JP2009142993A - Treatment method of photosensitive lithographic printing plate material and plate surface protectant of photosensitive lithographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method of a photosensitive lithographic printing plate material which can prevent a microdotted stain (stop stain) from being generated on a nonimage part after stopping a printing machine for a while in order to perform a registering operation during printing, and to provide a plate surface protectant of the photosensitive lithographic printing material. <P>SOLUTION: This treatment method of the photosensitive lithographic printing plate material is to treat the photosensitive lithographic printing plate material with a photosensitive layer made up of a photosensitive resin composition formed on an aluminum support with the help of the plate surface protectant. This plate surface protectant contains a surfactant of such a construction as shown by formula I. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for treating a photosensitive lithographic printing plate material and a plate surface protective agent for the photosensitive lithographic printing plate material.

  Conventionally, the lithographic printing method is a printing method that utilizes the fact that water and oil do not essentially mix, and the printing plate surface accepts water and repels oil-based ink, and repels water and oil-based ink. Is formed, and water and oil-based ink are supplied from a printing machine, and printing is performed by transferring only the oil-based ink received in the image portion to paper. The printing machine generally uses an offset printing method in which the oil-based ink received in the image portion of the printing plate surface is once transferred to a rubber blanket and then transferred to paper.

  Conventionally, the support used for the photosensitive lithographic printing plate material has been required to have excellent hydrophilicity, water retention, and adhesion to the photosensitive layer from the viewpoint of printability. An aluminum plate that has been subjected to a surface roughening process called graining is used. As the roughening treatment, mechanical surface roughening methods such as ball polishing, brush polishing, blast polishing, buff polishing, honing polishing, etc., and electrolysis of the support surface by alternating current or direct current in an acidic electrolyte such as hydrochloric acid and nitric acid. An electrochemical surface roughening method for processing is known. The aluminum plate grained by such a method is relatively soft and easy to wear as it is, and then anodized to form an oxide film. The surface of the aluminum plate treated in this way is hard and has excellent wear resistance.

  When the exposed photosensitive lithographic printing plate material is developed with an alkaline aqueous solution, the exposed or unexposed portion of the photosensitive layer is removed, and the surface of the support is exposed. Since the surface of the aluminum support is hydrophilic, the portion where the surface of the support is exposed by development (non-image portion) receives water and repels the oil-based ink. On the other hand, the portion where the photosensitive layer has not been removed by development (image portion) is oleophilic and therefore repels water and accepts the oil-based ink.

  Generally, the photosensitive lithographic printing plate material has a higher sensitivity, so that the time required for exposure is shortened and the work can be performed quickly. When printing such a photosensitive lithographic printing plate material, after stopping the printing machine for a while due to registration or breaks during printing work, fine dot-like stains that occur in the non-image area when printing resumes occur. In some cases (hereinafter referred to as “stop stain”), in order to prevent this stain, a method of maintaining the hydrophilicity of the plate surface of the non-image area has been desired.

  Conventionally, alkali metal silicate aqueous solutions have been widely used for the development of photosensitive lithographic printing plate materials, and the hydrophilicity of the support surface is increased by the reaction of aluminum on the support surface with silicic acid in the developer. However, with this method alone, the hydrophilicity was not sufficiently maintained, and stop dirt could not be completely suppressed.

  Further, when the photosensitive lithographic printing plate material is made into a lithographic printing plate, a plate surface protective agent is applied in the final step. The purpose of applying the plate surface protection agent is not only to protect the hydrophilicity of the non-image area, but also to modify the image area such as writing or erasing, storage for the period until printing after plate making, or storage until reuse, for printing machines This is to prevent contamination caused by adhesion of fingerprints, oils and fats, dust, etc. during attachment and handling, and to protect against the occurrence of scratches, and to further suppress the occurrence of oxidized stains. Conventionally, as a plate surface protecting agent for a photosensitive lithographic printing plate material, gum arabic, cellulose gum or an aqueous solution of a water-soluble polymer having a carboxyl group in the molecule is generally used. In addition, it contains a plate surface protective agent containing phosphoric acid-modified starch (see Patent Document 1), a plate surface protective agent containing carboxyalkylated starch (see Patent Document 2), and a specific polyoxyethylene group-containing activator. A plate surface protective material (see Patent Document 3) is disclosed, and many plate surface protective agents containing a water-soluble polymer have been proposed. However, this method alone does not sufficiently maintain the hydrophilicity of the non-image area plate surface, and the stop stain cannot be completely suppressed.

  In addition, in a photopolymerizable photosensitive lithographic printing plate material of the type that forms a latent image by a free radical reaction by a combination of a photofree radical generator and an ethylenically unsaturated compound, an image is exposed to light using an alkaline aqueous solution. When a photopolymerizable photosensitive lithographic printing plate material having a polymerizable layer is developed, an excellent lithographic printing plate with high sensitivity can be obtained. However, when the development processing of a large number of photopolymerizable photosensitive lithographic printing plate materials is repeated by a method of replenishing the developer replenisher using an automatic processor and elution in the developer of the automatic processor. It has been found that a photopolymerizable layer is deposited. Furthermore, the photopolymerizable photosensitive lithographic printing plate material of the type that forms a latent image by the above free radical reaction generally has an excellent sensitivity, but has a drawback that the free radical reaction is inhibited by oxygen. Therefore, it is effective to provide some kind of oxygen barrier layer on the photosensitive layer, and it is known that such an oxygen barrier layer is mainly composed of polyvinyl alcohol as a main component. However, the same processing is performed by repeatedly using a photopolymerizable photosensitive lithographic printing plate having an oxygen blocking layer mainly composed of polyvinyl alcohol on the photosensitive layer by replenishing a developing replenisher using an automatic processor. It has also been found that when it is repeated, an agar-like gel precipitates in the developer of the automatic processor.

The plate material obtained by such an unstable development process promotes the occurrence of the above-mentioned stop dirt, and has been a problem in use.
Japanese Unexamined Patent Publication No. Sho 62-11663 Japanese Patent Laid-Open No. 62-7595 JP 11-265704 A

  The present invention has been made in view of the above problems, and an object of the present invention is to form a fine dot-like shape that occurs in a non-image portion when printing is resumed after the printing press is stopped for a while due to registration or break during printing. It is an object of the present invention to provide a method for treating a photosensitive lithographic printing plate material and a plate surface protecting agent for the photosensitive lithographic printing plate material that can prevent the occurrence of dirt (stop dirt).

  The above object of the present invention can be achieved by the following constitution.

  1. A photosensitive lithographic printing plate material in which a photosensitive layer composed of a photosensitive resin composition is formed on an aluminum support is exposed, developed with a developer, and then processed with a plate surface protective agent. In the processing method of printing plate material, The plate surface protecting agent contains surfactant of the structure shown by the following general formula I, The processing method of photosensitive lithographic printing plate material characterized by the above-mentioned.

(In the formula, R ₁ and R ₂ each independently represents an alkyl group having 8 to 20 carbon atoms, and X represents a single bond or an organic linking group having 1 to 20 carbon atoms.)
2. 2. The method for treating a photosensitive lithographic printing plate material according to 1, wherein the surfactant having the structure represented by the general formula I is the following compound 1.

  3. 3. The method for processing a photosensitive lithographic printing plate material according to 1 or 2, wherein the plate surface protective agent further contains a surfactant containing an aromatic hydrophobic group and a polyalkylene group.

  4). Photosensitive lithographic printing plate used for treatment with a plate surface protective agent after exposure and development treatment with a developer of a photosensitive lithographic printing plate material having a photosensitive layer composed of a photosensitive resin composition on an aluminum support A plate surface protective agent for a photosensitive lithographic printing plate material, wherein the plate surface protective agent contains a surfactant having a structure represented by the following general formula I:

(In the formula, R ₁ and R ₂ each independently represents an alkyl group having 8 to 20 carbon atoms, and X represents a single bond or an organic linking group having 1 to 20 carbon atoms.)
5). 5. The plate surface protective agent for a photosensitive lithographic printing plate material according to 4, wherein the surfactant having the structure represented by the general formula I is the following compound 1.

  6). 6. The plate surface protective agent for a photosensitive lithographic printing plate material according to 4 or 5, wherein the plate surface protective agent further contains a surfactant containing an aromatic hydrophobic group and a polyalkylene group.

  According to the present invention, photosensitive lithographic printing that can prevent the occurrence of fine spot-like stains (stop stains) that occur in non-image portions when printing is resumed after the printing press has been stopped for a while due to registration or breaks during printing. A plate material processing method and a plate surface protecting agent for a photosensitive lithographic printing plate material can be provided.

  Hereinafter, although the best mode for carrying out the present invention will be described, the present invention is not limited to these.

  In the processing method of the photosensitive lithographic printing plate material of the present invention, a photosensitive lithographic printing plate material in which a photosensitive layer made of a photosensitive resin composition is formed on an aluminum support is developed with a developer after exposure. Then, in the method of processing a photosensitive lithographic printing plate material, which is then processed using a plate surface protective agent, the plate surface protective agent contains a surfactant having a structure represented by the general formula I.

  In addition, a photosensitive lithographic printing plate material having a photosensitive layer composed of a photosensitive resin composition on an aluminum support, a photosensitive lithographic plate used for processing with a plate surface protective agent after exposure and development processing with a developer. The plate surface protective agent for a printing plate material is characterized in that the plate surface protective agent contains a surfactant having a structure represented by the general formula I.

  The present invention will be described in detail below.

  In the processing method for the photosensitive lithographic printing plate material of the present invention, the photosensitive lithographic printing plate material is developed with a developer after exposure, and then processed with the plate surface protective agent of the present invention.

<Developer>
First, the developer and replenisher used in the present invention will be described.

(Alkaline agent)
The main component of the developer and replenisher used in the processing method of the present invention may contain at least one compound selected from silicic acid, phosphoric acid, carbonic acid, boric acid, phenols, saccharides, oximes and fluorinated alcohols. preferable. An alkaline aqueous solution having a pH higher than 8.5 and lower than 13.0 is preferable. 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 IONISATION CONSTANTS OF ORGANIC ACIDS INAQUEOUS SOLUTION published by PergamonPress, and specifically, salicylic acid (13.0) and 3-hydroxy-2-naphthoic acid. (Same as 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 (10.27). , Phenols having a phenolic hydroxyl group such as m- cresol (same 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), picolinthioamide (12.55), val Include the weak acid, such as vine acid (the 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 lithographic printing plate obtained from the photosensitive lithographic printing plate material that can be developed with such a developer is physically fragile and wears quickly during printing. A 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 silicate is preferably 1.0 to 3.0% by mass in terms of SiO ₂ concentration. Further, SiO ₂ and mol ratio of the alkali metal M (SiO ₂ / M) is still preferably be in the range of 0.25 to 2.

  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)
To the developer and replenisher used in the present invention, various surfactants and organic solvents can be added as necessary for the purpose of promoting developability, dispersing development residue, and improving ink affinity of the printing plate image area. Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants.

Preferred examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene aryl ethers, ester polyoxyethylene alkyl phenyl ethers, polyoxyethylene naphthyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene poly ethers. Oxypropylene alkyl 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, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxy Ethyleneated castor oil, polyoxyethylene glycerin fatty acid partial ester, polyoxyethylene-polyoxypropylene block copolymer, polyoxyethylene-polyoxypropylene block copolymer adduct of ethylenediamine, fatty acid diethanolamides, N, N -Nonionic surfactants such as bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides,
Fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, polyoxyethylene aryl ethers Carboxylic acid, polyoxyethylene naphthyl ether sulfate, alkyl diphenyl ether sulfonate, alkyl phenoxy polyoxyethylene propyl sulfonate, polyoxyethylene alkyl sulfophenyl ether, polyoxyethylene aryl ether sulfate, N-methyl- N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, Fatty acid alkyl ester sulfate ester salt, alkyl sulfate ester salt, polyoxyethylene alkyl ether sulfate ester salt, fatty acid monoglyceride sulfate ester salt, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl Phosphate salts, polyoxyethylene alkyl ether phosphate salts, polyoxyethylene alkylphenyl ether phosphate salts, partially saponified styrene / maleic anhydride copolymers, olefin / maleic anhydride copolymer parts Anionic surfactants such as saponified products, naphthalene sulfonate formalin condensates,
Alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, cationic surfactants such as polyoxyethylene alkylamine salts, polyethylene polyamine derivatives, carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates And 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 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, a water-soluble polyalkylene compound, and the like.

(Organic solvent)
If necessary, an organic solvent is added to the developer and the development 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 usually 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 is to prevent stains on the printing plate, and preferred organic reducing agents include phenol compounds such as thiosalicylic acid, hydroquinone, metol, methoxyquinone, resorcin, 2-methylresorcin, and amine compounds such as phenylenediamine and phenylhydrazine. Is mentioned. More preferable inorganic reducing agents include sodium salt, potassium salt, ammonium salt of inorganic acids such as sulfurous acid, bisulfite, phosphorous acid, hydrogen phosphite, phosphorous acid dihydrogen, 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 developer at the time of use.

(Organic carboxylic acid)
If necessary, an organic carboxylic acid can be further added to the developer and replenisher used in the present invention. 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. The aromatic carboxylic acid is a compound in which a carboxyl group is substituted on a benzene ring, naphthalene ring, anthracene ring or the like, and specifically includes 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. However, when the content is 0.1 to 10% by mass, the effect is sufficient, and another additive is used in combination. Sometimes it does not interfere with dissolution. Therefore, the preferable addition amount is 0.1 to 10% by mass, and more preferably 0.5 to 4% by mass with respect to the developing solution in use.

(Other)
In addition to the above, the following additives can be added to the developer and replenisher used in the present invention in order to improve the development performance. For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, complexes such as [Co (NH ₃ )] ₆ Cl ₃ described in JP-A-59-121336, JP-A-56 Ampholytic polymer electrolytes such as a copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described in JP-A-142258, organometallic surfactants containing Si, Ti, etc. described in JP-A-59-75255, JP And organic boron compounds described in JP-A-59-84241. 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. When the addition amount is within this range, the intended purpose is sufficiently achieved, and there is no adverse effect on the image area such as color loss. The remaining component of the developer and replenisher is water. The conductivity of the obtained developer is more preferably in the range of 5 to 50 mS.

(Concentrated liquid)
It is advantageous in terms of transportation that the developer and replenisher used in the present invention are concentrated solutions in which the water content is less than in use, and 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, a so-called hydrotrope such as toluenesulfonic acid, xylenesulfonic acid and alkali metal salts thereof described in JP-A-6-32081 is preferably used.

<Automatic processor>
In the present invention, the automatic processor used for the development processing is preferably provided with a mechanism for automatically supplying the replenisher with a necessary amount to the developing bath, and preferably has a mechanism for discharging a developer exceeding a certain amount. Preferably, a mechanism for automatically replenishing the developer bath with the required amount of water is provided, preferably a mechanism for detecting plate passing is provided, preferably based on detection of plate passing. Is provided with a mechanism for estimating the processing area of the plate, and preferably the replenishment amount and / or replenishment timing of the replenisher and / or water to be replenished based on the detection of the plate and / or the estimation of the processing area A mechanism for controlling the developer, preferably a mechanism for controlling the temperature of the developer, and preferably a mechanism for detecting the pH and / or conductivity of the developer. Mechanism for controlling the replenishment amount and / or replenishment timing of replenishment solution and / or water attempts to replenish the pH and / or conductivity of the developing solution based on has been granted. 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.

《Post processing》
A plate (lithographic printing plate) developed with a developer having such a composition is washed with water, a rinse solution containing a surfactant, etc., a plate surface protective agent (finisher or protective gum solution) mainly composed of gum arabic or starch derivatives, etc. ) Is post-processed. 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, each processing solution can be processed while being replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which treatment is performed with a substantially unused post-treatment liquid can also 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.

<< Plate surface protectant (gum solution) >>
Next, the plate surface protective agent of the present invention used after development processing will be described.

  The plate surface protective agent of the present invention (hereinafter also referred to as gum solution) used in the method for processing a photosensitive lithographic printing plate material of the present invention contains a surfactant having a structure represented by the general formula I according to the present invention. It is characterized by doing. As a result, it is possible to prevent the occurrence of fine spot-like stains (stop stains) that occur in the non-image area when printing is resumed after the printing press has been stopped for a while due to registration or breaks during printing.

  The surfactant having the structure represented by the general formula I according to the present invention will be described.

  The surfactant having the structure represented by the general formula I according to the present invention has a structure in which two molecules of a 1-chain 1-hydrophilic surfactant are linked by a single bond or an organic linking group as shown in the general formula I. It is a dicarboxylic acid having a surface activity superior to that of a one-chain, one-hydrophilic surfactant. In other words, it shows a cmc (critical micelle concentration) of about 1/2000 compared to fatty acid soaps (for example, sodium laurate) having the same HLB (hydrophilic lipophilic balance), Kraft point lower than 0 ° C, fatty acid Hard water resistance 3 times that of soap. These characteristics are presumed to prevent the occurrence of fine spot-like stains (stop stains) that occur in non-image areas when printing is resumed after printing has been stopped for a while due to registration or breaks during printing. The

The alkyl group having 8 to 20 carbon atoms represented by R ₁ and R ₂ may be linear or branched, and may be the same or different, but is preferably a linear alkyl having 10 to 15 carbon atoms. And R ₁ = R ₂ .

Specific examples of the organic linking group having 1 to 20 carbon atoms represented by X include — (CH ₂ ) _n — (n = 1 to 8), —CONH—, —NHCONH—, and combinations thereof. Conceivable. This organic linking group may have a hydrophilic substituent such as —OH or —COOH. Among these linking groups, a single bond is preferable.

  As this type of surfactant, Gemi Surf α102, α142, α182, etc. are available as Gemini type surfactants from Chukyo Yushi Co., Ltd. Among these, the compound (α, α′-bis (carboxymethyl) oxalate dilauryl) having the structure shown in claim 2 is particularly preferable.

  The amount of the surfactant having the structure represented by the general formula I according to the present invention is not particularly limited, but is preferably 0.01 to 20% by mass of the plate surface protective agent (gum solution).

  In the plate surface protective agent (gum solution) used in the present invention, another surfactant can be further added. This improves the surface condition of the coating layer. Surfactants that can be used include anionic surfactants and / or nonionic surfactants. For example, anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinates, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfones. 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 block polymers and the like are preferably used. Fluorine-based and silicon-based anions and nonionic surfactants can also be used.

  Among these, in the present invention, surfactants containing an aromatic hydrophobic group and a polyoxyalkylene group, polyoxyethylene aryl ethers, polyoxyethylene naphthyl ether, and the like are preferably 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.

(Other additives)
In the plate surface protective agent (gum solution) of the present invention, polyhydric alcohols, alcohols and aliphatic hydrocarbons can be used as lubricants as necessary in addition to the above components.

  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.

  Examples of the aliphatic hydrocarbon include n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 3-heptanol, 2-octanol, 2-ethylhexanol, nonanol, 3,5,5-trimethylhexanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, 2-ethyl-1,3-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2,4 -Hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol and the like. The content of these lubricants is preferably 0.1 to 50% by mass, more preferably 0.5 to 3.0% by mass in the composition.

  In addition to the above components, ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin and the like are suitably used as a lubricant if necessary. These wetting agents may be used alone or in combination of two or more. In general, the wetting agent is preferably used in an amount of 1 to 25% by weight.

  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 for a plate surface protecting agent (gum solution) can be suitably 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.

  The plate surface protective agent (gum solution) of the present invention is generally more advantageously used in the acidic range of pH 3-6. 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.

  An antiseptic, an antifoaming agent, and the like can be added to the plate surface protective agent (gum solution) of the present invention. For example, as a preservative, phenol or a derivative thereof, formalin, imidazole derivative, sodium dehydroacetate, 4-isothiazolin-3-one derivative, benzisothiazolin-3-one, benztriazole derivative, amiding anidine derivative, quaternary ammonium salt, pyridine, Examples thereof include derivatives such as quinoline and guanidine, diazine, triazole derivatives, oxazole, and oxazine derivatives. 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 plate surface protective agent (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.

  Furthermore, 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 plate surface protective agent (gum), and a more preferable range is 0.05 to 5% by mass.

  The above-mentioned sensitizing agent may be prepared by emulsifying and dispersing a plate surface protective agent (gum) as an oil phase, or may be solubilized with the help of a solubilizing agent.

In the present invention, the solid content concentration of the plate surface protective agent (gum solution) is preferably 5 to 30 g / l. The film thickness of the plate surface protective agent (gum) can be controlled by the conditions of the squeeze means of the automatic machine. In the present invention, the coating amount of the plate surface protective agent (gum) is preferably 1 to 10 g / m ² . The coating amount of the plate surface protective agent (gum) is preferably 1 g / m ² or more because uniform coating is easy and stable processability is obtained. On the other hand, when it is 10 or less, the plate surface can be dried in a short time without making it very high temperature, which is advantageous in terms of cost and safety, and the effects of the present invention can be sufficiently obtained.

  In the present invention, the time from the end of application of the plate surface protective agent (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 10 seconds. A drying time of 10 seconds or less is preferable because the effects of the present invention can be obtained. When the drying time is 1 second or longer, the photosensitive lithographic printing plate is sufficiently dried, so that it is not necessary to make the plate surface very hot, which is 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 plate surface protecting agent (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 plate surface protective agent (gum liquid), but in the case of a plate surface protective agent (gum liquid) whose solvent is water, the drying temperature is usually 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.

<Washing water before development>
In the present invention, it is preferable to provide a washing step before development. The cleaning solution used in the cleaning step before development is usually water, but the following additives can 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 preferably 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 mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, iethylene glycol fatty acid ester, polyiglycerin fatty acid partial ester, polyoxyethylenated castor oil , Polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-hydroxyalkylamine , 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.

  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 plate surface protecting agent (gum) drawing can be performed. The pre-development rinse water that has been used once or more can be reused in post-development rinse water, a rinse solution, and a plate surface protective agent (gum solution).

<< Photosensitive planographic printing plate material >>
A photosensitive lithographic printing plate material in which a photosensitive layer made of a photosensitive resin composition is formed on an aluminum support used in the present invention will be described.

  The photosensitive lithographic printing plate material used in the present invention is a photosensitive lithographic plate of the type that forms a latent image with a resin (phenolic resin) whose solubility in an alkaline aqueous solution changes as a result of exposure as a photosensitive resin composition of a photosensitive layer. Various materials such as a printing plate material, a photopolymerizable photosensitive lithographic printing plate material of a type that forms a latent image by a free radical reaction by a combination of a photo free radical generator and an ethylenically unsaturated compound, etc. may be used. it can. Among these, a photopolymerizable photosensitive lithographic printing plate material is preferably used.

<< Photopolymerizable photosensitive composition >>
A bromine compound having a structure represented by the following general formula (1) as a preferred photopolymerization initiator of the photopolymerizable photosensitive composition used in the photosensitive layer of the photopolymerizable photosensitive lithographic printing plate material used in the present invention, Examples thereof include titanocene compounds, monoalkyltriaryl borate compounds, and iron arene complex compounds.

Formula (1) R ¹ —CBr ₂ — (C═O) —R ²
In the formula, R ¹ represents a hydrogen atom, a bromine atom, an alkyl group, an aryl group, an acyl group, an alkylsulfonyl group, an arylsulfonyl group, or a cyano group. R ² represents a monovalent substituent. R ¹ and R ² may be bonded to form a ring.

Formula (2) CBr ₃ — (C═O) —X—R ³
R ³ represents a monovalent substituent. X represents —O— or —NR ⁴ —. R ⁴ represents a hydrogen atom or an alkyl group. R ³ and R ⁴ may be bonded to form a ring.

  Examples of the titanocene compound include compounds described in JP-A-63-41483 and JP-A-2-291. More preferred specific examples include bis (cyclopentadienyl) -Ti-di-chloride. , Bis (cyclopentadienyl) -Ti-bis-phenyl, bis (cyclopentadienyl) -Ti-bis-2,3,4,5,6-pentafluorophenyl, bis (cyclopentadienyl) -Ti -Bis-2,3,5,6-tetrafluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4,6-trifluorophenyl, bis (cyclopentadienyl) -Ti-bis-2 , 6-difluorophenyl, bis (cyclopentadienyl) -Ti-bis-2,4-difluorophenyl, bis (methylcyclopentadienyl) -Ti-bi -2,3,4,5,6-pentafluorophenyl, bis (methylcyclopentadienyl) -Ti-bis-2,3,5,6-tetrafluorophenyl, bis (methylcyclopentadienyl) -Ti -Bis-2,6-difluorophenyl (IRGACURE 727L: manufactured by Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium (IRGACURE 784: Ciba Specialty Chemicals), bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyridin-1-yl) phenyl) titanium bis (cyclopentadienyl) -bis (2, 4,6-trifluoro-3- (2-5-dimethylpy-1-yl) phenyl) titanium and the like It is.

  Examples of the monoalkyl triaryl borate compound include compounds described in JP-A-62-154024 and JP-A-62-143044, and more preferable specific examples include tetra-n-butylammonium n- Butyl-trinaphthalen-1-yl-borate, tetra-n-butylammonium / n-butyl-triphenyl-borate, tetra-n-butylammonium / n-butyl-tri- (4-tert-butylphenyl) -borate Tetra-n-butylammonium · n-hexyl-tri- (3-chloro-4-methylphenyl) -borate, tetra-n-butylammonium · n-hexyl-tri- (3-fluorophenyl) -borate and the like. Can be mentioned.

  Examples of the iron arene complex compound include compounds described in JP-A-59-219307, and more preferable specific examples include η-benzene- (η-cyclopentadienyl) iron / hexafluorophosphate, η -Cumene- (η-cyclopentadienyl) iron / hexafluorophosphate, η-fluorene- (η-cyclopentadienyl) iron / hexafluorophosphate, η-naphthalene- (η-cyclopentadienyl) iron / hexa Fluorophosphate, η-xylene- (η-cyclopentadienyl) iron • hexafluorophosphate, η-benzene- (η-cyclopentadienyl) iron • tetrafluoroborate and the like.

  In addition, any photopolymerization initiator can be used in combination. For example, J. et al. Carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo, diazo compounds, halogen compounds, and photoreductive dyes as described in Chapter 5 of “Light Sensitive Systems” by J. Kosar Etc. More specific compounds are disclosed in British Patent 1,459,563.

  That is, the following can be used as a photopolymerization initiator that can be used in combination.

  Benzoin derivatives such as benzoin methyl ether, benzoin-i-propyl ether, α, α-dimethoxy-α-phenylacetophenone; benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis (dimethyl) Benzophenone derivatives such as amino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-i-propylthioxanthone; anthraquinone derivatives such as 2-chloroanthraquinone and 2-methylanthraquinone; N-methylacridone, N-butylacridone and the like In addition to α, α-diethoxyacetophenone, benzyl, fluorenone, xanthone and uranyl compounds, JP-B-59-1281, 61-9621 and JP-A-60-60104 Triazine derivatives; organic peroxides described in JP-A-59-1504 and JP-A-61-243807; JP-B-43-23684, JP-A-44-6413, JP-A-44-6413, JP-A-47-1604, and US patents Diazonium compounds described in US Pat. No. 3,567,453; organic azide compounds described in US Pat. Nos. 2,848,328 and 2,852,379 and 2,940,853; O-quinonediazides described in JP-A Nos. 13109, 38-18015 and 45-9610; JP-B-55-39162, JP-A-59-14023 and “Macromolecules”, Vol. 10, 1307 Various onium compounds described on page 1977; azo compounds described in JP-A-59-142205 Compound: JP-A-1-54440, European Patents 109,851, 126,712 and “Journal of Imaging Science (J. Imag. Sci.)”, Vol. 30, 174 (1986) (Oxo) sulfonium organoboron complexes described in Japanese Patent Application Nos. 4-56831 and 4-89535; "Coordination Chemistry Review", 84, 85-277 (1988) ) And transition metal complexes containing a transition metal such as ruthenium described in JP-A-2-182701; 2,4,5-triarylimidazole dimer described in JP-A-3-209477; carbon tetrabromide, JP Organic halogen compounds described in JP-A-59-107344, etc.

  When laser light is used as the light source, a sensitizing dye is preferably added to the photosensitive layer. It is preferable to use a dye having an absorption maximum wavelength in the vicinity of the wavelength of the light source.

  Examples of compounds for wavelength sensitization from visible light to near infrared include cyanine, phthalocyanine, merocyanine, porphyrin, spiro compound, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, polyene, azo compound, diphenylmethane, triphenyl Ketone alcohol borate complexes such as methane, polymethine acridine, coumarin, coumarin derivatives, ketocoumarin, quinacridone, indigo, styryl, pyrylium compounds, pyromethene compounds, pyrazolotriazole compounds, benzothiazole compounds, barbituric acid derivatives, thiobarbituric acid derivatives, etc. Further, European Patent No. 568,993, US Patent Nos. 4,508,811, 5,227,227, JP 2001-125255 A, JP 11 Compounds described in such Patent 271,969 may also be used.

  Specific examples of the combination of the photopolymerization initiator and the sensitizing dye include combinations described in JP-A Nos. 2001-125255 and 11-271969.

  Although the compounding quantity of these polymerization initiators is not specifically limited, Preferably, it is 0.1-20 mass parts with respect to 100 polymerization parts of compound which can be addition-polymerized or bridge | crosslinked. The mixing ratio of the photopolymerization initiator and the sensitizing dye is preferably in the range of 1: 100 to 100: 1 in terms of molar ratio.

(Addition-polymerizable ethylenic double bond-containing monomer)
A compound containing an ethylenic double bond capable of addition polymerization as a preferred ethylenically unsaturated compound of the photopolymerizable photosensitive composition used in the photosensitive layer of the photopolymerizable photosensitive lithographic printing plate material used in the present invention Use general radical-polymerizable monomers, polyfunctional monomers having multiple addition-polymerizable ethylenic double bonds in the molecule generally used for UV curable resins, and polyfunctional oligomers Can do. The compound is not limited, but preferred examples thereof include 2-ethylhexyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, tetrahydrofurfuryl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate, tetrahydrofurfuryloxyethyl acrylate, tetrahydro Furfuryloxyhexanolide acrylate, acrylate of ε-caprolactone adduct of 1,3-dioxane alcohol, monofunctional acrylic acid esters such as 1,3-dioxolane acrylate, or these acrylates as methacrylate, itaconate, crotonate, maleate Methacrylic acid, itaconic acid, crotonic acid, maleic acid esters such as ethylene glycol diacrylate , Triethylene glycol diacrylate, pentaerythritol diacrylate, hydroquinone diacrylate, resorcin diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, dipentylate of hydroxypivalate neopentyl glycol, Diacrylate of neopentyl glycol adipate, Diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 2- (2-hydroxy-1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1, Ε-caprolactone adduct of 3-dioxane diacrylate, tricyclodecane dimethylol acrylate, tricyclodecane dimethylol acrylate Difunctional acrylic acid esters such as diglycidyl ether diacrylate of 1,6-hexanediol, or methacrylic acid, itaconic acid, crotonic acid, maleic acid ester in which these acrylates are replaced with methacrylate, itaconate, crotonate, maleate, For example, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dipentaerythritol Ε-caprolactone adduct of hexaacrylate, pyrogallol triacrylate Polyfunctional acrylic acid esters such as propionic acid / dipentaerythritol triacrylate, propionic acid / dipentaerythritol tetraacrylate, hydroxypivalylaldehyde-modified dimethylolpropane triacrylate, or these acrylates with methacrylate, itaconate, crotonate, Examples thereof include methacrylic acid, itaconic acid, crotonic acid, and maleic acid ester instead of maleate.

  Prepolymers can also be used as described above. Examples of the prepolymer include compounds as described below, and a prepolymer obtained by introducing acrylic acid or methacrylic acid into an oligomer having an appropriate molecular weight and imparting photopolymerizability can be preferably used. These prepolymers may be used alone or in combination of two or more, and may be used by mixing with the above-mentioned monomers and / or oligomers.

  Examples of prepolymers include adipic acid, trimellitic acid, maleic acid, phthalic acid, terephthalic acid, hymic acid, malonic acid, succinic acid, glutaric acid, itaconic acid, pyromellitic acid, fumaric acid, glutaric acid, pimelic acid, Polybasic acids such as sebacic acid, dodecanoic acid, tetrahydrophthalic acid, and ethylene glycol, propylene glycol, diethylene glycol, propylene oxide, 1,4-butanediol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylol Polyester obtained by introducing (meth) acrylic acid into a polyester obtained by combining polyhydric alcohols such as propane, pentaerythritol, sorbitol, 1,6-hexanediol, 1,2,6-hexanetriol Chlorates such as bisphenol A, epichlorohydrin, (meth) acrylic acid, and epoxy acrylates in which (meth) acrylic acid is introduced into an epoxy resin such as phenol novolac, epichlorohydrin, (meth) acrylic acid, such as ethylene glycol, adipine Acid / tolylene diisocyanate / 2-hydroxyethyl acrylate, polyethylene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate, hydroxyethylphthalyl methacrylate / xylene diisocyanate, 1,2-polybutadiene glycol / tolylene diisocyanate / 2-hydroxyethyl acrylate , Trimethylolpropane, propylene glycol, tolylene diisocyanate, 2-hydroxyethyl acrylate In addition, urethane acrylates in which (meth) acrylic acid is introduced into urethane resin, for example, silicone resin acrylates such as polysiloxane acrylate, polysiloxane diisocyanate, 2-hydroxyethyl acrylate, etc., and (meth) acryloyl in oil-modified alkyd resins Examples thereof include prepolymers such as alkyd-modified acrylates having introduced groups and spirane resin acrylates.

  Photosensitive compositions include phosphazene monomers, triethylene glycol, isocyanuric acid EO (ethylene oxide) modified diacrylate, isocyanuric acid EO modified triacrylate, dimethylol tricyclodecane diacrylate, trimethylolpropane acrylate benzoate, It can contain addition-polymerizable oligomers and prepolymers having monomers such as alkylene glycol type acrylic acid-modified, urethane-modified acrylate and the like and structural units formed from the monomers.

  Furthermore, in the present invention, examples of the ethylenic monomer that can be used in combination include a phosphoric ester compound containing at least one (meth) acryloyl group. The compound is not particularly limited as long as it is a compound in which at least part of the hydroxyl group of phosphoric acid is esterified and has a (meth) acryloyl group.

  In addition, JP-A-58-212994, 61-6649, 62-46688, 62-48589, 62-173295, 62-187092, 63- 67189, JP-A-1-244891, and the like. Further, “11290 Chemical Products”, Chemical Industry Daily, p. 286-p. 294, “UV / EB Curing Handbook (raw material)”, Kobunshi Publishing Co., p. The compounds described in 11 to 65 can also be suitably used in the present invention. Of these, compounds having two or more acrylic groups or methacryl groups in the molecule are preferred in the present invention, and those having a molecular weight of 10,000 or less, more preferably 5,000 or less are preferred.

  In the present invention, it is preferable to use an addition-polymerizable ethylenic double bond-containing monomer containing a tertiary amino group in the molecule. Although there is no particular limitation on the structure, a tertiary amine compound having a hydroxyl group modified with glycidyl methacrylate, methacrylic acid chloride, acrylic acid chloride or the like is preferably used. Specifically, collectable compounds described in JP-A-1-165613, JP-A-1-203413, and JP-A-1-197213 are preferably used.

  Furthermore, the present invention uses a reaction product of a polyhydric alcohol containing a tertiary amino group in the molecule, a diisocyanate compound, and a compound containing an ethylenic double bond capable of addition polymerization with a hydroxyl group in the molecule. Is preferred.

  Examples of the polyhydric alcohol containing a tertiary amino group in the molecule include triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, N-tert-butyldiethanolamine, N, N-di (hydroxyethyl) aniline, N, N, N ′, N′-tetra-2-hydroxypropylethylenediamine, p-tolyldiethanolamine, N, N, N ′, N′-tetra-2-hydroxyethylethylenediamine, N, N-bis (2-hydroxypropyl) aniline, allyldiethanolamine, 3- (dimethylamino) -1,2-propanediol, 3-diethylamino-1,2-propanediol, N, N-di (n -Propyl) amino-2,3-propanediol, N, N-di iso- propyl) amino-2,3-propanediol, 3- (N-methyl--N- benzylamino) -1,2-propanediol - but Le and the like, but are not limited thereto.

  Examples of the diisocyanate compound include butane-1,4-diisocyanate, hexane-1,6-diisocyanate, 2-methylpentane-1,5-diisocyanate, octane-1,8-diisocyanate, 1,3-diisocyanate methyl-cyclohexanone. 2,2,4-trimethylhexane-1,6-diisocyanate, isophorone diisocyanate, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene-2,4-diisocyanate, tolylene- Examples include 2,5-diisocyanate, tolylene-2,6-diisocyanate, 1,3-di (isocyanatomethyl) benzene, 1,3-bis (1-isocyanato-1-methylethyl) benzene, and the like. Limited to Not. As the compound containing an ethylenic double bond capable of addition polymerization with a hydroxyl group in the molecule, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxypropylene-1, Examples include 3-dimethacrylate and 2-hydroxypropylene-1-methacrylate-3-acrylate.

  These reactions can be carried out in the same manner as a method for synthesizing urethane acrylate by a reaction of a normal diol compound, diisocyanate compound, and hydroxyl group-containing acrylate compound.

Specific examples of reaction products of polyhydric alcohols containing tertiary amino groups in the molecule, diisocyanate compounds, and compounds containing ethylenic double bonds capable of addition polymerization with hydroxyl groups in the molecule are shown below. Shown in
M-1: reaction product of triethanolamine (1 mol), hexane-1,6-diisocyanate (3 mol), 2-hydroxyethyl methacrylate (3 mol) M-2: triethanolamine (1 mol), isophorone Reaction product of diisocyanate (3 mol) and 2-hydroxyethyl acrylate (3 mol) M-3: Nn-butyldiethanolamine (1 mol), 1,3-bis (1-isocyanate-1-methylethyl) Reaction product of benzene (2 mol), 2-hydroxypropylene-1-methacrylate-3-acrylate (2 mol) M-4: Nn-butyldiethanolamine (1 mol), 1,3-di (isocyanatomethyl) ) Reaction of benzene (2 mol), 2-hydroxypropylene-1-methacrylate-3-acrylate (2 mol) Product M-5: Reaction product of N-methyldiethanolamine (1 mol), tolylene-2,4-diisocyanate (2 mol), 2-hydroxypropylene-1,3-dimethacrylate (2 mol) An acrylate or an alkyl acrylate described in JP-A-1-105238 and JP-A-2-127404 can be used.

<Polymer binder>
The photopolymerizable photosensitive lithographic printing plate used in the present invention contains a polymer binder in the photopolymerizable photosensitive layer.

  Examples of the polymer binder of the present invention include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, and other natural materials. Resin etc. can be used. Two or more of these may be used in combination.

  A vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, the copolymer composition of the polymer binder is preferably a copolymer of (a) a carboxyl group-containing monomer, (b) a methacrylic acid alkyl ester, or an acrylic acid alkyl ester.

  Specific examples of the carboxyl group-containing monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride and the like. In addition, carboxylic acids such as phthalic acid and 2-hydroxymethacrylate half ester are also preferable.

  Specific examples of alkyl methacrylates and alkyl esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate. , Decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, acrylic In addition to unsubstituted alkyl esters such as decyl acid, undecyl acrylate and dodecyl acrylate, cyclic alkyl esters such as cyclohexyl methacrylate and cyclohexyl acrylate Substituted alkyl esters such as benzyl methacrylate, 2-chloroethyl methacrylate, N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate, benzyl acrylate, 2-chloroethyl acrylate, N, N-dimethylaminoethyl acrylate, and glycidyl acrylate Also mentioned.

  Furthermore, in the polymer binder of the present invention, monomers described in the following (1) to (14) can be used as other copolymerization monomers.

  1) Monomers having an aromatic hydroxyl group, such as o- (or p-, m-) hydroxystyrene, o- (or p-, m-) hydroxyphenyl acrylate and the like.

  2) Monomers having an aliphatic hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-methylol methacrylamide, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 5-hydroxypentyl methacrylate , 6-hydroxyhexyl acrylate, 6-hydroxyhexyl methacrylate, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, hydroxyethyl vinyl ether and the like.

  3) A monomer having an aminosulfonyl group, such as m- (or p-) aminosulfonylphenyl methacrylate, m- (or p-) aminosulfonylphenyl acrylate, N- (p-aminosulfonylphenyl) methacrylamide, N- (p -Aminosulfonylphenyl) acrylamide and the like.

  4) Monomers having a sulfonamide group, such as N- (p-toluenesulfonyl) acrylamide, N- (p-toluenesulfonyl) methacrylamide and the like.

  5) Acrylamide or methacrylamides such as acrylamide, methacrylamide, N-ethylacrylamide, N-hexylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (4-nitrophenyl) acrylamide, N-ethyl-N- Phenylacrylamide, N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like.

  6) Monomers containing fluorinated alkyl groups such as trifluoroethyl acrylate, trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadecafluorodecyl methacrylate, N- Butyl-N- (2-acryloxyethyl) heptadecafluorooctylsulfonamide and the like.

  7) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether and the like.

  8) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate and the like.

  9) Styrenes such as styrene, methyl styrene, chloromethyl styrene and the like.

  10) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.

  11) Olefins such as ethylene, propylene, i-butylene, butadiene, isoprene and the like.

  12) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine and the like.

  13) Monomers having a cyano group, such as acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o- (or m-, p-) cyanostyrene.

  14) A monomer having an amino group, such as N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, polybutadiene urethane acrylate, N, N-dimethylaminopropyl acrylamide, N, N-dimethylacrylamide, acryloylmorpholine, Ni-propylacrylamide, N, N-diethylacrylamide and the like.

  Further, other monomers that can be copolymerized with these monomers may be copolymerized.

  Furthermore, an unsaturated bond-containing vinyl copolymer obtained by addition-reacting a compound having a (meth) acryloyl group and an epoxy group in the molecule to a carboxyl group present in the molecule of the vinyl copolymer. Is also preferred as a polymer binder.

  Specific examples of the compound containing both an unsaturated bond and an epoxy group in the molecule include glycidyl acrylate, glycidyl methacrylate, and an epoxy group-containing unsaturated compound described in JP-A No. 11-271969.

  These copolymers preferably have a weight average molecular weight of 1 to 200,000 as measured by gel permeation chromatography (GPC), but are not limited to this range.

  The content of the high molecular polymer in the photosensitive layer composition is preferably in the range of 10 to 90% by mass, more preferably in the range of 15 to 70% by mass, and the sensitivity to use in the range of 20 to 50% by mass. Particularly preferred from the viewpoint.

  Furthermore, the acid value of the resin is preferably used in the range of 10 to 150, more preferably in the range of 30 to 120, and the use in the range of 50 to 90 from the viewpoint of balancing the polarity of the entire photosensitive layer. Particularly preferred, this can prevent pigment aggregation in the photosensitive layer coating solution.

《Oxygen barrier layer》
The photopolymerizable photosensitive lithographic printing plate material used in the present invention is preferably provided with an oxygen blocking layer. For the oxygen barrier layer, a water-soluble polymer capable of forming a film having low oxygen permeability is used. Specifically, it contains polyvinyl alcohol and polyvinyl pyrrolidone. Polyvinyl alcohol has an effect of suppressing permeation of oxygen, and polyvinyl pyrrolidone has an effect of ensuring adhesion with an adjacent photosensitive layer.

  In addition to the above two polymers, polysaccharides, polyethylene glycol, gelatin, glue, casein, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxyethyl starch, gum arabic, sucrose octaacetate, ammonium alginate, sodium alginate as required Water-soluble polymers such as polyvinylamine, polyethylene oxide, polystyrene sulfonic acid, polyacrylic acid, and water-soluble polyamide can also be used in combination.

  The peeling force between the photosensitive layer and the overcoat layer is preferably 35 g / 10 mm or more, more preferably 50 g / 10 mm or more, still more preferably 75 g / 10 mm or more. Preferred overcoat layer compositions include those described in Japanese Patent Application No. 8-161645.

  In the present invention, the peeling force is determined by applying an adhesive tape having a predetermined width on the overcoat layer and peeling it together with the overcoat layer at an angle of 90 degrees with respect to the plane of the planographic printing plate material. The force of was measured.

  The overcoat layer can further contain a surfactant, a matting agent and the like as required. The overcoat layer composition is dissolved in a suitable solvent, applied onto the photosensitive layer and dried to form an overcoat layer. The main component of the coating solvent is particularly preferably water or alcohols such as methanol, ethanol, i-propanol.

  The thickness of the overcoat layer is preferably from 0.1 to 5.0 μm, particularly preferably from 0.5 to 3.0 μm.

(Image exposure)
Examples of the light source for image exposure of the lithographic printing plate material include lasers, light emitting diodes, xenon lamps, xenon flash lamps, halogen lamps, carbon arc lamps, metal halide lamps, tungsten lamps, high pressure mercury lamps, and electrodeless light sources.

  In the case of batch exposure, a mask material in which a negative pattern of a desired exposure image is formed of a light-shielding material may be superimposed on the photopolymerizable photosensitive layer and exposed.

  When using an array-type light source such as a light-emitting diode array, or when controlling exposure of a light source such as a halogen lamp, metal halide lamp, or tungsten lamp with an optical shutter material such as liquid crystal or PLZT, digital Exposure is possible and preferable. In this case, direct writing can be performed without using a mask material.

  Laser exposure is suitable for direct writing without using a mask material because light exposure can be performed in the form of a beam according to image data. When a laser is used as a light source, it is easy to reduce the exposure area to a very small size, and high-resolution image formation is possible.

  Laser scanning methods include cylindrical outer surface scanning, cylindrical inner surface scanning, and planar scanning. In the cylindrical outer surface scanning, laser exposure is performed while rotating a drum around which the recording material is wound, and the rotation of the drum is the main scanning and the movement of the laser light is the sub scanning. In cylindrical inner surface scanning, a recording material is fixed to the inner surface of the drum, a laser beam is irradiated from the inside, and a main scanning is performed in the circumferential direction by rotating a part or all of the optical system. Sub scanning is performed in the axial direction by linearly moving all of them in parallel with the drum axis. In plane scanning, a laser beam main scan is performed by combining a polygon mirror, a galvanometer mirror, and an fθ lens, and a sub-scan is performed by moving a recording medium. Cylindrical outer surface scanning and cylindrical inner surface scanning are easier to increase the accuracy of the optical system and are suitable for high-density recording.

(Automatic processor)
In the present invention, a method of developing a lithographic printing plate material using an automatic developing machine is a preferable embodiment because the effects of the present invention are effective.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. In addition, unless otherwise indicated, "part" in an Example shows a "mass part".

Example 1
(Binder synthesis)
A three-necked flask under a nitrogen stream is charged with 12 parts of methacrylic acid, 70 parts of methyl methacrylate, 8 parts of acrylonitrile, 10 parts of ethyl methacrylate, 500 parts of ethanol and 3 parts of α, α'-azobisisobutyronitrile. The reaction was carried out in an air stream at 80 ° C. for 6 hours. Thereafter, 3 parts of triethylammonium chloride and 2 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 50,000, 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 0.24 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% by mass 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 3% by mass oxalic acid. A support was prepared by sealing with sodium at 90 ° C.

  At this time, the center line average roughness (Ra) of the surface was 0.65 μm.

(Installation of undercoat layer on support)
On the support, an undercoat layer coating solution having the following composition is applied with a wire bar so as to be 0.1 g / m ² when dried, dried at 90 ° C. for 1 minute, and further heated at 110 ° C. for 3 minutes. The under-drawn support was prepared.

Undercoat layer coating solution γ-methacryloxyxypropyltrimethoxysilane 1 part by weight Methyl ethyl ketone 80 parts by weight Cyclohexanone 19 parts by weight << Preparation of lithographic printing plate material 1-1 >>
On the undercoated support, a photopolymerizable photosensitive layer coating solution having the following composition was applied with a wire bar so as to be 1.4 g / m ² when dried, and dried at 95 ° C. for 1.5 minutes. Thereafter, an overcoat layer coating solution having the following composition is further applied onto the photosensitive layer with an applicator so as to have a dry weight of 2.0 g / m ² and dried at 75 ° C. for 1.5 minutes. A photosensitive lithographic printing plate material 1-1 having an overcoat layer on the layer was produced.

Photopolymerizable photosensitive layer coating solution Acrylic copolymer 1 (synthetic binder, molecular weight Mw = 50,000) 35.0 parts by weight Spectral sensitizing dye 1 2.0 parts by weight Spectral sensitizing dye 2 2.0 parts by weight IRGACURE 784 (manufactured by Ciba Specialty Chemicals) 4.0 parts by mass EO-modified tris (acryloxyethyl) isocyanuric acid (Aronix M-315: manufactured by Toagosei Co., Ltd.) 35.0 parts by mass Polytetramethylene glycol diacrylate (PTMGA-250: Kyoeisha) 10.0 parts by mass polyfunctional urethane acrylate (U-15HA: made by Shin-Nakamura Chemical Co., Ltd.) 5.0 parts by mass phthalocyanine pigment (MHI454: made by Gokoku Colors) 6.0 parts by mass 2-t-butyl -6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate Riser GS: manufactured by Sumitomo 3M Co., Ltd.) 0.5 parts by mass Fluorosurfactant (FC-431; manufactured by Sumitomo 3M) 0.5 parts by mass Methyl ethyl ketone (boiling point = 79.6 ° C) 80 parts by mass Cyclopentanone (boiling point) = 129 ° C) 820 parts by mass Overcoat layer coating solution Polyvinyl alcohol (GL-03: manufactured by Nippon Synthetic Chemical Co., Ltd.) 89 parts by mass Water-soluble polyamide (P-70: manufactured by Toray Industries, Inc.) 10 parts by mass Surfactant (F142D: Dainippon Ink & Chemicals, Inc.) 0.5 parts by weight water 900 parts by weight

<< Exposure, development processing, plate surface protective agent (gum solution) treatment, preparation of lithographic printing plate >>
An image with a resolution of 1200 dpi (dpi represents the number of dots per 2.54 cm) using a plate setter (Tiger Cat: manufactured by ECRM) CTP exposure apparatus equipped with a light source having a laser of 408 nm and 30 mW output. Exposure (exposure pattern used 100% image area and 100 lpi 50% square dots) was performed. Then, a preheating part, a pre-water washing part, a developing part (developing liquid 22L in the bathtub), an alkaline aqueous solution processing part (alkaline aqueous solution 15L in the bathtub), a washing part, a finisher liquid (plate surface protective agent (gum liquid)) processing part, Using the following developer, developer replenisher, and plate surface protective agent (gum solution) with a CTP automatic processor (Raptor 85HW polymer; manufactured by Glunz and Jensen) equipped with each processing unit in the order of the drying unit, Development was carried out for 300 m ² over 2 weeks so that the area ratio of the image area to the non-image area was 2: 8 to prepare a lithographic printing plate. The developing unit supplemented with developer replenisher to approximately 60 ml / m ^2.

<Developer formulation>
Potassium silicate aqueous solution (SiO ₂ 26 mass%, K ₂ O 13.5 mass%)
30.0 g / L
Ethylenediaminetetraacetic acid disodium salt 0.2g / L
Polyoxyethylene (13) naphthyl ether 40.0 g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.3
<Development replenisher formulation>
Potassium silicate aqueous solution (SiO ₂ 26 mass%, K ₂ O 13.5 mass%)
30.0 g / L
Ethylenediaminetetraacetic acid disodium salt 0.2g / L
Polyoxyethylene (13) naphthyl ether 40.0 g / L
Potassium hydroxide The following pH level The remaining component is water. pH: 12.7
<Plate surface protectant (gum solution (finisher solution)) prescription>
(Plate surface protectant (gum solution)) (1L aqueous solution formulation)
White dextrin 5.0% by mass
Hydroxypropyl etherified starch 10.0% by mass
Gum arabic 1.0% by mass
Surfactant of the present invention (compounds 1, 2, 3) (type described in Table 1) 0.5% by mass
1st Ammon Phosphate 0.1% by mass
Sodium dilauryl succinate 0.15% by mass
Polyoxyethylene naphthyl ether 0.5% by mass
Polyoxyethylene polyoxypropylene block copolymer (ethylene oxide ratio 50 mol%, molecular weight 5000) 0.3 mass%
Ethylene glycol 1.0% by mass
Ethylenediaminetetraacetic acid disodium 0.005 mass%
1,2 benzoisothiazolin-3-one 0.005 mass%
Finish to 1L with water.

"printing"
(Evaluation of stop dirt)
The prepared lithographic printing plate is applied to a printing press (DAIYA 1F-1 manufactured by Mitsubishi Heavy Industries, Ltd.), coated paper, dampening water (etching solution SG-51 concentration 1.5% manufactured by Tokyo Ink Co., Ltd.), ink (Toyo Ink Manufacturing Co., Ltd.) When printing 5000 sheets, stop the press once, leave it for 1 hour, start printing (resume), and generate fine dot-like stains (stop) Dirt) was evaluated by visual observation with a number within 100 cm ² . (Good is 20 or less. Use of 30 or more is not practical.)
The results are shown in Table 1.

  As is apparent from Table 1, in the case of the present invention, it can be seen that it is excellent in preventing the occurrence of stop dirt.

  According to the present invention, a photosensitive lithographic printing plate capable of preventing the occurrence of fine spot-like stains (stop stains) generated in a non-image area when printing is resumed after stopping the printing press for a while due to registration or break during printing. It can be seen that a material processing method and a plate surface protecting agent for a photosensitive lithographic printing plate material can be provided.

Claims (6)

A photosensitive lithographic printing plate material in which a photosensitive layer composed of a photosensitive resin composition is formed on an aluminum support is exposed, developed with a developer, and then processed with a plate surface protective agent. In the processing method of printing plate material, The plate surface protecting agent contains surfactant of the structure shown by the following general formula I, The processing method of photosensitive lithographic printing plate material characterized by the above-mentioned.

(In the formula, R ₁ and R ₂ each independently represents an alkyl group having 8 to 20 carbon atoms, and X represents a single bond or an organic linking group having 1 to 20 carbon atoms.) The method for processing a photosensitive lithographic printing plate material according to claim 1, wherein the surfactant having the structure represented by the general formula I is the following compound 1.

The method for processing a photosensitive lithographic printing plate material according to claim 1 or 2, wherein the plate surface protective agent further contains a surfactant containing an aromatic hydrophobic group and a polyalkylene group. Photosensitive lithographic printing plate used for treatment with a plate surface protective agent after exposure and development treatment with a developer of a photosensitive lithographic printing plate material having a photosensitive layer composed of a photosensitive resin composition on an aluminum support A plate surface protective agent for a photosensitive lithographic printing plate material, wherein the plate surface protective agent contains a surfactant having a structure represented by the following general formula I:

(In the formula, R ₁ and R ₂ each independently represents an alkyl group having 8 to 20 carbon atoms, and X represents a single bond or an organic linking group having 1 to 20 carbon atoms.) 5. The plate surface protective agent for a photosensitive lithographic printing plate material according to claim 4, wherein the surfactant having the structure represented by the general formula I is the following compound 1.

6. The plate surface protective agent for a photosensitive lithographic printing plate material according to claim 4, wherein the plate surface protective agent further contains a surfactant containing an aromatic hydrophobic group and a polyalkylene group.