JP2010197651A - Photosensitive lithographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate material which has excellent resistance to wear, prevents print contamination to be caused by scratches and fingerprints on the surface of the hydrophilic layer, and is improved in the adaptability of a cleaner liquid, with respect to the water-developable photosensitive lithographic printing plate material in which a hydrophilic layer and a photopolymerizable photosensitive layer are layered in this order on a plastic film substrate. <P>SOLUTION: The photosensitive lithographic printing plate material includes a hydrophilic layer and a photopolymerizable photosensitive layer containing a water-soluble polymer, successively formed on a plastic film substrate, wherein the hydrophilic layer contains silicone-based organic fine particles and water glass. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive lithographic printing plate material in which a hydrophilic layer and a photopolymerizable photosensitive layer are laminated in this order on a plastic film support, and a photosensitive lithographic plate using the photopolymerizable photosensitive layer that can be developed with water. It relates to printing plate materials. In particular, the present invention relates to a photosensitive lithographic printing plate material capable of image formation by a computer-to-plate (CTP) method. More specifically, the present invention relates to a photosensitive lithographic printing plate material using a plastic film that can form an image by water development using a scanning exposure apparatus that uses a light source such as a semiconductor laser that emits light at a wavelength of about 830 nm or 405 nm.

  In recent years, computer-to-plate (CTP) technology has been developed to output directly on a printing plate without outputting it on film based on digital data produced on a computer, and various types equipped with various lasers as output machines. Plate setters and photosensitive lithographic printing plate materials that match these are being actively developed. Important problems or requests that have been raised with the spread of the CTP method include various points related to development processing. In the normal CTP, the printing plate material is exposed to a laser image, and then the non-image area is eluted with an alkaline developer, and is subjected to printing through a water washing and gumming process. Alkaline developer is harmful to the human body, and its care and management are required for its handling and storage. Furthermore, the purchase cost and the cost related to waste liquid treatment impose a great burden on the user, and in addition, the pH, temperature, etc. must be carefully managed as the liquidity of the alkaline developer. Handling is complicated and it is always difficult to obtain reproducible results in the plate making process.

  There has been proposed a photosensitive lithographic printing plate material that avoids the use of such an alkaline developer and can be developed with water. For example, JP 2003-215801 A (Patent Document 1), JP 2008-265297 A (Patent Document 2), JP 2008-230205 A (Patent Document 3), JP 2008-238506 A, JP As shown in Japanese Patent Application Laid-Open No. 2008-250195 (Patent Document 4) and the like, a plastic film support provided with a hydrophilic layer is used, and a photocurable photosensitive layer that can be developed with water is provided thereon. A sex lithographic printing plate material has been proposed.

  In these photosensitive lithographic printing plate materials that can be developed with water, the development process is characterized and advantageous in that it is carried out only with water without using chemicals. Essential improvements in sex are required. That is, when an alkaline developer is used, good developability can be obtained by optimizing parameters such as the type, concentration and pH of the alkaline component in the alkaline developer in a manner that matches the developability of the photopolymerizable photosensitive layer. A printing plate material that is expressed and has a printing durability with no soiling is provided. However, in the case of water development, since the development is performed with water that does not substantially contain such an alkali component, the hydrophilic layer has good developability with respect to water and adheres to the photopolymerizable photosensitive layer. It must be adjusted from the material aspect to ensure sufficient properties.

  However, conventionally known hydrophilic layers do not always have sufficient adhesion between the photopolymerizable photosensitive layer having good developability in water and the hydrophilic layer, and printing is performed during or after water development. Due to the handling of the printing plate during the period until the printing is performed, there is a problem that fingerprint marks and rubbing marks remain on the non-image area (exposed hydrophilic layer surface) and appear as stains when printed. In particular, fingerprint marks are prominently displayed on a printed matter when the period from development to printing is long (hereinafter sometimes referred to as a plate).

  Furthermore, when background stains occur due to various causes during printing, printing may be interrupted once, the printing plate surface may be washed with a cleaner liquid, and printing may be started again. In such a case, when the suitability of the hydrophilic layer provided on the printing plate surface with respect to the cleaner liquid is inferior, there has been a problem that a portion wiped with the cleaner liquid appears as a stain on the printed matter.

JP 2003-215801 A JP 2008-265297 A JP 2008-230205 A JP 2008-250195 A

  A photosensitive lithographic printing plate material that can be developed with water, in which a hydrophilic layer and a photopolymerizable photosensitive layer are laminated in this order on a plastic film support, has excellent printing durability, scratches on the surface of the hydrophilic layer, and It is an object of the present invention to provide a photosensitive lithographic printing plate material in which printing stains derived from fingerprints are prevented and cleaner liquid suitability is improved.

  In a photosensitive lithographic printing plate material in which a hydrophilic layer and a photopolymerizable photosensitive layer that can be developed with water are provided in this order on a plastic film support, the hydrophilic layer contains a silicone-based organic fine particle and water glass. The problem relating to the present invention is basically solved by the lithographic printing plate material.

  It is possible to provide a photosensitive lithographic printing plate material that can be developed with water, has excellent printing durability, prevents printing stains due to scratches and fingerprints on the hydrophilic layer surface, and has improved cleaner liquid suitability. .

  First, the hydrophilic layer of the photosensitive lithographic printing plate material of the present invention, the silicone-based organic fine particles and water glass contained therein will be described.

  The silicone-based organic fine particles used in the present invention are those in which a silicone-based organic polymer having a structure in which silicon atoms and oxygen atoms are repeatedly connected by siloxane bonds shows the shape of the fine particles. Such silicone organic fine particles are preferably spherical and have an average particle diameter (diameter) in the range of 0.1 to 20 μm. Particularly preferable silicone-based organic fine particles that can be used in the present invention include materials having various particle diameters that are commercially available from Momentive Performance Materials Japan GK under the trade name Tospearl. By including these silicone organic fine particles in the hydrophilic layer related to the present invention described later, it is possible to remarkably prevent the generation of scratches and the occurrence of printing stains in combination with water glass described later. It is a feature. It also has the effect of preventing the occurrence of fingerprint trace stains associated with the plate and improving the suitability of the cleaner liquid.

  There is a preferred range for the amount contained in the hydrophilic layer of the silicone-based organic fine particles used in the present invention. Since there is a preferable range for the thickness of the hydrophilic layer itself, which will be described later, the preferable amount contained in the silicone-based organic fine particles is selected in the range of 0.01 g to 0.5 g per square meter. When it is applied in the range of 0.5 g to 20 g per square meter, the preferred amount of the silicone-based organic fine particles is most preferably in the range of 0.01 g to 0.2 g per square meter. In that case, the particle diameter of the silicone-based organic fine particles is also preferably in the range of 0.5 to 10 μm. With such a combination of the content and the particle diameter, the silicone-based organic fine particles are formed on the surface of the hydrophilic layer. It is most preferable that the surface of the film is exposed to an appropriate level, thereby improving the slipperiness of the surface and most effectively exerting the effect of preventing scratches and printing stains, which are one of the effects of the present invention.

  In the present invention, the silicone-based organic fine particles are contained in a hydrophilic layer together with water glass, so that it is possible to prevent the above-described scratches and effectively prevent smears during printing due to fingerprint marks. The action of the silicone-based organic fine particles is mainly to prevent scratches by improving the slipperiness of the surface, but the addition of water glass increases the effect and further prevents fingerprint stains or improves the suitability for the cleaner liquid described later. Demonstrate the effect. Conversely, even if water glass is added alone to the hydrophilic layer and used, all of these effects are not exhibited, and both exhibit synergistic and favorable effects.

In the present invention, water glass refers to an aqueous solution of sodium silicate, not an aqueous solution of a single compound, but a solution in which anhydrous silicic acid (SiO ₂ ) and sodium oxide (Na ₂ O) are mixed in various proportions. As a commercially available water glass, if the molar ratio of the _two is 1, Na ₂ O is 1, SiO ₂ is in the range of 2 to 4. When water is evaporated from the water glass, a solid material having a water content of about 10 to 30%, which is difficult to break, and having elasticity, is formed, and functions as a binder having adhesiveness. In some cases, K ₂ O may be partially contained instead of Na ₂ O, but even in this case, the molar ratio with SiO ₂ is preferably in the above range.

  There is a preferred range for the amount contained in the hydrophilic layer of the water glass used in the present invention. Since there is a preferable range for the thickness of the hydrophilic layer itself described later, the preferable dry solid content mass contained in the water glass is selected from the range of 0.05 g to 5 g per square meter. When coated in a mass of 0.5 g to 20 g per square meter, the preferred dry solid mass of the water glass is most preferably in the range of 0.05 g to 3 g per square meter.

  In the present invention, when the water glass and the above-mentioned silicone-based organic fine particles are used in combination, there is a preferred ratio of both, and the silicone-based organic fine particles are 0.1 to 100 parts by weight of the dry glass in terms of dry solid content. It is preferably in the range of 50 parts by mass, more preferably in the range of 1 to 30 parts by mass.

  Since water glass is a strong alkaline aqueous solution, when it is contained in the hydrophilic layer, it is preferably used by adjusting to an appropriate pH, such as neutralizing with an appropriate acid. In the present invention, it is particularly preferable to use water glass with phosphoric acid adjusted to a pH of 2 to 9 with phosphoric acid. By using water glass in this pH range, the pH of the hydrophilic layer itself is adjusted to the same range, thereby improving the adhesiveness with the photopolymerizable photosensitive layer described later and improving the printing durability. preferable.

  In the present invention, it is also preferable to add various anionic surfactants to the hydrophilic layer as necessary. Examples of the anionic surfactant that can be used in the present invention include higher fatty acid salts such as sodium laurate, sodium stearate, and sodium oleate, alkyl sulfates such as sodium dioctylsulfosuccinate, sodium lauryl sulfate, and sodium stearyl sulfate. High alcohol alcohol sulfates such as sodium octyl alcohol sulfate, sodium lauryl alcohol sulfate, ammonium lauryl alcohol sulfate, aliphatic alcohol sulfates such as sodium acetyl alcohol sulfate, alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate Alkyl naphthalenes such as sodium butyl naphthalene sulfonate and sodium isopropyl naphthalene sulfonate Sulfonates, alkyl diphenyl ether disulfonates such as sodium alkyl diphenyl ether disulfonate, alkyl phosphate esters such as sodium lauryl phosphate, sodium stearyl phosphate, polyethylene oxide adduct of sodium lauryl ether sulfate, polyethylene oxide adduct of lauryl ether ammonium sulfate, Polyethylene oxide adducts of alkyl ether sulfate such as polyethylene oxide adduct of lauryl ether sulfate triethanolamine, polyethylene oxide adducts of alkyl phenyl ether sulfate such as polyethylene oxide adduct of sodium nonylphenyl ether sulfate, lauryl ether Alkyl ether phosphoric acid such as polyethylene oxide adduct of sodium phosphate It may be mentioned polyethylene oxide adducts, polyethylene oxide adducts of alkyl phenyl ether phosphate salts of polyethylene oxide adducts of nonyl phenyl ether sodium phosphate and the like. Of these, alkyl naphthalene sulfonates and alkyl sulfates such as sodium dioctyl sulfosuccinate have the most remarkable effect of preventing printing stains and can be preferably used.

  When an anionic surfactant is used in the present invention, there is a preferred range for the amount contained in the hydrophilic layer. Since there is a preferable range with respect to the thickness of the hydrophilic layer itself, which will be described later, the preferable amount of the anionic surfactant contained is selected in the range of 0.01 g to 0.5 g per square meter. When applied in the dry mass range of 0.5 g to 20 g per square meter, the preferred amount of the anionic surfactant is most preferably in the range of 0.01 g to 0.3 g per square meter.

  The hydrophilic layer of the present invention preferably contains colloidal silica. The colloidal silica referred to herein is various in a spherical shape, a needle shape, an irregular shape, or a necklace shape in which spherical particles are connected, preferably having an average particle diameter of 5 to 200 nm measured by a light scattering particle size distribution analyzer. A silica sol having a shape and a particle diameter and stably dispersed in water is preferably used. As such materials, various colloidal silicas are provided, for example, under the name of Snowtex from Nissan Chemical Industries, Ltd., and as a spherical silica sol, Snowtex XS (particle diameter 4 to 6 nm), Snowtex S (particle diameter 8) To 11 nm), Snowtex 20 (particle size 10 to 20 nm), Snowtex XL (particle size 40 to 60 nm), Snowtex YL (particle size 50 to 80 nm), Snowtex ZL (particle size 70 to 100 nm), Snowtex As an acidic type silica sol from which MP-2040 (particle diameter 200 nm) and sodium salt on the surface are removed, SNOWTEX OXS, OS and the like can be preferably used. Examples of the needle-like or amorphous silica sol include Snowtex UP, OUP, and Fine Cataloid F-120 available from Catalyst Kasei Kogyo Co., Ltd. Examples of the necklace-shaped silica sol include Snowtex PS-S (particle diameter 80 to 120 nm), PS-M (particle diameter 80 to 150 nm), and PS-SO and PS-MO which are acidic types thereof. Among these, a necklace-like silica sol is particularly preferable, and it has an effect of improving adhesion with a photocurable photosensitive layer described later, improving printing durability, and preventing the occurrence of printing stains, and can be used very preferably. .

  As such colloidal silica preferably contained in the hydrophilic layer according to the present invention, each type of colloidal silica may be used alone, or different types of colloidal silica may be mixed and used in various proportions. In particular, by using the above-mentioned necklace-like silica and spherical colloidal silica of various particle diameters in combination with this, the coating strength of the hydrophilic layer is increased, and printing stains on non-image areas are prevented under printing conditions. An effective and preferred system is obtained.

  In the present invention, when the above-mentioned colloidal silica is used in the hydrophilic layer, there is a preferred range for the amount of colloidal silica added. When the dry solid content mass of the water glass contained in the hydrophilic layer is 1 part, the dry solid content mass of the colloidal silica is preferably in the range of 50 parts or less, and the colloidal silica is included beyond this. In some cases, the effect of adding water glass is not observed.

  As described above, there is a preferable range for the dry solid content coating amount of the hydrophilic layer containing the silicone-based organic fine particles, water glass and an anionic surfactant or colloidal silica which may be added as necessary. It is preferable to form a dry mass on the body in the range of 0.5g to 20g per square meter. If it is less than this range, printing stains are likely to occur during printing, and more than 20g per square meter is applied. In such a case, the coating film may be easily cracked. The most preferred range is from 1 g to 10 g per square meter. The hydrophilic layer is coated and dried on the support using various known coating methods.

  In the present invention, the hydrophilic layer preferably further contains a water-soluble polymer and a crosslinking agent in addition to the various elements as described above. The water-soluble polymer is preferably one that forms a system that does not cause mutual aggregation and maintains a uniform solution state when mixed with the above water glass. Most preferably, the glass and the water-soluble polymer do not cause phase separation, form a uniform film, and form a system that does not cause a phase separation structure. In order to realize this, it is preferable that the coating material consisting only of water glass and the water-soluble polymer is transparent in appearance or slightly translucent and translucent, and is an opaque hydrophilic layer that is completely phase-separated and clouded. Is not preferred in the present invention. Furthermore, the surface shape is preferably uniform, and a combination of water glass and a water-soluble polymer that causes roughening is not preferable. It is essential for water-soluble polymers to prevent the occurrence of cracks caused by water glass and to prevent the ingress of ink during printing by filling the gaps caused by cracks. Can be used.

  Examples of water-soluble polymers that can be used in the present invention include polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol, modified starch, and modified cellulose. Furthermore, the most preferable water-soluble polymer includes a polymer represented by the following general formula I.

  In the above formula, X represents mass% of the repeating unit in the copolymer composition, and represents any numerical value from 1 to 40. The repeating unit A represents a repeating unit having a group selected from a carboxyl group, an amino group, a hydroxyl group, and an acetoacetoxy group as a reactive group. The repeating unit B represents a repeating unit having a hydrophilic group necessary for making the copolymer water-soluble.

  The water-soluble polymer represented by the above general formula I contains a reactive group in the molecule for allowing a crosslinking reaction to proceed efficiently with a crosslinking agent described later. As the reactive group, a carboxyl group, An amino group, a hydroxyl group, and an acetoacetoxy group. In order to obtain a water-soluble polymer having such a reactive group in the molecule, it is preferable to incorporate various monomers having a reactive group in a copolymerized form. Examples of the monomer corresponding to the repeating unit A represented by the general formula I include acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid, cinnamic acid, maleic acid. Carboxyl group-containing monomers such as acid monoalkyl esters, fumaric acid monoalkyl esters, 4-carboxystyrene, acrylamide-N-glycolic acid and their salts, allylamine, diallylamine, 2-dimethylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate 2-diethylaminoethyl acrylate, 2-diethylaminoethyl methacrylate, 3-dimethylaminopropyl acrylamide, 3-dimethylaminopropyl methacrylamide, 4-aminostyrene Amino group-containing monomers such as 4-aminomethylstyrene, N, N-dimethyl-N- (4-vinylbenzyl) amine, N, N-diethyl-N- (4-vinylbenzyl) amine, 4-vinylpyridine, 2 Nitrogen-containing heterocycle-containing monomers such as vinylpyridine and N-vinylimidazole, (meth) acrylamides such as N-methylolacrylamide and 4-hydroxyphenylacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxy Examples thereof include hydroxyalkyl (meth) acrylates such as propyl acrylate, 2-hydroxypropyl methacrylate, and glycerol monomethacrylate, and acetoacetoxyethyl methacrylate, but are not limited to these examples.

  In the above general formula I, the ratio X in the copolymer of the repeating unit A is in the range of 1 to 40, and if it is less than this range, the water resistance cannot be exhibited even if the crosslinking reaction proceeds. If it exceeds the range, the effect of introduction of the repeating unit B for imparting water solubility described below is weakened, and the affinity of the hydrophilic layer for water may decrease.

  Furthermore, as the monomer for giving the repeating unit B in the general formula I, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylate, 3-sulfopropyl methacrylate, 2-acrylamide- Sulfo group-containing monomers such as 2-methylpropane sulfonic acid and salts thereof, phosphate group-containing monomers such as vinylphosphonic acid and salts thereof, dimethyldiallylammonium chloride, acrylic acid 2- (trimethylammonium chloride) ethyl ester, methacryl Acid 2- (trimethylammonium chloride) ethyl ester, acrylic acid 2- (triethylammonium chloride) ethyl ester, methacrylic acid 2- (triethylammonium chloride) ethyl ester, Quaternary ammonium salts such as 3-acrylamidopropyl) trimethylammonium chloride, N, N, N-trimethyl-N- (4-vinylbenzyl) ammonium chloride, acrylamide, methacrylamide, N, N-dimethylacrylamide, N, N- Alkyleneoxy groups such as (meth) acrylamides such as dimethylmethacrylamide, N, N-diethylacrylamide, N-isopropylmethacrylamide, methoxydiethylene glycol monoester methacrylate, methoxypolyethylene glycol monoester methacrylate, polypropylene glycol monoester methacrylate Examples thereof include, but are not limited to, containing (meth) acrylates, N-vinylpyrrolidone, and N-vinylcaprolactam. These water-soluble monomers may be used alone to constitute the repeating unit A, or any two or more kinds may be used. Examples of preferred water-soluble polymers according to the present invention are shown below.

  When such a water-soluble polymer is used, there is a preferred range in relation to water glass, and when the dry solid mass of the water glass is 1 part, the dry solid content mass ratio of the water-soluble polymer is 20 parts or less. A range is preferable. When the water-soluble polymer is contained in the hydrophilic layer at a ratio exceeding this, the adhesiveness with the photopolymerizable photosensitive layer described later is lowered, and the printing durability may be lowered during printing.

  It is preferable to include a cross-linking agent for adding to the hydrophilic layer according to the present invention to cross-link the water-soluble polymer. Examples of the crosslinking agent used for such purposes include various known compounds. Specific examples include epoxy compounds, aziridine compounds, oxazoline compounds, isocyanate compounds and derivatives thereof, aldehyde compounds such as formalin, methylol compounds, and hydrazide compounds. Hereinafter, specific examples of such crosslinking agents will be described with chemical formulas. Among these, an epoxy compound is a particularly preferable example.

  As the epoxy compound, a compound having two or more epoxy groups in the molecule and water-soluble is preferably used. These epoxy compounds are relatively stable in water under neutral to weakly acidic conditions, and when a coating liquid for forming a hydrophilic layer is prepared, the coating liquid has a long life and is extremely advantageous in continuous production. . Examples of preferred epoxy compounds are shown below.

  In order for the crosslinking reaction to proceed efficiently between the epoxy compound as described above and the water-soluble polymer, a carboxyl group or an amino group is particularly preferable as the reactive group contained in the water-soluble polymer.

  Examples of preferred compounds as aziridine compounds are shown below. In order for the crosslinking reaction to proceed efficiently between the aziridine compound and the water-soluble polymer, a carboxyl group is particularly preferable as the reactive group contained in the water-soluble polymer.

  As the oxazoline compound, a compound containing two or more groups represented by the following general formula as substituents in the molecule is preferable, and as various commercially available compounds, for example, various grades provided by Nippon Shokubai Co., Ltd. under the trade name Epocross These compounds are preferably used. In order for the crosslinking reaction to proceed efficiently between the oxazoline compound and the water-soluble polymer, a carboxyl group is particularly preferred as the reactive group contained in the water-soluble polymer.

  As the isocyanate compound, a compound that is stable in water is preferable, and a so-called self-emulsifiable isocyanate compound or a blocked isocyanate compound is preferably used. Examples of the self-emulsifying isocyanate compound include Japanese Patent Publication No. 55-7472 (U.S. Pat. No. 3,996,154) and Japanese Patent Laid-Open No. 5-222150 (U.S. Pat. No. 5,252,696). ), Self-emulsifiable isocyanate as described in JP-A-9-71720, JP-A-9-328654, JP-A-10-60073, and the like. Specifically, for example, a polyisocyanate having an isocyanurate structure of a cyclic trimer skeleton formed from an aliphatic or alicyclic diisocyanate in the molecule, or a polyisocyanate having a burette structure, a urethane structure or the like in the molecule. A very preferable example is a polyisocyanate compound having a structure obtained by adding a polyethylene glycol or the like having one terminal etherification to only a part of the polyisocyanate group as a base polyisocyanate. A method for synthesizing an isocyanate compound having such a structure is described in the above specification. Specific examples of such isocyanate compounds are commercially available in which polyisocyanates obtained by cyclic trimerization using hexamethylene diisocyanate or the like as a starting material are used as base polyisocyanates. For example, Duranate WB40 or WX1741 is available from Asahi Kasei Corporation. And so on. The blocked isocyanate compound is blocked with bisulfite, alcohols, lactams, oximes, active methylenes, etc. as seen in, for example, JP-A-4-184335 and JP-A-6-175252. Blocked isocyanate is preferably used. In order for the crosslinking reaction to proceed efficiently between the isocyanate compound and the water-soluble polymer, the reactive group contained in the water-soluble polymer is particularly preferably a hydroxyl group or an amino group.

  Examples of aldehyde compounds such as formalin and methylol compounds include formalin, glyoxal, and various N-methylol compounds as shown below. In order for the crosslinking reaction to proceed efficiently between such a compound and the water-soluble polymer, the reactive group contained in the water-soluble polymer is particularly preferably a hydroxyl group or an amino group.

  Examples of compounds that can be preferably used as hydrazide compounds are shown below. In order for the crosslinking reaction to proceed efficiently between the hydrazide compound and the water-soluble polymer, an active methylene group such as an acetoacetoxy group is particularly preferable as the reactive group contained in the water-soluble polymer. .

  There is a preferred range for the ratio of the various cross-linking agents and the water-soluble polymer as described above. The crosslinking agent is preferably used in the range of 1 to 40 parts by mass with respect to 100 parts by mass of the water-soluble polymer.

  The support for forming the photosensitive lithographic printing plate material of the present invention is various plastic films, such as polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, cellulose diacetate, cellulose triacetate, Typical examples include cellulose propionate, cellulose butyrate, and cellulose nitrate, and polyethylene terephthalate and polyethylene naphthalate are particularly preferably used. These films are preferably subjected to hydrophilic treatment on the surface before providing the hydrophilic layer, and examples of such hydrophilic treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment. . An undercoat layer may be provided on the base material in order to enhance the adhesion to the hydrophilic layer provided on the base material as a further hydrophilic treatment. As the undercoat layer, a layer containing a hydrophilic resin as a main component is effective. Examples of hydrophilic resins include gelatin, gelatin derivatives (for example, phthalated gelatin), hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, ethyl hydroxyethyl cellulose, polyvinyl pyrrolidone, polyethylene oxide, xanthan, cationic hydroxyethyl cellulose, polyvinyl alcohol, A water-soluble resin such as polyacrylamide is preferred. Particularly preferred are gelatin and polyvinyl alcohol. As the undercoat layer, it is also preferable to provide an undercoat layer made of a hydrophilic resin such as gelatin as described above after providing an undercoat first layer using a latex such as vinylidene chloride. By forming the plastic film support and the hydrophilic layer through such an undercoat layer, printing durability under long run printing conditions over a large number of copies is preferably used.

  A water-soluble polymer as a binder is contained in the photopolymerizable photosensitive layer that can be developed with water according to the present invention. As such a water-soluble polymer, any polymer which is essentially water-soluble can be used. Examples thereof include polyacrylamide, polyvinyl pyrrolidone, poly (vinyl pyrrolidone-vinyl acetate) copolymer, polyvinyl alcohol. Modified starch, modified cellulose and the like can be used. Furthermore, it is possible to use a polymer represented by the general formula I.

  The water-soluble polymer contained in the photopolymerizable photosensitive layer in the invention is particularly preferably a water-soluble polymer having a polymerizable double bond group in the side chain. In this case, the polymerizable double bond group introduced into the side chain is preferably a vinyl double bond group such as an acryloyl group, a methacryloyl group, or a styryl group, or an allyl group. Specific methods for introducing these polymerizable double bond groups into the water-soluble polymer side chain are described in, for example, the method disclosed in Japanese Patent Application Laid-Open No. 2003-215801 (Patent Document 1) or in Examples described later. An example is the method.

  In order to show good solubility in water as the water-soluble polymer, the polymer preferably has an acidic group such as a carboxyl group, a sulfonic acid group, or a phosphoric acid group in the side chain. The acidic group is particularly preferably neutralized with an arbitrary base. Among these, a water-soluble polymer having a sulfonate group in the side chain exhibits the best water solubility, and a photopolymerizable photosensitive layer using the water-soluble polymer is particularly preferable because of good water developability.

  More preferable examples of the water-soluble polymer include water-soluble polymers having both a sulfonate group and a phenyl group having a vinyl group bonded via a linking group containing a hetero ring in the side chain. The phenyl group to which a vinyl group is bonded via a linking group containing a heterocycle has a group represented by the following general formula II in the side chain.

In the formula, Z represents a linking group having a heterocycle, and R ₁ , R ₂ and R ₃ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, and an alkyl group. An aryl group, an alkoxy group, an aryloxy group, and the like, and these groups may be substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, or the like. R ₄ represents a group or an atom capable of substituting for a hydrogen atom. n represents 0 or 1, m represents an integer of 0 to 4, and k represents an integer of 1 to 4. Examples of the heterocyclic group include a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, a tetrazole ring, an isoxazole ring, an oxazole ring, an oxadiazole ring, an isothiazole ring, a thiazole ring, a thiadiazole ring, a thiatriazole ring, and an indole ring. , Indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline ring, quinoxaline ring, etc. A nitrogen-containing heterocyclic ring, a furan ring, a thiophene ring, and the like, and a substituent may be bonded to these heterocyclic rings. Examples of the group represented by the general formula II are shown below, but are not limited to these examples.

Among the groups represented by the general formula II, preferred ones exist. That is, it is preferable that R ₁ and R ₂ are hydrogen atoms and R ₃ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.). Further, the linking group is preferably a linking group containing a thiadiazole ring, and k is preferably 1 or 2.

  The side chain having a sulfonate group simultaneously contained in the water-soluble polymer composition is preferably a sulfonate group bonded to the main chain via a linking group as shown in the following general formula III.

In the general formula III, the linking group L represents any atom or group that connects the main chain and the sulfonic acid group, and is preferably a group consisting of a combination of —COO— group, —CONH— group and alkylene group, arylene group, and the like. . Examples of the base B ⁺ that forms a salt with a sulfonic acid group include inorganic bases such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, various amines, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, choline, and the like. A quaternary ammonium base is preferably used.

  In the present invention, the water-soluble polymer contained in the photopolymerizable photosensitive layer is characterized by being water-soluble because it can be developed with water. There is a preferred range for the ratio of the acidic group such as carboxyl group, phosphoric acid group and sulfonic acid group to the polymerizable double bond group in the polymer composition. The repeating unit having an acidic group is preferably in the range of 40% by mass to 90% by mass in the polymer composition. When the amount is less than this, the polymer becomes insoluble in water and the water developability may be lowered. Moreover, when it exceeds 90 mass%, sufficient printing durability may not be obtained. In the present invention, by providing the photopolymerizable photosensitive layer containing the water-soluble polymer as described above on the hydrophilic layer containing the water glass and the silicone-based organic fine particles described above, it is possible to specifically prevent printing stain and It is the feature that it discovered that coexistence of printability was attained. As a mechanism, although an ionic interaction between an acidic group in a water-soluble polymer and a silanol group (particularly sodium salt) contained in water glass is considered, it is not clear.

There is a more preferred base as the base B ⁺ included as the sulfonate group represented by the general formula III above. It is a tertiary amine having a hydroxyl group, and specific examples include dimethylaminoethanol, diethylaminoethanol, triethanolamine, n-butyldiethanolamine, and t-butyldiethanolamine. By using a water-soluble polymer having these sulfonate groups using these bases, water developability of the water-soluble polymer becomes extremely good, which is extremely preferable for preventing the occurrence of printing stains.

  There is a preferred range for the molecular weight of the water-soluble polymer, and the weight average molecular weight is preferably in the range of 5000 to 500,000. If the molecular weight is less than this, the printing durability may be insufficient, and it exceeds 500,000. With the molecular weight, the viscosity of the coating liquid at the time of coating becomes too high, and uniform coating may be difficult. The most preferred molecular weight range is between tens of thousands and 500,000.

  In the water-soluble polymer composition having both the sulfonate group and a phenyl group having a vinyl group bonded via a linking group containing a hetero ring in the side chain, the sulfonate group and vinyl may be used depending on the purpose. Various repeating units can be introduced in addition to the repeating unit having a group. For example, as hydrophilic monomers, acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, itaconic acid, crotonic acid, maleic acid, fumaric acid, cinnamic acid, maleic acid monoalkyl ester, fumaric acid monoalkyl Carboxyl group-containing monomers such as esters, 4-carboxystyrene, acrylamide-N-glycolic acid and salts thereof, phosphate group-containing monomers such as vinylphosphonic acid and salts thereof, allylamine, diallylamine, 2-dimethylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl acrylate, 2-diethylaminoethyl methacrylate, 3-dimethylaminopropylacrylamide, 3-dimethylaminopropyl methacrylate Amino group-containing monomers such as amide, 4-aminostyrene, 4-aminomethylstyrene, N, N-dimethyl-N- (4-vinylbenzyl) amine, N, N-diethyl-N- (4-vinylbenzyl) amine And nitrogen-containing heterocycle-containing monomers such as quaternary ammonium salts, 4-vinylpyridine, 2-vinylpyridine, N-vinylimidazole, and N-vinylcarbazole, and quaternary ammonium salts thereof, acrylamide, methacrylamide, N, (Meth) acrylamides such as N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N-isopropylmethacrylamide, diacetoneacrylamide, N-methylolacrylamide, 4-hydroxyphenylacrylamide, 2- Hydroxy Hydroxyalkyl (meth) acrylates such as til acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, glycerol monomethacrylate, methacrylic acid methoxydiethylene glycol monoester, methacrylic acid methoxypolyethylene glycol monoester, methacrylic acid Examples include, but are not limited to, alkyleneoxy group-containing (meth) acrylates such as acid polypropylene glycol monoester, N-vinylpyrrolidone, and N-vinylcaprolactam. These water-soluble monomers may be used alone or in combination of any two or more.

  Alternatively, as a hydrophobic monomer, styrene derivatives such as styrene, 4-methylstyrene, 4-hydroxystyrene, 4-acetoxystyrene, 4-chloromethylstyrene, 4-methoxystyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate , N-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, alkyl (meth) acrylates such as dodecyl methacrylate, aryl (meth) acrylates such as phenyl methacrylate, benzyl methacrylate, or arylalkyl (meth) acrylates , Acrylonitrile, methacrylonitrile, phenylmaleimide, hydroxyphenylmaleimide, vinyl acetate, chlorovinegar Vinyl esters such as vinyl, vinyl propionate, vinyl butyrate, vinyl stearate and vinyl benzoate, vinyl ethers such as methyl vinyl ether and butyl vinyl ether, others, acryloylmorpholine, tetrahydrofurfuryl methacrylate, vinyl chloride, vinylidene chloride, allyl alcohol And various monomers such as vinyltrimethoxysilane and glycidyl methacrylate. As a water-soluble polymer in the present invention, a copolymer comprising any combination of these and a sulfonate group and a phenyl group having a vinyl group bonded via a linking group containing a hetero ring in a repeating unit at the same time. Can be used. When such a sulfonate group and a repeating unit other than a phenyl group to which a vinyl group is bonded via a linking group containing a heterocyclic ring are contained in the polymer, the proportion in the water-soluble polymer is 50% by mass. It is preferable to keep the ratio to less than or equal to%, and if it is introduced at a ratio exceeding this, it may hinder both the prevention of printing smudge and the printing durability, which are the object of the present invention.

  Although the example of the preferable water-soluble polymer in connection with this invention is shown below, it is not limited to these examples. In the formula, the number represents the mass% of each repeating unit in the polymer. Regarding the synthesis method of these polymers, it is easily synthesized by the same method as the synthesis example described in, for example, JP-A No. 2003-215801 (Patent Document 1).

  The photopolymerizable photosensitive layer according to the present invention contains a photopolymerization initiator together with the water-soluble polymer. As a photoinitiator used for this invention, arbitrary compounds can be used if it is a compound which can generate | occur | produce a radical by irradiation of light or an electron beam.

  Examples of photopolymerization initiators that can be used in the present invention include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, e) ketoxime ester compounds, (f) azinium compounds, (g) active ester compounds, (h) metallocene compounds, (i) trihaloalkyl-substituted compounds, and (j) organoboron compounds.

  (A) Preferred examples of aromatic ketones include compounds having a benzophenone skeleton or a thioxanthone skeleton described in “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” JPFOUASSIER, JFRABEK (1993), P. 77 to P. 177. Α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, α-substituted benzoin compounds described in JP-B-47-22326, and JP-B-47. Benzoin derivatives described in JP-A-236364, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, Benzoin ethers described in JP-A-62-181345 and JP-A-2-211452 P-di (dimethylaminobenzoyl) benzene, a thio-substituted aromatic ketone described in JP-A-61-194062, an acylphosphine sulfide described in JP-B-2-9597, and JP-B-2-9596 And the thioxanthones described in JP-B-63-61950 and the coumarins described in JP-B-59-42864.

  (B) Examples of aromatic onium salts include N, P, As, Sb, Bi, O, S, Se, Te, or I aromatic onium salts. Examples of such aromatic onium salts include compounds exemplified in Japanese Patent Publication No. 52-14277, Japanese Patent Publication No. 52-14278, Japanese Patent Publication No. 52-14279, and the like.

  (C) Examples of organic peroxides include almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. For example, 3,3 ′, 4,4′-tetra (tert-butyl) Peroxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-hexylperoxycarbonyl) benzophenone, 3, 3 ', 4,4'-tetra (tert-octylperoxycarbonyl) benzophenone, 3,3', 4,4'-tetra (cumylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra ( p-Isopropylcumylperoxycarbonyl) benzophenone, di-tert-butyldiperoxyisophthalate, etc. Tel systems are preferred.

  (D) Examples of hexaarylbiimidazole include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4. ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-bromophenyl) -4,4', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o, p -Dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole 2,2'-bis (o, o'-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl) -4,4', 5 , 5 ' Tetraphenylbiimidazole, 2,2'-bis (o-methylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-trifluoromethylphenyl) -4, Examples include 4 ', 5,5'-tetraphenylbiimidazole.

  (E) Examples of ketoxime esters include 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, 2-acetoxyiminopentane- 3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminobutan-2-one, 2- And ethoxycarbonyloxyimino-1-phenylpropan-1-one.

  Examples of (f) azinium salt compounds include JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, JP-B-46. The compound group which has NO bond as described in -42363 gazette etc. can be mentioned.

  (G) Examples of active ester compounds include imide sulfonate compounds described in JP-B-62-2623, etc., and active sulfonates described in JP-B-63-14340, JP-A-59-174831, etc. be able to.

  (H) Examples of metallocene compounds include JP-A-59-152396, JP-A-61-151197, JP-A-63-41484, JP-A-2-249, and JP-A-2-4705. And titanocene compounds described in JP-A-1-304453 and iron-arene complexes described in JP-A-1-152109. Specific titanocene compounds include, for example, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3. , 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti -Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2, 4-difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-T -Bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyr-1-yl) -phen-1-yl, etc. Can do.

  (I) Specific examples of the trihaloalkyl-substituted compound include compounds having at least one trihaloalkyl group such as a trichloromethyl group and a tribromomethyl group in the molecule. US Pat. No. 3,954,475 Specification, U.S. Pat. No. 3,987,037, U.S. Pat. No. 4,189,323, JP-A-61-151644, JP-A-63-298339, JP-A-4-69661 And trihalomethyl-s-triazine compounds described in JP-A-11-153859, JP-A-54-74728, JP-A-55-77742, JP-A-60-138539, 2-Trihalomethyl-1,3 described in JP-A-61-143748, JP-A-4-362644, JP-A-11-84649, etc. 4- oxadiazole derivatives. Moreover, the trihaloalkylsulfonyl compound as described in Unexamined-Japanese-Patent No. 2001-290271 etc. which this trihaloalkyl group couple | bonded with the aromatic ring or the nitrogen-containing heterocyclic ring through the sulfonyl group is mentioned.

  (J) Examples of the organic boron salt compound include JP-A-8-217813, JP-A-9-106242, JP-A-9-18885, JP-A-9-188686, JP-A-9-188710. Organoboron ammonium compounds described in JP-A-6-175561, JP-A-6-175564, JP-A-6-157623, and the like. Organoboron iodonium compounds described in JP-A-6-175553, JP-A-6-175554, etc., Organoboron phosphonium compounds described in JP-A-9-188710, JP-A-6-348011, JP-A-7- 128785, JP-A-7-140589, JP-A-7-292 14 JP, organic boron transition metal coordination complex compound described in JP-A-7-306527 Patent Publication, and the like. Examples of the counter anion described in JP-A-62-143044 and JP-A-5-194619 include cationic dyes containing an organic boron anion.

  When the photocurable photosensitive layer of the present invention is adapted for exposure to blue-violet light in the wavelength range of 400 to 430 nm, (d) hexaarylbiimidazole, (h) metallocene compound, (i) trihaloalkyl Substituted compounds and (j) organic boron salt compounds are particularly preferred.

  In addition, when the photocurable photosensitive layer of the present invention is adapted to exposure with near infrared to infrared light in a wavelength range of 750 to 1100 nm, (i) a trihaloalkyl-substituted compound and (j) an organic boron salt compound are particularly preferred. preferable.

  The above photopolymerization initiators may be used alone or in any combination of two or more. In particular, it is preferable to use a combination of (i) a trihaloalkyl-substituted compound and (j) an organic boron salt compound because the sensitivity is greatly improved. The content of the photopolymerization initiator in the photocurable photosensitive layer is preferably in the range of 1 to 100% by mass, more preferably in the range of 1 to 40% by mass with respect to the polymer.

  As the photopolymerization initiator related to the present invention, an organic boron salt is particularly preferably used. More preferably, an organic boron salt and a trihaloalkyl-substituted compound (for example, an s-triazine compound, an oxadiazole derivative or a trihaloalkylsulfonyl compound as a trihaloalkyl-substituted nitrogen-containing heterocyclic compound) are used in combination.

  The organic boron anion constituting the organic boron salt is represented by the following general formula IV.

In the formula, each of R ₅ , R ₆ , R ₇ and R ₈ may be the same or different, and represents an alkyl group, aryl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group or heterocyclic group. To express. Of these, it is particularly preferred that one of R ₅ , R ₆ , R ₇ and R ₈ is an alkyl group and the other substituent is an aryl group.

  In the above-mentioned organoboron anion, a cation that forms a salt is simultaneously present. Examples of the cation in this case include alkali metal ions, onium ions, and cationic sensitizing dyes. Onium salts include ammonium, sulfonium, iodonium and phosphonium compounds. When a salt of an alkali metal ion or onium compound and an organic boron anion is used, photosensitivity in the wavelength range of light absorbed by the dye is imparted by adding a sensitizing dye separately. Further, when an organic boron anion is contained as a counter anion of the cationic sensitizing dye, photosensitivity is imparted according to the absorption wavelength of the sensitizing dye. However, in the latter case, it is preferable to further contain an organic boron anion as a counter anion of the alkali metal or onium salt.

  The organic boron salt used in the present invention is a salt containing the organic boron anion represented by the general formula IV shown above, and alkali metal ions and onium compounds are preferably used as cations forming the salt. Particularly preferable examples of the onium salt with an organic boron anion include ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and phosphonium salts such as triarylalkylphosphonium salts. Examples of particularly preferred organic boron salts are shown below.

  In the present invention, a trihaloalkyl-substituted compound can be used as a photopolymerization initiator that can be used with an organic boron salt to achieve higher sensitivity and higher contrast. Specifically, the trihaloalkyl-substituted compound is a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. As a preferable example, the trihaloalkyl group is a nitrogen-containing complex. Examples of the compound bonded to the ring group include s-triazine derivatives and oxadiazole derivatives, or trihaloalkylsulfonyl compounds in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocycle via a sulfonyl group. .

  Particularly preferred examples of trihaloalkyl-substituted nitrogen-containing heterocyclic compounds and trihaloalkylsulfonyl compounds are shown below.

  In the photopolymerizable photosensitive layer according to the present invention, the light wavelength region has light absorption in the wavelength region of 400 to 430 nm or 750 to 1100 nm, and the above-mentioned photopolymerization initiator is sensitized at these wavelengths. It is preferable that the compound to be contained is also contained. 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, 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. Examples of cyanine dyes that can be preferably used are shown below.

  Examples of preferred coumarin compounds that can be used to increase the sensitivity in the wavelength range of 400 to 430 nm are shown below.

  Examples of preferred (thio) pyrylium compounds that can be used to increase the sensitivity in the wavelength region of 400 to 430 nm are shown below.

  As sensitizing dyes in the wavelength range of 750 to 1100 nm, cyanine dyes, porphyrins, spiro compounds, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, polyenes, azo compounds, diphenylmethane, triphenylmethane, polymethine acridine, Examples include coumarin, ketocoumarin, quinacridone, indigo, styryl, squarylium compounds, (thio) pyrylium compounds, European Patent No. 568,993, US Patent No. 4,508,811, US Patent The compounds described in US Pat. No. 5,227,227 can also be used.

  Examples of preferred sensitizing dyes corresponding to near infrared light in the wavelength range of 750 to 1100 nm are shown below.

  With respect to the present invention, various polyfunctional monomers can also be contained in the photopolymerizable photosensitive layer. Examples of such polyfunctional monomers include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trisacryloyloxyethyl isocyanurate, tripropylene glycol. Polyfunctional (acrylic) monomers such as diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or various polymers having acryloyl group or methacryloyl group introduced as polyester (meth) acrylate, urethane (meta ) Acrylates, epoxy (meth) acrylates and the like are used in the same manner.

  In addition, as an element constituting the photopolymerizable photosensitive layer, various kinds of dyes and pigments are added for the purpose of enhancing image visibility, and inorganic fine particles or organic fine particles are used for the purpose of preventing blocking of the photosensitive composition. It is also preferably carried out.

  In order to prevent the curing reaction in the dark due to thermal polymerization, a polymerization inhibitor is preferably added to the photocurable photosensitive layer for long-term storage. As the polymerization inhibitor preferably used for such purposes, various known phenol compounds can be used.

  Regarding the dry solid content coating amount of the photopolymerizable photosensitive layer itself when used as a photosensitive lithographic printing plate material, the dry solid content coating amount in the range of 0.3 g to 10 g per square meter on the dry weight on the hydrophilic layer. It is preferable that the thickness is in the range of 0.5 g to 3 g in order to achieve good resolution and greatly improve printing durability. The photopolymerizable photosensitive layer is prepared by preparing a solution in which the above-described various elements are mixed, and is applied and dried on the hydrophilic layer using various known coating methods.

  In the photosensitive lithographic printing plate material of the present invention, a protective layer is preferably further provided on the photopolymerizable 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, light transmission used for exposure is not substantially inhibited, and adhesion to the photosensitive layer. It is desirable that it is excellent in that it can be easily removed in the development process after exposure. In the water-developable photosensitive lithographic printing plate material of the present invention, it is possible to simultaneously remove such an unexposed portion of the protective layer and the photocurable photosensitive layer in the course of water development. It is a feature that it is not necessary to provide a removal process. Further, when the polymer contained in the photo-curable photosensitive layer as described above is water-soluble, it absorbs moisture in the atmosphere and causes blocking, or causes a problem such as sensitivity change during storage. However, it is possible to solve such problems of blocking and sensitivity change by providing a protective layer on the photocurable photosensitive layer. In addition, particularly when recording is performed using a blue-violet semiconductor laser having a wavelength range of 400 to 430 nm, since the laser output is generally lower than that of a near-infrared semiconductor laser, the photosensitive layer is particularly sensitive. Is required. In such a case, since the sensitivity is further increased by providing a protective layer, it can be particularly preferably applied.

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

  In order to use a material having a hydrophilic layer and a photopolymerizable photosensitive layer formed on a plastic support as described above as a printing plate, the exposed portion is subjected to contact exposure or laser scanning exposure. Since the solubility in water decreases due to crosslinking, pattern formation is performed by eluting unexposed portions with water.

  In the present invention, it is most preferable that the water used for water development has a pH in the range of 4 to 9 and does not substantially contain chemicals. However, in accordance with the water developability of the photosensitive lithographic printing plate material, pure water may contain various inorganic and organic ionic compounds at a concentration of 1% or less, including sodium, potassium, calcium, magnesium ions, etc. May be water. Alternatively, various surfactants known in water may be contained at a concentration of 1% or less. Further, water may contain various alcohols such as methanol, ethanol, propanol, isopropanol, ethylene glycol, propylene glycol, methoxyethanol, and polyethylene glycol at a concentration of 1% or less. Alternatively, when developing with water, development by adding various commercially available gum solutions at a concentration of 1% or less can also be preferably used for the purpose of protecting the plate surface from fingerprint stains and the like. Even if these chemicals such as various inorganic and organic ionic compounds, various surfactants, solvents or gum solutions are contained in pure water alone or mixed, they are used in water development related to the present invention. For water, chemicals are preferably used at a concentration of 3% or less by mass%.

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

(Synthesis Example 1) Synthesis Example of Water-Soluble Polymer Having Polymerizable Double Bond Group in Side Chain 50 parts of allyl methacrylate and 40 parts of acrylamide-2-methylpropanesulfonic acid are added to 300 parts of ethanol, and 50 parts of distilled water And 27 parts of dimethylaminoethanol was added and dissolved. It heated at 70 degreeC and superposed | polymerized by adding 2 parts of azobisisobutyronitrile (AIBN) as a polymerization initiator in nitrogen atmosphere. The mixture was heated and stirred at 70 ° C. for 6 hours to obtain a polymer solution having the following structure.

(Synthesis example 2) Synthesis example of water-soluble polymer (SP-8) having a polymerizable double bond group in the side chain According to the synthesis example described in JP-A-2001-290271, p-chloromethylstyrene (AGC) A compound (hereinafter referred to as M-1) having the following structure was obtained from CMS-14) manufactured by Seimi Chemical Co., Ltd. and bismuthiol.

  In a 1-liter flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, add 350 parts of ethanol and 50 parts of distilled water, add 80 parts of M-1 to the flask, and further add acrylamide-2-methyl. 120 parts of propanesulfonic acid and 80 parts of dimethylaminoethanol were added and the whole was heated to 70 ° C. and dissolved in a nitrogen atmosphere. Two parts of AIBN was added as a polymerization initiator to initiate polymerization, and the mixture was stirred with heating at 70 ° C. for 12 hours. The whole was cooled to 50 ° C., 1 part of cuperone (N-nitrosophenylhydroxylamine ammonium salt) was added as a polymerization inhibitor, and 46 parts of p-chloromethylstyrene was further added, followed by stirring at this temperature for 5 hours. . Then, it cooled to room temperature, the depositing deposit was isolate | separated by decantation, and it dried, after washing | cleaning thoroughly with methanol. A white polymer was obtained with a yield of 80%. Analysis of the product by GPC has a weight average molecular weight of about 120,000, and as a result of structural analysis by proton NMR, the presence of a polymerizable double bond was confirmed and found to be consistent with the structure shown by SP-8 as the structure. .

(Examples 1 to 5 and Comparative Examples 1 to 3 of photosensitive lithographic printing plate materials)
Using a polyester film having a thickness of 175 μm having a subbing layer in which vinylidene chloride and gelatin are laminated in this order, a hydrophilic layer is formed on the polyester film as shown in Table 1 below. Application | coating was performed using a wire bar so that it might become 3g per square meter by dry weight using prescription (parts). Drying was performed by heating for 20 minutes with a dryer at 80 ° C. The sample was further heated in a dryer at 40 ° C. for 3 days, and then fed to the subsequent application of the photopolymerizable photosensitive layer. In Table 1, sodium silicate No. 1 (SiO ₂ = 30%, Na ₂ O = 15%) manufactured by Fuji Chemical Co., Ltd. was used as the water glass, and Tospearl 145 (Momentive Performance Materials) was used as the silicone-based organic fine particles. -Japan GK company: Spherical fine particle: Average particle diameter 4.5micrometer) was used. As an anionic surfactant, Perex NBL (sodium alkyl naphthalene sulfonate manufactured by Kao Corporation) was used. As the colloidal silica, Snowtex PS-S (20% concentration) manufactured by Nissan Chemical Industries, Ltd. was used. A 10% aqueous solution of polyacrylamide-acrylic acid (80/20) copolymer was used as the water-soluble polymer. As a crosslinking agent, epoxy crosslinking agent Denacol EX-512 manufactured by Nagase Sangyo Co., Ltd. was used. As a method for preparing the hydrophilic layer coating solution, first, water glass was diluted with distilled water, and phosphoric acid was gradually added thereto to prepare a water glass aqueous solution having a pH of 4.0, which is shown in Table 1. Other additives were added in order to prepare a coating solution.

  The polyester film having the hydrophilic layer prepared above was used, and the photopolymerizable photosensitive layer was coated on the hydrophilic layer using the photopolymerizable photosensitive layer formulation shown below. The numerical value shown in the following prescription represents the mass applied per square meter. The water-soluble polymers shown in Table 2 were used as the water-soluble polymers used in the respective examples and comparative examples. The photopolymerizable photosensitive layer was coated using a wire bar so that the coating amount was as follows. Drying was performed by heating for 10 minutes in a dryer at 80 ° C.

(Photopolymerizable photosensitive layer formulation)
1g of water-soluble polymer
Photopolymerization initiator (BC-6) 0.1g
Photopolymerization initiator (T-6) 0.05g
Sensitizing dye (S-36) 0.03g
Multifunctional monomer (pentaerythritol tetraacrylate) 0.5g
Phthalocyanine blue (coloring pigment) 0.02g
4g of distilled water
Dioxane 5g
1g of ethanol

(exposure)
The photosensitive lithographic printing plate material produced as described above was subjected to an exposure test as follows. For the exposure, PT-R4000 (Dainippon Screen Mfg. Co., Ltd.) equipped with a laser having a light wavelength of 830 nm was used. In order to perform drawing using this apparatus, the photosensitive lithographic printing plate material was laminated on a 0.24 mm aluminum plate using a cellophane tape so that the photosensitive layer was on the surface. The exposure energy was set to 120 mJ / cm ² on the film surface, and drawing was performed at a drum rotation speed of 1000 rpm. As a test image, a halftone dot pattern showing a halftone dot area ratio from 1% to 97% corresponding to 2400 dpi and 175 lines and a thin line of 10 to 100 μm were output.

(Water development processing)
Using each photosensitive lithographic printing plate on which drawing was performed as described above, an automatic developing device PD-912-M (manufactured by Dainippon Screen Mfg. Co., Ltd.) for an aluminum printing plate (PS plate) was used as an automatic development processing device. Water development processing was performed. Pure water adjusted to 30 ° C. was introduced into the developing tank, and the developing time was set to 12 seconds. In order to carry out processing using this apparatus, the photosensitive lithographic printing plate material was laminated on a 0.24 mm aluminum plate with a cellophane tape so that the photosensitive layer was on the surface, and passed through an automatic developing apparatus. The photosensitive lithographic printing plate material was adjusted so that the photocurable photosensitive layer in most non-image areas was removed by rubbing the surface of the photosensitive lithographic printing plate material weakly with a Molton roll. After rubbing development with a Molton roll, excess water on the surface of the photosensitive lithographic printing plate material was squeezed out by two squeezing rolls at the outlet of the developing tank. Subsequently, the surface was shower-washed in a water rinsing tank, and finally dried with warm air.

(Scratch resistance evaluation)
Using each of the photosensitive lithographic printing plate materials that had been subjected to the water development treatment as described above, scratch resistance was evaluated as follows. That is, a HEIDON-18 type continuous load type scratch tester is used, a needle having a needle tip of 1000 μm is mounted, and a contact angle between the needle tip and the hydrophilic layer which is a non-image portion of the photosensitive lithographic printing plate material is set to 60. The temperature was set at 0 ° and scratched every 10 g from 10 g to 100 g. Thereafter, in printing durability evaluation described later, when 100 sheets were printed, the scratch resistance was evaluated with the minimum load at which the scratch marks were recognized on the printed matter. The results are shown in Table 3 as scratch resistance evaluation.

(Fingerprint trace evaluation)
Using each of the photosensitive lithographic printing plate materials that had been subjected to the water development treatment as described above, anti-fingerprint marks were evaluated as follows. That is, the palm was pressed for 1 minute on the hydrophilic layer, which is a non-image area of the photosensitive lithographic printing plate material, and then left in a drier kept at 40 ° C. for 1 week. Thereafter, in the printing durability evaluation described later, when 100 sheets were printed, the case where the fingerprint trace was clearly recognized on the printed material was marked as x, and the case where the fingerprint trace was slightly recognized was marked as Δ, and the fingerprint trace was The results are shown in Table 3 with ◯ when no recognition was observed.

(Cleaner liquid suitability evaluation)
Using each of the photosensitive lithographic printing plate materials subjected to the above water development treatment, the suitability of the cleaner liquid was evaluated as follows. That is, an appropriate amount of ink is deposited on the hydrophilic layer using FINE INK New Champion Purple S (manufactured by DIC Corporation) as an ink on the hydrophilic layer which is a non-image portion of the photosensitive lithographic printing plate material. After that, the ink adhering surface was wiped off with a soft cloth using a three power manufactured by Nikken Chemical Laboratory as a cleaner liquid. After that, in the printing durability evaluation described later, when 100 sheets were printed, the case where the area wiped off with the cleaner liquid was clearly recognized as background dirt on the printed matter was marked as x, and the case where it was slightly recognized as a trace. The results are shown in Table 3 with △ as the case where no wiping trace was observed.

(Evaluation of printing durability)
Evaluation of printing durability was Heidelberg TOK (trademark of offset printer manufactured by Haidelberg) for printing press, FINE INK New Champion Purple S (made by DIC Corporation) for ink, and Eu-3 (Fuji Photo Film Co., Ltd.) for dampening water. Using a 0.5% aqueous solution of PS plate fountain solution), printing is continuously performed up to 30,000 sheets, and there is a problem in the reproducibility of 10-100 μm fine lines and halftone pattern on printed matter The evaluation was performed with the number of printed sheets starting to be recognized. The results are also shown in Table 3.

(Examples 6-10 and Comparative Examples 4-6 of photosensitive lithographic printing plate materials)

  In the previous Examples 1 to 5 and Comparative Examples 1 to 3, the sensitizing dye in the photopolymerizable photosensitive layer formulation was used in place of S-11, and polyvinyl alcohol was used as a protective layer on the photopolymerizable photosensitive layer. A photosensitive lithographic printing plate material was used in the same manner except that coating was performed using a wire bar so that the dry coating weight was 2.0 g per square meter using (Kuraray Co., Ltd. PVA-105). Examples 6 to 10 and Comparative Examples 4 to 6 were prepared.

(Exposure test)
The photosensitive lithographic printing plate material produced as described above was subjected to an exposure test as follows. For exposure, a CTP image setter VIPLAS (manufactured by Mitsubishi Paper Industries Co., Ltd.) equipped with a semiconductor laser having a light wavelength of 405 nm is used, and the exposure energy on the printing plate is set to 80 μJ / cm ² using this apparatus. Drawing was performed by a scanning exposure method. As a test image, a halftone dot pattern showing a halftone dot area ratio from 1% to 97% corresponding to 2400 dpi and 175 lines and a thin line of 10 to 100 μm were output.

  Using each of the photosensitive lithographic printing plates exposed as described above, water development treatment was performed in exactly the same manner as in Examples 1 to 3 above, and further using these, scratch resistance in the same manner as in the previous example. Evaluation, fingerprint resistance evaluation, cleaner liquid suitability evaluation and printing durability evaluation were performed. The results are summarized in Table 4, respectively.

  From the above results, photosensitive lithographic printing that can be developed with water according to the present invention, has excellent printing durability, prevents printing stains due to scratches and fingerprints on the surface of the hydrophilic layer, and has improved cleaner liquid suitability. It can be seen that a plate material is obtained.

  In CTP printing plates using a scanning exposure device that uses a laser that emits light near 830 nm or a laser that emits light in the wavelength range near 405 nm, water development is possible with less flaws and fingerprints on non-image areas. A plastic film based printing plate is provided. Furthermore, a production system suitable for forming a printed wiring board production resist, a color filter, a phosphor pattern, and the like is provided.

Claims (4)

  In a photosensitive lithographic printing plate material in which a hydrophilic layer and a photopolymerizable photosensitive layer containing a water-soluble polymer are provided in this order on a plastic film support, the hydrophilic layer contains silicone-based organic fine particles and water glass. Photosensitive lithographic printing plate material.   The photosensitive lithographic printing according to claim 1, wherein the water-soluble polymer is a water-soluble polymer having both a sulfonate group and a phenyl group to which a vinyl group is bonded via a linking group containing a hetero ring in a side chain. Plate material.   The photosensitive lithographic printing plate material according to claim 1, wherein the hydrophilic layer further contains colloidal silica and a water-soluble polymer.   The photopolymerizable photosensitive layer contains a photopolymerization initiator and a compound that sensitizes the photopolymerization initiator to light having a wavelength range of 400 to 430 nm or 750 nm to 1100 nm. The photosensitive lithographic printing plate material according to claim 1.