JP2009210639A - Developing liquid for planographic printing plate and platemaking method of planographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing liquid for a planographic printing plate and a platemaking method of a planographic printing plate, in which the developing liquid can be developed within an acidic to neutral range and solving a problem of a developing property upon developing, and a problem of process unevenness caused by an eluted component from a photosensitive material. <P>SOLUTION: The developing liquid for the planographic printing plate contains an amphoteric surfactant expressed by a formula (I), a water-soluble polymer compound, and furthermore an azole compound, and has a pH of 2 to 8. The platemaking method for the planographic printing plate is carried out by using the liquid. In the formula (I), R1 and R2 independently represent H or an alkyl group, respectively; R3 represents an alkyl group or a group having an ethylene oxide; and A represents a group containing a carboxylic acid anion, a sulfonic acid anion or a phosphonic acid anion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lithographic printing plate development processing solution and a lithographic printing plate making method, and in particular, a lithographic plate which can be processed in an acidic to low alkaline region, can be developed in an acidic region, and has good development residue dispersion stability. The present invention relates to a developing solution for a printing plate and a method for making a lithographic printing plate.

In general, a lithographic printing plate comprises an oleophilic image area that receives ink in the printing process and a hydrophilic non-image area that receives dampening water. Lithographic printing uses the property that water and printing ink repel each other, so that the oleophilic image area of the lithographic printing plate is the ink receiving area, the hydrophilic non-image area is dampened with the water receiving area (ink non-receiving area). ), A difference in ink adhesion is caused on the surface of the lithographic printing plate, and after ink is applied only to the image area, the ink is transferred to a printing medium such as paper and printed.
In order to produce this lithographic printing plate, conventionally, a lithographic printing plate precursor (PS plate) in which an oleophilic photosensitive resin layer (image recording layer) is provided on a hydrophilic support has been widely used. Usually, the lithographic printing plate precursor is exposed through an original image such as a lithographic film, and then the image portion of the image recording layer is left, and the other unnecessary image recording layer is removed with an alkaline developer or organic A lithographic printing plate is obtained by dissolving and removing with a solvent and exposing the surface of the hydrophilic support to form a non-image area.

  As described above, in the plate making process of the conventional lithographic printing plate precursor, a step of dissolving and removing an unnecessary image recording layer with a developer or the like is necessary after exposure, but it is closer to the neutral range in terms of environment and safety. Treatment with a developing solution and a small amount of waste liquid are cited as problems. In particular, in recent years, disposal of waste liquid discharged with wet processing has become a major concern for the entire industry due to consideration for the global environment, and the demand for solving the above-mentioned problems has become stronger.

  On the other hand, in recent years, digitization technology for electronically processing, storing, and outputting image information by a computer has become widespread, and various new image output methods corresponding to such digitization technology will be put into practical use. It is becoming. Along with this, digitized image information is carried by high-convergence radiation such as laser light, and the lithographic printing plate precursor is scanned and exposed with that light, directly without using a lithographic film. Computer-to-plate (CTP) technology has been attracting attention. Accordingly, obtaining a lithographic printing plate precursor adapted to such a technique is one of the important technical issues.

  As mentioned above, the low alkali level of the developer and the simplification of the processing process are more strongly desired than ever in terms of consideration for the global environment, space saving, and low running cost. It has become to. However, as described above, the development processing step generally comprises three steps: development with an alkaline aqueous solution having a pH of 10 or higher, followed by flowing an alkaline agent in a washing bath, and then processing with a gum solution mainly composed of a hydrophilic resin. For this reason, the automatic developing machine itself takes up a large space, and there are still problems in terms of environment and running cost, such as a problem of developing waste liquid, washing waste liquid and gum waste liquid.

On the other hand, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-91016) proposes a developing method using an alkaline solution containing a nonionic surfactant having a pH of 10 to 12.5. The product contains an alkali-soluble polymer, and there is a problem that development cannot be performed at a pH lower than the above specified value. Further, for example, Patent Document 2 (Japanese Patent No. 2938397) discloses a lithographic printing plate precursor in which an image forming layer in which hydrophobic thermoplastic polymer particles are dispersed in a hydrophilic binder is provided on a hydrophilic support. Are listed. This lithographic printing plate precursor is formed by image exposure using an infrared laser to form an image by coalescence of hydrophobic thermoplastic polymer particles by heat, and is then mounted on a cylinder of a printing machine, fountain solution and / or On-press development is possible with ink.

In this way, the method of forming an image by merging by simple thermal fusion of fine particles shows good on-press developability, but the image strength (adhesion with the support) is extremely weak and the printing durability is insufficient. Had the problem of being.
Further, for example, Patent Document 3 (WO2007 / 057336) describes a method of treating a photopolymerization type plate with a treatment liquid containing a water-soluble resin component. In particular, polyvinyl alcohol (PVA) is used for a protective layer of the plate. Is used, there is a problem in that the PVA is eluted in the processing solution, thereby causing processing unevenness on the image of the printing plate. This problem of processing unevenness becomes more serious when a large amount of surfactant is present in the processing solution, which has been a serious failure in running processing.

JP 2002-91016 A Japanese Patent No. 2938397 International Publication No. 07/057336 Pamphlet

As described above, the development system using an alkaline agent is a problem in terms of environmental problems, replenishment solution to compensate for the decrease in pH due to absorption of carbon dioxide, equipment, and accompanying increase in the amount of waste liquid, running of the developer solution There was a cost problem.
In general, in the development in the acidic to low alkali region, the components of the image recording layer in the non-image area once removed are hardly dispersed stably in the developer, and particularly when PVA is used for the protective layer. There was also a problem of uneven processing.
Accordingly, the object of the present invention is to overcome the above-mentioned drawbacks of the conventional techniques, develop in the acidic to neutral range, and develop in question at that time, and further to the components eluted from the photosensitive material. An object of the present invention is to provide a lithographic printing plate development processing solution and a lithographic printing plate making method that have overcome the problem of uneven processing.

As a result of diligent study to achieve the above object, the present inventor treated the lithographic printing plate precursor with an aqueous solution containing a specific surfactant, a water-soluble polymer compound, and an azole compound after image exposure. In addition, the present invention has been achieved by obtaining a developing solution that has excellent developability in an acidic to low alkaline region and that is excellent in reducing processing unevenness in processing running.
That is, the present invention is as follows.

  1) A developing solution for a lithographic printing plate comprising an amphoteric surfactant represented by the following formula (I), a water-soluble polymer compound, and an azole compound, and having a pH of 2 to 8.

(In the formula (I), R 1 and R 2 each independently represent H or an alkyl group, R 3 represents an alkyl group or a group containing ethylene oxide, and A represents a carboxylate anion, a sulfonate anion, or a phosphone. It is a group containing an acid anion.)
2) The azole compound is α- (4-chlorophenyl) -α- (1-cyclopropylethyl) -1H-1,2,4-triazole-1-ethanol, -α- [2- (4-chlorophenyl) Ethyl] -α- (1,1-dimethylethyl) -1H-1,2,4-triazole-1-ethanol and 1-[[2- (2,4-dichlorophenyl) -4-n-propyl-1, The developing solution for lithographic printing plate as described in 1) above, which is selected from azole compounds consisting of 3-dioxolan-2-yl] methyl] -1H-1,2,4-triazole.
3) After the lithographic printing plate precursor having the image recording layer and the protective layer containing polyvinyl alcohol on the support is exposed imagewise to cure the image recording layer in the exposed portion, the above 1) or 2) A lithographic printing plate making method, wherein the development is performed with the processing solution described in 1.
4) The method for making a lithographic printing plate as described in 3) above, wherein the polyvinyl alcohol is acid-modified polyvinyl alcohol.

  According to the present invention, the development processing solution can be developed with an aqueous solution having a pH of 2 to 8 by containing the compound represented by the formula (I) as a specific surfactant, and is based on carbon dioxide gas. A lithographic printing plate having a constant quality can be made by a developer having no deterioration and always having a constant developing property. Further, it is advantageous in terms of developer replenishment amount, waste liquid amount reduction, running cost, and environmental aspects, and further overcomes the problem of processing unevenness due to components eluted from the light-sensitive material. The plate making method can be provided.

The lithographic printing plate developing solution and the planographic printing plate making method of the present invention will be described below.
[Development solution]
The lithographic printing plate development processing solution of the present invention (hereinafter also simply referred to as processing solution) contains a compound represented by the following formula (I) and has a pH of 2 to 8. The compound represented by the formula (I) is a so-called amphoteric surfactant.

(In the formula (I), R 1 and R 2 each independently represent H or an alkyl group, R 3 represents an alkyl group or a group containing ethylene oxide, and A represents a carboxylate anion, a sulfonate anion, or a phosphone. It is a group containing an acid anion.)
The molecular weight of the compound represented by formula (I) is generally 150 to 2000, preferably 200 to 1000.

The ethylene oxide in the group having an ethylene oxide as _{R3 - (CH 2 CH 2 O} ) n- (n is an integer of 1 or more, preferably 2 to 20) means.
The group containing ethylene _{oxide, - (CH 2 CH 2 O} ) a monovalent group containing n-, _{e.g., - (CH 2 CH 2 O} ) n-H, - (CH 2 CH 2 O ) _n-CH 3, - and the like _{(CH 2 CH 2 O) n} -CH 2 CH 3.

  The group containing a carboxylate anion, sulfonate anion, or phosphonate anion as A is a group in which an arbitrary monovalent group such as an alkyl group is substituted with a carboxylate anion, a sulfonate anion, or a phosphonate anion. Or a carboxylic acid anion, a sulfonic acid anion, or a phosphonic acid anion itself. A group containing a carboxylate anion as A is particularly preferred.

In addition, when A is a group containing a phosphonate anion, the phosphonate anion is a divalent anion, and therefore the compound represented by the formula (I) is a monovalent anion. In this case, any counter cation may be used, and examples thereof include monovalent cations such as Na, K, or NH ₄ .

  Although it does not specifically limit as a compound (henceforth a surfactant) represented by the said formula (I), A typical thing is shown below.

(.X wherein the .R14 representing the .R13 alkyl group represented by R11 and R12 are each independently H or an alkyl group or an ethylene oxide group, which represents an alkylene group represents Na, K, or NH _4. )

In the compound corresponding to the above formula (I), when the total carbon number is increased, the hydrophobic portion is increased, and when it is difficult to dissolve in an aqueous developer, an organic solvent that assists dissolution, an alcohol or other dissolution aid in water. By mixing, dissolution can be improved.
From the viewpoint of solubility in an aqueous developer, the total number of carbon atoms R11 to R14 in the compound represented by the above general formula is preferably 10 to 40, more preferably 12 to 30. Here, when R11 to R13 described above are alkyl groups or R14 is an alkylene group, the structure thereof may be linear or branched.
The carbon number of R11 to R14 in the compound represented by the above general formula is affected by the material used for the image recording layer, particularly the binder. In the case of a binder having a high degree of hydrophilicity, the carbon number of R11 to R14 tends to be relatively small, and when the binder used has a low degree of hydrophilicity, a carbon number of R11 to R14 is preferably large.
Typical compounds include those shown below.

  In the development processing solution of the present invention, the compound represented by the general formula (I) usually exhibits an effect when the total amount is 2% by mass, and preferably 5% by mass or more. In view of erosion of the developing bath member, the content is preferably 20% by mass or less.

Next, the azole compound used in the present invention will be described.
The azole compound used in the present invention is a compound having at least one azole skeleton, and the molecular weight is generally 70 to 600, preferably 100 to 400.
As azole compounds, α- (4-chlorophenyl) -α- (1-cyclopropylethyl) -1H-1,2,4-triazole-1-ethanol (generic name: cyproconazole), (±)- α- [2- (4-Chlorophenyl) ethyl] -α- (1,1-dimethylethyl) -1H-1,2,4-triazole-1-ethanol (generic name: tebuconazole) and 1-[[2- (2,4-Dichlorophenyl) -4-n-propyl-1,3-dioxolan-2-yl] methyl] -1H-1,2,4-triazole (generic name: propiconazole) is preferably used.
The content of these azole compounds in the treatment liquid is preferably 0.01 to 4% by mass, more preferably 0.02 to 3% by mass.

The development processing solution of the present invention contains a water-soluble polymer compound in addition to the specific surfactant. Therefore, the desensitization process can be performed simultaneously with the development process.
The water-soluble polymer compound used in the present invention means a polymer compound that dissolves 1% by mass or more in 25 ° C. water.
Here, as the water-soluble polymer compound used, soybean polysaccharide, modified starch, gum arabic, dextrin, fiber derivative (eg, carboxymethylcellulose, carboxyethylcellulose, methylcellulose, etc.) and modified products thereof, pullulan, polyvinyl alcohol and the like Derivatives, polyvinylpyrrolidone, polyacrylamide and acrylamide copolymers, vinyl methyl ether / maleic anhydride copolymers, vinyl acetate / maleic anhydride copolymers, styrene / maleic anhydride copolymers, and the like.
As said soybean polysaccharide, what is known conventionally can be used, for example, there exists a brand name Soya Five (made by Fuji Oil Co., Ltd.) as a commercial item, and the thing of various grades can be used. What can be preferably used is one in which the viscosity (25 ° C.) of a 10 mass% aqueous solution is in the range of 10 to 100 mPa / sec.

  As said modified starch, what is shown by the following general formula (III) is preferable. As the starch represented by the general formula (III), any starch such as corn, potato, tapioca, rice and wheat can be used. These starch modifications can be made by a method of decomposing in the range of 5 to 30 glucose residues per molecule with an acid or an enzyme, and further adding oxypropylene in an alkali.

(In the formula, the degree of etherification (degree of substitution) is in the range of 0.05 to 1.2 per glucose unit, n represents an integer of 3 to 30, and m represents an integer of 1 to 3.)

  Among the water-soluble polymer compounds, soybean polysaccharides, modified starch, gum arabic, dextrin, carboxymethyl cellulose, polyvinyl alcohol and the like are particularly preferable.

  Two or more water-soluble polymer compounds can be used in combination. The content of the water-soluble polymer compound in the treatment liquid is preferably 0.1 to 20% by mass, and more preferably 0.5 to 10% by mass.

  In the present invention, the water-soluble polymer compound can be contained in a development solution having a specific pH containing the specific surfactant and subjected to a desensitization process simultaneously with the development process. Further, in order to further ensure the desensitization treatment, it may be used in contact with an aqueous solution containing the water-soluble polymer compound after the development treatment with this development treatment solution.

The treatment liquid of the present invention may contain a silicone compound. A silicone compound means organopolysiloxanes.
In the present invention, as the silicone compound, dimethylpolysiloxane is mixed with water together with an anionic surfactant to form an O / W emulsion, and the alkoxypoly (ethyleneoxy) siloxane shown below is similarly used as an emulsion. Used. These silicone compounds work to improve wettability and prevent processing unevenness when a plate is continuously processed by an automatic processor. The amount of the silicone compound added to the development processing solution is 0.0001 to 1.0% by mass, more preferably 0.001 to 0.1% by mass with respect to the development processing solution.
When the content of the silicone compound is less than 0.0001% by mass, the defoaming effect is insufficient, and when it exceeds 1.0% by mass, the stain resistance in printing deteriorates.

In addition to the above, the treatment liquid of the present invention may contain a wetting agent, preservative, chelate compound, organic acid, organic solvent, inorganic acid, inorganic salt, and the like.

  As the wetting agent, ethylene glycol, propylene glycol, triethylene glycol, butylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diglycerin and the like are preferably used. These wetting agents may be used alone or in combination of two or more. Generally, the wetting agent is used in an amount of 0.1 to 5% by weight based on the total weight of the treatment liquid.

Examples of preservatives include 4-isothiazolin-3-one derivatives, benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, benztriazole 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, heterocyclic alkyl ammonium salts and the like can be preferably used. The heterocyclic alkyl ammonium salt is preferably one or more heterocyclic alkyl ammonium salts selected from the group consisting of alkyl-pyridinium salts, alkyl-quinolinium salts and alkyl-isoquinolinium salts, and alkyl having 8 to 18 carbon atoms. It is preferable to have a group.
The addition amount of the preservative is an amount that exerts stability against bacteria, molds, yeasts, etc., and varies depending on the type of bacteria, molds, yeasts, but is 0. The range of 01 to 4% by mass is preferable, and it is preferable to use two or more preservatives in combination so as to be effective against various molds and sterilization.

Examples of chelate compounds include ethylenediaminetetraacetic acid, potassium salt thereof, sodium salt thereof; diethylenetriaminepentaacetic acid, potassium salt thereof, sodium salt thereof; triethylenetetraminehexaacetic acid, potassium salt thereof, sodium salt thereof, and hydroxyethylethylenediaminetriacetic acid. Nitrilotriacetic acid, sodium salt; 1-hydroxyethane-1,1-diphosphonic acid, potassium salt, sodium salt; aminotri (methylenephosphonic acid), potassium salt, sodium salt And organic phosphonic acids and phosphonoalkanetricarboxylic acids. 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 are stably present in the treatment liquid composition and do not impair the printability. The addition amount is preferably 0.001 to 1.0% by mass with respect to the treatment liquid at the time of use.

  Examples of organic acids include citric acid, acetic acid, succinic acid, malonic acid, salicylic acid, caprylic acid, tartaric acid, malic acid, lactic acid, levulinic acid, p-toluenesulfonic acid, xylenesulfonic acid, phytic acid, and organic phosphonic acid. . The organic acid can also be used in the form of its alkali metal salt or ammonium salt. The content of the organic acid is preferably 0.01 to 0.5% by mass based on the total mass of the treatment liquid.

  Examples of the organic solvent that can be contained include aliphatic hydrocarbons (hexane, heptane, “Isopar E, H, G” (manufactured by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.), and aromatic hydrocarbons (toluene). , Xylene, etc.), halogenated hydrocarbons (methylene dichloride, ethylene dichloride, tricrene, monochlorobenzene, etc.) and polar solvents.

Polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol monoethyl ether , Propylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ether, methylphenyl carbinol, n-amyl alcohol, methyl amyl alcohol, etc.) , (Acetone, methyl ethyl ketone, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), esters (ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, methyl lactate, butyl lactate, ethylene glycol monobutyl acetate, propylene Glycol monomethyl ether acetate, diethylene glycol acetate, diethyl phthalate, butyl levulinate, etc.) and others (triethyl phosphate, tricresyl phosphate, N-phenylethanolamine, N-phenyldiethanolamine, etc.).

  If the organic solvent is insoluble in water, it can be used after being solubilized in water using a surfactant or the like. If the developer contains an organic solvent, safety, ignition, From the viewpoint of property, the concentration of the solvent is preferably less than 40% by mass.

  Examples of inorganic acids and inorganic salts include phosphoric acid, metaphosphoric acid, primary ammonium phosphate, secondary ammonium phosphate, primary sodium phosphate, secondary sodium phosphate, primary potassium phosphate, secondary potassium phosphate, Examples include sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, magnesium nitrate, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium sulfite, ammonium sulfite, sodium hydrogen sulfate, nickel sulfate and the like. The content of the inorganic salt is preferably 0.01 to 0.5% by mass based on the total mass of the treatment liquid.

The treatment liquid used in the present invention can be obtained by dissolving or dispersing each of the above components in water as necessary. The solid concentration of the treatment agent is preferably 2 to 25% by mass. A concentrated solution can be prepared and diluted with water at the time of use.
The pH of the treatment liquid used in the present invention is 2-8. From the viewpoint of developability and dispersibility of the image recording layer, it is advantageous to set the pH to a low value. However, it is more effective to set the pH value to a low value for the printability, especially the stain. Therefore, the preferred pH is 3-7, more preferably 3-6.

Examples of the method for bringing the treatment agent into contact with the lithographic printing plate precursor according to the invention include treatment by a machine such as immersion treatment and horizontal conveyance treatment.
The exposed lithographic printing plate precursor is preferably heated in a preheating section provided prior to development. The preheating part is preferably inserted and heated within 1 minute after exposure, and the heating temperature is generally 50 to 150 ° C, and particularly preferably 90 to 120 ° C.

  Next, development will be described. In the development processing, an apparatus with a simplified structure and a simplified process is used according to the development method of the present invention. Compared with a conventional alkali development system, it is less affected by carbon dioxide in the air, so that the sealing degree of air and liquid can be lowered. In addition, the desensitization treatment can be performed simultaneously with the development, and it is not always necessary to provide water washing and desensitization treatment steps after the conventional development, and a bath of 1 bath or at most 2 baths can be provided. Is enough. As a result, the cost of the apparatus can be reduced, and the apparatus can be installed in a much smaller space than the space required for the conventional apparatus. In general, since a rubbing member is indispensable in the development processing, a rubbing member such as a brush is installed in the developing bath for removing the non-image portion of the image recording layer.

The gum development processing in the present invention can be suitably carried out by an automatic processor equipped with a supply means such as a gum solution and a rubbing member. Examples of the automatic processor include an automatic processor described in Japanese Patent Application Laid-Open No. 2006-235227 that performs rubbing while conveying a lithographic printing plate precursor after image recording. Among these, an automatic processor using a rotating brush roll as the rubbing member is particularly preferable. Although there may be one rotating brush roll, it is preferable to have two or more rotating brush rolls.

The rotating brush roll that can be preferably used in the present invention can be appropriately selected in consideration of the difficulty of scratching the image area and the stiffness of the lithographic printing plate precursor support. As the rotating brush roll, a known one formed by planting a brush material on a plastic or metal roll can be used. For example, as described in Japanese Patent Application Laid-Open No. 58-159533, Japanese Patent Application Laid-Open No. 3-100554, or Japanese Utility Model Publication No. 62-167253, metal or plastic in which brush materials are implanted in rows. A brush roll can be used in which the groove mold material is radially wound around a plastic or metal roll as a core without a gap. The brush material includes plastic fibers (for example, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6.6 and nylon 6.10, polyacrylonitrile, poly (meth) acrylate, etc. Acrylic and polyolefin synthetic fibers such as polypropylene and polystyrene) can be used. For example, the fiber has a hair diameter of 20 to 400 μm and a hair length of 5 to 30 mm. Can be used.
Furthermore, the outer diameter of the rotating brush roll is preferably 30 to 200 mm, and the peripheral speed at the tip of the brush rubbing the plate surface is preferably 0.1 to 5 m / sec.

  The rotating direction of the rotating brush roll used in the present invention may be the same or opposite to the conveying direction of the planographic printing plate precursor of the present invention. Thus, when two or more rotating brush rolls are used, it is preferable that at least one rotating brush roll rotates in the same direction and at least one rotating brush roll rotates in the opposite direction. This further ensures the removal of the image recording layer in the non-image area. Furthermore, it is also effective to swing the rotating brush roll in the direction of the rotation axis of the brush roll.

  In the surfactant used in the present invention, the load on the rubbing member such as a brush is greatly reduced. In general, a developer in a low alkali to acidic region does not remove the non-image area unless it is developed under strong rubbing conditions to remove the image recording layer in the non-image area. However, the developer using the surfactant used in the present invention can be developed under the same level as the rubbing member used in normal alkali development and under the same rubbing conditions (rotation speed, brush pressure). It becomes.

  Of course, gum coaters and automatic developing machines known for PS plates and CTP plates can also be used in this system. When using a conventional automatic processor, for example, the processing liquid charged in the developing tank is pumped up and sprayed from the spray nozzle, and the printing plate is prepared by a submerged guide roll in the tank filled with the processing liquid. Any of a method of immersing and transporting and a so-called disposable processing method of supplying and processing a substantially unused processing solution for each plate as needed is applicable. In any system, those having a rubbing mechanism with a brush or a molton are more preferable. In addition, an apparatus in which a laser exposure unit and an automatic processor unit are integrated can be used.

[Lithographic printing plate precursor]
The lithographic printing plate precursor used in the plate making method of the present invention has a negative image recording layer which can be removed by printing ink, dampening water or both of them on the support and is cured by exposure. The negative type image recording layer contains (1) a polymerization initiator, (2) a polymerizable compound, and (3) a hydrophobic binder polymer as essential components from the viewpoint of easy development and good printing durability. A polymerizable image recording layer. Hereinafter, components and components of the lithographic printing plate precursor such as the image recording layer and the support will be described.

(Image recording layer)
<Polymerization initiator>
The polymerization initiator used in the present invention is a compound that initiates and accelerates polymerization of a compound having a polymerizable unsaturated group by generating radicals or acids by light or thermal energy. As such a polymerization initiator, a known radical generator or acid generator, a compound having a bond having a small bond dissociation energy, or the like can be appropriately selected and used.

  Examples of the compound generating the radical or acid include, for example, an organic halogen compound, a carbonyl compound, an organic peroxide, an azo compound, an azide compound, a metallocene compound, a hexaarylbiimidazole compound, an organic boron compound, a disulfone compound, and an oxime. Examples thereof include ester compounds and onium salt compounds.

  Specific examples of the organic halogen compound include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, JP 48-36281, JP 53-133428, JP 55-3070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62- 58241, JP-A 62-212401, JP-A 63-70243, JP-A 63-298339, P. The compound as described in Hutt, "Journal of Heterocyclic Chemistry" 1 (No. 3), (1970) is mentioned. Of these, oxazole compounds and S-triazine compounds substituted with a trihalomethyl group are preferred.

  More preferable examples include s-triazine derivatives in which at least one mono, di, or trihalogen-substituted methyl group is bonded to the s-triazine ring, and oxadiazole derivatives in which the oxadiazole ring is bonded. Specifically, for example, 2,4,6-tris (monochloromethyl) -s-triazine, 2,4,6-tris (dichloromethyl) -s-triazine, 2,4,6-tris (trichloromethyl) -S-triazine, 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2-n-propyl-4,6-bis (trichloromethyl) -s-triazine, 2- (α, α, β-trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [1- (P-methoxyphenyl) -2,4-butadienyl] -4,6-bis (trichloromethyl) -s-triazine, 2-styryl-4,6-bis (trichloromethyl) -s-triazine, 2- ( -Methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (pi-propyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p- Tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenylthio-4,6-bis ( Trichloromethyl) -s-triazine, 2-benzylthio-4,6-bis (trichloromethyl) -s-triazine, 2,4,6-tris (dibromomethyl) -s-triazine, 2,4,6-tris ( Tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl) -s-triazine, 2-methoxy-4,6-bis (tribromomethyl) Etc. -s- triazine and the following compounds.

Examples of the carbonyl compound include benzophenone, Michler ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone and other benzophenone derivatives, 2,2-dimethoxy- 2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl- (p-isopropylphenyl) ketone, 1- Hydroxy-1- (p-dodecylphenyl) ketone, 2-methyl- (4 ′-(methylthio) phenyl) -2-morpholino-1-propanone, 1,1,1-trichloromethyl- (p-butylphenyl) Acetophenone derivatives such as ketones, thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, p- Examples thereof include benzoic acid ester derivatives such as ethyl dimethylaminobenzoate and ethyl p-diethylaminobenzoate.

  As the azo compound, for example, an azo compound described in JP-A-8-108621 can be used.

  Examples of the organic peroxide include trimethylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (tert-butyl). Peroxy) cyclohexane, 2,2-bis (tert-butylperoxy) butane, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydro Peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, tert-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2, -Oxanoyl peroxide, succinic peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate , Dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert- Butyl peroxyoctanoate, tert-butyl peroxylaurate, tersyl carbonate, 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ − Tra- (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyl And di (t-hexylperoxydihydrogen diphthalate).

Examples of the metallocene compound include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705, Various titanocene compounds described in JP-A-5-83588, such as di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, Di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, di- -Cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-penta Fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4,6-trifluoropheny -1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4 , 5,6-pentafluorophen-1-yl, iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109, and the like.

  Examples of the hexaarylbiimidazole compound include the specification of JP-B-6-29285, U.S. Pat. Nos. 3,479,185, 4,311,783, and 4,622,286. And, specifically, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) )) 4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2 ′ -Bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (m-methoxyphenyl) biidazole, 2,2'-bis (o, o'-dichlorophenyl) -4,4', 5,5 '-Tetraphenylbiimidazole, 2, 2' Bis (o-nitrophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole 2,2′-bis (o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and the like.

  Examples of the organoboron compound include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, JP-A 2000-. No. 131837, Japanese Patent Application Laid-Open No. 2002-107916, Japanese Patent No. 2764769, Japanese Patent Application Laid-Open No. 2002-116539, and Kunz, Martin “Rad Tech '98. Proceeding April 19-22, 1998, Chicago”, etc. Organoborates described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561, and organic boron oxosulfonium complexes, JP-A-6-175554 No. 6, JP-A-6-17555 Organoboron iodonium complexes described in JP-A-9-188710, organoboron phosphonium complexes described in JP-A-9-188710, JP-A-6-348011, JP-A-7-128785, JP-A-7-140589, Examples thereof include organoboron transition metal coordination complexes such as Kaihei 7-306527 and JP-A-7-292014.

  Examples of the disulfone compound include compounds described in JP-A Nos. 61-166544 and 2003-328465.

  Examples of the oxime ester compound include JCS Perkin II (1979) 1653-1660), JCSPerkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, and JP-A 2000-66385. Compounds, compounds described in JP-A No. 2000-80068, specifically, compounds represented by the following structural formulas may be mentioned.

  Examples of the onium salt compound include S.I. I. Schlesinger, Photogr. Sci. Eng. 18, 387 (1974), T .; S. Diazonium salts described in Bal et al, Polymer, 21, 423 (1980), ammonium salts described in US Pat. No. 4,069,055, JP-A-4-365049, etc., US Pat. No. 4,069 , 055, 4,069,056, phosphonium salts described in European Patent Nos. 104,143, US Pat. Nos. 339,049, 410,201, JP -150848, JP-A-2-296514, iodonium salts, European Patent Nos. 370,693, 390,214, 233,567, 297,443, and 297 442, U.S. Pat. Nos. 4,933,377, 161,811, 410,201, 339,049, 4,760,013 No. 4,734,444, No. 2,833,827, German Patent No. 2,904,626, No. 3,604,580, No. 3,604,581 Or a sulfonium salt described in J. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), and onium salts such as arsonium salts.

The onium salts preferably used in the present invention are represented by the following general formulas (RI-I) to (RI-II).
An onium salt represented by I).

In the formula (RI-I), Ar ₁₁ represents an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include an alkyl group having 1 to 12 carbon atoms and a carbon number. 1-12 alkenyl group, C1-C12 alkynyl group, C1-C12 aryl group, C1-C12 alkoxy group, C1-C12 aryloxy group, halogen atom, C1-C1 12 alkylamino groups, C1-C12 dialkylamino groups, C1-C12 alkylamide groups or arylamide groups, carbonyl groups, carboxyl groups, cyano groups, sulfonyl groups, C1-C12 thioalkyl groups And a thioaryl group having 1 to 12 carbon atoms. Z ₁₁ ^- represents a monovalent anion, specifically a halogen ion, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, thiosulfonate ion, a sulfate ion Can be mentioned. Of these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion and sulfinate ion are preferable from the viewpoint of stability.

In the formula (RI-II), Ar ₂₁ and Ar ₂₂ each independently represent an aryl group having 20 or less carbon atoms which may have 1 to 6 substituents, and preferred substituents include 1 to 12 alkyl groups, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 1 to 12 carbon atoms, Halogen atom, C1-C12 alkylamino group, C1-C12 dialkylamino group, C1-C12 alkylamide group or arylamide group, carbonyl group, carboxyl group, cyano group, sulfonyl group, carbon Examples thereof include a thioalkyl group having 1 to 12 carbon atoms and a thioaryl group having 1 to 12 carbon atoms. Z ₂₁ ⁻ represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among them, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable in terms of stability and reactivity.

In the formula (RI-III), R ₃₁ , R ₃₂ and R ₃₃ are each independently an aryl group, alkyl group, alkenyl group or alkynyl having 20 or less carbon atoms, which may have 1 to 6 substituents. Represents a group. Among them, an aryl group is preferable from the viewpoint of reactivity and stability. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkynyl group having 1 to 12 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, Aryloxy group having 1 to 12 carbon atoms, halogen atom, alkylamino group having 1 to 12 carbon atoms, dialkylamino group having 1 to 12 carbon atoms, alkylamide group or arylamide group having 1 to 12 carbon atoms, carbonyl group, carboxyl Group, a cyano group, a sulfonyl group, a thioalkyl group having 1 to 12 carbon atoms, and a thioaryl group having 1 to 12 carbon atoms. Z ₃₁ ^- represents a monovalent anion. Specific examples include halogen ions, perchlorate ions, hexafluorophosphate ions, tetrafluoroborate ions, sulfonate ions, sulfinate ions, thiosulfonate ions, and sulfate ions. Among these, perchlorate ion, hexafluorophosphate ion, tetrafluoroborate ion, sulfonate ion, sulfinate ion, and carboxylate ion are preferable from the viewpoints of stability and reactivity. More preferred are the carboxylate ions described in JP-A No. 2001-343742, and particularly preferred are the carboxylate ions described in JP-A No. 2002-148790.

  The polymerization initiator is not limited to the above, but a triazine-based initiator, an organic halogen compound, an oxime ester compound, a diazonium salt, an iodonium salt, and a sulfonium salt are more preferable from the viewpoints of reactivity and stability.

  These polymerization initiators may be used alone or in combination of two or more. Moreover, these polymerization initiators may be added to the same layer as other components, or another layer may be provided and added thereto. These polymerization initiators are preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and particularly preferably 0.8 to 20% by mass with respect to the total solid content constituting the image recording layer. It can be added in proportions.

<Polymerizable compound>
The polymerizable compound that can be used in the present invention 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. It is. 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, i.e. dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of such monomers and copolymers thereof include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof. Preferably, 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, an amino group or a mercapto group with a monofunctional or polyfunctional isocyanate or epoxy, and a monofunctional or polyfunctional compound. 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, isocyanuric acid There are EO-modified triacrylate and the like.

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 -, and the like [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, for example, aliphatic alcohol esters described in JP-B-51-47334 and JP-A-57-196231, JP-A-59-5240, and JP-A-59-5241. And those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613. 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 (A) to a polyisocyanate compound having two or more isocyanate groups. Compound etc. are mentioned.

_{CH 2 = C (R 4)} COOCH 2 CH (R 5) OH (A)
(However, R ₄ and R ₅ represent H or CH _3. )

  Further, urethane acrylates such as those described in JP-A-51-37193, JP-B-2-32293, 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. Furthermore, 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, JP-A-1-105238, It is possible to obtain a photopolymerizable composition excellent in the photosensitive speed.

Other examples include reacting polyester acrylates, epoxy resins and (meth) acrylic acid as described in JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490. And polyfunctional acrylates and methacrylates such as epoxy acrylates. In addition, specific unsaturated compounds described in JP-B-46-43946, JP-B-1-40337, JP-B-1-40336, and vinylphosphonic acid-based compounds described in JP-A-2-25493 are also included. Can 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.

  Examples of the compound having a vinyl ether group used in the present invention include compounds described in JP-A-2002-029162. Specific examples include tetramethylene glycol divinyl ether, trimethylolpropane trivinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, 1,4-bis {2- (vinyloxy) ethyloxy} Benzene, 1,2-bis {2- (vinyloxy) ethyloxy} benzene, 1,3-bis {2- (vinyloxy) ethyloxy} benzene, 1,3,5-tris {2- (vinyloxy) ethyloxy} benzene, 4 , 4′-bis {2- (vinyloxy) ethyloxy} biphenyl, 4,4′-bis {2- (vinyloxy) ethyloxy} diphenyl ether, 4,4′-bis {2- (vinyloxy) ester Ruoxy} diphenylmethane, 1,4-bis {2- (vinyloxy) ethyloxy} naphthalene, 2,5-bis {2- (vinyloxy) ethyloxy} furan, 2,5-bis {2- (vinyloxy) ethyloxy} thiophene, , 5-bis {2- (vinyloxy) ethyloxy} imidazole, 2,2-bis [4- {2- (vinyloxy) ethyloxy} phenyl] propane {bis (vinyloxyethyl) ether of bisphenol A}, 2,2- Examples include, but are not limited to, bis {4- (vinyloxymethyloxy) phenyl} propane, 2,2-bis {4- (vinyloxy) phenyl} propane, and the like.

About these addition polymerizable compounds, the details of the method of use such as the structure, single use or combination, addition amount, etc. can be arbitrarily set according to the performance design of the final lithographic printing plate precursor. For example, it is selected from the following viewpoints.
From the viewpoint of sensitivity, a structure having a large 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 area, that is, the cured film, those having three or more functionalities are preferable. A method of adjusting both sensitivity and strength by using a compound) is also effective.
In addition, the selection and use method of the addition polymerization compound is also an important factor for compatibility and dispersibility with other components in the image recording layer (for example, water-insoluble polymer, 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 addition, a specific structure may be selected for the purpose of improving the adhesion of the substrate and the protective layer described later.

  The polymerizable compound is used in an amount of preferably 5 to 80% by mass, more preferably 25 to 75% by mass, based on the total solid content constituting the image recording layer. These may be used alone or in combination of two or more.

<Hydrophobic binder polymer>
As the hydrophobic binder polymer used in the image recording layer of the present invention, a water-insoluble polymer is preferably used. Furthermore, the hydrophobic binder polymer that can be used in the present invention preferably contains substantially no acid group such as a carboxyl group, a sulfone group, and a phosphoric acid group. The acid value of the binder polymer (the acid content per gram of polymer) Is expressed as a chemical equivalent number) is preferably 0.3 meq / g or less, and more preferably 0.1 meq / g or less.
That is, the hydrophobic binder polymer that can be used in the present invention is preferably insoluble in water and an aqueous solution of pH 10 or higher, and the solubility of the hydrophobic binder polymer in water and an aqueous solution of pH 10 or higher is 0.5% by mass or less. Preferably, it is 0.1% by mass or less. By using such a hydrophobic binder polymer, the film strength, water resistance and wall-thickness of the image recording layer are improved, and printing durability is improved.

As the hydrophobic binder polymer, as long as the performance of the lithographic printing plate of the present invention is not impaired, a conventionally known one can be used without limitation within the above range, and a linear organic polymer having a film property is preferable.
As an example of such a hydrophobic binder polymer, a polymer selected from acrylic resin, polyvinyl acetal resin, polyurethane resin, polyamide resin, epoxy resin, methacrylic resin, styrene resin, and polyester resin is preferable.

  Furthermore, the hydrophobic binder polymer can be provided with a crosslinking property in order to improve the film strength of the image area. In order to impart crosslinkability to the hydrophobic binder polymer, a crosslinkable functional group such as an ethylenically unsaturated bond may be introduced into the polymer. The crosslinkable functional group may be introduced by copolymerization. Examples of hydrophobic binder polymers having ethylenically unsaturated bonds in the molecule are polymers of esters or amides of acrylic acid or methacrylic acid, wherein the ester or amide residue (-COOR 'or -CONHR' R ') May include a polymer having an ethylenically unsaturated bond.

Examples of residues having an ethylenically unsaturated bond (above R ′) include — (CH ₂ ) _n CR ¹ ═CR ² R ³ , — (CH ₂ O) _n CH ₂ CR ¹ ═CR ² R ³ , _{- (CH 2 CH 2 O)} n CH 2 CR 1 = CR 2 R 3, - (CH 2) n NH-CO-O-CH 2 CR 1 = CR 2 R 3, - (CH 2) n -O- CO—CR ¹ ═CR ² R ³ and — (CH ₂ CH ₂ O) ₂ —X (wherein R ^{1 to} R ³ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group. Represents an alkoxy group or an aryloxy group, and R ¹ and R ² or R ³ may combine with each other to form a ring, n represents an integer of 1 to 10. X represents dicyclopentadi An enyl residue).
Specific examples of the ester _{residue, -CH 2 CH = CH 2,} ( described in JP Kokoku _{7-21633.) - CH 2 CH 2} O-CH 2 CH = CH 2, -CH 2 C _{(CH 3) = CH 2,} -CH 2 CH = CH-C 6 H 5, -CH 2 CH 2 OCOCH = CH-C 6 H 5, -CH 2 CH 2 -NHCOO-CH 2 CH = CH 2 and - CH ₂ CH ₂ O—X (wherein X represents a dicyclopentadienyl residue).
Specific examples of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (wherein Y represents a cyclohexene residue), —CH ₂ CH ₂ —OCO—CH═CH _2. Is mentioned.

  Hydrophobic binder polymers having crosslinkability include, for example, free radicals (polymerization initiation radicals or growth radicals in the polymerization process of a polymerizable compound) added to the crosslinkable functional group, and polymerization of polymerizable compounds directly between polymers. Addition polymerization through a chain forms a cross-link between polymer molecules and cures. Alternatively, atoms in the polymer (eg, hydrogen atoms on carbon atoms adjacent to the functional bridging group) are abstracted by free radicals to form polymer radicals that are bonded to each other so that crosslinking between the polymer molecules occurs. Forms and cures.

  The content of the crosslinkable group in the hydrophobic binder polymer (content of unsaturated double bond capable of radical polymerization by iodine titration) is preferably 0.1 to 10.0 mmol, more preferably 1 g per 1 g of the hydrophobic binder polymer. Is 1.0 to 7.0 mmol, most preferably 2.0 to 5.5 mmol.

  It is also preferable that the binder polymer is hydrophilic from the viewpoint of improving developability with respect to an aqueous solution, and it is important that the binder polymer has good compatibility with the polymerizable compound contained in the image recording layer from the viewpoint of improving printing durability. That is, it is preferable to be lipophilic. From such a viewpoint, in the present invention, it is also effective to copolymerize a hydrophilic group and a lipophilic group in a hydrophobic binder polymer in order to improve developability and printing durability. Examples of the hydrophilic group include a hydroxy group, a carboxylate group, a hydroxyethyl group, an ethyleneoxy group, a hydroxypropyl group, a polyoxyethyl group, a polyoxypropyl group, an amino group, an aminoethyl group, an aminopropyl group, and an ammonium group. And those having a hydrophilic group such as an amide group or a carboxymethyl group.

The hydrophobic binder polymer preferably has a mass average molecular weight of 5,000 or more, more preferably 10,000 to 300,000, and a number average molecular weight of 1,000 or more, preferably 2000 to 250,000. Is more preferable. The polydispersity (mass average molecular weight / number average molecular weight) is preferably 1.1 to 10.
The hydrophobic binder polymer may be any of a random polymer, a block polymer, a graft polymer, and the like, but is preferably a random polymer.

The hydrophobic binder polymer may be used alone or in combination of two or more.
The content of the hydrophobic binder polymer is 5 to 90% by mass, preferably 10 to 70% by mass, and more preferably 10 to 60% by mass with respect to the total solid content of the image recording layer. . Within this range, good image area strength and image formability can be obtained.

<Infrared absorber>
For the image recording layer of the lithographic printing plate precursor that performs imagewise exposure using a light source that emits infrared rays, an infrared absorber can be used in combination with the polymerization initiator. The infrared absorber has a function of converting absorbed infrared rays into heat, and the polymerization initiator is thermally decomposed by the heat generated at this time to generate radicals. The infrared absorber used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 to 1200 nm.

  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 Is mentioned.

  Preferred dyes include, for example, cyanine dyes described in JP-A-58-125246, JP-A-59-84356, JP-A-60-78787, JP-A-58-173696, The methine dyes described in Japanese Laid-Open Patent Publication Nos. 58-181690 and 58-194595, JP-A 58-112793, JP-A 58-224793, JP-A 59-48187, Naphthoquinone dyes described in Japanese Laid-Open Patent Publication Nos. 59-73996, 60-52940 and 60-63744, and squarylium dyes described in Japanese Laid-Open Patent Publication No. 58-112792. And cyanine dyes described in British Patent 434,875.

In addition, a near infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also suitable. ) Pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59- No. 41363, 59-84248, 59-84249, 59-146063, 59-146061, pyranyl compounds described in JP-A-59-216146, cyanine dyes described in JP-A-59-216146, Patented in US Pat. No. 4,283,475, such as pentamethine thiopyrylium salt, and Japanese Patent Publication Nos. 5-13514 and 5-19702 Pyrylium compounds are also preferably used. Another example of a preferable dye is a near-infrared absorbing dye described in US Pat. No. 4,756,993 as formulas (I) and (II).

  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 one particularly preferred example is a cyanine dye represented by the following general formula (II).

In general formula (II), 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. Xa ^- the Za described later ^- is defined as for, 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.

R ¹ and R ² each independently represents a hydrocarbon group having 1 to 12 carbon atoms. From the storage stability of the recording layer coating solution, R ¹ and R ² are preferably hydrocarbon groups having 2 or more carbon atoms, and R ¹ and R ² are bonded to each other to form a 5-membered ring or It is particularly preferable that 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. Moreover, as a preferable substituent, a C12 or less hydrocarbon group, a halogen atom, and a C12 or less alkoxy group are mentioned. 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. Za ⁻ represents a counter anion. However, Za ⁻ is not necessary when the cyanine dye represented by formula (II) has an anionic substituent in its structure and neutralization of charge is not necessary. Preferred Za ⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, particularly preferably a perchlorate ion, a hexagonal salt, in view of the storage stability of the recording layer coating solution. Fluorophosphate ions and aryl sulfonate ions.

Specific examples of the cyanine dye represented by formula (II) that can be suitably used in the present invention include those described in paragraph numbers [0017] to [0019] of JP-A No. 2001-133969. be able to.
Further, other particularly preferable examples include specific indolenine cyanine dyes described in JP-A-2002-278057.

  Examples of pigments used as infrared absorbers in the present invention include commercially available pigments and Color Index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technical Association, published in 1977), “Latest Pigment Applied Technology”. (CMC Publishing, published in 1986) and “Printing Ink Technology”, published by CMC Publishing, published in 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 , Quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like. 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 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 Application of Metal Soap” (Shobobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). Yes.

  The particle diameter of the pigment is preferably in the range of 0.01 to 10 μm, more preferably in the range of 0.05 to 1 μm, and particularly preferably in the range of 0.1 to 1 μm. Within this range, good stability of the pigment dispersion in the image recording layer coating solution and good uniformity of the image recording layer can be obtained.

As a method for dispersing the pigment, a known dispersion technique used for ink production or toner production 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).

  The addition of these infrared absorbers to the image recording layer is preferably made the minimum necessary amount in order to suppress side effects that inhibit the polymerization reaction.

  These infrared absorbers are preferably 0.001 to 50% by mass, more preferably 0.005 to 30% by mass, and particularly preferably 0.01 to 10% by mass with respect to the total solid content of the image recording layer. Can be added. Within this range, high sensitivity can be obtained without adversely affecting the uniformity and film strength of the image recording layer.

<Sensitizer>
It is also possible to increase radical generation efficiency by using a sensitizer in combination with the above polymerization initiator in the image recording layer of a lithographic printing plate precursor that performs imagewise exposure using a light source that emits light of 250 to 420 nm. it can.

  Specific examples of the sensitizer include benzoin, benzoin methyl ether, benzoin ethyl ether, 9-fluorenone, 2-chloro-9-fluorenone, 2-methyl-9-fluorenone, 9-anthrone, and 2-bromo-9-anthrone. 2-ethyl-9-anthrone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthraquinone, 2,6-dichloro-9,10-anthraquinone, xanthone 2-methylxanthone, 2-methoxyxanthone, thioxanthone, benzyl, dibenzalacetone, p- (dimethylamino) phenyl styryl ketone, p- (dimethylamino) phenyl p-methylstyryl ketone, benzophenone, p- (dimethylamino) ) Benzophenone (or Michlerketo) ), P- (diethylamino) benzophenone, and the like benzanthrone.

  Furthermore, preferred sensitizers in the present invention include compounds represented by the general formula (III) described in Japanese Patent Publication No. 51-48516.

In the formula, R ¹⁴ is an alkyl group (for example, methyl group, ethyl group, propyl group, etc.) or a substituted alkyl group (for example, 2-hydroxyethyl group, 2-methoxyethyl group, carboxymethyl group, 2-carboxyethyl group) Etc.). R ¹⁵ represents an alkyl group (eg, methyl group, ethyl group, etc.) or an aryl group (eg, phenyl group, p-hydroxyphenyl group, naphthyl group, thienyl group, etc.).

Z ² is a group of nonmetallic atoms necessary for forming a heterocyclic nucleus containing nitrogen, which is usually used in cyanine dyes, such as benzothiazoles (benzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole, etc.), naphtho Thiazoles (α-naphthothiazole, β-naphthothiazole, etc.), benzoselenazoles (benzoselenazole, 5-chlorobenzoselenazole, 6-methoxybenzoselenazole, etc.), naphthoselenazoles (α-
Naphthoselenazole, β-naphthoselenazole, etc.), benzoxazoles (benzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, etc.), naphthoxazoles (α-naphthoxazole, β-naphthoxazole, etc.) .

Specific examples of the compound represented by the general formula (III) are those having a chemical structure combining these Z ² , R ¹⁴ and R ¹⁵ , and many exist as known substances. Therefore, it can be used by appropriately selecting from these known ones. Furthermore, preferable sensitizers in the present invention include merocyanine dyes described in JP-B-5-47095 and ketocoumarin compounds represented by the following general formula (IV).

Here, R ¹⁶ represents an alkyl group such as a methyl group or an ethyl group.

  These sensitizers are preferably from 0.1 to 50 mass%, more preferably from 0.5 to 30 mass%, particularly preferably from 0.8 to 20 mass%, based on the total solid content constituting the image recording layer. Can be added.

<Microcapsule>
In the present invention, as a method for incorporating the above-mentioned constituent components of the image recording layer and other constituent components described later into the image recording layer, for example, those described in JP-A Nos. 2001-277740 and 2001-277742 are disclosed. As described above, a part of the constituent components can be encapsulated in microcapsules and added to the image recording layer. In that case, each component can be contained in any ratio in and out of the microcapsule.

As a method for microencapsulating the constituent components of the image recording layer, known methods can be applied. For example, as a method for producing microcapsules, a method using coacervation found in U.S. Pat. Nos. 2,800,547 and 2,800,498, U.S. Pat. No. 3,287,154, JP-B-38-19574, 42-446 by the interfacial polymerization method, US Pat. No. 3,418,250, US Pat. No. 3,660,304 by polymer precipitation method, US Pat. No. 3,796,669, isocyanate polyol A method using a wall material, a method using an isocyanate wall material found in US Pat. No. 3,914,511, and a urea-formaldehyde system found in US Pat. Nos. 4,001,140, 4,087,376 and 4,089,802. Or urea formaldehyde-resorcino A method using a wall forming material, a method using a wall material such as melamine-formaldehyde resin and hydroxycellulose, as shown in US Pat. No. 4,025,445, and Japanese Patent Publication Nos. 36-9163 and 51-9079. In situ method by monomer polymerization, British Patent No. 930422, US Pat. No. 3,111,407 Spray drying method, British Patent Nos. 952807, 96707
Although there is an electrolytic dispersion cooling method or the like found in each specification of No. 4, it is not limited thereto.

  A preferable microcapsule wall used in the present invention has a three-dimensional cross-linking and has a property of swelling with a solvent. From such a viewpoint, the wall material of the microcapsule is preferably polyurea, polyurethane, polyester, polycarbonate, polyamide, and a mixture thereof, and particularly preferably polyurea and polyurethane. Moreover, you may introduce | transduce into the microcapsule wall the compound which has crosslinkable functional groups, such as an ethylenically unsaturated bond which can be introduce | transduced into said water-insoluble polymer.

  The average particle size of the microcapsules is preferably 0.01 to 3.0 μm. 0.05-2.0 micrometers is further more preferable, and 0.10-1.0 micrometer is especially preferable. Within this range, good resolution and stability over time can be obtained.

[Other components of image recording layer]
The image recording layer of the present invention can further contain various additives as required. These will be described below.

<Hydrophilic polymer>
The image recording layer in the lithographic printing plate precursor according to the invention may contain a hydrophilic polymer in order to improve developability and microcapsule dispersion stability.
Examples of the hydrophilic polymer include hydroxy group, carboxyl group, carboxylate group, hydroxyethyl group, polyoxyethyl group, hydroxypropyl group, polyoxypropyl group, amino group, aminoethyl group, aminopropyl group, ammonium group, Preferred examples include those having a hydrophilic group such as an amide group, carboxymethyl group, sulfonic acid group, and phosphoric acid group.

  Specific examples include gum arabic, casein, gelatin, starch derivatives, carboxymethylcellulose and its sodium salt, cellulose acetate, sodium alginate, vinyl acetate-maleic acid copolymers, styrene-maleic acid copolymers, polyacrylic acids and their salts, Polymethacrylic acids and their salts, homopolymers and copolymers of hydroxyethyl methacrylate, homopolymers and copolymers of hydroxyethyl acrylate, homopolymers and copolymers of hydroxypropyl methacrylate, homopolymers and copolymers of hydroxypropyl acrylate, homopolymers of hydroxybutyl methacrylate Polymers and copolymers, homopolymers and copolymers of hydroxybutyl acrylate Polyethylene glycols, hydroxypropylene polymers, polyvinyl alcohols, hydrolyzed polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl pyrrolidone, acrylamide homopolymers and copolymers having a hydrolysis degree of 60 mol% or more, preferably 80 mol% or more , Homopolymers and polymers of methacrylamide, homopolymers and copolymers of N-methylolacrylamide, polyvinylpyrrolidone, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, etc. Is mentioned.

The hydrophilic polymer preferably has a mass average molecular weight of 5000 or more, more preferably 10,000 to 300,000. The hydrophilic polymer may be any of a random polymer, a block polymer, a graft polymer, and the like.
The content of the hydrophilic polymer in the image recording layer is preferably 20% by mass or less, more preferably 10% by mass or less, based on the total solid content of the image recording layer.

<Surfactant>
In the present invention, it is preferable to use a surfactant in the image recording layer in order to promote developability and improve the coated surface state. Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and fluorosurfactants. Surfactant may be used independently and may be used in combination of 2 or more type.

  The nonionic surfactant used for this invention is not specifically limited, A conventionally well-known thing can be used. For example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid partial esters, sorbitan fatty acid partial esters, pentaerythritol Fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters, Polyoxyethylenated castor oil, polyoxyethylene glycerin fatty acid partial esters, fatty acid diethanolamides, N N- bis-2-hydroxyalkylamines, polyoxyethylene alkylamines, triethanolamine fatty acid ester, trialkylamine oxide, polyethylene glycol, copolymers of polyethylene glycol and polypropylene glycol.

  The anionic surfactant used in the present invention is not particularly limited, and conventionally known anionic surfactants can be used. For example, fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, dialkyl sulfosuccinate esters, linear alkyl benzene sulfonates, branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkyl phenoxy poly Oxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acid monoamide disodium salt, petroleum sulfonates, sulfated beef oil, fatty acid alkyl esters Sulfates, alkyl sulfates, polyoxyethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alcohol Ruphenyl ether sulfates, polyoxyethylene styryl phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyl phenyl ether phosphates, styrene / maleic anhydride Examples thereof include partial saponification products of polymers, partial saponification products of olefin / maleic anhydride copolymers, and naphthalene sulfonate formalin condensates.

The cationic surfactant used in the present invention is not particularly limited, and conventionally known cationic surfactants can be used. Examples thereof include alkylamine salts, quaternary ammonium salts, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
The amphoteric surfactant used in the present invention is not particularly limited, and conventionally known amphoteric surfactants can be used. Examples thereof include carboxybetaines, aminocarboxylic acids, sulfobetaines, aminosulfuric esters, and imidazolines.

  Of the above surfactants, the term “polyoxyethylene” can be read as “polyoxyalkylene” such as polyoxymethylene, polyoxypropylene, polyoxybutylene, etc. These surfactants can also be used.

More preferable surfactants include fluorine-based surfactants containing a perfluoroalkyl group in the molecule. Examples of such fluorosurfactants include anionic types such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl phosphates; amphoteric types such as perfluoroalkyl betaines; Cation type such as trimethylammonium salt; perfluoroalkylamine oxide, perfluoroalkylethylene oxide adduct, oligomer containing perfluoroalkyl group and hydrophilic group, oligomer containing perfluoroalkyl group and lipophilic group, perfluoroalkyl Nonionic types such as an oligomer containing a group, a hydrophilic group and a lipophilic group, and a urethane containing a perfluoroalkyl group and a lipophilic group. Also preferred are the fluorosurfactants described in JP-A-62-170950, JP-A-62-226143 and JP-A-60-168144.

Surfactant can be used individually or in combination of 2 or more types.
The content of the surfactant is preferably 0.001 to 10% by mass, and more preferably 0.01 to 7% by mass, based on the total solid content of the image recording layer.

<Colorant>
In the present invention, a dye having a large absorption in the visible light region can be used as an image colorant. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (orientated chemistry) Kogyo Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), etc., and JP-A-62-2 And dyes described in Japanese Patent No. 293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, titanium oxide, etc. can be suitably used.

  These colorants are preferably added since it is easy to distinguish an image area from a non-image area after image formation. The amount added is preferably 0.01 to 10% by mass with respect to the total solid content of the image recording material.

<Bakeout agent>
In the image recording layer of the present invention, a compound that changes color by an acid or a radical can be added to produce a printout image. As such a compound, for example, various dyes such as diphenylmethane, triphenylmethane, thiazine, oxazine, xanthene, anthraquinone, iminoquinone, azo, and azomethine are effectively used.

Specific examples include brilliant green, ethyl violet, methyl green, crystal violet, basic fuchsin, methyl violet 2B, quinaldine red, rose bengal, methanyl yellow, thymol sulfophthalein, xylenol blue, methyl orange, paramethyl red, Congo Fred, Benzopurpurin 4B, α-Naphthyl Red, Nile Blue 2B, Nile Blue A, Methyl Violet, Malachide Green, Parafuchsin, Victoria Pure Blue BOH [manufactured by Hodogaya Chemical Co., Ltd.], Oil Blue # 603 [Orient Chemical Kogyo Co., Ltd.], Oil Pink # 312 [Orient Chemical Co., Ltd.], Oil Red 5B [Orient Chemical Co., Ltd.], Oil Scarlet # 308 [Orient Gaku Kogyo Co., Ltd.], Oil Red OG [Orient Chemical Co., Ltd.], Oil Red RR [Orient Chemical Co., Ltd.], Oil Green # 502 [Orient Chemical Co., Ltd.], Spiron Red BEH Special [made by Hodogaya Chemical Co., Ltd.], m-cresol purple, cresol red, rhodamine B, rhodamine 6G, sulforhodamine B, auramine, 4-p-diethylaminophenyliminonaphthoquinone, 2-carboxyanilino-4-p- Diethylaminophenyliminonaphthoquinone, 2-carboxystearylamino-4-pN, N-bis (hydroxyethyl) amino-phenyliminonaphthoquinone, 1-phenyl-3-methyl-4-p-diethylaminophenylimino-5-pyrazolone, 1-β-naphthyl-4- - dyes and p of diethylamino phenyl imino-5-pyrazolone, p ', p "- hexamethyl triamnotriphenylmethane (leuco crystal violet), and a leuco dye such as Pergascript Blue SRB (manufactured by Ciba-Geigy).

  In addition to the above, a leuco dye known as a material for thermal paper or pressure-sensitive paper is also suitable. Specific examples include crystal violet lactone, malachite green lactone, benzoylleucomethylene blue, 2- (N-phenyl-N-methylamino) -6- (Np-tolyl-N-ethyl) amino-fluorane, 2-anilino. -3-methyl-6- (N-ethyl-p-toluidino) fluorane, 3,6-dimethoxyfluorane, 3- (N, N-diethylamino) -5-methyl-7- (N, N-dibenzylamino) ) -Fluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3- (N, N-diethylamino) -6-methyl-7-anilinofluorane, 3 -(N, N-diethylamino) -6-methyl-7-xylidinofluorane, 3- (N, N-diethylamino) -6-methyl-7-chloro Fluorane, 3- (N, N-diethylamino) -6-methoxy-7-aminofluorane, 3- (N, N-diethylamino) -7- (4-chloroanilino) fluorane, 3- (N, N-diethylamino) -7-chlorofluorane, 3- (N, N-diethylamino) -7-benzylaminofluorane, 3- (N, N-diethylamino) -7,8-benzofluorane, 3- (N, N-dibutyl) Amino) -6-methyl-7-anilinofluorane, 3- (N, N-dibutylamino) -6-methyl-7-xylidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane 3-pyrrolidino-6-methyl-7-anilinofluorane, 3,3-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3-bis (1-n-butyl- -Methylindol-3-yl) phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl- 2-methylindol-3-yl) -4-zaphthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, and the like.

  A suitable addition amount of the dye that changes color by an acid or a radical is 0.01 to 15% by mass with respect to the solid content of the image recording layer.

<Polymerization inhibitor>
In the image recording layer of the present invention, it is preferable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the radical polymerizable compound during the production or storage of the image recording layer.
Examples of the thermal polymerization inhibitor 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-nitroso-N-phenylhydroxylamine aluminum salt are preferred.
The addition amount of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the image recording layer.

<Higher fatty acid derivatives, etc.>
In order to prevent polymerization inhibition by oxygen, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to the image recording layer of the present invention, and the surface of the image recording layer is dried during the coating process. It may be unevenly distributed. The amount of the higher fatty acid derivative added is preferably about 0.1 to about 10% by mass with respect to the total solid content of the image recording layer.

<Plasticizer>
The image recording layer of the present invention may contain a plasticizer. Examples of the plasticizer include phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, dioctyl phthalate, octyl capryl phthalate, dicyclohexyl phthalate, ditridecyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, diallyl phthalate; Glycol esters such as glycol phthalate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, triethylene glycol dicaprylate; Phosphate esters such as tricresyl phosphate and triphenyl phosphate Diisobutyl adipate, dioctyl adipate, dimethyl sebacate, dibutyl sebacate, dioct Ruazereto, aliphatic dibasic acid esters such as dibutyl maleate; polyglycidyl methacrylate, triethyl citrate, glycerin triacetyl ester, butyl laurate in. The plasticizer content is preferably about 30% by mass or less based on the total solid content of the image recording layer.

<Inorganic fine particles>
The image recording layer of the present invention may contain inorganic fine particles in order to improve the strength of the cured film in the image area. As the inorganic fine particles, for example, silica, alumina, magnesium oxide, titanium oxide, magnesium carbonate, calcium alginate, or a mixture thereof is preferably exemplified. Even if they are not photothermally convertible, they can be used for strengthening the film, enhancing interfacial adhesion by surface roughening, and the like. The inorganic fine particles preferably have an average particle size of 5 nm to 10 μm, and more preferably 0.5 to 3 μm. Within the above range, it is possible to form a non-image portion excellent in hydrophilicity that is stably dispersed in the image recording layer, sufficiently retains the film strength of the image recording layer, and hardly causes stains during printing. .
The inorganic fine particles as described above can be easily obtained as a commercial product such as a colloidal silica dispersion.
The content of the inorganic fine particles is preferably 20% by mass or less, and more preferably 10% by mass or less, based on the total solid content of the image recording layer.

<Low molecular hydrophilic compound>
The image recording layer of the present invention can contain a hydrophilic low molecular weight compound in order to improve developability. Examples of hydrophilic low molecular weight compounds include water-soluble organic compounds such as glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and tripropylene glycol, and ether or ester derivatives thereof, glycerin, Polyhydroxys such as pentaerythritol, organic amines such as triethanolamine and diethanolamine monoethanolamine and salts thereof, organic sulfonic acids such as toluenesulfonic acid and benzenesulfonic acid and salts thereof, organic phosphonic acids such as phenylphosphonic acid and the like Examples thereof include organic carboxylic acids such as salts thereof, tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, gluconic acid and amino acids, and salts thereof.

<Formation of image recording layer>
The image recording layer of the present invention is formed by preparing or applying a coating solution by dispersing or dissolving the necessary components described above in a solvent. Solvents used here include ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyllactone, toluene, water, and the like. However, the present invention is not limited to this. These solvents are used alone or in combination. The solid content concentration of the coating solution is preferably 1 to 50% by mass.
The image recording layer of the present invention can be formed by preparing a plurality of coating solutions in which the same or different components are dispersed or dissolved in the same or different solvents, and repeatedly applying and drying a plurality of times.

The coating, the coating amount of the image recording layer on the support obtained after drying (solid content) may be varied according to the intended purpose, generally 0.3 to 3.0 g / m ² is preferred. Within this range, good sensitivity and good film properties of the image recording layer can be obtained.
Various methods can be used as a coating method. Examples thereof include bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, and roll coating.

(Support)
The support used in the lithographic printing plate precursor according to the invention is not particularly limited as long as it is a dimensionally stable plate-like hydrophilic support. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. Preferable supports include a polyester film and an aluminum plate. Among these, an aluminum plate that has good dimensional stability and is relatively inexpensive is preferable.

  The aluminum plate is a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a trace amount of different elements, or a plastic laminated on a thin film of aluminum or an aluminum alloy. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is preferably 10% by mass or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to manufacture in terms of refining technology, and therefore may contain a slightly different element. The composition of the aluminum plate is not specified, and a publicly known material can be used as appropriate.

  The thickness of the support is preferably from 0.1 to 0.6 mm, more preferably from 0.15 to 0.4 mm, and even more preferably from 0.2 to 0.3 mm.

  Prior to using the aluminum plate, it is preferable to perform a surface treatment such as roughening treatment or anodizing treatment. By the surface treatment, it is easy to improve hydrophilicity and secure adhesion between the image recording layer and the support. Prior to the roughening treatment of the aluminum plate, a degreasing treatment with a surfactant, an organic solvent, an alkaline aqueous solution or the like for removing rolling oil on the surface is performed as desired.

The surface roughening treatment of the aluminum plate is performed by various methods. For example, mechanical surface roughening treatment, electrochemical surface roughening treatment (surface roughening treatment for dissolving the surface electrochemically), chemical treatment, etc. Surface roughening treatment (roughening treatment that chemically selectively dissolves the surface).
As a method for the mechanical surface roughening treatment, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used.
Examples of the electrochemical surface roughening treatment include a method in which an alternating current or a direct current is used in an electrolytic solution containing an acid such as hydrochloric acid or nitric acid. Another example is a method using a mixed acid as described in JP-A-54-63902.

  The surface-roughened aluminum plate is subjected to an alkali etching treatment using an aqueous solution of potassium hydroxide, sodium hydroxide or the like, if necessary, further neutralized, and if desired, wear resistant. In order to increase the anodic oxidation treatment.

As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, hydrochloric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte.
The conditions for anodizing treatment vary depending on the electrolyte used and cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / day. d m ² , voltage 1 to 100 V, and electrolysis time 10 seconds to 5 minutes are preferable. The amount of the anodized film formed is preferably from 1.0 to 5.0 g / m ^2, and more preferably 1.5 to 4.0 g / m ^2. Within this range, good printing durability and good scratch resistance of the non-image area of the lithographic printing plate can be obtained.

  As the support used in the present invention, the substrate having the above-mentioned surface treatment and having an anodized film may be used as it is, but for further improvement in adhesion to the upper layer, hydrophilicity, resistance to contamination, heat insulation and the like. If necessary, it contains a micropore enlargement treatment, a micropore sealing treatment, and a hydrophilic compound described in Japanese Patent Application Laid-Open Nos. 2001-253181 and 2001-322365. A surface hydrophilization treatment immersed in an aqueous solution can be selected as appropriate. Of course, these enlargement processing and sealing processing are not limited to those described above, and any conventionally known method can be performed.

Sealing treatment includes vapor sealing, single treatment with zirconic fluoride, treatment with an aqueous solution containing an inorganic fluorine compound such as treatment with sodium fluoride, vapor sealing with addition of lithium chloride, sealing with hot water. Hole processing is also possible.
Of these, sealing treatment with an aqueous solution containing an inorganic fluorine compound, sealing treatment with water vapor, and sealing treatment with hot water are preferable.

In the present invention, when developing with a developer of pH 2-8, particularly when developing with a developer of pH 2-8 having a compound represented by the structure of the general formula (1), It is preferable to perform the hydrophilization treatment by immersing in an aqueous solution containing a hydrophilic compound. In particular, it is preferable to perform surface treatment with alkali metal silicate treatment and / or organic phosphonic acid as shown below.
The hydrophilization treatment is described in the specifications of US Pat. Nos. 2,714,066, 3,181,461, 3,280,734, and 3,902,734. Such an alkali metal silicate method is preferably used. In this method, the support is immersed in an aqueous solution such as sodium silicate or electrolytically treated. In addition, the treatment with potassium zirconate fluoride described in JP-B 36-22063, U.S. Pat. Nos. 3,276,868, 4,153,461 and 4,689, A method of treating with polyvinyl phosphonic acid which is an organic phosphonic acid as described in the specification of No. 272 is preferably used.
In the treatment with organic phosphonic acid which is a preferred embodiment, in addition to treatment with polyvinylphosphonic acid, surface treatment with polyvinylmethylphosphonic acid and phosphoric acid ester of polyvinyl alcohol is highly effective, but treatment with polyvinylphosphonic acid is particularly effective. . When this treatment is used, the residual color at the time of development is not easily lost, and printing stains are very good.

When using a support with insufficient surface hydrophilicity such as a polyester film as the support of the present invention, it is desirable to apply a hydrophilic layer to make the surface hydrophilic. As the hydrophilic layer, at least one element selected from beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony, and a transition metal described in JP-A-2001-199175 A hydrophilic layer obtained by coating a coating solution containing a colloid of oxide or hydroxide, or an organic hydrophilic polymer obtained by crosslinking or pseudo-crosslinking an organic hydrophilic polymer described in JP-A No. 2002-79772 A hydrophilic layer having a hydrophilic matrix, a hydrophilic layer having an inorganic hydrophilic matrix obtained by sol-gel conversion comprising hydrolysis, condensation reaction of polyalkoxysilane, titanate, zirconate or aluminate, or a metal oxide A hydrophilic layer made of an inorganic thin film having a surface is preferred. Arbitrariness. Among these, a hydrophilic layer formed by applying a coating solution containing a silicon oxide or hydroxide colloid is preferable.

  Moreover, when using a polyester film etc. as a support body of this invention, it is preferable to provide an antistatic layer in the hydrophilic layer side of a support body, the opposite side, or both sides. In the case where the antistatic layer is provided between the support and the hydrophilic layer, it also contributes to improving the adhesion with the hydrophilic layer. As the antistatic layer, a polymer layer in which metal oxide fine particles or a matting agent are dispersed as described in JP-A-2002-79772 can be used.

The support preferably has a center line average roughness of 0.10 to 1.2 μm. Within this range, good adhesion with the image recording layer, good printing durability and good stain resistance can be obtained.
The color density of the support is preferably 0.15 to 0.65 as the reflection density value. Within this range, good image formability by preventing halation during image exposure and good plate inspection after development can be obtained.

(Undercoat layer)
In the lithographic printing plate precursor according to the invention, it is preferable to provide an undercoat layer of a compound containing a polymerizable group on a support. When an undercoat layer is used, the image recording layer is provided on the undercoat layer. The undercoat layer enhances the adhesion between the support and the image recording layer in the exposed area, and in the unexposed area, the image recording layer is easily peeled off from the support, so that the developability is improved. .
As the undercoat layer, specifically, a silane coupling agent having an addition-polymerizable ethylenic double bond reactive group described in JP-A-10-282679, JP-A-2-304441. The phosphorus compound etc. which have the ethylenic double bond reactive group of description are mentioned suitably. Particularly preferable compounds include compounds having a polymerizable group such as a methacryl group or an allyl group and a support adsorbing group such as a sulfonic acid group, a phosphoric acid group, or a phosphoric acid ester. A compound having a hydrophilicity-imparting group such as an ethylene oxide group in addition to the polymerizable group and the support-adsorbing group can also be exemplified as a suitable compound.
The coating amount (solid content) of the undercoat layer is preferably from 0.1-100 mg / m ^2, and more preferably 1 to 30 mg / m ^2.

(Protective layer)
In the lithographic printing plate precursor according to the present invention, a water-soluble protective layer may be provided on the image recording layer in order to prevent the occurrence of scratches in the image recording layer, to block oxygen, and to prevent ablation during high-illuminance laser exposure. it can.
In the present invention, exposure is usually carried out in the atmosphere, but the protective layer is an image of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that inhibit radical polymerization reactions caused by exposure in the image recording layer. This prevents the recording layer from being mixed, and prevents the image formation reaction from being hindered by exposure in the air. Therefore, the properties desired for the protective layer are low permeability of low-molecular compounds such as oxygen, furthermore, good transparency of light used for exposure, excellent adhesion to the image recording layer, and It is preferable that it can be easily removed with an aqueous solution of simple development after exposure. Various studies have been made on the protective layer having such characteristics, and are described in detail, for example, in US Pat. No. 3,458,311 and JP-B-55-49729.

Examples of the material used for the protective layer include water-soluble polymer compounds that are relatively excellent in crystallinity. Specific examples include water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid. Among these, when polyvinyl alcohol (PVA) is used as a main component, the best results are obtained for basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol may be partially substituted with an ester, ether or acetal as long as it contains an unsubstituted vinyl alcohol unit for providing the oxygen barrier property and water solubility necessary for the protective layer, and a part of the other You may have a copolymerization component.
Specific examples of the polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a degree of polymerization of 300 to 2400. Specifically, for example, PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA manufactured by Kuraray Co., Ltd. -HC, PVA-203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405 , PVA-420, PVA-613, and L-8.
As the acid-modified polyvinyl alcohol, one obtained by modifying a part of the hydroxyl group of polyvinyl alcohol with a sulfonic acid group or a carboxylic acid group is preferable. Among these, as sulfonic acid-modified polyvinyl alcohol, for example, Nippon Gosei Chemical Industry Co., Ltd .: Goseiran L-3266, L-0302, Kuraray Co., Ltd .: Kuraray SK Polymer SK-5102, S-2217, etc. Further, as the carboxylic acid-modified polyvinyl alcohol, for example, those modified with methacrylic acid, maleic acid, itaconic acid and the like are preferable. For example, GOHSENAL T-330H, T-350, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. Commercially available products such as KL-118, KL-318, KL-506, and KM-118 manufactured by Kuraray can be used.
The modification rate is preferably 0.1 to 8 mol%. As a polymerization degree, 300-2400 are preferable, More preferably, it is 500-2000.

The components of the protective layer (selection of PVA, use of additives, etc.), coating amount, etc. are appropriately selected in consideration of fogging properties, adhesion, scratch resistance, etc. in addition to oxygen barrier properties and development removability. In general, the higher the hydrolysis rate of PVA (that is, the higher the content of the unsubstituted vinyl alcohol unit in the protective layer), the higher the film thickness, the higher the oxygen barrier property, which is preferable in terms of sensitivity. . Further, in order to prevent unnecessary polymerization reaction during production and storage, unnecessary fogging during image exposure, image line thickening, and the like, it is preferable that the oxygen permeability is not too high. Accordingly, the oxygen permeability A at 25 ° C. and 1 atm is preferably 0.2 ≦ A ≦ 20 (cc / m ² · day).

  As another composition of the protective layer, glycerin, dipropylene glycol and the like can be added in an amount corresponding to several mass% with respect to the (co) polymer to provide flexibility. Anionic surfactants such as sodium acid salts; amphoteric surfactants such as alkylaminocarboxylates and alkylaminodicarboxylates; nonionic surfactants such as polyoxyethylene alkylphenyl ethers to the water-soluble polymer compound Several mass% can be added.

In addition, adhesion to the image area, scratch resistance, and the like are extremely important in handling the lithographic printing plate precursor. That is, when a protective layer that is hydrophilic because it contains a water-soluble polymer compound is laminated on an image recording layer that is oleophilic, the protective layer is easily peeled off due to insufficient adhesion, and polymerization is inhibited by oxygen at the peeled portion. It may cause defects such as poor film hardening due to.

  On the other hand, various proposals have been made to improve the adhesion between the image recording layer and the protective layer. For example, JP-A-49-70702 and British Patent Application No. 1303578 disclose an acrylic emulsion, a water-insoluble vinylpyrrolidone-vinyl acetate copolymer, etc. in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing 20 to 60% by mass and laminating on an image recording layer. Any of these known techniques can be used in the present invention.

Furthermore, the protective layer in the lithographic printing plate precursor according to the invention preferably contains an inorganic layered compound for the purpose of improving oxygen barrier properties and surface protective properties of the image recording layer.
Here, the inorganic layered compound is a particle having a thin flat plate shape, for example, the following general formula

A (B, C) _2-5 D ₄ O ₁₀ (OH, F, O) ₂

[However, A is any one of K, Na, and Ca, B and C are any of Fe (II), Fe (III), Mn, Al, Mg, and V, and D is Si or Al. ] Mica groups such as natural mica and synthetic mica represented by

Formula 3 MgO · 4SiO · H ₂ O

Talc, teniolite, montmorillonite, saponite, hectorite, zirconium phosphate and the like represented by

In the mica group, examples of natural mica include muscovite, soda mica, phlogopite, biotite and sericite. Synthetic mica includes non-swellable mica such as fluorine phlogopite mica ₃ (AlSi ₃ O ₁₀ ) F ₂ , potassium tetrasilicon mica KMg _2.5 Si ₄ O ₁₀ ) F ₂ , and Na tetrasilicic mica NaMg _2.5 ( Si ₄ O ₁₀ ) F ₂ , Na or Li teniolite (Na, Li) Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , montmorillonite-based Na or Li hectorite (Na, Li) _1/8 Mg _2/5 Li Examples thereof include swelling mica such as _1/8 Si ₄ O ₁₀ ) F ₂ . Synthetic smectite is also useful.

In the present invention, among the inorganic layered compounds, fluorine-based swellable mica, which is a synthetic inorganic layered compound, is particularly useful. That is, this swellable synthetic mica and swellable viscosity minerals such as montmorillonite, saponite, hectorite, bentonite, etc. have a laminated structure composed of unit crystal lattice layers with a thickness of about 10 to 15 mm, Atomic substitution is significantly greater than other viscous minerals. As a result, the lattice layer is deficient in positive charges, and cations such as Na ⁺ , Ca ²⁺ and Mg ²⁺ are adsorbed between the layers in order to compensate for this. The cations present between these layers are called exchangeable cations and exchange with various cations. In particular, when the cation between the layers is Li ⁺ or Na ⁺ , the bond between the layered crystal lattices is weak because the ionic radius is small, and the layer swells greatly with water. If shear is applied in this state, it will easily cleave and form a stable sol in water. Bentonite and swellable synthetic mica have this tendency and are useful in the present invention, and swellable synthetic mica is particularly preferably used.

As the shape of the inorganic layered compound used in the present invention, from the viewpoint of diffusion control, the smaller the thickness, the better. The plane size is as long as it does not hinder the smoothness of the coated surface or the transmittance of actinic rays. Larger is better. Accordingly, the aspect ratio is 20 or more, preferably 100 or more, particularly preferably 200 or more. The aspect ratio is the ratio of the thickness to the major axis of the particle, and can be measured, for example, from a projected view of the particle by a micrograph. The larger the aspect ratio, the greater the effect that can be obtained.

  As for the particle diameter of the inorganic stratiform compound used in the present invention, the average major axis is 0.3 to 20 μm, preferably 0.5 to 10 μm, particularly preferably 1 to 5 μm. The average thickness of the particles is 0.1 μm or less, preferably 0.05 μm or less, particularly preferably 0.01 μm or less. For example, among inorganic layered compounds, the size of the swellable synthetic mica that is a representative compound is about 1 to 50 nm in thickness and about 1 to 20 μm in surface size.

  When the inorganic layered compound particles having such a large aspect ratio are contained in the protective layer, the coating film strength is improved, and the permeation of oxygen and moisture can be effectively prevented. Deterioration is prevented, and even when stored for a long time under high-humidity conditions, the storage stability of the planographic printing plate precursor does not deteriorate due to changes in humidity, and the storage stability is excellent.

  It is preferable that content of the inorganic stratiform compound in a protective layer is 5/1-1/100 by mass ratio with respect to the quantity of the binder used for a protective layer. Even when a plurality of types of inorganic layered compounds are used in combination, the total amount of these inorganic layered compounds is preferably the above-described mass ratio.

  Next, an example of a general dispersion method of the inorganic stratiform compound used for the protective layer will be described. First, 5 to 10 parts by mass of the swellable layered compound mentioned above as a preferred inorganic layered compound is added to 100 parts by mass of water, and the mixture is thoroughly swelled and swollen, and then dispersed by a disperser. Examples of the disperser used here include various mills that disperse mechanically by applying a direct force, a high-speed stirring disperser having a large shearing force, and a disperser that provides high-intensity ultrasonic energy. Specifically, ball mill, sand grinder mill, visco mill, colloid mill, homogenizer, tisol bar, polytron, homomixer, homo blender, ketdy mill, jet agitator, capillary emulsifier, liquid siren, electrostrictive ultrasonic generator, An emulsifying device having a Paulman whistle can be used. A dispersion of 5 to 10% by mass of the inorganic stratiform compound dispersed by the above method is highly viscous or gelled and has very good storage stability. When preparing a protective layer coating solution using this dispersion, it is preferably prepared by diluting with water and stirring sufficiently, and then blending with a binder solution.

  In addition to the inorganic layered compound, known additives such as a surfactant for improving the coating property and a water-soluble plasticizer for improving the physical properties of the film can be added to the protective layer coating solution. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. A water-soluble (meth) acrylic polymer can also be added. Furthermore, a known additive for improving the adhesion to the image recording layer and the temporal stability of the coating solution may be added to the coating solution.

  The protective layer coating solution thus prepared is applied onto the image recording layer provided on the support and dried to form a protective layer. The coating solvent can be appropriately selected in relation to the binder, but when a water-soluble polymer is used, it is preferable to use distilled water or purified water. The method for applying the protective layer is not particularly limited, and a known method such as the method described in US Pat. No. 3,458,311 or Japanese Patent Publication No. 55-49729 can be applied. . Specific examples of the protective layer include blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, and bar coating.

The coating amount of the protective layer is preferably in the range of 0.05 to 10 g / m ^{2 in} terms of the coating amount after drying. When the inorganic layered compound is contained, 0.1 to 0.5 g / More preferably in the range of m ² , 0.5 to 5 g when no inorganic layered compound is contained.
More preferably, it is in the range of / m ² .

(Back coat layer)
After the surface treatment is performed on the support or after the undercoat layer is formed, a back coat can be provided on the back surface of the support, if necessary.
Examples of the back coat include hydrolysis and polycondensation of organic polymer compounds described in JP-A-5-45885, organometallic compounds or inorganic metal compounds described in JP-A-6-35174. A coating layer made of a metal oxide obtained in this manner is preferred. Among them, it is inexpensive to use a silicon alkoxy compound such as Si (OCH ₃ ) ₄ , Si (OC ₂ H ₅ ) ₄ , Si (OC ₃ H ₇ ) ₄ , Si (OC ₄ H ₉ ) _4. It is preferable in terms of easy availability.

<Exposure>
In the plate making method of the present invention, the lithographic printing plate precursor is exposed imagewise by exposure through a transparent original image having a line image, a halftone dot image or the like, or by laser scanning exposure with digital data. Examples of the exposure light source include a carbon arc, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, a halogen lamp, an ultraviolet light laser, a visible light laser, and an infrared light laser. A laser is particularly preferable, and examples thereof include a semiconductor laser that emits light in the range of 250 to 420 nm, a solid-state laser that emits infrared light in the range of 760 to 1200 nm, and a semiconductor laser. When a laser is used, it is preferable to perform imagewise scanning exposure according to digital data. In order to shorten the exposure time, it is preferable to use a multi-beam laser device.
These lasers are used by being mounted on a so-called platesetter that performs imagewise exposure under computer control.

In the present invention, the development process may be performed immediately after the exposure process, but a heat treatment process (preheating) may be provided between the exposure process and the development process. This heat treatment has the effect of improving the printing durability and further improving the uniformity of the image curing degree within the plate surface, and the conditions can be appropriately set within the range where these effects are present. Examples of the heating means include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, a Wisconsin oven, and the like. Specifically, it can be carried out by holding the plate surface temperature in the range of 70 to 150 ° C. for 1 second to 5 minutes. Preferably, the temperature is 80 ° C to 140 ° C for 5 to 1 minute, more preferably 90 ° C to 130 ° C for 10 to 30 seconds. This range is preferable in that the above effect can be obtained efficiently and there is no adverse effect such as deformation of the printing plate due to heat.
At this time, it is preferable that the heat treatment means used in the heat treatment step and the developing device used in the development treatment step are connected to each other and automatically continuously processed. Specifically, it is a plate making line in which a plate setter and a developing device are coupled by a conveying means such as a conveyor. A heat treatment means may be inserted between the plate setter and the developing device, and the heating means and the developing device may be integrated.

When the printing plate to be used is easily affected by ambient light in the work environment, it is preferable that the plate making line is shielded by a filter or a cover. Of course, when there is no heat treatment, the exposure means is directly connected to the development processing means, and continuous processing is automatically performed.
In the present invention, after the exposure step, development may be carried out immediately, but a water washing step (pre-water washing) for the purpose of removing the protective layer described above between the exposure step and the development step. There may be a process.
Both of the above two steps may be included, or one of them may be introduced.
After finishing the development process and forming an image as described above, the entire surface may be exposed with an actinic ray such as ultraviolet light to accelerate the curing of the image portion. Examples of the light source for the entire surface exposure include a carbon arc lamp, a mercury lamp, a gallium lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, and various laser lights. Further, in order to obtain a sufficient printing durability, the overall exposure is preferably at least 10 mJ / cm ² or more, more preferably 100 mJ / cm ² or more.

Furthermore, heating may be performed simultaneously with the entire surface exposure, and further improvement in printing durability is recognized by heating. Examples of the heating device include a conventional convection oven, an IR irradiation device, an IR laser, a microwave device, a Wisconsin oven, and the like. At this time, the plate surface temperature is preferably 30 to 150 ° C, more preferably 35 to 130 ° C, and still more preferably 40 to 120 ° C.
In the present invention, it is preferable to dry the lithographic printing plate precursor on which an image is formed by performing the above-described development process and additionally a preheating or pre-water washing process in order to facilitate subsequent handling. Examples of the drying method include natural drying left in a room, hot air drying, and using a dryer attached to a gum coater or an automatic processor.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

Preparation of support body To remove rolling oil on the surface of an aluminum plate (material 1050) having a thickness of 0.3 mm, after performing a degreasing treatment at 50 ° C. for 30 seconds using a 10 mass% sodium aluminate aqueous solution, the bristle diameter The aluminum surface was grained using ^three 0.3 mm bundled nylon brushes and a pumice-water suspension (specific gravity 1.1 g / cm ³ ) having a median diameter of 25 μm and washed well with water. This plate was etched by being immersed in a 25 mass% sodium hydroxide aqueous solution at 45 ° C for 9 seconds, washed with water, further immersed in 20 mass% nitric acid at 60 ° C for 20 seconds, and washed with water. The etching amount of the grained surface at this time was about 3 g / m ² .

Next, an electrochemical roughening treatment was performed continuously using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass nitric acid aqueous solution (containing 0.5% by mass of aluminum ions) and a liquid temperature of 50 ° C. The AC power source waveform is electrochemical roughening treatment using a trapezoidal rectangular wave alternating current with a time ratio TP of 0.8 msec until the current value reaches a peak from zero, a duty ratio of 1: 1, and a trapezoidal rectangular wave alternating current. Went. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the peak current value, and 5% of the current flowing from the power source was shunted to the auxiliary anode.
The amount of electricity in the nitric acid electrolysis was 175 C / dm ² when the aluminum plate was the anode.
Then, water washing by spraying was performed.

Next, a 0.5% by mass hydrochloric acid aqueous solution (containing 0.5% by mass of aluminum ions) and an electrolytic solution having a liquid temperature of 50 ° C. and nitric acid electrolysis under the condition of an electric quantity of 50 C / dm ² when the aluminum plate is an anode. In the same manner as above, an electrochemical surface roughening treatment was performed, followed by washing with water by spraying. The plate was provided with a DC anodized film of 2.5 g / m ² at a current density of 15 A / dm ² using 15% by mass sulfuric acid (containing 0.5% by mass of aluminum ions) as an electrolytic solution, then washed with water and dried. The centerline average roughness (Ra) of this substrate was measured using a needle having a diameter of 2 μm and found to be 0.51 μm.

Next, the following undercoat liquid (1) was applied so that the dry coating amount was 10 mg / m ² to prepare a support used in the following experiments.

Undercoat liquid (1)
・ Undercoat compound (1) below 0.017g
・ Methanol 9.00 g
・ Water 1.00g

<Preparation of lithographic printing plate precursor A>
The image recording layer coating solution (1) was bar coated on the support provided with the undercoat layer and then oven dried at 100 ° C. for 75 seconds to form an image recording layer having a dry coating amount of 1.0 g / m ^2. Then, a protective layer coating solution (1) having the following composition was further applied thereon using a bar so that the coating amount at the time of drying was 1.0 g / m ^2, and then the condition was 100 ° C. for 90 seconds. And dried in an oven to obtain a lithographic printing plate precursor A.
The image recording layer coating solution (1) was obtained by mixing and stirring the following photosensitive solution (1) and microcapsule solution (1) immediately before coating.

Photosensitive solution (1)
-Binder polymer (1) 0.162g
・ The following polymerization initiator (1) 0.100 g
・ The following infrared absorber (1) 0.020 g
・ Polymerizable compound, Aronix M-315 (manufactured by Toa Gosei Co., Ltd.) 0.385 g
-0.044 g of the following fluorosurfactant (1)
・ Methyl ethyl ketone 1.091g
・ 1-methoxy-2-propanol 8.609g

Microcapsule liquid (1)
-Microcapsules synthesized as follows (1) 2.640 g
・ Water 2.425g

Synthesis of Microcapsule (1) As oil phase components, trimethylolpropane and xylene diisocyanate adduct (Mitsui Takeda Chemical Co., Ltd., Takenate D-110N, 75% ethyl acetate solution) 10 g, Aronix M-215 (Toho) Synthetic Co., Ltd. (6.00 g) and Pionein A-41C (Takemoto Yushi Co., Ltd.) 0.12 g were dissolved in ethyl acetate 16.67 g. As an aqueous phase component, 37.5 g of a 4 mass% aqueous solution of PVA-205 was prepared. The oil phase component and the aqueous phase component were mixed and emulsified for 10 minutes at 12000 rpm using a homogenizer. The obtained emulsion was added to 25 g of distilled water, stirred at room temperature for 30 minutes, and then stirred at 40 ° C. for 2 hours. The microcapsule solution thus obtained was diluted with distilled water so that the solid content concentration was 15% by mass. The average particle size was 0.2 μm.

Protective layer coating solution (1)
・ 88g of water
・ Polyvinyl alcohol PVA105 (Kuraray Co., Ltd.) 10g
・ Polyethylene glycol (molecular weight 2000) 2g
・ 1g of the following surfactant

<Preparation of lithographic printing plate precursor B>
An image recording layer coating solution (2) having the following composition was bar-coated on the above support, followed by oven drying at 100 ° C. for 60 seconds to form an image recording layer having a dry coating amount of 1.4 g / m ^2. A protective layer coating solution (1) having the above composition was applied on the coating composition so that the dry coating mass was 0.5 g / m ² and dried at 120 ° C. for 1 minute to obtain a lithographic printing plate precursor B.

Image recording layer coating solution (2)
・ 2.0 g of the above binder polymer (1)
・ Polymerizable compound 1.5g
Isocyanuric acid EO-modified triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-315)
-Compound represented by the following (1) 0.15 g
-Compound represented by (2) below 0.20 g
・ 0.4 g of the compound represented by the following (3)
・ Ethyl violet 0.1g
・ Thermal polymerization inhibitor 0.1g
N-nitrosophenylhydroxylamine aluminum salt 0.02 g of the above water-soluble fluorosurfactant (1)
・ Tetraethylamine hydrochloride 0.06g
・ 17.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 19.0g

<Preparation of lithographic printing plate precursor C>
An image recording layer coating solution (3) having the following composition was bar-coated on the support provided with the undercoat layer, followed by oven drying at 70 ° C. for 60 seconds, and an image having a dry coating amount of 1.1 g / m ² . A recording layer is formed, and a protective layer coating solution (2) having the following composition is coated thereon using a bar so that the dry coating amount is 0.2 g / m ^2, and then dried at 125 ° C. for 70 seconds. Thus, a lithographic printing plate precursor C was obtained.

[Image recording layer coating solution (3)]
-Binder polymer (1) with the above structure (average molecular weight 80,000) 0.54 g
・ Polymerizable compound 0.40g
Isocyanuric acid EO-modified triacrylate (manufactured by Toa Gosei Co., Ltd., Aronix M-315)
・ Polymerizable compound Ethoxylated trimethylolpropane triacrylate 0.08 g
(Nippon Kayaku Co., Ltd., SR9035, EO addition mole number 15, molecular weight 1000)
・ The following sensitizing dye (1) 0.06 g
・ The following polymerization initiator (2) 0.18 g
・ The following chain transfer agent (1) 0.07 g
・ 0.40 g of ε-phthalocyanine pigment dispersion
(Pigment: 15 parts by mass, dispersant Binder polymer (1): 10 parts by mass, solvent cyclohexanone / methoxypropyl acetate / 1-methoxy-2-propanol = 15 parts by mass / 20 parts by mass / 40 parts by mass)
・ Thermal polymerization inhibitor 0.01g
N-nitrosophenylhydroxylamine aluminum salt-The above water-soluble fluorosurfactant (1) 0.001 g
・ Polyoxyethylene-polyoxypropylene condensate 0.04g
(Asahi Denka Kogyo Co., Ltd., Pluronic L44)
・ Tetraethylamine hydrochloride 0.01g
・ 3.5 g of 1-methoxy-2-propanol
・ Methyl ethyl ketone 8.0g

[Protective layer coating solution (2)]
・ The following mica dispersion (1) 13.0 g
・ Polyvinyl alcohol (Goseiran L-3266 manufactured by Nippon Synthetic Chemical Industry) 1.3g
-Sodium 2-ethylhexyl sulfosuccinate 0.2g
・ Poly (vinyl pyrrolidone / vinyl acetate (1/1)) molecular weight 70,000 g
・ Surfactant (Emalex 710, manufactured by Nippon Emulsion Co., Ltd.) 0.05g
・ 133g of water

(Preparation of mica dispersion (1))
To 368 g of water, 32 g of synthetic mica (“Somasif ME-100”: manufactured by Co-op Chemical Co., Ltd., aspect ratio: 1000 or more) is added and dispersed using an homogenizer until the average particle size (laser scattering method) becomes 0.5 μm. A mica dispersion (1) was obtained.
Furthermore, when the oxygen transmission rate of the protective layer was measured under the following conditions, the oxygen transmission rate of the protective layer was 2.0 ml / (m ² · day · atom).

(Measurement of oxygen permeability)
A protective layer (oxygen barrier layer) is applied to the surface of a photographic paper having a thickness of about 200 μm and coated on both sides with polyethylene having a thickness of about 20 μm, dried, and a measurement sample. Was made. The oxygen permeability of the photographic paper measured in advance was about 700 ml / (m ² · day · atom) under the following measurement conditions, and was a value that could be sufficiently ignored when measuring the permeability in the oxygen barrier layer.
Using the sample thus obtained, according to the gas permeability test method described in JIS K7126B and ASTM D3985, oxygen permeation was performed at 25 ° C. and 60% RH using OX-TRAN 2/20 manufactured by Mocon. The rate [ml / (m ² · day · atom)] was measured.

<Creation of lithographic printing plate precursor D>
The polymerizable compound Aronix M-315 of the image recording layer coating solution (1) was replaced with PLEX6661-O (Rohm GmbH & KG, 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-dia. A lithographic printing plate precursor D was obtained in the same manner as the lithographic printing plate precursor A except that the binder polymer (1) was replaced with the following polymer instead of the hexadecane-1,16-diyldimethacrylate).

<Creation of lithographic printing plate precursor E>
The polymerizable compound Aronix M-315 in the image recording layer coating solution (3) was replaced with PLEX6661-O (Rohm GmbH & KG, 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-dia. A lithographic printing plate precursor E was obtained in the same manner as the lithographic printing plate precursor C, except that the binder polymer was changed to the following polymer in place of the hexadecane-1,16-diyldimethacrylate).

1. Preparation of treatment liquids Treatment liquids Nos. 1 to 15 having the compositions shown in Table 1 below, each having a concentration of each component in mass%, were produced. The pH of the treatment liquid was adjusted to the pH shown in Table 1 using phosphoric acid or sodium hydroxide.

2. Platemaking evaluation (Experiments No. 1 to 20)
Processing conditions: exposure → preheating → development processing → drying The obtained lithographic printing plate precursor was processed in the order of exposure with a setter, preheating with an automatic processor, development processing, and drying. Here, the setter used for exposure is changed with the sensitive material. The relationship between the setter and the lithographic printing plate precursor used is as shown below.

Light source (setter) used for exposure Sensitive infrared semiconductor laser Planographic printing plate precursor A, D
(Trendsetter3244VX manufactured by Creo)
405 nm semiconductor laser Planographic printing plate precursors B, C, E

The exposure conditions of the setter used are described below.
Trend setter 3244VX manufactured by Creo Co., Ltd. Image-wise exposure was performed under the conditions of an output of 9 W, an outer drum rotating speed of 210 rpm, and a resolution of 2400 dpi with a water-cooled 40 W infrared semiconductor laser.
405 nm semiconductor laser: Image exposure was carried out using a Violet semiconductor laser plate setter Vx9600 manufactured by FUJIFILM Electronic Imaging Ltd (equipped with InGaN semiconductor laser 405 nm ± 10 nm emission / output 30 mW). The image was drawn using a FM screen (TAFFETA 20) manufactured by Fuji Photo Film Co., Ltd. with a resolution of 2438 dpi, and a 35% flat screen was drawn with a plate exposure of 0.09 mJ / cm ² .

Next, the exposed light-sensitive material was placed in an oven within 30 seconds and subjected to heat treatment. In the oven, hot air was blown to heat the entire surface of the lithographic printing plate precursor. The heating time was 110 ° C. for 15 seconds. Then, it developed with the automatic processor shown in FIG. 1 using the developing solution shown in Table 1. In the automatic developing machine, the temperature of the processing solution in the developing tank was 30 ° C., and the passage time of the developing tank was 20 seconds. The planographic printing plate precursor discharged from the developing tank was dried with a dryer.
Thus, the developability was evaluated using the lithographic printing plate made as a plate.
Further, as an evaluation of the non-image area printing stain and processing unevenness with the fatigue liquid, after running the unexposed plate so that the processing amount of the printing plate becomes 10 m ² per liter of the developer in the developing tank, The image exposed plate was processed. By printing the treated plate, the non-image area printing stain with the fatigue liquid was evaluated, and the processing unevenness was evaluated by observing the developability of the plate.

Evaluation of developability ×: Development is impossible at all.
Δ: Slightly but thin and residual film. A level that will not interfere with printing.
○: Basically there is no residual film, but there is a rare level where a thin film may be formed.
A: Level without any residual film.

Evaluation of processing unevenness
×: Shading unevenness is severe.
Δ: Light and dark unevenness exists, but there is no problem even if printing is performed.
○: In very rare cases, there is uneven density.
A: No shade unevenness.

Evaluation of Printability with Fatigue Liquid Non-image area contamination with a fatigue liquid was evaluated. The plate treated with the above-mentioned fatigue fluid was attached to a cylinder of a printing machine SOR-M manufactured by Heidelberg. Fountain solution (Ecolity-2 (dampening solution manufactured by Fuji Photo Film Co., Ltd.) diluted to 2% with water) and TRANS-G (N) ink ink (manufactured by Dainippon Ink & Chemicals, Inc.) After supplying dampening water and ink, 500 sheets were printed at a printing speed of 6000 sheets per hour. If it is not dirty, it is 5 points, and if it is not dirty, it is 1 point.
The evaluation results are described in a five-step evaluation. It is shown that the degree is improved as the score is increased with 4 points or more being an acceptable level.

The results are shown in Table 2.

  From the above results, the lithographic printing plate development processing solution and the lithographic printing plate making method of each example according to the present invention are more developable, processing unevenness, and stain resistance in a fatigue developer than the comparative examples. Is clearly superior.

1 shows a schematic structure of an example of an automatic developing apparatus that can be used for developing with a gum solution.

Explanation of symbols

1: Rotating brush roll 2: Receiving roll 3: Transport roll 4: Transport guide plate 5: Spray pipe 6: Pipe line 7: Filter 8: Plate feeding table 9: Discharge plate 100: Developer tank 101: Circulation pump 102: Plate

Claims (4)

A lithographic printing plate developing solution comprising a compound represented by the following formula (I), a water-soluble polymer compound, and an azole compound, and having a pH of 2 to 8.

(In the formula (I), R 1 and R 2 each independently represent H or an alkyl group, R 3 represents an alkyl group or a group containing ethylene oxide, and A represents a carboxylate anion, a sulfonate anion, or a phosphone. It is a group containing an acid anion.)   The azole compound is α- (4-chlorophenyl) -α- (1-cyclopropylethyl) -1H-1,2,4-triazole-1-ethanol, -α- [2- (4-chlorophenyl) ethyl]- α- (1,1-dimethylethyl) -1H-1,2,4-triazole-1-ethanol and 1-[[2- (2,4-dichlorophenyl) -4-n-propyl-1,3-dioxolane The lithographic printing plate developing solution according to claim 1, wherein the lithographic printing plate developing solution is selected from azole compounds consisting of -2-yl] methyl] -1H-1,2,4-triazole.   The lithographic printing plate precursor having an image recording layer and a protective layer containing polyvinyl alcohol on the support is exposed imagewise to cure the image recording layer of the exposed portion, and then the method according to claim 1 or 2. A lithographic printing plate making method comprising developing with a processing solution.   The lithographic printing plate making method according to claim 3, wherein the polyvinyl alcohol is acid-modified polyvinyl alcohol.

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