JP2018205504A - Method for manufacturing photosensitive lithographic printing sheet - Google Patents

Abstract

To provide a method for manufacturing a photosensitive lithographic printing sheet good in ink receptivity and having no generation of ink stain at a non-image part or collapse of dots at a dot image part, even at printing re-initiation after stopping a printer once.SOLUTION: After a photosensitive lithographic printing sheet having at least a hydrophilic layer containing an inorganic filler of 60 mass% or more based on total solid component amount of the hydrophilic layer and a photosensitive layer containing a compound having a polymerizable double bond group on a plastic film supporter in this order is exposed with image-like, it is developed by a developer containing a nonionic surfactant having an ethylene oxy group and a propylene oxy group and no aryl group.SELECTED DRAWING: None

Description

  The present invention relates to a method for making a photosensitive lithographic printing plate having a hydrophilic layer containing an inorganic filler and a photosensitive layer containing a compound having a polymerizable double bond group in at least this order on a plastic film support.

  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. It is applied. 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 publications, as a method for improving developability, various anionic, cationic and nonionic surfactants, isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone are used in the developer. A method containing a water-soluble organic solvent such as alcohol is described. In addition, International Publication No. 2013/058197, Japanese Patent Application Laid-Open No. 2006-133642, and the like include polyoxyethylene alkyl ethers, polyoxyethylene Nonionic properties such as alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters, alkyl benzene sulfonates, alkyl naphthalene sulfonates , 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 possessed by the above-described photosensitive lithographic printing plate is described in the above-mentioned International Publication No. 2013/058197 pamphlet, Japanese Patent Application Laid-Open No. 2013-216080, Japanese Patent Application Laid-Open No. 2013-130697, and the like. Although a hydrophilic layer containing 60% by mass or more of an inorganic filler is preferably used with respect to the total solid content of the hydrophilic layer, it has been difficult to positively hydrophilicize the hydrophilic layer. For this reason, for example, once the printing machine is stopped and then reprinting is started, there may be a situation in which printing cannot be continued, such as ink smearing on the entire surface of the printing plate or meshing. It was strongly desired.

  On the other hand, as a method for preventing ink smear during printing on a lithographic printing plate having an aluminum support, for example, JP-A-8-142534 (Patent Document 1) discloses a cationic surfactant, a nonionic surfactant and an amphoteric interface. A lithographic printing plate treating agent comprising an aqueous solution having a pH of 2.5 to 12.5 containing at least one surfactant selected from the group consisting of an activator and an acid or a buffer is disclosed in JP-A-2002-196507. In JP-A-2002-91015 and JP-A-2002-91015 (Patent Document 3), a photosensitive lithographic printing plate having a photosensitive layer made of a photopolymerizable photosensitive composition is image-exposed and then an inorganic alkali agent is used. And a developer containing a nonionic surfactant having a polyoxyalkylene ether group is disclosed in JP-A-2006-208877 (Patent Document 4). Developer containing a compound having discloses respectively.

JP-A-8-142534 JP 2002-196507 A JP 2002-91015 A JP 2006-208877 A

  The object of the present invention is to provide photosensitive lithographic printing that has good ink deposition and does not cause ink smudges in the non-image areas and halftone dots in the halftone image areas even at the start of reprinting after the printing press is stopped. It is to provide a plate making method.

  The above-mentioned problem of the present invention includes a compound having a hydrophilic layer containing an inorganic filler of 60% by mass or more based on the total solid content of the hydrophilic layer and a polymerizable double bond group on the plastic film support. A photosensitive lithographic printing plate having at least one photosensitive layer in this order, imagewise exposed, and then containing at least one nonionic surfactant having an ethyleneoxy group and a propyleneoxy group, and having no aryl group This can be achieved by a plate making method of a photosensitive lithographic printing plate characterized by developing with a developing solution.

  According to the present invention, a photosensitive lithographic plate having good ink deposition in the image area and causing no ink smear in the non-image area or halftone dot image area even at the start of reprinting after the printing machine is temporarily stopped. A printing plate making method can be provided.

  The nonionic surfactant having an ethyleneoxy group and a propyleneoxy group and having no aryl group contained in the developer used in the plate making method of the present invention is commercially available from NOF Corporation. Examples include Pronon (registered trademark) # 104, Pronon # 201, Pronon # 202B, Pronon # 204, UniLube (registered trademark) 70DP-600B, and the like. In the present invention, the content of the nonionic surfactant in the developing solution is not particularly limited, but it is possible to obtain a high effect by preferably containing 10 g / L or more in the working solution. The upper limit is preferably 100 g / L.

  Further, the developer used in the plate making method of the photosensitive lithographic printing plate of the present invention includes polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, polyoxyethylene oleyl ether, polyoxyethylene in addition to the nonionic surfactant described above. It may also contain one or more nonionic surfactants such as ether types such as oxyethylene stearyl ether, ester types such as polyoxyethylene monolaurate, polyoxyethylene monostearate and polyoxyethylene monooleate. it can. The addition amount is preferably 1 to 100 g / L, more preferably 5 to 50 g / L, depending on the use solution. If the amount added is less than this, the action of the nonionic surfactant having the ethyleneoxy group and propyleneoxy group and not having an aryl group may be insufficient. In some cases, the ink deposition property of the image portion is inferior.

  The developer used in the plate making method of the photosensitive lithographic printing plate of the present invention preferably contains water as a solvent and further contains a high-boiling water-soluble organic solvent. The high-boiling water-soluble organic solvent can more effectively prevent ink stains by enhancing the moisturizing effect of the non-image area. As the high boiling point organic solvent, it is preferable to use a polyol compound or a glycol derivative. Examples of the polyol compound include ethylene glycol, trimethylene glycol, propylene glycol, 1,3-butylene glycol, hexylene glycol and the like. Examples of the glycol derivative include diethylene glycol, triethylene glycol, glycerin, polyethylene glycol (molecular weight 200 to 600), dipropylene glycol, tripropylene glycol, and a copolymer of ethylene oxide and propylene oxide. Further, alkyl ethers of these compounds such as methyl, ethyl, propyl and butyl can be mentioned. The content of these high-boiling water-soluble organic solvents is preferably 1 to 200 g / L, more preferably 5 to 100 g / L, depending on the liquid used.

  The pH of the developer used in the plate making method of the photosensitive lithographic printing plate of the present invention is preferably 4.5 to 7.5, more preferably 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.

  Furthermore, the developer used in the plate making method of the photosensitive lithographic printing plate of the present invention is, if necessary, hydrophilic polymer compounds such as polyacrylic acid, gum arabic, and carboxymethylcellulose, ethylenediaminetetraacetic acid, triethylenetetraminehexaacetic acid, etc. A chelating agent, a rust inhibitor such as diethanolamine and benzotriazole, a preservative such as a benzotriazole derivative and a 4-isothiazolin-3-one compound, and an antifoaming agent such as silicone and an alkylene glycol compound.

  Next, on the plastic film support used in the present invention, a hydrophilic layer containing an inorganic filler of 60% by mass or more based on the total solid content of the hydrophilic layer and a compound having a polymerizable double bond group are contained. A photosensitive lithographic printing plate having at least a photosensitive layer in this order will be described.

  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.

  The hydrophilic layer contains 60% by mass or more of an inorganic filler with respect to the total solid content of the hydrophilic layer. Examples of the inorganic filler include calcium carbonate, magnesium carbonate, zinc oxide, titanium dioxide, barium sulfate, aluminum hydroxide, zinc hydroxide, colloidal silica, fine 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. Thereby, a photosensitive lithographic printing plate particularly excellent in stain resistance can be obtained.

  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. The addition amount of the inorganic filler is more preferably 70% by mass or more based on the total solid content of the hydrophilic layer.

  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 sulfates, fatty acid alkylbetaine amphoteric surfactants such as coconut oil fatty acid amidopropyl betaine, lauric acid amidopropyl betaine, myristic acid amidopropyl betaine, octanoic acid amidopropyl betaine, lauryldimethylaminoacetic acid , Steari Alkylbetaine-type amphoteric surfactants such as dimethylaminoacetic acid, sulfobetaine-type amphoteric surfactants such as dodecylaminomethyldimethylsulfopropylbetaine, octadecylaminomethyldimethylsulfopropylbetaine, sodium lauroylglutamate, potassium lauroylglutamate, lauroylmethyl-β -Amino acid type amphoteric surfactants such as alanine, and amine oxide type amphoteric surfactants such as lauryldimethylamine N-oxide and oleyldimethylamine N-oxide can be contained.

  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-A No. 2012-203132, JP-A No. 2012-208152, JP-A No. 2012-208331, 2012-208332, 2013-20103 It can be used in the present invention. Although the specific example is shown below, it is not limited to these.

  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, etc., or acryloyl group, methacryloyl group Polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, etc. are also used in the same way as various oligomers introduced with That.

  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.

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

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

  Preferred specific examples of the organic boron salt that is a photopolymerization initiator are shown below.

  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 adduct of sodium lauryl ether sulfate, polyethylene oxide adduct of ammonium lauryl ether 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.

  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.

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. (white fluorescent lamp) 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. Among them, GaN having a wavelength region of 390 to 430 nm is preferably used from the viewpoint of productivity and image definition. The scanning method may be any of an internal drum system, an external drum system, a planar scanning system, etc., but an internal drum system is preferred. 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.

  The plate making method of the photosensitive lithographic printing plate of the present invention is a development process using a developer containing at least one nonionic surfactant having an ethyleneoxy group and a propyleneoxy group and having no aryl group. 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.

Example 1
<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, Sakai Chemical Industry Co., Ltd., average primary particle size≈0.3 μm, relative refractive index≈2.04)
Inorganic filler 2: 1.6 parts of barium sulfate (Variace B-35, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size≈0.3 μm, relative refractive index≈1.23)
Inorganic filler 3: 0.4 part of aluminum hydroxide (Hijilite H-42, manufactured by Showa Denko KK, average primary particle size ≈ 1.0 μm, relative refractive index ≈ 1.24)
Dispersant (acrylic acid copolymerized metal salt, 10% solution) 1.0 part Surfactant: 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 by weight with water. It was.

  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 Polymer compound having a polymerizable double bond group (1-2 / weight average molecular weight 200,000)
20.0 parts 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>
Trimethylolpropane triacrylate 6.0 parts Photopolymerization initiator (3-2) 2.0 parts Trihaloalkyl-substituted compound (2-10) 1.5 parts 3-acryloxypropyltrimethoxysilane 0.5 parts Sensitizing dye (Chemical formula 4) 0.05 part 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>
Polyvinyl alcohol PVA-102 (manufactured by Kuraray Co., Ltd.) 1 part Surfactant (POE nonylphenyl ether sulfate, 10% solution) 0.4 part Ion-exchanged water 9 parts

<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 developer shown below, it was immersed 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 following developers (a) to (f) were used.
<Developer (a)>
Ammonium dihydrogen phosphate 1.5 g / L
Trisodium citrate 1.5g / L
Polyoxyethylene alkyl ether 10g / L
(Nippon Surfactant Industries, BT-9)
Polyoxyethylene polyoxypropylene glycol 12.5g / L
(Manufactured by NOF Corporation, Pronon # 104)
Glycerin (manufactured by NOF Corporation, DG) 30 g / L
Preservative (manufactured by Kay Kasei Co., Ltd., Bioace (registered trademark)) 0.2 g / L
Defoamer (manufactured by Shin-Etsu Chemical Co., Ltd., KM-7752) 0.04 g / L
The total amount was adjusted to 1 L with water. The pH was 5.5.

<Developer (b)>
A developer (b) was prepared in the same manner except that polyoxyethylene polyoxypropylene glycol in the developer (a) was changed to Pronon # 202B manufactured by NOF Corporation. The pH was 6.5.
<Developer (c)>
A developer (c) was prepared in the same manner except that the amount of polyoxyethylene polyoxypropylene glycol added to the developer (b) was 5 g / L. The pH was 6.5.
<Developer (d)>
A developer (d) was prepared in the same manner except that the amount of polyoxyethylene polyoxypropylene glycol added to the developer (b) was 50 g / L. The pH was 6.5.
<Developer (e)>
A developer (e) was prepared in the same manner except that the polyoxyethylene polyoxypropylene glycol was removed from the developer (a). The pH was 6.5.
<Developer (f)>
The polyoxyethylene polyoxypropylene glycol in the developer (a) was changed to NISSAN TRAX (registered trademark) K-300 (polyoxyethylene lauryl ether sulfate sodium salt, anionic surfactant) manufactured by NOF Corporation. Was similarly used as the developer (f). The pH was 6.9.

  The lithographic printing plate thus obtained was subjected to printing evaluation by the following method.

<Printing evaluation>
The printing machine uses an offset sheet-fed printing press RYOBI3200CCD (manufactured by Ryobi MHI Graphic Technology Co., Ltd.), the ink is DIC Corporation's New Champion (registered trademark) F gloss ink S, and the dampening liquid is SLM-OD ( A 10% diluted solution (manufactured by Mitsubishi Paper Industries Co., Ltd.) was used, and Pearl Coat (registered trademark) (manufactured by Mitsubishi Paper Industries Co., Ltd.) was used as the paper. The printing was started by rotating 20 times without feeding the paper while keeping the swim roller in contact with the plate cylinder, moistening the entire plate, and then feeding the paper as usual to start printing. After starting printing, after the 1,000 sheets have been printed, the printing press is temporarily stopped and left for 30 minutes in a state where the ink form roller and the water form roller are not in contact with the plate surface, and then printing is restarted in the same manner as at the start of printing. I let you. After the start of printing, the ink-filled state of the 100th image area, and the non-image area of the 100th sheet after restarting, and the entangled state of the halftone dots were visually observed, and the following evaluation criteria were used. Determined.

<Ink attachment evaluation criteria>
X: Ink imperfection defect can be confirmed not only in the fine image area but also in the solid image area. Δ: Almost no problem, but slight ink imperfection defect can be confirmed in the minute image area. Print dirt evaluation criteria>
×: Both ink stains in the non-image area and halftone dots in the halftone image area can be confirmed. Δ: There is no ink stain in the nonimage area, but halftone dots in the halftone image area can be confirmed. No entanglement in halftone image part

  As can be seen from the results shown in Table 1, according to the present invention, the ink is satisfactorily adhered, and even at the start of printing after the printing press is temporarily stopped, the ink stains in the non-image area and the half-tone image area are entangled. It is possible to provide a plate making method of a photosensitive lithographic printing plate in which no occurrence occurs.

Claims (1)

  On the plastic film support, a hydrophilic layer containing 60% by mass or more of an inorganic filler and a photosensitive layer containing a compound having a polymerizable double bond group based on the total solid content of the hydrophilic layer are at least in this order. The photosensitive lithographic printing plate having imagewise exposure is then developed with a developer containing at least one nonionic surfactant having an ethyleneoxy group and a propyleneoxy group and not having an aryl group. A process for making a photosensitive lithographic printing plate characterized by