JP2019132915A - Manufacturing method of photosensitive lithographic printing plate - Google Patents

Abstract

To provide a manufacturing method of a photosensitive lithographic printing plate capable of suitably preventing ink stains, especially fingerprint stains even when stored under a high temperature high humidity condition.SOLUTION: After a photosensitive lithographic printing plate having at least a hydrophilic layer on a supporter, and a photosensitive layer containing a compound having a polymerizable double bond group on the hydrophilic layer is exposed to an image shape, and the photosensitive lithographic printing plate is treated with a treatment liquid containing a water-soluble polymer compound by grafting polyvinyl pyrrolidone to polyvinyl alcohol before being subjected to printing.SELECTED DRAWING: None

Description

  The present invention relates to a plate making method of a photosensitive lithographic printing plate having at least a hydrophilic layer on a support and a photosensitive layer containing a compound having a polymerizable double bond group on the hydrophilic layer.

  There are various application fields for photosensitive compositions using photopolymerization, but in particular, in the field related to lithographic printing plates, in recent years, it has been directly applied to digital data produced on a computer without being output on a film. Computer-to-plate (CTP) technology for outputting on a printing plate has been developed, and various plate setters equipped with various lasers as output machines and photosensitive lithographic printing plates suitable for these have been actively developed.

  Important issues or requests that have been raised with the spread of the CTP method include various points related to development processing. In a normal CTP method, a photosensitive lithographic printing plate is laser-exposed, and a non-image portion is eluted with an alkaline developer, and is subjected to printing through a water washing and gumming process. However, alkaline developers are harmful to the human body, and sufficient care and management are required for their handling and storage.

  Examples of negative photosensitive lithographic printing plates that avoid the use of a strong alkaline agent-containing developer as described above and can be developed with water or the like include, for example, JP-A No. 2003-215801, JP-A No. 2008-265297, This is described in detail in JP 2009-226596 A, JP 2010-237559 A, JP 2010-231133 A, JP 2010-224188 A, and the like.

  These photosensitive lithographic printing plates are provided on a support with a hydrophilic layer serving as a non-image portion that selectively receives water during printing, and a photosensitive layer serving as an image portion that selectively receives ink during printing. Have. The photosensitive layer of the photopolymerized portion exposed imagewise in the exposure step is exposed to the image portion, and the other photosensitive layer portion is washed off during development to expose the hydrophilic layer.

  In order for the exposed hydrophilic layer to function as a non-image portion during printing, it is necessary to prevent ink smear. However, when the developability is unsuitable, the photosensitive layer remains as a residual film on the non-image area and often causes ink stains.

  In each of the above-mentioned publications, as a method for improving developability, various anionic, cationic and nonionic surfactants and isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol, etc. A method of developing with a developer containing a water-soluble organic solvent or the like is described, and International Publication No. 2013/058197 pamphlet, JP-A-2006-133642, etc. describe that the developer is a polyoxyethylene alkyl ether, Nonionic properties such as polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters, alkylbenzene sulfonates, alkylnaphthalenes Acid salts, alkyl sulfates, alkyl sulfonates, anionic such as sulfosuccinic acid ester salts, alkyl betaines, it has been described that may contain amphoteric and amino acids.

  The hydrophilic layer of the photosensitive lithographic printing plate described above includes a hydrophilic layer formed by anodizing an aluminum plate and an inorganic filler of 60% by mass or more based on the total solid content of the hydrophilic layer. It is already known that the hydrophilic layer is preferably used. For example, the latter hydrophilic layer is disclosed in the above-mentioned International Publication No. 2013/058197, JP2013-216080, and JP2013-2013. No. 130697 and the like.

  On the other hand, these photosensitive lithographic printing plates are not necessarily printed immediately after development, and often start printing after being stored for a certain period of time. In this case, if the non-image part is directly touched with a finger or the like, a sebum component adheres to the hydrophilic layer, causing a printing stain, that is, a so-called fingerprint stain, and normal printing is performed. It becomes difficult to continue.

  As a method for preventing fingerprint stains, it is widely known that a water-soluble polymer compound is allowed to act. For example, JP-A-2004-243600 (Patent Document 1) is characterized by containing cyclodextrin or a derivative thereof. JP-A-2003-196628 (Patent Document 2) discloses a plate-making method characterized in that it is treated with a plate-side protective liquid containing soybean polysaccharide. Patent Document 3) discloses a plate making method characterized by processing with a processing solution containing gum arabic after development. JP-A-10-319607 (Patent Document 4) discloses an acid or a buffer and a nonionic activator, Each of the treatment agents characterized by containing a water-soluble polymer compound is described.

  However, all of these methods have insufficient effects, and there has been a demand for a plate making method that does not cause fingerprint smearing even when stored under high temperature and high humidity conditions.

JP 2004-243600 A JP 2003-196628 A JP 2000-206697 A Japanese Patent Laid-Open No. 10-319607

  An object of the present invention is to provide a method for making a photosensitive lithographic printing plate which can suitably prevent ink stains, particularly fingerprint stains, even when stored under high temperature and high humidity conditions.

  An object of the present invention described above is to imagewise expose a photosensitive lithographic printing plate having at least a hydrophilic layer on a support and a photosensitive layer containing a compound having a polymerizable double bond group on the hydrophilicity. Then, before the photosensitive lithographic printing plate is used for printing, the photosensitive lithographic printing plate is made with a treatment liquid containing a water-soluble polymer compound obtained by grafting polyvinyl pyrrolidone to polyvinyl alcohol. It can be solved by the method.

  According to the present invention, even when a lithographic printing plate is stored under high temperature and high humidity conditions, it is possible to obtain a printing plate having good quality without causing fingerprint smearing in the non-image area.

  The water-soluble polymer compound contained in the treatment liquid used in the present invention (hereinafter also referred to as the treatment liquid of the present invention) is a compound obtained by grafting polyvinyl pyrrolidone to polyvinyl alcohol, for example, from Daiichi Kogyo Seiyaku Co., Ltd. Commercially available Pitz Call (registered trademark) V-7154 or the like can be used. The content of the water-soluble polymer compound in the treatment liquid of the present invention is not particularly limited, but is preferably 0.01 g / L or more, more preferably 0.1 g / L or more, and further preferably 1.0 g / L. L or more. The upper limit is desirably 50 g / L or less.

  In addition to the above water-soluble polymer compound, the treatment liquid used in the present invention includes polyoxyethylene alkyl ether type surface activity such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and polyoxyethylene stearyl ether. Agents, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene alkyl ester type surfactants such as polyoxyethylene monooleate, and nonionic surfactants such as polyoxyethylene-polyoxypropylene block polymers It can also contain 1 or more types of these together. The content of these nonionic surfactants is preferably 1 to 100 g / L, more preferably 5 to 50 g / L, based on the liquid used. When the content is increased, the ink deposition property of the image area may be lowered.

  Furthermore, the treatment liquid used in the present invention preferably contains a polyol compound or a glycol derivative for the purpose of more effectively preventing ink stains by enhancing the moisturizing effect of the non-image area. Specific examples of these compounds include, for example, ethylene glycol, trimethylene glycol, propylene glycol, 1,3-butylene glycol, hexylene glycol, diethylene glycol, triethylene glycol, glycerin, polyethylene glycol (molecular weight 200 to 600), dipropylene glycol. And tripropylene glycol. The content of these polyol compounds or glycol derivatives is preferably in the range of 10 to 200 g / L.

  The treatment liquid used in the present invention is preferably in the range of pH 4.5 to 7.5, more preferably in the range of 5.0 to 7.0. As a pH adjuster, buffering agents, such as phosphoric acid, polyphosphoric acid, phytic acid, a citric acid, a succinic acid, adipic acid, or those salts can be contained, for example.

  Further, in the treatment liquid used in the present invention, if necessary, chelating agents such as ethylenediaminetetraacetic acid and triethylenetetraminehexaacetic acid, rust preventives such as diethanolamine and benzotriazole, benzotriazole derivatives, 4-isothiazoline-3- It can contain antiseptics such as ON compounds, and antifoaming agents such as silicone and alkylene glycol compounds. Moreover, other water-soluble polymer compounds, such as polyacrylic acid and its salt, gum arabic, and carboxymethylcellulose, can also be contained.

  As the photosensitive lithographic printing plate used in the present invention, for example, a photosensitive lithographic printing plate having a hydrophilic layer formed by anodizing the surface of an aluminum support, or an inorganic filler on a plastic film support. And a photosensitive lithographic printing plate having a hydrophilic layer. Conventionally, when making a photosensitive lithographic printing plate having a hydrophilic layer containing an inorganic filler, if the wash-off property at the time of development is inappropriate, the photosensitive layer remains as a residual film in the gap between the inorganic fillers. As a result, it has been pointed out that ink stains are likely to occur when sebum or the like adheres as a result of a decrease in the hydrophilicity of the non-image area. In particular, when the developer used is water or a neutral developer, the desensitization function of the non-image area obtained with a strong alkaline developer cannot be obtained, and this problem has occurred remarkably. .

  The effect of the present invention can be exhibited by the presence of a water-soluble polymer compound obtained by grafting polyvinyl pyrrolidone to polyvinyl alcohol on the non-image area of the photosensitive lithographic printing plate. Therefore, as an embodiment of the present invention, for example, a developer used for making a photosensitive lithographic printing plate that can be made using water or a neutral developer, for the purpose of removing stains on the plate surface after development, is used. It can be applied to the washing solution used or the finishing solution used for the purpose of protecting the plate surface and imparting hydrophilicity in the final step of plate making, but the treatment solution of the present invention is the final treatment used during plate making. A liquid is preferred.

  Hereinafter, a photosensitive layer containing a hydrophilic layer containing an inorganic filler on a plastic film support that can be developed with water or the like suitably used in the present invention, and a compound having a polymerizable double bond group on the hydrophilic layer. The photosensitive lithographic printing plate having at least a layer will be described in detail.

  Typical examples of the plastic film used as the plastic film support include polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, and cellulose nitrate. In particular, polyethylene terephthalate and polyethylene naphthalate are preferably used.

  The surface of the support may be surface-treated in order to improve adhesion with a hydrophilic layer or a backcoat layer provided as necessary. Examples of such surface treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment. As a further surface treatment, an undercoat layer may be provided on the support in order to enhance the adhesion with the hydrophilic layer provided on the plastic film support.

  Examples of the inorganic filler contained in the hydrophilic layer include calcium carbonate, magnesium carbonate, zinc oxide, titanium dioxide, barium sulfate, aluminum hydroxide, zinc hydroxide, colloidal silica, pore silica, and kaolin. Of these, titanium dioxide, barium sulfate, aluminum hydroxide, and colloidal silica are preferable.

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

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

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

  Colloidal silica is obtained by heating and aging a silica sol obtained by metathesis of sodium silicate with an acid or the like or through an ion exchange resin layer. Alternatively, it can also be produced by a liquid phase synthesis method such as hydrolysis of an alkoxide. For example, from Nissan Chemical Industries Ltd. Snowtex (registered trademark) XS, Snowtex S, Snowtex 20, MP-2040, MP-1040, Snowtex ZL, Snowtex O, Snowtex OL, Snowtex UP, Snowtex PS -S, Snowtex PS-M, etc. are commercially available and can be used.

  Further, in the particle size distribution of the inorganic filler contained in the hydrophilic layer, the peak exists in the range of 0.2 μm or more and less than 0.6 μm and in the range of 0.6 μm or more and less than 1.5 μm, and 0.2 μm or more and 0.6 μm. When the distribution frequency of the inorganic filler existing in the range of less than fx is fx and the distribution frequency of the inorganic filler existing in the range of 0.6 μm or more and less than 1.5 μm is fy, the fx / fy ratio is 1.5 or more, The distribution frequency fy is preferably 25% or more. The fx / fy ratio is more preferably 2.0 or more, and the upper limit of the fx / fy ratio is less than 3.5. In the above-mentioned range, for example, when a plurality of peaks are present in the range of 0.2 μm or more and less than 0.6 μm, the distribution frequency fx may be obtained with the higher peak. In the case where the height of the recess between two peaks is 60% or more of the higher peak, it is regarded as one peak.

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

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

  In order to obtain the particle size distribution of the inorganic filler described above, an inorganic filler having an average primary particle size of 0.1 μm or more and less than 0.6 μm and an inorganic filler having an average primary particle size of 0.6 μm or more and less than 2.0 μm are combined. It is preferable to use it, and if it is such a combination, the inorganic filler may be further used in combination with three or four kinds.

  In addition, it is desirable that the content of the silicon-containing compound is small in the entire inorganic filler having the above particle size distribution. The silicon-containing compound is colloidal silica, pore silica, kaolin, or the like, and is preferably used at 5% by mass or less, more preferably 3% by mass or less, particularly 1% by mass with respect to the total inorganic filler. It is desirable to use in the following.

  Further, the hydrophilic layer includes, for example, proteins such as gelatin and gelatin derivatives, or cellulose derivatives, gum arabic, starch and derivatives thereof, cellulose derivatives (eg hydroxypropylmethylcellulose), glycogen, agarose, pectin, dextran, pullulan and other polysaccharides, Synthetic polymer compounds such as polyvinyl alcohol, modified polyvinyl alcohol, polyvinylpyrrolidone, styrene / maleic acid copolymer salt, styrene / acrylic acid copolymer salt, and acrylamide polymer can be contained.

  Other components that can be contained in the hydrophilic layer include, for example, melamine resin, epoxy resin, polyisocyanate compound, aldehyde compound, silane compound, chromium alum, divinylsulfone, etc. for the purpose of improving the film strength and adhesive strength of the hydrophilic layer. For example, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkyls for the purpose of improving the coating properties of coating solutions containing a high concentration of the inorganic filler in the hydrophilic layer. Anionic surfactants such as ether sulfate, palm oil fatty acid amide propyl betaine, lauric acid amide propyl betaine, myristic acid amide propyl betaine, octanoic acid amide propyl betaine and other fatty acid amide alkyl betaine type amphoteric surfactants, lauryl dimethylamino Acetic acid Alkylbetaine-type amphoteric surfactants such as allyldimethylaminoacetic acid, sulfobetaine-type amphoteric surfactants such as dodecylaminomethyldimethylsulfopropylbetaine, octadecylaminomethyldimethylsulfopropylbetaine, sodium lauroylglutamate, potassium lauroylglutamate, lauroylmethyl- Amino acid type amphoteric surfactants such as β-alanine and amine oxide type amphoteric surfactants such as lauryldimethylamine N-oxide and oleyldimethylamine N-oxide can be contained.

  The dry solid content of the hydrophilic layer is preferably in the range of 0.1 to 20 g / L, and more preferably in the range of 0.2 to 10 g / L. The proportion of the inorganic filler contained in the hydrophilic layer is preferably 60% by mass or more based on the total dry solid content from the viewpoint of stain resistance.

  Next, the photosensitive layer containing a compound having a polymerizable double bond group provided on the hydrophilic layer will be described.

  The compound having a polymerizable double bond group can be used by mixing one or more compounds selected from a polymer group and a low molecular compound group.

  The polymer compound having a polymerizable double bond group is a polymer compound formed by an arbitrary repeating unit, and is a polymer compound in which a polymerizable double bond group is bonded to a side chain through an arbitrary linking group. is there. Among them, a polymer compound having a vinyl group as a polymerizable double bond group is preferably used, and a polymer compound in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or via an arbitrary linking group is particularly preferably used. . In addition, it is preferable to introduce a carboxyl group, a sulfo group, a quaternary ammonium group, or the like linked to the main chain via an arbitrary linking group, but among them, a polymer compound having a sulfo group is preferably used because of its high developability. be able to. The sulfo group may form a salt (for example, sodium salt, potassium salt, lithium salt, ammonium salt, etc.). These linking groups are not particularly limited, and include any group, atom, or a combination thereof. The phenyl group and sulfo group substituted with a vinyl group may be independently bonded to the main chain, or the phenyl group substituted with a vinyl group and the sulfo group share part or all of the linking group. You may combine with.

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

  With respect to the polymer compound having a polymerizable double bond group, for example, JP 2012-203131, JP 2012-208152, JP 2012-208331, JP 2012-208332, JP 2013. -20103 and the like, and can be used in the present invention.

  In the present invention, the photosensitive layer preferably contains a low molecular compound having a polymerizable double bond group together with the polymer compound having a polymerizable double bond group. The low molecular compound having a polymerizable double bond group in this case can be preferably used as long as it is a compound that undergoes polymerization by radicals generated by photolysis of a photopolymerization initiator. Furthermore, when a compound having two or more polymerizable double bond groups in the molecule is used, a cross-linked product is formed as a result of polymerization by radicals, so that it is excellent in printing durability and ink transportability. It can be used very preferably to give a printing plate. Examples of compounds having a polymerizable double bond group that can be used for such purposes include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tetraethylene glycol diacrylate. Polyfunctional acrylic monomers such as trisacryloyloxyethyl isocyanurate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or acryloyl group, methacryloyl group Polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, etc. are also used in the same way as various oligomers introduced with That.

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

  Specific examples of the trihaloalkyl-substituted compound that is a photopolymerization initiator include compounds having at least one trihaloalkyl group such as a trichloromethyl group and a tribromomethyl group in the molecule, and preferred examples include the trihaloalkyl group. Examples of the compound in which a group is bonded to a nitrogen-containing heterocyclic group include s-triazine derivatives and oxadiazole derivatives, or a trihaloalkyl in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocyclic ring via a sulfonyl group Examples include sulfonyl compounds.

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

  The photosensitive layer of the photosensitive lithographic printing plate used in the present invention preferably contains a silane coupling agent. An excellent printing durability can be obtained when the photosensitive layer contains a silane coupling agent. In the photosensitive lithographic printing plate having the hydrophilic layer of the present invention, the stain resistance, the antifogging property, and the ink are used. This is particularly preferable because the printing durability is improved without lowering the detachability.

  Examples of silane coupling agents include epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, methyltri Methoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, hexyltrimethoxysilane , Decyltrimethoxysilane, vinyltris (3-methoxyethoxy) silane, vinyltriet Sisilane, vinyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) -aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloro B pills trimethoxysilane, 3-isocyanatopropyltriethoxysilane, etc. it is possible to contain. Among them, epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltri Particularly preferred are trialkoxysilanes such as ethoxysilane. In addition, a silane coupling agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The photosensitive layer of the present invention is preferably a layer formed by applying and drying an aqueous coating solution containing at least an emulsion in water of a compound having a photopolymerization initiator and a polymerizable double bond group. In preparing an emulsion in water containing the above-mentioned components, a photopolymerization initiator and a compound having a polymerizable double bond group are emulsified and dispersed in water in the presence of an anionic surfactant, so that they are exposed to a certain high temperature. However, it is preferable because an underwater emulsion capable of stably maintaining an emulsified dispersion state can be obtained. In addition, it is preferable from the viewpoint of storage stability of the coating liquid that a photopolymerization initiator, a compound having a polymerizable double bond group, and a sensitizing dye are emulsified and dispersed in water in the presence of an anionic surfactant.

  Examples of anionic surfactants used for emulsification and dispersion include higher fatty acid salts such as sodium laurate, sodium stearate and sodium oleate, alkyl sulfates such as sodium dialkylsulfosuccinate, sodium lauryl sulfate and sodium stearyl sulfate, and octyl. Sodium alcohol sulfate, sodium lauryl alcohol sulfate, higher alcohol sulfates such as ammonium lauryl alcohol sulfate, aliphatic alcohol sulfates such as sodium acetyl alcohol sulfate, alkylbenzene sulfonates such as sodium dodecylbenzene sulfonate, Alkyl naphthalene sulfones such as sodium butyl naphthalene sulfonate and sodium isopropyl naphthalene sulfonate Salts, alkyl diphenyl ether disulfonates such as sodium alkyl diphenyl ether disulfonate, alkyl phosphate esters such as sodium lauryl phosphate and sodium stearyl phosphate, polyethylene oxide adducts of sodium lauryl ether sulfate, polyethylene oxide adducts of lauryl ether ammonium sulfate, lauryl ether Polyethylene oxide adducts of alkyl ether sulfates such as polyethylene oxide adduct of triethanolamine sulfate, polyethylene oxide adducts of alkyl phenyl ether sulfates such as polyethylene oxide adduct of sodium nonylphenyl ether sulfate, sodium lauryl ether phosphate Polyether of alkyl ether phosphate such as polyethylene oxide adduct Alkylene oxide adducts, and polyethylene oxide adducts, and the like alkyl phenyl ether phosphate polyethylene oxide adduct of nonyl phenyl ether sodium phosphate. Of these, sodium dialkylsulfosuccinate, alkyl naphthalene sulfonates, and polyethylene oxide adducts of alkyl ether sulfates are particularly preferable because of the most improved dispersion stability.

  In addition, the dispersion stability of the emulsion in water is further improved by adding the above-described polymer compound having a polymerizable double bond group and a sulfo group forming a salt to the system and emulsifying and dispersing. Since the polymer compound is water-soluble, it may be added at the time of emulsification dispersion for preparing an emulsion in water, or may be added after emulsification dispersion. Since the dispersed particle diameter is remarkably reduced and dispersed in the form of extremely fine droplets and fine particles, problems such as sedimentation or levitation over time are suppressed, which is more preferable. Furthermore, a part of the polymer compound is preferably used at the time of dispersion to prepare a dispersion, and after the stable dispersion is prepared, the polymer compound is preferably added.

  The dispersion method for emulsifying and dispersing is not particularly limited, and any disperser such as a rotary disperser, a media mill such as a bead mill or a ball mill, an ultrasonic disperser or a kneader can be used. A commercially available apparatus such as a homogenizer or a sand grinder can be preferably used.

  In preparing an emulsion in water, a compound having a photopolymerization initiator and a polymerizable double bond group is dissolved in advance in an organic solvent, or a photopolymerization initiator and a polymerizable double bond group are previously dissolved in an organic solvent. After dissolving a compound having a sensitizing dye and a sensitizing dye, an emulsion is prepared by the dispersion method described above, and an organic solvent is removed from the emulsion by distillation to prepare an underwater emulsion in which fine particles are dispersed in water. Is preferred. The organic solvent that can be used may be any organic solvent that is liquid at room temperature and can dissolve or disperse a compound having a polymerizable double bond group, a photopolymerization initiator, or a sensitizing dye. Examples of organic solvents include volatile organic solvents and non-volatile organic solvents. When a volatile organic solvent is used, it is preferably removed from the system by heating or leaving the volatile organic solvent from the produced dispersion. In the case of using a non-volatile organic solvent, the non-volatile organic solvent exhibits a flash point higher than 50 ° C., and the countermeasure as a dangerous substance may be reduced in normal handling, which is preferable.

  Specific examples of the volatile organic solvent include, for example, acetates of lower alkanols such as ethyl acetate, propyl acetate and butyl acetate, ethylene glycol acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate. , Ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, hydrocarbons such as hexane, cyclohexane and heptane, aromatics such as benzene, toluene and xylene, etc., and ethyl acetate is most preferably used.

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

  More preferably, the organic solvent used when preparing the emulsion in water is a volatile organic solvent. In this case, it is preferable because an underwater emulsion having the most stable dispersion state can be produced and the dispersion state can be kept stable even when exposed to a temperature higher than room temperature. As the volatile organic solvent, ethyl acetate is particularly preferable. Since ethyl acetate is highly volatile, it can be distilled off simply by placing it under heating or under reduced pressure. The emulsion in water after distillation of ethyl acetate is in a solid dispersion state and contains an organic solvent such as ethyl acetate. It is extremely preferable because it forms an aqueous coating solution that is more stable than the state. In the present invention, the aqueous coating solution means that water accounts for 50% by mass or more as a liquid medium component in the coating solution, and more preferably 80% by mass or more.

The photosensitive layer is preferably provided in the range of 0.2 to 5.0 g / m ² as a dry solid content. More preferably, it is the range of 0.5-3.0 g / m < ² >.

  Further, in the photosensitive lithographic printing plate used in the present invention, a protective layer is preferably provided on the photosensitive layer. The protective layer prevents exposure of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that hinder the image formation reaction caused by exposure in the photosensitive layer to further improve exposure sensitivity in the atmosphere. It has a favorable effect of improving. Furthermore, an effect of preventing the photosensitive layer surface from scratches is also expected. Therefore, the properties desired for such a protective layer are low permeability of low molecular weight compounds such as oxygen and excellent mechanical strength, and further, transmission of light used for exposure is not substantially inhibited, and the photopolymerizable photosensitive layer and It is desirable that it has excellent adhesiveness and can be easily removed in the development step after exposure.

  Such a device relating to the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic are used. Water-soluble polymers such as acids are known, and among these, using polyvinyl alcohol as a main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components.

The protective layer preferably has a dry solid content in the range of 0.1 to 10 g / m ² , and more preferably in the range of 0.1 to 3 g / m ² .

In the present invention, the above-described photosensitive lithographic printing plate is exposed imagewise. Light sources used for exposure include carbon arc, high pressure mercury lamp, ultra high pressure mercury lamp, low pressure mercury lamp, deep UV lamp, xenon lamp, metal halide lamp, tungsten lamp, halogen lamp, excimer UV lamp, LED lamp, various fluorescent lamps, etc. Lamp, black light, chemical light, etc.) can be used, but scanning exposure with a laser is very preferable in terms of plate making efficiency. Examples of the laser light source include a blue-violet semiconductor laser (violet laser), an argon laser, a helium / neon laser, a red LED, a near infrared laser, and an infrared laser. The scanning method may be any of an internal drum system, an external drum system, a planar scanning system, etc., but an internal drum system is preferred. The laser intensity at the plate surface is preferably set to 1~600μJ / cm ^2, particularly preferably in the 30~400μJ / cm ^2.

  The development method in the plate making method of the photosensitive lithographic printing plate of the present invention is preferably about 10 to 60 ° C., more preferably 15 to 45, by a known development method such as immersion development, spray development, brush development, and ultrasonic development. The temperature is about 5 ° C. and the time is about 5 seconds to 10 minutes. At that time, the protective layer provided as necessary on the photosensitive layer may be removed in advance with water or the like, or may be removed during development.

  In the present invention, the development method is not particularly limited, but the immersion development method is preferably used, and the time is preferably 5 to 300 seconds and the temperature is preferably 10 to 50 ° C.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited by this description. In addition, unless otherwise indicated,% and a part in the following description show mass ratio.

(Test 1)
Examples in which the processing solution used in the present invention is applied as a developing solution used during development will be described in detail.

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

<Hydrophilic layer coating solution>
Alkali-treated gelatin 1.2 parts Inorganic filler 1: Titanium dioxide 4.0 parts (SR-1 manufactured by Sakai Chemical Industry Co., Ltd., average primary particle diameter ≈ 0.3 μm,
Relative refractive index ≒ 2.04)
Inorganic filler 2: 1.6 parts of barium sulfate (manufactured by Sakai Chemical Industry Co., Ltd., Variace B-35, average primary particle size≈0.3 μm,
Relative refractive index ≒ 1.23)
Inorganic filler 3: 0.4 parts of aluminum hydroxide (Heidilite H-42, Showa Denko Co., Ltd., average primary particle size≈1.0 μm,
Relative refractive index ≒ 1.24)
Dispersant (acrylic acid copolymerized metal salt, 10% solution) 1.0 part Surfactant: 0.4 part of sodium polyoxyethylene lauryl ether acetate (Daiichi Kogyo Seiyaku Co., Ltd. Neo Haitenol (registered trademark) ECL- 45
10% solution)
Chelating agent: sodium triethylenetetramine hexaacetate 0.1 part Hardener (divinylsulfone, 5% solution) 4.0 part Adjust the pH to 7.0 with 1N sulfuric acid, and add 35 parts with water. did.

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

<Photopolymerizable photosensitive layer>
On the hydrophilic layer obtained above, the following photopolymerizable photosensitive layer coating solution was applied so that the solid content was 1.5 g / m ^2, and dried for 10 minutes in a 75 ° C. drier after coating. did.

<Photopolymerizable photosensitive layer coating solution>
Liquid compositions A and B having the following compositions were prepared.
<Liquid composition A>
300 parts of ion-exchanged water 20.0 parts of a polymer compound having a polymerizable double bond group (the following chemical formula 1 / weight average molecular weight 200,000)
Anionic surfactant (sodium dialkylsulfosuccinate) 5.0 parts (Perex (registered trademark) OT-P manufactured by Kao Corporation)
Colorant (Pigment Blue 15) 0.2 part

<Liquid composition B>
Low molecular weight compound having a polymerizable double bond group 6.0 parts (trimethylolpropane triacrylate)
Photopolymerization initiator 1 (Chemical formula 2 below) 2.0 parts Photopolymerization initiator 2 (Chemical formula 3 below) 1.5 parts 3-acryloxypropyltrimethoxysilane 0.5 parts Sensitizing dye (Chemical formula 4 below) 0. 05 parts 200 parts of ethyl acetate was added and dissolved.

  Liquid composition A was put into a vacuum emulsification apparatus PVQ-1D (manufactured by Mizuho Kogyo Co., Ltd.) and the rotation speed of the homomixer was set to 5000 rpm. Then, liquid composition B was put into the vacuum emulsification apparatus and homogenized at room temperature. The mixer was stirred at high speed for 20 minutes to carry out emulsification dispersion. Thereafter, the inside of the vacuum emulsification apparatus is reduced in pressure using an aspirator, the temperature is raised to 50 ° C. under a reduced pressure condition of 20% of atmospheric pressure, and ethyl acetate is distilled off under reduced pressure to form a photopolymerizable photosensitive layer coating solution. did. From the amount of ethyl acetate collected in the cooler, it was confirmed that all the ethyl acetate used was distilled off from the emulsion in water.

<Protective layer>
A coating solution is prepared according to the following protective layer formulation, and applied to the photopolymerizable photosensitive layer so that the solid content is 1.5 g / m ^2. After coating, the coating solution is dried in a dryer at 75 ° C. for 10 minutes. A photosensitive lithographic printing plate was obtained.

<Protective layer prescription>
1 part of polyvinyl alcohol (Kuraray Co., Ltd. PVA-102)
Sodium polyoxyethylene nonylphenyl ether sulfate 0.4 parts (10% aqueous solution)
9 parts of ion exchange water

<Exposure / Development>
The photosensitive lithographic printing plate obtained above was exposed to a test chart image using a blue-violet semiconductor laser emitting at 405 nm (output: 120 mW) as an exposure light source and setting the plate surface exposure energy to 200 μJ / cm ² . Then, using the processing liquid shown below, it was immersed at 29 ° C. for 15 seconds, and the surface having the photopolymerized photosensitive layer / protective layer was rubbed and developed with cellulose sponge to obtain a lithographic printing plate.

<Processing liquid>
800g of water
1.5g ammonium dihydrogen phosphate
Citric acid 1.5g
10g polyoxyethylene alkyl ether
(BT-9 manufactured by Nippon Surfactant Co., Ltd.)
Glycerin (DG made by NOF Corporation) 30g
Antiseptic (Bio-Ace (registered trademark) manufactured by KAI Kasei Co., Ltd.) 0.2g
Defoamer (KM-7775, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.04g

<Processing liquid (A)>
After adding 0.01 g of Pitzkor V-7154 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. as a water-soluble polymer compound to the above treatment liquid, the pH was adjusted to 6.0 using sodium hydroxide, and the entire amount was added with water. The treatment liquid (A) was obtained by adjusting to 1 L.

<Processing liquid (B)>
A treatment liquid (B) was obtained in the same manner except that the amount of the water-soluble polymer compound added to the treatment liquid (A) was 0.1 g.

<Processing liquid (C)>
A treatment liquid (C) was obtained in the same manner except that the amount of the water-soluble polymer compound added to the treatment liquid (A) was 1.0 g.

<Treatment liquid (D)>
A treatment liquid (D) was obtained in the same manner except that the amount of the water-soluble polymer compound added to the treatment liquid (A) was 10.0 g.

<Treatment liquid (E)>
After adding 10.0 g of α-cyclodextrin as a water-soluble polymer compound to the treatment liquid, the pH is adjusted to 6.0 with sodium hydroxide and the total amount is adjusted to 1 L with water to obtain a treatment liquid (E). Obtained.

<Processing liquid (F)>
After adding 10.0 g of gum arabic (Arabic Coal SS manufactured by Sanei Pharmaceutical Co., Ltd.) as a water-soluble polymer compound to the treatment solution, the pH is adjusted to 6.0 using sodium hydroxide, and the total amount is adjusted to 1 L with water. It adjusted and the processing liquid (F) was obtained.

<Processing liquid (G)>
After 10.0 g of polyvinyl alcohol (PVA-117 manufactured by Kuraray Co., Ltd.) as a water-soluble polymer compound is added to the treatment liquid, the pH is adjusted to 6.0 using sodium hydroxide, and the total amount is adjusted to 1 L with water. Thus, a treatment liquid (G) was obtained.

<Treatment liquid (H)>
After 10.0 g of polyvinyl pyrrolidone K-30 as a water-soluble polymer compound is added to the treatment liquid, the pH is adjusted to 6.0 using sodium hydroxide, and the total amount is adjusted to 1 L with water. Treatment liquid (H) Got.

  After attaching the sebum component to the non-image part of the lithographic printing plate obtained in this manner for 5 seconds to adhere the sebum component, it is stored for 24 hours in a temperature of 35 ° C. and humidity of 85% RH. Printing evaluation was performed by the method shown.

<Printing evaluation>
The printing machine uses an offset sheet-fed printing machine Sprint 226 manufactured by Komori Corporation, the ink is New Champion (registered trademark) F gloss ink S manufactured by DIC Graphics, and the humidifier is SLM- manufactured by Mitsubishi Paper Industries Co., Ltd. OD50 was diluted to 2% with tap water and used. Pearl paper (registered trademark) manufactured by Mitsubishi Paper Industries Co., Ltd. was used as the printing paper. The start of printing is a method in which printing is started by feeding paper as usual after wetting the entire plate by rotating it 20 times without feeding paper while keeping the swim roller in contact with the plate cylinder on which the lithographic printing plate is mounted. I took it. After printing 1,000 sheets, the state of fingerprint smudges generated in the non-image area was visually observed and determined according to the following evaluation criteria.

<Fingerprint dirt evaluation criteria>
X: Fingerprint-like ink stains can be clearly observed in the non-image area.
Δ: Slight or part of fingerprint-like dirt can be observed in the non-image area.
○: Ink smear cannot be observed in the non-image area.

(Test 2)
Next, an example in which the processing liquid used in the present invention is applied as a plate surface processing liquid that is brought into contact with a planographic printing plate immediately after completion of development and completion of plate making will be described.

A test lithographic printing plate produced in the same manner as in Test 1 was exposed to a test chart image using a blue-violet semiconductor laser (output: 120 mW) that emits light at 405 nm as an exposure light source and a plate surface exposure energy of 200 μJ / cm ² . Then, it was immersed in tap water at 29 ° C. for 15 seconds, and the surface having the photopolymerizable photosensitive layer / protective layer was rubbed and developed with cellulose sponge to obtain a lithographic printing plate.

  The treatment liquids (A) to (H) soaked in cellulose sponge are uniformly applied to the surface of the obtained lithographic printing plate, and then applied to the non-image area of the obtained lithographic printing plate for 5 seconds. The finger was brought into close contact with the sebum component, and then stored under a temperature of 35 ° C. and a humidity of 85% RH for 24 hours, and printed and evaluated in the same manner as in Test 1.

  The results obtained in Test 1 and Test 2 are shown in Table 1.

  As is apparent from the results shown in Table 1, it is possible to provide a method for making a photosensitive lithographic printing plate in which fingerprint stains do not occur in non-image areas even when stored under high temperature and high humidity conditions.

Claims (1)

  The photosensitive lithographic printing plate is imagewise exposed after imagewise exposing a photosensitive lithographic printing plate having at least a hydrophilic layer on a support and a photosensitive layer containing a compound having a polymerizable double bond group on the hydrophilic layer. A plate making method of a photosensitive lithographic printing plate, characterized in that the plate is treated with a treatment solution containing a water-soluble polymer compound obtained by grafting polyvinyl pyrrolidone to polyvinyl alcohol before being subjected to printing.