JPH02256053A - Method for developing photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To improve the stability of finish of each of negative and positive type photosensitive planographic printing plates developed with a developing soln. common to the plates by forming a replenisher for development with specified two kinds of solns. and replenishing the solns. in different ratios when the plates are developed. CONSTITUTION:A replenisher for development is formed with an aq. soln. (A) contg. alkali silicate and a soln. (B) contg. at least one kind of nonionic or cationic surfactant. When negative and positive type PS plates are developed with a developing soln. common to the plates, the solns. A, B are replenished in different ratios. The stability of finish of each of the developed plates is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for developing a photosensitive lithographic printing plate (hereinafter referred to as "23rd plate"). The present invention relates to a method for replenishing a developer replenisher in a method for commonly developing a negative 28 plate and a positive PS plate with a common negative/positive developer which is repeatedly used by replenishing the solution.

[Conventional technology]

A developer composition that commonly develops a negative 28 plate (using a diazo compound as a photosensitive component) and a positive PS plate (using a quinonediazide compound as a photosensitive component) with one automatic developing machine. as JP-A-60-13074
No. 1, No. 62-25761, No. 62-168160, No. 62-175757, etc. disclose developer compositions that are suitable for common negative and positive development, and also disclose developer compositions that are compatible with repeated use of alkaline developers. As a replenishment technique for the development processing method that develops both negative and positive, Japanese Patent Application Laid-Open No. 1986-
No. 73271 discloses a technique for stabilizing the developability during repeated use by using a replenisher containing a silicate having a higher alkaline strength than the developer being replenished.

In addition, the same document describes that the developer replenisher is divided into two parts, one is an alkaline solution containing silicate, the other is an anionic surfactant, sulfite, and an organic solvent, and negative type 2
It is also described that the ratio of the amounts of the two liquids to be replenished should be changed between the 8th edition and the positive PS edition. However, even if the developing ability is kept constant through replenishment using such techniques, there is a drawback that quality such as gradation gradually deteriorates.

[Problem that the invention seeks to solve]

Therefore, an object of the present invention is to improve the stability of the developed finish in a PS plate development method in which an automatic developing machine is used and a common negative/positive developer is used repeatedly by replenishing the replenisher. An object of the present invention is to provide a development processing method.

Means for Solving Problems c] An object of the present invention is to develop a negative-type 28th plate and a positive-type 25th plate using an automatic developing machine and a negative/positive common developer that can be used repeatedly by replenishing the developer replenisher. In the development processing method for developing, the developer replenisher contains at least the following (A) and (
B), and the negative type 28th edition and the positive type 25th edition are the same (A).
This is achieved by a PS plate development processing method that replenishes by changing the ratio of replenishment amounts of (B) and (B).

(A) Aqueous solution containing alkali silicate.

(B) A solution containing at least one selected from nonionic surfactants and cationic surfactants.

The present invention will be explained in detail below.

The alkali silicate contained in the aqueous solution (A) (hereinafter referred to as "solution A") constituting the developer replenisher in the present invention is, for example, potassium silicate, sodium silicate, or the like.

Solution (A) contains, in addition to alkali silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate,
Inorganic alkaline agents such as potassium diphosphate, ammonium triphosphate, ammonium diphosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc., di- or triethanolamine, and water. It can contain organic alkaline agents such as tetraalkyl oxides, organic sodium silicate, and the like.

Various nonionic surfactants can be used in the solution (B) (hereinafter referred to as "solution B").

Nonionic surfactants can be broadly classified into polyethylene glycol type and polyhydric alcohol type, and both can be used in the present invention, but polyethylene glycol type nonionic surfactants are preferred from the viewpoint of the magnitude of the effect. , among which ethyleneoxy group (-CH, CH, O-)
3 or more, and HLB value (HLB is Hydrop
hile-Abbreviation of Lipophile Balance)
is more preferably a nonionic surfactant of 5 or more (more preferably 8 to 20).

Moreover, among nonionic surfactants, those having both an ethyleneoxy group and a propyleneoxy group are particularly preferable, and among these, those having an HLB value of 8 or more are more preferable.

Preferred examples of the nonionic surfactant used in the developer of the present invention are as follows - Formulas (1) to [8] CI ) R
O(CHtCH20)nf((6) HO(C2Ha
O)a-(CJaO)b (C2H,0)cH(7)
H(OCJn))' (OCJs)X in/(Cs
HsO))E (czo*o)y.

H(OCzH*)Y (OCJn6)X/\(C3■
ao)x (C2H,0)yH(8) HO-CC
In formulas H, CH, 0)nH (1) to [8], R represents a hydrogen atom or a monovalent organic group. The organic group includes, for example, a linear or branched substituent having 1 to 30 carbon atoms (
For example, an alkyl group that may have an aryl group (such as phenyl), an alkylcarbonyl group whose alkyl moiety is the above-mentioned alkyl group, or an alkyl group that has a substituent (such as a hydroxyl group, the above-mentioned alkyl group, etc.). Examples include a phenyl group and the like. 8% bsc, m, n, x and y each represent an integer from 1 to 40.

Next, specific examples of nonionic surfactants used in the present invention will be shown.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene Polyoxypropylene behenyl ether, polyoxyethylene nonylphenyl ether, holoxyethylene octylphenyl ether, polyoxyethylene stearylamine, polyoxyethylene oleylamine,
Polyoxyethylene stearamide, polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, holoxyethylene monostearate, polyoxyethylene Glyceryl monooleate, polyoxyethylene glycer monostearate, polyoxyethylene propylene glycol monostearate, oxyethylene oxypropylene block polymer, distyrenated phenol polyethylene oxide adduct, tribenzylphenol polyethylene oxide adduct, octylphenol polyoxyethylene polyoxy propylene adduct,
Glycerol monostearate, sorbitan monolaurate, polyoxyethylene sorbitan monolaurate, etc.

The weight average molecular weight of the nonionic surfactant used in the present invention is preferably in the range of 300 to 10,000, and preferably in the range of 500 to 500.
A range of 0 is particularly preferred. One nonionic surfactant may be contained alone, or two or more types may be used in combination.

Various cationic surfactants can be used for solution B. Cationic surfactants are broadly classified into amine type and quaternary ammonium salt, and any of these can be used in the present invention.

Examples of amine types include polyoxyethylene alkylamine, N-alkylpropylene amine, N-alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, long chain amine oxide, alkylimidacilline, ■-hydroxy Ethyl-2-alkylimidacyline, ■-acetylaminoethyl-2-alkylimidacyline, 2-alkyl-4
-Methyl 4-hydroxymethyloxazoline and the like.

Examples of quaternary ammonium salts include long-chain primary amine salts, alkyltrimethylammonium salts, dialkyldimethylethylammonium salts, alkyldimethylammonium salts, alkyldimethylbenzylammonium salts, alkylpyridinium salts, and alkylquinolinium salts. , alkylisoquinolinium salt, alkylpyridinium sulfate, stearamidemethylpyridinium salt, acylaminoethyldiethylamine salt, acylaminoethylmethyldiethylammonium salt, alkylamidopropyldimethylbenzylammonium salt, fatty acid polyethylene polyamide, acylaminoethylpyridinium salt , acylcolaminoformylmethylpyridinium salt, stearoxymethylpyridinium salt, fatty acid triethanolamine, fatty acid triethanolamine formate, trioxyethylene fatty acid triethanolamine, fatty acid dibutylaminoethanol, cetyloxymethylpyridinium salt, p
-inoctylphenoxyethoxyethyldimethylbenzylammonium salt and the like. (In the above compound examples, "alkyl" refers to a straight-chain or partially substituted alkyl having 6 to 20 carbon atoms, and specifically, straight-chain alkyl such as hexyl, octyl, cetyl, stearyl, etc.) Among these, water-soluble quaternary ammonium salt type cationic surfactants are particularly effective; among them, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, and ethylene oxide
ta ammonium salt and the like are preferred. Further, a polymer having a cationic component as a repeating unit is also a cationic surfactant in a broad sense, and the cationic surfactant of the present invention has a golden color. In particular, a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic hexamer can be suitably used.

The weight average molecular weight of the polymer is in the range of 300 to 50,000, particularly preferably in the range of 500 to 5,000.

These cationic surfactants can be used alone,
Two or more types may be used in combination.

Preferably, solution B contains an organic solvent.

The organic solvent preferably has a solubility in water of 10% by weight or less at 20°C.

Examples of organic solvents having a solubility in water of 10% by weight or less include carboxylic acid esters such as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, and butyl levulinate; Ketones such as butyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols such as ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, and methyl amyl alcohol; xylene Alkyl-substituted aromatic hydrocarbons such as; halogenated hydrocarbons such as methylene dichloride, ethylene dichloride, and monochlorobenzene. One or more of these organic solvents may be used.

The organic solvent is an excellent additive for improving the developability of both negative and positive PS printing plates, but at the same time it degrades the film in the image area for positive type 23 plates. It also has drawbacks. Positive type 23 plate has negative type 2 when exposed.
Since it does not undergo a crosslinking reaction like the third printing plate, the film deteriorates significantly when development is excessive, and the degree of deterioration becomes even greater in the presence of organic solvents. As mentioned above, in order to prevent the deterioration of the film during development of the positive type 23rd plate and to develop the negative type 23rd plate well, it is necessary to include a nonionic and/or cationic surfactant in the developer. effective.

In the present invention, solution A may contain components contained in solution B, and solution B may contain components contained in solution A within a range that does not impede the effects of the present invention. just.

However, the total concentration of nonionic surfactant and cationic surfactant and the concentration of organic solvent in solution A must be lower than in solution B, and the concentration of alkali silicate in solution B must be lower than that in solution A. It is necessary that the

The concentration of each component of solution A and solution B may be any concentration that can maintain the preferred component concentration, pH, and other conditions of the developing mother liquor by replenishment.

In the present invention, the concentration of alkali silicate in the developing mother liquor is preferably 0.05 to 20% by weight, more preferably 0.05 to 20% by weight.
The pH of the developing mother liquor is preferably 12 or more, particularly preferably 12.5 to 13.5. Solution A
The appropriate concentration of alkali silicate therein is in the range of 0.1-10 mol/Q. Although it is preferable that the solvent of solution A consists of only water, it may contain an organic solvent to the extent that the effects of the present invention are not impaired.

The concentration of nonionic surfactant and cationic surfactant in the development mother liquor is 0.001 to 10% by weight in total concentration of both.
, particularly preferably in the range of 0.01-1% by weight.

The total concentration of the nonionic surfactant and cationic surfactant in solution B is suitably in the range of 0.1 to 10% by weight.

The concentration of the organic solvent in the development mother liquor is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight. The concentration of the organic solvent in solution B is suitably in the range of 1 to 30% by weight.

The developer mother solution and developer replenisher (hereinafter collectively referred to as "developer") of the present invention preferably contain an organic carboxylic acid. The organic carboxylic acid is preferably an aliphatic carboxylic acid having 6 to 20 carbon atoms, or an aromatic carboxylic acid in which a benzene ring or a naphthalene ring is substituted with a carboxyl group.

The aliphatic carboxylic acid is preferably an alkanoic acid having 6 to 20 carbon atoms, and specific examples include caproic acid, enantylic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, mystylic acid, palmitic acid, and stearic acid. etc., and particularly preferred are alkanoic acids having 6 to 12 carbon atoms. Also, fatty acids with double bonds in their carbon chains,
It may also have a branched carbon chain. In order to improve water solubility, the aliphatic carboxylic acid is preferably used as a sodium or potassium salt or an ammonium salt.

Specific compounds of aromatic carboxylic acids include benzoic acid, 0-chlorobenzoic acid, p-chlorobenzoic acid, 0-hydroxybenzoic acid, p-hydroxybenzoic acid, p-ter
t-butylbenzoic acid, 0-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2.5-dihydroxybenzoic acid, 2.3-dihydroxybenzoic acid,
2.3-dihydroxybenzoic acid, 3゜5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-7toic acid, 2-hydroxy-
Among them, benzoic acids are particularly effective.

The above aromatic carboxylic acid is preferably used as a sodium or potassium salt or an ammonium salt in order to improve water solubility.

The concentration of organic carboxylic acid in the development mother liquor is preferably 0.
1-10% by weight, more preferably 0.5-4% by weight.

The developer of the present invention preferably contains a water-soluble or alkali-soluble organic and inorganic reducing agent.

Examples of organic reducing agents include phenolic compounds such as hydroquinone, methol, and methoxyquinone, and amine compounds such as phenylenediamine and phenylhydrazine. Examples of inorganic reducing agents include sodium sulfite, potassium sulfite, ammonium sulfite, and hydrogen sulfite. Sulfites such as sodium and potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite,
Examples include phosphates such as potassium hydrogen phosphite, sodium dihydrogen phosphite, and potassium hydrogen sulfite, hydrazine, sodium thiosulfate, and sodium dithionite. The reducing agent is preferably contained in the developing mother liquor in an amount of 0.1 to 10% by weight.

Further, the following additives can be added to the developer used in the present invention in order to further improve the development performance. For example, NaCα, KCQ described in JP-A-58-75152
Neutral agents such as Br, etc., chelating agents such as EDTA and NTA described in JP-A-59-190952, JP-A-59-1909-
Complexes such as (Co(NHs)) Ic et al. described in JP-A No. 121336, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56/142528, JP-A-Sho Inorganic lithium compounds such as lithium chloride described in Japanese Patent Publication No. 58-59444, organic lithium compounds such as lithium benzoate described in Japanese Patent Publication No. 50-34442, JP-A-59
Examples include organometallic surfactants containing Si, Ti, etc. described in Japanese Patent Application Laid-Open No. 59-84241.

In a preferred embodiment of the present invention, the developer replenisher is added to solution A.
and solution B and dilution water as necessary, positive type 2
One example is a mode in which the ratio of the replenishment amount of solution A and solution B is changed depending on the throughput of the third plate and the negative PS plate and the amount of air oxidation. In the present invention, the developer replenisher may be used as a concentrated solution and diluted with water.

A preferred embodiment of the present invention is an embodiment in which the developer contains at least one of a nonionic surfactant and a cationic surfactant and an organic solvent.

The photosensitive composition of the PS plate to which the method of the present invention is applied contains a photosensitive substance as an essential component, and the physical and chemical properties of the photosensitive substance change upon exposure or subsequent development treatment. , for example, those that have a difference in solubility in a developing solution due to exposure, those that have a difference in intermolecular adhesive strength before and after exposure, those that have a difference in affinity for water and oil due to exposure or subsequent development treatment, and An image area can be formed by electrophotography, and JP-A-55-1
A multi-layer structure as described in No. 66645 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-〇- that decomposes with acids. Examples include compounds having a C group. Typical positive-type compounds that become alkali-soluble upon exposure include 0-quinonediazide compounds, acid-decomposable ether compounds, and ester compounds.

Aromatic diazonium salts are examples of negative-type compounds whose solubility decreases upon exposure 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, No. 4
No. 9-17481, U.S. Pat. No. 2,797,213, U.S. Pat. No. 3,046.120, U.S. Pat.
, 454.400, 3,544゜323, 3,
No. 573.917, No. 3,674.495, No. 3,7
No. 85゜825, British Patent No. 1,227,602, No. 1
, 251.345, 1,267.005, 1.
329.888, German Patent No. 1,330,932, and German Patent No. 854,890.
The present invention can be preferably applied at least to PS plates using these compounds alone or in combination as photosensitive components.

These photosensitive components include 0-quinonediazide sulfonic acid ester or 0-quinonediazidecarboxylic acid ester of an aromatic hydroxy compound and 0-quinonediazide sulfonic acid amide or 0-quinonediazidecarboxylic acid amide of an aromatic amine compound; These include those in which the 0-quinonediazide 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.

Alkali-soluble resins include novolak-type phenolic resins, and specifically include phenol formaldehyde resins, cresol formaldehyde resins, phenol-cresol mixed formaldehyde resins, cresol xylenol mixed formaldehyde resins, and the like. Furthermore, as described in JP-A-50-125806, in addition to the above-mentioned phenol resin, phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms such as t-butylphenol formaldehyde resin and formaldehyde are used. It is also possible to use a condensate of the same. 0
-The photosensitive layer containing a quinonediazide compound as a photosensitive component includes:
If necessary, additives such as dyes, plasticizers, and components imparting printout performance can be added.

The amount per unit area of the photosensitive layer containing the 0-quinonediazide compound as a photosensitive component is preferably about 0.5 to 7 g/mfi.
The present invention can be applied to the range of

The image exposure of the positive photosensitive lithographic printing plate to which the method of the present invention is applied does not need to be particularly changed and may be carried out in accordance with a conventional method.

A typical photosensitive component of the negative photosensitive layer is a diazo compound, such as a diazo resin which is a condensate of diazonium salt and/or p-diazodiphenylamine and formaldehyde, as described in Japanese Patent Publication No. 7364/1983. p
- A diazo resin consisting of an organic solvent-soluble salt of a copolycondensate described in Japanese Patent Publication No. 49-48001, such as a 7-enol salt or a fluorocapric acid salt of diazodiphenylamine; a condensate of p-diazodiphenylamine and formaldehyde; Examples include 2-methoxy-4-human axy-5-benzoylbenzenesulfonate, tetrafluoroborate of a condensate of p-diazodiphenylamine and formaldehyde, and hexafluorophosphate. The present invention can be preferably applied at least to negative type 23 plates containing these as photosensitive components.

In addition to those in which these diazo compounds are used alone, the present invention can also be applied to those in which they are used in combination with various resins in order to improve the physical properties of the photosensitive layer. Examples of such resins include shellac, polyvinyl alcohol derivatives, 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. Examples include copolymers with phenolic hydroxyl groups in their side chains.

These resins include a copolymer containing at least 50% by weight of a structural unit represented by the following formula: R3 (CI(!-C) COO(CH2CHO)nH (where R is a hydrogen atom or a methyl group) , R5 represents a hydrogen atom, 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 monomer units having an aromatic hydroxyl group, and acrylic Included are polymer compounds having 5 to 90 mol% of acid ester and/or methacrylic ester monomer units and having an acid value of 10 to 200.

The photosensitive layer of the negative PS plate to which the 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/m''.

Supports used in the above PS include paper, plastic (e.g. polyethylene, polypropylene, polystyrene, etc.) laminated paper, aluminum (including aluminum alloys), metal plates such as zinc, copper, etc., cellulose diacetate, Examples include films of plastics such as cellulose triacetate, cellulose propionate, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, and polyvinyl acetal, paper laminated or vapor-deposited with the above metals, or steel plates plated with chrome. Among these, aluminum and aluminum-coated composite supports are particularly preferred.

Further, the surface of the aluminum material is preferably roughened for the purpose of increasing water retention and adhesion to the photosensitive layer.

Examples of the surface roughening method include generally known methods such as brush polishing, pole 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 may be mentioned, among which 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. Liquid is 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, and particularly preferred is a method of treatment in a bath containing sulfuric acid or phosphoric acid.

Further, if necessary, a sealing treatment and other surface treatments such as immersion in an aqueous potassium zirconate solution can be performed.

In addition to the development process according to the development method of the present invention, if necessary, after the development process, a development stop process (the stop process solution includes a disposable method or a recycle method), a desensitization process, etc. Each individual treatment step, a development stop treatment step followed by a desensitization treatment step, a treatment step combining a development treatment step and a degreasing treatment, or a combination of a development stop treatment step and a desensitization treatment step, for example, Kaisho 54-
The processing steps described in Japanese Patent No. 8001 may also be included.

In the present invention, the negative 23rd plate and the positive 28th plate are tested under conditions other than the developer composition (e.g. development temperature, development time, etc.).
It is optional, such as changing between negative type and positive type.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to specific examples, but the present invention is not limited thereto.

In addition, "potassium silicate aqueous solution" in the following examples
Both have a Sin content of 26% by weight and a K,0 content of 13% by weight.

Example 1 24ρ of the following developer [A] was used in an automatic developer Konica PSK9.
10 (manufactured by Konica Corp.) and the liquid temperature was maintained at 27°C.

Further, the setting was made so that the developing time was 20 seconds. Next, the following replenishers (A) and CB) were prepared.

Developer (A) β-anilinoethanol 3 MIk parts Propylene glycol betaoxynaphthoic acid p-tert-butylbenzoic acid Emulgen 147 (nonionic surfactant) (polyoxyethylene lauryl ether, Kako Co., Ltd.) Potassium sulfite Potassium silicate Aqueous potassium hydroxide water replenisher (A) Potassium silicate aqueous solution Potassium hydroxide water replenisher CB) β-anilinoethanol propylene glycol betaoxynaphthoic acid p-tert-butylbenzoic acid Emulgen 147 3 parts by weight 6 parts by weight 12 parts by weight 0.3 parts by weight 9 parts by weight 22 parts by weight 15 parts by weight 900 parts by weight Potassium sulfite 9 parts by weight Potassium silicate aqueous solution 20 parts by weight Potassium hydroxide 30 parts by weight Water
800 parts by weight In the automatic developing machine prepared in this way, the step tablet was used as an original and image-exposed. 1003mm 8800man negative PS version "SWN" (manufactured by Konica Corporation) and 10010O380
A total of 100 sheets of 0 mm positive type 25th plate "SMP-N" (manufactured by Konica Corp.) were continuously and randomly developed. During this time, replenishers (A) and CB) were added per unit area of the 28 treated plates at the ratios shown in the table below.

60 parts by weight 25 parts by weight 830 parts by weight 3 parts by weight 6 parts by weight 6 parts by weight 15 parts by weight There was almost no difference between the developed step tablet and the last developed step tablet.

Example 2 An experiment similar to Example 1 was conducted except that the following developer solution CB), replenisher (C), and [:D) were used, but the initial development and the final development were performed. There was almost no difference in Ste Nobu tablet.

Developer CB) Phenyl cellosolve 6 parts by weight Propylene glycol 3 parts by weight p-tert
-Butylbenzoic acid 15 parts by weight Esocard 18/25 (cationic surface 0.5 parts by weight activator,
Lion Acry Co., Ltd.) Sodium sulfite 7 parts by weight Potassium silicate aqueous solution 25 parts by weight Potassium hydroxide 15 parts by weight Water
900 parts by weight replenisher [C
] Potassium silicate aqueous solution Potassium hydroxide Emulgen 147 Water 60 parts by weight 25 parts by weight 0.05 parts by weight 830 parts by weight Replenisher CD) Phenyl cellosolve 6-fold Jig Propylene glycol 6 parts by weight p-ter
t-Butylbenzoic acid 18 parts by weight Esocard 18/25 4 parts by weight Sodium sulfite 10 parts by weight Potassium silicate aqueous solution 15 parts by weight Potassium hydroxide
30 parts by weight water
800 parts by weight Example 3 The same experiment as in Example 1 was conducted except that the following developer [C] and replenisher (E), CF) were used, but There was almost no difference in Ste Nobu tablet.

Developer CG) β-anilinoethanol 1 part by weight Propylene glycol 6 parts by weight p-te
rt-Butylbenzoic acid 12 parts by weight Emulgen 147 0.2 parts by weight Esocard 18/25 0.15 parts by weight Potassium sulfite aqueous potassium silicate solution Potassium hydroxide water replenisher (E) Potassium silicate aqueous solution Potassium hydroxide water replenisher CF) β-anilinoethanol propylene glycol p-tert-butylbenzoic acid Emulgen 147 Esocard 18/25 Potassium sulfite potassium silicate aqueous solution Potassium hydroxide water Comparative examples The following developer solution [D] and replenisher solution [G].

9 parts by weight 22 parts by weight 15 parts by weight 900 parts by weight 60 parts by weight 25 parts by weight 830 parts by weight 2 parts by weight 9 parts by weight 15 parts by weight 3 parts by weight 1 part by weight 12 parts by weight 20 parts by weight 15 parts by weight 900 parts by weight (H ) was used, but the same experiment as in Example 1 was conducted, but a difference was observed in the step tablets developed at the beginning and those developed at the end. In particular, the number of solid layers of the positive type 23 plate became low.

Developer CD) Phenyl cellosolve 5 parts by weight Propylene glycol 3 parts by weight p-tert
-Butylbenzoic acid 15 parts by weight Perex NBL (anionic surfactant, 1 part by weight solids content 35%)
(manufactured by Kao Atlas Co., Ltd.) Potassium sulfite 10 parts by weight Potassium silicate aqueous solution 22 parts by weight Potassium hydroxide 15 parts by weight Water
900 parts by weight replenisher [G
] Potassium silicate aqueous solution Potassium hydroxide water 60 parts by weight 25 parts by weight 830 parts by weight Developer (H) Phenyl cellosolve 5 parts by weight Propylene glycol 6 parts by weight pt
art-butylbenzoic acid 18 parts by weight Perex NBL 15 parts by weight Potassium sulfite 10 parts by weight Potassium silicate aqueous solution 20 parts by weight Potassium hydroxide 30 parts by weight Water
800 parts by weight [Effects of the Invention] According to the present invention, the negative type 23 plate can be produced using a common developer for the negative type 23 plate and the positive type 23 plate, which are repeatedly used by replenishing the replenisher.
The stability of the developed finish is improved when the plate and the positive type 23 plate are developed in common.

Claims (1)

[Scope of Claims] A development process in which a negative-working photosensitive lithographic printing plate and a positive-working photosensitive lithographic printing plate are developed using an automatic developing machine and a negative/positive common developer that is repeatedly used by replenishing a developer replenisher. In the method, the developer replenisher contains at least the following (A) and (
B), and is characterized in that the negative-working photosensitive planographic printing plate and the positive-working photosensitive planographic printing plate are replenished at different ratios of replenishment amounts of (A) and (B). A method for developing printing plates. (A) Aqueous solution containing alkali silicate. (B) A solution containing at least one selected from nonionic surfactants and cationic surfactants.