JPH0341454A - Processing method for negative photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To maintain development quality stably for a long period by composing a supplementary liquid developer of a solution which contains a surface active agent and an organic solvent and a solution which contains a reducing agents. CONSTITUTION:A negative type PS plate is developed by an automatic developing machine with a negative-only liquid developer which is used repeatedly by supplementing the supplementary liquid developer. A solution which contains the surface active agent and organic solvent and the solution which contains the reducing agent are supplemented as the supplementary liquid developer by supplementary amounts determined by the processing quantity of negative PS plates to be developed per unit time, the temperature of the outside air, and the type of the automatic developing machine.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a negative photosensitive lithographic printing plate (hereinafter referred to as "Negative 18
For more details, please refer to the processing method for the negative 18th plate using an automatic developing machine and replenishing the replenisher.
The present invention relates to a processing method of developing with a developer exclusively for S plate.

[Conventional technology]

BACKGROUND ART Conventionally, in the development process of a negative 18th plate using an automatic developing machine, it has been known to replenish the developer with a replenisher in order to stabilize the development quality in the case of long-term processing. As such a processing method, a replenisher containing at least one of the components of the developer at a concentration lower than that of the developer is added to the developer containing inorganic ions, and the electrical conductivity of the developer is increased. The method of measuring and replenishing was published in Japanese Patent Application Laid-open No. 6.
No. 0166950. Also, JP-A-60
No. 156063 describes a method of developing with a developer consisting of an aqueous solution containing an electrolyte, in which the alternating current impedance of the developer is measured and the same solution as in JP-A-60-166950 is replenished. ing.

In addition, JP-A-62-73271 describes a method in which two replenishers are used in a common developer for positive and negative types, and the composition of the replenisher is changed between negative and positive types. However, these replenishment methods replenish the negative PS plate with a replenisher of a fixed composition, so it may be necessary to change the situation of the developing operation, for example, when processing a large number of sheets in a short time or a small number of sheets in a long time, or There is a problem in that the consumption of components in the developer varies depending on the temperature of the outside air, and the finish of the development process varies.

[Purpose of the invention]

An object of the present invention is to provide a development replenishment method that can stably maintain development quality over a longer period of processing in a negative 13 plate processing method in which development is performed by replenishing a replenisher.

[Structure of the invention]

The above-mentioned object of the present invention is to provide a negative-type developer using an automatic developing machine and a developer exclusively for negatives that can be used repeatedly by replenishing the developer replenisher.
A developing method for developing a 3rd plate is distantly related to a negative 13th plate processing method characterized in that the developer replenisher comprises the following (A) and (B).

(A) Aqueous solution containing a surfactant and an organic solvent.

(B) Aqueous solution containing a reducing agent.

In the present invention, it is preferable to replenish the above (A) and (B) in an amount determined by the processing amount per unit time of the negative 13 plate to be developed, the outside temperature, and the type of automatic processor.

The present invention will be explained in detail below.

The negative 13th plate that is preferably processed by the processing method of the present invention has a photosensitive layer containing a diazo compound as a photosensitive component on the lithographic printing plate material, and the non-exposed areas are eluted by the development process and become non-image areas. It is.

Examples of diazo compounds include diazonium salts and/or diazo resins which are condensates of p-diazodiphenylamine and formaldehyde, phenol salts or fluorocapric acid salts of p-diazodiphenylamine described in Japanese Patent Publication No. 527364, and the like. Kosho 49-48001
2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid salt of a condensate of p-diazodiphenylamine and formaldehyde, p-diazo Examples include tetrafluoroborate and hexafluorophosphate of condensates of diphenylamine and formaldehyde.

The present invention can be preferably applied to a negative type 13 plate in which these are used 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, derivatives of polyvinyl alcohol, copolymers having alcoholic hydroxyl groups in side chains as described in JP-A-50-118802, and copolymers having alcoholic hydroxyl groups in the side chains as described in JP-A-55-155355. Examples include copolymers with phenolic hydroxyl groups in their side chains.

These resins include copolymers containing at least 50% by weight of structural units represented by the following general formula, (% formula%) (wherein R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrogen atom or a methyl group. ethyl group or chloromethyl group, n is an integer of 1 to 10) and aromatic hydroxyl group, and acrylic ester and/or methacrylic ester monomer unit. Included are polymeric compounds having 5 to 90 mol% of mer units and an acid value of 10 to 200.

Additives such as dyes, plasticizers, and components imparting printout performance can be added to the photosensitive layer of the negative 13 plate to which the developing method of the present invention is applied.

The negative developer in the present invention is preferably an aqueous solution containing a surfactant, an organic solvent, and a reducing agent.

As the surfactant, anionic, nonionic, cationic and amphoteric surfactants can be used, but anionic surfactants are preferred.

As anionic surfactants, higher alcohols (Ca~
C22) Sulfuric ester salts, such as sulium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, rTeepol-81J
(trade name, manufactured by Shell Chemical Co., Ltd.), sodium chloride alkylsal 7-A 1, etc.], aliphatic alcohol phosphate ester salts (e.g., sodium salt of cetyl alcohol phosphate, etc.), alkylaryl sulfonates (e.g., Sodium salt of dodecylbenzenesulfonic acid, sodium salt of isopropylnaphthalenesulfonic acid,
Synaphthalin disulfonic acid, rum salt, metanitrobenzene sulfonic acid salt, lithium salt, etc.), alkylamide sulfonate salts (for example, C+ 7813c)
ON(CH3)C1 (2sOJa), sulfonic acid salts of dibasic fatty acid esters (eg, sodium sulfosuccinate dioctyl ester, sodium sulfosuccinate dihexyl ester, etc.).

Among these, sulfonate salts are particularly preferably used.

Nonionic surfactants can be broadly classified into polyethylene glycol type and polyhydric alcohol type. Both can be used, but polyethylene glycol type nonionic surfactants are preferred from the viewpoint of development performance, and among them, ethylene glycol type nonionic surfactants are preferred. (CH2CH2O) and HLB value (HLB is Hydroph i 1e-Li
poph i 1eBa 1ance) is 5 or more (
More preferably, the nonionic surfactants 8 to 20) are more preferred.

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

Preferred examples of nonionic surfactants include the following general formula (1
) to [8].

(1) R-0-(C112CH20)n)][2] CH3RO(CH3COO)m (CH2CH20)nH[
4] (6) HO(C2H,0)a-(C3H60)b-
(C2H,0)cH(8) HO-(CH2CH20
)nH [1] to [8] In formulas, R is a hydrogen atom or 1
represents a valent organic group. The organic group is, for example, a linear or branched alkyl group having 1 to 30 carbon atoms that may have a substituent (for example, an aryl group (phenyl, etc.)), an alkyl moiety, or the above alkyl group. Examples thereof include an alkylcarbonyl group, a phenyl group which may have a substituent (for example, a hydroxyl group, the above-mentioned alkyl group, etc.). alb, c, , m, n, x and y are each l −4
Represents an integer of 0.

one Specific examples of nonionic surfactants are shown below.

Polyethylene glycol, polyoxyethylene lauryl ether, polyoxyethylene nonyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether,
Polyoxyethylene behenyl ether, polyoxyethylene polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene behenyl ether, holoxyethylene nonylphenyl ether, holoxyethylene octylphenyl ether, polyoxyethylene stearyl amine, polyoxyethylene oleyl amine, poly Oxyethylene stearamide, polyoxyethylene oleic acid amide, polyoxyethylene human oil, polyoxyethylene abiethyl ether, polyoxyethylene lanolin ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene glyceryl Monooleate, polyoxyethylene glycel monostearate, polyoxyethylene propylene glycol monostearate, oxyethylene oxypropylene block polymer, disketonated 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 is 300 to 1.0
The range of 000 is preferred, and the range of 500 to 5000 is particularly preferred.

Cationic surfactants are broadly classified into amine type and quaternary ammonium salt type, and any of these can be used.

Examples of amine types include polyoxyethylene alkylamine, N-alkylpropylene amine, N-alkyl polyethylene polyamine ethylene polyamine dimethyl biguanide, long chain amine oxide, alkylimidacilline, 1-hydroxyethyl-2-alkylimidacilline, (2)-Acetylaminoethyl-2-alkylimidacillin, 2-alkyl-4-methyl-4-hydroxymethyloxazoline, and the like.

Examples of quaternary ammonium salts include long-chain quaternary 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 1 fatty acid triethanolamine, fatty acid cyphthylaminoethanol, cetyloxymethylpyridinium salt, p -Inoctylphenoxyethoxyethyldimethylbenzylammonium salt, etc. (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, and stearyl are preferably used. ) Among these, water-soluble quaternary ammonium salt type cationic surfactants are particularly effective, and among them, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, ethylene oxide-added ammonium salts, etc. are preferable. Further, a polymer having a cationic component as a repeating unit is also a cationic surfactant in a broad sense, and is used as the cationic surfactant of the present invention. In particular, a polymer containing a quaternary ammonium salt obtained by copolymerizing with a lipophilic monomer 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.

2 As the amphoteric surfactant, for example, a compound such as sodium N-methyl-N pentadecylaminoacetate can be used.

These surfactants are preferably contained in an amount of 0.5 to 0% by weight.

As an organic solvent, the solubility in filtered water at 20°C is 1.
Preferably, 0% by weight or less, such as carboxylic acid esters such as ethyl acetate, propyl acetate, butyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate; ethyl butyl ketone, methyl isobutyl Ketones, such as cyclohexanone: ethylene glycol monobutyl ether,
Alcohols such as ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol; Alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, ethylene dichloride, There are halogenated hydrocarbons such as monochlorobenzene. One or more of these organic solvents may be used.

The content of the organic solvent in the developer is preferably 0.05 to IO% by weight.

As the reducing agent, a water-soluble or alkali-soluble organic or inorganic reducing agent can be used.

Examples of organic reducing agents include hydroquinone,
Examples of inorganic reducing agents include phenolic compounds such as chlorine, methoxyquinone, and amine compounds such as phenylenediamine and phenylhydrazine. Examples of inorganic reducing agents include sodium sulfite,
Sulfites such as potassium sulfite, ammonium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium dihydrogen phosphite,
Examples include phosphates such as potassium bisulfite, hydrazine, sodium thiosulfate, and sodium dithionite, but sulfites are particularly effective reducing agents. These reducing agents are contained in an amount of 0.1-10% by weight, more preferably 0.5-5% by weight.

In addition to the above, the developer may contain an alkaline agent, an organic carboxylic acid, and other additives.

Examples of alkaline agents include alkali silicates (potassium silicate, sodium silicate, etc.), potassium hydroxide, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic potassium phosphate and Inorganic alkaline agents such as potassium diphosphate, tertiary ammonium phosphate, ammonium diphosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc., mono-, di- or triethanolamine and tetrahydroxide. Organic alkaline agents such as alkyl and organic ammonium silicates can be used. The content of the alkaline agent in the developer is preferably in the range of 0.05 to 20% by weight, more preferably in the range of 0.1 to 10% by weight.

The organic carboxylic acids include aliphatic carboxylic acids having 6 to 20 carbon atoms and aromatic carboxylic acids 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, valmitic 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 acids may be used as sodium or potassium salts or ammonium salts.

Specific compounds of aromatic carboxylic acids include benzoic acid, 0-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, p-te
r t-butylbenzoic acid, 0-aminobenzoic acid, p-
Ami-7benzoic acid, 2,4-dihydroxybenzoic acid, 2.
5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, gallic acid, ■-hydroxy-2-su6
-7toic acid, 3-hydroxy-2-su7toic acid, 2-hydroxy-1-naphthoic acid, -naphthoic acid, 2-naphthoic acid, etc.

The above aromatic carboxylic acid may be used as a sodium or potassium salt or an ammonium salt.

There is no particular restriction on the content of aliphatic carboxylic acid and aromatic carboxylic acid, but if it is lower than 0.1% by weight, the effect will not be sufficient, and if it exceeds 30% by weight, no further improvement in the effect can be measured. Or, when used in combination with other additives, dissolution may be hindered. Therefore, the amount added is preferably 0.1 to 10% by weight, more preferably 0.5 to 4% by weight.

The pH of the developer is preferably in the range of 1O10 to 13.5.

Further, the following additives can be added to the developer used in the present invention in order to improve development performance. For example, NaCQ, KCo, described in JP-A No. 58-75152,
, neutral salts such as KBr, chelating agents such as EDTA and NTA described in JP-A-59-190952, JP-A-59-1909
(Co(NH3))6CL described in -121336 publication
Complexes such as JP-A-56-1425211, amphoteric polymer electrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate, and inorganic compounds such as lithium chloride described in JP-A-58-59444. Lithium compounds, organic lithium compounds such as lithium benzoate described in Japanese Patent Publication No. 50-34442, organometallic surfactants containing Si, Ti, etc. described in Japanese Patent Application Publication No. 59-75255, Japanese Patent Publication No. 59-75255
Examples include organic boron compounds described in Publication No. 9-84241.

Next, the developer replenisher according to the present invention will be explained.

The developer replenisher of the present invention consists of an aqueous solution containing a surfactant and an organic solvent (replenisher (A)) and an aqueous solution containing a reducing agent (replenisher (B)), and water is also used for dilution. It may be a configuration.

Among the two-part developer replenisher of the present invention, replenisher (A)
Examples of the surfactant and organic solvent contained in the replenisher (B) include the surfactant and organic solvent in the developer described above, and as the reducing agent contained in the replenisher (B), the reducing agent in the developer described above can be used. I can do it.

The concentration of the surfactant and organic solvent in the replenisher (A) and the concentration of the reducing agent in the replenisher (B) are the same as that of the replenisher (A) and the replenisher (B) (and if dilution water is used). dilution water)
It is preferable that the composition of the liquid to be mixed and replenished is equal to or higher than the respective concentrations in the developer.

The replenisher (A) and the replenisher (B) can contain the additives in the developer described above.

In that case, it may be included as appropriate in consideration of solubility, stability, etc. Note that the additives contained in the developer are preferably also added to the replenisher in order to maintain the performance of the developer.

In the present invention, the replenisher (A) and the replenisher (B) can be replenished at a replenishment amount determined by the processing amount per unit time of the positive PS plate to be developed, the outside temperature, and the type of automatic processor. preferable.

For example, the higher the outside air temperature surrounding the developer, the higher the replenisher (
For example, the amount of replenishment of only B) is increased, and the proportion of replenisher (A) is decreased as the throughput decreases.

9 Such qualitative relationships are shown in Table 1 below.

Table 1 (Note) (1) ■ is a type in which developer is supplied to the PS plate by shower.

■ is a type in which the PS plate is immersed in a developer.

(2) / indicates an increase, \ indicates a decrease, and → indicates no increase or decrease.

As described above, the present invention employs the above-mentioned two-liquid structure for the developer replenisher, so that appropriate replenishment is possible according to the fluctuation factors for replenishment, and it is possible to maintain good development quality during long-term processing. This is what I did.

0 〔Example〕 The present invention will be explained below with reference to Examples.

Example 1 The following developer (A) 2412 was put into the developer tank 4 of the automatic processor shown in FIG. 1, and the following developer replenisher (A1) and (
B1) was prepared.

Developer (A) Ethylene glycol monophenyl ether 20 parts 3-methyl-3methoxybutanol 75 parts Sodium sulfite 3 parts Sodium butylnaphthalene sulfonate 5 parts Water 500 parts Developer replenisher (A1) Ethylene glycol mono 20 parts by weight of phenyl ether 75 parts by weight of 3-methyl-3methoxybutanol = 22 parts by weight of sodium butylnaphthalene sulfonate 5 parts by weight of water 300 parts by weight of developer replenisher (Bl) Sodium sulfite 5 parts by weight of water
200 parts by weight, then thickness 0.
A 24 mm JIS-1050 aluminum plate was immersed in a 20% sodium phosphate aqueous solution to degrease it, electrochemically roughened in a dilute hydrochloric acid solution, thoroughly washed, and then anodized in a dilute sulfuric acid solution.1. An oxide film of 5 g/m2 was formed on the surface of the aluminum plate. The aluminum plate treated in this way was roughly immersed in an aqueous solution of sodium metasilicate for pore sealing, washed with water, dried, and then coated with a photosensitive solution having the following composition to a dry weight of 2.0 g/m2. It was then dried to obtain a negative 13th plate. The plate size was LOO3mm x 800mm.

Photosensitive liquid composition Hexafluorophosphate of a condensate of p-diazodiphenylamine and paraformaldehyde
1 part by weight N-(4-hydroxyphenylmethacrylamide copolymer (described in Example 1 of Japanese Patent Publication No. 57-43890)) 10 parts by weight Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Industry Co., Ltd.) , dye) 0.2 parts by weight ethylene glycol monomethyl ether 100 parts by weight A large number of negative PS plates thus obtained were prepared, and a transparent negative film and a step tablet for sensitivity measurement (manufactured by Eastman Kodasoku Co., No. 2, Concentration difference 0.1
21 levels of gray scale) in close contact with each other, 2kW
Exposure was carried out for 30 seconds from a distance of 70 cm under the condition of 8.0 mW/cm 2 using a metal halide lamp (Idol Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) as a light source.

Fifty sheets of I-Ga type PS plates thus obtained were processed at 27°CCl2O seconds using a prepared automatic developing machine.

During the treatment, plates were inserted at 10 minute intervals. The room temperature at this time was 25
It was °C. Also, while processing, 13th edition l m2
Add 20ml of replenisher (A1) after each development. Replenishment 3 Added 30mQ (2) of replenisher (B1). Due to air fatigue, 50mQ of replenisher (B1) was added every 30 minutes.50
After processing the sheets, the first step tablet and the last 50th step tablet were compared, and both had exactly the same development quality.

In FIG. 1, ■ is a developing section that performs development processing, and 2 is a developing section that performs development processing.
3 is a water washing section, 3 is a rinse/gum section for processing with a rinsing liquid or desensitizing liquid, 4 is a developer tank, 5 to 7 are processing liquid supply nozzles, 8 to 10 are pumps, and S is a PS plate or its This is the transport route.

Example 2 The same negative PS plate, developer, developer replenisher, and automatic processor as in Example 1 were prepared.

The treatment was carried out at 27°CCl2O seconds at 5 minute intervals for 100 sheets.

During the processing, 20 m (2) of replenisher (A1) and 39 m (2) of replenisher (B1) were added for every 1 m2 of 48 plates developed.

Refill fluid (Bl) every 30 minutes due to air fatigue]
000m12 was added. After processing 100 sheets, the first step tablet and the last 100th step tablet were compared, and both had exactly the same development quality.

5 4 Example 3 As a result of conducting the same experiment as in Example 1 except that the following developer (B) and developer replenisher (A2) and (B2) were used, the first 1st sheet and the last 50th sheet were No difference was observed in the development quality of the step tablets.

Developer (B) Benzyl alcohol 25ml 1 part Triethanolamine 8 parts by weight Sodium sulfite
3 parts by weight Sodium butylnaphthalene sulfonate IO 500 parts by weight Developing replenisher (A2) Benzyl alcohol 25 parts by weight Triethanolamine 8 parts by weight Butylnaphthalene sulfonate 10 parts by weight Water 300 parts by weight B2) Sodium sulfite 5 parts by weight = 26 Water - 200 parts by weight Example 4 Using the automatic developing machine shown in FIG. 2, using the same developer, developer replenisher, and negative PS plate as in Example 1, Example The treatment was carried out in the same manner as in 1. Also, while processing, 18 plate 1m
For every two developments, 25 mI2 of replenisher (A2) and 30 mα of replenisher (B2) were added. 3 more due to air fatigue
50 mff of replenisher (B2) was added every 0 minutes. After processing 50 sheets, the first step tablet and the last 50th step tablet were compared, and no difference was found in the development quality.

In addition, in FIG. 2, 11 is a developing section that performs a developing process;
12 is a water washing section, I3 is a rinse/gum section for processing with a rinsing liquid or desensitizing liquid, 14 is a developing tank, 15.16.
17 is a processing liquid supply nozzle, 18.19.20 is a pump,
S is the PS plate or its transport route. In the same figure, *l and *
The first class is connected by piping.

Comparative Example 1 The same experiment as in Example 1 was conducted except that the following developer replenisher (C) was used, and during processing, 50 mff of replenisher (C) was added for every 1 m2 of PS plate developed. . Due to air fatigue, 3Qmff of replenisher (C) was added every 30 minutes. After processing 50 sheets, the first 1 sheet and the last 50 sheets
When comparing the second step tablet, the solid sensitivity was almost the same, but the clear sensitivity was significantly different.

Developer replenisher (C) Benzyl alcohol 25 parts by weight Triethanolamine 8 parts by weight Sodium sulfite
5 parts by weight Sodium butylnaphthalene sulfonate 10 parts by weight Water 500 parts by weight Comparative Example 2 The same treatment as in Example 4 was carried out using the developer replenisher (C). During the processing, 60 mff of replenisher (C) was added for every 1 m2 of PS plate developed. Due to air fatigue, 5Qmff of replenisher (C) was added every 30 minutes. After processing 50 sheets, we compared the first step tablet with the last 50th step tablet, and found that the solid sensitivity was almost the same, but the clear sensitivity was significantly different.

〔Effect of the invention〕

According to the present invention, it is possible to stably maintain development quality over a longer period of time in a processing method in which a negative PS plate is developed with a developer exclusively for negative PS plates, which is repeatedly used by replenishing the replenisher over a long period of time. I can do it.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views showing an example of the apparatus used in the example. l511...Developing section 2.12...Water washing section 3.13...Rinse/gum section

Claims (2)

[Claims] (1) In a development processing method in which a negative photosensitive lithographic printing plate is developed using an automatic developing machine with a developer exclusively for negatives that is repeatedly used by replenishing a developer replenisher, the developer replenisher is one of the following (A) and A method for processing a negative photosensitive lithographic printing plate, characterized by comprising the two liquids (B). (A) Aqueous solution containing a surfactant and an organic solvent. (B) Aqueous solution containing a reducing agent. (2) The above (A) and (B) are replenished at a replenishment amount determined by the processing amount per unit time of the negative photosensitive lithographic printing plate to be developed, the outside temperature, and the type of automatic processor. The processing method according to claim (1).