JP2006103086A - Plastic support for lithographic printing plate material, lithographic printing plate material and printing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing plate material excellent in on-press developing properties and print durability and a printing method. <P>SOLUTION: In a plastic support for a lithographic printing plate material, an underdcoating layer including a styrene-diolefin based copolymer is provided at least on one side of the plastic support and the lithographic printing plate material and the printing method are dealt. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a planographic printing plate material (also simply referred to as a printing plate material) using a plastic as a support and a printing method using the same.

  In recent years, with the digitization of print data, computer-to-plate (CTP) recording image data directly on a printing plate has become widespread. Generally, the printing plate material used for CTP includes a type using an aluminum support similarly to a conventional PS plate and a flexible type in which various functional layers as a printing plate are provided on a film substrate.

  In recent years, in the commercial printing field, there has been a tendency to increase the variety of printing in small quantities, and there is an increasing demand for high-quality and low-cost printing plate materials in the market. As a conventional flexible type printing plate material, for example, a silver salt diffusion transfer type photosensitive layer provided on a film substrate (see, for example, Patent Document 1), or a hydrophilic layer on a film substrate. A layer formed by laminating one of the lipophilic layers as a surface layer and ablating the surface layer by laser exposure to form a printing plate (for example, see Patent Documents 2 to 7), or a film substrate A hydrophilic layer and a heat-meltable image forming layer are provided thereon, and the image forming layer is melt-fixed on the hydrophilic layer by heating the hydrophilic layer or the image forming layer in an image-like manner by laser exposure (for example, patent documents) 8).

  On the other hand, as an image forming method for printing, the printing plate after image data writing (image-like exposure) is directly printed with an offset printing machine from the viewpoint of environmental suitability and the like, and only the image forming layer of the non-image portion is used with dampening water. There is known a method of developing on a so-called printing machine that swells and dissolves and transfers and removes it on printing paper (waste paper) at the initial stage of printing (see Patent Documents 9 and 10). These on-press developable printing plate materials provide sharp dot shapes and high-definition images, and do not require a development process after exposure, and are excellent in environmental suitability.

However, since these printing plate materials use a plastic support as a support, if the adhesion between the hydrophilic layer and the support is poor, the initial ink setting property is deteriorated or the printing durability is not good. There was a problem that it was enough. In order to improve the adhesion between the support and the lowermost layer, examples of using a support whose surface is corona-treated are given (for example, see Patent Document 11), and a plasma-treated support is disclosed. (For example, refer to Patent Document 12.) However, even if these surface treatments are performed, when a plastic film support is used in a lithographic printing plate precursor, a practically sufficient support is obtained so that a large number of printed materials can be obtained. The adhesion between the body and the lowermost layer has not been achieved, and there is a strong demand for improvement.
JP-A-5-66564 Japanese translation of Japanese translation of PCT publication No. 8-507727 JP-A-6-186750 JP-A-6-199064 JP 7-314934 A JP-A-10-58636 Japanese Patent Laid-Open No. 10-244773 JP 2001-96710 A JP-A-9-123387 JP-A-9-123388 Japanese Patent Laid-Open No. 11-245529 JP 11-245530 A

  An object of the present invention is to provide a printing plate material and a printing method excellent in on-press developability and printing durability.

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

(Claim 1)
A plastic support for a lithographic printing plate material, comprising an undercoat layer containing a styrene-diolefin copolymer on at least one surface of the plastic support.

(Claim 2)
Two undercoat layers, an undercoat layer adjacent to the support contains a styrene-diolefin copolymer, and an undercoat upper layer is gelatin, a water-based polymer containing a polyvinyl alcohol unit, polyester, vinyl type The plastic support for a lithographic printing plate material according to claim 1, comprising at least one of polymers.

(Claim 3)
3. The plastic support for a lithographic printing plate material according to claim 1, wherein corona discharge, glow discharge, or plasma treatment is applied before applying the undercoat layer.

(Claim 4)
The hydrophilic layer containing the inorganic hydrophilic compound obtained by sol-gel conversion on the surface side provided with the undercoat layer of the plastic support for the lithographic printing plate material according to any one of claims 1 to 3 A lithographic printing plate material comprising:

(Claim 5)
The lithographic printing plate material according to claim 4, further comprising an image-forming functional layer containing heat-meltable fine particles or heat-fusible fine particles on the hydrophilic layer side.

(Claim 6)
The lithographic printing plate material according to claim 4 or 5, wherein the hydrophilic layer or the image forming functional layer contains a photothermal conversion material.

(Claim 7)
The lithographic printing plate material according to any one of claims 4 to 6, wherein the image forming functional layer is an on-press developable layer.

(Claim 8)
The lithographic printing plate material according to any one of claims 4 to 7, wherein the lithographic printing plate material is in the form of a roll.

(Claim 9)
An image is formed on the lithographic printing plate material according to any one of claims 4 to 8 using a thermal head or a thermal laser, and then development is performed with a fountain solution or a fountain solution and printing ink on the lithographic printing machine. A printing method characterized by performing and printing.

  According to the present invention, a printing plate material and a printing method excellent in on-press developability and printing durability can be provided.

The present invention will be described in more detail.
(Support)
As a constituent material of the plastic film support according to the present invention, a plastic film is preferable, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyamide, polycarbonate, polysulfone, polyphenylene oxide, cellulose esters and the like. Can be mentioned. Among these, polyester PET and PEN are preferable from the viewpoint of handling suitability for the printing plate material, and PET is particularly preferable.

  PET is composed of terephthalic acid and ethylene glycol, and PEN is composed of naphthalene dicarboxylic acid and ethylene glycol, which can be polymerized by combining them in the presence of a catalyst under suitable reaction conditions. At this time, you may mix an appropriate 1 type, or 2 or more types of 3rd component. The suitable third component may be any compound having a divalent ester-forming functional group. Examples of the dicarboxylic acid include the following.

  Isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethane dicarboxylic acid, cyclohexane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl thioether dicarboxylic acid, diphenyl Examples thereof include ketone dicarboxylic acid and phenylindane dicarboxylic acid.

  Examples of glycols include ethylene glycol, propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, bis (4-Hydroxyphenyl) sulfone, bisphenol full orange hydroxyethyl ether, diethylene glycol, neopentyl glycol, hydroquinone, cyclohexanediol and the like can be mentioned.

  The intrinsic viscosity of the PET resin and film according to the present invention is preferably 0.5 to 0.8. Moreover, you may mix and use what has a different intrinsic viscosity.

  The method for synthesizing PET according to the present invention is not particularly limited, and can be produced according to a conventionally known method for producing PET. For example, a direct esterification method in which a dicarboxylic acid component is directly esterified with a diol component. First, a dialkyl ester is used as a dicarboxylic acid component, this is transesterified with the diol component, and this is heated under reduced pressure. A transesterification method of polymerizing by removing excess diol component can be used. At this time, if necessary, a transesterification catalyst or a polymerization reaction catalyst can be used, or a heat-resistant stabilizer can be added. Examples of the heat stabilizer include phosphoric acid, phosphorous acid, and ester compounds thereof. In addition, anti-coloring agents, crystal nucleating agents, slipping agents, stabilizers, anti-blocking agents, UV absorbers, viscosity modifiers, clearing agents, antistatic agents, pH adjusters, dyes, pigments, etc. May be added.

  Next, the manufacturing method of the plastic support body for lithographic printing plate materials of this invention is demonstrated. A method of obtaining an unstretched sheet and a method of uniaxially stretching in the machine direction can be performed by a conventionally known method. For example, the raw material polyester is molded into pellets, dried with hot air or vacuum, melt-extruded, extruded into a sheet from a T-die, brought into close contact with a cooling drum by an electrostatic application method, etc., cooled and solidified, and unstretched Get a sheet. Next, the obtained unstretched sheet is heated in the range of polyester glass transition temperature (Tg) to Tg + 100 ° C. through a plurality of roll groups and / or a heating device such as an infrared heater, and longitudinally stretched. The draw ratio is usually in the range of 2.5 to 6 times.

  At this time, it is possible to make it difficult to wind the film by providing a temperature difference between the front and back surfaces of the support. Specifically, the temperature can be controlled by providing a heating means such as an infrared heater on one side during heating in the longitudinal stretching. The temperature difference during stretching is preferably 0 ° C to 40 ° C, more preferably 0 ° C to 20 ° C. When the temperature difference is larger than 40 ° C., the film cannot be uniformly stretched and the flatness of the film tends to deteriorate, which is not preferable.

  Next, the polyester film uniaxially stretched in the longitudinal direction obtained as described above is transversely stretched in a temperature range of Tg to Tg + 120 ° C., and then heat-set. The transverse draw ratio is usually 3 to 6 times, and the ratio between the longitudinal and transverse draw ratios is appropriately adjusted so as to have preferable characteristics by measuring the physical properties of the obtained biaxially stretched film. Next, heat setting is performed at a temperature higher than the final transverse stretching temperature and usually within 0.5 to 300 seconds within a temperature range of Tg + 180 ° C. or less. At this time, it is preferable to heat-set at two or more temperatures. Thus, a film heat-set at two or more temperatures has improved dimensional stability and is effective as a support for a printing plate material.

  In addition, the support for a printing plate material of the present invention is preferably subjected to a relaxation treatment in terms of dimensional stability. The relaxation treatment is preferably carried out in the transverse stretch tenter or after the tenter is taken out and wound up after the polyester film is heat-set during the stretch film-forming step. The relaxation treatment is preferably performed at a treatment temperature of 80 ° C to 200 ° C, more preferably a treatment temperature of 100 ° C to 180 ° C. In addition, the relaxation rate is preferably in the range of 0.1% to 10% in both the longitudinal direction and the width direction, and more preferably, the relaxation rate is 2 to 6%.

(Fine particles)
Moreover, it is preferable to add 0.01 ppm-10 micrometers microparticles | fine-particles to said support body 1 ppm-1000 ppm for a handleability improvement. Here, the fine particles may be either organic or inorganic. For example, as the inorganic substance, silica described in Swiss Patent No. 330,158, etc., glass powder described in French Patent No. 1,296,995, etc., British Patent No. 1,173,181, etc. Alkaline earth metals or carbonates such as cadmium and zinc described in the book can be used. Examples of organic substances include starch described in US Pat. No. 2,322,037 and the like, starch derivatives described in Belgian Patent 625,451 and British Patent 981,198, and the like. No. 44-3643, etc., polyvinyl alcohol described in Swiss Patent No. 330,158 etc., polymethacrylate, US Pat. No. 3,079,257, etc., polyacrylonitrile, US Patent Organic fine particles such as polycarbonates described in US Pat. No. 3,022,169 can be used. The shape of the fine particles may be either regular or irregular.

Support according to the present invention, from the viewpoint of imparting the handling aptitude to printing plate material of the present invention, it is preferable that the elastic modulus is ^{300kg / mm 2 ~800kg / mm 2} , more preferably 400 kg / mm ² it is a ~600kg / mm ^2. Here, the elastic modulus is obtained by using a tensile tester to obtain the slope of the stress with respect to the strain amount in a region where the strain indicated by the standard line of the sample conforming to JIS C2318 and the corresponding stress have a linear relationship. It is a thing. This is a value called Young's modulus, and in the present invention, the Young's modulus is defined as an elastic modulus.

  Furthermore, the support according to the present invention has an average film thickness from the viewpoint of improving handling suitability when the printing plate material is installed in a printing machine in order for the printing plate material of the present invention to exhibit the effects described in the present invention. Is in the range of 100 μm to 500 μm, and the thickness distribution is preferably 5% or less. Especially preferably, it is the range of 120 micrometers-300 micrometers, and thickness distribution is 2% or less. The thickness distribution of the support according to the present invention is a value obtained by dividing the difference between the maximum value and the minimum value of the thickness by the average thickness and expressed as a percentage. Here, the method for measuring the thickness distribution of the support is as follows. The support cut out into a square having a side of 60 cm is drawn in a grid pattern at intervals of 10 cm vertically and horizontally, the thickness of these 36 points is measured, and the average value and maximum value are measured. Find the value and minimum value.

  The plastic support of the present invention may be heat treated to reduce curling. As a heat treatment method, there are a method in which each constituent layer of the printing plate material is subjected to heat treatment after being wound in a roll form after coating and drying, or a method in which heat treatment is performed using a transport line during coating and drying. .

  As a method of heat treatment in roll form, as described in JP-A No. 51-16358, etc., a heat treatment for 0.1 to 1500 hours is carried out in a temperature range equal to or lower than the glass transition temperature after film formation of the polyester support. There is a way to do. In this case, from the viewpoint of preventing blocking between the films, embossing, bending the edge part, or partially thickening the film partly or over the entire edge or center part of the film. Is preferred. In order to prevent deformation due to the transfer of the winding core, it is preferable that the material and structure have a strength that does not cause bending even when the film is wound and can withstand the heat treatment temperature.

  On the other hand, as a method of performing heat treatment using a conveyance line, as described in JP-A-10-39448, etc., heat treatment is performed while conveying a zone having a temperature gradient from the glass transition temperature or higher to the glass transition temperature. By doing so, curling can be reduced. Longer time is preferable, but from the viewpoint of productivity and transportability, it is preferable to heat-treat while transporting at CS: 5 m / min to 50 m / min. The transport tension is not particularly specified, but a tension of 5 kg / m to 60 kg / m is preferable. If the heat treatment is performed with CS or conveying tension other than the above, wrinkles are generated or the surface property of the support is deteriorated, which is not preferable. Examples of the heat treatment in line conveyance include a method of conveying a film while holding it in a flat state, a conveyance method using pins and clips, an air conveyance method, a roll conveyance method, and the like. Preferred are air conveyance and roll conveyance methods, and more preferred is roll conveyance.

  As the support according to the present invention, a plastic film support is used, but a plastic film and a metal plate (for example, iron, stainless steel, aluminum, etc.) or a material such as paper coated with polyethylene (also referred to as a composite substrate). A composite support appropriately bonded can also be used. These composite substrates may be bonded together before forming the coating layer, may be bonded after forming the coating layer, or may be bonded immediately before being attached to the printing press.

  In the present invention, an undercoat layer using a styrene-diolefin copolymer is provided on at least one surface of a plastic support, and a layer using a styrene-diolefin copolymer is used as the undercoat layer. In the case of using an undercoat upper layer, at least one of gelatin, an aqueous polymer containing a polyvinyl alcohol unit, polyester, and a vinyl-based polymer is used. Before applying the undercoat layer, corona discharge, glow discharge or plasma treatment is performed. It is preferable to apply any one of or in combination. As a result, the adhesion to the support or the adhesion to the hydrophilic layer is improved, and the on-press developability and printing durability are improved.

Styrene-diolefin A styrene-diolefin copolymer of the present invention is preferably a diolefin rubber-like substance. The diolefin monomer refers to a monomer having two double bonds in one molecule, and may be an aliphatic unsaturated hydrocarbon or a cyclic structure.

  Specifically, butadiene, isoprene, chloroprene and conjugated dienes such as 1,4-pentadiene, 1,4-hexadiene, 3-vinyl-1,5-hexadiene, 1,5-hexadiene, 3- Methyl-1,5-hexadiene, 3,4-dimethyl-1,5-hexadiene, 1,2-divinylcyclobutane, 1,6-heptadiene, 3,5-diethyl-1,5-heptadiene, 4-cyclohexyl-1 , 6-heptadiene, 3- (4-pentenyl) -1-cyclopentene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,9-octadecadiene, 1-cis-9-cis -1,2-octadecatriene, 1,10-undecadiene, 1,11-dodecadiene, 1,12-tridecadiene, 1,13-tetrade Njien, 1,14 penta decadiene, 1,15- hexa decadiene, 1,17- octadecadienoic, mention may be made of 1,21- docosadienoic like.

  Of these diolefin monomers, butadiene, isoprene and chloroprene which are conjugated dienes are particularly preferably used, and butadiene is particularly preferably used.

  Styrene, which is one monomer that forms a copolymer, refers to styrene and styrene derivatives, such as methyl styrene, dimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl. Styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene, chloro styrene, dichloro styrene, trichloro styrene, tetrachloro Styrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluoro Len, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, vinylbenzoic acid, vinylbenzoic acid methyl ester, divinylbenzene, 1,5-hexadiene-3-yne, hexatriene, etc. Can be mentioned.

  The content of the diolefin monomer in the copolymer of the present invention is preferably 10 to 60% by mass, particularly 15 to 40% by mass, based on the entire copolymer. It is preferable that styrenes are 70-40 mass% of the whole copolymer. Further, the third component monomer may be incorporated into the copolymer used in the present invention. As the third component, chlorine-containing monomers such as acrylate esters, metal acrylate esters, vinyl esters and vinyl chloride are preferable. A monomer having two or more vinyl groups, acryloyl, etc., such as a methacryloyl group or an allyl group in the molecule can be copolymerized.

  Examples of the polymerization method of the copolymer include an emulsion polymerization method, a solution polymerization method, a bulk polymerization method, a suspension polymerization method, a radiation polymerization method, and the like, and a latex-like method by emulsion polymerization is preferable. Moreover, when using a crosslinkable monomer, it is preferable that the gel fraction of latex is 50-95 mass%. Here, the gel means a state in which the copolymer component is three-dimensionally polymerized. When the copolymer having the composition as in the present invention is polymerized three-dimensionally, the solubility in the solvent changes depending on the degree of the three-dimensional polymerization. That is, it becomes difficult to dissolve as the degree of three-dimensional polymerization proceeds. Therefore, the degree of three-dimensional polymerization of the gel is judged from its solubility. Of course, since the solubility differs depending on the solvent used, the definition of the degree of three-dimensional polymerization of the gel differs depending on the solvent. In the present invention, the gel is a three-dimensionally copolymerized state. In addition, the degree of three-dimensional polymerization is such that it does not dissolve even when immersed in purified tetrahydrofuran at 20 ° C. for 48 hours.

  In the emulsion polymerization method, water is used as a dispersion medium, the monomer is 10 to 50% by mass with respect to water, the polymerization initiator is 0.05 to 5% by mass with respect to the monomer, and 0.1 to 20% by mass. And a polymerization agent at about 30 to 100 ° C., preferably 60 to 90 ° C. for 3 to 8 hours with stirring. The monomer concentration, initiator amount, reaction temperature, time, etc. can be varied widely and easily. As the dispersant, a water-soluble polymer is used, and any of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used. Various dispersion aids can be used to increase the dispersion stability of the latex during or after polymerization. Dispersing aids include anionic or nonionic active agents such as polyvinyl alcohol, hydroxy protective polymer colloids such as hydroxymethyl cellulose, sodium dodecylbenzene sulfonate, sodium laurate, polyoxyethylene fatty acid monoester, polyoxyethylene phenyl ether, etc. Can be used. If necessary, mercaptans that are molecular weight regulators may be added. The polymerization should be carried out in a sealed container and changed according to the method of adding each component to the polymerization system, the addition concentration, the temperature, pressure, and stirring conditions during the polymerization reaction. The diolefin monomer may be added with silicic acid, or may be recovered after completion of the reaction by adding an excess amount. The average particle size of the copolymer is particularly preferably 0.01 to 0.8 μm, and any copolymer having an average particle size of 0.005 to 2.0 μm can be preferably used.

  The hydrophobic polymer used for the undercoat layer is preferably an aqueous dispersion (latex), and if necessary, a crosslinking agent, a surfactant, a swelling agent, a matting agent, an antistatic agent and the like are preferably added to the aqueous dispersion. . Examples of the crosslinking agent include triazines described in U.S. Pat. Nos. 3,325,287, 3,288,775, 3,549,377, Belgian Patent 6,602,226 and the like. Compounds, U.S. Pat. Nos. 3,291,624, 3,232,764, French Patent 1,543,694 and British Patent 1,270,578 Compounds, epoxy compounds described in US Pat. No. 3,091,537, JP-B-49-26580, vinyl compounds described in US Pat. No. 3,642,486, etc., US patents There are aziridine compounds described in US Pat. No. 3,392,024, ethyleneimine compounds described in US Pat. No. 3,549,378, and methylol compounds. Of these compounds, dichlorotriazine derivatives are preferred.

  The undercoat layer of the present invention preferably contains a water-soluble polymer in order to improve applicability. Examples of water-soluble polymers include hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), ethylhydroxyethylcellulose (EHEC), and hydroxyethylcellulose (HMHEC) modified to have hydrophobicity. , Polyvinyl pyrrolidone (PVP), polyethylene oxide (PEO), xanthan, cationic hydroxyethyl cellulose (CATHEC), hydroxypropyl guar (HP guar), guar, polyvinyl alcohol (PVA), polyacrylamide, sodium alginate, and carbopol Registered trademark) acrylamide thickening composition.

  When a layer using a styrene-diolefin copolymer is used for the undercoat layer, the adhesion to the support is improved, but depending on the formulation of the hydrophilic layer, sufficient adhesion as a printing material cannot be obtained. There is a case. In that case, at least one of gelatin, an aqueous polymer containing a polyvinyl alcohol unit, polyester, and a vinyl-based polymer is used for the undercoat upper layer, or corona discharge or glow discharge treatment is performed before applying the undercoat layer. By applying, the adhesiveness with the hydrophilic layer can be improved, and the on-press developability and printing durability can be improved. Each material that can be used for the undercoat upper layer will be described below.

Polyester The polyester is a substantially linear polyester obtained by polycondensation reaction of a polybasic acid or its ester and a polyol or its ester. Further, when used in aqueous form, a polyester having a hydrophilic group, for example, a component having a sulfonate, a diethylene glycol component, a polyalkylene ether glycol component, a polyether dicarboxylic acid component or the like introduced as a copolymer component in the polyester is used. Say. As the component having a hydrophilic group, a dicarboxylic acid having a sulfonate (hereinafter, dicarboxylic acid is also referred to as a polybasic acid) is preferably used.

  Examples of the polybasic acid component of polyester include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, Pyromellitic acid, dimer acid, maleic acid, fumaric acid, itaconic acid, p-hydroxybenzoic acid, p- (β-hydroxyethoxy) benzoic acid and the like can be used. The dicarboxylic acid having a sulfonate is particularly preferably one having an alkali metal sulfonate group, such as 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, Alkali metal salts such as 4-sulfonaphthalene-2,7-dicarboxylic acid and 5- (4-sulfophenoxy) isophthalic acid can be mentioned, among which sodium 5-sulfoisophthalic acid is particularly preferable. The dicarboxylic acid having these sulfonates is preferably used in the range of 5 to 15 mol%, particularly in the range of 6 to 10 mol% with respect to the total dicarboxylic acid component from the viewpoint of water solubility and water resistance. As the aqueous polyester, those having terephthalic acid and isophthalic acid as main dicarboxylic acid components are preferred, and the ratio of terephthalic acid and isophthalic acid to be used is 30/70 to 70/30 in molar ratio. It is particularly preferred from the viewpoint of applicability to water and solubility in water. Moreover, it is preferable to contain 50-80 mol% of these terephthalic acid components and isophthalic acid components with respect to all the dicarboxylic acid components, and it is preferable to use alicyclic dicarboxylic acid as a copolymerization component. Examples of these alicyclic dicarboxylic acids include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, Mention may be made of cyclohexyldicarboxylic acid. Furthermore, dicarboxylic acids other than those described above can be used as copolymerization components in the aqueous polyester of the present invention using terephthalic acid and isophthalic acid as the main dicarboxylic acid components. Examples of these dicarboxylic acids include aromatic dicarboxylic acids and linear aliphatic dicarboxylic acids. The aromatic dicarboxylic acid is preferably used within a range of 30 mol% or less of the total dicarboxylic acid component. Examples of these aromatic dicarboxylic acid components include phthalic acid, 2,5-dimethylterephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and biphenyldicarboxylic acid. Further, the linear aliphatic dicarboxylic acid is preferably used within a range of 15 mol% or less of the total dicarboxylic acid component. Examples of these linear aliphatic dicarboxylic acid components include adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid.

  Examples of the polyol component include ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylylene glycol, and trimethylol. Propane, poly (ethylene oxide) glycol, poly (tetramethylene oxide) glycol can be used.

  As the glycol component of the aqueous polyester, it is preferable to use one having ethylene glycol of 50 mol% or more of the total glycol component.

  Polyesters can be synthesized using dicarboxylic acids or their esters and glycols or their esters as starting materials. Various methods can be used for the synthesis. For example, it can be obtained by a known polyester production method in which an initial condensate of dicarboxylic acid and glycol is formed by transesterification or direct esterification and melt polymerized. be able to. More specifically, for example, an ester exchange reaction between an ester of a dicarboxylic acid, for example, a dimethyl ester of a dicarboxylic acid, and a glycol is performed, and after distilling methanol, the pressure is gradually reduced and polycondensation is performed under a high vacuum. Method of performing, esterification reaction of dicarboxylic acid and glycol, distilling out the generated water, then gradually depressurizing, polycondensation under high vacuum, transesterification reaction between dicarboxylic acid ester and glycol And a method of performing polycondensation under high vacuum after adding an esterification reaction by adding dicarboxylic acid. Known transesterification catalysts and polycondensation catalysts can be used, such as manganese acetate, calcium acetate, and zinc acetate as transesterification catalysts, and antimony trioxide, germanium oxide, and dibutyltin as polycondensation catalysts. Oxides, titanium tetrabutoxide, and the like can be used. However, various conditions such as a polymerization method and a catalyst are not limited to the above examples.

Vinyl-based polymer As the vinyl-based polymer of the present invention, acrylic monomers such as alkyl acrylate and alkyl methacrylate (the alkyl group is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.); 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, etc. Hydroxyl group-containing monomer: acrylamide, methacrylamide, N-methyl methacrylamide, N-methyl acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, N-dimethylol Amide group-containing monomers such as clinamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, and N-phenylacrylamide; Amino group-containing monomers such as N, N-diethylaminoethyl acrylate and N, N-diethylaminoethyl methacrylate; Glycidyl acrylate And epoxy group-containing monomers such as glycidyl methacrylate; monomers containing carboxyl groups such as acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) or salts thereof. Examples of monomers other than acrylic monomers include epoxy group-containing monomers such as allyl glycidyl ether; sulfonic acid groups such as styrene sulfonic acid, vinyl sulfonic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) Or a monomer containing a salt thereof; a monomer containing a carboxyl group or a salt thereof such as crotonic acid, itaconic acid, maleic acid, fumaric acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.); maleic anhydride, Monomers containing acid anhydrides such as itaconic anhydride; vinyl isocyanate; allyl isocyanate; styrene; vinyl trisalkoxysilane; alkyl maleic acid monoester; alkyl fumaric acid monoester; acrylonitrile; methacrylonitrile; Monoester; vinylidene chloride; vinyl acetate; vinyl chloride and the like. As the vinyl monomer, it is preferable to use an epoxy group-containing monomer such as glycidyl acrylate or glycidyl methacrylate from the viewpoint of coating strength.

  It is environmentally preferable that the vinyl polymer in the present invention is in the form of a polymer latex. The polymer latex refers to a polymer component in which a water-insoluble hydrophobic polymer is dispersed as fine particles in water or a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion polymerized, the micelle dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. As for the polymer latex according to the present invention, “synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Kobunshi Publishing Co., Ltd. (1978))”, “application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara) Edited, published by Polymer Publishing Association (1993)), "chemistry of synthetic latex (written by Soichi Muroi, published by Polymer Publishing Society (1970))", and the like.

  The average particle diameter of the dispersed particles of the polymer latex is preferably in the range of 1 to 50,000 nm, more preferably about 5 to 1000 nm. Regarding the particle size distribution of the dispersed particles, those having a wide particle size distribution or monodispersed particle size distribution may be used.

  The vinyl polymer latex according to the present invention may be a so-called core / shell type polymer latex other than a normal polymer latex having a uniform structure. In this case, it may be preferable to change the glass transition temperature between the core and the shell.

  The minimum film-forming temperature (MFT) of the vinyl polymer latex according to the present invention is preferably −30 ° C. to 90 ° C., more preferably about 0 ° C. to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. )"It is described in.

Polymer having vinyl alcohol unit In the present invention, it is preferable that at least one layer contains an aqueous polymer containing a polyvinyl alcohol unit. By containing the polyvinyl alcohol unit, the adhesiveness with the hydrophilic layer and the backcoat layer is improved, and the on-press developability, registration deviation and printing durability are improved.

  The polymer having a vinyl alcohol unit used in the undercoat layer will be described.

  Examples of the polymer having a vinyl alcohol unit in the present invention include polyvinyl alcohol and derivatives thereof, such as ethylene copolymer polyvinyl alcohol, modified polyvinyl alcohol obtained by partial butyralization and dissolved in water.

  As the polyvinyl alcohol, a polymerization degree of 100 or more and a saponification degree of 60 or more are preferable, and as derivatives thereof, vinyl compounds such as ethylene and propylene, and acrylic acid esters as copolymerization components of vinyl acetate-based polymers before saponification. (For example, t-butyl acrylate, phenyl acrylate, 2-naphthyl acrylate, etc.), methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate, 2-hydroxypropyl methacrylate, phenyl methacrylate, cyclohexyl) Methacrylate, cresyl methacrylate, 4-chlorobenzyl methacrylate, ethylene glycol dimethacrylate, etc.), acrylamides (eg, acrylamide, methyl) Acrylamide, ethylacrylamide, propylacrylamide, butylacrylamide, tert-butylacrylamide, cyclohexylacrylamide, benzylacrylamide, hydroxymethylacrylamide, methoxyethylacrylamide, dimethylaminoethylacrylamide, phenylacrylamide, dimethylacrylamide, diethylacrylamide, β-cyanoethylacrylamide, di Acetone acrylamide, etc.), methacrylamides (eg methacrylamide, methyl methacrylamide, ethyl methacrylamide, propyl methacrylamide, butyl methacrylamide, tert-butyl methacrylamide, cyclohexyl methacrylamide, benzyl methacrylamide, hydroxymethyl methacrylamide Mido, methoxyethyl methacrylamide, dimethylaminoethyl methacrylamide, phenyl methacrylamide, dimethyl methacrylamide, diethyl methacrylamide, β-cyanoethyl methacrylamide, etc.), styrenes (eg, styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl) Styrene, isopropyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, vinyl benzoic acid methyl ester, etc.), divinyl benzene, acrylonitrile, methacrylonitrile, N-vinyl pyrrolidone, N-vinyl oxazolidone, vinylidene chloride And polymers having monomer units such as phenyl vinyl ketone. Among these, ethylene copolymerized polyvinyl alcohol is preferable.

  In this invention, the ratio of the polymer containing the polyvinyl alcohol unit contained in an undercoat layer is 1-50 mass% with respect to all the binders of an undercoat layer, Preferably it is 5-30 mass%. The effect of being less than 1% is small and not preferable. On the other hand, if it is 50% or more, the hydrophilicity becomes strong and the printing durability at high humidity deteriorates, which is not preferable.

  In the present invention, it is preferable to contain at least one of gelatin, an aqueous polymer containing polyvinyl alcohol units, polyester, and vinyl polymer. When two or more kinds are contained, a method of mixing two kinds of polymers and one kind Among these polymers, there is a method of polymerizing other polymers, that is, a so-called protective colloid type modification to contain two kinds of polymers.

  In the latter case, for example, a vinyl polymer is polymerized in gelatin and a vinyl polymer is polymerized in polyester.

  In the case of polymerizing a vinyl polymer in polyester, a vinyl monomer is dispersed and polymerized in an aqueous solution of a hydrophilic polyester copolymer. The dispersion is, for example, a hydrophilic polyester copolymer in hot water. It can be obtained by dissolving and dispersing a vinyl monomer in an aqueous solution of the obtained hydrophilic polyester copolymer, followed by emulsion polymerization or suspension polymerization. The polymerization is preferably performed by an emulsion polymerization method.

  As the vinyl monomer, the above-mentioned vinyl monomers can be used. Examples of the polymerization initiator that can be used include ammonium persulfate, potassium persulfate, sodium persulfate, and benzoyl peroxide. Of these, ammonium persulfate is preferred. The polymerization can be carried out without using a surfactant, but a surfactant can also be used as an emulsifier for the purpose of improving the polymerization stability. In this case, both general nonionic and anionic surfactants can be used.

  The ratio of the vinyl monomer to the polyester is preferably in the range of 50/50 to 3/97, and in the range of 30/70 to 5/95, even in the mixture of the modified monomer of the vinyl monomer and the mixture of the vinyl monomer and the polyester. More preferably, it is in the range of 20/80 to 10/90.

Corona discharge, glow discharge, plasma treatment In the present invention, it is preferred that the support is subjected to corona discharge treatment, glow discharge treatment, plasma treatment on a support having a hydrophobic surface, and an undercoat layer is coated thereon. By these treatments, good adhesion and applicability between the support and the undercoat layer, the undercoat upper layer and the undercoat lower layer, and the undercoat upper layer and the hydrophilic layer can be obtained.

The corona discharge treatment is disclosed in, for example, JP-B-48-5043, JP-A-47-51905, JP-A-47-28067, JP-A-49-83767, JP-A-51-41770, JP-A-51-131576. Can be achieved by different methods. The discharge frequency is 50 to 5000 kHz, preferably 5 to several hundred kHz. Regarding the treatment strength of the object to be treated, 0.001 to 5 kV · A · min / m ² , preferably 0.01 to 1 kV · A · min / m ² is appropriate for improving wettability. The gap clearance between the electrode and the dielectric roll is 0.5 to 2.5 mm, preferably 1.0 to 2.0 mm.

The glow discharge treatment is, for example, U.S. Pat. Nos. 3,057,792, 3,057,795, 3,179,482, 3,288,638, and 3,309,299. No. 3,424,735, No. 3,462,335, No. 3,475,307, No. 3,761,299, British Patent No. 997,093, etc. be able to. As for the glow discharge treatment conditions, the pressure is generally 0.005 to 20 Torr, preferably 0.02 to 2 Torr (1 Torr is 133.32 Pa). The discharge is generated by applying a high voltage between metal plates or metal bars arranged in a vacuum tank with a pair of spaces or more. This voltage can take various values depending on the composition and pressure of the atmospheric gas, but usually a stable steady glow discharge occurs between 500 and 5000 V within the above pressure range. A particularly suitable voltage range for improving the adhesiveness is 2000 to 4000V. Further, as seen in the prior art, the discharge frequency is suitably several thousand MHz from DC, preferably 50 to 20 MHz. With respect to the strength of the discharge treatment, 0.01 to 5 kV · A · min / m ² , preferably 0.15 to 1 kV · A · min / m ² is appropriate since desired adhesive performance can be obtained. The discharge atmosphere gas composition during the glow discharge treatment preferably has a water vapor partial pressure of 10% to 100%, more preferably 40% to 90%. The gas other than water vapor is air composed of oxygen, nitrogen and the like. In such a method of quantitatively introducing water vapor into the glow discharge treatment atmosphere, a gas is introduced from a sampling tube attached to the glow discharge treatment apparatus to a quadrupole mass spectrometer (MSQ-6150, manufactured by Nippon Vacuum Co., Ltd.). This can be achieved by quantitatively measuring. When the glow discharge treatment is performed in a state where the support to be surface-treated is preheated, the adhesion can be improved in a short time and the yellowing of the support can be greatly reduced. The preheating temperature is preferably 50 ° C. or more and a glass transition temperature (or glass transition point Tg), more preferably 70 ° C. or more and Tg or less, and further preferably 90 ° C. or more and Tg or less. Specific methods for raising the polymer surface temperature in a vacuum include heating with an infrared heater and heating by contacting with a hot roll. In the glow discharge treatment, it is preferable that a plurality of electrodes having an intermediate portion serving as a refrigerant flow path are disposed facing each other in the width direction of the film, and the treatment is performed while conveying the support. It is preferable to immediately lower the temperature of the support subjected to the glow discharge treatment using a cooling roll by the method described in JP-A-3-39106.

As a processing gas when performing plasma discharge, a gas capable of imparting a polar functional group such as an amino group, a carboxyl group, a hydroxyl group, or a carbonyl group is preferable. For example, nitrogen (N ₂ ) gas, hydrogen (H ₂ ) gas, oxygen There are (O ₂ ) gas, carbon dioxide (CO ₂ ) gas, ammonia (NH ₃ ) gas, water vapor and the like. Further, gaseous or gasified organic compounds, inorganic compound vapors, and the like can also be used. In addition to the reaction gas, an inert gas such as helium or argon is necessary, and a stable discharge condition can be obtained by setting the gas mixing ratio to 60% or more. However, in the case of generating plasma with a pulsed electric field, an inert gas is not always necessary, and the reaction gas concentration can be increased. A frequency range of 1 to 100 kHz of the pulse electric field is preferable. The time during which one pulse electric field is applied is preferably 1 to 1000 μs, and the magnitude of the voltage applied to the electrode is preferably in the range where the electric field strength is 1 to 100 kV / cm.

Others In the undercoat layer of the present invention, the following inorganic particles can be used. Examples thereof include inorganic substances such as silica, alumina, barium sulfate, calcium carbonate, titania, tin oxide, indium oxide, and talc. The shape of these fine particles is not particularly limited, and can be used in a needle shape, a spherical shape, a plate shape, or a crushed shape. A preferable size is 0.1 to 15 μm, more preferably 0.2 to 10 μm, and still more preferably 0.3 to 7 μm. The amount of particles added is 0.1 to 50 mg, more preferably 0.2 to 30 mg, and still more preferably 0.3 to ²⁰ mg per 1 m ^{2 on} one side.

  The undercoat layer of the present invention is preferably 0.05 to 0.50 μm from the viewpoint of transparency and coating unevenness (interference unevenness). More preferably, it is 0.10 to 0.30 μm. If it is less than 0.05 μm, the desired adhesiveness cannot be obtained, and the on-press developability, registration deviation and printing durability are deteriorated, which is not preferable. Further, when the thickness is 0.50 μm or more, interference unevenness is strong, which is not preferable in terms of commercial value.

  In the present invention, the undercoat layer is formed by applying a coating solution on one side or both sides of a polyester film before the completion of crystal orientation, particularly after the support is formed. It is preferable to apply the coating solution on one or both sides of the film.

  As the coating method for the undercoat layer of the present invention, any known coating method can be applied. For example, kiss coat method, reverse coat method, die coat method, reverse kiss coat method, offset gravure coat method, Mayer bar coat method, roll brush method, spray coat method, air knife coat method, impregnation method, curtain coat method, etc. alone or in combination To apply.

  It is preferable to provide an antistatic layer on the undercoat layer of the present invention. The antistatic layer is composed of an antistatic agent and a binder.

A metal oxide is preferably used as the antistatic agent. Examples of metal oxides are preferably ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₃ , V ₂ O ₅ , or a composite oxide thereof. In particular, SnO ₂ (tin oxide) is preferable from the viewpoints of miscibility with the binder, conductivity, transparency, and the like. As an example including a different element, Sb, Nb, a halogen element or the like can be added to SnO ₂ . The amount of these different elements added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%.

  The tin oxide of the present invention is preferably in the form of an amorphous sol or crystalline particles. In the case of water-based coating, an amorphous sol is preferable, and in the case of solvent-based coating, the form of crystalline particles is preferable. In particular, from the viewpoint of workability, the form of an amorphous sol with an aqueous coating is preferable from the viewpoint of workability.

Regarding the method for producing an amorphous SnO ₂ sol that can be used in the present invention, it is produced from a method in which SnO ₂ fine particles are dispersed in an appropriate solvent, or a decomposition reaction of a Sn compound that is soluble in the solvent in the solvent. Any method may be used. A method for producing from a decomposition reaction of a Sn compound soluble in a solvent in the solvent will be described below. Sol-soluble Sn compounds include compounds containing an oxo anion such as K ₂ SnO ₃ .3H ₂ O, water-soluble halides such as SnCl ₄ , R ′ ₂ SnR ₂ , R ₃ SnX, R ₂ For example, (CH ₃ ) ₃ SnCl · (pyridine), (C ₄ H ₉ ) ₂ Sn (O ₂ CC ₂ H ₅ ) _{2 and} other organometallic compounds having the structure of SnX ₂ , Sn (SO ₄ ) ₂ · 2H ₂ O And oxo salts such as After Sn compounds soluble in these solvents are dissolved in the solvent, SnO ₂ sols are produced by physical methods such as heating and pressurization, chemical methods such as oxidation, reduction, and hydrolysis, or intermediate For example, a method of producing a SnO ₂ sol after passing through the body. As an example, a method for producing a SnO ₂ sol described in Japanese Patent Publication No. 35-6616 will be described. First, SnCl ₄ is dissolved in 100 volumes of distilled water to form a precipitate of Sn (OH) ₄ as an intermediate. When aqueous ammonia is added to make it slightly alkaline and then heated until the ammonia odor disappears, a colloidal SnO ₂ sol is obtained. In the examples, water was used as the solvent, but alcohol solvents such as methanol, ethanol and isopropanol, ether solvents such as tetrahydrofuran, dioxane and diethyl ether, aliphatic organic solvents such as hexane and heptane, and aromatics such as benzene and pyridine. Various solvents such as group organic solvents can be used depending on the Sn compound, and the present invention does not limit the solvent. Preferably, water and alcohol solvents are selected.

  On the other hand, the crystalline particles are described in detail in JP-A-56-143430 and JP-A-60-258541. The conductive metal oxide fine particles can be prepared by first firing the metal oxide fine particles by firing and then heat-treating them in the presence of different atoms to improve conductivity, and secondly by oxidizing the metal oxides by firing. Single and combined methods such as a method of allowing different atoms to coexist at the time of manufacturing fine particles, and a method of introducing an oxygen defect by lowering the oxygen concentration at the time of firing are used.

The average particle diameter of the primary particles of the metal oxide used in the present invention is preferably 0.001 to 0.5 μm, particularly preferably 0.001 to 0.2 μm. The solid amount of the metal oxide used in the present invention is preferably 0.05 to ² g, more preferably 0.1 to 1 g per 1 m ² . The volume fraction of the metal oxide in the antistatic layer in the present invention is 8 to 40 vol%, preferably 10 to 35 vol%. Although the said range changes with the color, form, composition, etc. of metal oxide fine particles, the said range is the most preferable from the point of transparency and electroconductivity.

  On the other hand, the binder is preferably polyester, acrylic modified polyester, polyurethane, acrylic resin, vinyl resin, vinylidene chloride resin, polyethyleneimine vinylidene resin, polyethyleneimine, polyvinyl alcohol, modified polyvinyl alcohol, cellulose ester, gelatin and the like.

  Examples of the material used for the hydrophilic layer of the printing plate material of the present invention include the following. The material forming the hydrophilic matrix is preferably a metal oxide, more preferably metal oxide fine particles.

  Examples include colloidal silica, alumina sol, titania sol, and other metal oxide sols. The metal oxide may have any shape such as a spherical shape, a feather shape, and the like, and the average particle size is 3 to 100 nm. However, several kinds of metal oxide fine particles having different average particle diameters can be used in combination. Further, the surface of the particles may be subjected to a surface treatment.

  The metal oxide particles can be used as a binder by utilizing the film forming property. The decrease in hydrophilicity is less than when an organic binder is used, and it is suitable for use in a hydrophilic layer.

  Among the above, colloidal silica can be preferably used in the present invention. Colloidal silica has the advantage of high film-forming properties even under relatively low temperature drying conditions, and can provide good strength.

  The colloidal silica preferably includes a necklace-shaped colloidal silica, which will be described later, and a fine particle colloidal silica having an average particle size of 20 nm or less, and the colloidal silica preferably exhibits alkalinity as a colloidal solution.

  The necklace-like colloidal silica used in the present invention is a general term for the water dispersion diameter of spherical silica whose primary particle diameter is on the order of nm.

  The necklace-shaped colloidal silica used in the present invention means “pearl necklace-shaped” colloidal silica in which spherical colloidal silica having a primary particle diameter of 10 to 50 nm is bonded to a length of 50 to 400 nm.

  A pearl necklace shape (that is, a pearl necklace shape) means that an image in a state in which silica particles of colloidal silica are joined together and connected is shaped like a pearl necklace.

  The bond between the silica particles constituting the necklace-shaped colloidal silica is presumed to be —Si—O—Si— in which —SiOH groups present on the surface of the silica particles are dehydrated.

  Specific examples of the colloidal silica in the form of necklace include “Snowtex-PS” series manufactured by Nissan Chemical Industries, Ltd.

As product names, “Snowtex-PS-S (average particle size in a connected state is about 110 nm)”, “Snowtex-PS-M (average particle size in a connected state is about 120 nm)” and “Snowtex- PS-L (the average particle size of the linked state is about 170 nm) ", and acidic products corresponding to these are" Snowtex-PS-SO "," Snowtex-PS-MO "and “Snowtex-PS-LO”.
By adding necklace-like colloidal silica, it becomes possible to maintain the strength while ensuring the porosity of the layer, and it can be preferably used as a porous material for the hydrophilic layer matrix. Among these, when using “Snowtex PS-S”, “Snowtex-PS-M” and “Snowtex-PS-L” which are alkaline, the strength of the hydrophilic layer is improved and the number of printed sheets is large. However, it is particularly preferable because the occurrence of soiling is suppressed.
In addition, it is known that colloidal silica has a stronger binding force as the particle system is smaller. In the present invention, it is preferable to use colloidal silica having an average particle diameter of 20 nm or less, and more preferably 3 to 15 nm. . Further, as described above, it is particularly preferable to use alkaline colloidal silica because the alkaline substance has a high effect of suppressing the occurrence of soiling in the colloidal silica.

  Alkaline colloidal silica with an average particle size in this range Nissan Chemical's “Snowtex 20 (particle diameter 10-20 nm)”, “Snowtex-30 (particle system 10-20 nm)”, “Snowtex-40 (particles) "Snowtex-N (particle diameter 10-20 nm)", "Snowtex-S (particle diameter 8-11 nm)", "Snowtex-XS (particle diameter 4-6 nm)" It is done.

  Colloidal silica having an average particle size of 20 nm or less is particularly preferred because it can be further improved in strength while maintaining the porosity of the layer when used in combination with the aforementioned necklace-shaped colloidal silica.

  The ratio of colloidal silica / necklace-shaped colloidal silica having an average particle diameter of 20 nm or less is preferably 95/5 to 5/95, more preferably 70/30 to 20/80, and still more preferably 60/40 to 30/70.

  As the porous material of the hydrophilic layer matrix of the present invention, porous metal oxide particles having a particle size of less than 1 μm can be contained. As the porous metal oxide particles, porous silica, porous aluminosilicate particles, or zeolite particles described later can be preferably used.

  The porous silica particles are generally produced by a wet method or a dry method. In the wet method, it can be obtained by drying and pulverizing a gel obtained by neutralizing an aqueous silicate solution, or by pulverizing a precipitate deposited after neutralization. In the dry method, silicon tetrachloride is burned together with hydrogen and oxygen to obtain silica.

  These particles can be controlled in porosity and particle size by adjusting the production conditions. The porous silica particles are particularly preferably those obtained from a wet gel.

  The porous aluminosilicate particles are produced, for example, by the method described in JP-A-10-71764. That is, it is an amorphous composite particle synthesized by hydrolysis using aluminum alkoxide and silicon alkoxide as main components. The ratio of alumina to silica in the particles can be synthesized in the range of 1: 4 to 4: 1. In addition, particles produced by adding other metal alkoxides at the time of production as composite particles having three or more components can also be used in the present invention. These composite particles can also control the porosity and particle size by adjusting the production conditions.

  The porosity of the particles is preferably 0.5 ml / g or more in terms of pore volume, more preferably 0.8 ml / g or more, and further preferably 1.0 to 2.5 ml / g or less. preferable.

  The pore volume is closely related to the water retention of the coating film. The larger the pore volume, the better the water retention, the less likely to get stained during printing, and the greater the water volume latitude, but greater than 2.5 ml / g. Then, since the particles themselves become very brittle, the durability of the coating film decreases. When the pore volume is less than 0.5 ml / g, the printing performance may be slightly insufficient.

  Zeolite can also be used as the porous material of the present invention.

  Zeolite is a crystalline aluminosilicate and is a porous body having regular three-dimensional network voids having a pore diameter of 0.3 to 1 nm. The general formula combining natural and synthetic zeolite is expressed as follows:

(M ₁ , M ₂ 1/2) _m (Al _m Si _n O _{2 (m + n)} ) · xH ₂ O
Here, M ₁ and M ₂ are exchangeable cations, and M ₁ is Li ⁺ , Na ⁺ , K ⁺ , Tl ⁺ , Me ₄ N ⁺ (TMA), Et ₄ N ⁺ (TEA), Pr _4. N ⁺ (TPA), C ₇ H ₁₅ N ²⁺ , C ₈ H ₁₆ N ^{+ and the} like, and M ₂ is Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , Sr ²⁺ , C ₈ H ₁₈ N ₂ ^{2. +} Etc. Further, n ≧ m, and the value of m / n, that is, the Al / Si ratio is 1 or less. It can be said that the higher the Al / Si ratio, the higher the polarity because it is considered that there are more solid acid points, and therefore higher hydrophilicity. A preferable Al / Si ratio is 0.4 to 1.0, and more preferably 0.8 to 1.0. x represents an integer.

As the zeolite fine particles used in the present invention, a synthetic zeolite having a stable Al / Si ratio and a relatively sharp particle size distribution is preferable. For example, zeolite A: Na ₁₂ (Al ₁₂ Si ₁₂ O ₄₈ ) 27H ₂ O; Al / Si ratio 1.0, zeolite X: Na ₈₆ (Al ₈₆ Si ₁₀₆ O ₃₈₄ ) • 264H ₂ O; Al / Si ratio 0.811, zeolite Y: Na ₅₆ (Al ₅₆ Si ₁₃₆ O ₃₈₄ ) · 250H ₂ O; Al / Si ratio 0.412 and the like.

  By containing highly hydrophilic porous particles having an Al / Si ratio of 0.4 to 1.0, the hydrophilicity of the hydrophilic layer itself is greatly improved, it is difficult to get dirty during printing, and the water latitude is widened. In addition, the dirt on the fingerprint marks is greatly improved. When the Al / Si ratio is less than 0.4, the hydrophilicity is insufficient, and the effect of improving the performance becomes small.

  Moreover, the hydrophilic layer matrix of the printing plate material of the present invention can contain layered clay mineral particles. Examples of the layered mineral particles include kaolinite, halloysite, talc, smectite (montmorillonite, beidellite, hectorite, sabonite, etc.), clay minerals such as vermiculite, mica (mica), chlorite, hydrotalcite, layered polysilicate ( Kanemite, macatite, ialite, magadiite, kenyaite, etc.). Among them, it is considered that the higher the charge density of the unit layer (unit layer), the higher the polarity and the higher the hydrophilicity. The charge density is preferably 0.25 or more, more preferably 0.6 or more. Examples of the layered mineral having such a charge density include smectite (charge density 0.25 to 0.6; negative charge), vermiculite (charge density 0.6 to 0.9; negative charge) and the like. In particular, synthetic fluoromica is preferable because it can be obtained with stable quality such as particle size. Among the synthetic fluorine mica, those that are swellable are preferable, and those that are free swell are more preferable.

  Also used are intercalation compounds of the above-mentioned layered minerals (pillar crystals, etc.), those subjected to ion exchange treatment, and those subjected to surface treatment (silane coupling treatment, compounding treatment with organic binder, etc.) can do.

  As the size of the flat lamellar mineral particles, the average particle diameter (maximum length of the particles) is less than 1 μm in the state of being contained in the layer (including the case where the swelling process and the dispersion peeling process have been performed). The aspect ratio is preferably 50 or more. When the particle size is in the above range, the continuity and flexibility in the planar direction, which are the characteristics of the thin layered particles, are imparted to the coating film, and it is difficult for cracks to occur, and a tough coating film can be obtained in a dry state. Moreover, in the coating liquid containing many particulate matters, sedimentation of particulate matter can be suppressed by the thickening effect of the layered clay mineral. When the particle diameter is larger than the above range, the coating film may be non-uniform, and the strength may be locally reduced. On the other hand, when the aspect ratio is not more than the above range, the number of tabular grains with respect to the addition amount is reduced, the viscosity is insufficient, and the effect of suppressing sedimentation of the particulate matter is reduced.

  The content of the layered mineral particles is preferably 0.1 to 30% by mass, and more preferably 1 to 10% by mass based on the entire layer. In particular, swellable synthetic fluorinated mica and smectite are preferable because they are effective even when added in a small amount. The layered mineral particles may be added as a powder to the coating solution, but in order to obtain a good degree of dispersion even with a simple preparation method (no need for a dispersion step such as media dispersion), the layered mineral particles are used alone. It is preferable that the gel swollen in water is prepared and then added to the coating solution.

A silicate aqueous solution can also be used as another additive material in the hydrophilic layer matrix of the present invention. Alkali metal silicates such as silicate Na, silicate K, and silicate Li are preferred, and the SiO ₂ / M ₂ O ratio is in a range where the pH of the entire coating solution does not exceed 13 when silicate is added. It is preferable to select such that the inorganic particles are not dissolved.

  Further, an inorganic polymer or an organic-inorganic hybrid polymer using a metal alkoxide by a so-called sol-gel method can also be used. The formation of an inorganic polymer or an organic-inorganic hybrid polymer by the sol-gel method is described in, for example, “Application of the sol-gel method” (Sakuo Sakuo / Published by Agne Jofusha) or cited in this book. Known methods described in the published literature can be used.

  Moreover, you may contain water-soluble resin. Examples of water-soluble resins include polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, styrene-butadiene copolymer, conjugated diene polymer latex of methyl methacrylate-butadiene copolymer, acrylic Examples thereof include resins such as polymer polymer latex, vinyl polymer latex, polyacrylamide, and polyvinylpyrrolidone. However, it is preferable to use a polysaccharide as the water-soluble resin used in the present invention.

  As polysaccharides, starches, celluloses, polyuronic acids, pullulans and the like can be used, but cellulose derivatives such as methyl cellulose salts, carboxymethyl cellulose salts, hydroxyethyl cellulose salts are particularly preferable, and sodium salts and ammonium salts of carboxymethyl cellulose are preferable. More preferred.

  This is because an effect of forming the surface shape of the hydrophilic layer in a preferable state can be obtained by including the polysaccharide in the hydrophilic layer.

  The surface of the hydrophilic layer preferably has a concavo-convex structure with a pitch of 0.1 to 20 μm like the aluminum grain of the PS plate, and this concavo-convex improves water retention and image area retention.

  Such a concavo-convex structure can be formed by adding an appropriate amount of a filler having an appropriate particle size to the hydrophilic layer matrix. However, the above-mentioned alkaline colloidal silica and the above-mentioned water-soluble solution are added to the hydrophilic layer coating solution. It is preferable that a structure having better printability can be obtained by forming a phase separation when the hydrophilic polysaccharide is applied and dried.

  The shape of the concavo-convex structure (such as pitch and surface roughness) is the type and amount of alkaline colloidal silica, the type and amount of water-soluble polysaccharides, the type and amount of other additives, the solid content concentration of the coating solution, and the wet film. The thickness and drying conditions can be appropriately controlled.

  The water-soluble resin added to the hydrophilic matrix in the present invention is preferably present in a state where at least a part thereof is water-soluble and can be eluted in water. This is because even if it is a water-soluble material, when it is cross-linked by a cross-linking agent or the like and becomes insoluble in water, its hydrophilicity is lowered and printability may be deteriorated.

  In addition, a cationic resin may be further included. Examples of the cationic resin include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine or derivatives thereof, and acrylic having a tertiary amino group or a quaternary ammonium group. Examples thereof include resins and diacrylamine. The cationic resin may be added in the form of fine particles. Examples thereof include a cationic microgel described in JP-A-6-161101.

  The hydrophilic layer coating solution of the present invention may contain a water-soluble surfactant for the purpose of improving coating properties. A surfactant such as Si-based or F-based can be used, but it is particularly preferable to use a surfactant containing Si element because there is no fear of causing printing stains. The content of the surfactant is preferably 0.01 to 3% by mass, more preferably 0.03 to 1% by mass, based on the entire hydrophilic layer (solid content as the coating solution).

  In addition, the hydrophilic layer of the present invention can contain a phosphate. In the present invention, since the hydrophilic layer coating solution is preferably alkaline, the phosphate is preferably added as trisodium phosphate or disodium hydrogen phosphate. By adding phosphate, the effect of improving the mesh opening at the time of printing can be obtained. The addition amount of phosphate is preferably 0.1 to 5% by mass, and more preferably 0.5 to 2% by mass as an effective amount excluding hydrate.

  Moreover, the photothermal conversion raw material mentioned later can also be contained. As the photothermal conversion material, in the case of a particulate material, the particle size is preferably less than 1 μm.

  In this invention, it is preferable to contain the particle | grains coat | covered with the inorganic particle or particle | grains with a particle size of 1 micrometer or more.

Porous, nonporous, organic resin particles, and inorganic fine particles may be used. As inorganic fillers, silica, alumina, zirconia, titania, carbon black, graphite, TiO ₂ , BaSO ₄ , ZnS, MgCO ₃ , CaCO _{3, ZnO, CaO, WS 2} , MoS 2, MgO, SnO 2, Al 2 O 3, α-Fe 2 O 3, α-FeOOH, SiC, CeO 2, BN, SiN, MoC, BC, WC, titanium carbide Corundum, artificial diamond, garnet, garnet, silica, triboli, diatomaceous earth, dolomite, etc., organic fillers include polyethylene fine particles, fluororesin particles, guanamine resin particles, acrylic resin particles, silicon resin particles, melamine resin particles, etc. I can list them. Examples of the inorganic filler include particles obtained by coating a core of organic particles such as PMMA, polystyrene, and melamine with inorganic particles that are smaller than the core particles. The particle size of the inorganic particles is preferably about 1/10 to 1/100 of the core particles. As the inorganic particles, similarly known metal oxide particles such as silica, alumina, titania, zirconia can be used. As the coating method, various known methods can be used, but the core material particles and the coating material particles are collided at high speed in the air like a hybridizer to cause the coating material particles to bite into the surface of the core material particles. A dry coating method of fixing and coating can be preferably used.

  Moreover, the particle | grains which carried out the metal plating of the core material of an organic particle can also be used. Examples of such particles include “Micropearl AU” manufactured by Sekisui Chemical Co., Ltd., in which resin particles are plated with gold.

  In the present invention, any filler that satisfies the scope of the present invention can exert its effect without any particular limitation. In particular, in order to suppress sedimentation in the coating solution, porous silica particles, porous aluminosilicate particles, etc. It is preferable to use a porous inorganic filler or a porous inorganic filler.

  The particle size is preferably 1 to 12 μm, more preferably 1.5 to 8 μm, and further preferably 2 to 6 μm.

  When the particle diameter exceeds 12 μm, there is a concern that the resolution of image formation is reduced and the blanket stain is deteriorated.

  The amount of particles having a particle diameter of 1 μm or more is preferably 1 to 50% by mass, more preferably 5 to 40% by mass based on the entire hydrophilic layer.

  The hydrophilic layer as a whole preferably has a low content ratio of materials containing carbon such as organic resin and carbon black in order to improve hydrophilicity, and the total of these materials is preferably less than 9% by mass. More preferably, it is less than 5 mass%.

  As a form of the present invention, a lower layer may be provided.

  When a lower layer is provided, the same material as the hydrophilic layer can be used as the material used for the lower layer.

  However, the lower layer is less advantageous in that it is porous, and the nonporous material improves the coating strength, so the content of the porous material of the hydrophilic matrix is higher than that of the hydrophilic layer. Is preferably less, more preferably not contained.

  The addition amount of the particles having a particle size of 1 μm or more is preferably 1 to 50% by mass, more preferably 5 to 40% by mass based on the entire lower layer.

  Similarly to the hydrophilic layer as the entire lower layer, a low content ratio of materials containing carbon such as organic resin and carbon black is preferable for improving hydrophilicity, and the total of these materials is less than 9% by mass. It is preferable that it is less than 5% by mass.

  The image forming functional layer containing the heat-fusible and / or heat-fusible fine particles of the present invention can contain the following materials.

  The heat-meltable fine particles used in the present invention are fine particles formed of a material that has a low viscosity when melted, and is generally classified as a wax, among thermoplastic materials. The physical properties are preferably a softening point of 40 ° C. or higher and 120 ° C. or lower, a melting point of 60 ° C. or higher and 150 ° C. or lower, more preferably a softening point of 40 ° C. or higher and 100 ° C. or lower, and a melting point of 60 ° C. or higher and 120 ° C. or lower. When the melting point is less than 60 ° C., storage stability is a problem, and when the melting point is higher than 300 ° C., ink deposition sensitivity is lowered.

Usable materials include paraffin, polyolefin, polyethylene wax, microcrystalline wax, fatty acid wax and the like. These have a molecular weight of about 800 to 10,000. In order to facilitate emulsification, these waxes can be oxidized to introduce polar groups such as hydroxyl groups, ester groups, carboxyl groups, aldehyde groups, and peroxide groups. Furthermore, in order to lower the softening point and improve the workability, these waxes are stearamide, linolenamide, laurylamide, myristamide, hardened beef fatty acid amide, palmitoamide, oleic acid amide, rice sugar fatty acid amide, coconut fatty acid amide. Alternatively, methylolated products of these fatty acid amides, methylene bisstellaramide, ethylene bisstellaramide, and the like can be added. Coumarone-indene resin, rosin-modified phenol resin, terpene-modified phenol resin, xylene resin, ketone resin, acrylic resin, ionomer, and copolymers of these resins can also be used.
Among these, it is preferable to contain any of polyethylene, microcrystalline, fatty acid ester, fatty acid amide, and fatty acid. Since these materials have a relatively low melting point and a low melt viscosity, high-sensitivity image formation can be performed. In addition, since these materials have lubricity, damage when a shearing force is applied to the surface of the printing plate material is reduced, and resistance to printing stains due to scratches or the like is improved.

  The heat-meltable fine particles are preferably dispersible in water, and the average particle size is preferably 0.01 to 10 μm, more preferably 0.1 to 3 μm. When the average particle size is smaller than 0.1 μm, when the coating solution for the layer containing the heat-fusible fine particles is applied on the porous hydrophilic layer described later, the heat-fusible fine particles become pores of the hydrophilic layer. It becomes easy to enter inside or into the gaps between fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause scumming. When the average particle size of the heat-meltable fine particles is larger than 10 μm, the resolution is lowered.

  Further, the composition of the heat-meltable fine particles may vary continuously between the inside and the surface layer, or may be coated with a different material.

  As a coating method, a known microcapsule formation method, a sol-gel method, or the like can be used. As content of the heat-meltable microparticles | fine-particles in a layer, 1-90 mass% of the whole layer is preferable, and 5-80 mass% is more preferable.

  Examples of the heat-fusible fine particles of the present invention include thermoplastic hydrophobic polymer fine particles, and there is no specific upper limit for the softening temperature of the thermoplastic hydrophobic high-molecular polymer particles, but the temperature is high. It is preferably lower than the decomposition temperature of the coalesced fine particles. The mass average molecular weight (Mw) of the polymer is preferably in the range of 10,000 to 1,000,000.

  Specific examples of the polymer constituting the polymer particles include, for example, diene (co) polymers such as polypropylene, polybutadiene, polyisoprene and ethylene-butadiene copolymer, styrene-butadiene copolymer, Synthetic rubbers such as methyl methacrylate-butadiene copolymer, acrylonitrile-butadiene copolymer, polymethyl methacrylate, methyl methacrylate- (2-ethylhexyl acrylate) copolymer, methyl methacrylate-methacrylic acid copolymer, methyl acrylate- ( N-methylolacrylamide) copolymer, (meth) acrylic acid ester such as polyacrylonitrile, (meth) acrylic acid (co) polymer, polyvinyl acetate, vinyl acetate-vinyl propionate copolymer, vinyl acetate-ethylene copolymer Vinyl etc. of polymers Ester (co) polymer, vinyl acetate - (2-ethylhexyl acrylate) copolymers, polyvinyl chloride, polyvinylidene chloride, polystyrene and copolymers thereof. Of these, (meth) acrylic acid esters, (meth) acrylic acid (co) polymers, vinyl ester (co) polymers, polystyrene, and synthetic rubbers are preferably used.

  The polymer polymer fine particles may be composed of a polymer polymer polymerized by any known method such as emulsion polymerization, suspension polymerization, solution polymerization, and gas phase polymerization. As a method of microparticulating a polymer polymer polymerized by a solution polymerization method or a gas phase polymerization method, a method of spraying a solution in an organic solvent of the polymer polymer into an inert gas and drying to form particles, Examples thereof include a method in which a high molecular weight polymer is dissolved in a water-immiscible organic solvent, this solution is dispersed in water or an aqueous medium, and the organic solvent is distilled off to form fine particles. In any of the methods, a surfactant, such as sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyethylene glycol, or a water-soluble resin, such as polyvinyl alcohol, is used as a dispersant or stabilizer in polymerization or micronization as necessary. May be used.

  The thermoplastic fine particles are preferably dispersible in water, and the average particle diameter is preferably 0.01 to 10 μm, more preferably 0.1 to 3 μm. When the average particle size is smaller than 0.01 μm, when the coating liquid for the layer containing the heat-meltable fine particles is applied onto the porous hydrophilic layer described later, the heat-meltable fine particles are not removed from the pores of the hydrophilic layer. It becomes easy to enter inside or into the gaps between fine irregularities on the surface of the hydrophilic layer, and the on-press development becomes insufficient, which may cause scumming. When the average particle size of the heat-meltable fine particles is larger than 10 μm, the resolution is lowered.

  The image-forming functional layer containing the heat-fusible and / or heat-fusible fine particles of the present invention can further contain a water-soluble material. By including the water-soluble material, when the image forming functional layer in the unexposed area is removed using dampening water or ink on the printing press, the removability can be improved.

  As the water-soluble material, the water-soluble resins mentioned as materials that can be contained in the hydrophilic layer can also be used. However, as the image forming functional layer of the present invention, it is preferable to use saccharides, particularly oligosaccharides. Is preferred.

Since the oligosaccharide dissolves quickly in water, the image forming functional layer in the unexposed area on the printing device can be removed very quickly, and the normal PS plate printing operation can be performed without being aware of the special removal operation. Can be removed by printing in the same manner as in the above, and printing waste paper does not increase.
In addition, the oligosaccharide can maintain good printability of the hydrophilic layer without concern for lowering the hydrophilicity of the hydrophilic layer.

  An oligosaccharide is a crystalline substance that is soluble in water and generally sweet, and is obtained by dehydrating and condensing several monosaccharides by glycosidic bonds. Oligosaccharide is a kind of o-glycoside with sugar as aglycone, so it is easily hydrolyzed with acid to produce monosaccharide, and disaccharide, trisaccharide, tetrasaccharide, pentasaccharide, etc. depending on the number of molecules of monosaccharide produced are categorized. The oligosaccharide in the present invention refers to those from disaccharide to decasaccharide.

  These oligosaccharides are roughly classified into reducing oligosaccharides and non-reducing oligosaccharides depending on the presence or absence of a reducing group, and are composed of homooligosaccharides composed of a single monosaccharide and two or more types of monosaccharides. It is also classified as a hetero-oligosaccharide.

  Oligosaccharides exist naturally as free or glycosides and can also be obtained by partial hydrolysis of polysaccharides with acids or enzymes. Various oligosaccharides are also produced by glycosyl transfer by other enzymes.

  Oligosaccharides often exist as hydrates in a normal atmosphere. Moreover, the melting point differs between hydrate and anhydride.

  In the present invention, it is preferable to coat and form a saccharide-containing layer with an aqueous solution. Therefore, when the oligosaccharide is formed from an aqueous solution, if the oligosaccharide present in the layer is an oligosaccharide that forms a hydrate, its melting point. Is considered to be the melting point of the hydrate. Thus, since it has a relatively low melting point, the oligosaccharide also melts in the temperature range in which the hot melt fine particles melt or in the temperature range in which the hot melt fine particles fuse, and the porous hydrophilic layer of the hot melt fine particles It does not hinder image formation such as melt penetration into the film and fusion of heat-fused fine particles.

  Among oligosaccharides, trehalose is commercially available in a relatively high purity state at a low cost, and despite its high solubility in water, its hygroscopicity is very low, and on-press developability and The storage stability is very good.

  In addition, when oligosaccharide hydrate is melted by heat to remove water of hydration and then solidified (for a short time after solidification), it becomes an anhydrous crystal, but trehalose has a melting point of anhydride higher than that of hydrate. It is characteristic that it is higher than 100 ° C. This means that the exposed portion is melted by infrared exposure and immediately after re-solidification, the exposed portion is in a state of being difficult to melt at a high melting point, and is effective in causing image defects during exposure such as banding.

  In order to achieve the object of the present invention, trehalose is particularly preferable among oligosaccharides. As content of the oligosaccharide in a layer, 1-90 mass% of the whole layer is preferable, and 10-80 mass% is more preferable.

Image formation of the printing plate material of one embodiment of the present invention can be performed by heat, but it is particularly preferable to perform image formation by exposure with an infrared laser.
More specifically, exposure relating to the present invention is preferably scanning exposure using a laser that emits light in the infrared and / or near-infrared region, that is, in the wavelength range of 700 to 1500 nm. A gas laser may be used as the laser, but it is particularly preferable to use a semiconductor laser that emits light in the near infrared region.

As an apparatus suitable for scanning exposure according to the present invention, any apparatus can be used as long as it can form an image on the surface of a printing plate material in accordance with an image signal from a computer using the semiconductor laser. Good.
In general,
(1) A method of exposing the entire surface of the printing plate material by performing two-dimensional scanning using one or a plurality of laser beams on the printing plate material held by the plate-like holding mechanism,
(2) The circumferential direction of the cylinder (main scanning direction) using one or a plurality of laser beams from the inside of the cylinder to the printing plate material held along the cylindrical surface inside the fixed cylindrical holding mechanism ), Scanning the entire surface of the printing plate material by moving it in a direction perpendicular to the circumferential direction (sub-scanning direction),
(3) A printing plate material held on the surface of a cylindrical drum that rotates about an axis as a rotating body is rotated in the circumferential direction (main scanning direction) by rotating the drum using one or a plurality of laser beams from the outside of the cylinder. ) And moving in the direction perpendicular to the circumferential direction (sub-scanning direction) to expose the entire surface of the printing plate material.

  In the present invention, the scanning exposure method (3) is particularly preferable, and the exposure method (3) is used particularly in an apparatus that performs exposure on a printing apparatus.

  In the printing plate material of the present invention, an image can also be formed by applying an oleophilic material directly to the surface of the hydrophilic layer in an image-like manner.

  As one of methods for imparting an oleophilic material to the image, a method using a known thermal transfer method can be mentioned. Specifically, there is a method in which a heat transfer type printer is used to image-transfer the heat-meltable ink from the ink ribbon having the heat-meltable ink layer to the hydrophilic layer surface with a thermal head.

  Also, using a digital proof device of an infrared laser heat-melt transfer method, a printing plate material is wound on an exposure drum with a hydrophilic layer on the outside, and an ink sheet further having a heat-meltable ink layer is printed on the ink sheet. There can also be mentioned a method in which the surface is wound in contact with the hydrophilic layer, imagewise exposure is performed with an infrared laser, and the heat-meltable ink is imagewise transferred onto the surface of the hydrophilic layer. In this case, the photothermal conversion material may be contained in the hydrophilic layer, the ink sheet side may be contained in any layer, or both may be contained.

  After forming an image with a heat-meltable ink on the hydrophilic layer, the printing plate material can be heated to further strengthen the adhesion between the hydrophilic layer and the image. When the hydrophilic layer contains a photothermal conversion material, this heat treatment can also be performed using infrared laser irradiation or flash exposure using a known xenon lamp or the like.

  Another method is a method using a known ink jet method. As the ink to be used, the oil-based ink disclosed in Japanese Patent No. 2995075, the hot melt ink disclosed in Japanese Patent Laid-Open No. 10-24550, and the Japanese Patent Laid-Open No. 10-157053 are disclosed. An oil-based ink in which solid and hydrophobic resin particles are dispersed at normal temperature, or an aqueous ink in which solid and hydrophobic thermoplastic resin particles are dispersed at normal temperature can be used, but as an aspect of the present invention, A radiation curable ink can be preferably used.

  The radiation curable ink used in the present invention is composed of at least a polymerizable compound. In addition, a coloring material can be added for the purpose of obtaining visible image quality.

  As the color material, a color material that can be dissolved or dispersed in the main component of the polymerizable compound, that is, various dyes and pigments can be used.

  When adding a pigment, since the dispersibility has a great influence on the degree of coloration, the pigment is appropriately dispersed. For the dispersion of the pigment, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, a paint shaker, or the like can be used. It is also possible to add a dispersant when dispersing the pigment. As the dispersant, it is preferable to use a polymer dispersant. Examples of the polymer dispersant include Solsperse series manufactured by Zeneca. Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment. Although the dispersion medium is a solvent or a polymerizable compound, the radiation curable ink used in the present invention is preferably solventless because it reacts and cures immediately after ink landing. If the solvent remains in the cured image, the solvent resistance deteriorates and the VOC of the remaining solvent arises. Therefore, it is preferable in view of dispersibility that the dispersion medium is not a solvent but a polymerizable compound, and among them, a monomer having the lowest viscosity is selected.

  For the dispersion, it is preferable that the average particle diameter is 0.08 to 0.5 μm, and the pigment, the dispersant, and the dispersion medium are selected so that the maximum particle diameter is 0.3 to 10 μm, preferably 0.3 to 3 μm. Set dispersion conditions and filtration conditions. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

  The colorant is preferably added in an amount of 0.1% to 10% by weight of the total ink.

  The radiation polymerizable compound is a radical polymerizable compound such as light described in JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, and the like. Photo-curing materials using a polymerizable composition and cationic polymerization-based photo-curing resins are known, and recently, photo-cation polymerization-based photo-curing resins that have been sensitized to a long wavelength region longer than visible light. Are also disclosed in, for example, JP-A-6-43633 and JP-A-8-324137.

  The radical polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, and may be any compound as long as it has at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. , Oligomers, polymers and the like having a chemical form. Only one kind of radically polymerizable compound may be used, or two or more kinds thereof may be used in combination at an arbitrary ratio in order to improve desired properties. A polyfunctional compound having two or more functional groups is more preferable than a monofunctional compound. More preferably, two or more polyfunctional compounds are used in combination for controlling performance such as reactivity and physical properties.

  Examples of compounds having an ethylenically unsaturated bond capable of radical polymerization include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and their salts, esters, urethanes, amides. And radically polymerizable compounds such as unsaturated monomers, acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes. Specifically, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane, neopentyl glycol Diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol Tetraacrylate, dipentaery Acrylic acid derivatives such as lithol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, N-methylol acrylamide, diacetone acrylamide, epoxy acrylate, methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate , Lauryl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylol Methacryl derivatives such as tantrimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, and other derivatives of allyl compounds such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate More specifically, Yamashita Junzo, “Crosslinker Handbook”, (1981 Taiseisha); Kato Kiyomi, “UV / EB Curing Handbook (Materials)” (1985, Polymer Publication) ); Rad-Tech Study Group, “Application and Market of UV / EB Curing Technology”, p. 79, (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo Shimbun) Commercially available products described in the above, or radically polymerizable or crosslinkable monomers known in the industry Oligomers and polymers can be used. The amount of the radical polymerizable compound added is preferably 1 to 97% by mass, more preferably 30 to 95% by mass.

  Cationic polymerization type photo-curing resin includes monomers that are polymerized by cationic polymerization (mainly epoxy type), epoxy-type UV curable prepolymer, prepolymer containing two or more epoxy groups in one molecule. Etc. Examples of such prepolymers include alicyclic polyepoxides, polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycols, and polyglycidyls of aromatic polyols. Examples include ethers, hydrogenated compounds of polyglycidyl ethers of aromatic polyols, urethane polyepoxy compounds, and epoxidized polybutadienes. One of these prepolymers can be used alone, or two or more thereof can be mixed and used.

  In the present invention, (meth) acrylic monomers or prepolymers, epoxy monomers or prepolymers, urethane monomers or prepolymers are preferably used as the polymerizable compound, and the following compounds are more preferable.

  2-ethylhexyl-diglycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxybutyl acrylate, hydroxypivalate neopentyl glycol diacrylate, 2-acryloyloxyethyl phthalate, methoxy-polyethylene glycol acrylate, tetramethylol Methane triacrylate, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, dimethylol tricyclodecane diacrylate, ethoxylated phenyl acrylate, 2-acryloyloxyethyl succinic acid, nonylphenol EO adduct acrylate, modified glycerin triacrylate Bisphenol A diglycidyl ether acrylic acid adduct, modified bisphenol A diacrylate, phenoxy-polyethylene Glycol acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, bisphenol A PO adduct diacrylate, bisphenol A EO adduct diacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate tolylene diisocyanate urethane prepolymer, lactone Modified towable acrylate, butoxyethyl acrylate, propylene glycol diglycidyl ether acrylic acid adduct, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, 2-hydroxyethyl acrylate, methoxydipropylene glycol acrylate, ditrimethylolpropane tetraacrylate, penta Erythritol triacrylate hexamethylene Isocyanate urethane prepolymer, stearyl acrylate, isoamyl acrylate, isomyristyl acrylate, can be mentioned iso-stearyl acrylate.

  These acrylate compounds have lower skin irritation and sensitization (rash) than the polymerizable compounds conventionally used in UV curable inks, can relatively reduce viscosity, and provide stable ink ejection properties. Further, the polymerization sensitivity and the adhesion to the recording medium are also good. 20-95 mass% of the said compound group is used, Preferably it is 50-95 mass%, More preferably, 70-95 mass% is used.

  The monomers listed in the above-mentioned polymerizable compounds are low in sensitization even with a low molecular weight, and have high reactivity, low viscosity, and excellent permeability and adhesion to the hydrophilic layer. .

  Furthermore, in order to further improve sensitivity, bleeding, and adhesion to the hydrophilic layer, it is sensitivity to use the above-mentioned monoacrylate together with a polyfunctional acrylate monomer or polyfunctional acrylate oligomer having a molecular weight of 400 or more, preferably 500 or more. From the viewpoint of improving adhesion. While maintaining safety, the sensitivity, bleeding, and adhesion to the recording medium can be further improved. As the oligomer, an epoxy acrylate oligomer and a urethane acrylate oligomer are particularly preferable.

  It is preferable to use a monoacrylate selected from the above compound group in combination with a polyfunctional acrylate monomer or polyfunctional acrylate oligomer, because the film can be made flexible and the film strength can be increased while improving adhesion. As monoacrylate, stearyl acrylate, isoamyl acrylate, isomistyl acrylate, and isostearyl acrylate have high sensitivity, low shrinkage, and can suppress strength reduction due to internal stress in the image area, and also prevent bleeding, odor of printed matter, irradiation device This is preferable in terms of cost reduction.

  Although methacrylate has better skin irritation than acrylate, sensitization is generally not different from acrylate and is not suitable because it is less sensitive than acrylate, but it has high reactivity and good sensitization. If it is, it can be used suitably. Among the above compounds, alkoxy acrylate has low sensitivity and causes problems such as bleeding, odor, and irradiation light source. Therefore, it is preferable to keep the amount below 70 parts by mass and use other acrylates in combination. If necessary, other components can be added to the ink used in the present invention.

  When an electron beam, X-ray, or the like is used as irradiation light, an initiator is not necessary. However, when UV light, visible light, or infrared light is used as a radiation source, a radical polymerization initiator or initiator corresponding to each wavelength is used. Add auxiliaries and sensitizing dyes. These amounts require 1-10 parts by weight of the total ink. Various known compounds can be used as the initiator, but the initiator is selected from those that dissolve in the polymerizable compound. Specific examples of the initiator include xanthone or thiooxanthone series, benzophenone series, quinone series, and phosphine oxide series.

  Moreover, in order to improve preservability, 200-20000 ppm of polymerization inhibitors can be added. The ink of the present invention is preferably heated and reduced in viscosity in the range of 40 to 80 ° C. and ejected. Therefore, it is preferable to add a polymerization inhibitor in order to prevent head clogging due to thermal polymerization.

  In addition to this, surfactants, leveling additives, matting agents, polyester resins, polyurethane resins, vinyl resins, acrylic resins, rubber resins, and waxes are added to adjust film properties as necessary. I can do it. In order to improve adhesion to recording media such as olefin and PET, it is preferable to include a tackifier that does not inhibit polymerization. Specifically, high molecular weight adhesive polymers (esters of (meth) acrylic acid and alcohols having an alkyl group having 1 to 20 carbon atoms, described in JP-A-2001-49200 5-6p, (meta ) A copolymer of acrylic acid and an ester of an alicyclic alcohol having 3 to 14 carbon atoms, an ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms), or a polymerizable unsaturated bond A low molecular weight tackifying resin having

  In order to improve the adhesion with the hydrophilic layer, it is also effective to add a trace amount of organic solvent. In this case, it is effective to add in a range that does not cause the problem of solvent resistance and VOC, and the amount is 0.1 to 5%, preferably 0.1 to 3%.

  In addition, as a means for preventing a decrease in sensitivity due to the light-shielding effect due to the ink color material, it is possible to combine a cationically polymerizable monomer having a long initiator lifetime with an initiator to obtain a radical-cation hybrid curable ink.

  The composition ratio of the ink is determined so that the temperature at the time of ejection is preferably 7 to 30 mPa · s, more preferably 7 to 20 mPa · s in consideration of ejection properties. The ink viscosity at 25 ° C. is preferably 35 to 500 mPa · s, more preferably 35 to 200 mPa · s. By increasing the viscosity at room temperature, it is possible to prevent ink from penetrating into porous recording media, to reduce uncured monomers and to reduce odor, and to suppress dot bleeding at the time of landing, improving image quality. Is done. If it is less than 35 mPa · s, the effect of preventing bleeding is small. If it is higher than 500 mPa · s, a problem occurs in the delivery of the ink liquid.

  The surface tension is preferably 200 to 300 μN / cm, more preferably 230 to 280 μN / cm. If it is less than 200 μN / cm, there is concern in terms of bleeding and penetration, and if it exceeds 300 μN / cm, there is concern in terms of wettability.

  The hydrophilic layer, the lower layer, and the image forming layer of the present invention achieve high sensitivity by containing the following photothermal conversion material.

  In the present invention, the following metal oxide can be added to the hydrophilic layer as a photothermal conversion material.

  A material that exhibits black color in the visible light region, or a material that has conductivity or is a semiconductor can be used.

Examples of the former include black iron oxide (Fe ₃ O ₄ ) and black composite metal oxides containing two or more of the aforementioned metals.

Examples of the latter include SnO ₂ doped with Sb (ATO), In ₂ O ₃ doped with Sn (ITO), TiO ₂ , TiO ₂ with reduced TiO ₂ (titanium oxynitride, generally titanium black), etc. Is mentioned. Further, it can also be used those obtained by coating the core material _{(BaSO 4, TiO 2, 9Al} 2 O 3 · 2B 2 O, K 2 O · nTiO 2 , etc.) in these metal oxides. These particle sizes are 0.5 μm or less, preferably 100 nm or less, and more preferably 50 nm or less.

  Among these photothermal conversion materials, black composite metal oxides containing two or more metals are more preferable materials.

  Specifically, it is a composite metal oxide composed of two or more metals selected from Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sb, and Ba. These are disclosed by methods disclosed in JP-A-8-27393, JP-A-9-25126, JP-A-9-237570, JP-A-9-241529, JP-A-10-231441, and the like. Can be manufactured.

  The composite metal oxide used in the present invention is particularly preferably a Cu-Cr-Mn-based or Cu-Fe-Mn-based composite metal oxide. In the case of a Cu—Cr—Mn system, it is preferable to perform the treatment disclosed in JP-A-8-273393 in order to reduce the elution of hexavalent chromium. These composite metal oxides are colored with respect to the amount added, that is, they have good photothermal conversion efficiency.

  These composite metal oxides preferably have an average primary particle size of 1 μm or less, and more preferably have an average primary particle size in the range of 0.01 to 0.5 μm. When the average primary particle diameter is 1 μm or less, the photothermal conversion ability with respect to the addition amount becomes better, and when the average primary particle diameter is within the range of 0.01 to 0.5 μm, the photothermal conversion ability with respect to the addition amount is obtained. Better. However, the photothermal conversion ability with respect to the addition amount is greatly affected by the degree of dispersion of the particles, and the better the dispersion, the better. Therefore, it is preferable to disperse these composite metal oxide particles by a known method separately before adding them to the layer coating solution to prepare a dispersion (paste). An average primary particle size of less than 0.01 is not preferable because dispersion becomes difficult. A dispersing agent can be appropriately used for the dispersion. The addition amount of the dispersant is preferably 0.01 to 5% by mass, and more preferably 0.1 to 2% by mass with respect to the composite metal oxide particles.

  The addition amount of these composite metal oxides is 20% or more and less than 40%, more preferably 25% or more and less than 39%, more preferably 25% or more and less than 30%, based on the total solid content of the hydrophilic layer. Range. When the addition amount is less than 20%, sufficient sensitivity cannot be obtained, and when it is 40% or more, ablation residue due to ablation occurs.

  In the present invention, the following infrared absorbing dye can be added as a photothermal conversion material to the hydrophilic layer and the image forming layer.

  General infrared absorbing dyes such as cyanine dyes, croconium dyes, polymethine dyes, azurenium dyes, squalium dyes, thiopyrylium dyes, naphthoquinone dyes, anthraquinone dyes, organic compounds such as phthalocyanine dyes and naphthalocyanine dyes , Azo-based, thioamide-based, dithiol-based, and indoaniline-based organometallic complexes. Specifically, JP-A-63-139191, JP-A-64-33547, JP-A-1-160683, JP-A-1-280750, JP-A-1-293342, JP-A-2-2074, Kaihei 3-26593, JP-A-3-30991, JP-A-3-34891, JP-A-3-36093, JP-A-3-36094, JP-A-3-36095, JP-A-3-42281, JP-A-3-42281 Examples thereof include compounds described in JP-A-3-97589, JP-A-3-103476, and the like. These can be used alone or in combination of two or more.

  The addition amount of these infrared absorbing dyes is 0.1% or more and less than 10%, more preferably 0.3% or more and less than 7%, more preferably 0.5%, based on the total solid content of the image forming layer. The range is less than 6%. If the addition amount deviates from this, as described above, if the addition amount is less than 0.1%, sufficient sensitivity cannot be obtained, and if it is 10% or more, ablation residue due to ablation occurs.

  In the present invention, it is preferable to have at least one backing layer on the opposite side of the image forming functional layer of the support in order to handle and prevent physical property changes during storage. The backing layer preferably contains a hydrophilic binder, and particularly if the printing plate material surface is hydrophobic, the water dispersion described in paragraphs 0033 to 0038 of JP-A-2002-258469 It may be obtained from a base resin (polymer latex).

  The hydrophilic binder is not particularly limited as long as it is hydrophilic. Polyvinyl alcohol (PVA), which is a resin having a hydroxyl group as a hydrophilic structural unit, a cellulose resin (methyl cellulose (MC), ethyl cellulose (EC), Hydroxyethylcellulose (HEC), carboxymethylcellulose (CMC), etc.), chitins, and starch; polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE) which are resins having an ether bond And polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP), which are resins having an amide group or an amide bond. In addition, polyacrylates, maleic resins, alginates and gelatins having carboxyl groups as dissociable groups; polystyrene sulfonates having sulfone groups; amino groups, imino groups, tertiary amines and quaternary ammonium salts Examples thereof include polyallylamine (PAA), polyethyleneimine (PEI), epoxidized polyamide (EPAm), polyvinylpyridine, and gelatins.

  The hydrophobic binder is not particularly limited as long as it is hydrophobic as a binder. For example, polymers derived from α, β-ethylenically unsaturated compounds such as polyvinyl chloride, post-chlorinated polyvinyl chloride, and vinyl chloride are used. Copolymers of vinylidene chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and partially hydrolyzed polyvinyl acetate, starting from polyvinyl alcohol, and only a portion of the repeating vinyl alcohol units react with the aldehyde. And polyvinyl acetals, preferably polyvinyl butyral, copolymers of acrylonitrile and acrylamide, polyacrylates, polymethacrylates, polystyrene and polyethylene or mixtures thereof.

In the present invention, it is necessary to contain a matting agent in the back coating layer in order to prevent the color misalignment in color printing due to the ease of attachment to the printing press and the misalignment of the printing plate during printing. The matting agent to be contained may be used regardless of porous, nonporous, organic resin particles, and inorganic fine particles. Examples of the inorganic matting agent include silica, alumina, zirconia, titania, carbon black, graphite, TiO ₂ , BaSO ₄ , ZnS, MgCO ₃ , CaCO ₃ , ZnO, CaO, WS ₂ , MoS ₂ , MgO, SnO ₂ , Al ₂ O ₃ , α-Fe ₂ O ₃ , α-FeOOH, SiC, CeO ₂ , BN, SiN, MoC, BC, WC, titanium carbide, corundum, artificial diamond, garnet, garnet, silica, triboli, diatomaceous earth, dolomite, etc. As organic matting agents, polyethylene fine particles, fluororesin particles, guanamine resin particles, acrylic resin particles, silicone resin Examples thereof include particles and melamine resin particles. Examples of the inorganic clothing matting agent include particles in which a core agent of organic particles such as PMMA, polystyrene, and melamine is coated with inorganic particles that are smaller than the core agent particles. The particle size of the inorganic particles is preferably about 1/10 to 1/100 of the core particles. As the inorganic particles, similarly known metal oxide particles such as silica, alumina, titania, zirconia can be used. As the coating method, various known methods can be used, but the core material particles and the coating material particles are collided at high speed in the air like a hybridizer to cause the coating material particles to bite into the surface of the core material particles. A dry coating method of fixing and coating can be preferably used.

In the present invention, the matting agent satisfying the scope of the present invention can exert the effect without any particular limitation. However, particularly in the case of a product form wound in a roll shape, the matting agent of the back coating layer is an image forming layer. In order to suppress scratches on the surface, it is preferable to use organic resin particles.
The average particle size of the matting agent in the present invention can be obtained by calculating an equivalent circle light from the projected area using an electron microscope.

  The particle size is preferably 1 to 12 μm, more preferably 1.5 to 8 μm, and even more preferably 2 to 7 μm. When the particle diameter exceeds 12 μm, scratches on the image forming layer are likely to occur, and conversely, with 1 μm particles, plate lifting occurs on the plate cylinder.

  The addition amount of the matting agent is preferably 0.2 to 30% by mass, and more preferably 1 to 10% by mass based on the entire back coating layer.

  Furthermore, the laser recording apparatus or the processless printing machine has a sensor for controlling the conveyance of the printing plate inside the apparatus, and in order to perform these controls without delay, Preferably contains a dye and a pigment. As the dye and the pigment, an infrared absorbing dye and a black pigment such as carbon black used for the above-described photothermal conversion material are preferably used. Further, the constituent layer may contain a known surfactant.

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

(Production of support)
(PET resin)
0.05 parts by mass of magnesium acetate hydrate was added as a transesterification catalyst to 100 parts by mass of dimethyl terephthalate and 65 parts by mass of ethylene glycol, and transesterification was performed according to a conventional method. To the obtained product, 0.05 part by mass of antimony trioxide and 0.03 part by mass of trimethyl phosphate were added. Subsequently, the temperature was gradually raised and the pressure was reduced, and polymerization was carried out at 280 ° C. and 66.67 Pa to obtain a polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.70.

  Using the PET resin obtained as described above, a biaxially stretched PET film was prepared as follows.

(Biaxially stretched PET film)
Pelletized PET resin was vacuum-dried at 150 ° C for 8 hours, melted and extruded from a T-die at 285 ° C in a layered form, closely contacted with electrostatic application on a 30 ° C cooling drum, cooled and solidified, and unstretched A film was obtained. This unstretched sheet was stretched 3.3 times in the longitudinal direction at 80 ° C. using a roll-type longitudinal stretching machine. Subsequently to the obtained uniaxially stretched film, the film was stretched by 50% of the total transverse stretching ratio at 90 ° C. in the first stretching zone and further at a total stretching ratio of 3.3 at 100 ° C. in the second stretching zone. Stretched to double. Subsequently, pre-heat treatment was performed at 70 ° C. for 2 seconds, and heat setting was further performed at the first fixing zone 150 ° C. for 5 seconds, and heat setting was performed at the second fixing zone 220 ° C. for 15 seconds. Next, it was relaxed 5% in the transverse (width) direction at 160 ° C., and after exiting the tenter, it was cooled to room temperature over 60 seconds, the film was released from the clip, slitted, wound up, and wound at a thickness of 175 μm. An axially stretched PET film was obtained. The biaxially stretched PET film had a Tg of 79 ° C. The thickness distribution of the obtained support was 2%.

On the image forming functional layer of the biaxially stretched PET film, the surface is subjected to a corona discharge treatment of 8 W / m ² · min, and the undercoat coating liquid a-1 is applied to a dry film thickness of 0.8 μm, and 123 ° C. And undercoat layer A-1 was provided on the hydrophilic side.

The opposite surface and surface were subjected to a corona discharge treatment of 8 W / m ² · min, and the undercoat coating solution b-1 was used as an undercoat undercoat layer at 23 ° C. so that the dry film thickness was 0.1 μm. And an undercoat layer B-1 having an antistatic function was provided.

Thereafter, the upper surface of the undercoat layers A-1 and B-1 is subjected to a corona discharge treatment of 8 W / m ² · min, and the undercoat coating solution a-2 is dried on the undercoat layer A-1. The coating is applied to a thickness of 0.1 μm and dried at 123 ° C. to provide an undercoat layer A-2. On the undercoat layer B-1, the undercoat coating solution b-2 is dried. The sample was applied to a thickness of 0.2 μm, dried at 123 ° C. to provide an undercoat layer B-2, and further heat-treated at 123 ° C. for 2 minutes to obtain a sample 11 with an undercoat layer formed.

  For sample 11, undercoat layer A-1 (styrene-butadiene latex of coating solution a-1) and undercoat layer A-2 (modified aqueous polyester Lx-3 of coating solution a-2) have the compositions shown in Table 5. Samples 12 to 20 were changed. Further, as a comparison, the samples 1 to 3 without the undercoat layer A-1 and the undercoat layer A-2 and the undercoat layer A-2 (the coating liquid a-2) without the undercoat layer A-1 were prepared. Samples 4 to 6 were produced in which the modified aqueous polyester Lx-3) was changed to the composition shown in Table 5.

(Undercoating liquid a-1)
Styrene-butadiene latex (Nippol LX432A Nippon Zeon)
Solid content 30% 55g
Anionic surfactant S-1 (2%) 30 g
Finished to 1 kg with water.

Tin oxide sol (8.3%) 109.5g
Styrene / butyl acrylate / hydroxy methacrylate = 27/45/28 ternary copolymer latex (Tg = 45 ° C.) Solid content concentration 30% 3.8 g
Styrene / glycidyl methacrylate / butyl acrylate = 60/39/1 ternary copolymer latex (Tg = 75 ° C.) Solid content concentration 30% 15 g
Anionic surfactant S-1 (2%) 30 g
Distilled water was added to make 1 kg.

(Undercoating liquid a-2)
Modified aqueous polyester Lx-3 solution (18% by mass) 150 g
Anionic surfactant S-1 (2%) 6g
Spherical silica matting agent (Nippon Shokubai Sea Hoster KE-P50) 2% dispersion 10g
Distilled water was added to make 1000 ml.

(Undercoating liquid b-2)
Modified aqueous polyester Lx-3 solution (18% by mass) 150 g
Anionic surfactant S-1 (2%) 6g
Spherical silica matting agent (Nippon Shokubai Sea Hoster KE-P50) 2% dispersion 10g
Distilled water was added to make 1000 ml.

(Preparation of aqueous polyester solution)
35.4 parts by weight of dimethyl terephthalate, 33.63 parts by weight of dimethyl isophthalate, 17.92 parts by weight of dimethyl sodium 5-sulfoisophthalate, 62 parts by weight of ethylene glycol, 0.065 parts by weight of calcium acetate monohydrate, acetic acid After 0.02 parts by mass of manganese tetrahydrate was subjected to a transesterification reaction while distilling off methanol at 170 to 220 ° C. under a nitrogen stream, 0.04 parts by mass of trimethyl phosphate and antimony trioxide as a polycondensation catalyst 0.04 parts by mass and 6.8 parts by mass of 1,4-cyclohexanedicarboxylic acid were added, and an approximately theoretical amount of water was distilled off at a reaction temperature of 220 to 235 ° C. for esterification. Thereafter, the reaction system was further depressurized and heated for about 1 hour, and finally subjected to polycondensation at 280 ° C. and 133 Pa or less for about 1 hour to prepare an aqueous polyester A-1. The obtained aqueous polyester A-1 had an intrinsic viscosity of 0.33.

  Next, 850 ml of pure water was put into a 2 L three-necked flask with a stirring blade, a reflux condenser, and a thermometer, and 150 g of aqueous polyester A-1 was gradually added while rotating the stirring blade. The mixture was stirred at room temperature for 30 minutes, heated to an internal temperature of 98 ° C. over 1.5 hours, and heated and dissolved at this temperature for 3 hours. After completion of the heating, the mixture was cooled to room temperature over 1 hour and allowed to stand overnight to produce a 15% by mass aqueous polyester.

(Preparation of Modified Polyester Lx-3 Solution)
Into a 3 L four-necked flask with a stirring blade, a reflux condenser, a thermometer, and a dropping funnel, 1900 ml of the 15% by weight aqueous polyester solution is placed and heated so that the internal temperature becomes 80 ° C. while rotating the stirring blade. . To this, 6.52 ml of a 24% aqueous solution of ammonium peroxide is added, and a monomer mixture (ethyl acrylate 35.7 g, methyl methacrylate 35.7 g) is added dropwise over 30 minutes, and the reaction is continued for another 3 hours. Then, it cooled and filtered to 30 degrees C or less, and prepared the modified aqueous polyester Lx-3 solution whose solid content concentration is 18 mass%.

  Preparation of the back coating layer

  The composition shown in Table 1 was sufficiently stirred and mixed using a homogenizer, and then filtered to prepare a back coating layer coating solution.

Application of back coating layer The coating liquid of the back coating layer was applied to the undercoated samples 001 to 008 on the support undercoating surface B side using the wire bar # 6, and set to 100 ° C. with a length of 15 m. The dried zone was passed at a conveying speed of 15 m / min. The amount of the back coating layer was 2.0 g / m ² .

  Preparation of lower hydrophilic layer coating solution

  The composition shown in Table 2 was sufficiently stirred and mixed using a homogenizer and then filtered to prepare a lower hydrophilic layer coating solution.

  Preparation of upper hydrophilic layer coating solution

  The composition shown in Table 3 was sufficiently stirred and mixed using a homogenizer and then filtered to prepare an upper hydrophilic layer coating solution.

Application of lower layer and upper layer hydrophilic layer The above lower layer hydrophilic layer coating solution was applied to the back surface (undercoating surface A) of the support coated with the above back coat layer using a wire bar # 5, and the length was 15 m. The drying zone set at 100 ° C. was passed at a conveying speed of 15 m / min. Subsequently, the upper hydrophilic layer coating solution was applied using wire bar # 3 and passed through a drying zone set at 100 ° C. having a length of 30 m at a conveyance speed of 15 m / min. The amount of each of the lower layer and the hydrophilic layer was 3.0 g / m ² and 0.55 g / m ² . The sample after coating was aged at 60 ° C. for 1 day.

Preparation of coating solution for image forming layer An image layer having the composition shown in Table 4 below was applied on the upper hydrophilic layer prepared above using wire bar # 5, and the drying was set to 70 ° C. with a length of 30 m. The zone was passed at a conveying speed of 15 m / min to form an image forming layer. The amount of the image forming layer applied was 0.5 g / m ² . The coated sample was aged at 50 ° C. for 2 days to prepare a lithographic printing plate material.

  The lithographic printing plate material was cut into a width of 660 mm and wound around a paper core having an outer diameter of 76 mm by 30 m to obtain rolled lithographic printing plate materials 1 to 6 and 11 to 20.

Printing method Using DAIYAF-1 manufactured by Mitsubishi Heavy Industries, Ltd. as a printing device, coated paper, dampening water astromark 3 (manufactured by Nikken Chemical Research Co., Ltd.), 2% by mass, and two types of ink are prepared. Printing evaluation was performed.
(1): Toyo King High Echo M Red (Toyo Ink Co., Ltd.)
(2): TM Hi-Echo SOY1 (Toyo Ink Soybean Oil Ink)
Evaluation of printing (waste paper)
Good S / N ratio at the time of printing (the non-image portion is free of background stain, that is, the non-image portion of the image forming layer is removed on the printing machine, and the density of the image portion is within an appropriate range. In particular, the number of printed sheets until a printed matter having a development defect due to scratches on the image layer due to the mat material of the backcoat layer was obtained was evaluated. The smaller the number of waste paper, the better. There are practical problems with 40 sheets or more.

Evaluation of printing durability When either a 3% dot missing in the image or a decrease in the density of the solid portion was confirmed, the printing printing end point was determined and the number of sheets was determined.

  As is apparent from Table 5, the lithographic printing plate material of the present invention has printing performance excellent in on-press development property and printing durability.

Claims (9)

A plastic support for a lithographic printing plate material, comprising an undercoat layer containing a styrene-diolefin copolymer on at least one surface of the plastic support. Two undercoat layers, an undercoat layer adjacent to the support contains a styrene-diolefin copolymer, and an undercoat upper layer is gelatin, a water-based polymer containing a polyvinyl alcohol unit, polyester, vinyl type The plastic support for a lithographic printing plate material according to claim 1, comprising at least one of polymers. 3. The plastic support for a lithographic printing plate material according to claim 1, wherein corona discharge, glow discharge, or plasma treatment is applied before applying the undercoat layer. The hydrophilic layer containing the inorganic hydrophilic compound obtained by sol-gel conversion on the surface side provided with the undercoat layer of the plastic support for the lithographic printing plate material according to any one of claims 1 to 3 A lithographic printing plate material comprising: The lithographic printing plate material according to claim 4, further comprising an image-forming functional layer containing heat-meltable fine particles or heat-fusible fine particles on the hydrophilic layer side. The lithographic printing plate material according to claim 4 or 5, wherein the hydrophilic layer or the image forming functional layer contains a photothermal conversion material. The lithographic printing plate material according to any one of claims 4 to 6, wherein the image forming functional layer is an on-press developable layer. The lithographic printing plate material according to any one of claims 4 to 7, wherein the lithographic printing plate material is in the form of a roll. An image is formed on the lithographic printing plate material according to any one of claims 4 to 8 using a thermal head or a thermal laser, and then development is performed with a fountain solution or a fountain solution and printing ink on the lithographic printing machine. A printing method characterized by performing and printing.