JP2005275023A - Method for processing photosensitive planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a photosensitive planographic printing plate which has high sensitivity and also has small variation between sensitivity obtained through processing with a liquid developer at the start of development and sensitivity obtained through processing with a liquid developer after running processing. <P>SOLUTION: Disclosed is the method for processing the photosensitive planographic printing plate in which the photosensitive planographic printing plate having a photosensitive layer for a laser on a surface of an aluminum plate support is repeatedly developed with an automatic liquid developer, the method for processing the planographic printing plate being characterized in that development replenishment liquid and a development retarder containing solution are added to the liquid developer at the start of development and the mass of the development retarder containing solution is 1/200 to 1/10 time as large as that of the development replenishment liquid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for processing a photosensitive lithographic printing plate.

  The photosensitive lithographic printing plate is developed with an alkali developer after exposure to remove non-image areas, and then used for printing. Further, when developing a large number of plate materials, an automatic developing machine that repeatedly reuses a developer is usually used.

  However, the carbon dioxide gas in the air and the photosensitive layer in the non-image area are dissolved in the developer, and as a result, the activity of the developer is lowered. Therefore, by adding a developer replenisher with high development activity, the developer activity is increased. Has been maintained.

A technique of using a developer added with a development inhibitor such as an alkali-soluble resin at the start of development is disclosed. (For example, see Patent Document 1)
However, if an alkali-soluble resin is previously contained in a developer having a high pH, the performance may change over time due to hydrolysis of the resin. Also, if the composition of the developer at the start of development is different from the composition of the developer replenisher, separate management and storage is required, which is a burden on the work, and is processed with the sensitivity at the start of development and the developer after running. There is a great change in the sensitivity that can be obtained, and it is eagerly desired to solve these problems.
JP 2003-316023 A

  An object of the present invention is a method for processing a photosensitive lithographic printing plate with high sensitivity, sensitivity obtained by processing with a developer at the start of development and sensitivity change obtained by processing with a developer after running processing is small. It is to provide.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
In a processing method of a photosensitive lithographic printing plate in which a photosensitive lithographic printing plate provided with a laser photosensitive layer on the surface of an aluminum plate support is repeatedly developed with an automatic developer, a developer replenisher and a developer are added to the developer at the start of development. A processing method for a photosensitive lithographic printing plate, wherein an aqueous solution containing an inhibitor is added, and the mass of the aqueous solution containing a development inhibitor is 1/200 to 1/10 of the mass of the development replenisher.

  The processing method of the photosensitive lithographic printing plate according to the present invention is highly sensitive and has little change in sensitivity obtained by processing with a developing solution at the start of development and sensitivity obtained by processing with a developing solution after running processing. It has the effect.

Development inhibitor to be added to the development initiator The one having an effect of inhibiting development varies depending on the photosensitive layer constitution, and examples thereof include alkali-soluble resins such as carboxylic acid, acrylic resin having a sulfonic acid group, and acrylamide resin. The alkali-soluble resin lowers the pH of the developing solution and also loses the margin of the dissolving power of the developing solution.
When the photosensitive layer is a novolak resin-containing photosensitive layer like a thermal positive plate, a polyoxyethylene compound that coats the surface of the photosensitive layer and suppresses dissolution is also a dissolution inhibitor.

  In the present invention, the development replenisher and the development inhibitor-containing aqueous solution are added to the developer at the start of development, and the mass of the development inhibitor-containing aqueous solution is 1/200 to 1/10 of the mass of the development replenisher. It is characterized by that.

  The method of adding the development replenisher and the development inhibitor-containing aqueous solution to the developer at the start of development is, for example, a method of separately adding and mixing the development replenisher and the development inhibitor-containing aqueous solution, There are a method of adding a solution of a development inhibitor-containing aqueous solution and a method of adding a development replenisher and a development inhibitor-containing aqueous solution with an in-line mixer.

  Only the developer replenisher is added to the developer during the running process.

Silicic acid in developer (SiO ₂ concentration)
The SiO ₂ concentration is preferably 0.1% or less. If it exceeds 0.1% by mass, the silicate is solidified and sludge is easily generated when the developer is fatigued and its pH is lowered. If the silicic acid concentration is low, the pH buffering property will be low, so it is preferable to provide pH buffering property with carbonate.

Surfactant However, polyoxyethylene naphthyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene aryl ether, and polyoxyethylene naphthyl ether sulfonate are particularly preferable.

Alkaline agent The main component of the developer and replenisher used in the processing method of the present invention is at least one compound selected from silicic acid, phosphoric acid, carbonic acid, boric acid, phenols, saccharides, oximes, and fluorinated alcohols, or The alkali metal salt is preferably contained. These compounds are preferably coexisted with alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, and the pH is preferably in the range of 8.5 to less than 13.0. More preferably, the pH is 8.5-12.

  Among these, as weakly acidic substances such as phenols, saccharides, oximes and fluorinated alcohols, those having a dissociation index (pKa) of 10.0 to 13.2 are preferable. Such an acid is selected from those described in IONATION CONSTANTS OF ORGANIC ACIDS INAQUEOUS SOLUTION published by Pergamon Press, and specifically, salicylic acid (pKa = 13.0), 3-hydroxy-2-naphthoate, and the like. Acid (12.84), catechol (12.6), gallic acid (12.4), sulfosalicylic acid (11.7), 3,4-dihydroxysulfonic acid (12.2), 3,4 -Dihydroxybenzoic acid (11.94), 1,2,4-trihydroxybenzene (11.82), hydroquinone (11.56), pyrogallol (11.34), o-cresol (10. 33), resorsonol (11.27), p-cresol (10. 7), m-cresol (phenol having a phenolic hydroxyl group, such as the 10.09) and the like.

  As the saccharide, a non-reducing sugar that is stable even in an alkali is preferably used. Such non-reducing sugars are saccharides that do not have a free aldehyde group or ketone group and do not exhibit reducing properties, and are trehalose-type oligosaccharides in which reducing groups are bonded to each other, and glycosides in which a reducing group of saccharides and non-saccharides are bonded. These are classified into sugar alcohols reduced by hydrogenation of the body and saccharides, both of which are preferably used in the present invention.

  Trehalose type oligosaccharides include saccharose and trehalose. Examples of glycosides include alkyl glycosides, phenol glycosides, mustard oil glycosides, and the like. Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-exit, D, L-talit, durisit and allozulcit. Furthermore, maltitol obtained by hydrogenation of a disaccharide and a reduced form (reduced water candy) obtained by hydrogenation of an oligosaccharide are preferably used. Furthermore, 2-butanone oxime (12.45), acetoxime (12.42), 1.2-cycloheptanedione oxime (12.3), 2-hydroxybenzaldehyde oxime (12.10), dimethyl Oximes such as glyoxime (11.9), ethanediamide dioxime (11.37) and acetophenone oxime (11.35) such as 2,2,3,3-tetrafluoropropanol-1 (12) .74), trifluoroethanol (12.37), trichloroethanol (12.24), and the like. In addition, aldehydes such as pyridine-2-aldehyde (12.68) and pyridine-4-aldehyde (12.05), adenosine (12.56), inosine (12.5), guanine ( 12.3), nucleic acid-related substances such as cytosine (12.2), hypoxanthine (12.1), xanthine (11.9), diethylaminomethylsulfonic acid (12.32), 1-amino-3,3,3-trifluorobenzoic acid (12.29), isopropylidenedisulfonic acid (12.10), 1,1-ethylidene diphosphonic acid (11.54), 1,1 -1-hydroxyethylidene disulfonate (11.52), benzimidazole (12.86), thiobenzamide (12.8), picolinethioamide (12.55), barbi Include weak acid, such as Le acid (same 12.5). These acidic substances may be used alone or in combination of two or more. Among these acidic substances, preferred are silicic acid, phosphoric acid, carbonic acid, sulfosalicylic acid, salicylic acid and sugar alcohols and saccharose of non-reducing sugars, especially silicic acid, D-sorbitol, saccharose, and reduced water candy in an appropriate pH range. It is preferable that it has a buffering action and is inexpensive.

The proportion of these acidic substances in the developer is preferably from 0.1 to 30% by mass, and more preferably from 1 to 20% by mass. Below this range, a sufficient buffering effect cannot be obtained, and when the concentration is above this range, it is difficult to achieve high concentration, and the problem of increased costs arises. As the base to be combined with these acids, sodium hydroxide, ammonium, potassium and lithium are preferably used. These alkali agents are used alone or in combination of two or more. When the pH of the developer is 8.5 or less, the image portion of the printing plate obtained from the photosensitive lithographic printing plate that can be developed with such a developer is physically fragile, and the wear during printing is sufficient. Printing durability cannot be obtained. Further, the image portion is chemically weak, and an image of a portion wiped with an ink washing solvent or a plate cleaner is damaged during printing, and as a result, sufficient chemical resistance cannot be obtained. A developer having a high pH such that the pH exceeds 13.0 is strongly irritating when adhering to the skin or mucous membrane, and is not preferable because it requires sufficient care in handling.

Other examples include potassium silicate, sodium silicate, lithium silicate, ammonium silicate, potassium metasilicate, sodium metasilicate, lithium metasilicate, ammonium metasilicate, tripotassium phosphate, trisodium phosphate, trilithium phosphate, triammonium phosphate, phosphoric acid. Dipotassium, disodium phosphate, dilithium phosphate, diammonium phosphate, potassium carbonate, sodium carbonate, lithium carbonate, ammonium carbonate, potassium bicarbonate, sodium bicarbonate, lithium bicarbonate, ammonium bicarbonate, potassium borate, sodium borate, boric acid Lithium, ammonium borate and the like can be mentioned and may be added in the form of a preformed salt. Again, sodium hydroxide, ammonium, potassium and lithium can be added to the pH adjustment. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are also used in combination. Most preferred are potassium silicate and sodium silicate. The concentration of the silicate is preferably 1.0 to 4.0% by mass in terms of SiO ₂ concentration. Moreover, it is preferable if the molar ratio of SiO ₂ to alkali metal M (SiO ₂ / M) is in the range of 0.25-4.

  The developing solution referred to in the present invention is not only an unused solution used at the start of development, but also a replenishing solution is replenished to correct the activity of the solution that decreases due to the processing of the PS plate. Contains retained liquid (so-called running liquid). The replenisher therefore needs to have a higher activity (alkali concentration) than the developer, so the pH of the replenisher may exceed 13.0.

Surfactant In the developer and replenisher used in the present invention, various surfactants and organic solvents are added as necessary for the purpose of promoting the developability, dispersing the development residue and improving the ink affinity of the printing plate image area. Can be added. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferable examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene aryl ether, ester polyoxyethylene alkyl phenyl ethers, polyoxyethylene naphthyl ether, polyoxyethylene benzyl ether, polyoxyethylene polystyryl phenyl ether , Polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene aryl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid Partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters Tells, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, polyoxyethylene-polyoxypropylene block copolymers, polyoxyethylene of ethylenediamine Nonionic interfaces such as polyoxypropylene block copolymer adducts, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides Activators, fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid ester salts, linear alkyl benzene sulfonic acid salts, Branched alkylbenzene sulfonates, alkylnaphthalene sulfonates, polyoxyethylene aryl ether carboxylic acids, polyoxyethylene naphthyl ether sulfates, alkyl diphenyl ether sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl Sulfophenyl ether salts, polyoxyethylene aryl ether ether sulfate, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl ester Sulfuric acid ester salts, alkyl sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid ester salts, fatty acid monoglyceride sulfuric acid ester salts, poly Oxyethylene alkylphenyl ether sulfates, polyoxyethylene styrylphenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, styrene / anhydrous maleic Anionic surfactants such as partially saponified products of acid copolymers, partially saponified products of olefin / maleic anhydride copolymers, naphthalene sulfonate formalin condensates, alkylamine salts, tetrabutylammonium bromide, etc. Cationic surfactants such as quaternary ammonium salts, polyoxyethylene alkylamine salts, polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfurs Esters, amphoteric surfactants such as imidazolines.

  Among the surfactants listed above, those having polyoxyethylene can be read as polyoxyalkylenes such as polyoxymethylene, polyoxypropylene and polyoxybutylene, and these surfactants are also included. A more preferred surfactant is a fluorosurfactant containing a perfluoroalkyl group in the molecule. Such fluorosurfactants include perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, anionic types such as perfluoroalkyl phosphates, amphoteric types such as perfluoroalkyl betaines, and perfluoroalkyltrimethylammonium salts. Cationic and perfluoroalkylamine oxides, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl group and hydrophilic group-containing oligomers, perfluoroalkyl group and lipophilic group-containing oligomers, perfluoroalkyl groups, hydrophilic groups and lipophilic groups Nonionic types such as group-containing oligomers, perfluoroalkyl groups, and lipophilic group-containing urethanes can be mentioned. Said surfactant can be used individually or in combination of 2 or more types, and is added in 0.001-10 mass% in a developing solution, More preferably, it is added in 0.01-5 mass%.

Development Stabilizer For the developer and replenisher used in the present invention, various development stabilizers are preferably used. Preferred examples thereof include polyethylene glycol adducts of sugar alcohols described in JP-A-6-282079, tetraalkylammonium salts such as tetrabutylammonium hydroxide, phosphonium salts such as tetrabutylphosphonium bromide, and iodonium such as diphenyliodonium chloride. A salt is a preferred example.

  Further, anionic surfactants or amphoteric surfactants described in JP-A-50-51324, water-soluble cationic polymers described in JP-A-55-95946, and JP-A-56-142528 are described. There are water-soluble amphoteric polyelectrolytes that have been described. Furthermore, an organic boron compound to which an alkylene glycol is added as described in JP-A-59-84241, a polyoxyethylene-polyoxypropylene block polymerization type water-soluble surfactant as described in JP-A-60-111246, An alkylenediamine compound substituted with polyoxyethylene-polyoxypropylene disclosed in JP-A-60-129750, a polyethylene glycol having a weight average molecular weight of 300 or more described in JP-A-61-215554, and a cation described in JP-A-63-175858 And a fluorine-containing surfactant having a functional group, a water-soluble ethylene oxide addition compound obtained by adding 4 mol or more of ethylene oxide to an acid or alcohol disclosed in JP-A-2-39157, and a water-soluble polyalkylene compound.

Organic solvent If necessary, an organic solvent is added to the developer and developer replenisher. As such an organic solvent, those having a solubility in water of about 10% by mass or less are suitable, and are preferably selected from those having 5% by mass or less. For example, 1-phenylethanol, 2-phenylethanol, 3-phenyl-1-propanol, 4-phenyl-1-butanol, 4-phenyl-2-butanol, 2-phenyl-1-butanol, 2-phenoxyethanol, 2- Benzyloxyethanol, o-methoxybenzyl alcohol, m-methoxybenzyl alcohol, p-methoxybenzyl alcohol, benzyl alcohol, cyclohexanol, 2-methylcyclohexanol, 3-methylcyclohexanol and 4-methylcyclohexanol, N-phenylethanol Examples thereof include amines and N-phenyldiethanolamine. The content of the organic solvent is 0.1 to 5% by mass with respect to the total mass of the liquid used, but it is preferably substantially not contained, and particularly preferably not contained at all. Here, “substantially not contained” means 1% by mass or less.

Reducing agent A reducing agent is added to the developer and replenisher used in the present invention as necessary. This prevents stains on the printing plate, and is particularly effective when developing a negative photosensitive lithographic printing plate containing a photosensitive diazonium salt compound. Preferable organic reducing agents include phenol compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, and 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. More preferable inorganic reducing agents include sodium, potassium and ammonium salts of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, hydrogen phosphite, dihydrogen phosphite, thiosulfuric acid and dithionite. A salt etc. can be mentioned. Among these reducing agents, sulfites are particularly excellent in the antifouling effect. These reducing agents are preferably contained in the range of 0.05 to 5% by mass with respect to the developing solution at the time of use.

Organic carboxylic acid An organic carboxylic acid can be further added to the developer and replenisher used in the present invention, if necessary. Preferred organic carboxylic acids are aliphatic carboxylic acids and aromatic carboxylic acids having 6 to 20 carbon atoms. Specific examples of the aliphatic carboxylic acid include caproic acid, enanthylic acid, caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and particularly preferred are alkanoic acids having 8 to 12 carbon atoms. . Further, it may be an unsaturated fatty acid having a double bond in the carbon chain or a branched carbon chain. Aromatic carboxylic acids are compounds in which a carboxyl group is substituted on a benzene ring, naphthalene ring, anthracene ring, etc., specifically, o-chlorobenzoic acid, p-chlorobenzoic acid, o-hydroxybenzoic acid, p- Hydroxybenzoic acid, o-aminobenzoic acid, p-aminobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3, There are 5-dihydroxybenzoic acid, gallic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 1-naphthoic acid, 2-naphthoic acid and the like. Naphthoic acid is particularly effective. The aliphatic and aromatic carboxylic acids are preferably used as sodium salts, potassium salts or ammonium salts in order to enhance water solubility. The content of the organic carboxylic acid in the developer used in the present invention is not particularly limited, but if it is less than 0.1% by mass, the effect is not sufficient, and if it is 10% by mass or more, the effect cannot be further improved. In addition, dissolution may be hindered when other additives are used in combination. Therefore, the preferable addition amount is 0.1 to 10% by mass, more preferably 0.5 to 4% by mass with respect to the developing solution at the time of use.

Others In addition to the above, the following additives may be added to the developer and replenisher used in the present invention in order to enhance the development performance. For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, complexes such as [Co (NH3)] 6Cl3 described in JP-A-59-121336, JP-A-56-142258 Amphoteric polymer electrolytes such as vinylbenzyltrimethylammonium chloride and sodium acrylate copolymer described in JP-A No. 59-75255, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, JP-A-59 And organic boron compounds described in Japanese Patent No. -84241. The developer and replenisher used in the present invention may further contain a preservative, a colorant, a thickener, an antifoaming agent, a hard water softener, and the like, if necessary. Examples of the antifoaming agent include mineral oil, vegetable oil, alcohol, surfactant, silicone and the like described in JP-A-2-244143. Examples of the water softener include polyphosphoric acid and its sodium salt, potassium salt and ammonium salt, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminedisuccinic acid, methyliminodiacetic acid, β-alaninediacetic acid, triethylenetetraminehexaacetic acid, hydroxyethylethylenediaminetrimethyl. Aminopolycarboxylic acids such as acetic acid, nitrilotriacetic acid, 1,2-diaminocyclohexanetetraacetic acid and 1,3-diamino-2-propanoltetraacetic acid and their sodium, potassium and ammonium salts, aminotri (methylenephosphonic acid), Ethylenediaminetetra (methylenephosphonic acid), diethylenetriaminepenta (methylenephosphonic acid), triethylenetetraminehexa (methylenephosphonic acid) Hydroxyethyl ethylene diamine tri (methylene phosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid and their sodium salts, potassium salts and ammonium salts. The optimum value of such a hard water softening agent varies depending on its chelating power, the hardness of the hard water used and the amount of hard water. % By mass, more preferably in the range of 0.01 to 0.5% by mass. If the addition amount is less than this range, the intended purpose is not sufficiently achieved. If the addition amount is more than this range, adverse effects on the image area such as color loss will occur. The remaining component of the developer and replenisher is water. More preferably, the obtained developer has an electric conductivity of 3 to 100 mS and a surface tension of 200 to 800 μN / cm.

  JP 11-0665129, JP 11-0665126, JP 2000-206706, JP 2000-081711, JP 2002-091016, JP 2002-174907, JP 2002-182401, JP 2002-196506, JP 2002-196507, JP 2002-202616, JP 2002-229187, JP 2002-202615, JP 2002-251019, JP 2002-365813, JP 2003-029427, JP 2003-021908, JP 2003. Developed in 015318, JP2003-035960, JP2003-036993, JP2003-043701, JP2003-0437702, JP2003-057849, JP2003-066622, and the like. The material, treating agent such as the plate surface protective agent and the material, an automatic developing machine, can be suitably used for the processing method or the like.

Concentrated liquid It is advantageous in terms of transportation that the developer and replenisher used in the present invention are concentrated liquids having a lower water content than in use and are diluted with water during use. The degree of concentration in this case is appropriate so that each component does not separate or precipitate, but it is preferable to add a solubilizing agent if necessary. As such a solubilizer, toluenesulfonic acid, xylenesulfonic acid and alkali metal salts thereof described in JP-A-6-32081 are preferably used.

  The content of water in the concentrate can be further reduced to form a solid or paste. In this case, the developer may be once evaporated and then evaporated to dryness, but it is preferable that the concentrated state is obtained by mixing the materials without adding water when adding a plurality of materials or by adding a small amount of water. Is preferred. Further, this developer concentrate is disclosed in JP-A-51-61837, JP-A-2-109042, JP-A-2-109043, JP-A-3-39735, JP-A-5-142786, JP-A-6-266062, JP-A-7-2 Granules and tablets can be obtained by a conventionally well-known method described in US Pat. The material contained in the solid or paste developer concentrate can use the components used in the developer of ordinary photosensitive lithographic printing plates, but it does not return to its original state even if diluted with water. Is preferably not included. For example, since silicate is converted into stone when it becomes low in moisture, it becomes difficult to dissolve in water. Therefore, it is preferable to contain carbonate, phosphate, organic acid salt or the like instead of silicate.

  These developer concentrates or solid or paste concentrates may be divided into a plurality of parts having different material types, material mixing ratios, and the like. These concentrated developer concentrates are preferably used for development after dilution to a predetermined concentration with water before development. In addition, when this developer concentrate or concentrate is used as a developer replenisher, it is most preferable to dilute with water to a predetermined concentration and then add it to the developer in use. It is also possible to put it in a developing solution as it is without diluting to a predetermined concentration. When adding the developer concentrate to a developing solution in use at a concentration higher than a predetermined concentration or without diluting to a predetermined concentration, water is added directly to the developing solution in use at the same timing or at another timing. May be added.

Automatic developing machine The automatic developing machine used in the present invention is preferably provided with a mechanism for automatically replenishing a replenisher with a required amount in a developing bath, and preferably with a mechanism for discharging a developer exceeding a certain amount. Preferably, a mechanism for automatically replenishing a required amount of water to the developing bath is provided, and preferably a mechanism for detecting plate passing is provided. Preferably, a plate is detected based on detection of the plate passing. A mechanism for estimating the processing area of the replenishing liquid and / or the replenishment amount and / or replenishment timing of the replenishing liquid and / or water to be replenished is preferably controlled based on detection of the plate and / or estimation of the processing area. A mechanism for controlling the temperature of the developer, preferably a mechanism for detecting the pH and / or conductivity of the developer, and preferably for the developer. A mechanism is provided for controlling the replenishment amount and / or replenishment timing of replenisher and / or water to be replenished based on pH and / or conductivity. Moreover, when there exists a washing process after a image development process, the washing water after use can be used as a dilution water of the concentrate of a development concentrate and a development replenisher.

  The automatic processor used in the present invention may have a pretreatment unit that immerses the plate in the pretreatment liquid before the development step. The pretreatment unit is preferably provided with a mechanism for spraying the pretreatment liquid onto the plate surface, and preferably provided with a mechanism for controlling the temperature of the pretreatment liquid to an arbitrary temperature of 25 ° C to 55 ° C. Preferably, a mechanism for rubbing the plate surface with a roller-like brush is provided. Moreover, water etc. are used as this pretreatment liquid.

  The automatic processor used in the present invention preferably has a function of replenishing water in order to compensate for the evaporation of water in the developer. If the automatic processor has a water supply mechanism for diluting the concentrated developer, it may be used. A method of replenishing water determined per hour is the simplest and preferable method for replenishing water. However, the water replenishment amount may be corrected based on measured values from sensors such as pH of the developer and electric power. Further, the replenishment amount of water may be corrected using the temperature and / or humidity of the outside air, the temperature of the developer, the temperature and / or humidity of the air in the automatic developing machine, and the like.

  Also, the developer surface should be as small as possible in order to prevent the pH of the developer from decreasing due to the absorption of carbon dioxide in the air by the alkaline developer and the concentration of the developer due to evaporation of water in the developer. preferable. A high effect can be obtained by shielding the developer surface with a floating lid or the like. It is also an effective method to limit the contact between the air inside the self-machine and the outside air. It is preferable that the entrance / exit of the plate material of the automatic machine is as small as possible and has an automatic opening / closing mechanism that opens only when the plate material passes. Further, a method of removing carbon dioxide in the air in the self-machine is also effective, and a method of removing carbon dioxide by bringing an alkaline aqueous solution or alkaline developer waste liquid into contact with the air in the self-machine can be used effectively.

Post-processing A plate developed with a developer having such a composition is subjected to post-processing with a washing water, a rinsing solution containing a surfactant, a finisher mainly composed of gum arabic or starch derivatives, or a protective gum solution. . For the post-treatment of the PS plate of the present invention, these treatments can be used in various combinations. For example, a post-development → water wash → surfactant-containing rinse solution treatment or development → water wash → finisher solution treatment is a rinse solution. And less finisher fluid fatigue. Furthermore, a countercurrent multistage process using a rinse liquid or a finisher liquid is also a preferred embodiment.

  These post-processing are generally performed using an automatic developing machine including a developing unit and a post-processing unit. As the post-treatment liquid, a method of spraying from a spray nozzle or a method of immersing and conveying in a treatment tank filled with the treatment liquid is used. There is also known a method in which a small amount of washing water after development is supplied to the plate surface and washed, and the waste solution is reused as dilution water for the developer stock solution. In such automatic processing, processing can be performed while each replenisher is replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable treatment method in which treatment is performed with a substantially unused post-treatment liquid can be applied. The lithographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

Gum solution It is preferable to add an acid or a buffering agent to remove the alkali component of the developer. In addition, a hydrophilic polymer compound, a chelating agent, a lubricant, a preservative, a solubilizing agent, etc. may be added to the gum solution. it can. When the gum solution contains a hydrophilic polymer compound, it also has a function as a protective agent for preventing scratches and stains on the developed plate.

By adding a surfactant to the gum solution used in the present invention, the surface state of the coating layer is improved. Surfactants that can be used include anionic surfactants and / or nonionic surfactants. For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid salts, alkyl naphthalene sulfone. Acid salts, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, polyoxyethylene aryl ether sulfonates, polyoxyethylene naphthyl ether sulfonates, N-methyl-N-oleyl taurine sodium salts N-alkylsulfosuccinic acid monoamido disodium salts, petroleum sulfonates, nitrated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, Rualkyl nitrates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphate esters, polyoxyethylene alkyl ethers Phosphate ester salts, polyoxyethylene alkylphenyl ether phosphate ester salts, partially saponified products of styrene-maleic anhydride copolymer, partially saponified products of olefin-maleic anhydride copolymer, naphthalenesulfonate formalin condensates Etc. Among these, dialkyl sulfosuccinates, alkyl sulfate esters, and alkyl naphthalene sulfonates are particularly preferably used.
Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene aryl ethers, polyoxyethylene naphthyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxy Propylene alkyl ether, glycerin fatty acid partial ester, sorbitan fatty acid partial ester, pentaerythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene sorbitol fatty acid moiety Esters, polyethylene glycol fatty acid esters, polyglycerol fatty acid partial esters, polyoxyethylenated ester List oils, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, etc. It is done. Of these, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene-polyoxypropylene block polymers and the like are preferably used. Fluorine-based and silicon-based anions and nonionic surfactants can also be used. Two or more of these surfactants can be used in combination. For example, two or more different from each other can be used in combination. For example, a combination of two or more different anionic surfactants or a combination of an anionic surfactant and a nonionic surfactant is preferable. Although the usage-amount of the said surfactant does not need to specifically limit, Preferably it is 0.01-20 mass% of a post-processing liquid.

In the gum solution used in the present invention, polyhydric alcohols, alcohols and aliphatic hydrocarbons can be used as a wetting agent in addition to the above components as required.
Among the polyhydric alcohols, preferred specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, sorbitol and the like. Examples of the alcohol include propyl alcohol, butyl alcohol, and pen. Examples include alkyl alcohols such as tanol, hexanol, heptanol, and octanol, and alcohols having an aromatic ring such as pendyl alcohol, phenoxyethanol, and phenylaminoethyl alcohol. The content of these wetting agents is suitably 0.1 to 50% by mass, more preferably 0.5 to 3.0% by mass in the composition.

  Moreover, various hydrophilic polymers can be contained for the purpose of improving the film-forming property.

As such a hydrophilic polymer, any hydrophilic polymer that can be conventionally used in a gum solution can be preferably used. For example, gum arabic, fiber derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose etc.) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, polyacrylamide and copolymers thereof, vinyl methyl ether / maleic anhydride copolymer Examples thereof include a polymer, a vinyl acetate / maleic anhydride copolymer, and a styrene / maleic anhydride copolymer.
In general, the gum solution used in the present invention is more advantageously used in the acidic range of pH 3 to 6.

  In order to adjust the pH to 3 to 6, it is generally adjusted by adding a mineral acid, an organic acid, an inorganic salt, or the like in the post-treatment liquid. The addition amount is preferably 0.01 to 2% by mass. Examples of mineral acids include nitric acid, sulfuric acid, phosphoric acid, and metaphosphoric acid.

  Examples of the organic acid include citric acid, acetic acid, succinic acid, malonic acid, p-toluenesulfonic acid, tartaric acid, malic acid, lactic acid, levulinic acid, phytic acid, and organic phosphonic acid. Further, examples of the inorganic salt include magnesium nitrate, primary sodium phosphate, secondary sodium phosphate, nickel sulfate, sodium hexamethanoate, sodium tripolyphosphate, and the like. You may use together at least 1 sort (s) or 2 or more types, such as a mineral acid, an organic acid, or an inorganic salt.

  A preservative, an antifoaming agent, etc. can be added to the gum solution used in the present invention.

  For example, as a preservative, phenol or a derivative thereof, o-phenylphenol, p-chlorometacresol, hydroxybenzoic acid alkyl ester, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzoisothiazoline-3- ON, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, derivatives of pyridine, quinoline, guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, and the like. A preferable addition amount is an amount that exerts a stable effect on bacteria, molds, yeasts, etc., and varies depending on the type of bacteria, molds, yeasts, but 0.01% with respect to the plate surface protective agent at the time of use. The range of ˜4% by mass is preferable, and it is preferable to use two or more kinds of preservatives in combination so as to be effective against various molds and sterilization. As the antifoaming agent, a silicon antifoaming agent is preferable. Among them, emulsification dispersion type and solubilization can be used. Preferably, the range of 0.01 to 1.0% by mass with respect to the gum solution at the time of use is optimal.

Further, a chelate compound may be added. Preferred chelate compounds include, for example, ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, sodium salt thereof; ethylenediamine disuccinic acid, potassium salt thereof. Triethylenetetramine hexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof: nitrilotriacetic acid, sodium salt thereof; 1-hydroxyethane-1,1-diphosphone Acids, potassium salts, sodium salts; organic phosphonic acids or phosphonoalkanetricarboxylic acids such as aminotri (methylenephosphonic acid), potassium salts, sodium salts, etc. It can be mentioned. An organic amine salt is also effective in place of the sodium salt and potassium salt of the chelating agent. These chelating agents are selected so that they are stably present in the gum solution composition and do not impair the printability. The addition amount is suitably 0.001 to 1.0 mass% with respect to the gum solution at the time of use.
In addition to the above components, a sensitizer can be added as necessary. For example, hydrocarbons such as turpentine oil, xylene, toluene, low heptane, solvent naphtha, kerosene, mineral spirit, petroleum fraction having a boiling point of about 120 ° C to about 250 ° C, such as dibutyl phthalate, dihebutyl phthalate, di-n-octyl Phthalic acid diester agents such as phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate, such as dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, di ( 2-ethylhexyl) aliphatic dibasic acid esters such as sebacate and dioctyl sebacate, epoxidized triglycerides such as epoxidized soybean oil, such as tricresyl phosphate, trioctylfolate Feto, phosphoric acid esters such as tris chloroethyl phosphate, for example, freezing point, such as benzoic acid esters of benzyl benzoate and at 15 ℃ below boiling point at one atmosphere include 300 ° C. or more plasticizers.

In addition, caproic acid, enanthic acid, caprylic acid, helargonic acid, capric acid, undecyl acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoserine Saturated fatty acids such as acid, serotic acid, heptacosanoic acid, montanic acid, melicinic acid, lactelic acid, isovaleric acid, and acrylic acid, crotonic acid, isocrotonic acid, undecylenic acid, oleic acid, elaidic acid, celetic acid, nillic acid, buteticidin Examples also include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, propiolic acid, stearolic acid, sardine acid, talylic acid and licanoic acid. More preferably, it is a fatty acid that is liquid at 50 ° C., more preferably 5 to 25 carbon atoms, and most preferably 8 to 21 carbon atoms. These sensitizers can be used alone or in combination of two or more. A preferable range for the amount used is 0.01 to 10% by mass of the gum, and a more preferable range is 0.05 to 5% by mass.
The sensitizers as described above may be prepared by emulsifying and dispersing the gum as an oil phase, or may be solubilized with the help of a solubilizer.

In the present invention, the solid content concentration of the gum solution is preferably 5 to 30 g / l. The film thickness of the gum can be controlled by the conditions of the squeeze means of the automatic machine. In the present invention, the gum application amount is preferably 1 to 10 g / m ² . If the amount of gum application exceeds 10, the plate surface needs to be very hot in order to dry in a short time, which is disadvantageous in terms of cost and safety, and the effects of the present invention cannot be sufficiently obtained. When it is less than 1 g / m ² , uniform coating becomes difficult and stable processability cannot be obtained.
In the present invention, the time from the end of the application of the gum solution to the start of drying is preferably 3 seconds or less. More preferably, it is 2 seconds or less, and the shorter the time is, the better the ink deposition property is.
In the present invention, the drying time is preferably 1 to 5 seconds. When the drying time is 1 second or less, it is necessary to make the plate surface very hot in order to sufficiently dry the photosensitive lithographic printing plate, which is not preferable in terms of safety and cost.

  In the present invention, as a drying method, a known drying method such as a warm air heater or a far infrared heater can be used.

  In the drying step, the solvent in the gum solution needs to be dried. Therefore, it is necessary to ensure a sufficient drying temperature and heater capacity. The temperature required for drying varies depending on the components of the gum solution, but in the case of a gum solution in which the solvent is water, the drying temperature is preferably 55 ° C. or higher. The heater capacity is often more important than the drying temperature, and the capacity is preferably 2.6 kW or more in the case of the hot air drying method. The larger the capacity, the better, but 2.6-7 kW is preferable in terms of balance with cost.

Pre-development washing water In the present invention, the washing solution used in the washing step before development is usually water, but the following additives may be added as necessary.

  As the chelating agent, a compound that forms a chelate compound by coordination with a metal ion is used. Ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, ethylenediaminedisuccinic acid, its potassium salt, its sodium salt, triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt, diethylenetriaminepentaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof, nitriotriacetic acid, potassium salt thereof, sodium salt thereof, 1-hydroxyethane-1,1-diphosphonic acid, potassium salt thereof, sodium salt thereof, aminotri (methylenephosphone) Acid), potassium salt thereof, sodium salt thereof, phosphonoalkanetricarboxylic acid, ethylenediamine disuccinic acid, potassium salt thereof, sodium salt thereof and the like. Those chelating agents having an organic amine salt instead of the potassium salt and sodium salt are also effective.

  The addition amount of the chelating agent is suitably in the range of 0 to 3.0% by mass.

  As the surfactant, any of anionic, nonionic, cationic and amphoteric surfactants can be used, and anionic or nonionic surfactants are preferred. The preferred surfactant type varies depending on the composition of the overcoat layer and the photosensitive layer, and generally serves as a dissolution accelerator for the material of the overcoat layer and preferably has a low solubility for the components of the photosensitive layer.

  Examples of anionic surfactants include fatty acid salts, abichenates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropylsulfonates , Polyoxyethylene alkylsulfophenyl ether salts, sodium N-methyl-N-oleyl taurate, disodium N-alkylsulfosuccinic acid monoamide, petroleum sulfonates, sulfated castor oil, sulfated beef oil, fatty acid alkyl esters Sulfuric acid ester salts, alkyl sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid ester salts, fatty acid monoglyceride sulfuric acid ester salts, polyoxyethylene styrylpheny Ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkyl phenyl ether phosphate ester salt, partially saponified styrene-maleic anhydride copolymer, olefin-maleic anhydride copolymer And partially saponified products, naphthalenesulfonate formalin condensates and the like.

  Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid esters, sorbitan fatty acid partial esters , Pentaerythritol fatty acid partial ester, propylene glycol monofatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, iethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, polyoxyethylenated castor oil , Polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-hydroxyalkylamines Polyoxyethylene alkylamine, triethanolamine fatty acid esters, trialkylamine oxides and the like.

  A preferable addition amount of the surfactant is 0 to 10% by mass. Further, an antifoaming agent can be used in combination with the surfactant.

  Examples of preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazolin-3-one, benzotriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyrozine, Examples include quinoline and guanidine derivatives, diazine, triazole derivatives, oxazole and oxazine derivatives. Preferred examples include 1,2-benzisothiazolin-3-one, o-phenylphenol, hydroxybenzoic acid ethyl ester, chlorocresol and the like.

  In the cleaning method of the present invention, the cleaning solution used for cleaning before development is preferably used with the temperature adjusted, and the temperature is preferably in the range of 10 to 60 ° C. As a cleaning method, known processing liquid supply techniques such as spraying, dipping, and coating can be used, and processing promoting means such as a brush, a drawing roll, and a submerged shower in the dip processing can be used as appropriate.

  In the present invention, the development treatment may be performed immediately after completion of the pre-development washing step, or the development treatment may be performed after drying before the pre-development washing step. After the development step, known post-treatments such as washing with water, rinsing and gumming can be performed. The pre-development wash water used once or more is the post-development wash water, rinse solution, gum solution, developer solution.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the embodiment of this invention is not limited to these.

Example Example 1
EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited to these examples. In the examples, “parts” represents “parts by mass” unless otherwise specified.

(Binder synthesis)
(Synthesis of acrylic copolymer 1)
In a three-necked flask under a nitrogen stream, 30 parts of methacrylic acid, 50 parts of methyl methacrylate, 20 parts of ethyl methacrylate, 500 parts of isopropyl alcohol and 3 parts of α, α'-azobisisobutyronitrile are placed in a nitrogen stream. The mixture was reacted for 6 hours in an oil bath at 0 ° C. Then, after refluxing at the boiling point of isopropyl alcohol for 1 hour, 3 parts of triethylammonium chloride and 25 parts of glycidyl methacrylate were added and reacted for 3 hours to obtain an acrylic copolymer 1.

  The weight average molecular weight measured using GPC was about 35,000, and the glass transition temperature (Tg) measured using DSC (differential thermal analysis) was about 85 ° C.

(Production of support)
An aluminum plate (material 1050, tempered H16) having a thickness of 0.3 mm was immersed in a 5% aqueous sodium hydroxide solution maintained at 65 ° C., degreased for 1 minute, and then washed with water. This degreased aluminum plate was neutralized by dipping in a 10% aqueous hydrochloric acid solution maintained at 25 ° C. for 1 minute, and then washed with water. Next, the aluminum plate was subjected to electrolytic surface roughening with an alternating current for 60 seconds under conditions of 25 ° C. and a current density of 100 A / dm ^{2 in} a 0.3% by mass nitric acid aqueous solution, and then kept at 60 ° C. Desmutting treatment was performed for 10 seconds in a 5% aqueous sodium hydroxide solution. The surface-roughened aluminum plate subjected to desmut treatment was anodized in a 15% sulfuric acid solution at 25 ° C., a current density of 10 A / dm ² , and a voltage of 15 V for 1 minute, and further with hot water at 75 ° C. Hydrophilic treatment was performed to prepare a support.

(Preparation of lithographic printing plate materials)
On the support, a photopolymerizable photosensitive layer coating solution 1 having the following composition was applied with a wire bar so as to be 1.5 g / m ² when dried, and dried at 95 ° C. for 1.5 minutes. A coated sample was obtained.

(Photopolymerizable photosensitive layer coating solution 1)
Addition-polymerizable ethylenic double bond-containing monomer: M-3 25.0 parts Addition-polymerizable ethylenic double bond-containing monomer: NK ester 4G
(Polyethylene glycol dimethacrylate manufactured by Shin-Nakamura Chemical Co., Ltd.) 25.0 parts Polymerization initiator T-1 2.0 parts Polymerization initiator T-2 2.0 parts Polymerization initiator BR-22 1.0 part Polymerization initiator BR- 43 1.0 parts Spectral sensitizing dye D-1 1.5 parts Spectral sensitizing dye D-2 1.5 parts Acrylic copolymer 1 40.0 parts N-phenylglycine benzyl ester 4.0 parts Phthalocyanine pigment ( MHI454: manufactured by Mikuni Dye Co., Ltd.) 6.0 parts 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (Sumilyzer GS: manufactured by Sumitomo 3M) 0.5 parts Fluorosurfactant (F-178K; manufactured by Dainippon Ink & Co.) 0.5 parts Methyl ethyl ketone 80 parts Cyclohexanone 820 parts M-3 is as follows.

Nn-butyldiethanolamine (1 mol), 1,3-bis (1-isocyanato-1-methylethyl) benzene (2 mol), 2-hydroxypropylene-1-methacrylate-3-acrylate (2 mol) The reaction product of the above-mentioned photopolymerization photosensitive layer coating sample was coated with an oxygen barrier layer coating solution having the following composition with an applicator so as to be 1.8 g / m ² when dried, and at 75 ° C. for 1.5 minutes. It dried and the photosensitive lithographic printing plate sample which has an oxygen interruption | blocking layer on a photosensitive layer was produced.

(Oxygen barrier layer coating solution 1)
Polyvinyl alcohol (GL-05: Nippon Synthetic Chemical Co., Ltd.) 89 parts Water-soluble polyamide (P-70: Toray Industries, Inc.) 10 parts Surfactant (Surfinol 465: Nissin Chemical Industry Co., Ltd.) 0.5 parts Water 900 Part Developer Example Formula The developer / developer replenisher used in Example 1 is as follows.

Development inhibitor-containing aqueous solution 1
Acrylic copolymer 1 10.0 g / L
Polyoxyethylene naphthyl ether 30.0g / L
Ethylenediaminetetraacetic acid 0.5g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 11.2
Developer replenisher formulation 1
Potassium carbonate 2.5g / L
Potassium bicarbonate 5.0g / L
Surfactant A 30.0g / L
Ethylenediaminetetraacetic acid 0.5g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.4
The developer / developer replenisher used in Example 2 is as follows.

Development inhibitor-containing aqueous solution 2
Acrylic copolymer 1 7.0 g / L
Polyoxyethylene naphthyl ether 50.0g / L
Ethylenediaminetetraacetic acid 0.5g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 11.5
Developer replenisher formula 2
Potassium silicate aqueous solution (SiO ₂ : 26% by mass, K ₂ O: 13.5%) 40.0 g / L
Ethylenediaminetetraacetic acid 0.5g / L
Polyoxyethylene naphthyl ether 30.0g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.5
Comparative Example Development Starter Formula 3
Acrylic copolymer 1 10.0 g / L
Potassium carbonate 2.5g / L
Potassium bicarbonate 5.0g / L
Surfactant A 50.0 g / L
Ethylenediaminetetraacetic acid 0.5g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.0
Developer replenisher formula 3
Potassium carbonate 2.5g / L
Potassium bicarbonate 5.0g / L
Surfactant A 50.0 g / L
Ethylenediaminetetraacetic acid 0.5g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.4
Developer formula 4
Acrylic copolymer 1 10.0 g / L
Potassium silicate aqueous solution (SiO ₂ : 26% by mass, K ₂ O: 13.5%) 40.0 g / L
Ethylenediaminetetraacetic acid 0.5g / L
Surfactant A 40.0 g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.4
Developer replenisher formula 4
Potassium silicate aqueous solution (SiO ₂ : 26% by mass, K ₂ O: 13.5%) 40.0 g / L
Ethylenediaminetetraacetic acid 0.5g / L
Surfactant A 40.0 g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.7
Gum liquid (finisher liquid) formulation Plate surface protective agent Example 1 (1 L aqueous solution formulation)
White dextrin 5.0% by mass
Hydroxypropyl etherified starch 10.0% by mass
1st Ammon Phosphate 0.1% by mass
Sodium dilauryl succinate 0.15% by mass
Polyoxyethylene naphthyl ether 0.5% by mass
Sodium dodecylbenzenesulfonate 0.3% by mass
Ethylene glycol 1.0% by mass
Ethylenediaminetetraacetic acid disodium 0.05 mass%
Ethylparaben 0.05% by mass
Phosphonic acid compound A 0.5% by mass
The structural formulas of the compounds used in the above examples are given below.

About the photosensitive flat plate material 1 thus produced, 2400 dpi (dpi means the number of dots per 2.54 cm) using a CTP exposure apparatus (Tigercat: manufactured by ECRM) equipped with an FD-YAG laser light source. Image exposure (exposure pattern used 100% image area, 175 LPI, 50% square dots). Next, it is equipped with a pre-rinsing part for removing the oxygen blocking layer before development, a developing part filled with a developer having the following composition, a washing part for removing the developer adhering to the plate surface, and the above-mentioned gum solution for protecting the image area. Using a CTP automatic developing machine (PHW32-U: manufactured by Technigraph), a predetermined amount of a developing machine, a development replenisher, and a development inhibitor-containing aqueous solution were charged into the developer tank, and then the areas of the image area and the non-image area Development was carried out at 400 m ² so that the ratio was 1: 9. The replenishment of replenisher to approximately 100 ml / m ² was carried out.

Sensitivity In the 100% image area recorded on the plate surface of a lithographic printing plate, the lowest exposure energy amount at which no film reduction was observed was defined as the recording energy, and was used as an index of sensitivity. The smaller the recording energy, the higher the sensitivity.

  As can be seen from Table 1, the examples of the present invention are superior to the comparative examples.

Claims (1)

In a processing method of a photosensitive lithographic printing plate in which a photosensitive lithographic printing plate provided with a laser photosensitive layer on the surface of an aluminum plate support is repeatedly developed with an automatic developer, a developer replenisher and a developer are added to the developer at the start of development. A processing method for a photosensitive lithographic printing plate, wherein an aqueous solution containing an inhibitor is added, and the mass of the aqueous solution containing a development inhibitor is 1/200 to 1/10 of the mass of the development replenisher.