JPS6258254A - Processing method for photosensitive lithographic plate - Google Patents

Abstract

PURPOSE:To prevent wasteful use of water, by washing a photosensitive lithographic plate with repeatedly used washing water after the plate is developed with the same repeatedly used developing solution. CONSTITUTION:A used developing solution is returned to a developing solution storing tank 14 after it is squeezed by means of a squeezing roller pair 5 and circularly used. A washing section is composed principallyof a washing tank 2, carrying roller pair 4', tandem roller pair 6', squeezing roller pair 5', and water supplying nozzles 8' and supplies circularly used washing water, which is circularly used by means of a washing water supplying pump 11, to a lithographic plate coming out from a developing section from the nozzles 8'. A post-processing section is composed principally of a post-processing tank 3, carring rollers 4'', squeezing rollers 5'', tandem rollers 6'', and post-processing solution supplying nozzles 8'' and the post-processing solution stored in a post- processing solution tank 16 is supplied to the lithographic plate passed through the washing section from the nozzles 8'' by means of a post-processing solution supplying pump 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for processing a photosensitive lithographic printing plate, and more specifically to a method for processing a photosensitive lithographic printing plate using washing water that is repeatedly used after development. This relates to a processing method.

[Conventional technology]

Exposed photosensitive lithographic printing plate (hereinafter simply referred to as PS plate)
When processing a large number of sheets, it is common to use an automatic processor, but when processing negative PS plates and positive 25 plates in common with one automatic processor, the processing PS
The developer had to be replaced each time depending on the type of plate, which was inefficient and economically wasteful.

JP-A No. 57-192952 discloses a method of processing negative and positive 25 plates with the same developer, but in this case, after development, a large amount of washing water is used to wash the plates under running water. . In this case, there are disadvantages such as increased costs due to the use of a large amount of water and environmental pollution caused by washing waste water.

In addition, methods that simply omit the water washing step after developing the PS plate are disclosed in JP-A-54-8002 and JP-A-55-11504.
Although it is described in Publication No. 5, in order to process negative-type and positive-type PS plates with the same automatic developing machine using this method, it is necessary to change the developer depending on the type of PS plate as in the previous period. This inevitably led to a decline in work efficiency and economy.

Furthermore, JP-A-57-158643, JP-A No. 59-5843
No. 1 and No. 59-57242, etc., describe a method of repeatedly using washing water, but although this also improves the problem of wastewater and water resources, the PS
The problem of developer exchange between plates remained unsolved.

[Problem to be solved by the invention 1 As mentioned above, although many methods have been proposed for processing PS plates that do not waste water, there are still none that are satisfactory. No method has been developed that can commonly process Nega-type and Bon-type PS versions without consuming them.

It is an object of the present invention to provide a PS plate processing method which can improve the above-mentioned drawbacks of the prior art and can commonly process negative-type PS plates and positive-type 18 plates, while suppressing the generation of waste water as much as possible.

Still another object of the present invention is to provide a PS plate processing method that allows mixed processing of negative type and positive type 18 plates and has a low processing cost.

[Means for Solving the Problems 1] As a result of intensive research, the present inventors have found that the above purpose is to produce a negative photosensitive lithographic printing plate and/or a positive photosensitive lithographic printing plate using an automatic processor. In a processing method in which the negative and/or positive photosensitive lithographic printing plates are automatically transported and developed, the negative and/or positive photosensitive planographic printing plates are developed with the same developer that is used repeatedly, and then washed with water that is used repeatedly. It has been found that this can be achieved by a method of processing a photosensitive lithographic printing plate, which is characterized by processing.

The present invention will be explained in detail below.

The PS plates covered by the present invention are those in which a photosensitive layer whose solubility changes upon irradiation with light is coated on a support, or a soluble layer in which an imager renost layer can be formed by an electrophotographic method or the like. It is provided on a support.

Supports used for the above PS plates include paper, plastics (e.g. polyethylene, polypropylene, polystyrene, etc.), laminated paper, metal plates such as aluminum (including aluminum alloys), zinc, copper, etc. Films of plastics such as acid cellulose, cellulose tripartite, cellulose propionate, polyethylene teretalate, polyethylene polypyrene, polycarbonate, polyvinyl acetal, etc.; paper or plastic laminated or vapor-deposited with metals such as the above. films, aluminum or chrome-plated copper plates, etc.;
Aluminum and aluminum-coated composite supports are preferred.

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

Examples of surface roughening methods include generally known methods such as brush polishing, ball polishing, electrolytic etching, chemical etching, liquid honing, sandblasting, etc., and combinations thereof, preferably brush polishing, electrolytic etching, and chemical etching. These include target etching and liquid honing.
Among these, surface roughening methods involving the use of electrolytic etching are particularly preferred.

The electrolytic bath used in electrolytic etching is an aqueous solution containing an acid, an alkali, or a salt thereof, or an aqueous solution containing an organic solvent. Electrolytes are preferred.

Furthermore, the aluminum plate subjected to the surface roughening treatment is desmutted with an acidic or alkaline aqueous T# solution, if necessary.

It is desirable that the aluminum plate obtained in this manner be subjected to an anodizing treatment, and particularly preferred is a method of treatment with a solution containing sulfuric acid or phosphoric acid.

Furthermore, if necessary, surface treatment such as pore sealing treatment and immersion in an aqueous solution of potassium zirconate can be performed.

The photosensitive composition of the PS plate used in the present invention contains a photosensitive substance as an essential component, and the physical and chemical properties of the photosensitive substance do not change upon exposure or subsequent development treatment. For example, there are differences in solubility in developing solutions due to exposure, differences in intermolecular adhesive strength before and after exposure, differences in affinity for water and oil due to exposure or subsequent development, and A material that can form an image area by electrophotography can be used.

Typical photosensitive substances include, for example, photosensitive diazo compounds, photosensitive azide compounds, compounds with ethylenically unsaturated double bonds, epoxy compounds that polymerize with acid catalysts, and C-0- that decomposes with acids. Examples include compounds having a C-group.

Examples of photosensitive diazo compounds include 0-quinone diazide compounds, which are positive types that become alkali-soluble when exposed to light, and aromatic noazonium salts, which are negative types whose solubility decreases when exposed to light.

Specific examples of 0-quinonediazide compounds include, for example, JP-A-47-5303, JP-A-48-63802, and JP-A-48.
-638 (L1.

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. 48,120, No. 3,188,210, No. 3,45
No. 4,400.

3,544.323, 3,573,917, and 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 28th edition in which these compounds are used alone or in combination as photosensitive components. can be preferably applied.

These photosensitive components include 0-quinonediacidosulfonic acid ester or O-quinonediadocarboxylic acid ester of an aromatic hydroxy compound, and 0-quinonediacidosulfonic acid or 0-quinonediazidecarboxylic acid amide of an aromatic amino compound. Also included are those in which these O-quinonediaside 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.

The alkali-soluble resin includes a novolak type phenol resin, and specifically includes a phenol formaldehyde resin, a cresol formaldehyde resin, a phenol cresol mixed formaldehyde resin, a cresol xylenol mixed formaldehyde resin, and the like.

Furthermore, as described in JP-A No. 50-125806, in addition to the above-mentioned 7-enol resin, resins having 3 to 8 carbon atoms such as Heaptyl 7-enol formaldehyde resin
A combination of a phenol substituted with an alkyl group or a condensate of cresol and formaldehyde is also applicable.

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

The amount per unit area of the photosensitive layer containing the o-4 non-cyanodo compound as a photosensitive component is small (approximately 0.5 to 1 g/m).
The present invention can be applied to the following ranges.

There is no particular need to change the image exposure of the positive type 28 plate to which the method of the present invention is applied, and a conventional method may be used.

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-diazophenylamine and formaldehyde, as described in Japanese Patent Publication No. 7864/1983. 7xnol salt or fluorocaprate of p-diazodiphenylamine, etc., 3-7 toxydiphenylamine-4- described in Japanese Patent Publication No. 49-48001.
Diazo resin consisting of an organic solvent soluble salt of a copolycondensate of noazonium chloride, 4-nitrodiphenylamine and formaldehyde, 2-methoxy-4-hydroxy-5 condensate of p-diazodiphenylamine and formaldehyde Examples include benzoylbenzenesulfonate, tetrafluoroborate of a condensate of p-diazodiphenylamine and formaldehyde, and hexafluorophosphate.

The present invention can also be preferably applied to negative PS plates containing these as photosensitive components.

In addition to those in which these diazo compounds are used alone, the present invention is also applicable 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, copolymers having an alcoholic hydroxyl group in the side chain as described in JP-A-50-118802, such as derivatives of polyvinyl alcohol; Examples include copolymers having a phenolic hydroxyl group in a side chain.

These resins include copolymers containing at least 50% by weight of structural units represented by the following general formula;
R1 -(CIl□-C)-COO(CH2CHO) nH (wherein, R1 represents a hydrogen atom or a methyl group, R2 represents a hydrogen atom, a methyl group, an ethyl group, or a chloromethyl group, and n represents 1 to 10 ) and 1 to 80 mol% of monomer units having an aromatic hydroxyl group, and 5 to 90 mol% of acrylic ester and/or methacrylic ester monomer units, and 10 to 200 acid This includes polymeric compounds with valence.

The photosensitive layer of the negative PS plate to which the processing method of the present invention is applied may further contain additives such as dyes, plasticizers, and components imparting printout performance.

The amount per unit area of the photosensitive layer is at least 0.1 to
The present invention can be applied to the range of 78/vn'.

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

The developer used in the present invention is preferably an aqueous alkaline developer, and the alkaline agents used in the developer include sodium silicate, potassium silicate, sodium hydroxide, lithium hydroxide, dibasic sodium phosphate, and diphosphoric acid. Inorganic alkaline agents, such as sodium acid, dibasic potassium phosphate, dibasic potassium phosphate, dibasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc. Organic alkaline agents such as , di-, or triethanolamine and tetraalkylammonium hydroxide, organic ammonium silicates, 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 ~30 weight percent,
More preferably, it is 0.1 to 20 weight percent.

The developer used in the present invention can further contain an organic solvent. Examples of organic solvents include ethylene glycol monophenyl ether, benzyl alcohol, n-
Propyl alcohol and the like are useful. The content of the organic solvent in the developer composition is preferably 0.5 to 15% by weight, more preferably 1 to 5% by weight.
Weight percentage.

It is preferable that the developer further contains a surfactant, particularly an anionic surfactant. Examples of anionic surfactants include higher alcohol (Cs~0.2) sulfate ester salts [e.g., sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, [Teep].

11l-81J (trade name, manufactured by Shell Chemical Co., Ltd.), disodium alkyl sulfate 7ate, etc. 1, aliphatic alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate ester, etc.), alkylaryl sulfonate jiil ( For example, sodium salt of dodecylbenzenesulfonic acid, sodium salt of isopropylnaphthalenesulfonic acid, sodium salt of nonaphthalene disulfonic acid, sodium salt of metanitrobenzenesulfonic acid, etc.)
, sulfonic acid salts of alkylamides (e.g., C+J3sCONCHzCt12SOaNa
etc.), dibasic CH.

Examples include sulfonate salts of fatty acid esters (eg, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.). Among these, sulfonate salts are particularly preferably used.

The following additives can be added to such a developer in order to further improve the developing performance. For example, JP-A-5
8-751529 Publication 1m NoN aC1, KCI
Neutral salts such as KBr, chelating agents such as Er)TA and NTA described in JP-A-58-190952, JP-A-59-1909-
[Co(N11*)alcl described in No. 121336]
a, complexes such as CoCl2.6820, JP-A-50-51
: 7-ionic or amphoteric surfactants such as sodium alkylnaphthalene sulfonate and N-tetradecyl-N1N-dihydroxyethylbetaine described in Publication No. 124; nonionic interfaces such as tetramethyldecynediol described in U.S. Pat. No. 4,374,920; Activator, JP-A-55-9594
Cathonic polymers such as methyl chloride quaternized product of 1)-cyphthylaminomethylpolystyrene described in Publication No. 6, copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-56-142528, etc. Amphoteric polymer electrolyte, JP-A-57-1
Reducing inorganic salts such as sodium sulfite described in JP-A No. 92952, non-fi +7 tium compounds such as lithium chloride described in JP-A-58-59444, JP-A-50-34442
Organic lithium compounds such as lithium benzoate described in JP-A No. 59-75255, organometallic surfactants containing Si, Ti, etc. described in JP-A No. 59-84241, organic boron compounds described in JP-A-59-84241. Compound, European Patent No. 101
Examples include quaternary ammonium salts such as tetraalkylammonium oxide described in No. 010, organic solvents such as benzyl alcohol ethylene glycol monophenyl ether, and the like.

As a method for developing the 18th plate with such a developer, various conventionally known methods can be used.

That is, a method in which a developer is sprayed from a number of nozzles onto the image-exposed photosensitive layer of the 18th plate, a method in which the developer is immersed in a large amount of the developer, and a method in which the developer is applied to the surface of the light layer of the PSS plate source using a roller. Examples include methods. Further, after supplying the developer to the photosensitive layer of the 18th plate as described above, or while immersed in the developer, the surface of the photosensitive layer may be lightly rubbed with a brush or the like.

The developing conditions may be appropriately set according to the above-mentioned developing method, 18th plate, properties of the developer, etc. There may also be multiple developing tanks, and the developing solution or developing conditions may be different for each. .

The developer may be supplemented with a developer replenisher depending on the state of fatigue in order to compensate for fatigue caused by 18-plate processing or absorption of carbon dioxide in the air. Conventionally known methods for replenishing the replenisher may be used.

The lithographic printing plate thus obtained is then treated with repeated washing water.

In the present invention, the number of rinsing tanks used in the rinsing process using circulating rinsing water after the development process may be one, but it can also be divided into two or more tanks. Methods for bringing the developed lithographic printing plate into contact with the washing water in the washing tank include a shower method and a dipping method, but the shower method is preferably used.

When a plurality of washing tanks are provided, a combination of the shower method and the immersion method may be used, or only the shower method or only the immersion method may be used for all the tanks.

Further, in the washing step of the present invention, a washing promoting means can be provided. Washing promotion means include all physical means, chemical means, mechanical fishing means, etc. that promote water washing.

Mechanical fishing means include a method of rubbing with a rubbing member, for example, a method of rubbing by rotating a roller-shaped rubbing member, a method of rubbing by rotating and shaking a flat scraping member, a method of rubbing by rotating a flat scraping member, and a method of rubbing by rotating a flat scraping member back and forth and/or left and right. Examples include a method of rubbing by moving or a method of rubbing by moving a flat rubbing member back and forth and/or left and right.

Other washing promotion methods include, for example, blowing high-pressure air, irradiating ultrasonic waves, applying vibration to the 18th plate, and instantaneously heating the washing water on the PS plate by microwave irradiation. , or a method using heated circulating washing water. These washing promotion means may be used alone or in combination.

The time to add flushing promotion means is before supplying circulating flushing water.
It may be added during or after the supply, but it is preferably added during or after the washing water is supplied. Further, the circulating washing water supply means and the washing promoting means may be integrated. For example, when the washing promoting means is a disc-shaped brush and the washing water supply means is a nozzle, the nozzle may be provided at the center of the disc-shaped brush.

In the method of the present invention, the water washing treatment time of the developed 18th plate is preferably 5 seconds to 60 seconds.

It is also preferred that the circulating wash water used in the method of the invention be purified to prevent contamination. Examples of purification methods include replenishing washing water, filtration, and treatment with ion exchange resin or activated carbon. Adding a complexing agent to the circulating wash water is also a preferred method for preventing contamination of the circulating wash water.

In the present invention, after the water washing step, it is possible to perform treatment with a solution containing at least one of water and a non-chemical substance, such as an aqueous solution containing a surfactant (rinsing solution) or a desensitizing treatment solution.

Examples of surfactants used in the rinse solution include conventionally known nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, particularly anionic surfactants, For example, alkylbenzene sulfonic acid salts, dialkyl sulfonate succinates, and the like are preferably used.

Other rinsing liquids may include acids, water-soluble salts,
An aqueous solution containing a lipophilic substance etc. can be used.

As the desensitization treatment liquid, use an aqueous solution containing a water-soluble molecular compound and water as essential components, and containing surfactants, acids, water-soluble salts, wetting agents, organic solvents, preservatives and fungicides as necessary. I can do it.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Example 1 First, the following PS plates A and B were created and exposed.

In addition, % in the following text indicates weight %, and part indicates weight part.

(PS version A) A JTS 1050 aluminum plate with a thickness of 0.24 mm was immersed in a 2% aqueous sodium hydroxide solution, degreased, and then electrochemically roughened in a dilute nitric acid solution. After thorough washing, anodization treatment was performed in a dilute sulfuric acid solution to form an oxide film of 2.5 g/I'' on the surface of the aluminum plate.

The obtained aluminum plate was immersed in an aqueous solution of potassium zirconate 77 to make it hydrophilic, washed with water, dried, and then coated with a photosensitive solution having the following composition to a dry weight of 2,597-2, and dried. A PS version [A] was obtained.

The dimensions of the plate were 1003 x 800 I11-.

(Photosensitive liquid) Resorcinol-benzaldehyde resin 7-toquinone-1,2-cyanodo(2)-5-sulfonic acid ester (described in Example 1 of Ill'i Publication No. 1044/1983)... 1 part cresol-xylenol-formaldehyde resin 3 parts te
rt-butylphenol-formaldehyde resin...0.1 part Crystal violet (8, ^, S, F, 91 dye)
...0.03 part Victoria Pure Blue 〇〇〇 (dye manufactured by Hodogaya Chemical Industry Co., Ltd.) ...0.03 part Ethylene glycol monoethyl ether ...2
A transparent positive film was brought into close contact with this PS plate [A] and exposed for 60 seconds using a 2 kilowatt metal halide lamp from a distance of 702 O-C-.

[PS version B]

A JIS 1050 aluminum plate with a thickness of 0.24 mm was degreased by immersing it in a 20% aqueous sodium phosphate solution, electrochemically roughened in a dilute nitric acid solution, thoroughly washed, and anodized in a dilute sulfuric acid solution. 1.5g/ after oxidation treatment
-2 oxide film was formed on the surface of the aluminum plate.

The obtained aluminum plate was further immersed in an aqueous solution of sodium metasilicate for pore sealing, washed with water, and dried, then coated with the following photosensitive solution to a dry weight of 2.0 g/m'' and dried. The size of the 0th version obtained from PS version [B] was the same as that of PS version [A].

(Photosensitive liquid) Hexafluorophosphate of a condensate of p-noazinophenylamine and paraformaldehyde 1 part N-(4
-Hydroxyphenyl) methacrylamide copolymer (described in Example 1 of Japanese Patent Publication No. 57-43890) 10 parts Victoria Pure Blue B OH (Hodogaya Chemical (
Co., Ltd., dye) 0.2 parts Ethylene glycol monomethyl ether 100 parts This 18th edition [70ell with a transparent negative tape film tightly attached to B1 with a 2 kW metal halide lamp
Exposure was carried out for 30 seconds from a distance of .

Example 1 250 sheets each of the above-exposed 18 plates [A] and [B] were alternately processed in an automatic developing machine as shown in FIG.
℃ for 40 seconds.

FIG. 1 is a schematic side sectional view showing the development processing apparatus used in this example. The entire processing apparatus consists of a development processing section, a washing section, and a post-processing section. In this example, the post-processing section was filled with a desensitizing solution and used as a desensitizing section, but this machine can also be used as a surfactant processing section by putting other liquids, such as a surfactant solution. is also possible.

The development processing section mainly includes a development processing tank 1 and a pair of transport rollers 4.
, squeeze roller pair 5, skewer roller pair 6, receiver roller 7, developer supply nozzle 8, brush roller 9, developer supply pump 1
During development, a developer supply pump 10 is operated to supply developer from developer supply nozzles 8 to 18 plates. 13 is a pump for stirring the developer in the developer storage tank 14, and 17 is a heater for keeping the developer warm.

The liquid used in the development process is squeezed by a pair of squeezing rollers 5 and returned to the developer storage tank 14 for circulation.

The washing section mainly includes a washing treatment tank 2, a pair of conveyor rollers 4°,
It is connected to a pair of skewer rollers 6'', a pair of squeezing rollers 5'' and a water supply nozzle 8'', and is sent to the lithographic printing plate that has passed through the development processing section and is circulated by the rinsing water supply pump 11. The circulating washing water is supplied from a supply nozzle 8'.

The post-processing section mainly consists of a post-processing tank 3, a pair of transport rollers 4'', a pair of squeezing rollers 5'', a pair of skewer rollers 6'', and a post-processing liquid supply nozzle 8'', and the post-processing liquid stored in the post-processing liquid tank 16 is is supplied by the post-processing liquid supply pump 12 from the post-processing liquid supply nozzle 8'' onto the lithographic printing plate that has passed through the water washing section and removed.

A developer having the following composition was used.

(Developer) Potassium silicate aqueous solution (Si0□26%.

K, 013,5%) ...120 copies 8
6% Potassium hydroxide: 15.5 parts Potassium sulfite: 3 parts Pionine^-448 (sodium n-butylnaphthalene sulfonate, manufactured by Takemoto Yushi Co., Ltd.) 7 parts water
・・・・・・450
Put 151 liters of water to be circulated into the washing section, 8I/win.
The solution was circulated at a flow rate of 1, and was ejected from the nozzle 8', and each plate that had undergone the above development process was processed for 15 seconds. In addition, 6 u1 of washing water was replenished every time rice was processed.

Then, in the post-treatment section, treatment was carried out using a mucilage having the following composition as a desensitizing agent.

(Gum liquid) Gum arabic: 5 parts Dextrin: 15 parts Phosphoric acid (7 parts)
5%) ...0.3 part water
・・・・・・80
Part: Nonylphenol polyethylene oxide ether (6 moles of ethylene oxide): 1.0 part Stearic acid: 1.0 part Sorbitan monooleate: 1.0 part Diptyl 7 tallate 2.0 parts The above gum was circulated at a flow rate of 51/in and sprayed onto the plates from the nozzle 8', and each plate was treated for 10 seconds. Also, the gum solution was replenished at 8@1 every time rice was processed.

Although 500 18th plates were processed under the above conditions, no stains were observed during printing even in the 500th lithographic printing plate. Also, the gum solution was hardly tiring.

Comparative Example 1 The water washing section was removed from the automatic developing machine used in Example 1, and a desensitizing treatment was performed immediately after passing through the developing section. The conditions for development and desensitization were the same as in Example 1. Result 2
When printing the 28th plate of 00 sheets at the bottom of the process, scumming occurred in the image area, and the developer solution had become unusable and had to be replaced.

Comparative Example 2 The circulating water washing of the automatic developing machine used in Example 1 was stopped, and tap water was continuously supplied from a separately provided pipe to carry out running water washing. In other respects, when 500 plates were treated in the same manner as in Example 1, a good printing plate without stains was obtained, but more than 5 tons of water was consumed, and the same amount of waste water was generated, which was then purified. was necessary.

Example 2 The exposed 28th plate [AI and [B] are shown in FIG. 2) was processed using a developing solution having the following composition in an automatic developing machine at 25° C. for 20 seconds. PS version [B
] was developed for 30 seconds.

(Developer) Sodium silicate (Japanese Industrial Standard Sodium Silicate No. 3)
...100 parts Potassium hydroxide aqueous solution (48%) ...58 parts Sodium isopropylnaphthalene sulfonate (Aerosol O81 manufactured by American Cyanamid) ...10 parts Sodium sulfite ... ...5 parts pencil alcohol ...20 parts water
800 copies of the developed planographic printing plates [AI and [B] were then washed with circulating washing water in the washing section of an automatic developing machine. 151 was used as the washing water, and the water was circulated while being spouted from a nozzle onto the printing plate at a flow rate of 81/1/1 inch.

The washing process was carried out while the brush roller was running, and the processing time was 10 seconds for the lithographic printing plate rAl and 15 seconds for B1. Additionally, 8 mf of water was added each time a plate was processed.

After washing with water, the plate was desensitized using an oyster desensitizer in the post-treatment section.

(Fumaku fatifying agent) Dexto (PENON JE-66 manufactured by Nichikyo Kagaku Co., Ltd.)
...8 parts Carboxymethyl cellulose sodium salt ...0.45 parts Phosphoric acid ...0.2 parts Polyethylene oxide (average number of added moles of ethylene oxide 19) ...0. 5 parts Gum arabic 0.3 parts p-hydroxyethylbenshade 0.05 parts Water
... 90 parts of the first-stage unfattening liquid was circulated at a flow rate of In'/win while being spouted from a nozzle 8'' using No. 81.

Processing time is 10 seconds for printing plate [AI, 1 for printing plate [B]
The time was 5 seconds, and the liquid was replenished every 12 minutes.

After processing 28 plates of 600 sheets under the above conditions, 6
Even on the 00th printing plate, no stains or the like were observed during printing. In addition, the fukan fatifying agent was hardly fatigued.

FIG. 2 is a schematic side sectional view showing the automatic developing machine used in the implementation of this example. The IN position is similar to the one in Figure 1, but there is no skewer roller in the washing section, and the catch is roller 2 instead.
7 and a brush roller 29 are provided, and circulating washing water is supplied while rotating the refill roller 29 to perform washing processing. The developing solution is circulated within the developer tank 21, and 18 is a drain valve, and 19 is a waste tank.

Comparative Example 3 The water washing section was removed from the automatic developing machine used in Example 2, and desensitization treatment was performed immediately after passing through the development processing section. The conditions for development and desensitization were the same as in Example 1. Result 3
When processing the 28th plate of 00 sheets, scumming occurred in the non-image area of the printing plate, and the desensitizing agent was too tired to be used due to the developer brought in and had to be replaced. ,.

Comparative Example 4 The circulating water washing of the automatic developing machine used in Example 2 was stopped, and tap water was continuously supplied from a separately provided pipe to carry out running water washing. In other respects, when 500 plates were treated in the same manner as in Example 1, a good printing plate with no stains was obtained, but 600 plates were treated in the same manner as in Example 1.
More than 1,000 liters of water was consumed, and the same amount of waste water was generated, which required purification treatment.

Example 3 A surfactant aqueous solution 81 having a surgical composition was added to the post-processing section of the automatic processor shown in FIG.
250 plates each of plates [A] and [B] were processed.

(Surfactant aqueous solution) C(2-ethylhexyl)sul7osuccinate sodium...15 parts Sodium dihydrogen phosphate trihydrate...5.4 parts Citric acid -hydrate...・・1.2 parts water
・・・・・・100
Even in the 500th copy of the printing plate obtained, no staining was observed, and almost no fatigue of the surfactant aqueous solution was observed.

[Effect of the Invention 1] According to the present invention, it is possible to process negative and positive 18 plates in parallel using the same automatic developing machine, and to stably produce lithographic printing plates of good quality. The amount of water used was extremely small, resulting in many benefits such as saving water resources, reducing costs, and solving wastewater treatment problems. Furthermore, by the treatment of the present invention, a printing plate with good printability and high oil-insensitivity in non-image areas can be coated without impairing the oil-sensitivity in image areas. Furthermore, it was possible to improve the performance of the desensitizing agent and the rinsing liquid (aqueous surfactant solution, etc.) and the deterioration in processing ability during processing.

[Brief explanation of drawings]

1 and 2 are schematic side sectional views showing the structure of an automatic developing machine used in an embodiment of the present invention. Applicant Roku Konishi Photo Industry Co., Ltd. Procedural amendment dated October 2, 1985 1. Description of the case 1985 Patent Commissioner No. 175403 2. Name of the invention Processing method for photosensitive lithographic printing plates 3. Amendments made Relationship with the case Patent applicant address 1-1i-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 19
1 Konishiroku Photo Industry Co., Ltd., 1 Sakuracho, Hino City, Tokyo (Tel: 0425-83-152)
1) Patent Part 4, Date of Amendment Order Vol. 5, "Detailed Description of the Invention" column of the specification to be amended. 6. The [Detailed Description of the Invention] in the Statement of Contents of Amendment will be corrected as follows.

Claims (1)

[Claims] Using an automatic processor, negative photosensitive lithographic printing plates and/or
Alternatively, in a processing method in which a positive-working photosensitive lithographic printing plate is automatically transported and developed, the negative-working and/or positive-working photosensitive lithographic printing plate is developed with the same developing solution that is used repeatedly. A method for processing a photosensitive lithographic printing plate, characterized in that washing is performed using repeatedly used washing water.