JPS63200154A - Developing solution for photosensitive planographic printing plate which can commonly process negative type and positive type - Google Patents

Abstract

PURPOSE:To permit satisfactory development of negative and positive type PS plates with one kind of developing soln. by using the developing soln. contg. an alkali agent, water soluble reducing agent, organic carboxylic acid or the salt thereof and nonionic or cationic surfactant and specifying the pH range thereof. CONSTITUTION:The developing soln. which contains the alkali agent, the water reducible reducing agent, the org. carboxylic acid or the salt thereof and the nonionic or cationic surfactant and has the pH ranging 11.5-13.5 is used for the water-based alkaline developing soln. which commonly processes the negative and positive type photosensitive planographic printing plates (PS plates). The developability, printing performance and developing speed in the case of developing the negative type PS plate and positive type PS plate with one developing soln. (for example, in the case of nondiscriminately developing the negative and positive type PS plates with the same developing soln. by using an automatic developing machine) are thereby improved. In addition, the workability is excellent as there is substantially no bubbling.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a developer and a developing method for photosensitive lithographic printing plates, and in particular to negative-working photosensitive lithographic printing plates and positive-working photosensitive lithographic printing plates. This invention relates to a developing solution that can commonly develop a common plate.

[Prior art]

Conventionally, negative-working photosensitive lithographic printing plates (hereinafter referred to as negative-working 18th edition) and positive-working photosensitive lithographic printing plates (hereinafter referred to as positive-working 28th edition) have different developer compositions. However, it was possible to develop the film in a suitable manner. Even if development could be performed using a developer other than a dedicated developer, a lithographic printing plate with sufficient performance could not be obtained, and the negative 18th plate and the positive 28th plate could be commonly processed using a developer with the same formulation. The reality is that this is practically impossible.

JP-A No. 60-64351 describes a common developing method in which both a negative 25th plate and a positive 28th plate are developed using one automatic developing machine. However, in this technique, development is performed sequentially using each dedicated developer in separate development zones, and development is not performed with a developer having the same formulation.

Therefore, since a dedicated developer is used for each, solution management is troublesome and it is difficult to perform stable development over a long period of time.

A developer that performs common development with one type of developer is JP-A-2007-10203. Organic solvents such as ethylene glycol monophenyl ether or ethylene glycol monobennorether, silicates, alkali metal hydroxides, anionic surfactants, and water-soluble reducing agents. It consists of

However, such a developer is very prone to foaming, and the development speed was not sufficient for the negative type 28 plate. On the other hand, when the positive type 28 plate was developed, the development latitude was such that the development result was extremely variable, and a part of the image area was easily immersed during development and was easily lost. This tendency is more noticeable when the development time is slightly extended or when the development temperature is slightly higher than the prescribed temperature, resulting in loss of image details and problems when printing. This may cause poor printing durability.

[Purpose of the invention]

An object of the present invention is to provide a developer that can satisfactorily develop Negative type and Bot type 23 plates with one type of developer.

Another object of the present invention is to provide a developer having a wide development latitude.

Another object of the present invention is to provide a developer with less foaming.

Another object of the present invention is to provide a developer capable of rapidly developing Ne-type and B-type 23 plates.

[Structure of the invention]

As a result of extensive studies, the present inventors found that in an aqueous alkaline developer that commonly processes negative 18th plates and positive 28th plates, the developer contains an alkaline agent, a water-soluble reducing agent, an organic carboxylic acid or its salt, The above object of the present invention could be achieved by using a developer containing a nonionic or cationic surfactant. The present invention will be explained in detail below.

Examples of the alkaline agent contained in the developer of the present invention include sodium silicate, potassium silicate, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate, ammonium diphosphate, Inorganic alkaline agents such as sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc., organic alkaline agents such as mono-, triethanolamine, and tetraalkylammonium hydroxide, and organic ammonium silicate, etc. Useful. Among these alkaline agents, alkali metal silicates are particularly preferred.

The content of alkaline agent in the developer is 0.05 to 20
A range of % by weight is suitable, more preferably 0.1 to 1
It is in the range of 0% by weight.

The water-soluble reducing agent used in the developer of the present invention includes organic and inorganic reducing agents.

Examples of organic reducing agents include phenolic compounds such as hydroquinone, methol, and methoxyquinone, and amine compounds such as phenylenenoamine and phenylhydrazine. Examples of inorganic reducing agents include sodium sulfite, potassium sulfite, ammonium sulfite, and sulfite. Phosphates such as sodium hydrogen, potassium hydrogen sulfite phosphate, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium dihydrogen phosphite, dipotassium hydrogen sulfite, hydranone, sodium thiosulfate, dithionite Although sodium and the like are mentioned above, the reducing agent that is particularly effective in the present invention is sulfite.

In the present invention, the water-soluble reducing agent includes alkali-soluble, and these water-soluble reducing agents have a content of 0.1 to 10 fi%, more preferably 0.5 to 5.
It is contained in a range of % by weight.

The organic carboxylic acid contained in the developer of the present invention is preferably an aliphatic carboxylic acid having 6 to 20 carbon atoms, and 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. The above aliphatic carboxylic acid is preferably used as a sodium or potassium salt or an ammonium salt in order to improve its water solubility.

Specific compounds of aromatic carboxylic acids include benzoic acid, 0-chlorobenzoic acid, p-chlorobenzoic acid, 0-hydroxybenzoic acid, p-hydroxybenzoic 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-su7toic acid, 3-hydroxy-2-su7)
Among these, hydroxynaphthoic 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 content of aliphatic carboxylic acid and aromatic carboxylic acid added to the developer used in the present invention is not particularly limited;
If it is lower than 30% by weight, the effect is not sufficient, and if it is lower than 30% by weight.
Not only is it impossible to improve the effect further, but also the dissolution may be hindered when other additives are used together.

Therefore, the amount added is preferably 0.1 to 10% by weight,
More preferably, it is 0.5 to 4% by weight.

Furthermore, the developer according to the present invention contains a nonionic or cationic surfactant.

Various compounds can be used as the nonionic surfactant, but they can be broadly classified into polyethylene glycol compounds and polyhydric alcohol compounds, with polyethylene glycol compounds being more preferably used. Among them, the oxyethylene unit has a repeating structure of 3 or more, and the IILB value (Hydrophile-L
A nonionic surfactant having a ipophile Balance of 5 or more, more preferably 10 to 20 is suitable. That is, the above-mentioned preferred nonionic surfactant is represented by the following general formula.

4≦7)\R0(CH2CHzO)nH I3 TomiR-0-(CH2CHO)11- (CH2CHzO)
nHIO(CJ-0)a-(CJiO)b-(C21(
40) eHIO-(CIIzCHzO)nH (Here, n and logictaybte*X+3' are all 1 to 4
(representing an integer of 0) Specific examples of the compound represented by the above general formula are as follows.

For example, 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 cetyl ether, polyoxyethylene phenyl ether, polyoxy Ethylene octylphenyl ether, polyoxyethylene stearylamine, polyoxyethylene oleylamine, polyoxyethylene stearamide, polyoxyethylene oleic acid amide, polyoxyethylene castor oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, poly Oxyethylene monolaure 11 polyoxyethylene monostearate, polyoxyethylene glyceryl monooleate, polyoxyethylene glyceryl monostearate, polyoxyethylene propylene glycol monostearate, oxyethylene oquine propylene block polymer, nostyrenated phenol poly Examples include ethylene oxide adduct, tribenzyl 7-ester polyethylene oxide adduct, octylphenol polyoxyethylene polyoxypropylene adduct, glycerol monostearate, sorbitan monolaurate, and polyoxyethylene sorbitan monolaurate.

The amount of these nonionic surfactants added is o, ooi~5
1% by weight, more preferably in the range of 0.01-0.3% by weight.

The weight average molecular weight of these nonionic surfactants is preferably 300 to 50,000, particularly preferably 500 to 50,000.
~5000 range.

In the present invention, the nonionic surfactants may be used alone or in combination of two or more.

The cationic surfactant used in the present invention includes various compounds, including organic amine compounds and quaternary ammonium salt compounds.

Examples of organic amine compounds include polyoxyethylene alkylamine, N-alkylpropylenezamine, N-
-Alkyl polyethylene polyamine, N-alkyl polyethylene polyamine dimethyl sulfate, alkyl biguanide, long chain amine oxide, alkylimigzoline, 1-
Hydroxyethyl-2-alkylimigzolin, 1-7
Cetylamide/ethyl-2-furkylimigzolin, 2-
Examples include furkyl-4-methyl-4-hydroxymethyloxazoline.

Examples of quaternary ammonium salt compounds include long-chain
Amine salts, alkyltrimethylammonium salts, noalkyldimethylammonium salts, alkylmethylammonium salts, alkyldimethylbennolammonium salts, alkylpyridinium salts, alkylquinolinium salts, alkylisoquinolinium salts, alkylpyridinium sulfates, Amidomethyl birizonium salt, acylaminoethyldiethylamine salt, acylaminoethylnoethylammonium salt, furkyl 7 midobrovir dimethylbennolammonium salt, fatty acid polyethyleneboriacolaminoformylmethylpyrizonium salt, stearoxymethylpyrizo Examples include fatty acid triethanolamine, fatty acid triethanolamine formate, trioxyethylene fatty acid triethanolamine, fatty acid butylaminoethanol, cetyloxymethylpyridinium salt, p-isooctylphenoxyethoxyethylbenzylammonium salt, and the like.

Among these compounds, cationic surfactants such as water-soluble quaternary ammonium salts are particularly effective, and include alkyltrimethylammonium salts, alkyldimethylpensylammonium salts, ethylene oxide-added ammonium salts, and the like. Polymers having cationic components as repeating units are also generally cationic surfactants and are effective. In particular, a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic monomer can be suitably used. The amount of the cationic surfactant added is the same as that of the nonionic surfactant / 11 0
1-t! +m801 to n 61 41 1
/1-)A Al-A is in the range of 48%. Further, the weight average molecular weight 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, but 2
You may use more than one species in combination.

Furthermore, in the present invention, the effects of the present invention can be obtained even when a nonionic surfactant and a cationic surfactant are used in combination.

Although additives may be added to the developer of the present invention, organic solvents having a solubility in water of 10% by weight or less are particularly effective.

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 ethyl butyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols such as ethylene glycol motuptyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-7 methyl alcohol, and methyl amyl alcohol fulkyl-substituted aromatic hydrocarbons such as xylene; halogenated hydrocarbons such as methylene cyclolide, methylene cyclolide, and monochlorobenzene. One or more of these organic solvents may be used. Among these organic solvents, ethylene glycol monophenyl ether and ethylene glycol benol ether are particularly preferred.

The organic solvent is an excellent additive for improving the developability of both negative and positive PS plates, but at the same time it has the disadvantage of degrading the film in the image area for positive type 28 plates. It also has Since the positive type 28 plate does not undergo a crosslinking reaction during exposure unlike the negative type 28 plate, the film deteriorates significantly when development is excessive, and the degree of deterioration becomes even greater in the presence of organic solvents. As a result of intensive studies, the present inventors found that in order to prevent the deterioration of the film during development of the positive 28 plate and to develop the negative 28 plate well, the inventors found that non-ionic or It has been found that the cationic surfactant is preferably contained in a range of 0.001 to 10% by weight.

The pH of the developer according to the present invention is from 11.5 to 13.5 l.
It is around a. Such high pH (pH 11.5 or higher)
When a negative 28 plate is developed, some types of plates may be smeared during printing even though they are developed. The degree of contamination depends on pn, and the higher pi is, the more likely it is to be contaminated. In order to develop the negative type 28 plate well at such a high pH and eliminate stains during printing, it is very effective to include sulfite in the developer, and anionic surfactant. The addition of is particularly effective in accelerating the development of negative type 28 plates using polymers with low acid values.

The developer of the present invention having such a composition has a pH of 11.5 to 13.5 as described above, and has a pH other than this.
In the 11 range, no effective results can be obtained when common development is performed on the negative 28th plate and the bottom 28th plate. That is, if the pH is lower than 11.5, the positive type28
The development of the plate tends to be insufficient, and if the pH exceeds 13.5, the developability of the negative 28 plate deteriorates. In the case of positive type 28 plates, which tend to leave behind films and cause ink stains during printing, excessive development can cause loss of image details and corrosion of the grained surface. It becomes easier.

A particularly preferred embodiment of the developer of the present invention uses an alkali metal silicate as the alkali agent, a sulfite as the water-soluble reducing agent, and a 1-alkanoic acid having 6 to 20 carbon atoms and a hydroxynaphthoic acid as the organic carboxylic acid. At least one type of nonionic or cationic surfactant selected from a nonionic surfactant containing an ethylene oxide group and a cationic surfactant containing a quaternary ammonium salt is used as a nonionic or cationic surfactant. and the content of the surfactant is in the range of 0.01 to 1.0% by weight, and in this embodiment, the effects of the present invention are particularly
It is tIF.

In addition, the following additives may be added to the developer used in the present invention in order to further improve the developing performance.
Neutral salts such as I, KBr, etc., Imashi-F agents such as ECT8 and NT^ described in JP-A-59-190952, JP-A-59-1909
(Co(N)13) described in Publication No.-121336
complexes such as 5c1s, ampholytic polymer electrolytes such as copolymers of vinylbennortrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, lithium chloride as described in VF JP-A-58-59444, etc. organic lithium compounds such as lithium benzoate described in Japanese Patent Publication No. 50-34442,
If! containing Si, Ti, etc. described in JP-A-59-75255! 1 Metallic surfactant, JP-A-59-84241
Examples thereof include organic boron compounds described in the above publication.

The 25th edition 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 change upon exposure or subsequent development treatment. For example, there is a difference in solubility in a developer due to exposure, a difference in intermolecular adhesion between before and after exposure, a difference in affinity for water and oil due to exposure or subsequent development, and A device that can form an image area using a photographic method, and JP-A-55
- 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. Typical positive-type compounds that become alkali-soluble upon exposure include 0-quinone diat compounds, acid-decomposable ether compounds, and ester compounds.

Aromatic noazonium salts and the like are examples of negative-type compounds whose solubility decreases upon exposure to light.

Specific examples of 0-quinone di7dide 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.
, No. 454,400, No. 3,544,323, No. 3.
No. 573,917, No. 3,674,495, No. 3,7
No. 85,825, British Patent No. 1,227,602, No. 1
, No. 251,345, No. 1,267.005, No. 1
, 329, 888, 1,330,932, and German Patent No. 854°890. Examples of acid-decomposable compounds include JP-A-60-37549, JP-A-60 (0247), and JP-A-60-3625. The present invention can be preferably applied at least to the 25th plate in which these compounds are used alone or in combination as photosensitive components.

These photosensitive components include 0-quinone di7idocarboxylic acid esters of aromatic hydroxy compounds or 0-quinonenoacetocarboxylic acid esters and 0-quinone di7idocarboxylic acid esters of aromatic hydroxy compounds and
+/includes 0-quinone diacid sulfonic acid or 0-quinone noanodocarboxylic acid amide, and those in which these 0-quinone diacid compounds are used alone, and those in which they are mixed with an alkali-soluble resin and this mixture is provided as a photosensitive layer. is golden.

The alkali-soluble resin includes /borac type phenol resin, and specifically includes phenol formaldehyde resin, cresol formaldehyde resin, phenol-cresol mixed formaldehyde resin, cresol xylenol mixed formaldehyde resin, and the like. Furthermore, as described in JP-A-50-125806, in addition to the above phenol tree layer, a phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms such as t-butylphenol formaldehyde resin is added. A combination of a condensate with formaldehyde can also be applied.

If necessary, additives such as dyes, plasticizers, and components imparting printout performance can be added to the photosensitive layer containing an 0-quinonediaside compound as a photosensitive component.

The present invention can be applied to an amount per unit area of a photosensitive layer containing an 0-quinonediaside compound as a photosensitive component, preferably in the range of about 0.5 to 7 g/12.

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. 7364/1983. Phenol salts or fluorocapric acid salts of p-diazophenylamine, etc., combinations of 3-methoxydiphenylamine-4-noazonium chloride, 4-nitrocyphenylamine, and formaldehyde described in Japanese Patent Publication No. 49-48001. Diazo resin consisting of organic solvent soluble salt of polycondensate, 2-methoxy-4-hydroxy-5 condensate of p-cyazinophenylamine and formaldehyde
Examples include -benzoylbenzenesulfonate, tetrafluoroborate of a condensate of p-diazophenylamine and formaldehyde, and hexafluorophosphate.

The present invention can be preferably applied at least to negative photosensitive planographic printing 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 Sheftsuk, polyvinyl alcohol derivatives, copolymers having an alcoholic hydroxyl group in the side chain described in JP-A-50-118802, and JP-A-50-118802.
A copolymer having a 7-enolic hydroxyl group in a side chain described in No. 5-155355 can be mentioned.

These resins are copolymers containing a small amount (both 50% by weight) of structural units represented by the following general formula, general formula R
.

(CH2-C) "COO(CH2CHO) n H (wherein, R+ 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 an integer from 1 to 1O. ) 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 an acid value of 10 to 200. Includes polymer compounds with

Additives such as dyes, plasticizers, and components imparting printout performance can be added to the photosensitive layer of the negative photosensitive lithographic printing plate to which the developer and development method of the present invention are applied.

The amount of the photosensitive layer per unit area is small (both 0.1 to 7
The present invention can be applied to the range of "g/yz".

The support used in the photosensitive lithographic printing plate is as follows:
Paper, plastic (e.g. polyethylene, polypropylene, polystyrene, etc.), laminated paper, aluminum (
(including aluminum alloys), plates of metals such as zinc, copper, etc., films of plastics such as cellulose dipartite, cellulose dipartite, cellulose propionate, polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyvinyl acetal, etc. Examples include paper laminated or vapor-deposited with the metals mentioned above, and 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 improving adhesion to the photosensitive layer.

ψnInari Shitsuji Sojil÷-Aiichiro (Translated by Praley method, ball polishing method, electrolytic etching, chemical etching,
Mention may be made of methods such as liquid honing, sandblasting, and combinations thereof, preferably brush polishing methods, electrolytic etching, chemical etching and liquid honing, among which roughening methods particularly include the use of electrolytic etching. Particularly preferred electrolytic baths used in electrolytic etching include aqueous solutions containing acids, alkalis, or their salts, or aqueous solutions containing organic solvents, particularly hydrochloric acid, nitric acid, or salts thereof. An electrolytic solution containing the following 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 preferably, a method of treatment in a bath containing sulfuric acid or phosphoric acid can be mentioned.

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

In addition, the development method using the developer according to the present invention includes, in addition to the development process, if necessary, after the development process, a development stop process (the stop process solution includes a disposable method or a cyclic use method), Each individual processing step of the chemical treatment step, a development stop treatment step and a desensitization treatment step following it, a treatment step that combines a development treatment step and a desensitization treatment, or a development stop treatment step and a desensitization treatment step. For example, a combination of the processing steps disclosed in Japanese Patent Application Laid-Open No. 54-8001 may be included.

In addition, when developing the negative type and the positive type 28 plate in the present invention with the same developer, conditions other than the developer composition (e.g., development temperature, development time, etc.) may be changed arbitrarily between the negative type and the bottom type. be.

〔Example〕

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

Example 1 Ethylene glycol monomethyl ether 3 under nitrogen flow
00 parts by weight were heated to 100°C, and thereinto were added 150 parts by weight of 2-hydroxyethyl methacrylate, 90 parts by weight of acrylonitrile, 79.5 parts by weight of methyl methacrylate, 10.5 parts by weight of methacrylic acid, and 1.2 parts by weight of benzoyl peroxide.
Parts by weight of the mixed solution were added dropwise over 2 hours.

Fifteen minutes after the completion of the dropwise addition, 300 parts by weight of ethylene glycol monomethyl ether and 0.3' part by weight of benzoyl peroxide were added, and the mixture was allowed to react for 4 hours. After the reaction was completed, the copolymer was precipitated by diluting it with methanol and pouring it into water.
Vacuum dried at °C. The acid value of this 2-hydroxyethyl methacrylate copolymer (1) was 21.

A 28 aluminum plate with a thickness of 0.151 m was immersed in a 10% aqueous solution of tertiary sodium phosphate kept at 80°C for 3 minutes to degrease it, and after graining with a nylon brush, it was soaked in 3% sodium flumate at 60'C. It was desmutted with an aqueous solution. The aluminum plate was anodized in 20% sulfuric acid at a current density of 2^/da2 for 2 minutes and then treated with a 25% aqueous solution of sodium silicate at 70''C for 1 minute.

This aluminum plate was coated with Niggi's photosensitive liquid and heated to 100°C.
After drying for 2 minutes, a negative type 28 plate was obtained.

・2-hydroxyethyl methacrylate copolymer (1)
...87 parts by weight 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate of condensate of p-diazodiphenylamine and paraformaldehyde ...10
Parts by weight: Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd., triphenylmethane oil-soluble dye) 3 parts by weight 2-methoxyethanol 600 parts by weight Meta/- 600 parts by weight
Ethylene dichloride: 600 parts by weight The dry coating weight was 2.51 F/I2.

I attached a step wedge and a negative original image with halftone dots to this 23rd edition and made it 70cm with a 307 Nbare carbon arc lamp.
The image was exposed for 40 seconds from a distance of .

On the other hand, as a positive type PS plate, U.S. Patent No. 3,635,709
1 part by weight of 7-toquinone-1,2-noacyto-5-sulfonic acid ester of polyhydroxyphenyl obtained by condensation polymerization of acetone and pyrogallol as described in Example 1 of the specification and 7-borac type cresol formaldehyde. 2 parts by weight of resin, 0.03 of Oil Blue #603
20 parts by weight of acetic acid-2-methoxyethylene and 2 parts by weight.
A photosensitive solution prepared by dissolving in 0 parts by weight of methyl ethyl ketone was applied to a grained and anodized aluminum plate and dried at 80'C for 2 minutes to obtain a dry coating type fi2.5g/
A 23rd plate of ``+++'' was obtained. A step wedge original was brought into close contact with this positive type 28th plate, and the image was exposed for 60 seconds from a distance of 70 cm using a 30 ampere carbon arc lamp.

As above, the exposed negative type and positive type 28 plates were developed as shown below. (^) using automatic development fiPsP-860 (
A developing process was carried out at 27° C. for 20 seconds using Konishiroku Photo Industry Co., Ltd.).

In addition, the pH of the developer is set to 12.0 with N a Otl at the time of use.
Adjusted to 90.

Developer (^) (invention) - Silicic acid sorb JIS No. 3 3.0 parts by weight - Potassium sulfite 0.5 parts by weight
3-hydroxy-2-su7toic acid 2.0 parts by weight
Nirafur 80-20 (nonionic surfactant polyethylene dioxyoleyl ether manufactured by Nikko Chemicals Co., Ltd.) 0.1 part by weight, phenyl cellosolve 1.0 weight m, potassium hydroxide 1. O3l parts/water
When the negative 28th plate and the bottom 28th plate were treated indiscriminately with 92.5 parts by weight of the above developer (^), good printing plates without any problems were obtained. Further, almost no foaming was observed in the developing tank, washing tank, and each liquid tank of the automatic developing machine.

Examples 2 to 7, Comparative Examples 1 to 3 An aluminum plate with a thickness of 0.24'II was immersed in a 20% aqueous sodium phosphate solution to defertilize it, and then immersed in a 0.2N hydrochloric acid bath for 3^/, After electropolishing at a current density of 2, it was anodized in a sulfuric acid bath. At this time, the amount of anodic oxidation is 4g/l
Met. Further, the plate was sealed with an aqueous sodium metasilicate solution, and an aluminum plate used for a lithographic printing plate was coated to obtain a negative type 28 plate, and a photosensitive fiB was coated to obtain a bottom type 28 plate. Coating was performed using a rotary coater and dried at 100° C. for 4 minutes. Coating film thickness weight is 2.5g/m2 for both plates.
(Photosensitive liquid A) N-(4-hydroxyphenyl) methacrylamide:
7 Acrylonitrile: Ethyl acrylate: Methacrylic acid = 27:33:41: 6 (weight ratio) copolymer (acid value 80) -5,0°・p-no7zoν phenylamine Hexafluorophosphate of paraformaldehyde condensate
...0.5g Sherimar AC-1OL (
Product name, manufactured by Nippon Junyaku Co., Ltd., acrylic acid polymer) ・・・0.059 ・Tartaric acid ・・・・・・0.05゜・V) Riabinia Blue BOH (Product name, Fukadogaya Chemical Industry Co., Ltd. Co., Ltd., dye)...
...O, 11?・/Borac tree ffff (pp 3121) (Gunei Chemical Co., Ltd.!l) ・・・・・・o, tsy・Pluronic-64 (Product name, manufactured by Asahi Denka Co., Ltd., surfactant)...・・・・・・
0.005g ・Methyl cellosolve ・・・・・・100i1
(Photosensitive liquid B) ・Condensate of capto+7-(t4)-cyanodo-(2)-5-sulfonic acid chloride and resorcinol-benzaldehyde resin 3.5 g ・1-Cresol-formaldehyde novolac resin '
MP-707” (manufactured by Gunei Chemical Industry Co., Ltd.)
9g ・S7) Quinone-(1,2)-noacyto-(2)-4-
Sulfonic acid chloride ・・・0.15g・Victoria Pure Blue BOH (Product name, manufactured by Fukadogaya Chemical Co., Ltd., dye)・・・・
...0.2 g No. 74 Lucerosolf vase +-1009 The plate thus obtained was exposed using a 2 Km metal halide lamp through a step wedge with a density difference of 0.15. Thereafter, development was carried out using the developer shown in Table 1 in an automatic processor at 30° C. while changing the development time, and the results shown in Table 2 were obtained.

The pH of the developer should be adjusted to 1 after adding the additives and immediately before use.
It was adjusted to 12.85 with 0% NaOH or 1N-HCl.

In Table 2, the N version is the winter type 28 version, and the P version is the Bon type 1 version.
8th edition, and the gradation is the result of evaluating the difference between the number of solid steps and the number of clear steps using developing ink 5PO-1 (manufactured by Konishiroku Photo Industry Co., Ltd.). In addition, over-developability is determined by the developer of the present invention, as is clear from the results shown in Table 2 when developing a positive PS plate in twice the time of standard development (here, clear 5 steps). The developer can develop both the negative 23rd plate and the bottom 28th plate faster than conventional developers, has a wide development latitude, and has less foaming. Further, among the developing solutions of the present invention, a developing solution containing 3-hydroxy-2-7toic acid as the organic carboxylic acid is particularly excellent.

On the other hand, the developing solution of Comparative Example (1) did not contain an organic carboxylic acid, so the developability of the negative type 28 plate was extremely poor.

The developer of Comparative Example (2) does not contain an organic carboxylic acid and a nonionic surfactant, but instead contains a tenion type surfactant, but this developer has a slight development problem compared to the negative type 28 plate. It was defective, and for the Bot PS type, detailed images were likely to be lost during overdevelopment. With the developer of Comparative Example (3), the negative 28 plate was smeared during printing, which caused a practical problem.

〔Effect of the invention〕

According to the present invention, when developing the negative 23rd plate and the positive 28th plate with a developer (for example, developing the negative 28th plate and the positive 28th plate indiscriminately with the same developer using an automatic developing machine) The developability, printing performance, and development speed of (case) are improved. Furthermore, the developer of the present invention has excellent workability since it hardly causes foaming.

Normally, rapid development involves making the developer more concentrated, raising the processing temperature, or adding additives that promote development, such as organic solvents, but no matter which method you use, the development process will be faster. Conventionally, the latitude was narrow, making it difficult to obtain stable and good images. However, in the present invention, even if rapid development is performed, a good image can be stably obtained.

In addition, the image area is often attacked during the development of positive type 28 plates, and even slight overdevelopment can cause the image to be missing or the film to become thin. Although adhesion occurs when a solvent is contained, according to the present invention, good common development can be achieved even in the presence of an organic solvent.

Claims (7)

[Claims] (1) In an aqueous alkaline developer commonly used to process negative-working photosensitive lithographic printing plates and positive-working photosensitive lithographic printing plates, the developer contains an alkaline agent, a water-soluble reducing agent, an organic carboxylic acid or its salt, and a non-alkaline agent. A developer for photosensitive planographic printing plates, which contains an ionic or cationic surfactant and has a pH in the range of 11.5 to 13.5. (2) The developer according to claim 1, wherein the alkaline agent is an alkali metal silicate. (3) The developer according to claim 1 or 2, wherein the reducing agent is a sulfite. (4) The developer according to claim 1, 2 or 3, wherein the organic carboxylic acid is an aliphatic carboxylic acid having 6 to 20 carbon atoms. (5) The developer according to claim 1, 2, 3, or 4, wherein the organic carboxylic acid is an aromatic carboxylic acid having a benzene ring or a naphthalene ring. (6) Claims 1, 2, and 3, characterized in that the amount of the nonionic or cationic surfactant added is in the range of 0.001 to 5% by weight. The developer according to item 4 or 5. (7) The developer according to claim 1, 2, 3, 4, 5, or 6, wherein the developer contains an organic solvent.