JP2013200464A - Photosensitive lithographic printing plate material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate material that is suitable for chemical-less development containing substantially no alkali agent, and has excellent printing durability.SOLUTION: A photosensitive lithographic printing plate material includes at least a hydrophilic layer and a photo-curable photosensitive layer in this order on a support; and the hydrophilic layer contains gelatin that is modified with a compound including a polymerizable double bond group and an epoxy group in one molecule.

Description

  The present invention relates to a photosensitive lithographic printing plate material having at least a hydrophilic layer on a support. More specifically, the present invention relates to a photosensitive lithographic printing plate material which is suitable for chemicalless development containing substantially no alkali agent and has excellent printing durability.

  There are various fields of application as a photosensitive composition utilizing photopolymerization. For example, in applications such as photoresists and lithographic printing plates, development processing using an organic solvent or a strong alkaline reagent has recently been developed with water or the like. A possible system is being developed. Especially in relation to lithographic printing plates, computer-to-plate (CTP) technology has been developed that outputs digital data produced on a computer directly onto a printing plate without outputting it on film. Development of various plate setters equipped with these lasers and photosensitive lithographic printing plate materials compatible with these platesetters is ongoing.

  Important issues or requests that have been raised with the spread of the CTP method include various points related to development processing. In the normal CTP method, the photosensitive lithographic printing plate material is laser-exposed and the non-image area is eluted with an alkaline developer, and is subjected to printing through a water washing and gumming process. However, alkaline developers are harmful to the human body, and sufficient care and management are required for their handling and storage. In addition, the purchase cost and the cost related to waste liquid treatment impose a great burden on the user, and in addition, the pH, temperature, etc. must be carefully managed as the liquidity of the alkaline developer. Handling was complicated.

  There has been proposed a photosensitive composition that avoids the use of such an alkaline developer and can be developed with water or the like. For example, JP-A-5-27437 (Patent Document 1) discloses an aqueous photosensitive composition containing a carboxyl group-containing resin, an amine compound, a photocurable unsaturated compound, a photopolymerization initiator, and water. Further, JP 2003-215801 A (Patent Document 2), JP 2008-265297 A (Patent Document 3) and the like disclose a cationic or anionic water-soluble polymer having a polymerizable double bond group in the side chain. A photosensitive composition that can be developed with water and a photosensitive lithographic printing plate material using the same is disclosed.

  Further, as a hydrophilic layer suitable for such a photosensitive lithographic printing plate material, the above-mentioned Patent Document 3 contains a water-soluble polymer, a cross-linking agent for cross-linking the water-soluble polymer, and colloidal silica on a support. In addition, a photosensitive lithographic printing plate material having a hydrophilic layer in which the ratio of the water-soluble polymer and colloidal silica is specified is disclosed. Furthermore, in JP-A-2009-226596 (Patent Document 4), the hydrophilic layer is at least water-soluble. A photosensitive lithographic printing plate material containing a photosensitive polymer and inorganic fine particles and having a film surface pH value of the hydrophilic layer of 7.0 or more is disclosed. Such a photosensitive lithographic printing plate material enables development with water or the like, but depending on the printing conditions, the image area may be partially lost and sufficient printing durability may not be obtained. It was done.

  As a method for improving the printing durability of a photosensitive lithographic printing plate material that can be developed with water or the like, for example, in JP 2010-237560 A (Patent Document 5), a photosensitive material having a hydrophilic layer containing a photosensitive polymer is disclosed. A lithographic printing plate material is disclosed, and JP 2010-237561 A (Patent Document 6) discloses a photosensitive lithographic printing plate material having a hydrophilic layer containing a photopolymerization initiator. (Patent Document 7) discloses a photosensitive lithographic printing plate material having a hydrophilic layer containing vapor-phase process silica, and these publications disclose a water-soluble resin contained in the hydrophilic layer as a water-soluble resin. Although (meth) acrylic acid, polyvinyl alcohol, gelatin and the like are described, they are not satisfactory.

  As another technique for improving printing durability, JP 2000-29203 A (Patent Document 8) has an ethylenic double bond capable of addition polymerization between a support and a photocurable photosensitive layer. A negative photosensitive lithographic printing plate material having an intermediate layer containing a compound obtained by hydrolyzing and dehydrating and condensing a silane coupling agent is disclosed, and Japanese Patent Application Laid-Open No. 2005-125649 (Patent Document 9) and Japanese Patent Application Laid-Open No. 2005-238816. (Patent Document 10) discloses that a layer containing a monomer or copolymer having an ethylenically unsaturated bond group that interacts with the support surface is provided between the support and the photocurable photosensitive layer. Have been described.

JP-A-5-27437 JP 2003-215801 A JP 2008-265297 A JP 2009-226596 A JP 2010-237560 A JP 2010-237561 A JP2011-203401A JP 2000-29203 A Japanese Patent Laying-Open No. 2005-125749 JP 2005-238816 A

  An object of the present invention is to provide a photosensitive lithographic printing plate material which is suitable for chemicalless development substantially free of an alkali agent and has excellent printing durability.

The above-described problems of the present application have been solved by the following invention.
(1) A photosensitive lithographic printing plate material having at least a hydrophilic layer and a photocurable photosensitive layer in this order on a support, wherein the hydrophilic layer has a polymerizable double bond group and an epoxy group in one molecule. A photosensitive lithographic printing plate material comprising gelatin modified with a compound having the same.

  According to the present invention, it is possible to provide a photosensitive lithographic printing plate material which is suitable for chemicalless development substantially free of an alkali agent and has excellent printing durability.

Hereinafter, the present invention will be described in detail.
The hydrophilic layer of the present invention contains gelatin modified with a compound having a polymerizable double bond group and an epoxy group in one molecule (hereinafter also referred to as modified gelatin of the present invention).

  Examples of the compound having a polymerizable double bond group and an epoxy group in one molecule include (meth) acrylic acid glycidyl, (meth) acrylic acid-β-methylglycidyl, (meth) acrylic acid-β-ethylglycidyl, (Meth) acrylic acid-β-propylglycidyl, α-ethylacrylic acid-β-methylglycidyl, (meth) acrylic acid-3-methyl-3,4-epoxybutyl, (meth) acrylic acid-3-ethyl-3 , 4-epoxybutyl, (meth) acrylic acid-4-methyl-4,5-epoxypentyl, (meth) acrylic acid-5-methyl-5,6-epoxyhexyl, glycidyl vinyl ether, etc. ) Glycidyl acrylate is preferred. These compounds can also be used in combination.

  As the gelatin modified with the compound having a polymerizable double bond group and an epoxy group in one molecule as described above, any gelatin made from animal collagen can be used, but pig skin, cow skin, cow bone Gelatin made from collagen as a raw material is preferred. Further, the type of gelatin is not particularly limited, but lime-processed gelatin, acid-processed gelatin, gelatin derivatives (for example, JP-B Nos. 38-4854, 39-5514, 40-12237, and 42-26345). U.S. Pat.Nos. 2,525,753, 2,594,293, 2,614,928, 2,763,639, 3,118,766, 3,132,945, 3,186,843, 3,332,553, British Patents 861,414, The gelatin derivatives described in No. 1033189 etc. can be used alone or in combination. Further, the gelatin jelly strength (based on the PAGI method, Bloom-type jelly strength meter) is preferably 150 g or more, particularly preferably 200 g or more.

  For example, the gelatin modification described above is performed by mixing an aqueous solution in which gelatin is dissolved with the compound having a polymerizable double bond group and an epoxy group in one molecule (the pH of this mixture is adjusted to 4.0 to 8.0). The mixture can be modified by heating at a temperature of preferably 50 ° C. or higher, more preferably 60 ° C. or higher. The upper limit is preferably 90 ° C. or lower. The heating time is preferably 30 minutes or more, more preferably 60 minutes or more. When the mixture is heated in this manner, the low molecular components in the mixture decrease, and eventually the majority of them become polymer components. This can be confirmed, for example, by quantifying the residual amount of the low molecular component using gas chromatography. The amount of the compound having a polymerizable double bond group and an epoxy group in one molecule is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% with respect to 100 parts by mass of gelatin. More preferably, it is mass%.

  The hydrophilic layer can contain other hydrophilic binder in addition to the modified gelatin of the present invention described above. Examples of such hydrophilic binders include natural products such as starch, seaweed mannan, agar, and algae such as sodium alginate, mannan, pectin, tragacanth gum, caraya gum, xanthine gum, guarbin gum, locust bin gum, gum arabic, etc. Plant mucilage, dextran, glucan, homopolysaccharide such as xanthan gum and levan, microbial mucilage such as heteropolysaccharide such as succinoglucan, pullulan, curdlan and xanthan gum, glue, unmodified gelatin, casein and collagen, etc. Examples include proteins, chitin and derivatives thereof. Semi-natural products (semi-synthetic products) include cellulose derivatives, modified gums such as carboxymethyl guar gum, cultured starches such as dextrin, processed starches such as oxidized starches and esterified starches. . On the other hand, synthetic products include polyvinyl alcohol, partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol, modified polyvinyl alcohols such as polyvinyl methyl ether, polyvinyl ethyl ether, and polyvinyl isobutyl ether, polyacrylates, and polyacrylate ester partial saponified products. , Polymethacrylic acid derivatives and polymethacrylic acid derivatives such as polymethacrylic acid salts and polyacrylamides, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, vinylpyrrolidone / vinyl acetate copolymer, carboxyvinyl polymer, styrene / maleic acid copolymer Examples thereof include a polymer and a styrene / crotonic acid copolymer.

  The amount of the other hydrophilic binder described above is preferably 100% by mass or less, more preferably 60% by mass or less, and 30% by mass or less with respect to 100 parts by mass of the modified gelatin of the present invention. Is particularly preferred.

  In the present invention, the hydrophilic layer preferably contains an inorganic filler, and the content of the hydrophilic binder contained in the hydrophilic layer (the modified gelatin content of the present invention described above, or the modified gelatin of the present invention and other hydrophilic properties) The combined content of the binder is preferably 5 to 30% by mass and more preferably 10 to 25% by mass with respect to 100 parts by mass of the total inorganic filler. If it exceeds 30% by mass, the filler filling density is lowered and sufficient hydrophilicity cannot be imparted, and the soil resistance and the net resistance may be lowered. On the other hand, if it is less than 5% by mass, the handling property of the coating liquid may be lowered, or cracks may occur after forming the hydrophilic layer.

  Examples of the inorganic filler contained in the hydrophilic layer in the present invention include calcium carbonate, magnesium carbonate, zinc oxide, titanium dioxide, barium sulfate, aluminum hydroxide, zinc hydroxide, colloidal silica, pore silica, and kaolin. Of these, titanium dioxide, barium sulfate and aluminum hydroxide are preferred. Moreover, it is preferable not to use silicon-containing compounds such as colloidal silica, fine pore silica, and kaolin, and the content of these silicon-containing compounds should be 5% by mass or less based on the total inorganic filler in the hydrophilic layer. It is preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

  Titanium dioxide preferably used as the inorganic filler may be either a rutile type or an anatase type, and the production method is not limited to either the sulfuric acid method or the chlorine method. You may use them individually or in mixture. Furthermore, from the viewpoint of dispersion stability and other functionality, it is possible to selectively use those subjected to various surface treatments. Examples of commercially available titanium dioxide include SR-1, R-650, R-5N, R-7E, R-3L, A-110, and A-190 from Sakai Chemical Industry Co., Ltd. ) From Taipei R-580, R-930, A-100, A-220, CR-58, Titanium Industry Co., Ltd., Kronos KR-310, KR-380, KA-10, KA -20 etc., Teica Co., Ltd., Titanics JR-301, JR-600A, JR-800, JR-701 etc., DuPont Co., Ltd. Taipure R-900, R-931 etc. are mentioned.

  As barium sulfate, it is preferable to use precipitated barium sulfate produced by adding a sulfate aqueous solution to a barium chlorine solution and chemically precipitating. Precipitated barium sulfate is commercially available, for example, as “Variace” from Sakai Chemical Industry Co., Ltd., having various particle diameters or surface-treated ones, but any of them can be used in the present invention.

  Aluminum hydroxide mixes bauxite, which is an ore containing alumina, with caustic soda or sodium aluminate solution, extracts the alumina component under high temperature and high pressure conditions, separates and removes red mud as a dissolution residue from the extract, A clarified sodium aluminate solution is obtained. Thereafter, seeds can be added to the solution to crystallize aluminum hydroxide, and the obtained aluminum hydroxide can be pulverized. Various grades of aluminum hydroxide are commercially available from Showa Denko Co., Ltd. as “Hijilite”, and any grade can be used in the present invention.

  The particle size distribution of the inorganic filler contained in the hydrophilic layer has peaks in at least two places of a range of 0.2 μm or more and less than 0.6 μm and a range of 0.6 μm or more and less than 1.5 μm. When the distribution frequency of the inorganic filler existing in the range of less than 6 μm is fx and the distribution frequency of the inorganic filler existing in the range of 0.6 μm or more and less than 1.5 μm is fy, the fx / fy ratio is 1.5 or more. The distribution frequency fy is preferably 25% or more. The fx / fy ratio is preferably 2.0 or more. The upper limit is desirably less than 3.5. As a result, a photosensitive lithographic printing plate material that is particularly excellent in printing durability and background stain resistance can be obtained. In the above-mentioned range, for example, when a plurality of peaks are present in the range of 0.2 μm or more and less than 0.6 μm, the distribution frequency fx may be obtained with the higher peak. In the case where the height of the recess between two peaks is 60% or more of the higher peak, it is regarded as one peak in the present invention.

  The particle size distribution in the present invention is a volume-based particle size distribution, which is an index indicating what kind of particle size the sample particle group to be measured is and what ratio is configured, and is generally known It can be measured by the method. For example, a sieving method, a Coulter method (Coulter principle), a dynamic light scattering method, an image analysis method, a laser diffraction scattering method, etc. are known as the measuring method. In the present invention, the particle size to be measured and reproducibility are known. From the viewpoint of operability and the like, a laser diffraction / scattering method is preferably used, and for example, it can be measured by LA-920 (laser diffraction / scattering type particle size distribution measuring device) manufactured by HORIBA. The distribution frequency can be obtained as a distribution of the existence ratio for each size (particle diameter) based on the measurement result.

  The particle size distribution and distribution frequency in the present invention are measured by measuring the inorganic filler dispersed in the coating solution, or by measuring the inorganic filler in a solution obtained by re-dissolving the dried coating film of the applied hydrophilic layer with an alkali. You can ask for it. As will be described later, in the present invention, two or more kinds of inorganic fillers can be used together. However, in the laser diffraction scattering method preferably used in the present invention, the light intensity distribution pattern is obtained from the Fraunhofer diffraction theory and the Mie scattering theory. Therefore, a refractive index specific to the object is required, and it is difficult to accurately measure the particle size distribution and distribution frequency of a coating liquid containing two or more inorganic fillers having different refractive indexes. However, in such a case, the particle size distribution and distribution frequency of each inorganic filler alone are measured in advance, and two or more kinds of inorganic fillers are added by multiplying the obtained measurement result by the addition ratio in the coating liquid as a coefficient. The particle size distribution and distribution frequency of the coating liquid used in combination can be determined.

  The inorganic filler contained in the hydrophilic layer may be one type of filler as long as it is an inorganic filler having the above particle size distribution, but when two or more types are used in combination, the above particle size distribution can be obtained relatively easily. Therefore, it is preferable. Among them, it is preferable to use a combination of an inorganic filler having an average primary particle size of 0.1 μm or more and less than 0.6 μm and an inorganic filler having an average primary particle size of 0.6 μm or more and less than 2.0 μm. You may use an inorganic filler in combination with 3 types and 4 types further. The addition amount of the inorganic filler is preferably 60% by mass or more, more preferably 70% by mass or more, based on the total solid content of the hydrophilic layer.

  In the present invention, the hydrophilic layer preferably contains a crosslinking agent. As the crosslinking agent to be used, for example, melamine resin, polyisocyanate compound, aldehyde compound, silane compound, chromium alum, divinyl sulfone and the like can be suitably used, but a particularly preferred crosslinking agent is divinyl sulfone. The blending amount of the crosslinking agent is preferably 5 to 35% by mass, more preferably 10 to 25% by mass, based on the solid content of the hydrophilic binder. As a method for adding the crosslinking agent, there are a method of adding the hydrophilic layer coating liquid when it is manufactured, a method of adding it in-line immediately before coating, and any method may be used.

  In order to sufficiently crosslink the hydrophilic layer, for example, 0.5 to 0.5 at a temperature of 30 to 60 ° C., preferably 40 to 50 ° C., between the formation of the hydrophilic layer and the application of the photopolymerizable photosensitive layer. It is preferable to perform a heating treatment for 10 days, preferably 1 to 7 days. Even if the hydrophilic layer is exposed by the development process after the exposure by such a heating process, and is subjected to printing as a non-image part at the time of printing, it is natural that the printability is sufficient in terms of scratch resistance. Can be expressed.

  The photocurable photosensitive layer of the photosensitive lithographic printing plate material of the present invention preferably contains a photopolymerization initiator and a compound having a polymerizable double bond group.

  As the photopolymerization initiator contained in the photocurable photosensitive layer, conventionally known compounds can be used. For example, trihaloalkyl-substituted compounds (for example, s-triazine compounds and oxadiazole derivatives as trihaloalkyl-substituted nitrogen-containing heterocyclic compounds, trihaloalkylsulfonyl compounds), organic boron salts, hexaarylbiimidazoles, titanocene compounds, thios Examples thereof include compounds and organic peroxides. Among these photopolymerization initiators, trihaloalkyl-substituted compounds and organic boron salts are particularly preferably used. More preferably, a combination of a trihaloalkyl-substituted compound and an organic boron salt is used. A combination of a trihaloalkyl-substituted compound and an organic boron salt is preferable because the generated radical species are stabilized and the sensitivity can be further improved.

  The trihaloalkyl-substituted compound that is a photopolymerization initiator is specifically a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. Preferred examples include the trihaloalkyl group. S-triazine derivatives and oxadiazole derivatives are exemplified as compounds in which is bonded to a nitrogen-containing heterocyclic group, or a trihaloalkylsulfonyl in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocyclic ring via a sulfonyl group Compounds.

  Particularly preferred examples of compounds in which a trihaloalkyl group is bonded to a nitrogen-containing heterocyclic group and trihaloalkylsulfonyl compounds are shown below.

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

In the formula, each of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, and represents an alkyl group, aryl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group or heterocyclic group. Represent. Of these, it is particularly preferred that one of R ₁ , R ₂ , R ₃ and R ₄ is an alkyl group and the other substituent is an aryl group.

  Examples of the cation constituting the organic boron salt include alkali metal ions and onium compounds, but onium salts are preferred, for example, ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and triarylalkyls. Examples thereof include phosphonium salts such as phosphonium salts. Examples of particularly preferred organic boron salts are shown below.

  The content of the photopolymerization initiator as described above is preferably in the range of 1 to 50% by mass and more preferably in the range of 5 to 30% by mass with respect to the compound having a polymerizable double bond group described later. It is preferable.

  The compound having a polymerizable double bond group contained in the photocurable photosensitive layer is a polymer compound having a polymerizable double bond group or a low molecular compound having a polymerizable double bond group. From the viewpoint of photopolymerization efficiency, it is preferable to use a polymer compound having a group and a low molecular compound having a polymerizable double bond group in combination.

  The polymer compound having a polymerizable double bond group will be described. The polymer compound having a polymerizable double bond group is a polymer compound formed by an arbitrary repeating unit, and a polymer compound in which a polymerizable double bond group is bonded to a side chain through an arbitrary linking group. It is preferable that Among them, a polymer compound having a vinyl group as a reactive double bond group is preferably used, and a polymer compound in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or via an arbitrary linking group is particularly preferably used. It is done. Further, in order to enable development with an alkaline developer or a neutral developer, it is preferable to introduce a carboxyl group, a sulfonic acid group, a quaternary ammonium group, or the like linked to the main chain via an arbitrary linking group. However, a polymer compound having a sulfonic acid group can be preferably used because of its high developability. The sulfonic acid group may form a salt (for example, sodium salt, potassium salt, lithium salt, ammonium salt, etc.). These linking groups are not particularly limited, and include any group, atom, or a combination thereof. The phenyl group and sulfonic acid group substituted with a vinyl group may be independently bonded to the main chain, or the phenyl group and sulfonic acid group substituted with a vinyl group share part or all of the linking group. You may combine in the form to do.

  In the phenyl group substituted by the vinyl group, the phenyl group may be substituted, and the vinyl group is a halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group. , An aryl group, an alkoxy group, an aryloxy group and the like may be substituted.

  In the present invention, the polymer compound in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or through an arbitrary linking group has a group having a group represented by the following general formula 2 in the side chain in detail. preferable.

In the formula, R ₅ , R ₆ and R ₇ may be the same or different and are each a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, or an alkyl group. A group selected from aryl group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group The alkyl group and aryl group constituting these groups are a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkenyl group, a hydroxy group, an alkoxy group. Group, aryloxy group, alkylsulfanyl group, ant It may be substituted with a sulfanyl group, an alkylamino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, or the like. Among these groups, those in which R ₅ and R ₆ are hydrogen atoms and R ₇ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (for example, a methyl group, an ethyl group, etc.) are particularly preferable.

In the formula, R ₈ is hydrogen atom, halogen atom, carboxyl group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino. And a group selected from a group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, and an arylsulfonyl group. The alkyl group and aryl group constituting these groups are halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkenyl group, alkynyl group, hydroxy group. , Alkoxy groups, aryloxy groups, alkylsulfanyl groups, arylsulfanyl groups, alkylamino groups, arylamino groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, alkylsulfonyl groups, arylsulfonyl groups, etc. good.

In the formula, L ₁ represents an atom selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom, or a polyvalent linking group consisting of an atom group selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. Represent. Specific examples include groups composed of the structural units exemplified below and the heterocyclic groups shown below. These groups may be used alone or in any combination of two or more.

The linking group L ₁ preferably includes a heterocyclic ring. Examples of the heterocyclic ring constituting L ₁ include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thia Triazole ring, indole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline And a nitrogen-containing heterocycle such as a ring and a quinoxaline ring, a furan ring, a thiophene ring, and the like. These heterocycles may have a substituent.

  When the polyvalent linking group described above has a substituent, examples of the substituent include a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkenyl group, and an alkynyl group. Group, hydroxy group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, etc. It is done.

In the formula, m ₁ represents an integer of 0 to 4, p ₁ represents an integer of 0 or 1, and q ₁ represents an integer of ₁ to 4.

  The polymer compound having a polymerizable double bond group may be a polymer composed of a repeating unit having a phenyl group in which a vinyl group is substituted on the side chain described above, and a repeating unit having a sulfonic acid group, Or the polymer which introduce | transduced another repeating unit may be sufficient as long as the effect of this invention is not prevented. Further, it may be a copolymer with another monomer, and such a monomer may be used alone or two or more of them may be used.

  In addition, a polymer compound having a polymerizable double bond group can introduce an arbitrary substituent to the end of the polymer main chain by using a chain transfer agent. Specifically, linear alkane thiols, particularly linear alkane thiols substituted with silicon atoms bonded to alkoxy groups or halogen atoms, are preferably used because they can be used at the time of polymerization as a chain transfer agent. Can do. Examples of such chain transfer agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrichlorosilane, 3-mercaptopropyldichloromethylsilane, 4 -Mercaptobutyltrimethoxysilane, 4-mercaptobutyldimethoxymethylsilane, 4-mercaptobutyltriethoxysilane, 4-mercaptobutyltrichlorosilane, 4-mercaptobutyldichloromethylsilane, and the like. May be bonded via an oxygen atom by hydrolytic condensation to form a siloxane bond.

  Preferred examples of the polymer compound having a polymerizable double bond group in the present invention are shown below, but the present invention is not limited to these examples. The numbers in the exemplified structural formulas represent the mass% of each repeating unit in the copolymer total composition of 100 mass%.

  The weight average molecular weight of the polymer compound having a polymerizable double bond group is preferably in the range of 1,000 to 1,000,000, and more preferably in the range of 50,000 to 600,000. In the present invention, the polymer compound having a polymerizable double bond group may be used alone or in combination of two or more.

  Next, the low molecular weight compound having a polymerizable double bond group used in the present invention will be described. The low molecular compound having a polymerizable double bond group in this case can be preferably used as long as it is a compound that undergoes polymerization by radicals generated by the photodecomposition of the photopolymerizable initiator. Furthermore, when a compound having two or more polymerizable double bond groups in the molecule is used, a crosslinked product is formed as a result of polymerization by radicals. Therefore, a negative photosensitive lithographic printing plate material is used. When constituted, it forms a cross-linked hard image part film, so that it can be used very preferably to give a printing plate excellent in printing durability and ink transferability. Examples of compounds having a polymerizable double bond group that can be used for such purposes include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tetraethylene glycol diacrylate. Polyfunctional acrylic monomers such as trisacryloyloxyethyl isocyanurate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc., or acryloyl group, methacryloyl group Polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, etc. are also used in the same way as various oligomers introduced with That.

  The photocurable photosensitive layer preferably contains a compound that sensitizes the photopolymerization initiator described above. As compounds that increase the sensitivity in the wavelength region of 400 to 430 nm, cyanine dyes, coumarin compounds described in JP-A-7-271284, JP-A-8-29973, etc., JP-A-9-230913, Carbazole compounds described in JP-A No. 2001-42524 and the like, carbomerocyanine dyes described in JP-A-8-262715, JP-A-8-272096, JP-A-9-328505, and the like, JP-A-4-194857, JP-A-6-295061, JP-A-7-84863, JP-A-8-220755, JP-A-9-80750, JP-A-9-236913, etc. Aminobenzylidene ketone dyes, JP-A-4-184344, JP-A-6-301208, The pyromethine dyes described in Kaihei 7-225474, JP-A-7-5585, JP-A-7-281434, JP-A-8-6245, etc., and JP-A-9-80751 Styryl dyes or (thio) pyrylium compounds. Of these, cyanine dyes, coumarin compounds or (thio) pyrylium compounds are preferred.

  As other elements constituting the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate material of the present invention, various colorants are preferably added for the purpose of improving visibility. The colorant is preferably an organic pigment having an absorption maximum at 400 to 700 nm. As such an organic pigment, conventionally known ones can be used, and commercially available organic pigments and color indexes (CI) can be used. Handbook, "Latest Pigment Handbook" (edited by the Japan Pigment Technology Association, published in 1977), "Latest Pigment Applied Technology" (published by CMC, 1986), "Printing Ink Technology" published by CMC, published in 1984) Is available.

  Examples of the organic pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent 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 and natural pigments can be used. Among these organic pigments, phthalocyanine pigments and dioxazine pigments are preferable.

  Preferred organic pigments are C.I. described in Color Index (Published by The Society of Dies and Colorists, Third Edition). I. These are listed below by Number, but are not limited thereto. Pigment Blue 15, 15: 3, 15: 4, 15: 6 (phthalocyanine pigment), Pigment Violet 23, 37 (dioxazine pigment), Pigment Violet 19 (quinacridone pigment), Pigment Blue 60 (slen pigment), Pigment Violet 1, 3 (basic dye lake pigment), Pigment Violet 29 (perylene pigment), and the like. Two or more of these pigments may be used simultaneously for the purpose of adjusting the color tone.

  When using a color pigment, it is preferable that it is contained in the range of 0.1-30 mass parts with respect to 100 mass parts of compounds which have a polymerizable double bond.

  The photopolymerizable photosensitive layer of the photosensitive lithographic printing plate of the present invention preferably contains a silane coupling agent. Although the photopolymerizable photosensitive layer contains a silane coupling agent, excellent printing durability can be obtained. However, in the photosensitive lithographic printing plate material having the hydrophilic layer of the present invention, anti-stain resistance and halftone resistance are observed. In particular, the printing durability is improved without deteriorating the properties and the ink detachment properties, which is particularly preferable.

  The silane coupling agent is not particularly limited as long as the purpose is achieved, and any silane coupling agent can be used. For example, epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxy Silane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane , Vinyltris (3-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimeth Sisilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -amino Propylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane 3-isocyanatopropyltriethoxysilane and the like. Among them, epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltri Particularly preferred are trialkoxysilanes such as ethoxysilane. In addition, a silane coupling agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the silane coupling agent contained in the photopolymerizable photosensitive layer is preferably in the range of 0.1 to 20% by mass with respect to the compound having a polymerizable double bond group contained in the photopolymerizable photosensitive layer.

  A polymerization inhibitor can be added to the photopolymerizable photosensitive layer of the present invention in order to prevent a curing reaction in the dark due to thermal polymerization for long-term storage. With such a polymerization inhibitor, it is possible to prolong the lifetime in which the sensitivity can be maintained (pot life) in the coating liquid state used when the photopolymerizable photosensitive layer is applied. Polymerization inhibitors preferably used for such purposes include hydroquinones, catechols, naphthols, cresols and other compounds having various phenolic hydroxyl groups, quinone compounds, 2,2,6,6-tetramethylpiperidine- N-oxyls, N-nitrosophenylhydroxylamine salts and the like are preferably used. In this case, the polymerization inhibitor is preferably used in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total solid content of the photopolymerizable photosensitive layer.

  Furthermore, in extending the lifetime of the sensitivity maintenance possible state (pot life) in the coating liquid state, the coating liquid uses at least one of the above-described photopolymerization initiator and a low molecular compound having a polymerizable double bond group as an underwater emulsion. An aqueous dispersion containing the same is preferable, and in particular, the coating liquid contains an aqueous emulsion of a photopolymerization initiator and an aqueous emulsion of a low molecular weight compound having a polymerizable double bond group. More preferably.

  When preparing emulsions in water of low molecular weight compounds having a photopolymerization initiator or a polymerizable double bond group, these compounds are exposed to a certain high temperature by emulsifying and dispersing them in water in the presence of an anionic surfactant. In addition, it is possible to obtain an underwater emulsion that can stably maintain an emulsified and dispersed state. Examples of such anionic surfactants include higher fatty acid salts such as sodium laurate, sodium stearate, and sodium oleate, alkyl sulfates such as sodium dialkylsulfosuccinate, sodium lauryl sulfate, and sodium stearyl sulfate, and octyl alcohol sulfate. Higher alcohol sulfates such as sodium, sodium lauryl alcohol sulfate, ammonium lauryl alcohol sulfate, aliphatic alcohol sulfates such as sodium acetyl alcohol sulfate, alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate, butyl naphthalene sulfone Alkyl naphthalene sulfonates such as sodium acid and sodium isopropyl naphthalene sulfonate Alkyl diphenyl ether disulfonates such as sodium rudiphenyl ether disulfonate, alkyl phosphate esters such as sodium lauryl phosphate and sodium stearyl phosphate, polyethylene oxide adducts of sodium lauryl ether sulfate, polyethylene oxide adducts of ammonium lauryl ether sulfate, trilauryl ether trisulfate Polyethylene oxide adducts of alkyl ether sulfates such as polyethylene oxide adduct of ethanolamine, polyethylene oxide adducts of alkyl phenyl ether sulfates such as polyethylene oxide adduct of sodium nonylphenyl ether sulfate, polyethylene of sodium lauryl ether phosphate Polyethylene oxide of alkyl ether phosphates such as oxide adducts De adducts, and polyethylene oxide adducts of alkyl phenyl ether phosphate salts of polyethylene oxide adducts of nonyl phenyl ether sodium phosphate and the like. Of these, sodium dialkylsulfosuccinate, alkylnaphthalene sulfonates and polyethylene oxide adducts of alkyl ether sulfates are particularly preferred because they form the most stable emulsions in water.

  Further, by adding the above-described polymer compound having a polymerizable double bond group and a sulfonate group, the emulsion dispersion stability is further improved. The polymer compound may be added at the time of emulsification dispersion of the photopolymerization initiator or the compound having a polymerizable double bond group, or may be added after the emulsification dispersion. Since the dispersed particle diameter of the product in water is remarkably reduced and dispersed in the form of extremely fine droplets and fine particles, problems such as sedimentation or levitation over time can be suppressed, which is more preferable. Furthermore, it is also possible to preferably perform a part of the polymer compound at the time of dispersion to prepare an underwater emulsion, and further add the polymer compound after a stable emulsion is prepared.

  In order to emulsify and disperse a low-molecular compound having a photopolymerization initiator or a polymerizable double bond group in water, a solution is prepared using an organic solvent capable of dissolving or dispersing each compound and mixed with water. A method of emulsifying and dispersing the aforesaid anionic surfactant or a polymer compound having a polymerizable double bond group and a sulfonate group is preferred. However, when the low molecular weight compound having a polymerizable double bond group is a liquid and the photopolymerization initiator is dissolved in the liquid and the mixture of both is liquid, the mixture of the two is used without using an organic solvent. Can be emulsified and dispersed in water. It is possible to prepare a photopolymerization initiator and a low molecular weight compound having a polymerizable double bond group in advance to prepare an emulsion in water in which both are mixed. good. Regarding the method of emulsifying and dispersing, any dispersing machine such as a rotary dispersing machine, a media mill, an ultrasonic dispersing machine or a kneading machine can be used, and a commercially available apparatus such as a homomixer, a homogenizer, or a sand grinder. Can be preferably used.

  The organic solvent that can be used for emulsification dispersion means an organic solvent that is liquid at room temperature and can dissolve or disperse a low-molecular compound having a photopolymerization initiator or a polymerizable double bond group. Examples of organic solvents that can be used in the present invention include volatile organic solvents and non-volatile organic solvents. When a volatile organic solvent is used, it is preferable to remove the volatile organic solvent from the produced emulsion in water by heating or leaving it. In the case of using a non-volatile organic solvent, the non-volatile organic solvent exhibits a flash point higher than 50 ° C., and the countermeasure as a dangerous substance may be reduced in normal handling, which is preferable.

  Examples of the solvent that can be preferably used in the present invention as the volatile organic solvent include lower alkanol acetates such as ethyl acetate, propyl acetate, and butyl acetate, ethylene glycol monomethyl ether acetate, and ethylene glycol monoethyl ether acetate. Ethylene glycol acetates such as methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, hydrocarbons such as hexane, cyclohexane and heptane, aromatics such as benzene, toluene and xylene, etc. Of these, ethyl acetate is most preferably used for various reasons described later.

  Nonvolatile organic solvents that can be used in the present invention include phosphoric acid esters, phthalic acid esters, acrylic acid esters, methacrylic acid esters and other carboxylic acid esters, fatty acid amides, alkylated biphenyls, alkylated terphenyls, alkylated naphthalenes, Examples include diarylethane, chlorinated paraffin, alcohol solvent, phenol solvent, ether solvent, monoolefin solvent, epoxy solvent and the like. Specific examples include tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, tricyclohexyl phosphate, dibutyl phthalate, dioctyl phthalate, dilaurate phthalate, dicyclohexyl phthalate, butyl olefinate, diethylene glycol benzoate, dioctyl sebacate, Dibutyl sebacate, dioctyl adipate, trioctyl trimellitate, acetyl triethyl citrate, octyl maleate, dibutyl maleate, isoamylbiphenyl, chlorinated paraffin, diisopropylnaphthalene, 1,1'-ditolylethane, monoisopropylbiphenyl, diisopropylbiphenyl, 2,4-ditertiaryamylphenol, N, N-dibutyl-2-butoxy-5-tertiaryoctylaniline, hydroxy Ikikosan ethylhexyl esters, high boiling point solvent such as polyethylene glycol.

  In the present invention, the organic solvent used for emulsifying and dispersing the low molecular weight compound having a photopolymerization initiator or a polymerizable double bond group is more preferably a volatile organic solvent. In this case, the emulsion in water can be most stably produced, and it is preferable because the emulsified dispersion state is kept stable even when exposed to a temperature higher than room temperature. As the volatile organic solvent, ethyl acetate is particularly preferable. Since ethyl acetate is highly volatile, it can be easily removed from the emulsion in water simply by placing it under heating or reduced pressure. The emulsion in water after the distillation of ethyl acetate is in a solid dispersion state, such as ethyl acetate. This is extremely preferable because it forms a coating solution that is more stable than a state containing a solvent.

  Next, a production method for producing an emulsion in water in which a photopolymerization initiator or a compound having a polymerizable double bond group is dispersed will be described more specifically.

  Using the organic solvent such as ethyl acetate described above, a solution in which a photopolymerization initiator or a low molecular compound having a polymerizable double bond group is dissolved or dispersed is prepared. A known stirring device capable of high-speed shearing such as a homomixer or a homogenizer when added to water containing an anionic surfactant or a polymer compound having a polymerizable double bond group and a sulfonate group An emulsified solution in water can be prepared by emulsifying and dispersing the composition. The organic solvent may contain other water-insoluble compounds contained in the coating solution for coating the photopolymerizable photosensitive layer of the present invention, and the water used as the dispersion medium may be contained in the coating solution. Other water soluble compounds may be added. Moreover, the emulsification dispersion method can be carried out in a batch manner, or can be carried out continuously in a state of flowing through the piping system in a continuous manner, and in that case, the emulsification dispersion is carried out in a temperature range of 0 to 70 ° C. Is preferred.

  Examples of the support used in the photosensitive lithographic printing plate material of the present invention include an aluminum support, various plastic films, and paper laminated with various plastics. Among them, various plastic films that are flexible and are less deformed by tension are preferably used. Preferred examples of the plastic film support include polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, and cellulose nitrate. In particular, polyethylene terephthalate and polyethylene naphthalate are preferably used. Further, before the hydrophilic layer is provided, it is preferable that the surface of the film support is subjected to a hydrophilic treatment. Examples of such a hydrophilic treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment. It is done. As a further hydrophilic treatment, an undercoat layer may be provided on the support in order to enhance adhesion with the hydrophilic layer provided on the support.

  When an aluminum plate is used as the support, an aluminum plate that is roughened and has an anodized film is preferably used. Furthermore, an aluminum plate whose surface is silicate-treated can also be preferably used. Or the aluminum plate which formed said hydrophilic layer in the surface further can also be used.

  The photocurable photosensitive layer is formed on the hydrophilic layer provided on the support. With respect to the dry solid content coating amount of the photocurable photosensitive layer itself, the dry mass is preferably 0.3 to 10 g per square meter, and more preferably in the range of 0.5 to 3 g, and a fine line is exhibited. This is extremely preferable in order to ensure the printing durability of images and fine dot images and at the same time to greatly improve the ink transportability. Arbitrary additives may be added to the coating solution used for coating the photopolymerizable photosensitive layer in order to improve various properties as a photosensitive lithographic printing plate material.

  In the photosensitive lithographic printing plate material of the present invention, it is also preferable to further provide a protective layer on the above-described photocurable photosensitive layer. The protective layer prevents the entry of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that inhibit the image formation reaction caused by exposure in the photocurable photosensitive layer into the photocurable photosensitive layer. It has a preferable effect of further improving the exposure sensitivity. Furthermore, the effect which prevents the photocurable photosensitive layer surface from a damage | wound is also anticipated. Therefore, the properties desired for such a protective layer are low permeability of low molecular weight compounds such as oxygen and excellent mechanical strength, and further, transmission of light used for exposure is not substantially inhibited. It is desirable that it has excellent adhesiveness and can be easily removed in the development step after exposure. In the photosensitive lithographic printing plate material of the present invention, it is possible to simultaneously remove the unexposed portion of the protective layer and the photocurable photosensitive layer in the course of water development. The feature is that it is not necessary. Furthermore, when the polymer contained in the photocurable photosensitive layer as described above is water-soluble, it absorbs moisture in the atmosphere and causes blocking, or causes a problem such as sensitivity change during storage. However, it is possible to solve such problems of blocking and sensitivity change by providing a protective layer on the photocurable photosensitive layer. In addition, in particular, when performing scanning exposure using a semiconductor laser or the like, a photocurable photosensitive layer having particularly high sensitivity is required. In such a case, since the sensitivity is further increased by providing a protective layer, it can be particularly preferably applied.

  Such a device relating to the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic are used. Water-soluble polymers such as acids are known, but among these, the use of polyvinyl alcohol as the main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether, and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. There is a preferred range for the coating amount of dry solids when applying such a protective layer, and it is preferable to form a dry solids coating amount in the range of 0.1 to 10 g per square meter on the photosensitive layer. Furthermore, the range of 0.2-2g is preferable. The protective layer is coated and dried on the photocurable photosensitive layer using various known coating methods.

  When applying a hydrophilic layer, a photocurable photosensitive layer, a protective layer, etc. in the photosensitive lithographic printing plate material of the present invention, a coating liquid of a composition comprising the above-described elements is applied on a support and dried. Is produced. Various known methods can be used as the coating method, and examples thereof include bar coater coating, curtain coating, slide hopper coating, blade coating, air knife coating, roll coating, spin coating, and dip coating. .

As a light source used for exposure for forming an image pattern on the photosensitive lithographic printing plate material of the present invention, a carbon arc, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a low pressure mercury lamp, a deep UV lamp, a xenon lamp, a metal halide lamp, a tungsten lamp, Although a halogen lamp, excimer UV lamp, LED lamp, various fluorescent lamps (white fluorescent lamp, black light, chemical light, etc.) can be used, scanning exposure with a laser is very preferable in terms of plate making efficiency. Examples of the laser light source include a blue-violet semiconductor laser (violet laser), an argon laser, a helium / neon laser, a red LED, a near infrared laser, and an infrared laser. Among them, GaN having a wavelength region of 390 to 430 nm is preferably used from the viewpoint of productivity and image definition. The scanning method may be any of an internal drum system, an external drum system, a planar scanning system, etc., but an internal drum system is preferred. Further, the laser intensity at the plate surface is preferably set to 1~600μJ / cm ^2, particularly preferably in the 30~400μJ / cm ^2.

  The developer used in the development processing of the photosensitive lithographic printing plate material of the present invention may contain an activator or an alkali agent as necessary for the purpose of improving the image quality and shortening the development time. When the compound having a polymerizable double bond has an acidic group such as a carboxyl group or a sulfo group, and the acidic group is in the form of a metal salt or an amine salt in the photosensitive layer, it will be described later. It is possible to develop with a developer substantially not containing an alkaline agent, that is, with a neutral developer having a pH of less than 9. In particular, when the compound having a polymerizable double bond has a neutralized salt of a sulfo group, good developability can be obtained and elution with pure water is possible. In the case where sufficient solubility cannot be obtained even with the sulfo group neutralized salt, an activator can be added to the neutral developer for the purpose of improving developability. Nonionic properties such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters, alkylbenzene sulfonates, alkyl naphthalene sulfonic acids Anionic surfactants such as salts, alkyl sulfates, alkyl sulfonates, sulfosuccinate esters, amphoteric surfactants such as alkyl betaines, amino acids, isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, Examples include water-soluble organic solvents such as diacetone alcohol.

  On the other hand, when the compound having a polymerizable double bond has an acid group that is not neutralized such as a carboxyl group or a sulfo group, the developer preferably contains an alkali agent. Alkaline agents include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, sodium metasilicate, potassium metasilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, diphosphoric acid Inorganic alkali salts such as sodium, sodium triphosphate, dibasic ammonium phosphate, tribasic ammonium phosphate, sodium borate, potassium borate, ammonium borate, or monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine , Diisopropylamine, monobutylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, etc. Is, they were added, can be used as an alkaline developing solution by adjusting to pH9 above. In addition, it is preferable to add the activator or the like used as the neutral developer to the alkali developer to improve the developability.

  The development is usually carried out by a known development method such as immersion development, spray development, brush development, ultrasonic development, etc., preferably at a temperature of about 10 to 60 ° C., more preferably about 15 to 45 ° C. for 5 seconds to It takes about 10 minutes. At that time, the protective layer provided as necessary on the photosensitive layer may be removed in advance with water or the like, or may be removed during development.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples. In addition, unless otherwise indicated, the number of parts and percentage in an Example are mass references | standards.

<Preparation of modified gelatin 1>
100 g of 5% aqueous solution of alkali-processed gelatin made from beef bone ossein (jelly strength 210 g) and glycidyl methacrylate 0.15 g were mixed to adjust the pH to 6.5, and then heated at 80 ° C. for 120 minutes to modify Gelatin 1 was obtained.

<Preparation of modified gelatin 2>
Modified gelatin 2 was obtained in the same manner except that the amount of glycidyl methacrylate mixed was changed from 0.15 g to 0.5 g in the production of modified gelatin 1.

<Preparation of modified gelatin 3>
Modified gelatin 3 was obtained in the same manner as modified gelatin 1 except that glycidyl methacrylate was used in place of modified gelatin 1 except that glycidyl methacrylate was used.

Example 1
A hydrophilic layer coating solution 1 having the following composition was applied on a polyethylene terephthalate film having a thickness of about 200 μm by a slide hopper coating method. At that time, the moisture application amount was set in advance to be 35 g / m ² . Immediately after coating, the coating film was gelled with cold air of 1 to 5 ° C., and then dried using a dry air set at 50 ° C. After drying, the support for lithographic printing plate was completed by putting it in a thermo-hygrostat adjusted to 40 ° C. and 40% RH and heating for 7 days.

<Hydrophilic layer coating solution 1>
Modified gelatin 1 (as solid content) 1.2 parts Inorganic filler 1: Titanium dioxide 4.0 parts (TISR1, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle diameter≈0.3 μm, relative refractive index≈2.04)
Inorganic filler 2: 1.6 parts of barium sulfate (B35, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size≈0.3 μm, relative refractive index≈1.23)
Inorganic filler 3: 0.4 parts of aluminum hydroxide (H42, manufactured by Showa Denko KK, average primary particle size ≈ 1.0 μm, relative refractive index ≈ 1.24)
Dispersant (acrylic acid copolymerized metal salt, 10% solution) 1.0 part Surfactant (POE nonylphenyl ether sulfate, 10% solution) 0.4 part Hardener (divinylsulfone, 5% solution) The total amount was 35 parts with 0 parts water.

  Regarding the particle size distribution and distribution frequency of the inorganic filler contained in the hydrophilic layer coating liquid 1, the inorganic fillers 2 and 3 contained in the hydrophilic layer coating liquid 1 are not added, but in the hydrophilic layer coating liquid. In addition, an inorganic filler 1 alone is prepared, and a coating liquid in which the inorganic fillers 2 and 3 are present alone in the hydrophilic layer coating liquid is prepared in the same manner. The particle size distribution and distribution frequency of the filler were measured using a laser diffraction / scattering type particle size distribution measuring device (LA920 manufactured by HORIBA Co., Ltd.), and the particle size distribution of each obtained single dispersion was multiplied by the addition ratio as a coefficient. The particle size distribution and distribution frequency of the hydrophilic layer coating solution 1 were calculated. As a result, the distribution frequency fx of the inorganic filler existing in the range of 0.2 μm or more and less than 0.6 μm is 64.8%, and the distribution frequency fy of the inorganic filler existing in the range of 0.6 μm or more and less than 1.5 μm is 30.1. %, Fx / fy ratio was 2.15 or more.

<Preparation of photosensitive aqueous emulsion>
6 parts of trimethylolpropane triacrylate as a compound having a polymerizable double bond group, 2 parts of an organic boron salt represented by BC-7 as a photopolymerization initiator, 1.5 parts of a trihaloalkyl-substituted compound represented by T-8, A solution A was prepared by weighing 0.05 part of a sensitizer having the following structure and 0.08 part of 3-acryloxypropyltrimethoxysilane and adding 200 parts of ethyl acetate to dissolve.

  Meanwhile, take 300 parts of ion-exchanged water, add 20 parts of SP-2 as a water-soluble polymer having a sulfonate group, and add 5 parts of Perex OTP (sodium dialkylsulfosuccinate: manufactured by Kao Corporation) as an anionic surfactant. Then, solution B was prepared.

  The underwater emulsion is prepared using a Mizuho Kogyo Co., Ltd. tabletop vacuum emulsifier PVQ-1D, which is equipped with a homomixer in an airtight container and capable of distilling the solvent while heating under reduced pressure. Went. The rotation speed of the homomixer was set to 5000 rpm. The solution A and the solution B prepared above were introduced into a vacuum emulsifier, and emulsified and dispersed by high-speed stirring with a homomixer for 20 minutes at room temperature. Thereafter, 0.2 parts of Pigment Blue 15 as a colorant was added and stirred, and the inside of the vacuum emulsifier was depressurized using an aspirator. Ethyl was distilled off under reduced pressure. From the amount of ethyl acetate collected in the cooler, it was confirmed that all the ethyl acetate used was distilled off from the emulsion in water. Thus, a photosensitive aqueous emulsion was prepared, and this was used as a coating solution for providing a photocurable photosensitive layer.

  The photocurable photosensitive layer was formed by apply | coating and drying the coating liquid obtained above on the hydrophilic layer of the support body which has a hydrophilic layer. The photocurable photosensitive layer was applied using a wire bar so that the dry weight was 1.6 g per square meter. Drying was performed by heating for 10 minutes in an oven at 80 ° C.

  Further, the following protective layer was applied onto the photocurable photosensitive layer so that the dry mass was 1.5 g per square meter, dried for 10 minutes in a dryer at 75 ° C., and photosensitive lithographic printing of Example 1 A plate material was obtained.

<Protective layer prescription>
Polyvinyl alcohol PVA-102 (manufactured by Kuraray Co., Ltd.) 1 part by mass Ion-exchanged water 9 parts by mass

<Exposure / Development>
About the photosensitive lithographic printing plate material obtained above, a test chart image was exposed using a blue-violet semiconductor laser (output 50 mW) emitting light at 405 nm as an exposure light source and setting the plate surface exposure energy to 200 μJ / cm ² . Thereafter, the plate was immersed in ion exchange water at 25 ° C. for 15 seconds, and the surface having the photopolymerizable photosensitive layer / protective layer was rubbed and developed with cellulose sponge, and then dried to prepare a printing plate. Using this printing press plate, printing durability was evaluated by the following method.

<Print durability>
The printing machine uses an offset sheet-fed press Heidelberg QM46, the printing ink is New Champion F gloss ink H manufactured by DIC Corporation, and the humidifying liquid is 1. Astro Mark III manufactured by Nikken Chemical Laboratory. Printing was performed using a 5% diluent. In the plate finishing, a gauge film was used, and the standard 200 μm was set to 300 μm (+100 μm). As an evaluation, the printing paper surface at the start and the printing paper surface at the time of printing 10,000 sheets are compared, and the attenuation factor of the highlight halftone dot portion and the fine defect in the solid portion are 25 times magnifier. Careful observation and judgment were made using the following evaluation criteria. The results are shown in Table 1.
A: Almost no change is observed in the highlight part and the solid part.
○: Slight attenuation (within an attenuation rate of 10% or less) is observed in the highlight portion.
However, no defects are observed in the solid part.
Δ: A clear attenuation (attenuation rate of 10% or more) is observed in the highlight portion.
However, no defects are observed in the solid part.
X: The highlight part is attenuated by 50% or more.
Or abnormalities such as defects are observed in the solid portion.

(Example 2)
The photosensitive lithographic printing plate material of Example 2 was prepared in the same manner as in the preparation of the photosensitive lithographic printing plate material of Example 1, except that the modified gelatin 1 contained in the hydrophilic layer coating solution 1 was replaced with the modified gelatin 2. Got. The resulting photosensitive lithographic printing plate material was evaluated for printing durability in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
The photosensitive lithographic printing plate material of Example 3 was prepared in the same manner as in the preparation of the photosensitive lithographic printing plate material of Example 1, except that the modified gelatin 1 contained in the hydrophilic layer coating solution 1 was replaced with the modified gelatin 3. Got. The resulting photosensitive lithographic printing plate material was evaluated for printing durability in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In the production of the photosensitive lithographic printing plate material of Example 1, the modified gelatin 1 contained in the hydrophilic layer coating solution 1 is converted into unmodified gelatin (alkali-treated gelatin made from bovine bone ossein: jelly strength 210 g). A photosensitive lithographic printing plate material of Comparative Example 1 was obtained in the same manner except that it was replaced. The resulting photosensitive lithographic printing plate material was evaluated for printing durability in the same manner as in Example 1. The results are shown in Table 1.

  From the above results, it can be seen that the present invention can provide a photosensitive lithographic printing plate material which is suitable for chemicalless development containing substantially no alkali agent and has excellent printing durability.

Claims (1)

  A photosensitive lithographic printing plate material having at least a hydrophilic layer and a photocurable photosensitive layer in this order on a support, wherein the hydrophilic layer is a compound having a polymerizable double bond group and an epoxy group in one molecule. A photosensitive lithographic printing plate material characterized by containing modified gelatin.