JPS6236673A - Method for processing photosensitive lithographic printing plate - Google Patents

Abstract

PURPOSE:To commonly develop PS plates of both negative and positive type types and to provide a substantial desensitization characteristic to a non-image part without rinsing by conveying the PS plates of the negative and positive types, developing the plates with developing solns. to be exclusively used according to the types thereof and processing the plate surfaces with one kind of an aq. soln. contg. a surface active agent. CONSTITUTION:The developing solns. for positive and negative are charged into developing solns. storage tanks 6 and 9 for positive and negative, respectively and the soln. contg. the surface active agent is charged into a surface active agent soln. storage tank 15. The kinds of the positive or negative type PS plates which are alternately conveyed by 35 plates each by conveying rollers 2 are detected by a light reflection sensor 21. Pumps 8, 11 for positive and negative, a surface active agent soln. supply pump 14, a developing replenisher pump 8' and a flow passage selector valve 12 are controlled to send the developing soln. meeting the PS plates to a developing tank 1 and the surface active agent soln. to a surface active agent soln. processing tank 13. The plates are developed while the replenisher is replenished from the developing soln. storage tank 6' for positive at every development process of one plate, then the plates are processed with the surface active agent soln.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for processing a photosensitive lithographic printing plate, and more specifically, a method that does not include a water washing step after the development step of a negative 28 plate and/or a differential 928 plate. This invention relates to a method for processing lithographic printing plates.

[Conventional technology]

Negative photosensitive lithographic plate, printing plate (
When processing a positive photosensitive lithographic printing plate (hereinafter simply referred to as a negative 28 plate) and a positive photosensitive lithographic printing plate (hereinafter simply referred to as a differential 928 plate), it is necessary to replace the developer each time depending on the type of PS plate. A problem arises in that the efficiency of the system is significantly reduced. As a countermeasure to this,
Publication No. 1 states that a developer for a negative PS plate and a developer for a positive PS plate are each stored in a dedicated storage tank, and when developing a PS plate, the developer corresponding to the PS plate is supplied and developed. However, a method for obtaining a printing plate by washing with water after development is disclosed. - However, washing with water after development leads to wastage of water and also causes problems such as environmental pollution due to wastewater, which is not preferable. As a development treatment that eliminates the water washing step, Japanese Patent Application Laid-Open No. 54-8002 discloses a method in which a PS plate is desensitized immediately after the development treatment. This method has the problem that it is difficult to apply development ink to the plate obtained and to make corrections.

As a method for obtaining a plate that is easy to make corrections such as additions and erasures, and to apply developing ink without washing with water, JP-A-55-
Japanese Patent No. 115045 discloses a method in which a PS plate is treated with an aqueous solution containing a surfactant immediately after development without washing with water. However, both negative and bond type P
There has been no conventional PS plate processing method that can process the S plate in parallel, and can also perform correction processing, development ink buildup, etc. without water washing. Moreover, its development was extremely desirable for practical purposes.

An object of the present invention is to provide a method for processing PS plates that can process both negative and positive PS plates in parallel using the same automatic processor and does not generate waste water.

Another object of the present invention is to develop the 28th negative plate and the 28th positive plate in common, so that the 28th negative plate and the 28th positive plate can be developed without the need for a water washing process.
Both the 8th plate and the positive 28th plate can be used for development ink build-up and correction processing under the best conditions, and in addition, the subsequent desensitization process provides sufficient oil for non-image areas without reducing the oil sensitivity of image areas. PS that can give insensitivity
The purpose is to provide a method for processing plates.

Means for Solving Problem r and α] The inventors of the present invention have conducted extensive research to solve the above-mentioned problems, and as a result, have developed a negative-working photosensitive lithographic printing plate and/or a positive-working photosensitive lithographic printing plate using an automatic developing machine. Negative type, in which printing plates are automatically conveyed and stored in separate developer storage tanks and circulated according to the type of photosensitive lithographic printing plate to be processed in the development zone of the automatic processor; Alternatively, a photosensitive method characterized by supplying a developer exclusively for positive-working photosensitive lithographic printing plates onto the photosensitive lithographic printing plate for development processing, and then supplying an aqueous solution containing a surfactant to the plate surface for processing. It has been found that the above objects can be achieved by a method of processing lithographic printing plates.

The present invention will be explained in detail below.

In the present invention, the N-type PS plate is one in which a photosensitive layer whose solubility changes upon irradiation with light is coated on a support, or a soluble layer in which an image-like resist layer is formed by an electrophotographic method or the like. is provided on a support.

Supports used for the above PS plates include paper, plastics (e.g. polyethylene, polypropylene, polystyrene, etc.), laminated paper, aluminum (including aluminum alloys), metal plates such as zinc, copper, etc., and diacetic acid. Films of plastics such as cellulose, cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene polypropylene, zaricarbonate, polyvinyl acetal, etc., paper or plastic films laminated or vapor-deposited with the above metals, aluminum or chrome plating Among these, especially,
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 ffi adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known methods such as brush polishing, ball polishing, electrolytic etching, chemical etching, liquid honing, and sandblasting, and combinations thereof, and preferably brush polishing, electrolytic etching, and chemical etching. Target etching and liquid honing are two methods, and among these, a surface roughening method that includes the use of electrolytic etching is preferable. An aqueous solution containing a salt of or an aqueous solution containing an organic solvent is used, and among these, an electrolytic solution containing hydrochloric acid, nitric acid, or a salt thereof is particularly 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 treatments such as pore sealing and other surface treatments such as immersion in a tempered potassium zirconate aqueous solution can be performed. As a photosensitive substance, its physical and chemical properties change upon exposure or subsequent development processing. For example, a substance that differs in solubility in a developer due to exposure, and Examples of usable materials include those that cause a difference in the adhesive strength between molecules, those that exhibit a difference in affinity for water and oil due to exposure or subsequent development treatment, and those that can form an image area by electrophotography. Typical photosensitive substances include photosensitive diazo compounds, photosensitive acid compounds, compounds with ethylenically unsaturated double bonds, epoxy compounds that polymerize with acid catalysts, and C-0- that decomposes with acids. C
Examples include compounds having - groups.

Examples of the photosensitive diazo compound include an 0-quinonenoasite compound as a positive type compound that changes to be alkali-soluble upon exposure, and an aromatic noazonium salt as a negative type compound whose solubility decreases upon exposure.

Specific examples of 0-quinonediazide compounds include, for example, JP-A Nos. 47-5303, 48-63802°, and 4
No. 8-63803.

No. 49-38701, No. 56-1044, No. 56-
No. 1045, Special Publication No. 41-11222, No. 43-28
No. 403, No. 45-9610, No. 49-17481, U.S. Patent No. 2,797,213 No. 3,0
No. 46,120, No. 3,188,210, No. 3,45
No. 4,400.

No. 3,544,323, No. 3,573.917, No. 3.674.495.

No. 3,785,825, British Patent No. 1,277.6
No. 02, No. 1.251.345, No. 1,267.
No. 005, No. 1,329,888, No. 1.330
．． No. 932, German Patent No. 854,890, etc., and the present invention applies to the 23rd edition in which these compounds were used alone or in combination as photosensitive components. It is possible to apply it preferably.

These light-sensitive components include 0-quinone diat sulfonic acid ester or 0-quinone diat carboxylic acid ester of an aromatic hydroxy compound, and 0-quinone noadi-sulfonic acid or 0-quinone diazide carboxylic acid amide of an aromatic amine/compound. Also included are those in which these 0-quinonediazide compounds are used alone, and those in which they are mixed with an alkali-soluble tH fat and this mixture is provided as a photosensitive layer.

The alkali-soluble resin includes novolac type phenol H resin, and specifically includes phenol formaldehyde resin, cresol formaldehyde resin, phenol cousol mixed formaldehyde resin, cresol xylenol mixed formaldehyde resin, and the like. Furthermore, as described in 'I 1987-125806, in addition to the above-mentioned 7-el resins, terL-butyl 7-el formaldehyde resins having 3 carbon atoms,
A combination of a phenol substituted with a furkyl group of -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 present invention can be applied to a photosensitive layer containing an 0-quinonediazide compound as a photosensitive component in an amount per unit area of at least about 0.5 to 7 g/m''.

There is no particular need to change the image exposure of the positive type 15 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! which is a condensate of diazonium salt and/or p-noadiphenylamine and formaldehyde. I fat, 7-enol salt or fluorocaprate of p-noazinophenylamine described in Japanese Patent Publication No. 52-7364, 3-methoxydiphenylamine-4 described in Japanese Patent Publication No. 49-48001
-Diazo O (fat) consisting of an organic solvent soluble salt of a copolycondensate of noazonium chloride, 4-nitrodiphenylamine and formaldehyde, 2-methoxy-4 of a condensate of p-noazinophenylamine and formaldehyde
-Hydroxy-5benzoylbenzene sulfonate, p
-Condensates of noazinophenylamine and formaldehyde, such as tetrafluoroborates and hexafluorophosphates.

The present invention can also be preferably applied to a negative type 28 plate 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 such resins include shellac, derivatives of polyvinyl alcohol, copolymers having an alcoholic hydroxyl group in the side chain described in JP-A-50-118802, and copolymers having an alcoholic hydroxyl group in the side chain described in JP-A-55-155355. A copolymer having a 7enolic hydroxyl group in a side chain as shown in a is exemplified.

These resins include copolymers containing at least 50% by weight of structural units represented by the following general formula: R (C1,-C) Coo (CIlzCIIQ) nil (wherein, R
9 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom,
It represents a methyl group, an ethyl group or a chloromethyl group, and n is an integer of 1 to 10. ) and 1 to 80 mol% of a monomer unit having an aromatic hydroxyl group, and 5 to ° of an acrylic ester and/or methacrylic ester monomer unit.
Polymer compounds having an acid value of 90 mol% and an acid value of 10 to 200 are included.

Additions such as dyes, plasticizers, components imparting printout performance, etc. may be added to the photosensitive layer of the negative 23 plate to which the processing method of the present invention is applied.

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 7g/n+'.

There is no particular need to change the image exposure of the negative 23rd plate processed by the processing method of the present invention, and a conventional method may be used.

As the developer used in the present invention, an aqueous alkaline developer is preferable. Among the aqueous alkaline developers, for the negative type 23 plate in which a diazo compound or the like is used as a photosensitive substance, an alkaline agent, an organic solvent, an anionic surfactant, etc. Agents, sulfites, etc. impregnated with water as a solvent are 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.

Among these alkaline agents, the use of organic alkaline agents such as mono-, di-, or triethanolamine for negative 23 plates improves development performance and improves surface activity used in post-development processing. This is preferable from the viewpoint of suppressing a decrease in the processing ability of an aqueous solution containing a surfactant (hereinafter simply referred to as a surfactant solution).

Ethylene glycol monophenyl ether, benzyl alcohol, n-propyl alcohol, etc. are useful as organic solvents.

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.

Furthermore, adding a surfactant, especially an anionic surfactant, to the developer used in the method of the present invention improves the performance of the developer, but also reduces the processing ability of the surfactant used in the subsequent processing. Good for holding down.

As anionic surfactants, higher alcohols (C,
~C0) 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-81J
(trade name, manufactured by Shell Chemical), sodium alkyl sulfate, etc.], fatty alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate, etc.), alkylaryl sulfonates (e.g., dodecylbenzenesulfonic acid) sodium salts of isopropylnaphthalene sulfonic acid, sodium salts of sinaphthalene disulfonic acid, sodium salts of metanitrobenzenesulfonic acid, etc.), sulfonate salts of alkylamides (e.g., C+ t11j3CONCIIzC1lzS)
OJa, etc.), and sulfonic acid salts of dibasic C11° fatty acid esters (eg, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.). Among these, sulfonate salts are particularly preferably used.

Further, a sulfite salt may be added to the developer for the negative PS plate.

Sulfite has the function of dissolving water-insoluble diazo resin in an aqueous solution, and in particular, in the development of a 25 plate consisting of a photosensitive layer combined with a hydrophobic rJf resin, the printing plate is free of stains even after a long period of time has passed since its manufacture. can be made. α is preferable.

Examples of sulfites include alkali metal salts such as sodium, potassium, and lithium, and alkaline earth metal salts such as magnesium.

Furthermore, a chelating agent can be added to the developer for negative PS plates. A chelating agent is preferable because it has the effect of improving the performance of the developer and suppressing a decrease in the processing ability of the surfactant solution. As the chelating agent, for example, EDTA described in JP-A-58-190952,
Examples include NTA.

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 0.5 to 20 weight percent, preferably 0.5 to 20 weight percent, is used, and the pH is usually in the range of 9 to 13.

Further, as the alkali agent, an alkali metal silicate is preferable, and it is further preferable that 20% or more of the alkali metal silicate is potassium silicate.

The following additives can be added to such a developer in order to further improve the developing performance. For example, JP-A-58
-N aCQ, K CQKBr described in Publication No. 75152
Neutral salts such as E described in JP-A-58-190952
Chelating agents such as DTA and NTA, JP-A-59-121
[CO (old + 3) + 1) C (1) described in Publication No. 336
8. Complexes such as CoC (l t・6 II, O, etc., sodium alkylnaphthalene sulfonate described in JP-A-5O-5H24, 7-ion or amphoteric surfactant obtained from N-tetradecyl-N, N-dihydroxyethyl betaine) nonionic surfactants such as tetramethyldecynediol described in U.S. Pat. No. 4,374,920;
Cationic polymers such as the quaternized methyl chloride of p-methylaminomethylpolystyrene described in JP-A No. 95946, vinylbenol) I7 copolymers of methylammonium chloride and sodium acrylate described in JP-A-56-142528, etc. Ampholytic polymer electrolytes, reducing inorganic salts such as sodium sulfite described in JP-A No. 57-192952, non-fi IJ tium compounds such as lithium chloride described in JP-A-58-59444, JP-A-50-1983
Available fi such as lithium benzoate described in 34442 publication
17 tium compound, organometallic surfactant containing Si, Ti, etc. described in JP-A-59-75255, JP-A-59-75255
Examples thereof include organic boromine compounds described in Japanese Patent No. 9-84241, quaternary ammonium salts such as tetraalkylammonium oxide described in European Patent No. 1 Oioto, and organic solvents such as benzyl alcohol ethylene glycol monophenyl ether.

Among these additives, chelating agents, surfactants, and the like are preferable because they can prevent a decrease in the processing ability of an aqueous surfactant solution, similar to the additives for the developer for negative-tone PS plates described above.

Various conventionally known methods can be used to develop the image-exposed 25th 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 25th plate, a method of wiping the photosensitive layer of the PS plate with a sponge moistened with the developer, and a method of wiping the photosensitive layer of the PS plate Examples include a method of applying a developer to the surface using a roller.

Further, after the developer has been applied to the photosensitive layer of the 25th plate in this manner, the surface of the photosensitive layer can be lightly rubbed with a brush or the like.

The developing conditions may be appropriately determined depending on the above-mentioned developing method.

As for how to use the developer, the above-mentioned negative developer and positive developer are circulated and reused through their respective paths in the automatic developing machine.At this time, the development processing tank for the 25th plate is used for the negative PS. A common development tank is used for both the plate and the positive PS plate. Specifically, the developer for negatives and the developer for positives are stored in dedicated developer storage tanks, and when the PS plate to be developed is a negative 28 plate, the developer for negatives is stored in a common development tank. In the case of a positive PS plate, a common developing tank is supplied with a developer solution for heavy printing. A flow path switching valve may be provided in the recovery path of the used developer so that each developer flows back to its original storage tank. An example of such a treatment step is the method described in Publication No. 151401/1983.

In the present invention, it is necessary to identify the type of PS plate in order to switch 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: a manual method and an automatic method.

Examples of the artificial method include a method in which a person identifies and operates a button.

Automatic methods include, for example, optically measuring and identifying the concentration of the photosensitive layer, or measuring the spectral absorption of the photosensitive layer, or electrically measuring the impedance of the photosensitive layer. Alternatively, there may be a method of reading a signal stored in a memory element such as a magnetic card, or a method of reading a signal stored in a bar code. Furthermore, the developer replenisher may be replenished in response to exhaustion of the developer due to development processing of these PS plates or absorption of carbon dioxide gas 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 obtained by developing in this way is preferably squeezed so that the amount of developer on the plate surface is reduced, and further, the surface of the lithographic printing plate that remains after being squeezed. The amount of second developer is 10mQ/+
It is preferably less than n''.

The remaining amount of the developer is more preferably 5 m(!/n+'' or less, most preferably 3 m12/m' or less).

In this way, the smaller the remaining amount of the developer is, the more preferable it is because the reduction in processing ability of the aqueous surfactant solution can be suppressed.

Examples of methods for squeezing the surface of a lithographic printing plate include passing the lithographic printing plate between a pair of elastic rollers whose surfaces are coated with an elastic member such as rubber, and removing the developer on the plate surface by the nip pressure; Examples include a method in which an elastic plastic material with a smooth surface is placed along the conveyance path of the lithographic printing plate and brought into sliding contact with the plate surface, thereby scraping off the developer from the plate surface.

The lithographic printing plate obtained in this way is then used in the world.

It is treated with an aqueous solution containing a surfactant (hereinafter simply referred to as a surfactant solution). The above-mentioned surfactants that can be used in the present invention include various types. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystylphenyl ether, polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial esters,
Sorbitan fatty acid partial esters, pentaerythritol 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, polyoxyethylated castor oil,
Polyoxyethylene glycerin fatty acid partial esters,
Nonionic surfactants such as fatty acid jetanolamides, N,N-bis-2-hydroxyalkylamines, polyoxyethylenealkylamines, triethanolamine fatty acid esters, trialkylamine oxides,
Fatty acid salts, avicenoates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinate ester salts, linear alkylbenzenesulfonates, branched alkylbenzenesulfonates,
Alkylnaphthalene sulfonates, alkylphenoxypolyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N
-Methyl-N-oleyl taurine sodium salts, N-alkylsulfosuccinic acid monoamide disodium salts, petroleum sulfonates, sulfated castor oil, sulfated tallow oil, sulfate ester salts of fatty acid alkyl esters, alkyl sulfate ester salts, polyoxy Ethylene alkyl ether sulfate ester salts, fatty acid monoglyceride sulfate ester salts, polyoxyethylene alkyl phenyl ether sulfate ester salts, polyoxyethylene styryl furanyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkyl ether sulfate ester salts, Anionic products such as oxyethylene alkyl phenyl ether phosphate ester salts, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, naphthalene sulfonate formalin condensates, etc. Surfactants, alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, cationic surfactants such as polyethylene polyamine derivatives, carboxybetaines,
Examples include amphoteric surfactants such as aminocarboxylic acids, sulfobetaines, aminosulfate esters, and imidacillins.

Among the surfactants listed above, polyoxyethylene includes polyoxymethylene, polyoxypropylene,
This can also be read as polyoxyalkylene such as polyoxybutylene, and these surfactants are also included in the following description.

Among these, polyoxyethylene alkyl ethers,
Polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial 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 fat [2 esters, polyoxyethylated castor oil, dialkyl sulfosuccinates, alkylbenzene sulfonates, alkylnaphthalene sulfones] Acid salts, alkyl sulfate ester salts, fatty acid salts, alkyl phosphate ester salts, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl amine salts, alkyl amine salts, and quaternary ammonium salts may affect the image area of the lithographic printing plate. Preferred are polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyrylphenyl ethers, polyoxyethylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, and Particularly preferred are oxyethylene sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol monofatty acid esters, polyethylene glycol fatty acid esters, dialkyl sulfosuccinate ester salts, alkyl sulfate ester salts, and alkylbenzene sulfonate salts.

The most preferred are alkyl and benzene sulfonate salts and dialkyl sulfosuccinate 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. I)H of the aqueous solution containing the surfactant in the present invention is preferably 1 to 12.

In addition, if the developer of the 28th plate is alkaline, the surfactant solution has the ability to neutralize the developer remaining on the developed PS plate, or the ability to lower the pH of the remaining developer. It is preferable to have it provided.

Such ability can be imparted by further containing an acid and/or a buffer in the surfactant solution.

Preferred compounds that can be used in such acids and buffers include inorganic acids such as molybdic acid, boric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, acetic acid, oxalic acid, tartaric acid, benzoic acid, succinic acid, citric acid, malic acid. , lactic acid, p-toluenesulfonic acid, and other water-soluble organic acids, and salts thereof.

More preferred salts are water-soluble alkali metal salts and ammonium salts, specifically, for example ammonium acetate,
Sodium acetate, potassium acetate, sodium molybdate, potassium molybdate, sodium borate, ammonium borate, lithium nitrate, sodium nitrate, potassium nitrate, monobasic sodium phosphate, dibasic sodium phosphate, tribasic sodium phosphate, dihydrium phosphate, Examples include dibasic potassium phosphate, tribasic potassium phosphate, tribasic ammonium phosphate, and sodium polyphosphate.

These acids and water-soluble salts can be used alone or in combination.

A more preferable pH of the surfactant solution is 2-8.

The most preferable pH is 2.5 to 6.5, in which case the desensitization performance of the non-image areas of the lithographic printing plate becomes higher.

The amounts of the acid and salt added to the solution are not particularly limited, but the total amount of the acid and salt is preferably about 10% by weight or less based on the total weight of the aqueous solution. More preferably 0.0
It is used in a range of 1 to 6% by weight.

The surfactant solution in the present invention further includes sorbic acid, p.
- Preservatives and preservatives such as ethyl oxybenzoate, antioxidants such as propyl gallate, 2,6-di[-butyl-4-ethylphenol, 2,6-di[-butyl-4-methylphenol] can be contained. By adding a small amount of these preservatives, antifungal agents, and antioxidants, it is possible to prevent deterioration in quality due to storage of the aqueous solution, but the preferred addition amount is O.
~5% by weight.

It is preferable that the surfactant solution in the present invention contains a lipophilic substance, so that the image area of the lithographic printing plate exhibits higher liposensitivity, and development ink is easily deposited. Not only this, but when the plate surface protectant treatment is performed after the treatment with the aqueous solution, the decrease in oil sensitivity of the image area can be strongly suppressed. 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, palmitic 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 weight.
from about 10% by weight, more preferably from 0.05 to 5% by weight
is within the range of

In the method of processing with a surfactant solution of the present invention, it is necessary to supply the surfactant solution to the lithographic printing plate obtained by the development treatment without passing through a water washing step.

Examples of methods for supplying the surfactant solution onto the lithographic printing plate include spraying it from a nozzle or shower pipe,
Examples include a method of wiping the surface of the lithographic printing plate with a sponge wetted with a surfactant solution, and a method of applying a surfactant solution to the surface of the lithographic printing plate using a roller or the like.

Further, as the method for supplying the surfactant solution, only one method may be used, or two or more methods may be used in combination.

In this way, after or while supplying the surfactant solution to the surface of the lithographic printing plate, the surface of the lithographic printing plate can be lightly rubbed with a rubbing member such as a brush. Further, these rubbing members and the surfactant solution supplying means may be integrated.

In addition, the replenisher can be replenished in response to a decrease in the amount of the surfactant solution due to fatigue and/or carry-out.

Furthermore, the lithographic printing plate obtained by the processing method of the present invention can be subjected to various steps such as development ink filling, correction such as addition or erasure, gumming, etc.
Furthermore, both of these steps can be performed without any problems.

The present invention will be explained in more detail below with reference to Examples.

[Example] 3 parts by weight of an ester compound of naphthoquinone 1,2-diazido-5-sulfonyl chloride and resorcinol-benzaldehyde resin (described in Example 1 of JP-A-56-1044), cresol novolak A photosensitive solution was prepared by dissolving 9 parts by weight of the resin and 0.12 parts by weight of Victoria Buer Blue BOH (dye manufactured by Hodogaya Kagaku Kogyo Co., Ltd.) in 100 parts by weight of methyl cellosolve.

A grained aluminum plate with a thickness of 0.3 mm was anodized in sulfuric acid to form an oxide film of about 2.5 g/m', which was thoroughly washed and dried. The above photosensitive solution was applied on it and dried. Positive type 28 with a photosensitive layer of 2.5g/mm
Got the edition.

In addition, a copolymer of parahydroxyphuninylmethacrylamide, acrylonitrile, ethyl acrylate, and methacrylic acid (molar ratio is 8.5: 24 in the above order)
: 60.5 : 7) 5.0 parts by weight Hexafluorophosphate of a condensate of P-diazodiphenylamine and paraformaldehyde 0.5 parts by weight Victoria Vinier Blue BOH (manufactured by Hodogaya Chemical Co., Ltd. 0.1 parts by weight) A photosensitive solution was prepared by dissolving the following in 100 parts by weight of methyl cellosolve.

Next, a grained aluminum plate with a thickness of 0.24 mm was anodized in sulfuric acid to remove an oxide film of about 2 g/m', thoroughly washed, then immersed in an aqueous sodium silicate solution, thoroughly washed with water, and then dried. A photosensitive solution having the above composition was coated on the support obtained by this process and dried to obtain a negative type 18 plate having a photosensitive layer of about 1.8 g/m''.

The positive PS plate and negative type 28 obtained in this way
A large number of plates were prepared by cutting them into sizes of 1003 x 800 mm.

The positive PS plate was then exposed through the transparency for 60 seconds from a distance of 80cI11 using a 2KW metal halide lamp. In addition, the negative type 28 plate was exposed for 30 seconds under the same conditions through a transparent negative.

On the other hand, a potassium silicate aqueous solution (Sio, content 26% by weight, KIO
Using a potassium hydroxide aqueous solution (48 wt% aqueous solution) and pure water, the molar ratio of Stow and KtO ((stow)/(KtO)) was 1.
In 78, a developer with a molar concentration of O of 3.90 mol/f2 and a molar ratio of silicic acid and potassium (5iO=/K
mO) is 0.88, and the molar concentration of K and O is 7.78 mol/
A developer replenisher of Q was prepared.

Furthermore, a developer having the following composition was prepared as a developer for a negative PS plate.

"Ethylene glycol monophenyl ether and water"
Further, an automatic developing machine shown in FIG. 1 was prepared.

In Fig. 1, l is a developing tank, 2 is a transport roller, 3 is a squeezing roller, 4 is a receiver roller, 5 is a brush roller, 6 is a positive developer storage tank, and 6' is a positive developer replenisher storage tank. Tank, 7 is positive shower pipe, 8 is positive pump, 8'
9 is a developer replenisher pump for positives, 9 is a developer storage tank for negatives, 10 is a shower pipe for negatives, 11 is a pump for negatives,
12 is a flow path switching valve. 13 is a surfactant solution treatment tank, 14 is a surfactant solution supply pump, 15 is a surfactant storage tank, and 16 is a shower pipe for the surfactant solution.

Reference numeral 17 is a light reflection sensor that identifies the type of plate 28 to be processed, and 18 is a control device that operates the pump and controls the flow path switching valve based on the type information.

The negative developing solution and the positive developing solution were charged into the corresponding developing solution storage tanks of the automatic processor in an amount of 40a each, and the developer replenisher was charged into the developer replenishing solution storage tank in an amount of 3012. Further, 2 ON of a treatment liquid having the following composition was charged into the storage tank 15.

"Sodium lauryl sulfate 0.2 parts by weight water 100 parts by weight The pH of this processing solution was 5.7. The temperature of the developer was kept at 25°C for both negative and positive applications, and the developing time was 40 seconds. In addition, the developer replenisher for positives was replenished at 21mFF every time one plate was developed, and was replenished at a rate of 35mQ per hour, regardless of the development process. The selection of the positive developer is performed by the control device 18 based on the identification signal from the light reflection sensor 17.

Further, the control device 18 controls the operation of the developer supply pump 8, 11, the processing solution supply pump 14, and the developer replenisher pump 8', and controls the switching of the switching valve 12.

In this way, the negative-type PS plates and 28 positive-type plates of the exposure process were processed alternately, 35 plates each for a total of 70 plates, and 69
The 70th processed negative planographic printing plate and the 70th processed positive planographic printing plate were gummed with a gum solution having the following composition.

``Dextrin: 200 parts by weight Water: 784 parts by weight When the resulting lithographic printing plates were printed using a printing machine, the ink receptivity in the image area was good, and the ink was completely transferred to the paper within 19 sheets of each plate. .

Furthermore, the desensitizing effect of the non-image area was not impaired, and no scumming occurred at all, making it possible to obtain excellent printed matter.

Furthermore, for the 68th processed positive planographic printing plate,
When developing ink was applied in a conventional manner using a commercially available developing ink composition without gumming, the process was easily carried out without any problems.

As a comparison with the above-mentioned plate-making method, a conventional method was used, in which instead of the desensitized portion of the above-mentioned example, the desensitized portion was treated in the same manner as the conventional method of washing under running water, and then the desensitized treatment liquid was applied. . When the negative lithographic printing plate obtained in the 69th process and the positive lithographic printing plate processed in the 70th process were printed on a printing press, the ink was completely transferred to the paper within 27 pages for both plates. It was done. This method also consumed a total of too much wash water.

In this way, 28 negative plates and 28 positive plates were treated in common, and treated with an aqueous solution containing a surfactant without washing with water.
Even after the subsequent desensitization treatment, the obtained lithographic printing plate has no inferiority in printing ink receptivity compared to the normal treatment with water washing, and in fact it is superior. There was no damage to it. Furthermore, it was possible to significantly save washing water. It was also possible to apply ink even more easily.

〔Effect of the invention〕

According to the present invention, even when 28 plates of negative type and positive type are mixed and processed without washing with water using the same automatic developing machine, the non-image areas are highly insensitive and the ink build-up is high.
It has become possible to stably produce high-quality lithographic printing plates that can be easily modified.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an automatic developing machine used in the above embodiment.

Claims (1)

[Claims] Using an automatic processor, negative photosensitive lithographic printing plates and/or
Alternatively, positive-working photosensitive lithographic printing plates are automatically transported and stored in separate developer storage tanks in the same development zone of the automatic processor, depending on the type of photosensitive lithographic printing plate being processed. A developing solution for negative or positive photosensitive planographic printing plates that is used in circulation is supplied to the photosensitive planographic printing plate surface for development processing, and then an aqueous solution containing a surfactant is supplied to the plate surface for processing. A method for processing a photosensitive lithographic printing plate, characterized by: