JP2006088354A - Printing plate material, printing plate and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing plate material with excellent conveyability inside a platemaking device and also excellent printability, and a printing plate using this printing plate material and a printing method. <P>SOLUTION: The printing plate material has an imaging function layer formed on one of the surfaces of a polyester support and a conductive layer containing a conductive material formed on the other surface. The conductive material is a tin oxide and has a back coat layer formed on the conductive layer. In addition, the conductive layer and the back coat layer each contains a polyester resin, an acrylic resin, or a cellulose ester resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing plate material having a polyester support, a printing plate using the same, and a printing method.

  In recent years, CTP systems that record digital image data directly on a printing plate material with a laser light source have become widespread in a technique for producing a printing plate for offset printing. The printing plate material used for the CTP system includes a type using an aluminum substrate as in the conventional PS plate and a flexible type having a functional layer as a printing plate on a film substrate. In recent years, in commercial printing, there has been a tendency to reduce the number of various types of printing, and there is a strong demand for high-quality and low-cost printing plate materials in the market. In such markets, flexible type printing plate materials are often used. ing.

  As a flexible type printing plate material, for example, a film base as disclosed in JP-A-5-66564 is provided with a silver salt diffusion transfer type photosensitive layer, or JP-A-8-507727 and JP-A-6. -186750, 6-199064, 7-314934, 10-58636, 10-244773 as disclosed in any one of a hydrophilic layer and a lipophilic layer on a film substrate. A layer is laminated as a surface layer, and the surface layer is ablated by laser exposure to form a printing plate, or a hydrophilic layer and a heat-meltable image forming layer are provided on a film substrate, and hydrophilicity is obtained by laser exposure. For example, the image forming layer may be melt-fixed on the hydrophilic layer by causing the heat generating layer or the image forming layer to generate heat like an image (see, for example, Patent Document 1).

  The silver salt diffusion transfer method requires a wet development and drying process after exposure, and dimensional accuracy in the image forming process cannot be obtained sufficiently, so it cannot be said that it is optimal for high-quality printing.

  The ablation method does not require development processing, but the dot shape tends to become unstable because an image is formed by ablation of the surface layer. Further, contamination of the material surface and the inside of the exposure apparatus due to the ablated surface layer scattering may occur.

  Further, a material of a system that converts laser light into heat and forms a heat-melted image on a hydrophilic layer can obtain a sharp dot shape and is suitable for high-definition image formation.

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 area is dampened 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 printing stage. (See Patent Document 2 and Patent Document 3.)
A flexible type printing plate material in which the laser beam is converted into heat and the image forming layer is melted and fixed on the hydrophilic layer is advantageously used in this process.

  In such a printing plate material, a sharp dot shape and a high-definition image are obtained, a development process after exposure is not required, and the quality stability and environmental suitability are excellent.

  However, such printing plate materials have problems such as insufficient transportability in the plate making apparatus and printing apparatus, and the image forming layer is easily damaged.

  In order to improve these points, for example, a printing plate material provided with a roughened layer or a conductive layer on the back surface is known (see Patent Document 4).

However, even with such printing plate materials, the transportability is still inadequate, the layer provided on the back side may be peeled off, the mounting property to the plate cylinder at the time of printing may be poor, and the printability is insufficient. There were some problems.
JP 2001-96710 A JP-A-9-123387 JP-A-9-123388 JP 2004-34394 A

  An object of the present invention is to provide a printing plate material having excellent transportability in a plate making apparatus and excellent printability, a printing plate using the same, and a printing method.

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

(Claim 1)
In a printing plate material having an image forming functional layer on one side of a polyester support and a conductive layer containing a conductive substance on the other side, the conductive substance is tin oxide, A printing plate material comprising: a backcoat layer; and the conductive layer and the backcoat layer each contain a polyester resin, an acrylic resin, or a cellulose ester resin.

(Claim 2)
The printing plate material according to claim 1, wherein the image forming functional layer is a layer that can be developed on a printing press.

(Claim 3)
The printing plate material according to claim 1 or 2, wherein the image-forming functional layer contains heat-fusible particles or heat-fusible particles.

(Claim 4)
The printing plate material according to any one of claims 1 to 3, further comprising a layer containing a photothermal conversion material on a side having the image forming functional layer.

(Claim 5)
A printing plate obtained by developing the printing plate material according to any one of claims 1 to 4 on a printing press after image exposure with a laser beam.

(Claim 6)
A printing method using the printing plate according to claim 5.

  According to the above configuration of the present invention, a printing plate material excellent in transportability in a plate making apparatus, excellent in adhesion of a layer provided on the back surface, and excellent in mounting property to a plate cylinder of a printing machine, and the use thereof are used. Printing plates and printing methods can be provided.

  The present invention provides a printing plate material having an image forming functional layer on one side of a polyester support and a conductive layer containing a conductive substance on the other side, wherein the conductive substance is tin oxide, A back coat layer is provided on the conductive layer, and each of the conductive layer and the back coat layer contains a polyester resin, an acrylic resin, or a cellulose ester resin.

  The present invention has a conductive layer containing tin oxide on the back surface of a printing plate material, and the above-mentioned specific resin as a binder is contained in the conductive layer and the back coat layer thereon, thereby forming an image forming functional layer. It is possible to provide a printing plate material that is excellent in preventing scratches, is excellent in transportability in a plate making apparatus, and is excellent in the ability to be mounted on a printing drum, and a printing plate and a printing method using the same.

(Conductive layer)
The conductive layer according to the present invention refers to the surface specific resistance value (immediately after being left for 24 hours at 23 ° C. and 20% relative humidity) of the surface of the printing plate material on the side of the conductive layer 1 × 10 ⁷ Ω to 1 × 10 ^The layer can be ¹³ Ω and contains tin oxide as a conductive material.

  Here, “immediately after being left at 23 ° C. and 20% relative humidity for 24 hours” means, for example, that a printing plate material is left in a room conditioned at 23 ° C. and 20% relative humidity for 24 hours, and immediately after this is left in the room. In this case, the measurement is performed with a device for measuring the surface specific resistance (for example, Teraohm Meter Model VE-30 manufactured by Kawaguchi Electric Co., Ltd.).

  The tin oxide according to the present invention is preferably used 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.

The amorphous SnO ₂ sol that can be used in the present invention can be produced by dispersing SnO ₂ fine particles in a suitable solvent or by decomposing a soluble Sn compound in a solvent. And the like.

  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 , (CH ₃ ) ₃ SnCl. (Pyridine), ( Examples thereof include organometallic compounds such as C ₄ H ₉ ) ₂ Sn (O ₂ CC ₂ H ₅ ) ₂ and oxo salts such as Sn (SO ₄ ) ₂ .2H ₂ O.

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 a specific production method, for example, SnCl ₄ is dissolved in 100 times volume of distilled water to form a precipitate of Sn (OH) ₄ as an intermediate, and ammonia water is added thereto to make it slightly alkaline, and then ammonia. When heated until the odor disappears, a colloidal SnO ₂ sol is obtained. Instead of water as the above solvent, 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 aromatic organic solvents such as benzene and pyridine It is possible to use various solvents depending on the Sn compound.

  On the other hand, the crystalline particles can be obtained by the method described in detail in JP-A-56-143430 and JP-A-60-258541.

  The average particle diameter of the tin oxide according to the present invention (the average value of the primary particle diameter (represented by the diameter when the projected area of the particle is converted into a circle)) is 0.001 to 0.5 μm, particularly 0.001 to 0.00. 2 μm is preferred.

The solid amount of tin oxide used in the present invention is preferably 0.05 to ² g, more preferably 0.1 to 1 g, per 1 m ² .

  Further, the volume fraction of tin oxide in the conductive layer according to the present invention is preferably 8 to 40 vol%, particularly preferably 10 to 35 vol%, from the viewpoint of conductivity and adhesiveness.

  The conductive layer according to the present invention includes other conductive materials such as soluble salts (for example, chlorides, nitrates, etc.), insoluble inorganic salts as described in US Pat. No. 3,428,451, metals Oxides, conductive materials such as conductive polymers as described in US Pat. Nos. 2,861,056 and 3,206,312 may also be included.

(Polyester resin, acrylic resin, cellulose ester resin)
The conductive layer of the present invention contains a polyester resin, an acrylic resin or a cellulose ester resin as a binder.
(Polyester resin)
The polyester resin according to the present invention refers to a substantially linear resin obtained by polycondensation reaction between a polybasic acid or an ester thereof and a polyol or an ester thereof, and a resin obtained by modifying the resin.

  Examples of the polybasic acid component 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.

  As the polyester resin according to the present invention, a hydrophilic polyester resin is preferably used.

  For the hydrophilic polyester resin, a dicarboxylic acid having a sulfonate salt as a polybasic acid component is preferable. For example, those having an alkali metal sulfonate group, specifically 4-sulfoisophthalic acid, 5-sulfoisophthalic acid, Alkali metal salts such as sulfoterephthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5- (4-sulfophenoxy) isophthalic acid can be used. Among these, 5-sulfoisophthalic acid sodium salt 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.

  Further, as the hydrophilic polyester resin, those having terephthalic acid and isophthalic acid as main dicarboxylic acid components are also preferable, and the ratio of terephthalic acid and isophthalic acid to be used is 30/70 to 70/30 in molar ratio. It is particularly preferable from the viewpoint of applicability to a polyester support 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 other than the above 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, trimethylolpropane, Poly (ethylene oxide) glycol and poly (tetramethylene oxide) glycol can be used.

  As these glycol components, it is preferable to use those having ethylene glycol of 50 mol% or more of the total glycol components.

  The polyester resin can be synthesized using dicarboxylic acid or its ester and glycol or its ester 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.

  As the polyester resin according to the present invention, an acrylic modified polyester resin can also be preferably used, and in particular, a hydrophilic polyester resin modified with acrylic is preferably used.

  A hydrophilic polyester resin modified with acrylic is obtained by dispersing and polymerizing an acrylic resin in an aqueous solution in which a hydrophilic polyester is present. A dispersion is obtained by, for example, dissolving a hydrophilic polyester in hot water. It can be obtained by dispersing an acrylic resin in an aqueous solution of an aqueous polyester resin and subjecting it to emulsion polymerization or suspension polymerization. The polymerization is preferably by emulsion polymerization.

  Examples of the polymerization initiator 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.

  Examples of the acrylic monomer used in the acrylic modified hydrophilic polyester resin include 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-dimethylo Amide group-containing monomers such as ruacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide and N-phenylacrylamide; amino group-containing monomers such as N, N-diethylaminoethyl acrylate and N, N-diethylaminoethyl methacrylate; glycidyl Examples thereof include epoxy group-containing monomers such as acrylate and glycidyl methacrylate; monomers containing a carboxyl group such as acrylic acid, methacrylic acid and salts thereof (sodium salt, potassium salt, ammonium salt, etc.) or salts thereof.

  The amount of acrylic resin used for modification is preferably (hydrophilic polyester resin) / (acrylic resin) in the range of 99/1 to 5/95 by mass ratio, and in the range of 97/3 to 50/50. More preferably, it is in the range of 95/5 to 80/20.

(acrylic resin)
The acrylic resin according to the present invention is a polymer of acrylic acid and its derivatives or a copolymer containing these as a main component.

  As acrylic acid and its derivatives, the above acrylic monomers can be used.

  It is environmentally preferable that the acrylic resin according to the present invention is an acrylic polymer latex in the form of a polymer latex.

  The acrylic 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.

  Examples of the polymer latex that can be used in the present invention include “synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Kobunshi Publishing Co., Ltd. (1978))”, “application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Kasahara) Keiji, published by Kobunshi Kyokukai (1993)), “Synthetic Latex Chemistry (Souichi Muroi, published by Kobunshi Kyokukai (1970))” and the like.

  The average particle size of the dispersed particles of the acrylic polymer latex is preferably in the range of 1 to 50000 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 acrylic polymer latex 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 acrylic polymer latex 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.

(Cellulose ester resin)
The cellulose ester resin according to the present invention refers to a compound in which part or all of the hydroxyl groups of cellulose are esterified.

  As the cellulose ester resin, for example, cellulose nitrate, cellulose acetate, cellulose acetate putionate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate and the like can be used, but cellulose acetate butyrate and cellulose acetate pro Pionate is preferred.

  A cellulose ester resin containing a hydroxyl group can also be preferably used as the cellulose ester resin.

  In the conductive layer according to the present invention, a polyester resin, an acrylic resin, or a cellulose ester resin may be used alone as a binder, or a mixture of these two or three kinds may be used.

  The content of these resins in the conductive layer is preferably 50% by mass to 95% by mass.

  Further, the conductive layer may contain a crosslinkable resin such as amino resin, phenol resin, epoxy resin, polyisocyanate or other resin as a binder.

  The film thickness of the conductive layer according to the present invention is preferably from 0.3 μm to 1.0 μm, and particularly preferably from 0.35 μm to 0.8 μm, from the viewpoint of scratch resistance of the image forming layer.

  The drying conditions for providing the conductive layer according to the present invention are preferably less than Tg + 15 ° C. of the polyester film from the viewpoint of preventing deformation of the support.

  In the present invention, it is preferable to provide an undercoat layer before providing the conductive layer. In particular, it is preferable to apply the coating solution on one or both sides of the polyester film before the completion of crystal orientation in terms of improving the coating property when applying the antistatic layer, and it is possible to prevent scratches and the like during the heat treatment. This is preferable.

  As a coating method of the conductive 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.

(Back coat layer)
The backcoat layer according to the present invention is a layer provided on the conductive layer, and contains a polyester resin, an acrylic resin, or a cellulose ester resin.

  The layer provided on the conductive layer is a layer located farther from the conductive layer with the support as a base point.

  The polyester resin, acrylic resin, and cellulose ester resin can be the same as described above.

  The content of the polyester resin, acrylic resin or cellulose ester resin in the back coat layer is preferably 20% by mass to 80% by mass, and particularly preferably 30% by mass to 70% by mass.

  The back coat layer of the present invention preferably contains a matting agent.

As the matting agent, 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, quartzite, triboli, diatomaceous earth, dolomite And inorganic matting agents such as polyethylene fine particles, fluororesin particles, guanamine resin particles, acrylic resin particles, silicon resin particles, and melamine resin particles.

  A composite matting agent containing an inorganic matting agent and an organic matting agent can also be used.

  The average particle size of the matting agent used for the back coat layer is preferably 1 to 12 μm, more preferably 1.5 to 8 μm, and further preferably 2 to 7 μm.

  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 coat layer.

(Polyester support)
The polyester used for the polyester support is not particularly limited, and is mainly composed of a dicarboxylic acid component and a diol component. For example, polyethylene terephthalate (hereinafter sometimes referred to as PET for short) Polyester such as polyethylene naphthalate (hereinafter sometimes abbreviated as PEN).

  Preferably, PET or a copolymer or blended polyester having a part composed of PET as a main component and having a mass ratio of components constituting the entire polyester of 50% by mass or more.

  PET is polymerized with terephthalic acid and ethylene glycol, and PEN polymerized with naphthalenedicarboxylic acid and ethylene glycol as constituent components.

  The dicarboxylic acid or diol constituting PET or PEN may be polymerized by mixing other appropriate one type or two or more third components. A suitable third component is a compound having a divalent ester-forming functional group. Examples of the dicarboxylic acid include the following. Terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenylether dicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, diphenyldicarboxylic acid, diphenylthioether dicarboxylic acid Examples thereof include acid, diphenyl ketone dicarboxylic acid, and phenylindane dicarboxylic acid.

  Examples of glycols include propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, and bis (4- Hydroxyphenyl) sulfone, bisphenol full orange hydroxyethyl ether, diethylene glycol, neopentyl glycol, hydroquinone, cyclohexanediol and the like. As the third component, a polyfunctional carboxylic acid or a polyhydric alcohol can also be mixed, but these can be mixed in an amount of about 0.001 to 5% by mass with respect to all the polyester components.

  The intrinsic viscosity of the polyester is preferably 0.5 to 0.8. Moreover, you may mix and use what has a different intrinsic viscosity.

  The method for polymerizing the polyester is not particularly limited, and can be produced according to a conventionally known polyester polymerization method. For example, a direct ester is obtained by directly esterifying a dicarboxylic acid component with a diol component, diesterifying one hydroxyl group of the diol to a dicarboxylic acid, and heating the other diol under reduced pressure to distill off the excess diol. A dialkyl ester (for example, dimethyl ester) as a dicarboxylic acid component, and a transesterification reaction between this and a diol component to distill alkyl alcohol (for example, methanol) to distill one hydroxyl group of the diol to a dicarboxylic acid. It is possible to use a transesterification method in which polymerization is performed by esterification into an acid and further heating and distilling off excess diol components under reduced pressure.

As the catalyst, a transesterification catalyst, a polymerization reaction catalyst, and a heat stabilizer used for synthesis of a normal polyester can be used. For example, examples of transesterification catalysts include Ca (OAc) ₂ .H ₂ O, Zn (OAc) ₂ .2H ₂ O, Mn (OAc) ₂ .4H ₂ O, Mg (OAc) ₂ .4H ₂ O, and the like. Examples of the polymerization reaction catalyst include Sb ₂ O ₃ and GeO ₂ . Examples of the heat stabilizer include phosphoric acid, phosphorous acid, PO (OH) (CH ₃ ) ₃ , PO (OC ₆ H ₅ ) ₃ , P (OC ₆ H ₅ ) _{3 and the} like. In addition, anti-coloring agent, crystal nucleating agent, slip agent, stabilizer, anti-blocking agent, UV absorber, viscosity modifier, clearing agent, antistatic agent, pH adjuster, dye, pigment, etc. May be added.

  The thickness of the polyester support is preferably 100 to 250 μm, particularly preferably 150 to 200 μm from the viewpoint of ease of handling.

(Applying undercoat layer to support)
The polyester support according to the present invention can be subjected to easy contact treatment or undercoat layer coating in order to have various functions.

  Examples of the easy adhesion treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment.

  As the undercoat layer, a layer containing gelatin or latex is preferably provided on the support.

  In addition, a polyester film is used as the polyester support according to the present invention, and a material such as a polyester film and a metal plate (for example, iron, stainless steel, aluminum) or paper coated with polyethylene (also referred to as a composite substrate). It is also possible to use a composite support obtained by laminating as appropriate.

  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.

(Image forming functional layer)
The image forming functional layer according to the present invention is a layer capable of forming a printable image by image exposure, and preferably, Japanese Patent Application Laid-Open No. 8-507727 or Japanese Patent Application Laid-Open No. 6-186750 which is recorded by thermal laser recording or thermal head recording. Used in printing plate materials of the ablation type as described in JP-A-9-123, and the development type on the thermal fusion image layer machine and the thermal fusion transfer type as described in JP-A-9-123387.

  Among these, layers that can be developed on a printing press that do not require a developer treatment with a special chemical, so-called processless CTP printing plate, ablation type, thermal fusion image layer development type, thermal melt transfer type, and phase conversion type The effect of the present invention is great when the image forming functional layer used in the printing plate material is aluminum.

  The layer developable on a printing press is a layer capable of forming a printable image by dampening water in lithographic printing or dampening water and printing ink.

  The image forming functional layer according to the present invention is preferably an image forming functional layer containing heat-meltable particles or heat-fusible particles, and further preferably contains a water-soluble binder.

(Hot-melting particles)
The heat-meltable particles that can be preferably used in the image-forming functional layer according to the present invention are particles formed of a material that is low in 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, in view of storage stability and ink inking property, 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. More preferably, it is not higher than ° C.

  Examples of materials that can be used include paraffin, polyolefin, polyethylene wax, microcrystalline wax, and fatty acid wax. These have a molecular weight of about 800 to 10,000, and in order to facilitate emulsification, these waxes can be oxidized to introduce polar groups such as a hydroxyl group, an ester group, a carboxyl group, an aldehyde group, and a peroxide group. Furthermore, in order to lower the softening point and improve workability, these waxes are used, for example, stearamide, linolenamide, laurylamide, myristamide, hardened bovine fatty acid amide, palmitoamide, oleic acid amide, rice sugar fatty acid amide. It is also possible to add coconut fatty acid amides or methylolated products of these fatty acid amides, methylene bisstellaramide, ethylene bisstellaramide and the like. 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, and fatty acid. Since these materials have a relatively low melting point and a low melt viscosity, high-sensitivity image formation can be performed. Further, 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.

  These heat-meltable particles are preferably dispersible in water, and the average particle diameter is preferably 0.01 to 10 μm, more preferably 0.05 to 3 μm from the viewpoint of on-press developability. .

  When the average particle size of the heat-meltable particles is larger than 10 μm, the resolution is lowered. In the case of containing two or more kinds of heat-meltable fine particles, the average particle diameter is preferably separated from each other by 0.1 μm or more.

  In order to disperse these heat-meltable particles in water, it is preferable to use a nonionic surfactant, an anionic surfactant, a cationic surfactant, or a polymer surfactant. By using these compounds, it is possible to stabilize an aqueous dispersion of heat-meltable fine particles, and to obtain a uniform coated product having no failure.

  Preferable examples of the nonionic surfactant include the following. Alkyl polyoxyethylene ether, alkyl polyoxyethylene, polyoxypropylene ether, fatty acid polyoxyethylene ester, fatty acid polyoxyethylene sorbitan ester, fatty acid polyoxyethylene sorbitol ester, polyoxyethylene castor oil, polyoxyethylene adduct of acetylene glycol, Polyoxyethylene adducts such as alkyl polyoxyethylene amines and amides; polyhydric alcohols and alkylol amides such as fatty acid sorbitan esters, fatty acid polyglycerin esters, fatty acid sucrose esters; polyether modified, alkyl aralkyl polyether modified, epoxy poly Silicon-based interfaces such as ether modification, alcohol modification, fluorine modification, amino modification, mercapto modification, epoxy modification, and allyl modification Sex agent; a fluorine-based surfactant such as perfluoroalkyl-ethylene oxide adducts; other lipid systems, biosurfactant, include oligo soap, these at least one can be used.

  Preferred examples of the cationic surfactant include primary amine salts, acylaminoethylamine salts, N-alkyl polyalkylene polyamine salts, fatty acid polyethylene polyamides, amides, and salts thereof, alkylamines such as amine salts, Acylamine salts; alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, alkylpyridium salt, acylaminoethylmethyldiethylammonium salt, acylaminopropyldimethylbenzylammonium salt, acylaminopropyl diethylhydroxyethylammonium salt Quaternary ammonium salts such as acylaminoethyl pyridium salts and diacylaminoethyl ammonium salts or ammonium salts having an amide bond; Esters such as ethylmethylhydroxyethylammonium salt and alkyloxymethylpyridium salt, ammonium salts having an ether bond; alkylimidazolines, 1-hydroxyethyl-2-alkylimidazolines, 1-acylaminoethyl-2-alkylimidazolium salts, etc. Imidazolines, imidazolium salts of amines; amine derivatives such as alkylpolyoxyethyleneamine, N-alkylaminopropylamine, N-acylpolyethylenepolyamine, acylpolyethylenepolyamine, fatty acid triethanolamine ester; other fatty, biosurfactant, oligosoap And at least one of these can be used.

  Examples of anionic surfactants include fatty acid salts, rosin groups, naphthene groups, ether carboxylates, alkenyl succinates, N-acyl sarcosine salts, N-acyl glutamates, primary alkyl sulfates, secondary alkyl sulfates. Carboxylic acid salts such as anealkyl sulfate polyoxyethylene salt, alkylphenyl polyoxyethylene sulfate, monoacylglycerol sulfate, acylaminosulfate ester, sulfate oil, sulfated fatty acid alkyl ester; α-olefin sulfonate, Secondary alkane sulfonate, α-sulfo fatty acid, acyl isethionate, N-acyl-N-methyl taurate, dialkyl sulfosuccinate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl diphenyl ether disulfonate, petroleum sulfone Acid salt, rig Salts of sulfonic acids such as ninsulfonic acid salts; Salts of phosphoric acid esters such as alkyl phosphates and alkyl polyoxyethylene salts; Silicon-based anionic surfactants modified with sulfonic acid and carboxyl; Perfluoroalkylcarboxylic acid Fluorine surfactants such as salts, perfluoroalkyl sulfonates, perfluoroalkyl phosphates, perfluoroalkyltrimethylammonium salts; other lipids, biosurfactants, oligo soaps, and at least one of these can be used.

  Preferable examples of the polymeric surfactant include poly (meth) acrylic acid, butyl (meth) acrylate-acrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, and other polyalkyl ( (Meth) acrylic acid homopolymer or copolymer; vinyl acetate-maleic anhydride copolymer, styrene-maleic anhydride copolymer, α-olefin-maleic anhydride copolymer, diisobutylene-maleic acid copolymer Maleic acid copolymers such as coalescence; Fumaric acid copolymers such as methyl (meth) acrylate-fumaric acid copolymer, vinyl acetate-fumaric acid copolymer; Naphthalenesulfonic acid formalin condensate, Butylnaphthalenesulfonic acid formalin condensation , Aromatic sulfonic acid formalin condensate such as cresol sulfonic acid formalin condensate; poly N- Polyalkylpyridinium salts such as tilvinylpyridinium chloride (including derivatives from copolymers of vinylpyridine and vinyl monomers copolymerized therewith); polyacrylamide, polyvinylpyrrolidone, polyacryloylpyrrolidone, polyvinyl alcohol, polyethylene glycol; poly Examples include block polymers of oxyethylene and polyoxypropylene; cellulose derivatives such as methylcellulose and carboxymethylcellulose; polyoxyalkylene / polysiloxane copolymers; polysaccharide derivatives such as arabic gum and arabinogalactan, and at least one of these can be used. In the specific example of the polymer surfactant, the polymer surfactant having a carboxyl group or a sulfone group may be an alkali salt such as sodium, potassium, or ammonium.

  Further, the composition of the heat-meltable particles may be continuously changed 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 a heat-meltable particle, 1-90 mass% of the whole layer is preferable, and 5-80 mass% is still more preferable.

(Heat-bonding particles)
Examples of the heat-fusible particles include thermoplastic hydrophobic polymer particles, and there is no specific upper limit for the softening temperature of the thermoplastic hydrophobic polymer particles. It is preferable that the temperature is lower than the decomposition temperature. Moreover, it is preferable that the weight average molecular weight (Mw) of a high molecular weight polymer is the range of 10,000-1,000,000.

  Specific examples of the polymer constituting the thermoplastic hydrophobic polymer particles include, for example, diene (co) polymers such as polypropylene, polybutadiene, polyisoprene, and ethylene-butadiene copolymer, and styrene-butadiene. Synthetic rubbers such as copolymer, 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, acetic acid Vinyl-ethylene copolymer weight Vinyl ester (co) polymer such as a body, 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 thermoplastic hydrophobic polymer particles may be made of a polymer polymer polymerized by any known method such as emulsion polymerization, suspension polymerization, solution polymerization, and gas phase polymerization. As a method for making a polymer polymer polymerized by a solution polymerization method or a gas phase polymerization method into a fine particle, a solution is sprayed in an inert gas in an organic solvent of the polymer polymer and dried to make a fine particle, Examples include a method in which a high molecular polymer is dissolved in an organic solvent immiscible with water, this solution is dispersed in water or an aqueous medium, and the organic solvent is distilled off to form fine particles.

  Further, in any method, the heat-meltable particles and the heat-fusible particles may be used as a dispersant or a stabilizer, for example, when polymerized or granulated, for example, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, polyethylene A surfactant such as glycol or a water-soluble resin such as polyvinyl alcohol may be used. Further, triethylamine, triethanolamine or the like may be contained.

  The heat-fusible particles are preferably dispersible in water, and the average particle diameter is preferably 0.01 to 10 μm, more preferably 0.1 to 10 μm from the viewpoint of on-press developability and resolution. 3 μm.

  Further, the composition of the heat fusible particles may be continuously changed 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-fusible particle | grains in a structural layer, 1-90 mass% of the whole layer is preferable, and 5-80 mass% is still more preferable.

(Water-soluble binder)
Examples of the water-soluble binder that can be used in the image forming functional layer include polysaccharides, polyethylene oxide, polypropylene oxide, polyvinyl alcohol, polyethylene glycol (PEG), polyvinyl ether, styrene-butadiene copolymer, and methyl methacrylate-butadiene copolymer. Conjugated diene polymer latex, acrylic polymer latex, vinyl polymer latex, polyacrylamide, polyacrylic acid or salts thereof, and resins such as polyvinylpyrrolidone. Among them, it is preferable to use polyacrylic acid or a salt or polysaccharide thereof that does not deteriorate the printing performance.

  The image forming functional layer according to the present invention preferably contains lower alcohols such as methanol, ethanol, isopropropanol, and butanol in order to improve the coating quality. Moreover, the photothermal conversion raw material mentioned later can be contained.

The dry coating mass of the image forming functional layer is preferably 0.1 to 1.5 g / m ² , more preferably 0.15 to 1.0 g / m ² .

(Hydrophilic layer)
The printing plate material of the present invention preferably has a constitution having at least one hydrophilic layer between the polyester support and the image forming functional layer.

  The hydrophilic layer will be described.

  The hydrophilic layer is a layer that can be a non-image part having low affinity for ink and repelling ink when using the printing plate material of the present invention as a printing plate and having high affinity for water and retaining water. .

  In the present invention, it is preferable that the hydrophilic layer provided on the support has a porous structure.

  In order to form the hydrophilic layer having the porous structure, materials for forming the hydrophilic matrix described below are preferably used.

  As a material for forming the hydrophilic matrix, a metal oxide is preferable.

(Metal oxide)
The metal oxide preferably contains metal oxide particles, and examples thereof include colloidal silica, alumina sol, titania sol, and other metal oxide sols. The form of the metal oxide particles may be spherical, needle-like, feather-like or any other form. The average particle diameter is preferably in the range of 3 to 100 nm, and several kinds of metal oxide particles having different average particle diameters. Can also be used together. 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.

(Colloidal silica)
Among these, colloidal silica can be particularly preferably used. 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-like colloidal silica, which will be described later, and a fine particle colloidal silica having an average particle size of 20 nm or less. Further, the colloidal silica preferably exhibits alkalinity when used as a colloidal solution.

  Necklace-shaped colloidal silica is a general term for an aqueous dispersion of spherical silica whose primary particle diameter is of the order of nm, and spherical colloidal silica having a primary particle diameter of 10 to 50 nm bonded to a length of 50 to 400 nm. It means colloidal silica in the form of “pearl necklace”. 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 connected and connected has a shape 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., and the product name is “Snowtex-PS-S” (the average particle diameter in the connected state is 110 ")," Snowtex-PS-M (average particle size in the connected state is about 120 nm) "and" Snowtex-PS-L (average particle size in the connected state is about 170 nm) " Acidic products corresponding to the above 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, alkaline “Snowtex PS-S”, “Snowtex PS-M” and “Snowtex PS-L” improve the strength of the hydrophilic layer, and even when the number of printed sheets is large, The occurrence of dirt is suppressed, which is particularly preferable.

  Further, it is known that the colloidal silica has a stronger binding force as the particle diameter is smaller. In the present invention, it is preferable to use colloidal silica having an average particle diameter of 20 nm or less, more preferably 3 to 15 nm. is there.

  As described above, among the colloidal silica, an alkaline one is particularly preferable because it has an effect of suppressing the occurrence of soiling. Examples of the alkaline colloidal silica having an average particle diameter in this range include, for example, “Snowtex-20 (particle diameter 10-20 nm)”, “Snowtex-30 (particle diameter 10-20 nm)” manufactured by Nissan Chemical Co., Ltd. “Snowtex-40 (particle diameter 10-20 nm)”, “Snowtex-N (particle diameter 10-20 nm)”, “Snowtex-S (particle diameter 8-11 nm)”, “Snowtex-XS (particle diameter) 4-6 nm) ".

  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 to be formed, when used in combination with the aforementioned necklace-like colloidal silica.

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

  In the present invention, porous metal oxide particles having a particle size of less than 1 μm can be contained as a porous material having a hydrophilic layer matrix structure.

(Porous metal oxide particles)
As the porous metal oxide particles, the following porous silica particles, porous aluminosilicate particles, or zeolite particles can be preferably used.

(Porous silica particles, porous aluminosilicate particles)
The porous silica particles are generally produced by a wet method or a dry method. In the wet method, the gel obtained by neutralizing the aqueous silicate solution can be obtained by drying and pulverizing, or by pulverizing the precipitate deposited by neutralization. In the dry method, silicon tetrachloride is burned together with hydrogen and oxygen to obtain silica. These particles can be controlled in their porosity and particle size by adjusting the production conditions. As the porous silica particles, those obtained from a wet gel are particularly preferable.

  The porous aluminosilicate particles are produced, for example, by the method described in JP-A-10-71764. That is, amorphous composite particles 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. Moreover, what was manufactured as composite particle | grains of 3 or more components by adding the alkoxide of another metal at the time of manufacture can be used for this 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. 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. Conversely, if the pore volume is less than 0.5 ml / g, the printing performance may be slightly insufficient.

(Measurement method of pore volume)
Here, the pore volume is measured by using Autosorb-1 (manufactured by Cantachrome) and assuming that the voids of the powder are filled with nitrogen by nitrogen adsorption measurement using a constant volume method. The relative pressure is calculated from the nitrogen adsorption amount at 0.998.

(Zeolite particles)
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.

  Moreover, the hydrophilic layer matrix structure which comprises a hydrophilic layer can contain a layered mineral particle.

  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 polysilicic acid. Examples thereof include salts (kanemite, macatite, ialite, magadiite, kenyaite, etc.). In particular, 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. Further, 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 for the size of the layered mineral particles, the average particle size (maximum length of the particles) is less than 1 μm, and the average aspect ratio is contained in the layer (including the case of undergoing the swelling process and dispersion peeling process). 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. Further, 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 the 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 in powder form 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 to prepare a gel swollen in water and then add it to the coating solution.

For the hydrophilic layer matrix constituting the hydrophilic layer, an aqueous silicate solution can also be used as another additive material. 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 / Agne Jofusha) or in this book Known methods described in the cited documents can be used.

  The hydrophilic layer may contain a water-soluble resin.

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

  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. In order to obtain a structure having better printability, it is preferable to form 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 determined by 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 wetness. It is possible to appropriately control the film thickness, drying conditions, and the like.

  The water-soluble resin added to the hydrophilic matrix structure part 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. Further, it may further contain a cationic resin. Examples of the cationic resin include polyalkylene polyamines such as polyethylene amine and polypropylene polyamine or derivatives thereof, tertiary amino groups and quaternary ammonium groups. Examples thereof include acrylic resin and diacrylamine. The cationic resin may be added in the form of fine particles, and examples thereof include a cationic microgel described in JP-A-6-161101.

  The coating solution used to coat the hydrophilic layer can contain a water-soluble surfactant for the purpose of improving the coating property, and use a surfactant such as Si-based or F-based. However, it is 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).

  The hydrophilic layer 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.

(Photothermal conversion material)
The image forming functional layer according to the present invention or the hydrophilic layer preferably contains a photothermal conversion material. Examples of the photothermal conversion material include infrared absorbing dyes or pigments.

(Infrared absorbing dye)
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-280750, JP-A-1-293342, JP-A-2-2074, JP-A-3-26593, 3-30991, 3-34891, 3-36093, 3-36094, 3-36095, 3-42281, 3-97589, 3-103476, 7 -43851, 7-102179, JP-A-2001-117201, and the like. These can be used alone or in combination of two or more.

  Examples of the pigment include carbon, graphite, metal, metal oxide and the like.

  As carbon, furnace black or acetylene black is particularly preferable. The particle size (d50) is preferably 100 nm or less, and more preferably 50 nm or less.

  As the graphite, fine particles having a particle size of 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less can be used.

  As the metal, any metal can be used as long as the particle diameter is 0.5 μm or less, preferably 100 nm or less, more preferably 50 nm or less. The shape may be any shape such as a spherical shape, a piece shape, or a needle shape. Colloidal metal fine particles (Ag, Au, etc.) are particularly preferable.

As the metal oxide, a material that is black in the visible light region or a material that is conductive or that is a semiconductor can be used. Examples of the material exhibiting black color in the visible light region include black iron oxide (Fe ₃ O ₄ ) and black mixed metal oxides containing two or more of the aforementioned metals. The metal oxide is a black complex metal oxide composed of two or more kinds of metal oxides. 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 can be produced by the methods disclosed in JP-A-8-27393, 9-25126, 9-237570, 9-241529, and 10-231441. The composite metal oxide that can be 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-8-27393 in order to reduce the elution of hexavalent chromium. These composite metal oxides are colored with respect to the amount added, that is, 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. Although the kind of dispersing agent is not specifically limited, it is preferable to use Si type surfactant containing Si element.

Examples of materials that have conductivity or are semiconductors include reduced Sb-doped SnO ₂ (ATO), Sn-added In ₂ O ₃ (ITO), TiO ₂ , and TiO ₂ . Examples thereof include TiO (titanium oxynitride, generally titanium black). Further, it is also possible to use 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.

  A particularly preferable embodiment of the photothermal conversion material is that the infrared absorbing dye and the metal oxide are black complex metal oxides composed of two or more metal oxides.

  As addition amount of these photothermal conversion raw materials, it is 0.1-50 mass% with respect to the layer containing this, 1-30 mass% is preferable, and 3-25 mass% is more preferable.

(Hydrophilic overcoat layer)
In the present invention, a hydrophilic overcoat layer may be provided as an upper layer of the image forming functional layer in order to prevent damage during handling.

  The hydrophilic overcoat layer may be a layer immediately above the image forming functional layer, or an intermediate layer may be provided between the image forming functional layer and the hydrophilic overcoat layer. The hydrophilic overcoat layer is preferably removable on a printing press.

(exposure)
The printing plate material of the present invention is image-exposed with a laser beam in accordance with image data from the surface having the image forming functional layer, and then developed on a printing machine to obtain a printing plate.

  That is, the printing plate of the present invention is obtained by developing the printing plate material on a printing machine after image exposure with a laser beam.

  In the present invention, more specifically, 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 is preferable.

  Although a gas laser may be used as the laser, it is particularly preferable to perform scanning exposure using a semiconductor laser that emits light in the near infrared region.

  As an apparatus suitable for scanning exposure that can be used in 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 a semiconductor laser. There may be.

  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 flat plate holding mechanism; ) A printing plate material held along a cylindrical surface inside a fixed cylindrical holding mechanism, and using one or more laser beams from the inside of the cylinder in the circumferential direction of the cylinder (main scanning direction) A method in which the entire surface of the printing plate material is exposed by moving in a direction perpendicular to the circumferential direction (sub-scanning direction) while scanning, and (3) printing held on the surface of a cylindrical drum that rotates about an axis as a rotating body The plate material is printed by moving in the direction perpendicular to the circumferential direction (sub-scanning direction) while scanning in the circumferential direction (main scanning direction) by rotating the drum using one or more laser beams from the outside of the cylinder. A method that exposes the entire plate material That.

  The printing plate material on which an image is formed in this manner can be applied to a printing process without performing a wet development process.

  The printing plate material after image exposure is directly attached to the plate cylinder of the printing press, or after the printing plate material is attached to the printing plate cylinder, the water supply roller and / or the ink supply roller is printed while rotating the plate cylinder. It is possible to remove the non-image portion of the image forming functional layer by contacting with the plate material.

  The removal of the non-image part (unexposed part) of the image forming functional layer on the printing press can be performed by contacting a watering roller or an ink roller while rotating the plate cylinder, as in the following examples: Alternatively, it can be performed by various other sequences. In that case, the water amount may be adjusted by increasing or decreasing the amount of dampening water required for printing, and the water amount adjustment may be divided into multiple stages or steplessly. You may change it to.

  (1) As a sequence for starting printing, a watering roller is brought into contact with the plate cylinder to make one to several dozen rotations, then an ink roller is brought into contact with the plate cylinder to make one to several dozen rotations, and then Start printing.

  (2) As a sequence for starting printing, an ink roller is contacted to rotate the plate cylinder from 1 to several tens of revolutions, then a watering roller is contacted to rotate the plate cylinder from one to several tens of rotations, Start printing.

  (3) As a sequence for starting printing, the watering roller and the ink roller are brought into contact with each other substantially simultaneously to rotate the plate cylinder 1 to several tens of times, and then printing is started.

(printing)
As a printing machine used for printing of the present invention, a generally known lithographic offset printing machine using fountain solution and lithographic printing ink can be used.

  In the present invention, the lithographic printing plate material is imagewise exposed as described above, and then developed with dampening water or dampening water and printing ink on a lithographic printing machine to form a printing plate and then printed.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In the examples, “parts” represents “parts by mass” unless otherwise specified.

Example 1
<< Preparation of polyester support >>
(Preparation of support 1)
Using terephthalic acid and ethylene glycol, a polyethylene terephthalate having IV (inherent viscosity) = 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C.) was obtained according to a conventional method.

  This is pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, rapidly cooled on a cooling drum at 50 ° C., and not yet thick enough to have an average film thickness of 175 μm after heat setting. A stretched film was prepared.

  With respect to the drawing temperature, the first drawing was stretched 1.3 times at 102 ° C. and the second drawing was longitudinally stretched 2.6 times at 110 ° C. Next, it was stretched 4.5 times at 120 ° C. with a tenter. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature.

  Thereafter, the chuck portion of the tenter was slit, knurled at both ends, cooled to 40 ° C., and wound at 47.1 N / m. Thus, a biaxially stretched polyethylene terephthalate film (support 1) having a thickness of 190 μm was obtained.

  The glass transition temperature (Tg) of this biaxially stretched polyethylene terephthalate film was 79 ° C. The obtained polyethylene terephthalate film had a width (film formation width) of 2.5 m.

<< Undercoat coating liquid a >>
Styrene / glycidyl methacrylate / butyl acrylate = 60/39/1 ternary copolymer latex (Tg = 75 ° C.) (solid content basis) 6.3 parts Styrene / glycidyl methacrylate / butyl acrylate = 20/40/40 3 Base copolymer latex 1.6 parts Anionic surfactant S-1 0.1 part Water 92.0 parts << Undercoat coating solution b >>
Gelatin 1 part Anionic surfactant S-1 0.05 part Hardener H-1 0.02 part Matting agent (silica, average particle size 3.5 μm) 0.02 part Antifungal agent F-1 0.01 Water 98.9 parts

<< Undercoating liquid c-1 >>
Styrene / glycidyl methacrylate / butyl acrylate = 20/40/40 terpolymer copolymer latex (solid content basis) 0.4 part Styrene / glycidyl methacrylate / butyl acrylate / acetoacetoxyethyl methacrylate = 39/40/20/1 Quaternary copolymer latex 7.6 parts Anionic surfactant S-1 0.1 part Water 91.9 parts << Undercoat coating liquid d-1 >>
Conductive composition of component d-11 / component d-12 / component d-13 = 66/31/1
6.4 parts Hardener H-2 0.7 parts Anionic surfactant S-1 0.07 parts Matting agent (silica, average particle size 3.5 μm) 0.03 parts Water 93.4 parts Component d- 11: Anionic polymer compound comprising a copolymer of sodium styrenesulfonate / maleic acid = 50/50 Component d-12; Three-component copolymer latex comprising styrene / glycidyl methacrylate / butyl acrylate = 40/40/20 Polymeric activator comprising component d-13; styrene / sodium isoprenesulfonate = 80/20

<< Plasma treatment conditions >>
Using a batch type atmospheric pressure plasma processing apparatus (EC-I-H-340, manufactured by EC Chemical Co., Ltd.), the high frequency output is 4.5 kW, the frequency is 5 kHz, the processing time is 5 seconds, and the gas conditions are argon, Plasma treatment was performed at a volume ratio of nitrogen and hydrogen of 90% and 5%, respectively.

《Heat treatment conditions》
The support after slitting to a width of 1.25 m was subjected to low tension heat treatment at 180 ° C. for 1 minute at a tension of 2 hPa.

Preparation of coating liquid for conductive layer Using the conductive substance shown in Table 5, the coating liquid was adjusted so that the content of the conductive substance shown in Table 5, the binder resin, and the film thickness, and applied with a wire bar, It dried and produced the support body with an electroconductive layer.

  The conductive material and binder resin used are shown below.

A-1: Tin oxide sol (SnO ₂ sol synthesized by the method described in Example 1 of Japanese Examined Patent Publication No. 35-6616 was heated and concentrated so that the solid concentration was 10% by mass, and then pH = 10 with aqueous ammonia. Adjusted to
A-2: Crystalline tin oxide (SnO ₂ / SbO (9/1 mass ratio), average particle size 0.038 μm, 17 mass% dispersion)
A-3: (Comparative Example) Barium oxide (BaO average particle size 0.042 μm, 20% by mass dispersion)
Binder resin B-1: Acrylic resin St (styrene): BA (butyl acrylate): GMA (glycidyl methacrylate) = 20: 40: 40
B-2: Polyester resin (35.4 parts by mass of dimethyl terephthalate, 33.63 parts by mass of dimethyl isophthalate, 17.92 parts by mass of dimethyl sodium 5-sulfoisophthalate, 62 parts by mass of ethylene glycol, calcium acetate monohydrate 0.065 parts by mass and 0.022 parts by mass of manganese acetate tetrahydrate were subjected to a transesterification reaction while distilling off methanol at 170 to 220 ° C. in a nitrogen stream, and then 0.04 parts by mass of trimethyl phosphate. Then, 0.04 parts by weight of antimony trioxide and 6.8 parts by weight of 1,4-cyclohexanedicarboxylic acid are added as a polycondensation catalyst, and a theoretical amount of water is distilled off at a reaction temperature of 220 to 235 ° C. for esterification. Then, the reaction system is 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, Obtained hydrophilic polyester resin B-2)
B-3: Acrylic-modified polyester resin (water dispersion of water-soluble copolyester component / acrylic component (80/20)) The water-soluble copolyester component is terephthalic acid / isophthalic acid / cyclohexanedicarboxylic acid / 5-sulfo-isophthalic acid. Mixed component of dimethyl sodium salt (40/38/14/8) and ethylene glycol The acrylic component is a copolymer latex of methyl methacrylate / ethyl acrylate / glycidyl methacrylate (53/37/10) B-4: Cellulose ester Cellulose acetate Propinate (Eastman
(Chemical, CAB482-20)
B-5: (Comparative Example) Polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Co., Ltd., Gohsenol GL05)
B-6: (Comparative example) Polyvinyl acetate (Denka ASR M-4, manufactured by Denki Kagaku Kogyo Co., Ltd.)
(Preparation and application of coating solution for backcoat layer)
The materials listed in Table 1 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare a backcoat layer coating solution.

The coating solution was applied onto the antistatic layer using a wire bar # 6 and passed through a drying zone set to 100 ° C. having a length of 15 m at a conveyance speed of 15 m / min. The amount of the back coat layer applied was 2.0 g / m ² .

(Preparation and coating of hydrophilic coating solution)
The materials listed in Table 2 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare a lower layer hydrophilic coating solution.

  The materials listed in Table 3 were sufficiently stirred and mixed using a homogenizer, and then filtered to prepare an upper hydrophilic coating solution.

The lower hydrophilic layer coating solution is applied to the back surface of the support coated with the backcoat layer using a wire bar # 5, and the drying zone set at 100 ° C. with a length of 15 m is transported at a speed of 15 m / min. It was passed at a speed of Subsequently, the upper hydrophilic layer coating solution was applied using a 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 and upper hydrophilic layers 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 and application of coating solution for image forming functional layer)
The coating solution for the image forming functional layer having the composition shown in Table 4 below was applied to the upper hydrophilic layer prepared above using the wire bar # 5, and the temperature was adjusted to 70 ° C. with a length of 30 m. The set drying zone was passed at a conveyance speed of 15 m / min to form an image forming layer, and printing plate materials 1 to 11 were obtained. The amount of the image forming layer applied was 0.5 g / m ² . The sample after application was aged at 50 ° C. for 2 days.

  Each of the above printing plate materials was cut into a width of 730 mm and wound around a paper core having an outer diameter of 76 mm by 30 m to obtain a rolled planographic printing plate material.

(Evaluation methods)
[Adhesiveness]
Using a razor, the surface of the surface on which the conductive layer of the support was coated was scratched by 6 vertical and horizontal scratches at 4 mm intervals to form 25 squares. However, the scratches were made at a depth that reached the surface of the support. A cello tape (registered trademark) having a width of 25 mm was stuck on this and sufficiently bonded. After 1 minute from the pressure bonding, the cellotape (registered trademark) was peeled off from the sample by abruptly pulling at a peeling angle of 180 degrees. At this time, the number of grids peeled off from the sample by the back coat layer was counted and classified as follows, and used as an index of adhesion between the support and the layer provided on the back surface.
A: Peeling 0
B: Peeling less than 5 squares C: Peeling 5 squares or more [Transportability in plotter]
Using a plotter (SS-830, manufactured by Konica Minolta Co., Ltd.), a sample cut to a width of 730 mm and wound on a paper core having an outer diameter of 76 mm was loaded and discharged until the sample disappeared at a length of 600 mm. The following rank was evaluated and used as an index of transportability.
A: Emission error 0
B: Discharge error is less than 3 C: Discharge error is 3 or more [Attach to plate cylinder]
The operation of printing 100 sheets under the following conditions and removing the printing plate was repeated 10 times, and the number of times of sticking was evaluated according to the following rank, and used as an index for mounting on a printing press.

Printing machine: DAIYA 1F-1 manufactured by Mitsubishi Heavy Industries, Ltd.
Printing paper: Coated paper Dampening solution: Astro Mark 3 (manufactured by Nikken Chemical Laboratories), 2% by mass, ink: Toyo King Hi-Echo M Beni (manufactured by Toyo Ink Co., Ltd.)
A: 0 on the plate cylinder
B: Adhering to plate cylinder less than 3 times C: Adhering to plate cylinder 3 times or more The results are shown in Table 5.

  From Table 5, it can be seen that the printing plate material of the present invention is provided on the back surface and has excellent layer adhesion, excellent transportability in the plate making apparatus, and excellent mounting property to the plate cylinder of a printing press.

Example 2
In the printing plate material 4 of Example 1, the printing plate material 12 was backed up in the printing plate material 5 of Example 1 in the same manner as in Example 1 except that the acrylic emulsion of the back coat layer was changed to the resin B-2. Except that the acrylic emulsion of the coating layer was changed to the resin B-3, the printing plate material 13 was changed in the same manner as in Example 1, and the acrylic emulsion of the backcoat layer in the printing plate material 6 of Example 1 was changed to B-4. A printing plate material 14 was prepared and evaluated in the same manner as in Example 1 except that the resin was replaced with the same resin. The printing plate materials 12, 13, and 14 exhibited the same performance as the printing plate materials 4, 5, and 6, respectively.

Claims (6)

In a printing plate material having an image forming functional layer on one side of a polyester support and a conductive layer containing a conductive substance on the other side, the conductive substance is tin oxide, A printing plate material comprising: a backcoat layer; and the conductive layer and the backcoat layer each contain a polyester resin, an acrylic resin, or a cellulose ester resin. The printing plate material according to claim 1, wherein the image forming functional layer is a layer that can be developed on a printing press. The printing plate material according to claim 1 or 2, wherein the image-forming functional layer contains heat-fusible particles or heat-fusible particles. The printing plate material according to any one of claims 1 to 3, further comprising a layer containing a photothermal conversion material on a side having the image forming functional layer. A printing plate obtained by developing the printing plate material according to any one of claims 1 to 4 on a printing press after image exposure with a laser beam. A printing method using the printing plate according to claim 5.