JP4813432B2 - Planographic printing plate making method - Google Patents

Description

  The present invention relates to a method for making a lithographic printing plate from a lithographic printing plate precursor having a backcoat layer containing an organic polymer compound.

Conventionally, PS plates having a constitution in which an oleophilic photosensitive resin layer is provided on a hydrophilic support as a lithographic printing plate precursor have been widely used. After exposure), the desired printing plate was obtained by dissolving and removing the non-image area.
In recent years, digitization techniques that electronically process, store, and output image information using a computer have become widespread. Various new image output methods corresponding to such digitization techniques have come into practical use. As a result, computer-to-plate (CTP) technology that scans highly directional light such as laser light according to digitized image information and directly produces a printing plate without going through a lithographic film is eagerly desired. A planographic printing plate precursor adapted to this is being developed.

Such a lithographic printing plate precursor has an anti-adhesion function between the original plates, and a relatively soft photosensitive layer or a protective layer surface provided on the photosensitive layer rubs against an aluminum support or a back coat layer provided on the back surface of the support. In order to prevent scratches caused by this, it is supplied as a laminate in which slip sheets are inserted between the original plates. However, if the slip sheet is present, unnecessary waste is generated, and the slip sheet removal time in the exposure process causes the productivity to be inefficient. In order to solve these problems by eliminating the interleaving paper, the adhesion resistance between the lithographic printing plate precursors and the scratches caused by rubbing the photosensitive layer or the surface of the protective layer provided on the photosensitive layer with the aluminum support. Improvement was desired.
In particular, on a hydrophilic support, a photopolymerization type recording layer containing a photopolymerization initiator excellent in photosensitive speed, an addition-polymerizable ethylenically unsaturated compound, and a binder polymer soluble in an alkali developer, and necessary Accordingly, a lithographic printing plate precursor (for example, see Patent Document 1) provided with an oxygen-blocking protective layer is easily scratched due to the soft photosensitive layer and the presence of the overcoat layer. For improving such scratches, a method of providing a backcoat layer having a Tg of 20 ° C. or higher (for example, see Patent Document 2) and a method of using a polyester resin, a phenoxy resin, or a polyvinyl acetal resin as the backcoat layer (for example, However, the improvement effect is insufficient, and further improvement is demanded.

On the other hand, a lithographic printing plate precursor is usually treated with a plate surface protective solution after exposure and development to become a lithographic printing plate. The purpose of the treatment with the plate surface protection liquid is not only to protect the hydrophilicity of the non-image area, but also to image correction such as addition or correction erasure of the image area, storage for the period until printing after plate making or storage until reuse, It is the so-called desensitization such as prevention of dirt caused by adhesion of fingerprints, oils and fats, dust, etc. during installation and handling, and protection from scratches, etc. .
When the exposed and developed lithographic printing plate is treated with a plate surface protective solution, it is inevitable that the plate surface protective solution wraps around the back surface of the plate, and a plate surface protective layer is also formed on the back surface. However, the plate surface protective layer formed on the back surface of the lithographic printing plate having the back coat layer as described above is easy to peel off, and the peeled one is transported, folded, perforated, stacked, printed, etc. after desensitizing treatment There was a drawback of contaminating the process.
Accordingly, there is a need for a processing method using a plate surface protective liquid that improves the adhesion or scratch resistance of a plate even when no interleaf is present, and at the same time does not peel the plate surface protective layer from the back surface of the planographic printing plate.

Japanese Patent Laid-Open No. 10-228109 JP-A-6-332155 Japanese Patent Laid-Open No. 2005-62456

  Therefore, the present invention suppresses the peeling of the plate surface protective layer from the back surface of the plate when making a plate from a lithographic printing plate precursor having a back coat layer containing an organic polymer compound, and conveys, folds, punches, accumulates, It is an object of the present invention to provide a method for making a lithographic printing plate that does not contaminate a process such as printing.

As a result of intensive studies to achieve the above-mentioned problems, the present inventor obtained a plate surface protective solution containing a specific copolymer when making a plate from a lithographic printing plate precursor having a back coat layer containing an organic polymer compound. By treating with, it is possible to suppress the peeling of the plate surface protective layer from the back side of the plate, and to obtain a clean lithographic printing plate without contaminating the steps of conveyance, folding, hole punching, stacking, printing, etc. I found.
Accordingly, the present invention provides a lithographic plate having a photosensitive recording layer on one side of an aluminum support and a backcoat layer containing an organic polymer compound on the aluminum support opposite to the side having the photosensitive recording layer. This is a plate making method in which a printing plate precursor is imagewise exposed and developed, and then treated with a plate surface protective solution containing a copolymer represented by the following general formula (1).

（式中、ｍ及びｎは共重合比を表し、ｍ＋ｎを１００とするとｍが１０から９０の範囲であり、Ｒは−ＯＨ、−ＯＣＨ₃、及び−ＯＣＯＣＨ₃からなる群から選ばれる少なくとも１種である。）
前記一般式（１）で示される共重合体において、好ましい実施態様としてｍが５５から７５であることが挙げられる。前記一般式（１）で示される共重合体において、Ｒは１種単独でも又は２種以上でもよい。本発明の実施態様としてＲが−ＯＣＯＣＨ₃であることが挙げられる。

(In the formula, m and n represent a copolymerization ratio, where m + n is 100, m is in the range of 10 to 90, and R is at least 1 selected from the group consisting of —OH, —OCH ₃ , and —OCOCH _3. Seeds.)
In the copolymer represented by the general formula (1), m is preferably 55 to 75 as a preferred embodiment. In the copolymer represented by the general formula (1), R may be one kind or two or more kinds. An embodiment of the present invention includes R being —OCOCH ₃ .

Another embodiment of the present invention is that the organic polymer compound contained in the backcoat layer contains an epoxy resin. It is preferable that the organic polymer compound contained in the backcoat layer contains rosin in addition to the epoxy resin. In addition to the epoxy resin, or in addition to the epoxy resin and rosin, there is an embodiment containing a resin having a phenolic hydroxyl group.
In another embodiment of the present invention, the photosensitive recording layer is an infrared absorber, a polymerization initiator, a monomer having two or more phenyl groups substituted with vinyl groups in the molecule, and a phenyl group substituted with vinyl groups. And a polymer having a side chain.
The plate-making method of the present invention is particularly directed to a plate-making method from a lithographic printing plate precursor that can be directly drawn with a laser beam.

According to the plate making method of the lithographic printing plate of the present invention, the plate surface protective layer is formed from the back surface of the lithographic printing plate in the steps such as conveyance, folding, hole punching, stacking and printing after the desensitizing treatment by the treatment of the plate surface protective liquid. Since peeling is suppressed, the above-described process is not contaminated by the plate surface protective layer that has been peeled off as in the prior art, and thus a clean lithographic printing plate can be provided. According to the plate making method of the lithographic printing plate of the present invention, the obtained lithographic printing plate has good ink removal, and less paper is required until a normal printed matter is obtained after printing is started.
According to the plate making method of the lithographic printing plate of the present invention, not only the hydrophilicity of the non-image area is protected, but also image correction such as addition or correction erasure of the image area, storage or re-printing after the plate making is performed. It is possible to obtain a lithographic printing plate that is sufficiently protected from storage, scratching, and the like caused by adhesion of fingerprints, oils and fats, dust, and the like during storage before use, attachment to a printing press, and handling.

（式中、ｍ及びｎは共重合比を表し、ｍ＋ｎを１００とするとｍは１０から９０の範囲であり、Ｒは−ＯＨ、−ＯＣＨ₃、及び−ＯＣＯＣＨ₃からなる群から選ばれる少なくとも１種である。） <Plate surface protection solution>
The plate surface protective liquid used in the method of the present invention is characterized by containing a copolymer represented by the following general formula (1).

(In the formula, m and n represent a copolymerization ratio, where m + n is 100, m is in the range of 10 to 90, and R is at least 1 selected from the group consisting of —OH, —OCH ₃ , and —OCOCH _3. Seeds.)

The structure of the copolymer of the general formula (1) may be a random copolymer type or a block copolymer type. In the copolymer represented by the general formula (1), R may be one kind or two or more kinds. R is preferably —OH or —OCOCH ₃ , and most preferably —OCOCH ₃ . Also,
In the copolymer represented by the general formula (1), when m + n is 100, m is suitably in the range of 30 to 85, more preferably m is in the range of 45 to 80, and most preferably m is from 55. A range of 75. When m is in the range of 30 to 85, it is good in terms of solubility in the plate surface protective liquid and is moderately hydrophilic, and as a result, the effect of improving the adhesion with the hydrophobic backcoat layer is appropriate. Also, ink repellency is good.
The molecular weight of the copolymer represented by the general formula (1) is preferably about 5000 to 100,000. When the molecular weight of the copolymer is within this range, the film-forming property is moderate, the viscosity of the plate surface protective liquid is moderately suppressed, and the discharge with an automatic processor is good.
The content of the copolymer of the general formula (1) in the plate surface protective liquid is 0.1% based on the total mass of the plate surface protective liquid. ˜2 mass% is suitable, more preferably 0.5 to 1 mass%, and most preferably 0.6 to 0.8 mass%.
The copolymer represented by the general formula (1) may be used alone or in combination of two or more.

  Commercially available products can be used as the copolymer of the above general formula (1). Examples of such commercially available products are PVP / VA series (E-335, E-535, E-635) manufactured by ISP Co., Ltd. , E-735, I-335, I-535, I-635, I-735, W-635, W-735, S-630), BASF Corporation's Rubiscor VA series (VA73E, VA73W, VA64P, VA55I, VA37E, VA37I), Rubytec VA64W, etc.

In addition to the above-mentioned compounds, the plate surface protective solution used in the present invention may further comprise a water-soluble polymer compound; an inorganic acid and / or an organic acid and / or a salt thereof; a surfactant other than the above compound; an organic solvent; , Sulfates; chelating agents; preservatives; antifoaming agents and the like. Various components are described below.
It is preferable to add a water-soluble polymer compound having film-forming properties to the plate surface protective liquid in order to maintain the hydrophilicity and protect the plate surface from scratches. Examples of such water-soluble polymer compounds include gum arabic, fiber derivatives (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, hydroxypropylcellulose, methylpropylcellulose, etc.) and modified products thereof, polyvinyl alcohol and derivatives thereof, polyvinylpyrrolidone, and polyacrylamide. And copolymers thereof, vinyl methyl ether / maleic anhydride copolymer, vinyl acetate / maleic anhydride copolymer, styrene / maleic anhydride copolymer, water-soluble soybean polysaccharide, starch derivatives (eg dextrin, enzymatic degradation) Dextrin, hydroxypropylated starch, enzymatically degraded dextrin, carboxymethylated starch, phosphate esterified starch, cyclodextrin), pullulan and pullulan derivatives, extracted from soybean Hemicellulose and the like. Of these, starch derivatives such as gum arabic and dextrin, carboxymethyl cellulose, soybean polysaccharide and the like can be preferably used.
The content of these water-soluble polymer compounds is suitably from 0.1 to 25.0 mass%, more preferably from 0.3 to 20.0 mass%, based on the total mass of the plate surface protective liquid.

  In general, it is more advantageous to use the plate surface protective solution in the acidic range of pH 2 to 6. In order to achieve such a pH, a mineral acid, an organic acid, or a salt thereof is generally added and adjusted in the plate surface protective solution. Examples of the pH adjuster include nitric acid, sulfuric acid, phosphoric acid, metaphosphoric acid, and polyphosphoric acid as mineral acids. Examples of the organic acid include acetic acid, succinic acid, citric acid, malic acid, malonic acid, tartaric acid, p-toluenesulfonic acid, lactic acid, repric acid, phytic acid, and organic phosphonic acid. Preferred salts include disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, potassium pyrophosphate, sodium hexametaphosphate, sodium tripolyphosphate, sodium nitrate , Potassium nitrate, ammonium nitrate, and sodium sulfate. One kind of mineral acid, organic acid or salt thereof may be used alone, or two or more kinds may be used in combination. The addition amount is generally about 0.01 to 3.0% by mass based on the total mass of the plate surface protective liquid.

  The plate surface protective solution used in the present invention may further contain a surfactant, and examples thereof include an anionic surfactant and / or a nonionic surfactant. Anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid salts, alkyl diphenyl ether mono- or disulfonic acid salts, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid Salts, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkylsulfosuccinic acid monoamide disodium salt, petroleum sulfone Acid salts, sulfated castor oil, sulfated beef tallow oil, sulfate esters of fatty acid alkyl esters, alkyl sulfate salts, polyoxyethylene alkyl -Ter sulfate, fatty acid monoglyceride sulfate, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene styrylphenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkylphenyl Examples thereof include ether phosphate esters, partially saponified styrene-maleic anhydride copolymers, partially saponified olefin-maleic anhydride copolymers, and naphthalene sulfonate formalin condensates. Among these, dialkyl sulfosuccinates, alkyl sulfate esters, alkyl naphthalene sulfonates and alkyl diphenyl ether mono- or disulfonates are particularly preferably used.

Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, Sugar fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene castor oil ether, polyoxyethylene sorbitol fatty acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, polyoxyethylene glycerin fatty acid partial ester , Fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamine, tri Ethanolamine fatty acid esters, such as trialkylamine oxides. Of these, polyoxyethylene alkyl ethers, polyoxyethylene-polyoxypropylene block copolymers, polyoxyethylene castor oil ether, and the like are preferably used.
Acetylene glycol-based and acetylene alcohol-based oxyethylene adducts, fluorine-based and silicon-based anions, and nonionic surfactants can also be used in the same manner.

Two or more of these surfactants 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. These compounds are preferably selected and used in consideration of environmental effects.
The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by mass in the plate surface protective solution.

  An organic solvent having a boiling point of 130 ° C. or higher can be added to the plate surface protective solution used in the present invention in order to protect the oil sensitivity of the image area. This type of organic solvent, on the other hand, functions to remove the trace amount of remaining photosensitive film adhering to the non-image area hydrophilic layer and to enhance the hydrophilicity of the non-image area. Specific examples of organic solvents having a boiling point of 130 ° C. or higher include alcohols such as n-hexanol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethylhexanol, Examples include 3,5,5-trimethylhexanol, nonanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, tetradecanol, cyclohexanol, benzyl alcohol, and tetrahydrofurfuryl alcohol. Examples of ketones include methyl-n-amyl ketone, methyl-n-hexyl ketone, ethyl-n-butyl ketone, di-n-propyl ketone, diacetone alcohol, and cyclohexanone. Esters include benzoates such as n-amyl acetate, isoamyl acetate, methyl isoamyl acetate, methoxybutyl acetate, benzyl acetate, ethyl lactate, butyl lactate, n-amyl lactate, methyl benzoate, ethyl benzoate, and benzyl benzoate. Phthalic acid diesters such as acid esters, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dinonyl phthalate, didecyl phthalate, dilauryl phthalate, butyl benzyl phthalate Dioctyl adipate, butyl glycol adipate, dioctyl azelate, dibutyl sebacate, di (2-ethylhexyl) sebacate, dioctyl sebacate and other dibasic acid esters, for example, epoxidized triglycerides such as epoxidized soybean oil And phosphoric acid esters such as tricresyl phosphate, trioctyl phosphate, and tristrolol phosphate.

Polyhydric alcohols and their derivatives include ethylene glycol, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol butyl ether, ethylene glycol dibutyl ether, ethylene glycol isoamyl ether, ethylene glycol monophenyl ether, ethylene glycol monophenyl ether Acetate, ethylene glycol benzyl ether, ethylene glycol monohexyl ether, methoxyethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl Ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol, propylene glycol, dipropylene glycol, propylene glycol monoethyl ether, propylene glycol monobutyl ether, 1 -Butoxyethoxypropanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, butylene glycol, hexylene glycol, octylene glycol, glycerin, diglycerin It may be mentioned trimethylolpropane, glycerol monoacetate, glycerol triacetates.
Examples of hydrocarbons include aromatics, aliphatic compounds, squalane and the like of petroleum fractions having a boiling point of 160 ° C. or higher.
Conditions for selecting the organic solvent include environmental safety, particularly odor. These solvents may be used alone or in combination of two or more. The amount used is suitably 0.1 to 5.0% by mass, more preferably 0.3 to 3.0% by mass in the plate surface protective solution.
In the plate surface protective solution used in the present invention, these organic solvents may be solubilized with a surfactant to be a solution type, or emulsified and dispersed as an oil phase to be an emulsified type.

  Examples of nitrates and sulfates that can be included in the plate surface protective solution include magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium hydrogen sulfate, nickel sulfate, and the like. The amount of these used is 0.05 to 1.0% by mass in the plate surface protective liquid.

Usually, the plate surface protective solution is commercially available as a concentrated solution, and is used after being diluted by adding tap water, well water, or the like. Calcium ions contained in the diluted tap water and well water may adversely affect printing and may cause the printed matter to become dirty. Therefore, the above disadvantages can be eliminated by adding a chelate compound. . Preferred chelate compounds include, for example, Na ₂ P ₂ O ₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO ₃ P) PO ₃ Na ₂ , calgon (sodium polymetaphosphate). Such as polyphosphate, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt; dihydroxyethylglycine, its potassium salt, its sodium salt; hydroxyiminodiacetic acid, its potassium salt, its sodium salt; glycol ether diamine tetraacetic acid, its Potassium salt, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetramine hexaacetic acid, potassium salt thereof, sodium salt thereof, hydroxyethylethylenediaminetriacetic acid, potassium salt thereof, sodium salt thereof; -Diaminocyclohexa Tetraacetic acid, its potassium salt, its sodium salt; aminopolycarboxylic acids such as 1,3-diamino-2-propanoltetraacetic acid, its potassium salt, its sodium salt, etc., nitrilotriacetic acid, its potassium salt, its sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt thereof, sodium salt thereof; aminotri (methylenephosphonic acid), potassium salt thereof, sodium salt thereof; ethyleneaziminetetra (methylenephosphonic acid), potassium salt thereof, Sodium salt; diethylenetriaminepenta (methylenephosphonic acid), potassium salt thereof, sodium salt thereof; organic phosphonic acid such as hexamethylenediaminetetra (methylenephosphonic acid), potassium salt, sodium salt thereof, or 2-phosphonobutant Carboxylic acid-1,2,4, potassium salt thereof, sodium salt thereof; 2 Monophosphonobutanone tricarboxylic acid-2,3,4, potassium salt thereof, sodium salt thereof; 1-phosphonoethane tricarboxylic acid-1,2 2, phosphonoalkanetricarboxylic acids such as potassium salt and sodium salt thereof. Organic amine salts are also effective in place of the sodium and potassium salts of the chelating agents. These chelating agents are selected so that they exist stably in the plate surface protective liquid composition and do not impair the printability. The addition amount is suitably 0.001 to 1.0% by mass with respect to the plate surface protective liquid at the time of use.

A preservative, an antifoaming agent and the like can be further added to the plate surface protective liquid of the present invention. Examples of preservatives include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, 5-chloro-2-methyl-3-isothiazolone, 2-methyl-3-isothiazolone, benzoisothiazoline- 3-ones, benztriazole derivatives, amiding anidine derivatives, quaternary ammonium salts, pyridine, quinoline, guanidine and other derivatives, diazines, triazole derivatives, oxazole, oxazine derivatives, and nitrobromoalcohol-based 2-bromo-2-nitropropane -1,3-diol, 1,1-dibromo-1-nitro-2-ethanol, 1,1-dibromo-1-nitro-2-propanol omazine and the like. A preferable addition amount of the preservative is an amount that stably exerts an effect on bacteria, fungi, yeast, etc., and varies depending on the kind of the bacteria, fungi, yeast, but 0.01 to The range of 4.0% 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.
Moreover, as a defoaming agent, a compound such as a general silicon-based self-emulsifying type, an emulsifying type, or a surfactant nonionic HLB of 5 or less can be used. Silicon antifoaming agents such as dimethyl silicone are preferred. Among them, an emulsified dispersion type and a solubilized type can be used. Preferably, the range of 0.001 to 1.0% by mass in the plate surface protective solution is optimal.

  The remainder of the plate surface protective liquid used in the present invention is water. When the plate surface protective solution is prepared as a solution type or an emulsified type, it can be prepared according to a conventional method. For example, in emulsification dispersion, prepare the aqueous phase at a temperature of 40 ° C ± 5 ° C, stir at high speed, slowly drop the prepared oil phase into the aqueous phase, stir well, and then create an emulsion through a pressure-type homogenizer. Can do.

The use mode of the plate surface protective solution is not particularly limited, but it is preferable to use an automatic gum applicator or the like because uniform application is possible. The treatment with the plate surface protection liquid can be carried out immediately after the development process by anhydrous washing, or after the development process (including a washing process, washing with circulating water or a small amount of applied washing with water) or a rinsing solution containing a surfactant. It can also be done after processing.
The treatment with the plate surface protective liquid is also suitably performed using an automatic developing machine. This automatic developing machine generally consists of a developing unit and a post-processing unit, and includes a device for transporting a lithographic printing plate precursor, each processing solution tank and a spray device, while horizontally transporting the exposed lithographic printing plate precursor, Each processing liquid pumped up by a pump is sprayed from a spray nozzle to develop and post-process. In addition, a method of immersing and transporting in a processing liquid tank filled with the processing liquid by a guide roll in the liquid and developing processing, or supplying a small amount of rinsing water after development to the plate surface and rinsing the waste water A method of reusing as a diluting water for a developer stock solution is also known.
In such automatic processing, processing can be performed while each replenisher is replenished with each replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.
The lithographic printing plate treated with the plate surface protective liquid and coated with the plate surface protective layer is applied to an offset printing machine and used for printing a large number of sheets.

<Lithographic printing plate precursor>
The lithographic printing plate precursor to which the plate making method of the present invention is applied has a photosensitive recording layer on an aluminum support, and contains an organic polymer compound on the aluminum support opposite to the surface having the photosensitive recording layer. A lithographic printing plate precursor having a backcoat layer.
[Back coat layer]
The organic polymer compound contained in the backcoat layer is not particularly limited, but it is particularly preferable to use an epoxy resin, and more preferably at least one selected from resins having a rosin and a phenolic hydroxyl group. preferable. Among them, a combination of an epoxy resin and rosin is preferable, and a resin having a phenolic hydroxyl group may be contained. Furthermore, in order to improve various properties of the backcoat layer, other resins and additives may be used in combination.

(Epoxy resin)
Examples of the epoxy resin used for the back coat layer include glycidyl ether compounds obtained by the reaction of polyhydric alcohols and polyphenols with epichlorohydrin or prepolymers thereof, and polymers or copolymers of acrylic acid or glycidyl methacrylate. A polymer etc. can be mentioned.

  Specific examples of suitable compounds include propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl ether of hydrogenated bisphenol A , Hydroquinone diglycidyl ether, resorcinol diglycidyl ether, diglycidyl ether or epichlorohydrin polyadduct of bisphenol A, diglycidyl ether or epichlorohydrin polyadduct of bisphenol F, diglycidyl ether of halogenated bisphenol A Or epichlorohydrin polyadduct, diglycidyl ether of biphenyl type bisphenol or epichloro Dorin polyadducts, glycidyl ethers of novolac resins, further, methyl methacrylate / glycidyl methacrylate copolymer, methacrylic acid ethyl / glycidyl methacrylate copolymer, and the like.

  Commercially available products of the above compounds include, for example, jER1001 (molecular weight of about 900, epoxy equivalent of 450 to 500), jER1002 (molecular weight of about 1600, epoxy equivalent of 600 to 700), and jER1004 (molecular weight of about 1060) manufactured by Japan Epoxy Resins Co., Ltd. , Epoxy equivalent 875-975), jER1007 (molecular weight about 2900, epoxy equivalent 2000), jER1009 (molecular weight about 3750, epoxy equivalent 3000), jER1010 (molecular weight about 5500, epoxy equivalent 4000), jER1100L (epoxy equivalent 4000), jERYX31575 ( Epoxy equivalent 1200), Sumitomo Chemical Co., Ltd. Sumiepoxy ESCN-195XHN, ESCN-195X1, ESCN-195XF, etc. can be mentioned.

  It is preferable that the weight average molecular weight of an epoxy resin is 1000 or more in polystyrene conversion. More preferably, the weight average molecular weight is 1,000 to 500,000, still more preferably 1,000 to 200,000, and particularly preferably 1,000 to 100,000.

  The content of the epoxy resin in the backcoat layer is 50% with respect to the total mass of the backcoat layer from the viewpoint of preventing scratching and preventing slipping between the plates when laminated without sandwiching the interleaving paper. It is preferably in the range of -100% by mass, more preferably in the range of 65-99% by mass, and still more preferably in the range of 70-97.5% by mass.

(Other resins)
-Rosin-
Examples of rosins include natural rosins such as gum rosin, tall oil rosin, and wood rosin; polymerized rosins derived from the natural rosins; stabilized rosins obtained by disproportionating or hydrogenating the natural rosins and polymerized rosins; Examples thereof include unsaturated acid-modified rosin obtained by adding unsaturated carboxylic acids to natural rosin and polymerized rosin. The unsaturated acid-modified rosin includes, for example, maleic acid-modified rosin, maleic anhydride-modified rosin, fumaric acid-modified rosin, itaconic acid-modified rosin, crotonic acid-modified rosin, cinnamic acid-modified rosin, acrylic acid-modified rosin, Examples thereof include methacrylic acid-modified rosin and acid-modified polymerized rosin corresponding thereto.
Among such rosins, rosin-modified phenolic resins or rosin esters are preferably used.

Examples of the rosin ester include super ester E-720, super ester E-730-55, super ester E-650, super ester E-786-60, tamanol E-100, emulsion AM-1002, emulsion SE-50 (and above). All trade names, special rosin ester emulsion, manufactured by Arakawa Chemical Industries, Ltd.), Super Ester L, Super Ester A-18, Super Ester A-75, Super Ester A-100, Super Ester A-115, Super Ester A- 125, Superester T-125 (all trade names, special rosin esters, manufactured by Arakawa Chemical Industries, Ltd.) and the like can be preferably used.
As rosin esters, ester gum AAG, ester gum AAL, ester gum A, ester gum AAV, ester gum 105, ester gum HS, ester gum AT, ester gum H, ester gum HP, ester gum HD, Pencel A, Pencel AD, Pencel AZ, Pencel C, Pencel D-125, Pencel D-135, Pencel D-160, Pencel KK (all trade names, rosin ester resins, manufactured by Arakawa Chemical Industries, Ltd.) are also preferably used. it can.

  Examples of the rosin-modified phenolic resin include Tamanol 135, Tamanol 145, Tamanol 340, Tamanol 350, Tamanol 351, Tamanol 352, Tamanol 353, Tamanol 354, Tamanol 359, Tamanol 361, Tamanol 362, Tamanol 366, Tamanol 374, and Tamanol. 379, Tamanoru 380, Tamanoru 381, Tamanoru 384, Tamanoru 386, Tamanoru 387, Tamanoru 388, Tamanoru 392, Tamanoru 394, Tamanoru 395, Tamanoru 396, Tamanoru 405, Tamanoru 406, Tamanoru 409, Tamanoru 410, Tamanoru 414, Tamanoru 415 All of the above can be preferably used as trade names, rosin-modified phenolic resins, manufactured by Arakawa Chemical Industries, Ltd.

  Furthermore, other rosins include Longis R, Longes K-25, Longis K-80, Longes K-18 (all trade names, rosin derivatives, manufactured by Arakawa Chemical Industries, Ltd.) Pine Crystal KR-85, Pine Crystal KR-612, Pine Crystal KR-614, Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, Pine Crystal 30PX, Pine Crystal D-6011, Pine Crystal D-6154, Pine Crystal D-6240, Pine Crystal KM-1500, Pine Crystal KM-1550 (all trade names, ultra-light color rosin derivatives, manufactured by Arakawa Chemical Industries, Ltd.) and the like.

  The weight average molecular weight of the rosin used in the present invention is preferably 1000 or more in terms of polystyrene. More preferably, the weight average molecular weight is 1,000 to 500,000, still more preferably 1,000 to 200,000, and particularly preferably 1,000 to 100,000.

  The content of the rosin in the backcoat layer is 0 to 0 with respect to the total mass of the backcoat layer from the viewpoint of preventing scratches and preventing slipping between the plates when laminated without sandwiching the interleaf. The range is preferably 50% by mass, more preferably 1 to 35% by mass, and even more preferably 2.5 to 30% by mass.

-Resin having phenolic hydroxyl group-
Examples of the resin having a phenolic hydroxyl group that can be used in the present invention include a condensation polymer of phenol and formaldehyde, a condensation polymer of m-cresol and formaldehyde, a condensation polymer of p-cresol and formaldehyde, m− / Novolak resin such as polycondensation polymer of p-mixed cresol and formaldehyde, phenol and cresol (any of m-, p-, or m- / p-mixed) and formaldehyde, pyrogallol and acetone The pyrogallol resin which is a condensation polymer with can be mentioned.

Moreover, the copolymer which copolymerized the compound which has a phenolic hydroxyl group can also be used as resin which has a phenolic hydroxyl group.
Here, examples of the compound having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenolic hydroxyl group.

  The weight average molecular weight of the resin having a phenolic hydroxyl group is preferably 1000 or more in terms of polystyrene from the viewpoint of film properties. More preferably, the weight average molecular weight is 1,000 to 500,000, still more preferably 1,000 to 200,000, and particularly preferably 1,000 to 100,000.

  The content of the resin having a phenolic hydroxyl group in the back coat layer is 0.1 to 0.1% relative to the total mass of the back coat layer from the viewpoint of film properties and adhesion resistance to the outermost surface on the photosensitive recording layer side. The range is preferably 90% by mass, more preferably 0.1 to 50% by mass, and still more preferably 0.5 to 30% by mass.

(Other ingredients)
Furthermore, for the purpose of improving the film properties, the back coat layer may be added with an organic or inorganic polymer compound, or may have flexibility or adjust slip properties, and may be a plasticizer or a surfactant. Other additives can be added as necessary.

  Preferred polymer compounds include, for example, polybutene, polybutadiene, polyamide, unsaturated copolymerized polyester resin, polyurethane, polyurea, polyimide, polysiloxane, polycarbonate, chlorinated polyethylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, acrylic resin These copolymer resins, hydroxycellulose, polyvinyl alcohol, cellulose acetate, carboxymethylcellulose and the like are suitable.

  As these polymer compounds, those having a weight average molecular weight of 500 or more in terms of polystyrene are preferably used. More preferably, the weight average molecular weight is 1,000 to 500,000, still more preferably 1,000 to 200,000, and particularly preferably 1,000 to 100,000.

Preferred plasticizers used for the backcoat layer include, for example, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate, etc. Phthalates, dimethyl glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, glycol esters such as triethylene glycol dicaprylate, tricresyl phosphate, triphenyl Phosphate esters such as phosphate, diisobutyl adipate, dioctyl adipate Dimethyl sebacate, dibutyl sebacate, dioctyl azelate, aliphatic, such as dibutyl maleate dibasic acid esters, polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, and butyl laurate is effective.
These plasticizers are added as long as the back coat layer is not sticky.

Preferred examples of the surfactant used in the back coat layer in the present invention include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers 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 partial ester , Polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, polyoxyethylenated castor oil, polyoxyethylene Nonionic surfactants such as glycerin fatty acid partial esters, fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid esters, trialkylamine oxides, fatty acids Salts, abietates, hydroxyalkanesulfonates, alkanesulfonates, dialkylsulfosuccinates, linear alkylbenzenesulfonates, branched alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkylphenoxypolyoxyethylenepropyl Sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide dinatri Salts, petroleum sulfonates, sulfated beef oil, sulfates of fatty acid alkyl esters, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates , Polyoxyethylene styryl phenyl ether sulfate ester salts, alkyl phosphate ester salts, polyoxyethylene alkyl ether phosphate ester salts, polyoxyethylene alkyl phenyl ether phosphate ester salts, partially saponified products of styrene / maleic anhydride copolymer , Partially saponified products of olefin / maleic anhydride copolymer, naphthalenesulfonate formalin condensates, alkylamine salts, quaternary ammonium salts , Cationic surfactants such as polyoxyethylene alkylamine salts and polyethylene polyamine derivatives, and amphoteric surfactants such as carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfates, and 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 perfluoroalkyl amine 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, 0.001-10 mass% with respect to the total mass of a backcoat layer, More preferably, the range of 0.001-5 mass% Is added.

  The backcoat layer in the present invention further includes an o-naphthoquinone diazide compound, a photosensitive azide compound, a photopolymerizable composition containing an unsaturated double bond-containing monomer as a main component, and a photocrosslinking containing cinnamic acid or a dimethylmaleimide group. Chemical compounds and diazo resins obtained by condensing diazonium salt monomers and aromatic diazonium salts with reactive carbonyl group-containing organic condensing agents (especially aldehydes or acetals such as formaldehyde and acetaldehyde) in an acidic medium. It can be added for improvement. Of these, o-naphthoquinonediazide compounds known as positive photosensitive compounds are preferably used.

The back coat layer can be provided by thermocompression bonding of a film, a melt lamination method, or a coating method, but coating from a solution is more preferable for efficiently providing a thin layer.
Therefore, the resin used for the back coat layer is preferably non-crystalline and easily soluble in various industrial organic solvents.
Solvents used in forming the backcoat layer include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, acetylacetone, cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethyleneglycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, lactic acid Examples include methyl and ethyl lactate.
These solvents can be used alone or in combination. The concentration of the solid content in the backcoat layer forming coating solution is suitably 0.5 to 50% by mass.

In the present invention, the coating amount of the backcoat layer mainly affects the static friction coefficient and the generation of scratches, and it is desirable to select appropriately according to the application. If the coating amount is too small, the effect of generating a static friction coefficient and scratches on the backcoat layer becomes insufficient. On the other hand, when the amount is too large, the adhesion of the membrane to the support deteriorates and is not preferred because it peels off during handling.
The coverage of the backcoat layer, the mass after drying is preferably in the range of 0.01 to 10 g / m ^2, more preferably in the range of 0.05~7g / m ^2, of 0.1-5 g / m ² A range is more preferred.

In addition, when the planographic printing plate precursor is laminated without interposing the interleaving paper, it is preferable to control the smoothness between the plates.
The sliding property between the plate materials can be determined by using the coefficient of static friction of the backcoat layer as an index. Specifically, in the planographic printing plate precursor used in the present invention, the static friction coefficient of the backcoat layer with respect to the outermost surface on the photosensitive recording layer side is preferably in the range of 0.35 to 1.00, 0.40 More preferably, it is in the range of -1.00. When the static friction coefficient is within this range, no slip occurs between the plate materials, and a stable laminate can be formed.
Moreover, since the friction between the plate materials can be reduced when the static friction coefficient is in the above range, the generation of scratches can be further suppressed.

(Photosensitive recording layer)
A lithographic printing plate precursor employing the plate making method of the present invention has a photosensitive recording layer on the surface of the support opposite to the surface having the backcoat layer.
The photosensitive recording layer may be a positive type or a negative type, and the mechanism of image formation is not particularly limited. Examples of the photosensitive recording layer include a conventional positive type, a conventional negative type, a photopolymer type (photopolymerization type), a thermal positive type, and a thermal negative type (thermal polymerization type and acid crosslinking type). The term "conventional" as used herein refers to a conventional lithographic printing plate precursor that performs imagewise exposure through a transparent positive image or a transparent negative image. Hereinafter, these photosensitive recording layers will be briefly described.

(Conventional positive type)
A preferable example of a conventional positive photosensitive resin composition is a composition containing an o-quinonediazide compound and an alkali-soluble polymer compound. Examples of o-quinonediazide compounds include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, and US Pat. No. 3,635,709. There are esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol acetone resin as described. Examples of the alkali-soluble polymer compound include phenol / formaldehyde resin, cresol / formaldehyde resin, phenol / cresol / formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, JP-A-7- Examples thereof include carboxy group-containing polymers described in Japanese Patent No. 36184. Further, acrylic resins containing phenolic hydroxy groups as described in JP-A-51-34711, acrylic resins having sulfonamide groups as described in JP-A-2-866, and urethane Various alkali-soluble polymer compounds such as resins can also be used. Further, the photosensitive resin composition includes compounds such as sensitivity modifiers, printing agents, dyes and the like disclosed in JP-A-7-92660 [0024] to [0027] and those disclosed in the same publication [0031]. It is preferable to add a surfactant for improving the coatability.
A conventional positive photosensitive lithographic printing plate precursor provided with a photosensitive composition containing an o-quinonediazide compound and an alkali-soluble polymer compound on a support is imagewise exposed using ultraviolet rays, and then an alkaline developer. Developed with Examples of such developers include alkali metal silicate aqueous solutions described in Japanese Patent Publication No. 57-7427 and Japanese Patent No. 3086354, and developers containing non-reducing sugars and bases as described in JP-A-8-305039. A preferred example is given.

(Conventional negative type)
Examples of conventional negative photosensitive resin compositions include those containing a diazo resin and an alkali-soluble or swellable polymer compound (binder).
Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde. Further, for example, a condensate of p-diazophenylamines and formaldehyde and a hexafluorophosphate or An organic solvent-soluble diazo resin inorganic salt that is a reaction product with tetrafluoroborate is exemplified. In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable. Suitable binders include copolymers containing acrylic acid, methacrylic acid, crotonic acid or maleic acid as essential components, for example, 2-hydroxyethyl (meta) as described in JP-A-50-118802. ) Acrylate, (meth) acrylonitrile, multi-component copolymers of monomers such as (meth) acrylic acid, alkyl acrylate, (meth) acrylonitrile, and unsaturated as described in JP-A-56-4144 Mention may be made of multi-component copolymers composed of carboxylic acids. Further, the photosensitive resin composition is a plasticizer for imparting the flexibility and wear resistance of the baking agent, dye, and coating film disclosed in JP-A-7-281425 [0014] to [0015]. It is preferable to add a compound such as a development accelerator and a surfactant for improving the coating property.

As a lower layer of the above-mentioned conventional type positive type or negative type photosensitive layer, a polymer compound having a component having an acid group and a component having an onium group described in JP-A-2000-105462 is used. It is preferable to provide an intermediate layer to be contained.
The photosensitive lithographic printing plate using the conventional negative photosensitive resin composition thus prepared is imagewise exposed using ultraviolet rays and then developed with a developer. As a developer for such a conventional negative photosensitive resin composition, an alkali agent, an organic solvent, a surfactant, a water softener, a reducing agent, an organic carboxylic acid, an inorganic salt, an antifoaming agent, and further as necessary. Aqueous solutions containing various additives known in the art are used. Particularly preferable examples include those described in JP-B-56-42860, JP-B-58-54341, JP-B-2-37579, JP-A-62-200154, and JP-A-64-44445. Examples include a developer.

(Photopolymer type)
(Photosensitive layer)
A photopolymer type photopolymerizable photosensitive composition (hereinafter referred to as “photopolymerizable composition”) is an addition-polymerizable ethylenically unsaturated bond-containing compound (hereinafter simply referred to as “ethylenically unsaturated bond-containing compound”). And a photopolymerization initiator and a polymer binder as essential components, and if necessary, various compounds such as a colorant, a plasticizer, a thermal polymerization inhibitor and the like.
The ethylenically unsaturated bond-containing compound contained in the photopolymerizable composition is such that, when the photopolymerizable composition is irradiated with actinic rays, it undergoes addition polymerization by the action of the photopolymerization initiator, crosslinks and cures. It is a compound having an ethylenically unsaturated bond. The ethylenically unsaturated bond-containing compound can be arbitrarily selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more, such as monomers, prepolymers (ie, dimers). Trimers and oligomers), mixtures thereof, and copolymers thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic polyhydric compounds. And amides with a polyvalent amine compound. Urethane addition polymerizable compounds are also suitable.

As the initiator contained in the photopolymerizable composition, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators are appropriately selected and used depending on the wavelength of the light source used. For example, the initiation system shown in JP-A-2001-22079 [0021] to [0023] is preferred. The polymer binder contained in the photopolymerizable composition not only functions as a film-forming agent for the photopolymerizable composition, but also needs to dissolve the photosensitive layer in an alkali developer. An organic high molecular weight polymer that is swellable is used. As the polymer, those shown in the publications [0036] to [0063] are useful. In addition, it is also preferable to add an additive (for example, a surfactant for improving the coating property) shown in the publications [0079] to [0088] to the photopolymerizable composition.
Further, it is preferable to provide an oxygen-blocking protective layer on the photosensitive layer in order to prevent the oxygen polymerization inhibiting action. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol or a copolymer thereof. Furthermore, it is also preferable to provide an intermediate layer or an adhesive layer as shown in JP-A-2001-228608 [0124] to [0165] as the lower layer of the photopolymer type photosensitive layer.
A photosensitive lithographic printing plate using such a photopolymer type photopolymerizable photosensitive composition is imagewise exposed using ultraviolet rays such as a high-pressure mercury lamp, an argon laser and an ultraviolet laser, and then developed with a developer. Preferred developers include alkali agents, organic solvents, surfactants, hard water softeners, reducing agents, organic carboxylic acids, inorganic salts, antifoaming agents, and various other types known in the art as necessary. An aqueous solution containing an additive is used. Particularly preferred examples include developers described in JP-B-58-54341, JP-A-8-248643, JP-A-2002-91015, and JP-A-8-171214.

(Thermal positive type)
(Thermosensitive layer)
The thermal positive type heat-sensitive layer contains an alkali-soluble polymer compound and a photothermal conversion substance. This alkali-soluble polymer compound includes a homopolymer containing an acidic group in the polymer, a copolymer thereof, and a mixture thereof. In particular, an acidic group such as the following (1) or (2) is included. It is preferable from the viewpoint of solubility in an alkali developer: (1) a phenolic hydroxy group (—Ar—OH), (2) a sulfonamide group (—SO ₂ NH—R). In particular, it is preferable to have a phenolic hydroxy group from the viewpoint of excellent image forming property by exposure with an infrared laser or the like, for example, phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m− / p−. Preferable examples include mixed cresol formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed formaldehyde resin and the like, and pyrogallol acetone resin. More specifically, the polymers shown in [0023] to [0042] of JP-A No. 2001-305722 are preferably used.

The photothermal conversion substance converts exposure energy into heat and can efficiently cancel the interaction of the exposed area of the heat sensitive layer. From the viewpoint of recording sensitivity, a pigment or dye having a light absorption region in the infrared region with a wavelength of 700 to 1200 nm is preferable. As a dye. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes (for example, A dye such as a nickel thiolate complex) can be used. Among these, cyanine dyes are preferable, and examples thereof include cyanine dyes represented by general formula (I) in JP-A No. 2001-305722. In the composition of the thermal positive type, it is preferable to add a sensitivity control agent, a printing agent, a compound such as a dye similar to those described for the conventional positive type, and a surfactant for improving the coating property. Specifically, the compounds shown in [0053] to [0059] of JP-A No. 2001-305722 are preferable.
The thermal positive type heat-sensitive layer may be a single layer or a two-layer structure as described in JP-A-11-218914.
An undercoat layer is preferably provided between the thermal positive type heat-sensitive layer and the support. Examples of components contained in the undercoat layer include various organic compounds disclosed in JP-A-2001-305722, [0068] and [0081].
A thermal positive type heat-sensitive lithographic printing plate precursor provided with a heat-sensitive composition containing these alkali-soluble polymer compound and a photothermal conversion substance on a support is imagewise exposed using an infrared laser, and then an alkaline developer. Developed with Examples of such a developer include Japanese Patent Publication No. 57-7427, Japanese Patent No. 3086354, Japanese Patent Application Laid-Open No. 11-216962, Japanese Patent Application Laid-Open No. 2001-51406, Japanese Patent Application Laid-Open No. 2001-174981, and Japanese Patent Application Laid-Open No. 2002-72501. As a preferred example, a developing solution described in Japanese Patent Publication No. JP-A No. 2004-259561 can be given.

(Thermal negative type)
(Thermosensitive layer)
The thermal negative-type heat-sensitive layer is a negative-type heat-sensitive layer in which the infrared laser irradiation part is cured to form an image part.
As one of such thermal negative type heat-sensitive layers, a polymerization type layer is preferably exemplified. The polymerization layer comprises (A) an infrared absorber, (B) a radical generator (radical polymerization initiator), a curing reaction caused by the generated radical (C) a radical polymerizable compound, and (D) a binder. Containing polymer.
In the polymerization layer, the infrared rays absorbed by the infrared absorber are converted into heat, and the generated heat decomposes radical polymerization initiators such as onium salts to generate radicals. The radically polymerizable compound is selected from compounds having a terminal ethylenically unsaturated bond, and a polymerization reaction is caused in a chain by the generated radicals and is cured. (A) As an infrared absorber, for example, the above-mentioned photothermal conversion substance contained in the above-mentioned thermal positive type thermosensitive layer can be mentioned. [0017] to [0019] may be mentioned. Examples of the radical generator (B) include onium salts. Specific examples of onium salts that can be suitably used are described in paragraphs [0030] to [0033] of JP-A No. 2001-133969. Things can be mentioned. (C) The radically polymerizable compound is selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more. (D) It is preferable to use a linear organic polymer as the binder polymer, and a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected. Of these, a (meth) acrylic resin having a benzyl group or an allyl group and a carboxy group in the side chain is particularly preferable because of its excellent balance of film strength, sensitivity, and developability. With respect to (C) the radical polymerizable compound and (D) the binder polymer, those described in detail in the publications [0036] to [0060] can be used. As other additives, it is also preferable to add an additive (for example, a surfactant for improving coating properties) shown in the publications [0061] to [0068].

In addition to the polymerization type, an acid-crosslinking type layer is preferably used as one of the thermal negative type heat-sensitive layers. The acid cross-linking layer comprises (E) a compound that generates an acid by light or heat (hereinafter referred to as “acid generator”) and (F) a compound that cross-links by the generated acid (hereinafter referred to as “cross-linking agent”). And (G) an alkali-soluble polymer compound that can react with a crosslinking agent in the presence of an acid. In order to efficiently use the energy of the infrared laser, (A) an infrared absorber is blended in the acid crosslinking layer. Examples of the acid generator (E) include compounds capable of generating an acid upon thermal decomposition, such as a photoinitiator for photopolymerization, a photochromic agent for dyes, and an acid generator used for a microresist. . (F) The crosslinking agent includes (i) an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group, (ii) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, Or (iii) an epoxy compound is mentioned. (G) Examples of the alkali-soluble polymer compound include novolak resins and polymers having a hydroxyaryl group in the side chain.
The thermal negative lithographic printing plate precursor provided with the polymerization type and acid cross-linked thermal negative type thermosensitive layer on the support is imagewise exposed using an infrared laser and then developed with an alkaline developer. Examples of such a developer include Japanese Patent Publication No. 57-7427, Japanese Patent Application Laid-Open No. 2001-133969 [0119] to [0123], Japanese Patent Application No. 2002-47985, Japanese Patent Application No. 2002-59297, And a developer described in U.S. Pat. No. 5,766,826 is a particularly preferable example.

(Support)
An aluminum plate is used as a support for the lithographic printing plate precursor on which the photosensitive recording layer is provided. The aluminum plate is a plate-like body such as pure aluminum or an aluminum alloy containing aluminum as a main component and containing a small amount of foreign atoms. Such heteroatoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium, and the like. As the alloy composition, a foreign atom content of 10% by mass or less is appropriate. The preferred aluminum is pure aluminum, but completely pure aluminum is difficult to produce by refining technology, so it is preferable that it contains as few foreign atoms as possible. Moreover, it can be said that it is a raw material which can be used for this invention if it is an aluminum alloy of the foreign atom content rate of the extent mentioned above. The composition of the aluminum plate is not particularly limited, and conventionally known and publicly available materials can be used as appropriate. Preferred materials include JIS A 1050, 1100, 1200, 3003, 3103, and 3005. The thickness of the aluminum plate used in the present invention is suitably about 0.1 mm to 0.6 mm. Prior to roughening the aluminum plate, a degreasing treatment for removing the rolling oil on the surface, for example, with a surfactant or an alkaline aqueous solution is performed as necessary.
Next, roughening treatment, anodic oxidation treatment, hydrophilic treatment and the like are performed in an appropriate combination. For example, there is a support treatment method as disclosed in JP-A-2001-356494.
A lithographic printing plate precursor is obtained by coating a photosensitive recording layer on such a support, but an intermediate layer may be provided before coating the photosensitive recording layer. A material containing an organic polymer compound is often used as such an intermediate layer, for example, one disclosed in JP-A-2001-356494.

In particular, the problem that the surface of the lithographic printing plate precursor is scratched is a negative type that causes stains on the printed matter due to curing of the scratched part, and the effect of the backcoat layer appears more remarkably. Therefore, the photosensitive recording layer of the lithographic printing plate precursor particularly suitable for application of the plate making method of the present invention is a polymerizable negative photosensitive layer.
Hereinafter, a polymerizable negative photosensitive layer suitable as a photosensitive recording layer of a lithographic printing plate precursor to which the method of the present invention is applied will be described in detail.

(Polymerizable negative photosensitive layer)
The polymerizable negative photosensitive layer (hereinafter sometimes simply referred to as “photosensitive layer”) contains a sensitizing dye, a polymerization initiator, a polymerizable compound, and a binder polymer, and, if necessary, a colorant. And other optional components.

Since the polymerizable negative photosensitive layer is sensitive to a laser corresponding to a sensitizing dye, it can be exposed to various lasers useful for CTP. For example, in the case of using an infrared absorber as a sensitizing dye, the infrared absorber contained in the polymerizable negative photosensitive layer is highly sensitive to the irradiation (exposure) of an infrared laser and is in an electronically excited state. Electron transfer, energy transfer, heat generation (photothermal conversion function), and the like related to the electronically excited state act on the polymerization initiator coexisting in the photosensitive layer to cause a chemical change in the polymerization initiator to generate radicals.
In this case, the radical generation mechanism is as follows: 1. Heat generated by the photothermal conversion function of the infrared absorber thermally decomposes a polymerization initiator (for example, sulfonium salt) described later to generate radicals. 2. Excited electrons generated by the infrared absorber move to a polymerization initiator (for example, an active halogen compound) to cause radicals. For example, radicals are generated by electron transfer from a polymerization initiator (for example, a borate compound) to an excited infrared absorber. Then, the polymerizable compound causes a polymerization reaction by the generated radical, and the exposed portion is cured to become an image portion.

  The lithographic printing plate precursor of the above embodiment is particularly suitable for plate making directly drawn with an infrared laser beam having a wavelength of 750 nm to 1400 nm because the polymerizable negative photosensitive layer contains an infrared absorber as a sensitizing dye. In addition, it can exhibit high image-forming properties as compared with conventional lithographic printing plate precursors.

In the plate-making method of the present invention, an infrared absorber, a polymerization initiator (a compound that generates radicals by light or heat), a monomer having two or more phenyl groups substituted with vinyl groups in the molecule, and vinyl groups are substituted. A polymerizable negative photosensitive layer containing a polymer having a phenyl group in the side chain is a preferred embodiment from the viewpoint of high sensitivity.
Below, each component which comprises a polymerizable negative photosensitive layer is demonstrated.

(Sensitizing dye)
From the viewpoint of sensitivity, the photosensitive layer contains a sensitizing dye that absorbs light having a predetermined wavelength that matches the exposure wavelength in laser exposure.
The exposure of the wavelength that can be absorbed by the sensitizing dye accelerates the radical generation reaction of the polymerization initiator described later and the polymerization reaction of the polymerizable compound thereby. Examples of such a sensitizing dye include a known spectral sensitizing dye or dye, or a dye or pigment that absorbs light and interacts with a photopolymerization initiator. This sensitizing dye becomes a highly sensitive electron excited state by laser exposure at a wavelength suitable for the sensitizing dye, and electron transfer, energy transfer, etc. related to the electron excited state act on the polymerization initiator described later, and the polymerization initiator has a high level. It is useful for generating radicals by causing chemical changes with sensitivity.

  Depending on the wavelength of light absorbed by the sensitizing dye, the photosensitive layer in the present invention can be sensitive to various wavelengths from ultraviolet rays to visible rays and infrared rays. For example, when an infrared absorber is used as the sensitizing dye, it is sensitive to infrared light having a wavelength of 760 nm to 1200 nm. Further, by using a dye having a maximum absorption wavelength from 350 nm to 450 nm, it is sensitive to blue to purple visible light.

  Preferred spectral sensitizing dyes or dyes as sensitizing dyes include polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines ( For example, thiacarbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), Phthalocyanines (eg, phthalocyanine, metal phthalocyanine), porphyrins (eg, tetraphenylporphyrin, central metal-substituted porphyrin), chlorophylls (eg, chlorophyll, chlorophyllin, Heart metal-substituted chlorophyll), metal complexes, anthraquinones (for example, anthraquinone), squalium (for example, squalium), and the like. In detail, the compounds described herein can be appropriately selected and used as sensitizing dyes.

In particular, the photosensitive layer preferably contains an infrared absorber described in detail below as a sensitizing dye.
Infrared absorbers are in an electronically excited state with high sensitivity to infrared laser irradiation (exposure), and heat energy is generated by the photothermal conversion function in addition to the electron transfer and energy transfer related to the previous electron excited state. It is useful for causing a chemical change with high sensitivity by a polymerization initiator.
As an infrared absorber that is a particularly preferable sensitizing dye, a dye or pigment having an absorption maximum at a wavelength of 750 nm to 1400 nm is preferably exemplified.

As the dye, commercially available dyes and known dyes described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, etc. Is mentioned.
Examples of preferable dyes include cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, 58-181690, JP-A-58-194595, etc., methine dyes, JP-A-58-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59- No. 73996, JP-A-60-52940, JP-A-60-63744 and the like, Naphthoquinone dyes described in JP-A-58-112792, etc., British Patent 434,875 And cyanine dyes.

Also, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 The pentamethine thiopyrylium salts described above and the pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 are also preferably used. . Moreover, as another example preferable as a dye, the near-infrared absorptive dye described as the formula (I) and (II) in US Patent 4,756,993 can be mentioned.
Other preferable examples of infrared absorbing dyes include specific indolenine cyanine dyes described in JP-A-2002-278057 as exemplified below.

  Particularly preferred among these dyes are cyanine dyes, squarylium dyes, pyrylium salts, nickel thiolate complexes, and indolenine cyanine dyes. Further, cyanine dyes and indolenine cyanine dyes are preferred, and particularly preferred examples include cyanine dyes represented by the following general formula (a).

In formula (a), X ¹ represents a hydrogen atom, a halogen atom, -NPh _2, X ² -L ¹ or a group shown below. Here, X ² represents an oxygen atom, a nitrogen atom, or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms, an aromatic ring having a hetero atom, or 1 to 1 carbon atom containing a hetero atom. 12 hydrocarbon groups are shown. In addition, a hetero atom here shows N, S, O, a halogen atom, and Se.
In the group shown below, X _a ^- is Z _a which will be described below ^- has the same definition as, R ^a represents a hydrogen atom, an alkyl group, an aryl group, a substituted or unsubstituted amino group, substituted or unsubstituted amino group and a halogen atom Represents.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of a photosensitive layer coating solution, R ¹ and R ² are preferably a hydrocarbon group having two or more carbon atoms, bonded to each other and R ¹ and R ^2, 5-membered It is particularly preferable that a ring or a 6-membered ring is formed.

Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred substituents include hydrocarbon groups having 12 or less carbon atoms, halogen atoms, and alkoxy groups having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different and each represents a sulfur atom or a dialkylmethylene group having 12 or less carbon atoms. R ³ and R ⁴ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include alkoxy groups having 12 or less carbon atoms, carboxyl groups, and sulfo groups. R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the availability of raw materials, a hydrogen atom is preferred. Z _a ^- represents a counter anion. However, when the cyanine dye represented by formula (a) has an anionic substituent in the structure thereof, Z _a is does not require charge neutralization ^- is not necessary. Preferred Z _a ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably perchloric acid, in view of the storage stability of the coating solution for forming a photosensitive layer. Ions, hexafluorophosphate ions, and aryl sulfonate ions.

Specific examples of the cyanine dye represented by the general formula (a) that can be suitably used include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057 described above.
However, a counter ion that does not contain a halogen ion is particularly preferable.

  Examples of pigments include commercially available pigment and color index (CI) manuals, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “Printing” The pigments described in "Ink Technology", published by CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  These pigments may be used without surface treatment, or may be used after surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (eg, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The above-mentioned surface treatment methods are described in “Characteristics and Applications of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm. Within this preferred particle size range, excellent dispersion stability of the pigment in the photosensitive layer can be obtained, and a uniform photosensitive layer can be obtained.

  As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).

  When these infrared absorbers are used in the photosensitive layer according to the present invention, they may be added to the same layer as other components, or another layer may be provided and added thereto.

  The addition amount of these sensitizing dyes, preferably infrared absorbers, is 0.01 to 50% by mass with respect to the total solid content constituting the photosensitive layer from the viewpoint of uniformity in the photosensitive layer and durability of the photosensitive layer. It is preferably in the range of 0.1 to 10% by mass, particularly preferably 0.5 to 10% by mass when a dye is used as a sensitizing dye, and particularly when a pigment is used. Preferably it can add in the ratio of 0.1-10 mass%.

(Polymerization initiator)
The polymerization initiator has a function of initiating and advancing a curing reaction of the polymerizable compound described later, and accepts excited electrons of a thermal decomposition type radical generator that decomposes by heat to generate radicals and an infrared absorber. By applying energy (for example, heat or light) such as an electron transfer type radical generator that generates radicals or an electron transfer type radical generator that generates electrons by transferring electrons to an excited infrared absorber. Any compound that generates radicals may be used. For example, onium salts, active halogen compounds, oxime ester compounds, borate compounds and the like can be mentioned. These may be used in combination. In the present invention, an onium salt is preferable, and a sulfonium salt is particularly preferable.
Examples of the sulfonium salt polymerization initiator suitably used include onium salts represented by the following general formula (I).

In general formula (I), R ¹¹ , R ¹² and R ¹³ may be the same or different and each represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferable substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or an aryloxy group having 12 or less carbon atoms. (Z ¹¹ ) ⁻ represents an organic or inorganic counter ion, for example, selected from the group consisting of halogen ions, perchlorate ions, tetrafluoroborate ions, hexafluorophosphate ions, carboxylate ions, and sulfonate ions. Those having a counter ion or the counter ion in the structure are preferable, and preferably a perchlorate ion, a hexafluorophosphate ion, a carboxylate ion, an aryl sulfonate ion, or the counter ion in the structure. .

  Specific examples ([OS-1] to [OS-13]) of the onium salt represented by the general formula (I) are shown below, but are not limited thereto.

  In addition to the above, specific aromatic sulfonium salts described in JP-A Nos. 2002-148790, 2002-148790, 2002-350207, and 2002-6482 are also preferably used.

  In addition to the sulfonium salt polymerization initiator, other polymerization initiators (other radical generators) can be used. Other radical generators include onium salts other than sulfonium salts, triazine compounds having a trihalomethyl group, peroxides, azo polymerization initiators, azide compounds, quinonediazides, active halogen compounds, oxime ester compounds, triaryls. Examples thereof include monoalkyl borate compounds. Among them, onium salts are preferable because of their high sensitivity. Moreover, these polymerization initiators (radical generators) can be used in combination with the sulfonium salt polymerization initiator as an essential component.

Other onium salts that can be suitably used include iodonium salts and diazonium salts. In the present invention, these onium salts function not as acid generators but as radical polymerization initiators.
Other onium salts in the present invention include onium salts represented by the following general formulas (II) and (III).

In general formula (II), Ar ²¹ and Ar ²² each independently represent an aryl group having 20 or less carbon atoms, which may have a substituent. Preferred substituents when this aryl group has a substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a carbon atom having 12 or less carbon atoms. An aryloxy group is mentioned. (Z ²¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

In the general formula (III), Ar ³¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred examples of the substituent include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms, and 12 or less carbon atoms. Examples thereof include an alkylamino group, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, or a diarylamino group having 12 or less carbon atoms. (Z ³¹ ) ⁻ represents a counter ion having the same meaning as (Z ¹¹ ) ⁻ .

  In the present invention, an onium salt represented by the general formula (II) ([OI-1] to [OI-11]) and an onium salt represented by the general formula (III) ([ Specific examples of ON-1] to [ON-5] are given below, but are not limited thereto.

  Specific examples of onium salts that can be suitably used as a polymerization initiator (radical generator) include those described in JP-A No. 2001-133696.

  As the polymerization initiator, an organic boron salt or a trihaloalkyl-substituted compound is preferably used. More preferably, an organic boron salt and a trihaloalkyl-substituted compound are used in combination. A combination of an organic boron salt and an onium salt is also preferably used.

  The organoboron anion constituting the organoboron salt is represented by the following general formula (1).

In the general formula (1), R ¹¹ , R ¹² , R ^13, and R ¹⁴ may be the same or different, and may be an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, or a cycloalkyl group. Represents a heterocyclic group. Of these, it is particularly preferred that one of R ¹¹ , R ¹² , R ¹³ and R ¹⁴ is an alkyl group and the other substituent is an aryl group.

The above-mentioned organoboron anion is present simultaneously with the cation forming a salt with the anion. Examples of the cation in this case include alkali metal ions, onium ions, and cationic sensitizing dyes.
Examples of the onium ions include ammonium ions, sulfonium ions, iodonium ions, and phosphonium ions.
When using a salt of an organic boron anion and an alkali metal ion or onium ion as the organic boron salt, adding a sensitizing dye separately to impart photosensitivity in the wavelength range of light absorbed by the dye. Is done. Further, when a salt having an organic boron anion as a counter anion of a cationic sensitizing dye is used as the organic boron salt, photosensitivity is imparted according to the absorption wavelength of the cationic sensitizing dye. However, in the latter case, it is preferable to further contain a salt of an alkali metal ion or onium ion and an organic boron anion.

The organic boron salt is a salt containing an organic boron anion represented by the general formula (1), and alkali metal ions and onium ions are preferably used as cations forming the salt. Particularly preferred examples are salts of organic boron anions and onium ions, specifically, ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and phosphonium salts such as triarylalkylphosphonium salts. Can be mentioned.
Specific examples (BC-1) to (BC-6) of particularly preferred organic boron salts are shown below.

  Specifically, the trihaloalkyl-substituted compound is a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. As a preferable example, the trihaloalkyl-substituted compound has a nitrogen-containing complex. Examples of the compound bonded to the ring group include s-triazine derivatives and oxadiazole derivatives, or trihaloalkylsulfonyl compounds in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocycle via a sulfonyl group. It is done.

  Particularly preferred specific examples (T-1) to (T-15) of compounds in which a trihaloalkyl group is bonded to a nitrogen-containing heterocyclic group, and particularly preferred specific examples (BS-1) to (BS-) of trihaloalkylsulfonyl compounds. 10) is shown below.

  An organic peroxide can also be used as a polymerization initiator. Examples of the organic peroxide include cumene hydroperoxide, tert-butyl hydroperoxide, dichloroperoxide, di-tert-butyl peroxide, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, and compounds having the structure shown below. Is mentioned.

  The polymerization initiator (radical generator) preferably has a maximum absorption wavelength of 400 nm or less, and more preferably 360 nm or less. By making the absorption wavelength in the ultraviolet region in this way, the lithographic printing plate precursor can be handled under white light.

  The total content of the polymerization initiator is from 0.1 to 50% by mass, preferably from 0.5 to 30%, based on the total solid content constituting the photosensitive layer, from the viewpoint of sensitivity and generation of stains in the non-image area during printing. % By mass, particularly preferably 1 to 20% by mass.

As a polymerization initiator in this invention, only 1 type may be used and 2 or more types may be used together. When two or more polymerization initiators are used in combination, for example, a plurality of suitably used sulfonium salt polymerization initiators may be used, or a sulfonium salt polymerization initiator and another polymerization initiator may be used in combination. Also good.
When the sulfonium salt polymerization initiator and another polymerization initiator are used in combination, the content ratio (mass ratio) is preferably 100/1 to 100/50, more preferably 100/5 to 100/25.
Moreover, a polymerization initiator may be added to the same layer as other components, or another layer may be provided and added thereto.

  When a highly sensitive sulfonium salt polymerization initiator, which is preferable as a polymerization initiator, is used for the photosensitive layer, the radical polymerization reaction proceeds effectively, and the strength of the formed image area becomes very high. Therefore, combined with the high oxygen blocking function of the protective layer described later, a lithographic printing plate having high image area strength can be produced, and as a result, printing durability is further improved. In addition, since the sulfonium salt polymerization initiator itself is excellent in stability over time, even when the produced lithographic printing plate precursor is stored, the occurrence of an undesirable polymerization reaction is effectively suppressed. Will also have.

(Polymerizable compound)
The polymerizable compound is an addition polymerizable compound having at least one ethylenically unsaturated double bond, and is selected from compounds having at least one ethylenically unsaturated bond, preferably two or more. Such a compound group is widely known in the industrial field, and can be used without any particular limitation in the present invention. These have chemical forms such as monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), and esters and amides thereof. In this case, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound, or an amide of an unsaturated carboxylic acid and an aliphatic polyvalent amine compound is used. In addition, an addition reaction product of an unsaturated carboxylic acid ester or amide having a nucleophilic substituent such as a hydroxyl group, amino group or mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, a halogen group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable. As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.

  Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol. Diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate , Tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3-methacryloxy- 2-hydroxypro ) Phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.
Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.
Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

  Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240, JP-A-59-5241. Those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also preferably used. Furthermore, the ester monomers described above can also be used as a mixture.

  Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

  In addition, urethane-based addition polymerizable compounds produced by using an addition reaction of isocyanate and hydroxyl group are also suitable, and specific examples thereof include, for example, one molecule described in JP-B-48-41708. A vinyl urethane containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxyl group represented by the following general formula (IV) to a polyisocyanate compound having two or more isocyanate groups. Compounds and the like.

CH ₂ ═C (R ^a ) COOCH ₂ CH (R ^b ) OH... General formula (IV)
(However, R ^a and R ^b represent H or CH _3. )

  Also, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, JP-B-58-49860, JP-B-56-17654, Urethane compounds having an ethylene oxide skeleton described in JP-B-62-39417 and JP-B-62-39418 are also suitable. Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238, It is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

  Other examples include polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191, JP-B-52-30490, and JP-A-52-30490. Mention may be made of polyfunctional acrylates and methacrylates such as reacted epoxy acrylates. Further, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337 and JP-B-1-40336, vinylphosphonic acid compounds described in JP-A-2-25493, and the like can also be mentioned. . In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Journal of Japan Adhesion Association vol. 20, no. 7, pages 300 to 308 (1984), which are introduced as photocurable monomers and oligomers, can also be used.

In the present invention, as the polymerizable compound, a monomer having two or more phenyl groups substituted with vinyl groups (hereinafter referred to as a specific monomer as appropriate) can also be preferably used.
In order to effectively perform crosslinking by recombination of styryl radicals generated by radicals generated from the above-described polymerization initiator (radical generator), the inclusion of this component makes it highly sensitive and does not require heat treatment. Type photosensitive layer.
The specific monomer in the present invention is typically a compound represented by the following general formula (3).

In General Formula (3), Z ² represents a linking group, and R ²¹ , R ²² , and R ²³ are each independently a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, or an amide group. An amino group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, and the like, and these groups are substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, and the like. It may be. R ²⁴ represents a substitutable group or atom. m ² represents an integer of 0 to 4, and k ² represents an integer of 2 or more.

The compound represented by the general formula (3) will be described in more detail. As the linking group for Z ² , an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an arylene group, —N (R ⁵ ) —, —C (O) —O—, —C (R ⁶ ) ═N—, Examples include —C (O) —, a sulfonyl group, a heterocyclic structure, a benzene ring structure, or a group in which two or more are combined. Here, R ⁵ and R ⁶ represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

The heterocyclic structure constituting the linking group represented by Z ² includes pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring , Thiadiazole ring, thiatriazole ring, indole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring , Triazine ring, quinoline ring, quinoxaline ring and the like nitrogen-containing heterocycle, furan ring, thiophene ring, etc., and these heterocyclic structures further include alkyl groups, amino groups, aryl groups, alkenyl groups, carboxy groups, sulfo groups. Group, hydroxy It may have a substituent like.

Examples of the substitutable group or atom represented by R ²⁴ include a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkoxy group, and an aryloxy group. Furthermore, these groups or atoms may have a substituent such as an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, or a hydroxy group.

Among the compounds represented by the general formula (3), those having the structure shown below are preferable. That is, R ²¹ and R ²² in the general formula (3) are hydrogen atoms, R ²³ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.), and k ² is an integer of 2-10. Is preferred.

  Specific examples (C-1) to (C-11) of the compound represented by the general formula (3) are shown below, but are not limited to these specific examples.

About these addition polymerizable compounds, the details of usage, such as the structure, single use or combined use, and addition amount can be arbitrarily set according to the final performance design. For example, it is selected from the following viewpoints. From the viewpoint of photosensitive speed, a structure having a high unsaturated group content per molecule is preferable, and in many cases, a bifunctional or higher functionality is preferable. Further, in order to increase the strength of the image portion, that is, the cured film, those having three or more functionalities are preferable, and furthermore, different functional numbers and different polymerizable groups (for example, acrylic ester, methacrylic ester, styrenic compound, A method of adjusting both photosensitivity and strength by using a vinyl ether compound) is also effective. A compound having a large molecular weight or a compound having high hydrophobicity is excellent in photosensitive speed and film strength, but is not preferable in terms of development speed and precipitation in a developer. In addition, the selection and use method of the addition polymerization compound is also an important factor for the compatibility and dispersibility with other components constituting the photosensitive layer (for example, binder polymer, polymerization initiator, colorant, etc.). For example, the compatibility may be improved by using a low-purity compound or using two or more kinds in combination.
In the planographic printing plate precursor, a specific structure may be selected for the purpose of improving the adhesion to a support or a protective layer described later.

With respect to the content of the addition polymerizable compound in the photosensitive layer, the sensitivity, the occurrence of phase separation, the adhesiveness of the photosensitive layer, and the solid content in the photosensitive layer from the viewpoint of precipitation from the developer, Preferably it is 5-80 mass%, More preferably, it is used in 40-75 mass%.
The addition polymerizable compounds may be used alone or in combination of two or more. In addition, as for the method of using the addition polymerizable compound, an appropriate structure, blending, and addition amount can be arbitrarily selected from the viewpoints of polymerization inhibition with respect to oxygen, resolution, fogging property, refractive index change, surface tackiness, and the like. Furthermore, the lithographic printing plate precursor used in the present invention can also be subjected to a layer constitution / coating method such as undercoating or overcoating.

(Binder polymer)
The binder polymer is contained from the viewpoint of improving the film property, and various types can be used as long as it has a function of improving the film property.

-Specific binder polymer (1)-
Examples of the binder polymer suitable in the present invention include binder polymers having a repeating unit represented by the following general formula (i).
Hereinafter, the binder polymer having the repeating unit represented by the general formula (i) is appropriately referred to as a specific binder polymer (1) and will be described in detail.

(In General Formula (i), R ¹ represents a hydrogen atom or a methyl group, and R ² contains two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. And a linking group having a total number of atoms of 2 to 82. A represents an oxygen atom or —NR ³ —, and R ³ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. N represents an integer of 1 to 5.)

First, R ¹ in the general formula (i) represents a hydrogen atom or a methyl group, and a methyl group is particularly preferable.

The linking group represented by R ² in the general formula (i) includes two or more atoms selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. The number is 2 to 82, preferably 2 to 50, and more preferably 2 to 30. The total number of atoms shown here refers to the number of atoms including the substituent when the linking group has a substituent. More specifically, the number of atoms constituting the main skeleton of the linking group represented by R ² is preferably 1-30, more preferably 3-25, and 4-20. More preferred is 5-10. The “main skeleton of the linking group” in the present invention refers to an atom or an atomic group used only for linking A and the terminal COOH in the general formula (i), and particularly when there are a plurality of linking paths. Refers to an atom or atomic group that constitutes a path with the least number of atoms used. Therefore, when a linking group has a ring structure, the number of atoms to be included differs depending on the linking site (for example, o-, m-, p-, etc.).

More specific examples include alkylene, substituted alkylene, arylene, substituted arylene, and the like, and a structure in which a plurality of these divalent groups are linked by an amide bond or an ester bond may be used.
Examples of the linking group having a chain structure include ethylene and propylene. A structure in which these alkylenes are linked via an ester bond can also be exemplified as a preferable example.

Among these, the linking group represented by R ² in the general formula (i) is preferably an (n + 1) -valent hydrocarbon group having an aliphatic cyclic structure having 3 to 30 carbon atoms. More specifically, a compound having an aliphatic cyclic structure such as cyclopropane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, dicyclohexyl, tercyclohexyl, norbornane and the like, which may be substituted by one or more arbitrary substituents And (n + 1) valent hydrocarbon groups by removing (n + 1) hydrogen atoms on an arbitrary carbon atom constituting. R ² preferably has 3 to 30 carbon atoms including a substituent.

One or more arbitrary carbon atoms of the compound constituting the aliphatic cyclic structure may be replaced with a heteroatom selected from a nitrogen atom, an oxygen atom, or a sulfur atom. In terms of printing durability, R ² represents a condensed polycyclic aliphatic hydrocarbon, a bridged cyclic aliphatic hydrocarbon, a spiro aliphatic hydrocarbon, an aliphatic hydrocarbon ring assembly (a plurality of rings are connected by a bond or a linking group). A (n + 1) valent hydrocarbon group having an aliphatic cyclic structure which may have a substituent of 5 to 30 carbon atoms containing two or more rings. . Also in this case, the carbon number includes the carbon atom of the substituent.

As the linking group represented by R ² , those having 5 to 10 atoms constituting the main skeleton of the linking group are particularly preferred, and are structurally a chain structure, and an ester bond in the structure. And those having a cyclic structure as described above are preferred.

Examples of the substituent that can be introduced into the linking group represented by R ² include monovalent nonmetallic atomic groups other than hydrogen, such as halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups. Group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N- Diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy , Arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-aryl Ureido group, N ′, N′-diarylureido group, N′-alkyl-N′-arylureido group, N-alkylureido group, N-arylureido group, N′-alkyl-N-alkylureido group, N ′ -Alkyl-N-arylureido group, N ', N'-dialkyl-N-alkylureido group, N', N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N ' -Aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-al Kill-N′-aryl-N-alkylureido group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, Alkylsulfinyl group An arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group, alkoxy sulfonyl group, aryloxy sulfonyl group, sulfinamoyl group, N- alkylsulfinamoyl group, N, N- Dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N -Dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N- alkylsulfonylsulfamoyl group (-SO ₂ NHSO ₂ alkyl)) and its conjugated base group, N- aryl sulfonylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugate Base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl Group (—Si (OH) ₃ ) and its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (— PO ₃ (aryl) _2), alkyl aryl phosphono group _{(-PO 3 (alkyl) (aryl} )) , Monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) And its conjugate base group, dialkylphosphonooxy group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) ( aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, group, ₍₂ -B (alkyl)) dialkyl boryl group, Jiariruboriru group (-B (aryl) _2), alkyl aryl boryl -B (alkyl) (aryl)) , dihydroxy boryl group (-B (OH) ₂₎ and its conjugated base group, an alkyl hydroxy boryl group (-B (alkyl) (OH) ) and its conjugated base group, an aryl hydroxy boryl And the group (—B (aryl) (OH)) and its conjugate base group, aryl group, alkenyl group and alkynyl group.

  In the lithographic printing plate precursor used in the present invention, depending on the design of the photosensitive layer, a substituent having a hydrogen atom capable of hydrogen bonding, particularly a substitution having an acidity having a smaller acid dissociation constant (pKa) than carboxylic acid. The group is not preferable because it tends to lower the printing durability. On the other hand, hydrophobic substituents such as halogen atoms, hydrocarbon groups (alkyl groups, aryl groups, alkenyl groups, alkynyl groups), alkoxy groups, aryloxy groups and the like are more preferable because they tend to improve printing durability. When the cyclic structure is a monocyclic aliphatic hydrocarbon having 6 or less members such as cyclopentane or cyclohexane, it preferably has such a hydrophobic substituent. If possible, these substituents may be bonded to each other or with a substituted hydrocarbon group to form a ring, and the substituent may be further substituted.

R ³ in the case where A in formula (i) is NR ³ — represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ³ include an alkyl group, an aryl group, an alkenyl group, and an alkynyl group.
Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, isopropyl group, isobutyl group, sec-butyl group, 1 carbon number such as tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-norbornyl group Up to 10 linear, branched or cyclic alkyl groups.
Specific examples of the aryl group include carbon having one heteroatom selected from the group consisting of an aryl group having 1 to 10 carbon atoms such as a phenyl group, a naphthyl group, and an indenyl group, a nitrogen atom, an oxygen atom, and a sulfur atom. Examples include heteroaryl groups of 1 to 10, such as furyl, thienyl, pyrrolyl, pyridyl, and quinolyl groups.
Specific examples of the alkenyl group include those having 1 to 10 carbon atoms such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group, 1-cyclohexenyl group and the like. A linear, branched, or cyclic alkenyl group is mentioned.
Specific examples of the alkynyl group include alkynyl groups having 1 to 10 carbon atoms such as ethynyl group, 1-propynyl group, 1-butynyl group, and 1-octynyl group. The substituent that R ³ may have is the same as those exemplified as the substituent that R ² can introduce. However, the carbon number of R < ³ > is 1-10 including the carbon number of a substituent.

  A in the general formula (i) is preferably an oxygen atom or —NH— because synthesis is easy.

  N in the general formula (i) represents an integer of 1 to 5, and is preferably 1 in terms of printing durability.

  Although the preferable specific example of the repeating unit represented by general formula (i) below is shown, this invention is not limited to these.

  One type of repeating unit represented by the general formula (i) may be contained in the binder polymer, or two or more types may be contained. The specific binder polymer (1) in the present invention may be a polymer consisting only of the repeating unit represented by the general formula (i), but is usually combined with other copolymerization components and used as a copolymer. The total content of the repeating unit represented by the general formula (i) in the copolymer is appropriately determined depending on its structure, the design of the photosensitive layer composition, etc., but preferably 1 to 99 with respect to the total molar amount of the polymer component. It is contained in the range of mol%, more preferably 5 to 40 mol%, still more preferably 5 to 20 mol%.

  As a copolymerization component in the case of using as a copolymer, a conventionally well-known thing can be used without a restriction | limiting, if it is a monomer which can be radically polymerized. Specific examples include monomers described in “Polymer Data Handbook—Basic Edition” (Edition of Polymer Society, Bafukan, 1986). One type of such copolymerization component may be used, or two or more types may be used in combination.

The molecular weight of the specific binder polymer (1) used in the present invention is appropriately determined from the viewpoint of image formability and printing durability. The molecular weight is preferably in the range of 2,000 to 1,000,000, more preferably 5,000 to 500,000, and still more preferably 10,000 to 200,000.
The acid value (meq / g) of the specific binder polymer (1) is preferably in the range of 2.00 to 3.60.

The specific binder polymer (1) in the present invention may be used alone or in combination with one or more other binder polymers.
The binder polymer used in combination is used in the range of 1 to 60% by mass, preferably 1 to 40% by mass, and more preferably 1 to 20% by mass with respect to the total mass of the binder polymer component.
As the binder polymer that can be used in combination, conventionally known ones can be used without limitation, and specifically, an acrylic main chain binder, a urethane binder, etc. often used in the industry, and a binder polymer having a radical polymerizable group described later. Is preferably used.

-Other binder polymers that can be used together-
The other binder polymer that can be used in combination with the specific binder polymer (1) is preferably a binder polymer having a radical polymerizable group.
The radical polymerizable group is not particularly limited as long as it can be polymerized by radicals, but α-substituted methylacrylic group [—OC (═O) —C (—CH ₂ Z) ═CH ₂ , Z = A hydrocarbon group starting from a hetero atom], an acryl group, a methacryl group, an allyl group, and a styryl group. Among these, an acryl group and a methacryl group are preferable.
The content of the radical polymerizable group in the binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 1 g per binder polymer from the viewpoint of sensitivity and storage stability. It is 10.0 mmol, More preferably, it is 1.0-7.0 mmol, Most preferably, it is 2.0-5.5 mmol.

  Further, the other binder polymer that can be used in combination is preferably one having an alkali-soluble group. The content of alkali-soluble groups in the binder polymer (acid value by neutralization titration) is preferably from 0.1 to 3.0 mmol, more preferably from 1 to 3.0 g of binder polymer, from the viewpoints of precipitation of developing residue and printing durability. Is 0.2 to 2.0 mmol, most preferably 0.45 to 1.0 mmol.

  The weight average molecular weight of such a binder polymer is preferably from 2,000 to 1,000,000, more preferably from 10,000 to 300, from the viewpoints of film properties (press life) and solubility in a coating solvent. In the range of 20,000 to 200,000.

Further, the glass transition point (Tg) of such a binder polymer is preferably 70 to 300 ° C., more preferably 80 to 250 ° C., and most preferably 90 to 90 ° C. from the viewpoints of storage stability, printing durability, and sensitivity. It is in the range of 200 ° C.
As a means for increasing the glass transition point of the binder polymer, the molecule preferably contains an amide group or an imide group, and particularly preferably contains a methacrylamide or a methacrylamide derivative.

In the present invention, further, Japanese Patent Publication No. 7-12004, Japanese Patent Publication No. 7-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Publication No. 63-287944, Japanese Patent Publication No. 63-287947, Urethane-based binder polymers containing acid groups described in JP-A-1-2717741, Japanese Patent Application No. 11-352691 and the like can also be used. Since the binder polymer is very excellent in strength, it is advantageous in terms of printing durability and suitability for low exposure.
A binder having an amide group described in JP-A No. 11-171907 is suitable because it has excellent developability and film strength.

  In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful.

In a preferred embodiment, a binder polymer that does not require water and is soluble in alkali is used. By doing so, an organic solvent that is not environmentally preferable is not used as the developer, or the amount used can be limited to a very small amount. In such a method of use, the acid value of the binder polymer (the acid content per gram of polymer expressed as a chemical equivalent number) and the molecular weight are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, and the preferred molecular weight is in the range of 3000 to 500,000 in terms of mass average molecular weight, more preferably the acid value is 0.6 to 2.0 and the molecular weight is It is in the range of 10,000 to 300,000.
In addition, these binder polymers can be used together with the specific binder polymer (2) and the specific binder polymer (3) described later as necessary.

-Specific binder polymer (2)-
In addition, as the binder polymer in the present invention, a binder polymer having a phenyl group substituted with a vinyl group in the side chain (hereinafter, appropriately referred to as a specific binder polymer (2)) can also be suitably used.
The binder polymer having a phenyl group substituted with a vinyl group in the side chain is one in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or via a linking group. The linking group is not particularly limited, and includes any group, atom, or a complex group thereof. In addition to the vinyl group, the phenyl group may be substituted with a substitutable group or atom. Specific examples of the substitutable group or atom include a halogen atom, a carboxy group, and a sulfo group. Group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkoxy group, aryloxy group and the like. Furthermore, the vinyl group may be substituted with a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or the like.

  The specific binder polymer (2) is preferably a binder polymer having a group represented by the following general formula (2) in the side chain.

In general formula (2), Z ¹ represents a linking group, and R ¹ , R ² , and R ³ each independently represent a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, or an amide group. Represents an amino group, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, and the like, and these groups are substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, and the like. It may be. R ⁴ represents a substitutable group or atom. n represents 0 or 1, m ¹ represents an integer of 0 to 4, and k ¹ represents an integer of ¹ to 4.

The general formula (2) will be described in more detail.
R ⁴ is preferably a hydrogen atom.
Examples of the linking group represented by Z ¹ include an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an arylene group, —N (R ^a ) —, —C (O) —O—, —C (R ^b ) = N—, —C (O) —, a sulfonyl group, a heterocyclic group, and a group represented by the following structural formula, or a group in which two or more are combined. Here, R ^a and R ^b each represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

  Examples of the heterocyclic group include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thiatriazole ring, indole ring. , Indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, quinoxaline ring, etc. A nitrogen-containing heterocyclic ring, a furan ring, a thiophene ring and the like, and a substituent may be bonded to these heterocyclic rings.

Specific examples of the binder polymer having the group represented by the general formula (2) in the side chain include those shown below, but are not limited thereto.
In addition, in a structural formula, a number represents the mass% of each repeating unit in 100 mass% of all compositions of a copolymer.

  The weight average molecular weight of the specific binder polymer (2) is preferably 5000 to 1,000,000, more preferably 10,000 to 500,000, and 20,000 to 300,000. Is more preferable.

-Specific binder polymer (3)-
Moreover, the organic polymer which has an allyl group can also be used suitably as a binder polymer in this invention.
In particular, a binder polymer containing 0.7 meq / g to 8.0 meq / g of allyl group (that is, 7 × 10 ⁻⁴ mol to 8.0 × 10 ⁻³ mol of allyl group per gram) is preferable. Hereinafter, this binder polymer will be referred to as a specific binder polymer (3).

The specific binder polymer (3) is preferably a polymer or copolymer of allyl acrylate and / or allyl methacrylate.
More specifically, homopolymers such as polyallyl methacrylate, the above allyl acrylate and / or allyl methacrylate, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate , Butyl acrylate, butyl methacrylate, their alkyl esters, vinyl acetate, styrene, maleic anhydride, copolymers with other monomers such as acrylonitrile.

Another preferred example of the specific binder polymer (3) includes a polyurethane having an allyl group which may be either a pendant allyl group or a terminal allyl group (hereinafter referred to as an allyl group-containing polyurethane).
Polyurethanes having allyl groups can be prepared by reacting diisocyanates with diols having excess allyl groups to form polyurethanes.
Also, by reacting diisocyanate with a diol having a carboxyl group such as dimethylolpropionic acid, a polyurethane having a carboxyl group is prepared, and this carboxyl group is esterified with, for example, allyl alcohol to form an allyl ester group. A polyurethane having an allyl group can be obtained by converting to.

Examples of the diol having an allyl group include 3-allyloxy-1,2-propanediol and trimethylolpropane allyl ether. Examples of the diol having an allyl ester group include allyl 4,4-bis (hydroxyethyloxyphenyl) -pentanoate and 2,2-bis (hydroxymethyl) propanoate. Preferred diols are 3-allyloxy-1,2-propanediol: a _{(HO) CH 2 -CH (OH} ) -CH 2 -O-CH 2 -CH = CH 2.

These diols having an allyl group can be used alone or in combination, or further in combination with a diol containing no allyl group. However, these diols are used under conditions such that allyl groups are present in the range of 0.7 meq / g to 8.0 meq / g in the obtained polymer.
Examples of diols that do not contain allyl groups used in ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, neopentyl glycol, 1,4-butanediol, and 1,6-hexanediol. Can be mentioned.

The polyurethane having an allyl group may contain an acid group, that is, a group having _a pKa of 7 or less (for example, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, or a carboxylic acid group). Such polyurethanes are obtained by reacting an excess of a mixture of a diol having an allyl group and a diol containing one or more acid groups with a diisocyanate as described above. Useful diols containing one or more acid groups include, for example, dialkanol alkyl sulfonic acids, dialkanol alkyl phosphoric acids, and dialkanol alkyl phosphonic acids.

The polyurethane having an allyl group and an acid group is preferably a polyurethane having a carboxyl group and an allyl group. A polyurethane having a carboxyl group and an allyl group is obtained by reacting a diisocyanate with an excess of a mixture of an allyl group-containing diol and a carboxyl group-containing diol to form a polyurethane.
The mixing ratio in the mixture of diols is determined under conditions such that allyl groups are present in the range of 0.7 meq / g to 8.0 meq / g in the resulting polymer.

  Examples of useful diols having a carboxyl group include 2,2-bis (hydroxymethyl) propionic acid, (2,2-dimethylolpropanoic acid), 2,2-bis (2-hydroxyethyl) propanoic acid, 2,2-bis (3-hydroxypropyl) propanoic acid, bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 2,2-bis (hydroxymethyl) butyric acid, 2,2-bis (hydroxymethyl) Dialkanol alkanoic acid such as pentanoic acid and tartaric acid, dihydroxybenzoic acid such as 3,5-dihydroxybenzoic acid, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride or 2,3,6,7-naphthalenetetracarboxylic dianhydride Acid dianhydrides such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, 1,2- or 1,3-propanediol, polypropylene glycol, 1,2- or 1,4-butanediol, neopentyl Examples thereof include dihydroxydicarboxylic acid obtained by reacting a diol with an acid dianhydride such as a reaction product of a diol such as glycol or 1,6-hexanediol.

In addition, aromatic and / or aliphatic diisocyanates can be used as the isocyanate used when synthesizing the polyurethane.
Examples of the aromatic diisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, tetramethylxylene diisocyanate, 4 , 4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 3,3′-dimethylbiphenyl-4,4′-diisocyanate.
Examples of the aliphatic diisocyanate include hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4-methylene-bis (cyclohexyl isocyanate), methylcyclohexane-2,4- and 2 , 6-diisocyanate, and 1,4-bis (isocyanatomethyl) cyclohexane.
In the present invention, aromatic diisocyanate is preferably used.

  The specific binder polymer (3) as described above is 5,000 to 1,000,000, preferably 100,000 or less, more preferably 75,000 or less, as measured by gel permeation chromatography. More preferably, it has a weight average molecular weight of 50,000 or less.

The specific binder polymer (3) molecule may be a linear molecule or a branched molecule, and preferably has a polydispersity of 1 to 5.
The specific binder polymer (3) preferably has an acid value of 0 to 70 mgKOH / g, more preferably has an acid value of 0 to 50 mgKOH / g, and has an acid value of 0 to 30 mgKOH / g. Is more preferable.

In the present invention, the total amount of the binder polymer in the photosensitive layer can be appropriately determined, but is usually 10 to 90% by mass, preferably 20 to 80% by mass, based on the total mass of nonvolatile components in the photosensitive layer. %, More preferably in the range of 30 to 70% by mass.
Moreover, it is preferable to make the polymeric compound and binder polymer mentioned later into the range of 1 / 9-7 / 3 by mass ratio.

(Other ingredients)
In addition to the above basic components, other components suitable for the application, production method and the like can be appropriately added to the photosensitive layer in the invention. Hereinafter, preferred additives will be exemplified.

-Colorant-
A dye or pigment may be added to the photosensitive layer for the purpose of coloring. As a result, it is possible to improve the so-called plate inspection properties such as the visibility of the image after plate making as a printing plate and the suitability of an image density measuring machine. Specific examples of the colorant include pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. Among them, a cationic dye is preferable.
Further, as the colorant, a dye having an absorption maximum having a polymerization inhibiting effect in the range of 500 nm to 700 nm may be used in addition to the plate inspection properties as described above. As this dye, those described in paragraph numbers [0013] to [0017] of JP-A-2005-107389 are used.
The addition amount of the dye and the pigment as the colorant is preferably about 0.5% by mass to about 5% by mass with respect to the nonvolatile component in the photosensitive layer.

-Polymerization inhibitor-
In the photosensitive layer and the coating solution for forming a photosensitive layer used for forming the photosensitive layer in the present invention, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound. . Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4′-thiobis (3-methyl-6-t- Butylphenol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the nonvolatile component in the photosensitive layer (or photosensitive layer forming coating solution).
If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide or the like may be added to prevent polymerization inhibition by oxygen and may be unevenly distributed on the surface of the layer in the course of drying after coating. The addition amount of the higher fatty acid derivative is preferably about 0.5% by mass to about 10% by mass with respect to the nonvolatile component in the photosensitive layer (or the photosensitive layer forming coating solution).

-A compound having a weight average molecular weight of 3,000 or less and having at least one carboxylic acid group-
The photosensitive layer in the present invention may contain a compound having a weight average molecular weight of 3,000 or less and having at least one carboxylic acid group (hereinafter, appropriately referred to as a specific carboxylic acid compound). This specific carboxylic acid compound is, for example, an aliphatic carboxylic acid that may have a substituent, an aromatic carboxylic acid that may have a substituent, and a heterocyclic ring that may have a substituent. It can be selected from compounds such as directly linked carboxylic acids. Among these, phthalic acid derivatives, trimellitic acid derivatives, pyromellitic acid derivatives, succinic acid derivatives, benzoic acid derivatives, glycine derivatives, and the like are preferable.

  In the present invention, the specific carboxylic acid compound has a weight average molecular weight of 3000 or less, more preferably in the range of 60 to 2000, and still more preferably in the range of 100 to 1500. When the weight average molecular weight exceeds 3000, the specific carboxylic acid compound may be adsorbed on the support, which is not preferable.

  Specific examples (compounds No. 1 to No. 20) of the specific carboxylic acid compound suitably used in the present invention are listed below, but the present invention is not limited to these.

[Support]
Examples of the support in the present invention include paper, a polyester film or an aluminum plate. Among them, a surface having good dimensional stability, relatively inexpensive, and having excellent hydrophilicity and strength by surface treatment as necessary. An aluminum plate that can be provided is more preferred. A composite sheet in which an aluminum sheet is bonded on a polyethylene terephthalate film as described in Japanese Patent Publication No. 48-18327 is also preferable.

  The aluminum plate as the most preferable support in the present invention is a metal plate mainly composed of dimensionally stable aluminum, and contains pure aluminum plate, aluminum as a main component, and a trace amount of foreign elements. An alloy plate or aluminum (alloy) is selected from a laminated or vapor-deposited plastic film or paper. In the following description, the above-mentioned support made of aluminum or an aluminum alloy is generically used as an aluminum support. Examples of the foreign element contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of the foreign element in the alloy is 10% by mass or less. In the present invention, a pure aluminum plate is suitable, but since completely pure aluminum is difficult to manufacture in the refining technique, it may contain a slightly different element. Thus, the composition of the aluminum plate applied to the present invention is not specified, and it is a conventionally known material such as JIS A 1050, JIS A 1100, JIS A 3103, JIS A 3005, etc. Can be used as appropriate.

Moreover, the thickness of the aluminum support body used for this invention is about 0.1 mm-about 0.6 mm. This thickness can be changed as appropriate according to the size of the printing press, the size of the printing plate, and the desire of the user.
Such a support (aluminum support) is subjected to a surface treatment described later to be hydrophilized.

(Roughening treatment)
Examples of the roughening treatment method include mechanical roughening, chemical etching, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, the electrochemical surface roughening method in which the surface is electrochemically roughened in hydrochloric acid or nitric acid electrolyte solution, the aluminum surface is scratched with a metal wire, the wire brush grain method, the surface of the aluminum is polished with a polishing ball and an abrasive. A mechanical graining method such as a pole grain method, a brush grain method in which the surface is roughened with a nylon brush and an abrasive, can be used, and the above roughening methods can be used alone or in combination. Among them, a method usefully used for roughening is an electrochemical method in which roughening is performed chemically in hydrochloric acid or nitric acid electrolyte, and a suitable amount of electricity at the time of anode is 50 C / dm ^{2 to} 400 C / dm ² . It is a range. More specifically, in the electrolytic solution containing from 0.1 to 50% hydrochloric acid or nitric acid, the temperature 20 to 80 ° C., for 1 second to 30 minutes, alternating at a current density of 100C / dm ² ~400C / dm ² It is preferable to perform direct current electrolysis.

  The roughened aluminum support may be chemically etched with acid or alkali. Etching agents suitably used are caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like, and preferred ranges of concentration and temperature are 1 to 50% and 20%, respectively. ~ 100 ° C. Pickling is performed to remove dirt (smut) remaining on the surface after etching. As the acid used, nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, borohydrofluoric acid and the like are used. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123. After the treatment as described above, the method and conditions are not particularly limited as long as the surface roughness Ra of the treated surface is about 0.2 to 0.5 μm.

(Anodizing treatment)
The aluminum support that has been treated as described above to form an oxide layer is then anodized.
In the anodizing treatment, sulfuric acid, phosphoric acid, oxalic acid, or an aqueous solution of boric acid / sodium borate is used alone or in combination as a main component of the electrolytic bath. In this case, the electrolyte solution may of course contain at least components normally contained in at least an Al alloy plate, an electrode, tap water, groundwater and the like. Further, the second and third components may be added. Here, the second and third components are, for example, metal ions such as Na, K, Mg, Li, Ca, Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, and ammonium ions. Examples include cations, nitrate ions, carbonate ions, chloride ions, phosphate ions, fluorine ions, sulfite ions, titanate ions, silicate ions, borate ions and the like, and the concentration is 0 to 10,000 ppm. May be included. There are no particular limitations on the conditions of the anodizing treatment, but the treatment is preferably carried out by direct current or alternating current electrolysis at a current density of 0.1 to 40 A / m ² at 30 to 500 g / liter, a treatment liquid temperature of 10 to 70 ° C. . The thickness of the formed anodic oxide film is in the range of 0.5 to 1.5 μm. Preferably it is the range of 0.5-1.0 micrometer. The support prepared by the above treatment is treated so that the pore diameter of the micropores existing in the anodized film is in the range of 5 to 10 nm and the pore density is in the range of 8 × 10 ¹⁵ to 2 × 10 ¹⁶ pieces / m ^2. It is preferred that the conditions are selected.

A widely known method can be applied as the hydrophilic treatment on the surface of the support. As a particularly preferable treatment, a hydrophilic treatment with silicate or polyvinylphosphonic acid is performed. A film | membrane is formed by 2-40 mg / m < ² > as Si or P element amount, More preferably, it is 4-30 mg / m < ² >. The coating amount can be measured by fluorescent X-ray analysis.

  The hydrophilization treatment is carried out by applying an anodized film to an aqueous solution containing 1 to 30% by mass, preferably 2 to 15% by mass of alkali metal silicate or polyvinylphosphonic acid, and having a pH of 10 to 13 at 25 ° C. This is carried out by immersing the aluminum support on which is formed, for example, at 15 to 80 ° C. for 0.5 to 120 seconds.

  As the alkali metal silicate used for the hydrophilization treatment, sodium silicate, potassium silicate, lithium silicate, or the like is used. Examples of the hydroxide used for increasing the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, you may mix | blend alkaline-earth metal salt or Group IVB metal salt with said process liquid. Alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble substances such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. Salt. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium fluoride titanium, potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can be mentioned.

  Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferable range of these metal salts is 0.01 to 10% by mass, and a more preferable range is 0.05 to 5.0% by mass. Silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective. Surface obtained by combining a support with electrolytic grains as disclosed in JP-B-46-27481, JP-A-52-58602, JP-A-52-30503, and the above anodizing treatment and hydrophilization treatment Processing is also useful.

[Intermediate layer (undercoat layer)]
The lithographic printing plate precursor used in the present invention may be provided with an intermediate layer (undercoat layer) for the purpose of improving the adhesion between the photosensitive layer and the support and the stain resistance. Specific examples of such an intermediate layer include JP-B-50-7481, JP-A-54-72104, JP-A-59-101651, JP-A-60-149491, JP-A-60-232998, JP-A-3-56177, JP-A-4-282737, JP-A-5-16558, JP-A-5-246171, JP-A-7-159983, JP-A-7-314937, JP-A-8-202025, Special Kaihei 8-320551, JP 9-34104, JP 9-236911, JP 9-269593, JP 10-69092, JP 10-115931, JP 10-161317, JP 10-260536, JP-A-10-282682, JP-A-11-84684, JP-A-10-69092, JP-A-10-115931, Kaihei 11-38635, JP-A-11-38629, JP-A-10-282645, JP-A-10-301262, JP-A-11-24277, JP-A-11-109641, JP-A-10-319600, JP-A-10-319600 11-84684, JP-A-11-327152, JP-A-2000-10292, JP-A-2000-235254, JP-A-2000-352854, JP-A-2001-209170, Japanese Patent Application No. 11-284091, etc. Can be mentioned.

<Plate making method>
Hereinafter, the plate making method of the lithographic printing plate precursor according to the invention will be described.
In the present invention, the lithographic printing plate precursor forms a laminate (laminate of the lithographic printing plate precursor) in which a plurality of layers are laminated by directly contacting the outermost surface on the recording layer side and the outermost surface on the backcoat layer side. Thereafter, the laminate can be set in a plate setter, the lithographic printing plate precursor is automatically conveyed one by one, exposed, and then subjected to development to make a plate.
Even if the lithographic printing plate precursor used in the present invention is laminated without interposing the interleaf between the plates, the adhesion between the lithographic printing plate precursor and the generation of scratches on the protective layer are suppressed, It can be applied to the plate making method as described above. In addition, since the laminated body (laminate of the lithographic printing plate precursor) obtained by laminating the lithographic printing plate precursor without interposing the interleaving paper can be used for the plate making method, it is not necessary to remove the interleaving paper, and in the plate making process Productivity is improved.

  In the case where the lithographic printing plate precursor has a protective layer provided on a polymerizable negative photosensitive layer having an infrared absorber as a sensitizing dye, a plurality of protective layers and a back coat layer are directly contacted and laminated. The laminated body is set in a plate setter, the lithographic printing plate precursor is automatically conveyed one by one, exposed at a wavelength of 750 nm to 1400 nm, and then subjected to a heating speed substantially without undergoing a heat treatment. Plate making can be carried out by carrying out development processing under conditions of 1.25 m / min or more.

〔exposure〕
As a light source used for the exposure processing, a known light source can be used without limitation. The wavelength of the light source is preferably in the range of 300 nm to 1200 nm. Specifically, various lasers can be used as the light source, and among them, a semiconductor laser that emits infrared light with a wavelength of 760 nm to 1200 nm can be used.

A laser is preferable as the light source. For example, the following laser light sources having a wavelength of 350 to 450 nm can be used.
As a gas laser, Ar ion laser (364 nm, 351 nm, 10 mW to 1 W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), He—Cd laser (441 nm, 325 nm, 1 mW to 100 mW), and solid laser Nd: A combination of YAG (YVO ₄ ) and SHG crystal × 2 times (355 mm, 5 mW to 1 W), a combination of Cr: LiSAF and SHG crystal (430 nm, 10 mW) may be mentioned. As the semiconductor laser system, KNbO ₃ , ring resonator (430 nm, 30 mW), waveguide type wavelength conversion element and AlGaAs, combination of InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), waveguide type wavelength conversion element and AlGaInP, Combination of AlGaAs semiconductors (300 nm to 350 nm, 5 mW to 100 mW), AlGaInN (350 nm to 450 nm, 5 mW to 30 mW), and other pulse lasers such as N ₂ laser (337 nm, pulse 0.1 to 10 mJ), XeF (351 nm, pulse 10 ~ 250 mJ).
In particular, an AlGaInN semiconductor laser (commercially available InGaN-based semiconductor laser 400 to 410 nm, 5 to 30 mW) is preferable in terms of wavelength characteristics and cost.

Other available light sources of 450 nm to 700 nm include Ar ⁺ laser-(488 nm), YAG-SHG laser (532 nm), He-Ne laser (633 nm), He-Cd laser, and red semiconductor laser (650-690 nm). In addition, as an available light source of 700 nm to 1200 nm, a semiconductor laser (800 to 850 nm) and an Nd-YAG laser (1064 nm) can be suitably used.

  In addition, ultra high pressure, high pressure, medium pressure, low pressure mercury lamp, chemical lamp, carbon arc lamp, xenon lamp, metal halide lamp, ultraviolet laser lamp (ArF excimer laser, KrF excimer laser, etc.), various visible laser lamps, fluorescent light An electron beam, an X-ray, an ion beam, a far-infrared ray, or the like can be used as the radiation such as a lamp, a tungsten lamp, or sunlight.

  Among the above, as a light source of light used for image exposure, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid laser or a semiconductor laser is particularly preferable.

In particular, when a wavelength of 750 nm to 1400 nm is used as an exposure light source, it can be used without particular limitation as long as it emits light of the wavelength, but preferably an image is emitted by a solid laser or semiconductor laser emitting infrared rays of a wavelength of 750 nm to 1400 nm. It is preferable to be exposed.
The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec. The amount of energy per unit irradiated on the lithographic printing plate precursor is preferably 10 to 300 mJ / cm ² .

  In the exposure processing in the present invention, exposure can be performed by overlapping light beams of light sources. Overlap means that the sub-scanning pitch width is smaller than the beam diameter. The overlap can be expressed quantitatively by FWHM / sub-scanning pitch width (overlap coefficient), for example, when the beam diameter is expressed by the half width (FWHM) of the beam intensity. In the present invention, the overlap coefficient is preferably 0.1 or more.

  The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylindrical outer surface scanning method, a cylindrical inner surface scanning method, a planar scanning method, or the like can be used. The channel of the light source may be a single channel or a multi-channel, but the multi-channel is preferably used in the case of a cylindrical outer surface type.

In the present invention, the lithographic printing plate precursor subjected to the exposure treatment as described above may be subjected to a heat treatment and a water washing treatment.
Further, depending on the type of the lithographic printing plate precursor, for example, when it has a polymerizable negative photosensitive layer, it may be subjected to development processing without performing special heat treatment and water washing treatment. By not performing this heat treatment, image non-uniformity due to the heat treatment can be suppressed. Further, by performing neither heat treatment nor water washing treatment, stable high-speed processing is possible in development processing.

〔developing〕
In the development processing in the present invention, a non-image portion of the photosensitive layer is removed using a developer.
In the present invention, as described above, in the case of a lithographic printing plate precursor having a protective layer on a polymerizable negative photosensitive layer having an infrared absorber as a sensitizing dye, the processing speed in the development process, That is, the transport speed (line speed) of the lithographic printing plate precursor in the development process is preferably 1.25 m / min or more, more preferably 1.35 m / min or more. Moreover, there is no restriction | limiting in particular in the upper limit of a conveyance speed, However, From a viewpoint of stability of conveyance, it is preferable that it is 3 m / min or less.
Hereinafter, the developer used in the present invention will be described.

(Developer)
The developer used in the present invention is preferably an alkaline aqueous solution having a pH of 14 or less, and preferably contains an aromatic anionic surfactant.

(Aromatic anionic surfactant)
The aromatic anionic surfactant used in the developer in the present invention has a development accelerating effect and a dispersion stabilizing effect in the developer of the polymerizable negative photosensitive layer component and the protective layer component. preferable. Among these, the aromatic anionic surfactant used in the present invention is preferably a compound represented by the following general formula (A) or general formula (B).

In the above general formula (A) or general formula (B), R ¹ and R ³ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, specifically an ethylene group. , Propylene group, butylene group, pentylene group, and the like, among which ethylene group and propylene group are particularly preferable.
m and n each independently represent an integer selected from 1 to 100. Among them, 1 to 30 are preferable, and 2 to 20 are more preferable. When m is 2 or more, a plurality of R ¹ may be the same or different. Similarly, when n is 2 or more, a plurality of R ³ may be the same or different.
t and u each independently represents 0 or 1.

R ² and R ⁴ each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, hexyl group, dodecyl group Among them, a methyl group, an ethyl group, an iso-propyl group, an n-propyl group, an n-butyl group, an iso-butyl group, and a tert-butyl group are particularly preferable.
p and q each represent an integer selected from 0 to 2; Y ¹ and Y ² each represent a single bond or an alkylene group having 1 to 10 carbon atoms. Specifically, a single bond, a methylene group or an ethylene group is preferred, and a single bond is particularly preferred.
(Z ¹ ) ^{r +} and (Z ² ) ^{s +} each independently represents an alkali metal ion, an alkaline earth metal ion, or an ammonium ion that is unsubstituted or substituted with an alkyl group. Sodium ion, potassium ion, magnesium ion, calcium ion, ammonium ion, secondary to quaternary ammonium ion substituted with an alkyl group, aryl group, or aralkyl group in the range of 1 to 20 carbon atoms, etc. In particular, sodium ion is preferable. r and s each represent 1 or 2.
Specific examples are shown below, but the present invention is not limited thereto.

  These aromatic anionic surfactants may be used alone or in appropriate combination of two or more. The amount of the aromatic anionic surfactant added is preferably such that the concentration of the aromatic anionic surfactant in the developer is in the range of 1.0 to 10% by mass, more preferably in the range of 2 to 10% by mass. It is effective to do. Here, if the content is 1.0% by mass or less, the developability and the solubility of the photosensitive layer components are lowered, and if the content is 10% by mass or more, the printing durability of the printing plate is reduced. .

In addition to the aromatic anionic surfactant, other surfactants may be used in combination with the developer. Examples of other surfactants include polyoxyethylene naphthyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene stearyl ether, Polyoxyethylene alkyl esters such as oxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan triesterate and other sorbitan alkyl esters, glycerol mono Nonionic surfactants such as monoglyceride alkyl esters such as stearate and glycerol monooleate.
The content of these other surfactants in the developer is preferably from 0.1 to 10% by mass in terms of active ingredients.

(Chelating agent for divalent metals)
For example, the developer preferably contains a chelating agent for a divalent metal in order to suppress the influence of calcium ions contained in hard water. Examples of the chelating agent for the divalent metal include Na ₂ P ₂ O ₇ , Na ₅ P ₃ O ₃ , Na ₃ P ₃ O ₉ , Na ₂ O ₄ P (NaO ₃ P) PO ₃ Na ₂ , Calgon (polymetaline). Polyphosphates such as ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; diethylenetriaminepentaacetic acid, its potassium salt, sodium salt; triethylenetetraminehexaacetic acid, its potassium salt, its sodium salt Hydroxyethylethylenediaminetriacetic acid, its potassium salt, its sodium salt; nitrilotriacetic acid, its potassium salt, its sodium salt; 1,2-diaminocyclohexanetetraacetic acid, its potassium salt, its sodium salt; 1,3-diamino-2 -Propanol tetraacetic acid, its potassium salt, 2-phosphonobutanetricarboxylic acid-1,2,4, potassium salt thereof, sodium salt thereof; 2-phosphonobutanone tricarboxylic acid-2,3,4, 1-phosphonoethanetricarboxylic acid-1,2,2, potassium salt, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri And organic phosphonic acids such as (methylenephosphonic acid), its potassium salt, its sodium salt, etc. Among them, ethylenediaminetetraacetic acid, its potassium salt, its sodium salt, its amine salt; ethylenediaminetetra (methylenephosphonic acid) ), Its ammonium salt, its potassium salt; hexamethyl Emissions diamine tetra (methylene phosphonic acid), an ammonium salt, its potassium salt is preferred.
The optimum amount of such a chelating agent varies depending on the hardness of the hard water used and the amount used, but is generally 0.01 to 5% by mass, more preferably 0% in the developing solution at the time of use. It is made to contain in the range of 0.01-0.5 mass%.

  Further, an alkali metal salt of an organic acid or an alkali metal salt of an inorganic acid may be added to the developer according to the present invention as a development regulator. For example, sodium carbonate, potassium, ammonium, sodium citrate, potassium, ammonium and the like may be used alone or in combination of two or more.

(Alkaline agent)
Examples of the alkali agent used in the developer include inorganic alkalis such as trisodium phosphate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, potassium, ammonium, and lithium. Agents, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol Examples include organic alkali agents such as noramine, ethyleneimine, ethylenediamine, pyridine, and tetramethylammonium hydroxide. In the present invention, these may be used alone or in combination of two or more.

  Moreover, alkali silicate can be mentioned as alkali agents other than the above. Alkali silicates may be used in combination with a base. The alkali silicate to be used exhibits alkalinity when dissolved in water, and examples thereof include sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. These alkali silicates may be used alone or in combination of two or more.

The developer used in the present invention is composed of silicon oxide SiO ₂ which is a silicate component as a hydrophilizing component of a support and alkali oxide M ₂ O as an alkali component (M represents an alkali metal or ammonium group). By adjusting the mixing ratio and concentration, it can be easily adjusted to the optimum range. The mixing ratio (SiO ₂ / M ₂ O molar ratio) of silicon oxide SiO ₂ and alkali oxide M ₂ O is the amount of unclean dirt caused by excessive dissolution (etching) of the anodic oxide film of the support. From the viewpoint of suppressing the generation of insoluble gas resulting from complex formation between dissolved aluminum and silicate, the range is preferably 0.75 to 4.0, more preferably 0.75 to 3.5. Used in.

In addition, the alkali silicate concentration in the developer includes the effect of inhibiting dissolution (etching) of the anodic oxide film on the support, the developability, the effect of inhibiting precipitation and crystal formation, and the gelation during neutralization during waste From the viewpoint of the prevention effect and the like, the amount of SiO ₂ is preferably 0.01 to 1 mol / L, more preferably 0.05 to 0.8 mol / L with respect to the mass of the developer.

  In addition to the above components, the following components can be used in combination in the developer used in the present invention, if necessary. For example, benzoic acid, phthalic acid, p-ethylbenzoic acid, pn-propylbenzoic acid, p-isopropylbenzoic acid, pn-butylbenzoic acid, pt-butylbenzoic acid, pt-butylbenzoic acid Acids, p-2-hydroxyethylbenzoic acid, decanoic acid, salicylic acid, organic carboxylic acids such as 3-hydroxy-2-naphthoic acid; organic solvents such as propylene glycol; other reducing agents, dyes, pigments, water softeners And preservatives.

  The developer used in the present invention preferably has a pH in the range of 10 to 12.5 at 25 ° C, and more preferably in the range of pH 11 to 12.5. Since the developer in the present invention contains the surfactant, even if such a low pH developer is used, excellent developability is exhibited in the non-image area. Thus, by setting the pH of the developing solution to a relatively low value, damage to the image area during development is reduced and the handling property of the developing solution is excellent.

The conductivity x of the developer is preferably 2 <x <30 mS / cm, more preferably 5 to 25 mS / cm.
Here, it is preferable to add an alkali metal salt of an organic acid, an alkali metal salt of an inorganic acid, or the like as a conductivity adjusting agent for adjusting the conductivity.

  The developer can be used as a developer and a development replenisher for the exposed lithographic printing plate precursor, and is preferably applied to an automatic processor. When developing using an automatic developing machine, the developing solution becomes fatigued according to the amount of processing, so that the processing capability may be restored by using a replenishing solution or a fresh developing solution. This replenishment method is also preferably applied to the plate making method of the present invention.

  Furthermore, in order to restore the processing capacity of the developer using an automatic developing machine, it is preferable to replenish by the method described in US Pat. No. 4,882,246. Developers described in JP-A-50-26601, 58-54341, JP-B-56-39464, 56-42860, and 57-7427 are also preferable.

  A more preferable development replenisher contains an oxycarboxylic acid chelating agent having an ability to form a water-soluble chelate compound with aluminum ions, an alkali metal hydroxide, a surfactant, no silicate, and a pH of 11 A development replenisher characterized by being an aqueous solution of ˜13.5. By using such a development replenisher, it has excellent developability and characteristics that do not impair the strength of the image area of the plate material, and is formed by elution of the aluminum support by the alkali of the developer. Precipitation of aluminum is effectively suppressed, and adhesion of stains mainly composed of aluminum hydroxide to the surface of the developing bath roller of the automatic processor and subsequent accumulation of aluminum hydroxide precipitates in the washing bath are reduced. It can be processed stably for a long time.

  The lithographic printing plate thus developed is optionally treated with washing water, a rinsing solution containing a surfactant, etc., and then treated with the above-mentioned plate surface protective solution, and only the plate surface of the lithographic printing plate A plate surface protective layer is also formed on the back surface.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.
The plate surface protective solution 1 to 12 for use in creating the example of plate surface protective solution, the following composition of Table 1-2 (Unit: gram) was prepared according to.
Further, liquid separation was observed for the plate surface protective liquid. Specifically, the plate surface protection liquid was put into a transparent glass bottle, heated to 45 ° C., and the liquid separation state after 3 days was visually evaluated according to the following criteria. The results are shown in the lower part of Tables 1 and 2. ○: No separation has occurred.
Δ: Slightly suspended matter on the surface, but no problem
X: Separated into two layers, causing problems when used after a long period of time.

Preparation of lithographic printing plate A lithographic printing plate precursor having a photosensitive recording layer of each type was provided with backcoat layers 1 to 7 and treated with the plate surface protective liquids 1 to 12 to obtain a lithographic printing plate.
(Backcoat coating composition 1-7 for making backcoat layers 1-7)

^*大日本インキ化学工業（株）
表４：有機高分子化合物組成Ａ〜Ｇの構成（質量％）

Table 3 (unit: grams)

^* Dai Nippon Ink Chemical Co., Ltd.
Table 4: Composition (mass%) of organic polymer compound compositions A to G

Pyrogallol resin

≪Photopolymerization planographic printing plate-1≫
(Production of support)
The surface treatment shown below was performed using a JIS A 1050 aluminum plate having a thickness of 0.30 mm and a width of 1030 mm.
<Surface treatment>
In the surface treatment, the following various treatments (a) to (f) were continuously performed. In addition, after each process and water washing, the liquid was drained with the nip roller.

(A) The aluminum plate was etched at a caustic soda concentration of 26% by mass, an aluminum ion concentration of 6.5% by mass, and a temperature of 70 ° C. to dissolve the aluminum plate at 5 g / m ² . Thereafter, it was washed with water.
(B) A desmut treatment by spraying was performed with a 1% by mass aqueous solution of nitric acid having a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water.

(C) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (including 0.5% by mass aluminum ions and 0.007% by mass ammonium ions) at a temperature of 30 ° C. The AC power source was subjected to an electrochemical surface roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 2 msec until the current value reached a peak from zero and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 250 C / cm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Thereafter, it was washed with water.

(D) The aluminum plate was spray-etched at 35 ° C. with a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.2 g / m ² , The removal of the smut component mainly composed of aluminum hydroxide generated during the chemical surface roughening and the edge portion of the generated pit were dissolved to smooth the edge portion. Thereafter, it was washed with water.

(E) A desmut treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid having a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.
(F) Anodization was performed for 50 seconds at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions), a temperature of 33 ° C., and a current density of 5 (A / dm ² ). Thereafter, it was washed with water. At this time, the weight of the anodized film was 2.7 g / m ² .

  The surface roughness Ra, surface area ratio ΔS, and steepness a45 of the aluminum support thus obtained were Ra = 0.27 (measuring instrument: Surfcom manufactured by Tokyo Seimitsu Co., Ltd., stylus tip diameter 2 microns), respectively. Meter), ΔS = 75%, a45 = 44% (measuring instrument: SPA300 / SPI3800N manufactured by Seiko Instruments Inc.).

(Formation of undercoat layer)
Subsequently, the following undercoat layer-forming coating solution was applied to the same surface of the surface-treated aluminum support with a wire bar and dried at 90 ° C. for 30 seconds. The coating amount was 10 mg / m ² .
<Coating liquid for undercoat layer formation>
-Polymer compound A having the following structure (weight average molecular weight: 10,000) 0.05 g
・ Methanol 27g
・ Ion exchange water 3g

(Formation of photosensitive layer)
The following photosensitive layer forming coating solution A was prepared and applied on the undercoat layer formed as described above using a wire bar. Drying was performed at 125 ° C. for 34 seconds using a warm air dryer. The coating amount after drying was 1.4 g / m ² .
<Photosensitive layer forming coating solution A>
・ Infrared absorber (IR-1) 0.038 g
-Polymerization initiator A (S-1) 0.061g
-Polymerization initiator B (I-1) 0.094g
・ Mercapto compound (E-1) 0.015 g
・ Polymerizable compound (M-1) 0.425 g
(Product name: A-BPE-4 Shin-Nakamura Chemical Co., Ltd.)
-Binder polymer A (B-1) 0.311g
・ Binder polymer B (B-2) 0.250 g
-Binder polymer C (B-3) 0.062g
・ Additive (T-1) 0.079g
-Polymerization inhibitor (Q-1) 0.0012g
・ Ethyl violet (EV-1) 0.021g
・ Fluorine surfactant 0.0081g
(Megafuck F-780-F Dainippon Ink and Chemicals,
Methyl isobutyl ketone (MIBK) 30% by mass solution)
・ Methyl ethyl ketone 5.886g
・ Methanol 2.733g
・ 1-methoxy-2-propanol 5.886 g

  In addition, the infrared absorber (IR-1), polymerization initiator A (S-1), polymerization initiator B (I-1), and mercapto compound (E-1) used for the coating liquid A for forming the photosensitive layer. , Polymerizable compound (M-1), binder polymer A (B-1), binder polymer B (B-2), binder polymer C (B-3), additive (T-1), polymerization inhibitor (Q -1) and the structure of ethyl violet (EV-1) are shown below.

(Formation of lower protective layer)
On the formed photosensitive layer, synthetic mica (Somasif MEB-3L, 3.2% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol (Goselan CKS-50: saponification degree 99 mol%, polymerization degree 300) , Sulfonic acid-modified polyvinyl alcohol, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), surfactant A (manufactured by Nippon Emulsion Co., Ltd., Emalex 710), and surfactant B (Adeka Pluronic P-84: manufactured by Asahi Denka Kogyo Co., Ltd.) ) Was applied with a wire bar and dried at 125 ° C. for 30 seconds with a hot air dryer.
The content ratio of synthetic mica (solid content) / polyvinyl alcohol / surfactant A / surfactant B in this mixed aqueous solution (coating liquid for forming the lower protective layer) was 7.5 / 89/2 / 1.5. The coating amount (the coating amount after drying) was 0.5 g / m ² .

(Formation of upper protective layer)
On the lower protective layer, an organic filler (Art Pearl J-7P, manufactured by Negami Industrial Co., Ltd.), synthetic mica (Somasif MEB-3L, 3.2% aqueous dispersion, manufactured by Coop Chemical Co., Ltd.), polyvinyl alcohol ( L-3266: degree of saponification 87 mol%, degree of polymerization 300, sulfonic acid-modified polyvinyl alcohol Nippon Synthetic Chemical Industry Co., Ltd.), thickener (Serogen FS-B, Daiichi Kogyo Seiyaku Co., Ltd.), high A mixed aqueous solution (a coating solution for forming an upper protective layer) of molecular compound A (the above structure) and a surfactant (manufactured by Nippon Emulsion Co., Ltd., Emalex 710) is applied with a wire bar, and 125 ° C. using a hot air dryer. For 30 seconds.
The content ratio of the organic filler / synthetic mica (solid content) / polyvinyl alcohol / thickener / polymer compound A / surfactant in the mixed aqueous solution (upper protective layer forming coating solution) is 4.7 / 2. /8/67.4/18.6/2.3/4.2 (mass%), and the coating amount (the coating amount after drying) was 1.2 g / m ² .

(Formation of back coat layer and treatment with plate surface protection liquid)
On the surface opposite to the side provided with the protective layer, various backcoat coating liquid compositions 1 to 7 shown in Table 3 were applied with a wire bar and dried at 100 ° C. for 70 seconds to obtain a backcoat layer containing an organic polymer compound. It was. The coating amount was 0.46 g / m ² .
The lithographic printing plate precursor thus obtained is conveyed from the setting part to a Trend setter 3244 manufactured by Creo by a loader, and a 50% flat screen image is output at a resolution of 2400 dpi, output 7 W, external drum rotation speed 150 rpm, plate surface energy 110 mJ / cm ^2. And exposed. After the exposure, neither heat treatment nor water washing treatment was performed, and development was performed at a conveyance speed (line speed) of 2 m / min and a development temperature of 30 ° C. using an automatic developing machine LP-1310HII manufactured by FUJIFILM Corporation. The developer is a 1: 4 water dilution of DH-N, the developer replenisher is 1: 1.4 water diluted of FCT-421, and the plate surface protection solution is a plate surface protection solution 1 having the composition shown in Tables 1-2. ~ 12 were used. Thus, a lithographic printing plate provided with a plate surface protective layer having a coating amount of 0.25 g / m ² on the backcoat layer was obtained.

≪Thermal positive lithographic printing plate≫
[Production of support]
(Aluminum plate)
Si: 0.06 mass%, Fe: 0.30 mass%, Cu: 0.025 mass%, Mn: 0.001 mass%, Mg: 0.001 mass%, Zn: 0.001 mass%, Ti: It contains 0.03% by mass, and the balance is prepared by using an aluminum alloy of Al and inevitable impurities. After the molten metal treatment and filtration, an ingot having a thickness of 500 mm and a width of 1200 mm is obtained by a DC casting method. Produced. After the surface was shaved with a chamfering machine with an average thickness of 10 mm, it was kept soaked at 550 ° C. for about 5 hours, and when the temperature dropped to 400 ° C., rolling with a thickness of 2.7 mm using a hot rolling mill A board was used. Furthermore, after performing heat processing using a continuous annealing machine at 500 degreeC, it finished by cold rolling to 0.24 mm in thickness, and obtained the aluminum plate of JIS1050 material. The obtained aluminum had an average crystal grain size with a minor axis of 50 μm and a major axis of 300 μm. After making this aluminum plate width 1030mm, it used for the surface treatment shown below.

(surface treatment)
For the surface treatment, the following various treatments (a) to (k) were continuously performed. In addition, after each process and water washing, the liquid draining was performed with the nip roller.
(A) Mechanical surface roughening treatment Using an apparatus as shown in FIG. 1, a suspension of a polishing agent (pumice) having a specific gravity of 1.12 and water is supplied as a polishing slurry to the surface of the aluminum plate. However, a mechanical surface roughening treatment was performed with a rotating roller-like nylon brush. In FIG. 1, 1 is an aluminum plate, 2 and 4 are roller brushes, 3 is a polishing slurry, and 5, 6, 7 and 8 are support rollers. The average particle size of the abrasive was 30 μm, and the maximum particle size was 100 μm. The material of the nylon brush was 6 · 10 nylon, the hair length was 45 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus with respect to the load before the brush roller was pressed against the aluminum plate. The rotating direction of the brush was the same as the moving direction of the aluminum plate. The rotation speed of the brush was 200 rpm.

(B) Alkali etching treatment The aluminum plate obtained above was subjected to an etching treatment by spraying using an aqueous solution having a caustic soda concentration of 2.6% by mass, an aluminum ion concentration of 6.5% by mass and a temperature of 70 ° C. / M ² dissolved. Then, water washing by spraying was performed.
(C) Desmutting treatment The desmutting treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid at a temperature of 30 ° C. (containing 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut treatment was a waste liquid from a process of performing an electrochemical surface roughening treatment using alternating current in a nitric acid aqueous solution.

(D) Electrochemical roughening treatment An electrochemical roughening treatment was carried out continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 10.5 g / L aqueous solution of nitric acid (containing 5 g / L of aluminum ions and 0.007% by mass of ammonium ions) at a liquid temperature of 50 ° C. The AC power supply waveform is the waveform shown in FIG. 2, the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, a trapezoidal rectangular wave AC is used with the carbon electrode as the counter electrode An electrochemical roughening treatment was performed. Ferrite was used for the auxiliary anode. The electrolytic cell used was the one shown in FIG.
The current density was 30 A / dm ² at the peak current value, and the amount of electricity was 220 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.

(E) Alkaline etching treatment The aluminum plate was subjected to etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass to dissolve the aluminum plate by 0.50 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(F) Desmut treatment Desmut treatment was performed by spraying with a 15% by weight aqueous solution of nitric acid at a temperature of 30 ° C. (containing 4.5% by weight of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used in the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in the nitric acid aqueous solution.

(G) Electrochemical roughening treatment An electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 5.0 g / L aqueous solution (containing 5 g / L of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform is the waveform shown in FIG. 2, and the time TP until the current value reaches the peak from zero is 0.8 msec, the duty ratio is 1: 1, and the trapezoidal square wave AC is used to connect the carbon electrode. Electrochemical roughening treatment was performed as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was the one shown in FIG.
The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 50 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode. Then, water washing by spraying was performed.

(H) Alkaline etching treatment The aluminum plate was subjected to an etching treatment at 32 ° C. using an aqueous solution having a caustic soda concentration of 26 mass% and an aluminum ion concentration of 6.5 mass%, and the aluminum plate was dissolved at 0.10 g / m ² . Removes the smut component mainly composed of aluminum hydroxide that was generated when electrochemical roughening treatment was performed using the alternating current of the previous stage, and also melted the edge part of the generated pit to smooth the edge part. did. Then, water washing by spraying was performed.
(I) Desmutting treatment A desmutting treatment by spraying was performed with a 25% by weight aqueous solution of sulfuric acid at a temperature of 60 ° C. (containing 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(J) Anodizing treatment Using an anodizing apparatus having a structure shown in FIG. 4 (first and second electrolysis unit length 6 m each, first and second feeding unit length 3 m each, first and second feeding unit length 2.4 m each) Anodizing was performed. Sulfuric acid was used as the electrolytic solution supplied to the first and second electrolysis units. All electrolytes had a sulfuric acid concentration of 50 g / L (containing 0.5 mass% of aluminum ions) and a temperature of 20 ° C. Then, water washing by spraying was performed.
In the anodizing device, currents from the power supply 67a and the power supply 67b flow to the first power supply electrode 65a provided in the first power supply section 62a, flow to the aluminum plate 11 through the electrolytic solution, and the first electrolysis section 63a. Thus, an anodic oxide film is formed on the surface of the aluminum plate 11, passes through the electrolytic electrodes 66a and 66b provided in the first electrolysis part 63a, and returns to the electrodes 67a and 67b.
The amount of electricity fed from the power sources 67a and 67b to the first feeding unit 62a is equal to the amount of electricity fed from the power sources 67c and 67d to the second feeding unit 62b, and the first electrolysis unit 63a and the second electrolysis unit Both current densities at 63b were about 30 A / dm ² . In the 2nd electric power feeding part 62b, it electrically fed through the oxide film surface of 1.35 g / m < ² > produced | generated by the 1st electrolysis part 63a. The final oxide film amount was 2.7 g / m ² .

(K) Alkali metal silicate treatment The aluminum support obtained by anodizing treatment is immersed in a treatment tank of a 1% by mass aqueous solution of sodium silicate No. 3 at a temperature of 30 ° C. for 10 seconds. Acid salt treatment (silicate treatment) was performed. Thereafter, washing with water using well water was performed to obtain a support subjected to a surface silicate hydrophilization treatment. On the aluminum support after the alkali metal silicate treatment obtained as described above, an undercoat solution having the following composition was applied and dried at 80 ° C. for 15 seconds to form a coating film. The coating amount of the coating film after drying was 15 mg / m ² .

<Undercoat liquid composition>
・ The following compound 0.3g
・ Methanol 100g
・ Water 1g

[Formation of multi-layer recording layer]
After applying the lower layer coating solution 1 having the following composition on the obtained undercoated support with a bar coater so that the coating amount becomes 0.85 g / m ² , the coating is dried at 160 ° C. for 44 seconds and immediately 17 to 20 The support was cooled with cold air at a temperature of 35 ° C.
Thereafter, a coating solution 1 for the upper layer having the following composition was applied by a bar coater so that the coating amount was 0.22 g / m ² , dried at 148 ° C. for 25 seconds, and further slowly cooled with air at 20 to 26 ° C. A recording layer was provided.

<Lower layer coating solution 1>
-Copolymer of N- (P-aminosulfonylphenyl) methacrylamide and methyl methacrylate 2.13 g
(Described in Synthesis Example 1 of European Patent 33030239)
・ Cyanine dye A (the following structure) 0.134 g
・ 4,4'-bishydroxyphenylsulfone 0.126g
・ Tetrahydrophthalic anhydride 0.190g
・ 0.008 g of p-toluenesulfonic acid
・ 3-Methoxy-4-diazodiphenylamine hexafluorophosphate
0.032g
・ The counter ion of ethyl violet is changed to 6-hydroxynaphthalenesulfonic acid
0.0781g
・ Polymer 1 (the following structure) 0.035g
・ Methyl ethyl ketone 25.41g
・ 1-methoxy-2-propanol 12.97g
・ Γ-butyrolactone 13.18g

<Upper layer coating solution 1>
・ M, p-cresol novolak 0.3479g
(M / p ratio = 6/4, weight average molecular weight 4500, containing unreacted cresol 0.8% by mass)
-Polymer 3 (the following structure MEK 30% solution) 0.1403g
・ Cyanine dye A (the above structure) 0.0192 g
・ Polymer 1 (the above structure) 0.015 g
-Polymer 2 (the following structure) 0.00328g
・ Quaternary ammonium salt (the following structure) 0.0043g
・ Surfactant (polyoxyethylene sorbite fatty acid ester
HLB8.5, GO-4 manufactured by Nikko Chemicals Co., Ltd.) 0.008g
・ Methyl ethyl ketone 6.79g
・ 1-methoxy-2-propanol 13.07 g

(Formation of back coat layer and treatment with plate surface protection liquid)
On the surface opposite to the side on which the photosensitive recording layer was provided, the backcoat coating solution composition 3 shown in Table 3 was coated with a wire bar and dried at 100 ° C. for 70 seconds to obtain a backcoat layer containing an organic polymer compound. . The coating amount was 0.46 g / m ² .
The lithographic printing plate precursor thus obtained was drawn with a test pattern in the form of an image by changing the exposure energy with a Trend setter manufactured by Creo. Thereafter, Fuji Film Co., Ltd. was charged with developer DT-2 (diluted to a conductivity of 43 mS / cm) manufactured by Fuji Film Co., Ltd. and plate surface protective solutions 1-12 having the compositions shown in Tables 1-2. A lithographic printing plate provided with a plate surface protective layer was obtained after development at a development temperature of 30 ° C. and a development time of 12 seconds using PS processor LP1310HII. The coating amount of the plate surface protective layer on the back coat layer was 0.25 g / m ² .

≪Photopolymerization planographic printing plate 2≫
(Preparation of aluminum support)
An aluminum plate having a thickness of 0.3 mm was etched by being immersed in 10% by mass sodium hydroxide at 60 ° C. for 25 seconds, washed with running water, neutralized and washed with 20% by mass nitric acid, and then washed with water. This was subjected to an electrolytic surface roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current at an anode time electricity of 300 coulomb / dm ² . Subsequently, after dipping in a 1% by mass aqueous sodium hydroxide solution at 40 ° C. for 5 seconds and then in a 30% by mass sulfuric acid aqueous solution and desmutting at 60 ° C. for 40 seconds, the current density in a 20% by mass sulfuric acid aqueous solution was 2A / current density. Anodization was performed for 2 minutes so that the thickness of the anodized film was 2.7 g / m ² under the condition of dm ² . When the surface roughness was measured, it was 0.3 μm (Ra display according to JIS B0601).

(Formation of intermediate layer)
The aluminum plate thus treated was first coated with the next intermediate layer solution using a bar coater and then dried at 80 ° C. for 20 seconds. A coating amount of the intermediate layer after drying was 10 mg / m ^2.
Intermediate layer liquid, the following sol liquid 100g
・ Methanol 900g
Sol solution / Phosmer PE (Unichemical Co., Ltd.) 5g
・ Methanol 45g
・ Water 10g
・ 85% phosphoric acid 5g
・ Tetraethoxysilane 20g
・ 3-Methacryloxypropyltrimethoxysilane 15g

(Formation of photosensitive layer)
On this, a high-sensitivity photopolymerizable composition P-1 having the following composition was applied so that the dry coating mass was 1.4 g / m ² and dried at 100 ° C. for 1 minute to form a photosensitive recording layer. .
Photopolymerizable composition P-1
Urethane monomer (M-1) 4.20 parts by weight Polyurethane binder (B-1) 1.80 parts by weight Polyurethane binder (B-2) 1.80 parts by weight Sensitizing dye (C-1) 21 parts by mass, polymerization initiator (D-1) 0.81 parts by mass, chain transfer agent (E-1) 0.3 parts by mass, ε-phthalocyanine dispersion (25% by mass dispersion) 0.76 parts by mass Fluoro-based nonionic surfactant Megafac F780 0.05 parts by mass (Dainippon Ink Chemical Co., Ltd.)
・ Methyl ethyl ketone 58 parts by mass ・ Propylene glycol monomethyl ether acetate 53 parts by mass

(Formation of oxygen barrier layer)
Polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 500), polyvinylpyrrolidone (manufactured by BASF Corp., rubiscol K-30), and the fluorosurfactants described in the table below are formed on the photosensitive recording layer surface. 1.0% by mass and 2% by mass of a surfactant aqueous solution, Pionein D230 (manufactured by Takemoto Yushi Co., Ltd.) were applied with a wire bar, and dried at 125 ° C. for 75 seconds with a warm air dryer. The coating amount (the coating amount after drying) was 2.45 g / m ² .

(Formation of back coat layer and treatment with plate surface protection liquid)
On the surface opposite to the side on which the oxygen blocking layer is provided, the backcoat coating solution composition 3 shown in Table 3 is coated with a wire bar and dried at 100 ° C. for 70 seconds to obtain a backcoat layer containing an organic polymer compound. It was. The coating amount was 0.46 g / m ² .
The obtained lithographic printing plate precursor was adjusted with a plate setter Vx9600CTP (light source wavelength: 405 nm) manufactured by Fuji Film Co., Ltd. so that the exposure amount on the photosensitive lithographic printing plate was 0.05 mJ / cm ² , and 100 lpi 1, 2, 3, 4, 5, and 6% of net images were drawn. Thereafter, using a G & J PS processor IP850HD charged with an alkali developer having the following composition and the plate surface protection solutions 1 to 12 shown in Tables 1-2, the preheat temperature was 115 ° C., the solution temperature was kept at 25 ° C., and the development time was 28. After development in seconds, a lithographic printing plate provided with a plate surface protective layer having a coating amount of 0.25 g / m ² on the backcoat layer was obtained.
Alkali developer composition / Potassium hydroxide 0.15g
・ Polyoxyethylene naphthyl ether (n = 13) 5.0 g
・ Chillest 400 (Chelest Co., Ltd. chelating agent) 0.1 g
・ Water 94.75g

≪Conventional positive type lithographic printing version≫
An aluminum plate having a thickness of 0.30 mm was grained with a nylon brush and a 400 mesh Bamiston water suspension, and then thoroughly washed with water. Etching was performed by immersing in 10% sodium hydroxide at 70 ° C. for 60 seconds, washing with running water, neutralizing and washing with 20% HNO ₃ , and washing with water. This was subjected to an electrolytic surface roughening treatment in a 1% nitric acid aqueous solution with an electric quantity at the time of anode of 260 coulomb / dm ² using a sinusoidal alternating current under the condition of VA = 12.7V. When the surface roughness was measured, it was 0.55 μ ( _Ra indication). Subsequently, after dipping in a 30% aqueous solution of H ₂ SO _{4 and} desmutting at 55 ° C. for 2 minutes, the thickness in the aqueous solution of 20% H ₂ SO ₄ is 1.6 g / m ² at a current density of 2 A / dm ² . The substrate was prepared by anodizing as described above.
An undercoat liquid (A) having the following composition was applied to the surface of the substrate thus treated and dried at 80 ° C. for 30 seconds. The coating amount after drying was 10 mg / m ² .
Undercoat liquid (A)
β-Alanine 0.05g
Triethanolamine hydrochloride 0.05g
40 g of methanol
60 g of pure water
In this way, a substrate (I) was prepared.

Next, 25 ml / m ² of the following photosensitive solution was applied on the substrate (I) by rod coating and dried at 100 ° C. for 1 minute to obtain a photosensitive recording layer. The coating amount after drying was about 1.0 g / m ² .
[Photosensitive solution]
1.90 g of esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) 0.90 g
Cresol-formaldehyde novolak resin (meta, para ratio: 6 to 4, weight average molecular weight 3,000, number average molecular weight 1,000, containing 0.7% of unreacted cresol)
1.60g
m-cresol-formaldehyde novolak resin (weight average molecular weight 1,700, number average molecular weight 600, containing 1% of unreacted cresol) 0.3 g
Poly [N- (p-aminosulfonylphenyl) acrylamide-co-normal butyl acrylate-co-diethylene glycol monomethyl ether methacrylate] (molar ratio of each monomer is 40:40:20, weight average molecular weight 40,000, number average molecular weight in order) 20,000) 0.2g
p-normal octylphenol-formaldehyde resin 0.02 g
(Described in US Pat. No. 4,123,279)
Naphthoquinonediazide-1,2-diazide-4-sulfonic acid chloride
0.01g
Tetrahydrophthalic anhydride 0.02g
Benzoic acid 0.02g
Compound described in JP-A-63-58440 0.02 g
N- (1,2-naphthoquinone-2-diazide-4-sulfonyloxy) -cyclohexane-1,2-dicarboxylic acid imide 0.01 g
0.05 g of a dye obtained by changing the counter anion of Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.] to 1-naphthalenesulfonic acid
MegaFuck F-176 (Fluorine surfactant manufactured by Dainippon Ink & Chemicals, Inc.)
0.01g
Methyl ethyl ketone 55g

(Formation of back coat layer and treatment with plate surface protection liquid)
On the surface opposite to the side where the photosensitive recording layer is provided, the backcoat coating solution composition 3 shown in Table 3 is coated with a wire bar and dried at 100 ° C. for 70 seconds to obtain a backcoat layer containing an organic polymer compound. It was. The coating amount was 0.46 g / m ² .
The lithographic printing plate thus obtained was used as a light source and a 2 KW metal halide lamp (Idle Fin 2000 manufactured by Iwasaki Electric Co., Ltd.) was used, and the exposure time was adjusted so that 10 μm was reproduced with a foggy PMSK value after 8.0 mW / cm ² development. After the exposure, the plain image property of the printing plate was visually evaluated, and a 5.26% aqueous solution of sodium silicate (pH = 12.7) having a SiO ₂ / Na ₂ O molar ratio of 1.74 as a developer. The plate surface protective layers 1 and ² having a coating amount of 0.25 g / m ² on the backcoat layer were processed with an automatic developing machine PS-1310VII manufactured by Fuji Film, charged with plate surface protective solutions 1 to 12 having the compositions shown in Tables 1 and ² . A lithographic printing plate having 12 was obtained.

The backcoat layer containing the organic polymer compound thus obtained and the planographic printing plate having the plate surface protective layer thereon were evaluated by the following methods with respect to the following items.
Adhesion between the backcoat layer and the plate surface protective layer When a strong adhesive tape is applied to the plate surface protective layer applied on the backcoat layer and then peeled off, the film is peeled off between the backcoat layer and the plate surface protective layer. The peel strength at this time (that is, the adhesion between the backcoat layer and the plate surface protective layer) was measured with a Tensilon tensile tester. The relationship between the failure and the numerical value where the exfoliated material contaminated the post-process was confirmed by a separate practical test. The judgment criteria are as follows.
0.25 N / cm or more: No peeling occurs.
0.12 N / cm or more and less than 0.25 N / cm: Slight peeling but no problem.
Less than 0.12 N / cm: Separation occurs, contaminating subsequent processes and causing failure.
When printing ink payment number lithographic printing plate mounted on an offset printing machine, and start printing from wearing the ink to the plate surface over the entire surface, and compared the number of up to normal printed matter obtained. A smaller number is better because it does not consume wasted paper.
The results are shown in the table below.

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table 11

Table 12

Table 13

Table 14

1 schematically shows an apparatus for performing a mechanical surface roughening treatment on an aluminum support. The alternating current power supply waveform in the electrochemical roughening process of an aluminum support body is represented. The structure of the electrolytic cell which performs the electrochemical roughening process of an aluminum support body is represented. 1 schematically represents an anodizing apparatus.

Claims (7)

A lithographic printing plate precursor having a photosensitive recording layer on one side of an aluminum support and having a back coat layer containing an organic polymer compound on the aluminum support opposite to the side having the photosensitive recording layer, A plate making method in which an imagewise exposure and development treatment are carried out, followed by treatment with a plate surface protective solution containing a copolymer represented by the following general formula (1).

(In the formula, m and n represent a copolymerization ratio, where m + n is 100, m is in the range of 10 to 90, and R is at least 1 selected from the group consisting of —OH, —OCH ₃ , and —OCOCH _3. Seeds.)   The plate making method according to claim 1, wherein the organic polymer compound contained in the back coat layer contains an epoxy resin.   The plate making method according to claim 2, wherein the organic polymer compound contained in the backcoat layer further contains rosin.   4. The plate making method according to claim 2, wherein the organic polymer compound contained in the back coat layer further contains a resin having a phenolic hydroxyl group.   In the copolymer shown by General formula (1), m is 55 to 75, The plate-making method of any one of Claims 1-4 characterized by the above-mentioned. In the copolymer represented by the general formula (1), characterized in that R is -OCOCH _3, a method for making any one of claims 1 to 5.   The photosensitive recording layer contains an infrared absorber, a polymerization initiator, a monomer having two or more phenyl groups substituted with vinyl groups in the molecule, and a polymer having phenyl groups substituted with vinyl groups in the side chain. The plate making method of any one of Claims 1-6 characterized by the above-mentioned.

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