; Examples include microbial mucilages such as heteropolysaccharides such as succinoglucan and xanthan gum, proteins such as glue, gelatin, casein, and colladen sugar. In addition to alginate propylene glycol ester, semi-tempered products (semi-synthetic products) include viscose, methylcellulose, ethylcellulose, methylethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, hydroxypropylethylcellulose, and hydroxypropylmethylcellulose 7 tallate. Examples include cellulose derivatives such as and processed starch. Modified starches include roasted starches such as white dextrin, yellow dextrin, and British gum, enzyme-modified dextrins such as enzyme dextrin and shardin boodextrin, fermented starch as shown in solubilized starch, and fermented starch as shown in dialdehyde starch. , pregelatinized starches such as modified pregelatinized starches and unmodified pregelatinized starches;
Phosphate starch, fatty starch, sulfate starch, nitric acid 1Plh ÷ 1~no LA/~no Tsukumisaki%ll・rTthe,
Esterified starches such as x, +-ζ-acid starches, etherified starches such as carboxyalkyl starches, hydroxyalkyl starches, sul7-oalkyl starches, allyl starches, bennor starches, carbamylethyl starches and cyfurkylamialkyl starches; methylol cross-linked starch,
crosslinked starches such as hydroxyfurkyl III starch, phosphate crosslinked starch and dicarboxylic acid crosslinked starch;
Starch polyacrylamide copolymer, starch polyacrylic acid copolymer, starch polyvinyl acetate copolymer,
Starch polyacrylonitrile copolymers, cationic starch polyacrylic ester copolymers, cationic acid starch vinyl polymer copolymers, starch polyacrylonitrile copolymers, starch polyethylene oxide copolymers, etc. Examples include starch graft copolymers. Synthetic products include E') H: - Rual:
7-ru other partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol) IJ Ze II l-
P Nil J car) 1, Ko-son 11,, LP l Suga 1. J
-+ -Modified polyvinyl alcohols such as thyl ether and polyvinyl isobutyl ether, sodium polyacrylate, partially saponified polyacrylic esters, partially saponified polyacrylic ester copolymers, polymethacrylates and polyacrylamides. Acrylic acid derivatives and polymethacrylic acid derivatives, polyethylene glyfur, polyethylene oxide, polyvinylpyrrolidone, copolymers of polyvinylpyrrolidone and vinyl acetate-F, carboxyl vinyl polymers, styrene maleic acid copolymers, styrene crotonic acid copolymers, etc. can be given. Among these, those obtained from algae, vegetable mucilages, cellulose derivatives, modified starches, alginate propylene glycol esters, and synthetic products are preferably used because they have good film-forming properties on printing plates. More preferably, sodium alginate, alginate propylene glycol ester, tiger canth gum, locust Bingham, guarbing gum, gum arabic, methylcellulose, ethylcellulose, hydroxyethylcellulose,
Hydroxypropyl methylcellulose, carboxymethylcellulose, roasted starch, oxygen-modified dex) phosphorus, oxidized starch, acid-decomposed starch, pregelatinized starch, polyethylene glyfur, polyvinyl alcohol,
They are modified polyvinyl alcohol, polyacrylic acid derivatives, polymethacrylic acid derivatives, polyethylene oxide, and polyvinylpyrrolidone. Vegetable mucilages, amyl derivatives, and modified starches are preferably used because they have strong protective colloidal properties in emulsions. roasted starch, oxygen-modified dextrose)
+7 starch, oxidized starch, acid-decomposed starch, and pregelatinized starch are preferably used because they do not cause a decrease in the oil sensitivity of the image area. M&arsenic derivatives are preferred because they have high emulsion stability due to their thickening effect. Carboxymethyl cellulose, gum arabic, tracanthum, locust Bingham and guarbing gum are preferred because they have high non-fatty properties in non-image areas. Among them, gum arabic is preferred because it has extremely high oil-insensitivity in non-image areas. These water-soluble polymer compounds can be used alone or in combination of two or more. In particular, two or more water-soluble materials selected from the group consisting of sodium alginate, propylene glycol alginate, gum arabic, dextrin, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, polyethylene glycol, polyvinyl alcohol, and polyvinylpyrrolidone. Use of a polymer compound in combination is preferred from the viewpoints of uniform film formation, prevention of deterioration of oil sensitivity in image areas, protective colloid performance of the emulsion, and emulsion stability of the emulsion. Products containing gum arabic and combined with one or more other water-soluble polymer compounds can increase the hydrophilicity and desensitization of non-image areas without reducing the oil sensitivity of image areas. Preferably, the ratio of gum arabic to the total amount of other water-soluble polymer compounds is preferably 4:1 to 1:15, more preferably 2:1 to 1:8. Among them, the combination of gum arabic and dextrin is most preferred. The water-soluble polymer ranges from about 1% to about 60% by weight, more preferably from 2% to about 40% by weight, and even more preferably from 8% to about 1% by weight based on the total weight.
Used at ~25% by weight. It is preferable that the desensitizing agent used in the present invention further contains a surfactant. Examples of such surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyrene phenyl ethers, polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, penta Erythritol fatty acid partial esters, propylene glycol monofatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, Polyoxyethylenated castor oil, polyoxyethane glycerin resin
, N,N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethylamine fatty acid esters, nonionic surfactants such as trialkylamine oxides, fatty acid salts, avicenoates, hydroxyalkanesulfones Acid salts, alkanesulfonates, dialkylsulfosuccinates, linear alkylbenzenesulfonates, branched chain alkylbenzenesulfonates, alkylnaphthalenesulfonates,
Alkylphenyloxypolyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether mM, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamide disodium salts, petroleum sulfonates, 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, sulfuric acid mono/glyceride sulfate ester salts, polyoxyethylene alkyl phenyl ether sulfate ester salts, Oxyethylene styryl phenyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, styrene-
Partially saponified maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, anionic surfactants such as naphthalene sulfonate formalin condensates, alkylamine salts, quaternary Examples include cationic surfactants such as ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives, and amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfate esters, and imidazolines. It will be done. Among the surfactants listed above, polyoxyethylene can also be read as polyoxyalkylene such as polyoxymethylene, polyoxypropylene, and polyoxybutylene.
These surfactants are also included, and the same applies in the following description. Among these, polyoxyethylene alkyl ethers, polyoxyethylene alkyl 722 ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid moiety Esters, pentaerythritol fatty acid partial esters, propylene glycol mono-fatty acid esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene glycerin fatty acid partial esters, polyethylene glycol fatty acid esters, polyoxyethylated castor oil , dialkyl sulfonate (acid salts, alkyl benzene sulfate, t, em
u, alkylnaphthalene sulfonates, alkyl sulfate ester salts, and polyoxyethylene alkylamine salts are preferable because, like the lipophilic substances mentioned above, they also have the function of suppressing a decrease in the oil sensitivity of the image area of a lithographic printing plate. Polyoxyethylene alkylphenyl ethers, titanium polyethylene 7. Nyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, polyethylene glycol fatty acid DelN esters, dialkyl sulfo(acids), alkyl sulfate esters Salts are particularly preferred, and among nonionic surfactants, those with an HLB of 14 or less are preferred because they have a high effect of stabilizing emulsions, and those with an IILB of 11 or less are preferred.These surfactants may be used alone or in combination. Two or more types can be used in combination, but in particular, combinations of alkylphenyl type nonionic surfactants such as polyoxyethylene alkylphenyl ethers and polyoxypropylene dialkyl 722yl ethers and dialkyl sulfosuccinates, Combinations of fatty acid ester type surfactants and dialkyl sulfosuccinates, and combinations of furkylphenyl type nonionic surfactants, fatty acid ester type surfactants, and dialkyl sulfosuccinates (acids) may cause desensitization. It is preferable because it is not only easy to emulsify during production, but also has the effect of suppressing the deterioration of oil sensitivity in the image area.Furthermore, when fatty acid ester type surfactants and noalkyl sulfosuccinates are used together, When a mixture of at least two types of fatty acid ester type surfactants (for example, a mixture of sorbitan more oleate and sorbitan monolaurate) is used as the fatty acid ester type surfactant, the emulsion is stabilized when developer components are mixed. The surfactant is preferably used in an amount of about 0.5 to about 2 with respect to the total amount of ilX for desensitization.
It can be used in a range of 0% by weight, more preferably 1 to 10% by weight. It is preferable that the desensitizing agent used in the present invention further contains an acid. The main purpose of the acid contained in the desensitizing agent is to adjust the pH of the desensitizing agent before use to an acidic range, preferably in the range of pH 1 to 5, more preferably in the range of pH 1.5 to 3. It is used. Inorganic acids such as phosphoric acid, pyrophosphoric acid, polyphosphoric acid, monosodium phosphate, boric acid, hydrochloric acid, sulfuric acid, nitric acid, or e.g. succinic acid, oxalic acid, citric acid, maleic acid, lactic acid, P-)/reninsulfonic acid , benzenesulfonic acid and the like can be used, and these can be used alone or in combination of two or more. Among these, phosphoric acid and succinic acid are particularly preferred. The amount of acid to be used may be such that the pH of the desensitizing agent is in the acidic range, and is approximately 0.01 to 5% by weight. It is preferable that the desensitizing agent further contains a water-soluble salt as a buffering agent. This makes the non-image area more hydrophilic when the desensitizing agent is applied to the lithographic printing plate. For details on buffering agents, see, for example, "Chemistry Handbook Basics Part ■", Nippon Kagaku Kinyo, February 20, 1971, 5th edition, published by Maruzen Co., Ltd., 13
12 to 1320, and these can be applied as is. Suitable water-soluble salts include salts of inorganic acids such as molybdic acid, boric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, as well as acetic acid, oxalic acid, tartaric acid, benzoic acid, succinic acid, citric acid, malic acid, lactic acid, and tannin. Acids include salts of organic acids such as p-)reninsulfonic acid. More preferred salts are water-soluble alkali metal salts and ammonium salts, and particularly preferred are molybutates such as ammonium molybutate, nitrates such as potassium nitrate, sulfates, phosphates such as sodium phosphate, potassium tetrapolyphosphate, sodium trimetaphosphate, etc. polyphosphates, oxalates such as sodium oxalate, tartrates such as potassium tartrate, succinates such as sodium succinate, and citrates such as ammonium citrate. These water-soluble salts can be used alone or in combination of two or more, and the total amount of salts is preferably about 10% by weight or less based on the total amount fl of the desensitizing agent from the viewpoint of stability of the emulsion. More preferably 0.
It is used in a range of 0.01 to 6%. Further, the pH of the desensitizing agent is preferably between 1 and 10, and preferably between 1 and 8 in order to suppress a decrease in the sensitivity of the image area. Most preferably, the desensitizing effect of non-image areas is high when the pl (pl) is 2.0 to 6.0. This not only improves the emuldicin stability of the desensitizing agent, but also improves Wllhta, tr.
sdl, FNkMh79%trt-1-JLM, 1-1
−+, −−−. Wear. Preferred lipophilic materials include lipophilic resins used as vehicles for lithographic printing inks. Specifically, phenol formaldehyde resins, cresol formaldehyde resins, t-butylphenol formaldehyde resins, and other 7-volume phenol I resins, xylene resins made by condensing phenol and xylene with formaldehyde, and phenol and mesitylene condensed with formaldehyde. Resin, polyhydroxystyrene, brominated polyhydroxystyrene, cashew resin, partially esterified copolymer of styrene and maleic anhydride, melamine resin, alkyd resin, polyester resin, epoxy resin, rosin, hydrogenated rosin, rosin ester, etc. Examples include petroleum resins such as modified rosin and giltnite, among which /borac type phenolic resins, rosin and modified rosin are preferred.Other preferred lipophilic substances include plasticizers, fatty acids, fatty oils and waxes. Preferred plasticizers include dibutyl phthalate, civebutyl 7
heptatalic acid noesters such as di-n-octyl heptalate, di-(2-ethylhexyl) heptalate, tunnonyl heptalate, nobusylphthalate, silacryl heptalate, butylbenzyl heptalate, e.g. dioctyl azelate, dioctyl Adipate, butyl glycol adipate, dibutyl sebacate, sea (2-
Aliphatic dibasic acid esters such as ethylhexyl) sebacate and nooctyl sebacate, epoxidized triglycerides such as epoxidized soybean oil, such as tricresyl 7-mose 7-ate, trioctyl 7-mose 7-2-t,
Included are phosphoric acid esters such as trischlorethyl heptagonate, benzoic acid esters such as benzyl benzoate. Among these, particularly preferred are dioctyl adipate, dibutyl sebacate, and dioctyl azelate, which are odorless and highly safe. Preferred fatty acids include caproic acid, enanthic acid, caprylic acid,
herargonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecyl acid, valmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lig/selenic acid, cerotic acid, heptacanoic acid, Saturated fatty acids such as montanic acid, tarylic acid, lafuselic acid, isovaleric acid, acrylic acid, crotonic acid, isocrotonic acid, undecylic acid, oleic acid, elitusnic acid, cetoleic acid, erucic acid, brassic acid,
Unsaturated fatty acids include sorbic acid, linoleic acid, lylunic acid, arachidonic acid, propiolic acid, stearolic acid, sardine acid, tarylic acid, and licanoic acid. Preferred waxes include carbanara wax, beeswax, spermaceti wax, insect white wax, wool wax, shellac wax, and the like. The desensitizing agent may further contain a wetting agent. Thereby, the property that the hydrophilic component such as the water-soluble polymer compound of the desensitizing agent spreads appropriately to the non-image area of the lithographic printing plate and the flexibility of the film can be improved. Preferred examples of such wetting agents are polyhydric alcohols, specifically ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, bentanol, hexylene fuglycol, tetraethylene glycol, polyethylene glycol, dipropylene. Examples include glycol, tripropylene glycol, glycerin, sorbitol, and pentaerythritol, with glycerin being particularly preferred. The wetting agent is about 0.5 to about 10% by weight based on the total weight of the desensitizing agent of the present invention.
, more preferably in a range of 1 to 5% by weight. The desensitizing agent can contain an organic solvent. Preferred organic solvents are poorly soluble in water, such as evaporate turpentine, xylene, toluene, benzene, n-hebutane,
Solvent naphtha, kerosene, mineral spirits, petroleum distillates with a boiling point of about 20°C to about 250°C, ketones such as cyclohexanone, halogenated hydrocarbons such as dichloroethylene, ethylene glycol monomethyl ether,
These include ethylene glycol ethers such as ethylene glycol monophenyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether. These solvents may be present in an amount of about 0.05 to about 10% by weight, more preferably 0.5 to about 10% by weight, based on the total weight of the desensitizing agent.
It is used in a range of 5 weight and 1%. The unfattening agent further includes sorbic acid, preservatives such as ethyl p-oxybenzoate, fungicides, propyl gallate, 2,6
It is preferable to contain an antioxidant such as -di-t-butyl-4-ethylphenol or 2,6-not-t-butyl-4-methylphenol. The preservative effect of the desensitizing agent can be obtained by adding a small amount of these preservatives, antifungal agents, and antioxidants, but preferably o, o
oi to 5% by weight. The desensitizing agent used in the present invention may be an emulsion-type desensitizing agent, a suspension-type desensitizing agent, or a non-emulsion desensitizing agent by appropriately selecting the surfactant, lipophilic substance, etc. to be contained. M-type non-suspension type desensitizers can be produced in any way, but emulsion type desensitizers and suspension type desensitizers prevent a decrease in the oil sensitivity of the image area of a lithographic printing plate. It is preferably used because of its high performance. Furthermore, in order to improve the preparation efficiency and transport efficiency of the desensitizing agent, a method can also be used in which the components are prepared at high concentrations and diluted with water to a desired concentration before use. In addition, the surfactants used in the aqueous solution containing a surfactant used in the post-treatment of the lithographic printing plate obtained by the method of the present invention include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers,
polyoxyethitane 1,1 stylphenyl ether,
Polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial ester, sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester , polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylated castor oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid jetanolamides, N, N- Nonionic surfactants such as bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, trialkylamine oxide fatty acid esters, trialkylamine oxides, fatty acid salts, avicenoates, hydroxyalkanes Sulfonates, alkanesulfonates, dialkyl sulfosuccinate ester salts, linear alkylbenzene sulfonates, flukylnaphthalene sulfonates, alkylphenoxypolyoxyethyleneprobyl sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-
N-oleyl taurine sodium, N-furkylsulfosuccinic acid mo/amide disodium salts, petroleum sulfonates, sulfated castor oil, sulfated tallow oil, sulfate ester salts of fatty acid alkyl esters, alkyl sulfate ester salts, polyoxyethylene alkyl Ether sulfate ester salts, fatty acid monoglyceride sulfate [M, Vol.
J oxyethitane alkyl phenyl ether sulfate ester salts, polyoxyethylene styrylphenyl ether sulfate ester [i, furkyl phosphate ester salts, polyoxyethylene alkyl ester phosphate ester salts,
Polyoxyethylene alkyl phenyl ether phosphate ester salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensates, etc. 7Nionic surfactants, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, cationic surfactants such as polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric acid Examples include amphoteric surfactants such as esters and imidazolines. Among the surfactants listed above, polyoxyethylene includes polyoxymethylene, polyoxypropylene,
It can also be read as polyoxypropylene such as polyoxybutylene, or polyoxyalkylene such as polyoxybutylene, and these surfactants are also included, and the same applies in the following description. Among these, polyoxyethylene alkyl ethers,
Polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl 7enyl ethers, polyoxyethylene polyoxybrobylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene Glycol monofatty acid esters, 17oxyethitane sorbitan fatty acid partial esters, polyoxyethylene glycerin fatty acid partial esters, polyethylene glycol fatty acid esters, polyoxyethylated castor oil, dialkyl sulfosuccinates, alkylbenzene sulfone rl 1mM, alkylnaphthalene Sulfonates, alkyl sulfate ester salts,
Fatty acid salts, alkyl phosphate ester salts, naphthalene sulfonate formalin condensates, polyoxyethylene alkylamine salts, alkylamine salts, and quaternary ammonium salts also tend to suppress the decrease in oil sensitivity in the image area of lithographic printing plates. Among them, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, Particularly preferred are pentaerythritol fat D a W = fractionated esters, propylene glycol mo/fatty acid esters, polyethylene glycol fatty ministers, dialkyl sulfosuccinate ester salts, alkyl sulfate ester salts, and alkylbenzene sulfonate salts. The most preferred are alkylbenzene sulfonic acid salts and dialkyl sulfosuccinate ester salts, which have strong dispersing power. The above surfactants can be used alone or in combination of two or more, and are about 0.1% to about 20% by weight, more preferably 0.5% to 10% by weight in an aqueous solution.
Used in a range of % by weight. The pH of the aqueous solution containing the surfactant in the present invention is 1 to 1.
2 is preferred. In order to adjust the aqueous solution to this pH, it is preferable to contain either or both of an acid and a water-soluble salt as a buffer. As a result, when the aqueous solution is applied to a lithographic printing plate, the developer component remaining on the plate is neutralized, making the non-image area more hydrophilic. Details of buffering agents are described, for example, in "Chemistry Handbook I! Edition ■", Nippon Kagaku Complete Edition, February 20, 1972, 5th edition, published by Maruzen Co., Ltd., 1312-1320, and these can be applied as is. can do. Suitable acids and water-soluble salts include molybdic acid, boric acid,
Acids such as inorganic acids such as nitric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid, and water-soluble organic acids such as acetic acid, oxalic acid, tartaric acid, benzoic acid, succinic acid, citric acid, malic acid, lactic acid, and p-)luenesulfonic acid. and its salt. More preferred salts are water-soluble alkali metal salts and ammonium salts, and particularly preferred are molybdates such as ammonium molybdate, phosphates such as sodium phosphate, polyphosphates such as potassium tetrapolyphosphate and sodium trimetaphosphate, and sodium oxalate. These are oxalates such as, tartrates such as potassium tartrate, succinates such as sodium succinate, and citrates such as ammonium citrate. These acids and water-soluble salts can be used alone or in combination. A more preferable pH of the aqueous solution containing the surfactant 1 is 1.
It is 5-8. The most preferable pH is 2.0 to 6.5, in which case the non-image area of the lithographic printing plate has a higher ability to become fat-free. In addition, in the plate making method of the present invention, developer components are brought into the aqueous solution, so in order to neutralize this, salt and/or acid is added in advance in an amount corresponding to the planned processing area of 28 plates. It is preferable to leave it there. The amount of acid and salt added to the aqueous solution is not particularly limited, but the total amount of acid and salt is about 10% based on the total weight of the aqueous solution.
It is preferably less than % by weight. More preferably, it is used in a range of 0.01 to 6% by weight. The aqueous solution containing the surfactant in the present invention further includes sorbic acid, preservatives such as ethyl p-oxybenzoate, fungicides, propyl gallate, 2.6-cythylbutyl-4-ethylphenol, - An antioxidant such as butyl-4-methylphenol may be contained. By adding a small amount of these preservatives such as preservatives, antifungal agents, and antioxidants, it is possible to prevent deterioration in quality due to storage of the aqueous solution, but the preferable addition amounts are o, oo, etc.
t~5% by weight. It is preferable that the aqueous solution containing the surfactant in the present invention contains a lipophilic substance. As a result, the image area of the lithographic printing plate shows higher oil sensitivity, which not only makes it easier to build up the developing ink, but also makes it easier to apply the plate surface protectant after treatment with the aqueous solution. It is possible to strongly suppress the decrease in oil sensitivity. Preferred lipophilic substances include organic carboxylic acids having 5 to 25 carbon atoms, such as oleic acid, lauric acid, valeric acid, nonylic acid, capric acid, mystylic acid, valmitic acid, castor oil, and the like. These lipophilic substances can be used alone or in combination of two or more. The lipophilic substance contained in the surfactant-containing aqueous solution in the present invention is 0.005% by weight based on the total amount.
from about 10% by weight, more preferably from 0.05 to 5% by weight
is within the range of EXAMPLES The present invention will be specifically explained below using Examples.

【Example】

3 parts by weight of esterified product of 1,2-noacyto-5-sulfonyl chloride and resorcinol-benzaldehyde resin (described in Example 1 of JP-A-58-1044), cresol novolak resin , and 0.12 parts by weight of Victoria Pure Blue BOH (a dye manufactured by Hodogaya Chemical Industry Co., Ltd.) were dissolved in 100 parts by weight of methyl cellosolve to prepare a photosensitive solution. A grained aluminum plate with a thickness of 0.3+am is anodized in sulfuric acid to create an oxide film of approximately 2.5g/lo2,
After thorough washing and drying, the above photosensitive solution was applied thereon and dried to obtain a positive type 28 plate having a photosensitive layer weight of about 2.5 g/II+2. In addition, a copolymer of rose hydroxyphenyl methacrylamide, acrylonitrile, ethyl acrylate, and methacrylic acid (molar ratio is 8.5:24:60.5 in the above order)
5.0 parts by weight Hexafluorophosphate of a condensate of p-noazinophenylamine and paraformaldehyde...0
．． 5 parts by weight Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Industry Co., Ltd.) A photosensitive solution prepared by dissolving 0.1 part by weight in 100 parts by weight of methyl cellosolve was prepared and grained to a thickness of 0.24 mm. An aluminum plate was anodized in sulfuric acid to form an oxide film of about 2 g/a+2, washed thoroughly, immersed in an aqueous sodium silicate solution, thoroughly washed with water, and dried to form a coating with the above composition on the support. A photosensitive solution was applied and dried to obtain a negative type 28 plate having a photosensitive layer of approximately 1.8 g/m2.The resulting positive type and negative type 28 plates were 1003 x 800.
A large number of pieces each cut to a size of 1 were prepared. The positive 28 plate was then exposed through the transparency for 60 seconds from a distance of 80 cm using a 2KW metal halide lamp. The negative 28 plate was exposed for 30 seconds under the same conditions through a transparent negative. On the other hand, for positive type 28 plates, potassium silicate aqueous e(
Using a potassium hydroxide aqueous solution (48% aqueous solution) and pure water, the molar ratio of Sio2 and Sio2 to 20 ((Sin2)/(
A developing solution with K2O)) of 1.78 and a molar concentration of 20 of 3.90 mol/Q and the molar ratio of silicic acid to potassium (
S io2/ K2O) is 0.88-Kz○ molar concentration is 7.78 mol/! 1 of developer replenisher was prepared. A developing solution for negative 25th plate having the following composition was prepared. yl・Yellow ethylene glycol monophenyl ether 40 parts by weight Noethanolamine 10 parts Sodium lobetylnaphthalene sulfonate 12 parts by weight Antifoaming agent (SM-5512 made by Renlin Co., Ltd.) 0
．． 05 parts by weight Water 937 parts by weight t
An automatic developing machine shown in the JSi diagram was prepared. In FIG. 1, 1 is the development process l! I! tank, 2 is a conveyance roller, 3 is a squeezing roller, 4 is a receiving roller, 5 is a brush roller,
6 is a positive developer storage tank, 6' is a positive developer replenisher storage tank, 7 is a positive shower pipe, 8 is a cylinder pump, 8' is a positive developer replenisher pump, 9 is a negative developer A storage tank, 10 a negative shower pipe, 11 a negative pump, and 12 a flow path switching valve. 13 is a washing tank, 14 is a washing water pump, 15 is a washing water storage tank, 1
6 is a water washing layer shower pipe. 19 is a desensitizing treatment tank, 20 is a desensitizing liquid pump, 21 is a desensitizing liquid storage tank, and 22 is a desensitizing liquid shower pipe. Reference numeral 17 is a light reflection sensor for identifying the type of PS plate to be processed, and 18 is a control device for controlling pump operation and flow path switching valves based on the type information. The developer replenisher was charged in an amount of 20 times each into the corresponding developer storage tank of the automatic processor, and 30 r1 of the developer replenisher was charged into the developer replenisher storage tank. Washing water 20Q was charged into the storage tank 15, and desensitization treatment liquid 129 having the following composition was charged into the storage tank 21, respectively. Water 170 parts (parts by weight) Gum arabic 5.5 Dextrin (
Enzyme denaturation) 23 85% phosphoric acid 1.1 96% sodium hydroxide 0.25 // Sodium dilauryl sulfosuccinate 3 Sorbitan monolaurate 3 Sorbitan moolae 3 Castor oil 3 2-ethylhexyl alcohol 2 The pH of this desensitizing solution was 2.65. The temperature of the developer was maintained at 25° C. for both negative and positive samples, and the development time was 40 seconds. In addition, 21 mQ of positive developer replenisher is replenished every time one plate is developed.
Replenishment was made at a rate of 35+aQ per hour, regardless of the development process. The selection of these negative or positive developing solutions is performed by the control device 18 based on the product type information from the light reflection sensor 17. Further, the control device 18 controls the developer supply pump 8.
．． The operations of 11, the desensitizing liquid supply pump, 14 the developer replenisher pump, and 8' are controlled, and the switching of the switching valve 12 is controlled. In this way, the exposed 23rd negative plate and the 28th negative plate were processed alternately for 375 plates each for a total of 750 plates. When printing, the ink adhesion to the image area was good, and for all plates, the ink was completely transferred to the paper within 20 sheets, and a good print was obtained.Also, during this time, the desensitizing liquid was hardly fatigued and was replaced. It was possible to use it continuously without needing it. Comparative Example 1 Using the same device as in Example 1, the washing water tank 13 was used as a desensitizing treatment tank [15 was filled with the same desensitizing solution as in Example 1. Also, the tank 19 was not used and the squeegee roller 23 was removed.The exposed P was prepared in the same manner as in Example 1 in other respects.
Processed the S version. 230 negative printing plates and 230 positive printing plates were each processed. was later processed. When the negative and positive printing plates were printed using a printing press, there were areas where the ink was deposited on the non-image areas of the positive printing plates, and good printed matter could not be obtained. Comparative Example 2 The same process as in Example 1 was carried out, except that a drainage port was provided at the bottom of the washing tank of the apparatus in Example 1, and the shower pipe 16 was configured to be able to continuously supply city water. I did it. The city water supply was approximately 5 Q/man. Positive and negative PS plates were processed alternately with 375 plates each for a total of 750 plates, and 23 positive and negative plates each treated with Rf& were printed on a printing machine, and the positives were within 20 sheets and the negatives were 30 sheets.
The ink was completely transferred to the paper within one sheet and a good printed matter was obtained. However, the amount of washing water used reached approximately 37,009, and the same amount of wastewater was generated that required purification treatment. [Effects of the Invention] According to the present invention, it has become possible to mix a negative PS plate and a positive 28 plate in the same automatic development process, and to suppress the generation of waste water to an extremely small amount. The resulting lithographic printing plate has good printability and is also excellent in adaptability to post-processing such as desensitization treatment, treatment with an aqueous surfactant solution, and correction.

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view of the automatic developing machine used in the above embodiment.

Claims (1)

[Claims] Using an automatic processor, negative photosensitive lithographic printing plates and/or
Alternatively, in a method for processing a photosensitive lithographic printing plate, in which a positive-working photosensitive lithographic printing plate is automatically conveyed and developed in the same development tank of the automatic developing machine, the negative-working and/or
Alternatively, positive-working photosensitive lithographic printing plates are developed with dedicated developers that are stored in separate developer storage tanks and used in circulation, and then washed with the same washing water that is used in circulation. Characteristic processing method for photosensitive lithographic printing plates.