JP4705135B2 - Photosensitive composition - Google Patents

Description

  The present invention relates to a photosensitive composition that can be used for preparing a lithographic printing plate, a resist for preparing a printed wiring board, a color filter, a phosphor pattern, and the like, and particularly relates to a photosensitive composition suitable for a lithographic printing plate. Furthermore, the present invention relates to a photosensitive composition capable of forming an image by scanning exposure such as a laser and capable of being developed with water. Further, the present invention relates to a lithographic printing plate and a printing method that can be directly mounted on a printing machine after exposure and printed.

  As a photosensitive composition that can be developed with water, for example, a photosensitive composition in which a dichromate is added to a water-soluble polymer such as gelatin or polyvinyl alcohol has been used as a color filter material. Therefore, various systems have been studied as photosensitive compositions that can be substituted for these.

  For example, an example of a water-developable photosensitive material using a polymer obtained by condensation addition of a quaternary ammonium salt compound such as a styrylpyridinium salt compound or a styrylquinolinium salt compound to polyvinyl alcohol is disclosed in Japanese Patent Publication No. 56-5761. Although described in JP-A-56-5762 and JP-A-56-11906, etc., they did not exhibit sufficient characteristics in terms of resolution and sensitivity.

  Alternatively, a light-sensitive material in which a water-soluble azide compound and a water-soluble polymer that can be cross-linked thereby are combined is well known. As the water-soluble polymer in this case, JP-A-48-97602 discloses a polyvinyl alcohol-maleic acid copolymer, and JP-A-48-97603 discloses a polyvinyl alcohol-acrylamide copolymer. The sensitivity was low. Similarly, as can be seen in JP-A-48-90185, etc., when polyvinylpyrrolidone is used as the water-soluble polymer, a certain degree of high sensitivity is obtained, but it is still not sufficient. In addition, even in a system using a poly (meth) acrylamide-diacetone acrylamide copolymer as seen in Japanese Patent Publication No. 52-20225 and Japanese Patent Application Laid-Open No. 2000-248027, etc., in terms of resolution and sensitivity. It was not satisfactory.

  Examples in which a photosensitive azide group is introduced into the water-soluble polymer itself with the aim of increasing the sensitivity are described in, for example, JP-A-9-185163 and JP-A-11-84655. It was difficult to achieve both storage stability and there was a problem in practical use.

  Similarly, an example of a water-developable photosensitive composition in which a polymerizable unsaturated bond group is introduced into a side chain of polyvinyl alcohol and further a photopolymerization initiator is used with the aim of achieving high sensitivity is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-2000. 181062 and the like. In this case, since the group having a polymerizable unsaturated bond group introduced into the side chain is introduced as a side chain of polyvinyl alcohol by the acetalization reaction, the polymer obtained can be obtained by increasing the introduction rate in order to increase sensitivity. As a result, there was a problem that water developability was lowered.

  Furthermore, when the water-developable photosensitive composition as described above is to be used for lithographic printing plate applications, the image area after development is extremely poor in lipophilicity, and the image is swelled with water. The strength was weak and it could not withstand normal lithographic printing.

  Japanese Patent Publication No. 55-13020 discloses a photosensitive composition using a cationic water-soluble polymer having an unsaturated bond group (Patent Document 1). The photosensitive composition of the publication utilizes photodimerization between unsaturated bonding groups, and this is the same reaction mechanism as the well-known photodimerization of cinnamic acid and the photodimerization of styrylpyridinium salt. . This photodimerization reaction mechanism does not involve a photopolymerization initiator or a photoacid generator. Therefore, unlike the crosslinking reaction by a photopolymerization initiator and a photoacid generator essential in the present invention, the above publication does not describe the constitution of the present invention at all. In addition, the photosensitive composition of the publication is substantially sensitive only to ultraviolet rays, has a low sensitivity because there is no amplification process, requires high energy for exposure, and further changes from visible light to near infrared light. Had no sensitivity and could not be applied to an output machine using laser light described later.

  JP-A-9-101620 discloses a photosensitive composition using a polymer having a cationic group and a (meth) acryloyl group in the side chain (Patent Document 2). This is a printing plate material compatible with flexographic printing, but has poor water developability and has a problem of requiring a long time for development. Furthermore, when the photosensitive composition is used for ordinary lithographic printing plate applications, there has been a problem that the ink is inferior in terms of ink setting and printing durability.

  In the field of lithographic printing plates, in recent years, with the advance of image forming technology, photosensitive compositions exhibiting high sensitivity to visible light have been demanded. For example, research on photosensitive compositions and photosensitive lithographic printing plates corresponding to output machines using argon lasers, helium-neon lasers, red LEDs, and the like has been actively conducted.

  Furthermore, with the remarkable progress of semiconductor lasers, a near-infrared laser light source of 700 to 1300 nm can be easily used, and a photosensitive composition and a photosensitive lithographic printing plate corresponding to the laser beam have attracted attention. Yes. In addition, drawing apparatuses (plate setters) using near-ultraviolet semiconductor lasers emitting near 400 nm are also appearing on the market, and these are highly sensitive photosensitive compositions and photosensitivities capable of image formation (plate making). A lithographic printing material is desired.

  As a photopolymerizable composition having photosensitivity to visible light to near infrared light, JP-A-9-134007 discloses a radically polymerizable compound having an ethylenically unsaturated bond and an absorption peak at 400 to 500 nm. A lithographic printing plate material containing a photosensitizing dye and a polymerization initiator is disclosed, and JP-A-62-143044, JP-A-62-1050242, JP-A-5-5988, JP-A-5-194619, JP-A-5-197069 and JP-A-2000-98603 disclose a combination of an organic boron anion and a dye, and JP-A-4-31863 and JP-A-6-43633 disclose a dye and S-triazine. JP-A-7-20629 and JP-A-7-271029 disclose a resol resin, a novolac resin, an infrared absorber, and a photoacid generator. The combination of disclosure, JP-11-212252, a combination of a specific polymer and a photoacid generator and a near infrared sensitizing dyes is disclosed in Dotaira 11-231535 Patent Publication. JP-B-6-105353, JP-A-2001-290271, and the like disclose a photosensitive composition using a polymer having a phenyl group substituted with a vinyl group (Patent Documents 3 and 4). .

  However, in any of the above examples, the binder polymer used in the photosensitive layer is not water-soluble, and when developing, a strong alkaline compound such as sodium hydroxide, potassium hydroxide, potassium silicate or the like is used as a developer. It was necessary to use a dissolved alkaline aqueous solution, and it was not possible to develop with water. Further, in the development, it was necessary to perform development using a dedicated automatic developing device.

  On the other hand, a lithographic printing plate that can be developed with water or that does not require the development process itself is desired. For example, development using ablation removal of the binder polymer by irradiation with a high-power near-infrared semiconductor laser is not required. An unprocessed printing version has been proposed. For example, JP-A-8-48018 discloses a method for producing a lithographic printing plate by removing an ink-receptive polymer by ablation and exposing a hydrophilic support surface with a cleaning agent. There is a problem in that an ablation residue called debris is generated, which may cause contamination of the optical system or soiling of the printing plate.

As another trial, the above high-power near-infrared semiconductor laser is used, a layer containing thermoplastic polymer fine particles is provided as a heat-sensitive layer, and polymer fine particles are fused using high heat generated in the laser irradiation part. Examples of heat-sensitive lithographic printing plates that are water insoluble and can be developed with water are disclosed in JP-A-9-171250, JP-A-10-186646, JP-A-11-265062, and US Pat. No. 6,001,536. It is described in gazettes. These are preferable systems that can be mounted on a printing machine as they are without being subjected to development processing and can be printed. However, there are problems such as low sensitivity to laser light and easy occurrence of background stains.
Japanese Examined Patent Publication No. 55-13020 (pages 1 to 4) JP-A-9-101620 (pages 1 to 4) Japanese Examined Patent Publication No. 6-105353 (pages 1 to 5) JP 2001-290271 A (pages 1 to 7)

  Accordingly, an object of the present invention is to provide a photosensitive composition that is highly sensitive and capable of water development. In particular, an object of the present invention is to provide a photosensitive composition that is sufficiently sensitive even in scanning exposure with a laser of visible light to infrared light and that can be developed with water, and a lithographic printing plate using the same. A further object of the present invention is to provide a lithographic printing plate and a printing method which do not require a developing device and can be directly mounted on a printing press for printing without performing a developing process.

  According to the present invention, it is possible to provide a photosensitive composition that can be developed with high sensitivity and water. In particular, it is possible to provide a photosensitive composition that is sufficiently sensitive in scanning exposure with visible to infrared lasers and that can be developed with water, and a lithographic printing plate using the same. Furthermore, it is possible to provide a lithographic printing plate and a printing method that do not require a developing device and that can be mounted on a printing machine and printed without being subjected to development processing.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be basically solved by using the photosensitive composition described below.
(1) a polymerizable unsaturated bond group possess two or more in a molecule, a cationic monomer which have a quaternary ammonium group as a cationic group, containing a polymer, and a photopolymerization initiator or photoacid generator The photosensitive composition characterized by the above-mentioned.

  The present invention is described in detail below. The mode (1) of the photosensitive composition of the present invention is a cationic water-soluble polymer (hereinafter referred to as water-soluble polymer A) having a phenyl group substituted with a vinyl group in the side chain as the water-soluble polymer. A photosensitive composition containing a water-soluble polymer having a phenyl group substituted with a vinyl group in the side chain and a sulfonate group (hereinafter referred to as water-soluble polymer B), and a photopolymerization initiator or photoacid generator. is there.

  The water-soluble polymer A used in the present invention represents a polymer in which a phenyl group substituted with a vinyl group is introduced into a side chain in a water-soluble polymer having a cationic group. Hereinafter, the water-soluble polymer A will be described in detail.

  The cationic group in the water-soluble polymer A is a group selected from organic onium groups such as an ammonium group, a sulfonium group, a phosphonium group, an iodonium group, and an oxonium group, and among these, a quaternary ammonium group is most preferable. .

  The above-mentioned polymer having an organic onium group introduced therein is described in JP-B-55-13020, JP-A-55-22766, JP-A-11-153589, JP-A-2000-103179, US Pat. No. 4,693,958, It can be synthesized using a conventionally known chemical reaction described in US Pat. No. 5,512,418. That is, a monomer containing a desired organic onium group is subjected to a polymerization reaction, or a trivalent N atom, a divalent S atom or a trivalent P atom introduced on a polymer chain constituting the polymer is usually used. The method of introduce | transducing an organic onium group is mentioned by the alkylation reaction. Furthermore, the polymer main chain or side chain is obtained by a nucleophilic substitution reaction between a nucleophilic reagent such as amines, sulfides, and phosphines and a leaving group on the polymer chain (for example, sulfonate esters or halides). In addition, a method of introducing an organic onium group into the base is also included.

  The phenyl group substituted with a vinyl group in the water-soluble polymer A is a group that can contribute to a photopolymerization reaction or a photocrosslinking reaction by the action of a photopolymerization initiator or a photoacid generator. The phenyl group substituted with a vinyl group is preferably introduced into the polymer via an appropriate linking group. In this case, the linking group is not particularly limited, and includes an arbitrary group, an atom, or a complex group thereof. Furthermore, the vinyl group and the phenyl group may have a substituent. More specifically, the polymer introduced with a phenyl group substituted with a vinyl group has a group represented by the following general formula 1 in the side chain.

In the formula, R ¹ , R ² and R ³ may be the same or different, and each is a hydrogen atom, halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group. A group selected from a group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, and an arylsulfonyl group And the alkyl group and aryl group constituting these groups are halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkenyl group, alkynyl group, hydroxy group , Alkoxy group, aryloxy group, alkylthio group, arylthio A group, an alkylamino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group and the like. Among these groups, those in which R ¹ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (for example, a methyl group, an ethyl group, etc.) and R ² and R ³ are hydrogen atoms are particularly preferable.

In the formula, R ⁴ is a halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkyl group. It represents a substitutable group such as an amino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group. The alkyl group and aryl group constituting these groups are halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkenyl group, alkynyl group, hydroxy group. , An alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group and the like.

In the formula, m ₁ represents an integer of 0 to 4, p ₁ represents an integer of 0 or 1, and q ₁ represents an integer of ₁ to 4.

Wherein, L ₁ represents a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom, a polyvalent connecting group composed of atoms or atomic groups selected from a sulfur atom. Specific examples include groups composed of structural units exemplified below and heterocyclic groups shown below. These groups may be used alone or in any combination of two or more. Furthermore, these groups may have a substituent.

Examples of the heterocyclic ring constituting L ₁ include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thia Triazole ring, 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 And a nitrogen-containing heterocycle such as a ring and a quinoxaline ring, a furan ring, a thiophene ring, and the like. These heterocycles may have a substituent.

  When the polyvalent linking group described above has a substituent, examples of the substituent include a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkenyl group, and an alkynyl group. Group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group and the like.

A case where an organic onium group such as a quaternary ammonium group forming a cationic group is included in any atomic group constituting the linking group (L ₁ ) is particularly preferably used. When such an organic onium group is not included in the linking group, it is necessary that the repeating unit constituting the main chain further includes a repeating unit having an organic onium group.

  The method for introducing a phenyl group substituted with a vinyl group into the polymer is not particularly limited. For example, JP-B-49-34041, JP-A-6-105353, JP-A-2000-181062, and JP-A-2000-187322. Any method as shown in a publication or the like may be used. In these cases, when a polymer as a precursor is synthesized in advance, a repeating unit having an organic onium group is introduced in the form of a copolymer, or a polymerizable unsaturated bonding group is introduced into the precursor polymer. Later, it is necessary to form an organic onium group by the method described above.

  Specific examples of monomers that can constitute the water-soluble polymer A include allylamine, diallylamine, 2-dimethylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl acrylate, 2-diethylaminoethyl methacrylate, 3- Dimethylaminopropylacrylamide, 3-dimethylaminopropylmethacrylamide, 4-aminostyrene, 4-aminomethylstyrene, N, N-dimethyl-N- (4-vinylbenzyl) amine, N, N-diethyl-N- (4 -Amino group-containing monomers such as vinylbenzyl) amine and quaternary ammonium salts thereof, nitrogen-containing heterocycle-containing monomers such as 4-vinylpyridine, 2-vinylpyridine, N-vinylimidazole, N-vinylcarbazole and the like. Ammonium salt, quaternary phosphonium salt monomer such as (4-vinylbenzyl) trimethylphosphonium bromide, tertiary sulfonium salt monomer such as dimethyl-2-methacryloyloxyethylsulfonium methosulfate, 2-chloromethylstyrene, 4-chloromethylstyrene , Halogenated alkyl group-containing monomers such as 4-bromomethylstyrene, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, and the like, but are not limited thereto.

  In addition, the water-soluble polymer A may constitute a copolymer with any other monomer, and the monomer constituting the copolymer may be water-soluble or water-insoluble. . Specific examples of water-soluble monomers include 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 esters, 4-carboxystyrene, carboxyl group-containing monomers such as acrylamide-N-glycolic acid and their salts, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylate, 3 -Sulfo group-containing monomers such as sulfopropyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and salts thereof, phosphate group-containing monomers such as vinylphosphonic acid and salts thereof, allylamine, diallylamine, 2- Methylaminoethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl acrylate, 2-diethylaminoethyl methacrylate, 3-dimethylaminopropyl acrylamide, 3-dimethylaminopropyl methacrylamide, 4-aminostyrene, 4-aminomethylstyrene, Amino group-containing monomers such as N, N-dimethyl-N- (4-vinylbenzyl) amine, N, N-diethyl-N- (4-vinylbenzyl) amine, and quaternary ammonium salts thereof, 4-vinylpyridine, Nitrogen-containing heterocycle-containing monomers such as 2-vinylpyridine, N-vinylimidazole and N-vinylcarbazole, and quaternary ammonium salts thereof, acrylamide, methacrylamide, N, N-dimethylacrylamide, N, N-dimethyl (Meth) acrylamides such as methacrylamide, N, N-diethylacrylamide, N-isopropylmethacrylamide, diacetoneacrylamide, N-methylolacrylamide, 4-hydroxyphenylacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate , Alkylenes such as 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, hydroxyalkyl (meth) acrylates such as glycerol monomethacrylate, methacrylic acid methoxydiethylene glycol monoester, methacrylic acid methoxypolyethylene glycol monoester, methacrylic acid polypropylene glycol monoester Oxy group-containing (meth) acrylates, N-vinylpyrrolidone, N-vinyl Examples include, but are not limited to, lucaprolactam. These water-soluble monomers may be used alone or in combination of any two or more.

  In order to optimize water developability and improve the strength of the image area, it is also preferable to form a copolymer with any water-insoluble monomer. Examples of these include styrene, 4- Styrene derivatives such as methylstyrene, 4-hydroxystyrene, 4-acetoxystyrene, 4-chloromethylstyrene, 4-methoxystyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, Alkyl (meth) acrylates such as 2-ethylhexyl methacrylate, cyclohexyl acrylate and dodecyl methacrylate, aryl (meth) acrylates such as phenyl methacrylate and benzyl methacrylate, or arylalkyl (meth) acrylate Tones, acrylonitrile, methacrylonitrile, phenylmaleimide, hydroxyphenylmaleimide, vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl benzoate, etc., methyl vinyl ether, butyl vinyl ether, etc. Examples include vinyl ethers, other monomers such as acryloylmorpholine, tetrahydrofurfuryl methacrylate, vinyl chloride, vinylidene chloride, allyl alcohol, vinyltrimethoxysilane, and glycidyl methacrylate. A copolymer composed of any combination of these can be used as the water-soluble polymer A.

  The water-soluble polymer A of the present invention is particularly preferably a case where a phenyl group substituted with a vinyl group is bonded to the main chain via a cationic group. Arbitrary atomic groups constituting a linking group for bonding a phenyl group substituted with a vinyl group to the main chain include an organic onium group such as a quaternary ammonium group forming a cationic group. It is most preferable. In this case, the number of phenyl groups substituted by vinyl groups contained in the polymer is directly proportional to the number of organic onium groups, so that the phenyl groups substituted by vinyl groups in the polymer are improved in order to improve sensitivity. Even if the ratio is increased, the solubility in water does not decrease, so that both sensitivity and water developability can be satisfied at the same time. The unit structure of the polymer in the case where the phenyl group substituted with a vinyl group as described above is bonded to the main chain via a cationic group can be specifically represented by the following general formula 3.

In the formula, A ₁ ⁺ represents an organic onium group selected from organic onium groups such as an ammonium group, a sulfonium group, a phosphonium group, an iodonium group, and an oxonium group, and n ₁ and n ₂ each represents 0 or 1. When A ₁ ⁺ is an iodonium group, n ₁ = n ₂ = 0, and when A ₁ ⁺ is a sulfonium group or an oxonium group, n ₁ = 1 and n ₂ = 0, and A ₁ ⁺ is an ammonium group or In the case of a phosphonium group, n ₁ = n ₂ = 1.

In the formula, R ⁵ and R ⁶ may be the same or different, and are each an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group, a benzyl group, etc.) or an aryl group (for example, a phenyl group). 1-naphthyl group, etc.), and these groups may be substituted. Examples of the substituent in this case include a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, and the like. Group, alkyl group, aryl group, alkenyl group, alkynyl group, hydroxy group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, An alkylsulfonyl group, an arylsulfonyl group, etc. are mentioned. Further, R ⁵ and R ⁶ may be a group containing a phenyl group substituted by the vinyl group represented by the above general formula 1.

In the formula, R ⁷ , R ⁸ and R ⁹ may be the same or different, and are respectively synonymous with R ¹ , R ² and R ^{3 in the} above general formula 1. Among these groups, those in which R ⁷ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (for example, a methyl group, an ethyl group, etc.) and R ⁸ and R ⁹ are hydrogen atoms are particularly preferable. R ¹⁰ has the same meaning as R ⁴ in the above general formula 1. L ₂ and L ₃ each independently represent a polyvalent linking group consisting of an atom or a group of atoms selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom. is the same meaning as _{L 1} in. m ₂ represents an integer of 0 to 4, p ₂ represents an integer of 0 or 1, and q ₂ represents an integer of 1 to 4.

In addition, a ring structure in which an N atom, an S atom, a P atom, or the like forming an organic onium group represented by A ₁ ⁺ is combined with a group arbitrarily selected from R ⁵ , R ^6, L ₂ , and L ₃ (For example, a pyridinium ring, 2-quinolinium ring, morpholinium ring, piperidinium ring, pyrrolidinium ring, tetrahydrothiophenium ring, etc.) may be formed. These ring structures are halogen atoms, carboxyl groups, sulfo groups, nitro groups, cyano groups, amide groups, amino groups, alkyl groups, aryl groups, alkenyl groups, alkynyl groups, hydroxy groups, alkoxy groups, aryloxy groups, alkylthio groups. , Arylthio group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group and the like.

  Further, in the water-soluble polymer A of the present invention, in addition to the polymer having a repeating unit in which a phenyl group substituted with a vinyl group as described above is bonded to the main chain through a cationic group, a vinyl group It is also possible to use a polymer having a repeating unit in which a phenyl group substituted with is bonded directly or via a linking group containing no cationic group to the main chain and a repeating unit having a cationic group.

  Examples of the water-soluble polymer A in the present invention are shown below, but the present invention is not limited to these examples. The numbers in the exemplified structural formulas represent the weight percent of each repeating unit in 100 weight percent of the total copolymer composition.

  There is a preferred range for the proportion of each repeating unit constituting the water-soluble polymer A of the present invention in the entire polymer. As described above, when a phenyl group substituted with a vinyl group is bonded to the main chain via a cationic group, the proportion of the repeating unit in 100% by weight of the total polymer composition is 5% by weight or more. It is preferable that it is in the range of 10% by weight to 80% by weight.

  In the case of a polymer comprising a repeating unit in which a phenyl group substituted by a vinyl group is bonded to the main chain directly or via a linking group not containing a cationic group and a repeating unit having a cationic group, a vinyl group The ratio of the repeating unit having a substituted phenyl group is preferably in the range of 5 wt% to 70 wt%, particularly preferably in the range of 10 wt% to 50 wt%. The proportion of the repeating unit having a cationic group is preferably in the range of 30% by weight to 95% by weight, and particularly preferably in the range of 50% by weight to 90% by weight.

  When the water-soluble polymer A of the present invention is a copolymer with any water-soluble or water-insoluble monomer, the proportion of the repeating unit derived from the water-soluble monomer or water-insoluble monomer is 65 wt. % Or less, particularly preferably in the range of 40% by weight or less.

  There is a preferred range for the molecular weight of the water-soluble polymer A of the present invention, the weight average molecular weight is preferably in the range of 1,000 to 1,000,000, and more preferably in the range of 10,000 to 300,000. The water-soluble polymer A in the present invention may be used alone or in combination of two or more.

  Next, the water-soluble polymer (water-soluble polymer B) having a phenyl group substituted with a vinyl group in the side chain and a sulfonate group will be described in detail.

  The water-soluble polymer B of the present invention is a water-soluble polymer in which a phenyl group substituted with a vinyl group and a sulfonate group are bonded to the main chain either directly or via an arbitrary linking group. These linking groups are not particularly limited, and include any group, atom, or a combination thereof. The phenyl group substituted with the vinyl group and the sulfonate group may be independently bonded to the main chain, or the phenyl group substituted with the vinyl group and the sulfonate group share part or all of the linking group. You may combine in the form to do.

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

  More specifically, the water-soluble polymer B of the present invention has groups represented by the following general formulas 9 and 10 in the side chain.

^Wherein, R ^{11, R 12} and ^{R 13} may be different even in the same, have the same meanings as in ^R 1, ^{R 2} and ^{R 3} in the general formalized ^{1, R 14} is the It is synonymous with R ^{4 in the} general formula 1. L ₄ represents a polyvalent linking group consisting of an atom or a group of atoms selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically has the same meaning as L ₁ in Formula 1 above. is there. m ₃ represents an integer of 0 to 4, p ₃ represents an integer of 0 or 1, and q ₃ represents an integer of 1 to 4.

Among the groups represented by the above general formula, those in which R ¹¹ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.) and R ¹² and R ¹³ are hydrogen atoms are preferred. . The linking group L ₄ preferably includes a heterocyclic ring, and q ₃ is preferably 1 or 2.

In the formula, L ₅ represents a polyvalent linking group consisting of an atom or a group of atoms selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically, L ₁ in the general formula 1 above. It is synonymous with. Furthermore, L ₅ may share part or all of L _{4 in} the above general formula 9.

In the formula, X ⁺ represents a cation that supplies a charge necessary for neutralizing the sulfoanion, and may be monovalent or a divalent or higher polyvalent cation. Specific examples of such cations include alkali metal ions (eg, sodium, potassium, magnesium, lithium, calcium, barium, zinc, etc.), organic ammonium ions (eg, ammonium, triethylammonium, pyridinium, tetra-n-butylammonium, etc.). ), Iodonium ions (such as diphenyliodonium), sulfonium ions (such as triphenylsulfonium), and diazonium ions. Among these, alkali metal ions or organic ammonium ions are particularly preferable.

  The method for introducing a phenyl group substituted with a vinyl group in the polymer is not particularly limited. However, when a monomer having a phenyl group substituted with a vinyl group is polymerized, the vinyl group also reacts to form a gel. It is not preferable because it is expected to cause crystallization. Therefore, it is particularly preferable to synthesize a precursor polymer having no phenyl group substituted with a vinyl group, and then introduce a phenyl group substituted with the vinyl group by a conventionally known polymer reaction.

  The method for introducing the sulfonate group into the polymer is not particularly limited, and a monomer having the sulfonate group may be copolymerized, or a precursor polymer having no sulfonate group is synthesized, Thereafter, the sulfonate group may be introduced by a conventionally known polymer reaction.

  The water-soluble polymer B of the present invention may be a polymer composed only of the above-mentioned repeating unit having a phenyl group substituted with a vinyl group in the side chain and a repeating unit having a sulfonate group, or the present invention. As long as the effect of the above is not hindered, a polymer into which another repeating unit is further introduced may be used. Furthermore, it may be a copolymer with another monomer, and specific examples of such a monomer include all the water-soluble monomers and water-insoluble monomers exemplified in the water-soluble polymer A. One type of monomer may be used, or two or more types may be used.

  Examples of the water-soluble polymer B of the present invention are shown below, but the present invention is not limited to these examples. The numbers in the exemplified structural formulas represent the weight percent of each repeating unit in 100 weight percent of the total copolymer composition.

  In the water-soluble polymer B of the present invention, a repeating unit in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or via an arbitrary polyvalent linking group, and a sulfonate group is an arbitrary polyvalent linking group There is a preferred range for the proportion of the repeating units bonded to the main chain via the total polymer. The proportion of the repeating unit in which the phenyl group substituted by the vinyl group is bonded to the main chain directly or via any polyvalent linking group in 100% by weight of the total polymer composition is 5% to 70% by weight. It is preferably in the range, and particularly preferably in the range of 10% to 50% by weight. The proportion of the repeating unit in which the sulfonate group is bonded to the main chain via an arbitrary polyvalent linking group is preferably in the range of 10% by weight to 95% by weight, and 30% by weight to 90% by weight. It is especially preferable that it is in the range.

  When the water-soluble polymer B of the present invention is constituted with other arbitrary repeating units, the ratio of the other repeating units is preferably 65% by weight or less, and is in the range of 40% by weight or less. Is particularly preferred.

  The weight average molecular weight of the water-soluble polymer B of the present invention is preferably in the range of 1,000 to 1,000,000, and more preferably in the range of 10,000 to 300,000. The water-soluble polymer B in the present invention may be used alone or in combination of two or more.

  There is a preferred range for the solubility of the water-soluble polymers A and B of the present invention described above in water. That is, 0.5 g or more of the water-soluble polymer is preferably dissolved in 100 ml of ion-exchanged water at 25 ° C., more preferably 2.0 g or more.

  The photosensitive composition of the present invention can be used by mixing any known various binder resins in addition to the water-soluble polymer A or B described above. The binder resin in this case is not particularly limited, and specifically, a polymer arbitrarily composed of all the monomers exemplified above, polyvinylphenol, phenol resin, polyhydroxybenzal, gelatin, polyvinyl alcohol, carboxy Examples thereof include cellulose resins such as methylcellulose, polyimide resins, and the like. These binder resins are preferably water-soluble, and are water-soluble binder resins using at least one or more water-soluble monomers as exemplified above, and water-soluble binder resins such as gelatin, polyvinyl alcohol, and carboxymethyl cellulose. Is preferred.

  In the prior art, when using radical photopolymerization, it is necessary to provide a resin such as polyvinyl alcohol which is easily affected by oxygen in the atmosphere and generally has an oxygen barrier property as an overlayer on the surface of the photosensitive layer. there were. Moreover, in order to accelerate | stimulate or complete superposition | polymerization after exposure, it was necessary to heat-process for about several minutes at the temperature of about 100 degreeC.

  In contrast, the water-soluble polymer having a phenyl group substituted with a vinyl group of the present invention gives a photosensitive composition that is sufficiently photocured without providing an overlayer as described above, and is heat-treated after exposure. It is a feature that it is not necessary to carry out. Furthermore, it is mentioned as a feature that a highly sensitive photosensitive composition can be obtained by using a photopolymerization initiator or photoacid generator in combination with a sensitizing dye. Further, the photosensitive composition of the present invention has an advantage that the latent image regression is extremely small.

  In the photosensitive composition using the water-soluble polymer A or B of the present invention, a phenyl group substituted with a vinyl group in the polymer is exposed to a photopolymerization initiator or a photoacid in an exposed portion (region exposed to light). Crosslinking is effected by the action of the generator to render it water-insoluble. On the other hand, in the unexposed areas (areas not exposed to light), the water solubility becomes extremely high by introducing a cationic group or a sulfonate group. Therefore, the unexposed portion (non-image portion) is dissolved and removed by water development, while the exposed portion (image portion) remains undissolved to form a relief image. The photosensitive composition of the present invention is characterized by extremely high water-solubility in the unexposed area, which is rapidly dissolved and removed by water development, and the exposed area has stable water development suitability due to improved image strength and hydrophobicity. And high resolution can be obtained. In particular, when the photosensitive composition of the present invention is used in a lithographic printing plate, the ink acceptability in the image area, which was difficult with a conventional water development type lithographic printing plate, is remarkably improved, and the anti-resisting property. The effect of excellent printing force is manifested.

  In the prior art, it has been known that the similar polymerization activity of the styrene monomer is extremely low compared to the photopolymerization of the (meth) acrylate monomer by the radical generator. For example, reference is made to page 46 of Takahiro Tsunoda, “Photosensitive Resin”, published by the Printing Society Publishing Department, 1975. However, the present invention has found that a photosensitive composition capable of high sensitivity and water development can be obtained by using a water-soluble polymer into which a phenyl group substituted with a vinyl group which is a styrene type is used. Is. A very important effect of the photosensitive composition of the present invention is that crosslinking can be performed without being affected by oxygen in the air. Furthermore, it has been found that a photosensitive composition capable of being developed with high sensitivity and water can be obtained by using a photoacid generator.

  The photosensitive composition of the present invention contains a photopolymerization initiator or a photoacid generator in combination with the water-soluble polymer A or B described above. 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-62-81345, and JP-A-2-211452 p-di (dimethylaminobenzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, described in JP-B-2-9596 Acyl phosphines, thioxanthones described in JP-B-63-61950, and 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 JP-B Nos. 52-14277, 52-14278, and 52-14279.

  (C) Examples of the organic peroxide include almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. For example, 3,3 ′, 4,4′-tetra- (tert -Butylperoxycarbonyl) 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 ′ -Peracids such as tetra (p-isopropylcumylperoxycarbonyl) benzophenone, di-tert-butyldiperoxyisophthalate Ester is preferable.

  (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'-teto Phenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluoromethylphenyl) -4,4 ', 5,5'-tetraphenylbiimidazole and the like.

  (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.

  (F) Examples of azinium salt compounds are described in JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, JP-B-46-42363, etc. And a group of compounds having the N—O bond.

  (G) Examples of active ester compounds include imide sulfonate compounds described in JP-B-62-2223, etc., and active sulfonates described in JP-B-63-14340, JP-A-59-174831, etc. Can do.

  (H) Examples of metallocene compounds include those described in JP-A Nos. 59-152396, 61-151197, 63-41484, 2-249, and 2-4705. Examples thereof include titanocene compounds and iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.

  (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 No. 3,987,037, No. 4,189,323, JP-A Nos. 61-151644, 63-298339, No. 4-69661, No. 11-15359, etc. Trihalomethyl-s-triazine compounds described in JP-A Nos. 54-74728, 55-77742, 60-138539, 61-143748, 4-362644, 11-11 And 2-trihalomethyl-1,3,4-oxadiazole derivatives described in Japanese Patent No. 84649. 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 are described in JP-A-8-217813, JP-A-9-106242, JP-A-9-188865, JP-A-9-188686, JP-A-9-188710, and the like. Organic boron ammonium compounds, organic boron sulfonium compounds and organic boron oxosulfonium compounds described in JP-A-6-175561, JP-A-6-175564, JP-A-6-157623, etc., JP-A-6-175553, Organoboron iodonium compounds described in JP-A-6-175554, etc., organoboron phosphonium compounds described in JP-A-9-188710, etc., JP-A-6-348011, JP-A-7-128785, JP-A-7-140589. No. 7, 7-292014, 7-306527, etc. Coordination complex compounds. Moreover, cationic dyes containing an organic boron anion as the counter anion described in JP-A-62-143044 and JP-A-5-194619 can be mentioned.

  As the photoacid generator used in the present invention, any compound can be used as long as it is a compound capable of decomposing by irradiation with light or electron beam and generating a strong acid such as hydrochloric acid or sulfonic acid or an acid such as Lewis acid. it can. Examples of photoacid generators that can be used in the present invention include (k) aromatic diazonium salt compounds, (l) p-valic acid-o-nitrobenzyl ester, benzenesulfonic acid-o-nitrobenzyl ester, o- Sulfonic acid ester derivatives such as nitrobenzyl esters, (m) 9,10-dimethoxyanthracene-2-sulfonic acid-4-nitrobenzyl ester, pyrogallol trismethanesulfonate, naphthoquinonediazide-4-sulfonic acid esters, (n) Sulfones such as dibenzylsulfone and 4-chlorophenyl-4′-methoxyphenyldisulfone, (o) phosphoric acid ester derivatives and (p) US Pat. No. 3,332,936, JP-A-2-83638, and JP-A-11 -322707, 2000-1469, etc. Azometan compounds and the like.

  When the photosensitive composition in the present invention is adapted to light having a short wavelength of 450 nm or less, both the above-mentioned photopolymerization initiator and photoacid generator can be preferably used. ) Aromatic onium salt compound, (g) active ester compound, (h) metallocene compound, (i) trihaloalkyl-substituted compound, (j) organic boron salt compound, (k) aromatic diazonium salt compound, (m) sulfonic acid Ester derivatives and (p) sulfonyldiazomethane compounds are preferred.

  Moreover, when making the photosensitive composition of this invention respond | correspond to visible light of 450 nm-750 nm, (b) aromatic onium salt compound, (h) metallocene compound, (i) trihaloalkyl substituted compound, (j) Organic boron salt compounds and (k) aromatic diazonium salt compounds are particularly preferred.

  Moreover, when making the photosensitive composition of this invention respond | correspond to near-infrared-infrared light more than 750 nm, (b) aromatic onium salt compound, (i) trihaloalkyl substituted compound, (j) organoboron salt Compounds are particularly preferred.

  The photopolymerization initiator and photoacid generator may be used alone or in any combination of two or more. Further, any photopolymerization initiator and any photoacid generator can be used in combination. 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 and the photoacid generator is preferably 1 to 100% by weight, more preferably 1 to 40% by weight, based on the water-soluble polymer.

  As another preferable element constituting the photosensitive composition in the present invention, a polymerizable monomer having a polymerizable unsaturated bond group in the molecule can be exemplified. The polymerizable unsaturated bond group represents an ethylenically unsaturated double bond group that can contribute to a photopolymerization reaction or a photocrosslinking reaction by the action of a photopolymerization initiator or a photoacid generator. In particular, it is preferable to use a polyfunctional polymerizable monomer having two or more polymerizable unsaturated bond groups in the molecule. Examples of such polymerizable monomers include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trisacryloyloxyethyl isocyanurate, tripropylene. Polyfunctional acrylate monomers such as glycol diacrylate, ethylene glycol glycerol triacrylate, glycerol epoxy triacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc. Methacrylate monomers, as well as itaconic acid monomers, crotonic acid monomers , Maleic acid ester monomers.

  Examples of other polymerizable monomers include styrene derivatives. The styrene derivative is preferably a compound having two or more vinylphenyl groups in the molecule. For example, 1,4-divinylbenzene, 1,4-diisopropenylbenzene, 1,4-bis (4-vinylbenzyloxy) benzene, 1,2,3-tris (4-vinylbenzyloxy) benzene, 3,5-tris (4-vinylbenzyloxy) benzene, 2,2-bis [4- (4-vinylbenzyloxy) phenyl] propane, 1,1,2,2-tetrakis [4- (4-vinylbenzyl) Oxy) phenyl] ethane, α, α, α ′, α′-tetrakis [4- (4-vinylbenzyloxy)] p-xylene, 1,2-bis (4-vinylbenzylthio) ethane, 1,4- Bis (4-vinylbenzylthio) butane, bis [2- (4-vinylbenzylthio) ethyl] ether, 2,5-bis (4-vinylbenzylthio) -1,3,4-thiadiazole, 2 4,6-tris (4-vinylbenzylthio) -1,3,5-triazine, N, N-bis (4-vinylbenzyl) -N-methylamine, N, N, N ′, N′-tetrakis ( 4-vinylbenzyl) -1,2-diaminoethane, N, N, N ′, N′-tetrakis (4-vinylbenzyl) p-phenylenediamine, maleic acid bis (4-vinylbenzyl) ester, and the like.

  Alternatively, a polymerizable oligomer having radical polymerizability can be preferably used instead of the above polymerizable monomer. For example, polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate and the like can be used in the same manner as the polymerizable monomer as various oligomers into which acryloyl group and methacryloyl group are introduced.

  There is a preferred range for the ratio of the polymerizable monomer or polymerizable oligomer as described above to the water-soluble polymer of the present invention. That is, the polymerizable monomer or polymerizable oligomer is preferably in the range of 0.01 to 10 parts by weight, more preferably in the range of 0.05 to 1 part by weight with respect to 1 part by weight of the polymer.

  Next, the photosensitive composition of aspect (2) of this invention is demonstrated. The photosensitive composition contains a cationic monomer (hereinafter abbreviated as a cationic monomer) having two or more polymerizable unsaturated bond groups in the molecule, a polymer, and a photopolymerization initiator or photoacid generator.

  Since the cationic monomer of the present invention has two or more polymerizable unsaturated bond groups in the molecule, a negative photosensitive material with improved cross-linking efficiency in the exposed area, high sensitivity and improved image intensity can be obtained. Can be produced. In particular, when water development is performed, it is advantageous in that the water-solubility becomes extremely high by introducing a cationic group in the unexposed area and water development can be performed rapidly.

  The cationic monomer of the present invention will be described in detail. The cationic monomer has at least one cationic group. A compound containing 1 to 4 cationic groups is preferred. The cationic group is a group selected from organic onium groups such as an ammonium group, a sulfonium group, a phosphonium group, an iodonium group, and an oxonium group, and among these, a quaternary ammonium group is most preferably used.

  The polymerizable unsaturated bond group in the present invention represents an ethylenically unsaturated double bond group that can contribute to a photopolymerization reaction or a photocrosslinking reaction by the action of a photopolymerization initiator or a photoacid generator. This polymerizable unsaturated bond group is bonded to the organic onium group through an arbitrary linking group. That is, a preferable cationic monomer in the present invention has 1 to 4 organic onium groups, and a total of two or more polymerizable unsaturated bond groups are composed of an arbitrary primitive group. A compound bonded through a linking group.

  More specifically, a preferred representative example of the cationic monomer of the present invention has at least one unit structure represented by the following general formula 17.

In the formula, A ₂ ⁺ represents an organic onium group selected from an ammonium group, a sulfonium group, a phosphonium group, an iodonium group, and an oxonium group. R ¹⁵ , R ¹⁶ and R ¹⁷ may be the same or different and have the same meanings as R ¹ , R ² and R ^{3 in the} above general formula 1, respectively. Among these groups, those in which R ¹⁵ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (for example, a methyl group, an ethyl group, etc.) and R ¹⁶ and R ¹⁷ are hydrogen atoms are particularly preferable. L ₆ represents a polyvalent linking group consisting of an atom or a group of atoms selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically has the same meaning as L ₁ in Formula 1 above. is there.

Wherein, _{q 4} is an integer of 1-4. However, when the cationic monomer of the present invention contains only one unit structure represented by the above general formula in one molecule, q ₄ is an integer of 2 to 4, and the unit structure is 2 in one molecule. When more than one are included, the organic onium groups are bonded via any multivalent linking group. Examples of the linking group include the linking group described in the above L ₁ , and a ring structure (for example, a pyridinium ring) formed by combining this linking group with an N atom, an S atom, a P atom, or the like forming an organic onium group. , 2-quinolinium ring, morpholinium ring, piperidinium ring, pyrrolidinium ring, tetrahydrothiophenium ring, etc.). These ring structures are halogen atoms, carboxyl groups, sulfo groups, nitro groups, cyano groups, amide groups, amino groups, alkyl groups, aryl groups, alkenyl groups, alkynyl groups, hydroxy groups, alkoxy groups, aryloxy groups, alkylthio groups. , Arylthio group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group and the like.

  Specific examples of the cationic monomer having two or more polymerizable unsaturated bonding groups in the molecule according to the present invention are shown below, but are not limited thereto.

  As the polymerizable unsaturated bond group introduced into the cationic monomer of the present invention, a phenyl group substituted with a vinyl group and a heterocyclic group substituted with a vinyl group (for example, a pyridine ring, a quinoline ring, etc.) are preferable. When these polymerizable unsaturated bonding groups are introduced, the sensitivity becomes extremely high in combination with various photopolymerization initiators or photoacid generators, and is hardly affected by oxygen.

  The addition amount of the cationic monomer of the present invention is preferably included in the range of 0.01 to 10 parts by weight and more preferably in the range of 0.05 to 1 part by weight with respect to 1 part by weight of the polymer. It is particularly preferred that it be included.

  The polymer used together with the cationic monomer of the present invention is not particularly limited, and various known polymers can be used. Specifically, a polymer arbitrarily composed of all the monomers exemplified in the embodiment (1) of the present invention can be used.

  As examples of the polymer other than the above examples, polyvinyl phenol, phenol resin, polyhydroxybenzal, gelatin, polyvinyl alcohol, cellulose resin such as carboxymethyl cellulose, polyimide resin, and the like can also be used.

  Furthermore, the polymer is preferably water-soluble. Therefore, a water-soluble polymer using at least one water-soluble monomer exemplified in the embodiment (1) of the present invention, or a water-soluble binder such as gelatin, polyvinyl alcohol, carboxymethyl cellulose or the like is preferable.

  Among the polymers used together with the cationic monomer of the present invention, the water-soluble polymer A or B mentioned in the embodiment (1) of the present invention is preferable, and the water-soluble polymer A is particularly preferable. By using both the cationic monomer of the present invention and the water-soluble polymer A or B, a relief image with high sensitivity and high printing durability can be obtained, and further, the latent image regression is greatly improved.

  The polymer used here may be used alone or as a mixture of any two or more selected from the above-mentioned polymers.

  As the photopolymerization initiator or photoacid generator used together with the cationic monomer and polymer of the present invention, the compounds mentioned in the embodiment (1) of the present invention can be used singly or in combination of two or more kinds. .

  When making the photosensitive composition comprised from the cationic monomer and polymer of this invention respond | correspond to short wavelength light of 450 nm or less, (b) aromatic onium salt as a photoinitiator or a photoacid generator Compound, (g) active ester compound, (h) metallocene compound, (i) trihaloalkyl-substituted compound, (j) organoboron salt compound, (k) aromatic diazonium salt compound, (m) sulfonic acid ester derivative, (p ) A sulfonyldiazomethane compound is preferably used.

  Moreover, when making the said photosensitive composition respond | correspond to visible light of 450 nm-750 nm, (b) aromatic onium salt compound, (h) metallocene compound, (i) as a photoinitiator or a photoacid generator Trihaloalkyl-substituted compounds, (j) organic boron salt compounds, and (k) aromatic diazonium salt compounds are particularly preferably used.

  Furthermore, in the case of dealing with near infrared to infrared light of 750 nm or more, (b) an aromatic onium salt compound, (i) a trihaloalkyl-substituted compound, (j) as a photopolymerization initiator or a photoacid generator An organic boron salt compound is particularly preferably used.

  Among the photopolymerization initiators and photoacid generators described above, in particular, when (i) a trihaloalkyl-substituted compound and (j) an organic boron salt compound are used in combination, it is preferable because sensitivity is greatly improved. The content of the photopolymerization initiator and the photoacid generator is preferably included in the range of 1 to 100% by weight, more preferably 1 to 40% by weight, based on the polymer.

  Among the photosensitive compositions of the above-described aspects (1) and (2) of the present invention, the photosensitive composition using the water-soluble polymer B is particularly preferable because the strength of the image area is particularly excellent. When the photosensitive composition comprising the water-soluble polymer B is used as a lithographic printing plate, it is particularly suitable for printing on a printing press without performing a development process, and has excellent printing durability. A lithographic printing plate precursor can be obtained.

  The photosensitive composition of the present invention has absorption in the wavelength region from visible light to infrared light so that it can correspond to various light sources from visible light to infrared light, and the above-mentioned photopolymerization initiator or photoacid generator. It is preferable to also contain a sensitizer that sensitizes. As the sensitizer, various sensitizing dyes are preferably used. Such sensitizing dyes include cyanine, phthalocyanine, merocyanine, coumarin, porphyrin, spiro compound, ferrocene, fluorene, fulgide, imidazole, perylene, phenazine, phenothiazine, polyene, azo compound, diphenylmethane, triphenylmethane, polymethine, acridine, Coumarin, ketocoumarin, quinacridone, indigo, styryl, squarylium compound, pyrylium compound, thiopyrylium compound, and further, European Patent No. 0,568,993, US Patent Nos. 4,508,811, and 5,227,227. The compounds described in No. Gazette and the like can also be used.

In recent years, output machines equipped with a blue semiconductor laser having an oscillation wavelength of 400 to 430 nm have been developed. This output machine has a maximum exposure energy amount of about several tens of μJ / cm ² , and the photosensitive material used is required to have high sensitivity. The photosensitive composition of the present invention can cope with this output machine by using the above-mentioned sensitizing dyes in combination. Among the sensitizing dyes described above, a pyrylium compound or a thiopyrylium compound is preferable for a blue semiconductor laser.

  In addition, the photosensitive composition of the present invention is very suitably used for scanning exposure using laser light in the near-infrared to infrared light, that is, 700 nm or more, and further 750 to 1100 nm wavelength region. Preferred examples of the sensitizing dye used for such purposes include US Pat. No. 4,973,572, JP-A-10-230582, JP-A-11-153589, JP-A-2000-103179, and JP-A-2000-187322. And the like. Among these, particularly preferred sensitizing dyes include cyanine dyes, polymethine dyes, and squarylium dyes.

  There is a preferable range for the content of the sensitizing dye as described above, and it is preferable to add in the range of 1 to 300 mg per square meter of the photosensitive composition, and further, 5 to 200 mg per square meter of the photosensitive composition. It is particularly preferable to add in a range.

  In the photosensitive composition of the present invention, other components may be preferably added for various purposes in addition to the components described above. In particular, it is preferable to add various polymerization inhibitors for the purpose of preventing thermal polymerization or thermal crosslinking of the polymerizable unsaturated bonding group and improving the long-term storage stability. As the polymerization inhibitor in this case, compounds having various phenolic hydroxyl groups such as hydroquinones, catechols, naphthols, and cresols, quinone compounds, and the like are preferably used, and hydroquinone is particularly preferably used. In this case, the addition amount of the polymerization inhibitor is preferably in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the polymer.

  As another element constituting the photosensitive composition, a colorant can also be preferably added. As the colorant, it is used for the purpose of enhancing the visibility of the image area after exposure and development processing, such as carbon black, phthalocyanine dye, triarylmethane dye, anthraquinone dye, azo dye, etc. These dyes and pigments can be used, and it is preferably used in the range of 0.005 to 0.5 parts by weight with respect to 1 part by weight of the polymer.

  About the element which comprises a photosensitive composition, another element can also be added and added for various purposes besides the above-mentioned element. For example, inorganic fine particles or organic fine particles are also preferably added for the purpose of preventing blocking of the photosensitive composition or improving the sharpness of an image after development.

  The photosensitive layer is produced by applying a coating liquid of a photosensitive composition comprising the above-described elements onto a support and drying. Various known methods can be used as the coating method, and examples thereof include bar coater coating, curtain coating, blade coating, air knife coating, roll coating, spin coating, and dip coating. Regarding the thickness of the photosensitive layer itself when used as a lithographic printing plate, it is preferably formed on the support with a dry thickness in the range of 0.5 μm to 10 μm, and more preferably in the range of 1 μm to 5 μm. Is preferable in order to greatly improve.

  Various known supports can be used as the support to which the coating liquid of the photosensitive composition is applied. Examples thereof include paper, polyethylene-coated paper, film, metal plate and the like. When using the photosensitive composition of this invention as a lithographic printing plate, since the support surface of an unexposed part turns into a non-image part, the support body which has a hydrophilic surface is used. As a support for this purpose, a roughened aluminum plate having an anodized film and a plastic film having a hydrophilic surface are particularly preferably used.

  A suitable aluminum plate used as a support for the lithographic printing plate of the present invention has a mechanical surface roughening and a chemical surface roughening for the purpose of improving the adhesion with the photosensitive layer and imparting water retention to the non-image area. Then, the surface is roughened by electrochemical roughening or the like, and then anodized. In addition, various hydrophilization treatments and sealing treatments are performed as necessary, and examples of such hydrophilization treatments include silicate treatment using an alkali metal silicate aqueous solution, treatment with potassium fluoride zirconate, Examples thereof include treatment with polyvinylphosphonic acid. In particular, when printing is performed without developing, it is particularly preferable to use a silicate-treated aluminum plate in order to improve removability and water retention of non-image areas.

  Suitable plastic films used as the support for the lithographic printing plate of the present invention include, for example, polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, cellulose diacetate, cellulose triacetate, and cellulose propionate. , Cellulose butyrate, cellulose nitrate and the like. The surface of these plastic films is subjected to various hydrophilization treatments for the purpose of improving the adhesion with the photosensitive layer and imparting water retention to the non-image area. Such hydrophilic treatment includes chemical treatment, discharge treatment, glow discharge treatment, flame treatment, ultraviolet treatment, high-frequency treatment, active plasma treatment, laser treatment, and other surface treatments, and a hydrophilic layer is coated on the surface. The method etc. are mentioned, You may implement these processes in combination. When used as a lithographic printing application, printing durability is required, so the hydrophilic surface must be firmly bonded to the plastic film. For this reason, a method of applying a hydrophilic layer which does not dissolve or swell in water after chemical and physical surface treatment is applied to the plastic film, and increases the binding force is particularly preferably performed.

  As the hydrophilic layer coated on the surface of the plastic film, a conventionally known layer can be used. For example, hydrophilicity by a (meth) acrylate-based polymer having a hydroxyalkyl group described in JP-B-49-2286. Hydrophilic resin layer, a hydrophilic layer composed of a urea resin and a pigment described in JP-B-56-2938, and a hydrophilic layer obtained by curing an acrylamide polymer described in JP-A-48-83902 with an aldehyde. A hydrophilic layer obtained by curing a composition containing a water-soluble melamine resin, polyvinyl alcohol and a water-insoluble inorganic powder described in JP-A-62-280766, JP-A-8-184967 A hydrophilic layer obtained by curing a water-soluble polymer containing a repeating unit having an amidino group in the side chain as described, JP-A-8-2720 A hydrophilic layer containing a hydrophilic (co) polymer described in No. 7 and cured with hydrolyzed tetraalkylorthosilicate, a hydrophilic layer having an onium group described in JP-A-10-296895, A hydrophilic layer obtained by three-dimensionally cross-linking a crosslinked hydrophilic polymer having a Lewis base moiety described in JP-A No. 11-311861 by interaction with a polyvalent metal ion, described in JP-A No. 2000-122269 Examples include a hydrophilic layer containing a hydrophilic resin and a water-dispersible filler. Further, for the purpose of increasing the bonding force between the plastic film surface and the hydrophilic layer disclosed in JP-A-57-179852, 2001-166491, etc., both are chemically bonded by surface graft polymerization or the like. A support can also be preferably used.

  The photosensitive composition having the photosensitive layer formed on the support as described above is subjected to contact exposure or laser scanning exposure, and then subjected to pattern formation by removing unexposed portions with a developer. The exposed portion is cross-linked, so that the solubility in a developing solution is lowered and an image portion is formed.

  A significant feature of the photosensitive composition of the present invention is that it can be developed with water. The developer used for water development is substantially free of an alkali agent unlike a strong alkali developer (usually exceeding pH 10) which contains a large amount of an alkali agent generally used in the past. Therefore, the pH of the developer used in the water development of the present invention is 10 or less, preferably pH 9.5 or less, and more preferably pH 9 or less. The lower limit of pH is about 3. In the developer used in the water development of the present invention, water accounts for 70% by weight or more, more preferably 80% by weight or more of the whole developer, and other additives include ethanol, isopropanol, and n-butyl cellosolve. In addition, various organic solvents such as ethylene glycol, diethylene glycol, triethylene glycol, glycerin, and benzyl alcohol, or anionic, cationic, and nonionic surfactants can be added.

  Further, when the photosensitive composition of the present invention is applied to a lithographic printing plate, the greatest feature is that printing can be performed without performing development processing. As an aspect in this case, there is an aspect in which a lithographic printing plate is exposed to a printing machine and printed immediately without performing development processing, and an aspect in which the lithographic printing plate is exposed to a printing machine and immediately printed. . In these cases, the unexposed photosensitive layer that has not been crosslinked by ink, dampening water, or the like swells, is transferred to paper, a blanket roll, or the like, and is removed from the support at an early stage of printing. The ink is not deposited on the surface of the support exposed by removing the photosensitive layer, and a non-image portion is formed. The photosensitive layer in the exposed area is cross-linked and cured, so that the ink deposits and forms a printed image. That is, when the photosensitive composition of the present invention is used as a lithographic printing plate, printing can be performed without particularly performing development processing or other processing.

  Next, typical synthesis examples of the water-soluble polymer and the cationic monomer of the present invention will be given, but other exemplified compounds can be easily synthesized by referring to the same method or a conventionally known method as described above. be able to.

Synthesis example 1
Synthesis Example of Polymer (CP-1) Poly (4-vinylpyridine) [manufactured by ALDRICH CHEMICAL COMPANY, INC., Average molecular weight 60,000] 21.0 g, 4-tert-butylcatechol [manufactured by Tokyo Chemical Industry Co., Ltd.] 0.2 g of 4-chloromethylstyrene (Seimi Chemical Co., Ltd., CMS-14) 18.3 g was dissolved in methanol, and the mixture was stirred for 8 hours under reflux in a hot water bath. After completion of the reaction, methanol was distilled off under reduced pressure, and the residue became a solid when repeated washing with ethyl acetate. This was collected by filtration and dried to obtain 38.3 g of a white solid.

Synthesis example 2
Synthesis Example of Polymer (CP-2) Poly (4-vinylpyridine) [manufactured by ALDRICH CHEMICAL COMPANY, INC., Average molecular weight 60,000] 21.0 g, 4-tert-butylcatechol [manufactured by Tokyo Chemical Industry Co., Ltd.] 0.2g, 4-chloromethyl styrene [Seimi Chemical Co., Ltd. product, CMS-14] 15.3g was melt | dissolved in methanol, Then, it stirred under recirculation | reflux for 8 hours on the hot water bath. Next, 27.9 g of methyl-p-toluenesulfonate [manufactured by Tokyo Chemical Industry Co., Ltd.] was added and stirred for 6 hours under reflux. After completion of the reaction, methanol was distilled off under reduced pressure, and the residue became a solid when repeated washing with ethyl acetate. This was collected by filtration and dried to obtain 55.2 g of milky white solid.

Synthesis example 3
Synthesis of polymer (CP-6) 17.8 g of N, N-dimethylacrylamide [manufactured by Tokyo Chemical Industry Co., Ltd.] and 12.6 g of 4-vinylpyridine [manufactured by Tokyo Chemical Industry Co., Ltd.] were dissolved in 70 g of isopropanol. The mixture was heated and stirred on a hot water bath in a nitrogen atmosphere. The internal temperature was kept at 75 ° C., and 0.3 g of 2,2′-azobisisobutyronitrile [manufactured by Tokyo Chemical Industry Co., Ltd.] was added. The polymerization reaction was carried out for 7 hours at the same temperature. After completion of the polymerization reaction, N-nitrosophenylhydroxylamine ammonium salt [Wako Pure Chemical Industries, Ltd., Q-1300] 0.3 g, 4-chloromethylstyrene [Seimi Chemical Co., Ltd., CMS-14] 20. 2 g and 50 g of methanol were added, and the mixture was stirred for 8 hours under reflux on a hot water bath. After completion of the reaction, the reaction solution was poured into ethyl acetate and washed with ethyl acetate to give a solid. This was collected by filtration and dried to obtain 40.2 g of a light green solid.

Synthesis example 4
Synthesis of cationic monomer (CM-14) 4,4′-bipyridine [manufactured by Tokyo Chemical Industry Co., Ltd.] 15.6 g, 4-tert-butylcatechol [manufactured by Tokyo Chemical Industry Co., Ltd.] 0.4 g, 4- 33.6 g of chloromethylstyrene [manufactured by Seimi Chemical Co., Ltd., CMS-14] was dissolved in 500 ml of ethanol and stirred for 30 hours under reflux in a hot water bath. After the reaction was completed, the precipitated crystals were collected by filtration, washed with ethanol, and dried to obtain 25.5 g of a yellow solid.

Synthesis example 5
Synthesis of raw material monomer (SM-1) 2,5-dimercapto-1,3,4-thiadiazole [Tokyo Chemical Industry Co., Ltd., Bismuthiol] 357.6 g (2.38 mol) was suspended in methanol 1.2 kg. While stirring under water cooling, 234.0 g (2.31 mol) of triethylamine [manufactured by Nacalai Tesque Co., Ltd.] was added over 20 minutes. While stirring the obtained yellow-orange uniform solution under water cooling, 305.2 g (2.00 mol) of 4-chloromethylstyrene [manufactured by Seimi Chemical Co., Ltd., CMS-14] was added dropwise over 1 hour. After completion of dropping, stirring was continued for 2 hours at the same temperature. After completion of the reaction, the precipitated crystals were collected by filtration and washed thoroughly with methanol. This was dried and the raw material monomer (SM-1) represented by the following structural formula 21: 2- (4-vinylbenzylthio) -5-mercapto-1,3,4-thiadiazole as yellowish white crystals 357. 0 g (yield 67%) was obtained.

Synthesis of Intermediate Polymer (SM-2) 266.4 g (1.00 mol) of the raw material monomer (SM-1) obtained above was suspended in a mixed solvent of 710.4 g of ethanol and 177.6 g of ion-exchanged water, While stirring at room temperature, 121.5 g (1.20 mol) of triethylamine [manufactured by Nacalai Tesque Co., Ltd.] was added over 20 minutes. The obtained yellow uniform solution was heated and stirred on a hot water bath in a nitrogen atmosphere to adjust the internal temperature to 75 ° C. At the same temperature, 2.0 g of 2,2′-azobisisobutyronitrile [manufactured by Tokyo Chemical Industry Co., Ltd.] was added to initiate polymerization. A polymerization reaction was performed for 8 hours to obtain a yellow uniform solution containing an intermediate polymer (SM-2) represented by the following structural formula 22. In this solution, 2.0 g of N-nitrosophenylhydroxylamine ammonium salt [Q-1300, manufactured by Wako Pure Chemical Industries, Ltd.] was dissolved as a polymerization inhibitor, and the next reaction polymer (SP-9) was synthesized as it was. Used for.

Synthesis of Polymer (SP-9) The whole solution containing the intermediate polymer (SM-2) obtained above was heated and stirred on a hot water bath, and the internal temperature was adjusted to 50 ° C. At the same temperature, 73.3 g (0.60 mol) of propane sultone [manufactured by Tokyo Chemical Industry Co., Ltd.] was added and reacted for 3 hours. Subsequently, 73.3 g (0.48 mol) of 4-chloromethylstyrene [manufactured by Seimi Chemical Co., Ltd., CMS-14] was added, and the mixture was further reacted for 3 hours. After completion of the reaction, the reaction solution was poured into 1.0 kg of diisopropyl ether to precipitate a pale yellow polymer. The supernatant was discarded by decantation. The remaining polymer was dissolved in 1.0 kg of methanol and poured into 1.0 kg of diisopropyl ether for reprecipitation. After thoroughly washing the remaining polymer with acetone, 2.0 g of N-nitrosophenylhydroxylamine ammonium salt [Q-1300, manufactured by Wako Pure Chemical Industries, Ltd.] was added as a polymerization inhibitor. It dissolved in methanol so that it might become 0.5 kg, and the methanol solution of the target polymer (SP-9) was obtained. As a result of measuring the solid content of this solution, it was 29%, and it was found that the polymer yield was 435 g and the polymer yield was 97%. As a result of measuring the molecular weight of the obtained polymer (SP-9) by gel permeation chromatography, it was found to be a polymer having a weight average molecular weight of 65000 (polystyrene conversion).

Synthesis Example 6
Synthesis of Polymer (SP-12) 20.9 g (78.4 mmol) of raw material monomer (SM-1) obtained in Synthesis Example 5 and sulfopropyl methacrylate-potassium salt [manufactured by Tokyo Chemical Industry Co., Ltd.] 50.0 g (203.0 mmol), 20.0 g of n-butyl methacrylate [manufactured by Tokyo Chemical Industry Co., Ltd.] was suspended in a mixed solvent of 250.0 g of ethanol and 50.0 g of ion-exchanged water, and triethylamine [Nacalai] with stirring at room temperature. 9.5 g (94.1 mmol) from Tesque Corporation] was added. The obtained yellow uniform solution was heated and stirred on a hot water bath in a nitrogen atmosphere to adjust the internal temperature to 75 ° C. At the same temperature, 2,2′-azobisisobutyronitrile [manufactured by Tokyo Chemical Industry Co., Ltd.] (1.0 g) was added, and a polymerization reaction was performed for 8 hours. After completion of the polymerization reaction, 2.0 g of N-nitrosophenylhydroxylamine ammonium salt [Q-1300, manufactured by Wako Pure Chemical Industries, Ltd.] as a polymerization inhibitor was dissolved in the reaction solution, and the internal temperature was adjusted to 50 ° C. At the same temperature, 14.4 g (94.1 mmol) of 4-chloromethylstyrene [manufactured by Seimi Chemical Co., Ltd., CMS-14] was added and reacted for 3 hours. After completion of the reaction, the reaction solution was poured into 1.0 kg of diisopropyl ether to precipitate a pale yellow polymer. The supernatant was discarded by decantation. The remaining polymer was dissolved in 1.0 kg of methanol and poured into 1.0 kg of diisopropyl ether for reprecipitation. After thoroughly washing the remaining polymer with acetone, 1.0 g of N-nitrosophenylhydroxylamine ammonium salt [manufactured by Wako Pure Chemical Industries, Ltd., Q-1300] was added as a polymerization inhibitor, and the total amount was 300 g. The resulting polymer was dissolved in methanol to obtain a methanol solution of the target polymer (SP-12). As a result of measuring the solid content of this solution, it was 31%, and it was found that the polymer yield was 93 g and the polymer yield was 93%. As a result of measuring the molecular weight of the obtained polymer (SP-12) by gel permeation chromatography, it was found to be a polymer having a weight average molecular weight of 80000 (polystyrene conversion).

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to these Examples as well as an effect.

Reference example 1
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution was applied onto a polyethylene terephthalate film having a gelatin undercoat layer having a thickness of 0.10 mm and dried to a thickness of 2.0 μm to prepare a sample.
<Coating liquid>
Water-soluble polymer A (CP-1) 3.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Basic Blue 7 0.1 part by weight Methanol 50.0 parts by weight

The obtained sample was subjected to contact exposure for 30 seconds through a negative film using a high-pressure mercury lamp as a light source, adjusting the light amount so that the light amount was 20 mW / cm ² . After exposure, tap water whose temperature was adjusted to 25 ° C. was used for development for 20 seconds. As a result, unexposed portions were eluted and a clear image pattern was obtained.

Reference example 2
A sample was prepared in the same manner as in Reference Example 1 except that 3.0 parts by weight of pentaerythritol triacrylate was added as a polymerizable monomer having a polymerizable unsaturated bond group. This sample was exposed and developed in the same manner as in Reference Example 1 except that the exposure time was changed to 10 seconds. As a result, the unexposed area was eluted and a clear image pattern was obtained.

Comparative Example 1
A sample was prepared in the same manner as in Reference Example 1 except that the photopolymerization initiator (PI-1) was removed from the photosensitive composition of Reference Example 1. As a result of exposing and developing this sample in the same manner as in Reference Example 1, all of the sample was eluted, and no image pattern was obtained.

Comparative Example 2
A sample was prepared in the same manner as in Reference Example 2 except that the water-soluble polymer A (CP-1) in Reference Example 2 was changed to the following polymer (BP-1). As a result of exposing and developing this sample in the same manner as in Reference Example 2, all of the sample was eluted, and no image pattern was obtained.

Reference example 3
A photosensitive composition was prepared in the same manner as in Reference Example 2 except that the water-soluble polymer A (CP-1) in Reference Example 2 was changed to (CP-12). As a result of exposing and developing this sample in the same manner as in Reference Example 2, the unexposed portion was eluted and a clear image pattern was obtained.

Comparative Example 3
A sample was prepared in the same manner as in Reference Example 3 except that the water-soluble polymer A (CP-12) in Reference Example 3 was changed to the following polymer (BP-2). As a result of exposing and developing this sample in the same manner as in Reference Example 2, all of the sample was eluted, and no image pattern was obtained.

Reference example 4
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution was applied onto a polyethylene terephthalate film having a gelatin undercoat layer having a thickness of 0.10 mm and dried to a thickness of 2.0 μm to prepare a sample.
<Coating liquid>
Methanol solution of water-soluble polymer B (SP-9) (solid content 29% by weight)
10.3 parts by weight Photopolymerization initiator (PI-1) 0.5 part by weight Photopolymerization initiator (PI-2) 0.7 part by weight Basic Blue 7 0.1 part by weight Methanol 48.4 parts by weight

  As a result of exposing and developing the obtained sample in the same manner as in Reference Example 1, the unexposed portion was eluted and a clear image pattern was obtained.

Reference Example 5
A photosensitive composition was prepared in the same manner as in Reference Example 4 except that 1.0 part by weight of pentaerythritol triacrylate was added as a polymerizable monomer having a polymerizable unsaturated bond group. This sample was exposed in the same manner as in Reference Example 2. After the exposure, when developing was performed for 15 seconds using a developer having the following composition whose temperature was adjusted to 15 ° C., the unexposed area was eluted, and a clear image pattern was obtained.
<Developer>
Isopropyl alcohol 50 parts by weight Tap water 950 parts by weight

Comparative Example 4
A sample was prepared in the same manner as in Reference Example 4 except that the photopolymerization initiators (PI-1) and (PI-2) were removed from the photosensitive composition of Reference Example 4. As a result of exposing and developing this sample in the same manner as in Reference Example 1, all of the sample was eluted, and no image pattern was obtained.

Reference Example 6
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so that the dry thickness is 2.0 μm, and dried at 75 ° C. for 5 minutes, A lithographic printing plate was prepared.
<Coating liquid>
Water-soluble polymer A (CP-2) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-2) 1.0 part by weight Polymerizable monomer (pentaerythritol tri Acrylate)
3.0 parts by weight Sensitizer (S-1) 0.5 parts by weight Basic Blue 7 0.1 part by weight Methanol 50.0 parts by weight 1,4-dioxane 40.0 parts by weight

  The lithographic printing plate produced as described above was subjected to an exposure test using a blue semiconductor laser-mounted output machine; an image setter Cobalt8CTP (oscillation wavelength: 410 nm, output: 30 mW) manufactured by ESCHER GRAD. After exposure, tap water whose temperature was adjusted to 25 ° C. was used for development for 20 seconds. As a result, unexposed portions were eluted and a clear image pattern was obtained. Also, offset printing machine [Ryobi Co., Ltd .; Ryobi 560], ink [Dainippon Ink Chemical Co., Ltd .; FINE INK New Champion Ink (N)] and fountain solution [Niken Chemical Research Co., Ltd. ; Astromark III 1% aqueous solution] was used to evaluate the performance as a printing plate. As a result, up to 100,000 sheets of clear printed matter were obtained.

Reference Example 7
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so that the dry thickness is 2.0 μm, and dried at 75 ° C. for 5 minutes, A lithographic printing plate was prepared.
<Coating liquid>
Methanol solution of water-soluble polymer B (SP-12) (solid content 31% by weight)
41.9 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-2) 1.5 parts by weight Polymerizable monomer (T-1) 3.0 parts by weight Sensitizer ( S-1) 0.5 part by weight Basic Blue 7 0.1 part by weight Methanol 20.0 part by weight 1,4-dioxane 40.0 part by weight

  The lithographic printing plate produced as described above was exposed and developed in the same manner as in Reference Example 6. As a result, the unexposed area was eluted and a clear image pattern was obtained. In addition, a printing test was performed in the same manner as in Reference Example 6 and the performance as a printing plate was evaluated. As a result, a clear printed material was obtained up to 150,000 sheets.

  As is clear from the results of Reference Examples 6 and 7, the photosensitive material of the Reference Example has extremely high sensitivity to scanning exposure with blue semiconductor laser light, and is sharp and has high printing durability without performing post-exposure heat treatment. A relief image of force can be obtained.

Example 1
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so as to have a dry thickness of 2.0 μm, and dried at 80 ° C. for 10 minutes. Was made.
<Coating liquid>
Water-soluble polymer A (CP-12) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Cationic monomer (CM-14) 3.0 parts by weight Sensitizer (S-2) 0.5 parts by weight Methanol 20.0 parts by weight Water 80.0 parts by weight

The obtained sample was exposed as follows. That is, using an exposure machine [manufactured by Mitsubishi Paper Industries; Hishira Copy Printer] using a tungsten lamp as a light source, an interference filter of 580 nm is interposed, and the amount of light transmitted through the interference filter becomes 5 mW / cm ² . The amount of light was adjusted as described above, and exposure was performed for 30 seconds through a control wedge [manufactured by Fuji Photo Film Co., Ltd.] having a step wedge with a density difference of 0.15 intervals. After exposure, development was performed for 20 seconds using tap water whose temperature was adjusted to 25 ° C. In the step wedge pattern formed on the aluminum plate after development, the maximum number of steps remaining as an image was obtained as sensitivity. As a result, the number of steps was nine. The larger the step number, the higher the sensitivity.

Example 2
A sample was prepared in the same manner as in Example 1 except that the polymer of Example 1 was changed to the following structural formula (BP-3). As a result of the same exposure and development as in Example 1, the number of steps was 7.

Comparative Example 5
A sample was prepared in the same manner as in Example 1 except that the polymer of Example 1 was changed to (BP-3) and the cationic monomer (CM-14) was changed to the following structural formula (T-2). . As a result of the same exposure and development as in Example 1, all were eluted and an image pattern could not be obtained.

  From the results of Examples 1 and 2 and Comparative Example 5 described above, the photosensitive material of the present invention containing a polymer, a cationic monomer, and a photopolymerization initiator and further containing a sensitizer in the visible light region. It has been found that a sharp relief image can be obtained with extremely high sensitivity and without performing post-exposure heat treatment. In particular, when the water-soluble polymer A is used as the polymer, a photosensitive material with higher sensitivity can be provided.

Reference Examples 8-12
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so as to have a dry thickness of 2.0 μm, and dried at 80 ° C. for 10 minutes. Was made.
<Coating liquid>
Water-soluble polymer B (described in Table 1) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-2) 1.5 parts by weight Polymerizable monomer (T- 1) 3.0 parts by weight Sensitizer (S-3) 0.5 parts by weight Basic Blue 7 0.1 part by weight Methanol 60.0 parts by weight 1,4-dioxane 40.0 parts by weight

The obtained sample was exposed in the same manner as in Example 1, and then developed for 15 seconds using a developer having the following composition whose temperature was adjusted to 15 ° C. In the pattern of the step wedge formed on the aluminum plate after development, the maximum number of steps remaining as an image was determined as sensitivity. The results are summarized in Table 1.
<Developer>
n-Butyl Cellosolve 30 parts by weight Tap water 970 parts by weight

Comparative Example 6
Samples were prepared in the same manner except that the water-soluble polymer B of the photosensitive compositions of Reference Examples 8 to 12 was changed to the following polymer (BP-4). As a result of exposing and developing this sample in the same manner as in Reference Examples 8 to 12, the unexposed portion was not eluted at all, and a relief image could not be obtained.

  From the above results, the photosensitive material of the reference example containing the water-soluble polymer B and the photopolymerization initiator, and further containing a polymerizable monomer having a polymerizable unsaturated bond group, and a sensitizer was used in the visible light region. Thus, it was found that a sharp relief image can be obtained with extremely high sensitivity without performing post-exposure heat treatment.

Examples 3 to 5 and Reference Examples 13 and 14
A coating solution of a photosensitive composition having the following composition was prepared. Next, the coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so as to have a dry thickness of 2.0 μm, and dried at 75 ° C. for 5 minutes. Produced.
<Coating liquid>
Water-soluble polymer A (CP-6) 12.0 parts by weight Photopolymerization initiator (PI-2) 1.0 part by weight Polymerizable monomer (described in Table 2) 3.0 parts by weight Sensitizer (S-4 0.5 part by weight Basic Blue 7 0.1 part by weight Methanol 50.0 part by weight 1,4-dioxane 40.0 part by weight

The obtained sample was exposed as follows. That is, using a contact exposure machine [Mitsubishi Paper Co., Ltd .; Hishira Copy Printer] using a tungsten lamp as a light source, a light of 3 mW / cm ² and a wavelength of 780 nm or more is passed through a filter that blocks light of 780 nm or less. Light was allowed to pass through, and exposure was performed on this filter for 10 seconds through a control wedge (manufactured by Fuji Photo Film Co., Ltd.) with a density difference of 0.15 intervals. After exposure, development was performed for 20 seconds using tap water whose temperature was adjusted to 25 ° C. In the step wedge pattern formed on the aluminum plate after the development processing, the maximum step number remaining as an image was obtained as sensitivity. The results are summarized in Table 2.

  As apparent from the above results, the photosensitive materials containing the water-soluble polymer A, the polymerizable monomer, the photopolymerization initiator, and the sensitizer in Examples 3 to 5 and Reference Examples 13 and 14 A sharp relief image can be obtained with high sensitivity even in the outside light region without performing post-exposure heat treatment. In particular, when the cationic monomer of the present invention having two or more polymerizable unsaturated bonding groups in the molecule is used as the polymerizable monomer, a highly sensitive photosensitive composition can be obtained.

Reference Examples 15-19
A coating solution of a photosensitive composition having the following composition was prepared. The coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so that the dry thickness is 2.0 μm, and dried at 75 ° C. for 5 minutes to prepare a sample. did.
<Coating liquid>
Water-soluble polymer B (described in Table 3) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-2) 1.5 parts by weight Polymerizable monomer (T- 5) 3.0 parts by weight Sensitizer (S-5) 0.5 parts by weight Basic Blue 7 0.1 part by weight Methanol 60.0 parts by weight 1,3-dioxolane 40.0 parts by weight

Comparative Example 7
Samples were prepared in the same manner as in the above Example, except that the water-soluble polymer B of Reference Examples 15 to 19 was changed to the following structural formula (BP-5).

  The obtained photosensitive material was exposed in the same manner as in Example 3, and then developed for 20 seconds using tap water whose temperature was adjusted to 25 ° C. within 1 minute or 3 hours. In the step wedge pattern formed on the aluminum plate after the development processing, the maximum step number remaining as an image was obtained as sensitivity. The results are summarized in Table 3.

As is clear from the above results, the photosensitive materials containing both the water-soluble polymer B, the photopolymerization initiator, the polymerizable monomer having a polymerizable unsaturated bond group, and the sensitizer in Reference Examples 15 to 19, Even in the near-infrared region, the sensitivity is extremely high, and a sharp relief image can be obtained without performing post-exposure heat treatment. Further, it can be seen that the reference examples 15 to 19 have almost no latent image regression compared to the comparative example 7.

Example 6
The coating liquid of the following photosensitive composition was produced. The coating liquid is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so as to have a dry thickness of 2.0 μm, and dried at 75 ° C. for 5 minutes. Was made.
<Coating liquid>
Water-soluble polymer A (CP-2) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-3) 1.0 part by weight Cationic monomer (CM-14) ) 3.0 parts by weight Sensitizer (S-4) 0.5 parts by weight Basic Blue 7 0.1 part by weight Methanol 50.0 parts by weight 1,4-dioxane 40.0 parts by weight

The lithographic printing plate produced as described above is wound around the outer surface of a cylindrical drum, and the drum rotation speed is 300 to 2000 rpm using a semiconductor laser having an output of 1.2 W (variable 0 to 1.2 W) that emits light at 830 nm. The exposure test was conducted with various laser irradiation energy and drum rotation speed. The spot diameter of the laser beam at this time was adjusted to 10 μm. Within 1 minute or 1 hour after exposure, development was performed for 30 seconds using tap water whose temperature was adjusted to 25 ° C. The minimum exposure energy for clearly forming a 10 μm line on an aluminum plate is 120 mJ / cm ² when developed within 1 minute after exposure, and 150 mJ / cm when developed after 1 hour after exposure. ² .

  The above lithographic printing plate is used as an offset printing machine [Ryobi Co., Ltd .; Ryobi 560], ink [Dainippon Ink Chemical Co., Ltd .; FINE INK New Champion Ink (N)] and dampening water [Niken Corporation]. As a result of evaluating printing durability using a 1% aqueous solution of Astro Mark III manufactured by Chemical Laboratory, the print image quality did not change even after printing 150,000 sheets.

Example 7
A coating solution of a photosensitive composition having the same composition as in Example 6 was applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so that the dry thickness was 2.5 μm. Drying was performed at 75 ° C. for 7 minutes to prepare a lithographic printing plate. The obtained lithographic printing plate was wound around the outer surface of a cylindrical drum, and exposed with an exposure energy of 150 mJ / cm ² using a semiconductor laser emitting light at 830 nm. After the exposure, without being developed, it was directly attached to an offset printing machine [Ryobi Co., Ltd .; Ryobi 560], and printing was performed using the same ink and fountain solution as in Example 25. Within 60 sheets from the start of printing, the non-image area that was an unexposed area was removed, and 100,000 high-quality prints without stains on the non-image area were obtained.

Example 8
A coating solution of the photosensitive composition having the same composition as in Example 6 was dried on an aluminum plate subjected to graining treatment having a thickness of 0.24 mm, anodizing treatment, and silicate treatment with an aqueous sodium silicate solution. It was applied to 5 μm and dried at 75 ° C. for 7 minutes to prepare a lithographic printing plate. The obtained lithographic printing plate was exposed in the same manner as in Example 7, and a printing test was performed as it was. Within 10 sheets from the start of printing, the non-image area which is an unexposed area was removed, and 100,000 high-quality prints with no stain on the non-image area were obtained.

  As is clear from the results of Examples 6, 7 and 8 above, the photosensitive material of the present invention containing the water-soluble polymer A, the cationic monomer, the photopolymerization initiator, and the sensitizer in combination with the near-infrared laser. With extremely high sensitivity to scanning exposure by light, there is almost no latent image regression, and a sharp and high printing durability relief image can be obtained without performing post-exposure heat treatment. Further, after exposure, without performing development processing, a lithographic printing plate can be mounted on a printing machine for printing, and a high-quality printed matter having no stain on the non-image area can be obtained. Further, when an aluminum plate subjected to silicate treatment is used, the non-image area is particularly excellent in removability, and it is possible to reduce damaged paper immediately after the start of printing.

Reference Example 20
An undercoat coating solution having the following composition was prepared. The undercoat coating solution is applied onto a 0.275 mm thick polyethylene terephthalate film subjected to corona treatment so that the dry thickness is 0.3 μm, and dried at 70 ° C. for 1 minute. Was made.
<Undercoating liquid>
Resin emulsion having hydrolyzable silyl group; Sanmor SW-131
[Sanyo Chemical Industries, Ltd.] (solid content 31% by weight) 100 parts by weight Self-emulsifying isocyanate; Duranate WB40-80
[Asahi Kasei Kogyo Co., Ltd.] (solid content 80% by weight) 4 parts by weight Water 900 parts by weight Surfactant 2 parts by weight

A film base having a hydrophilic layer, coated with a hydrophilic polymer solution having the following composition so that the dry thickness is 0.3 μm and dried at 80 ° C. for 2 hours on the undercoated film base produced as described above. Was made.
<Hydrophilic polymer solution>
Hydrophilic polymer (Structural Formula 39 below) 25 parts by weight Surfactant 1 part by weight Water 800 parts by weight

A coating solution of the photosensitive composition having the same composition as in Reference Example 19 was applied to the film base having the hydrophilic layer prepared as described above so that the dry thickness was 2.5 μm, and the temperature was 75 ° C. for 5 minutes. Drying was performed to prepare a lithographic printing plate. The obtained lithographic printing plate was wound around the outer surface of a cylindrical drum and exposed with an exposure energy of 140 mJ / cm ² using a semiconductor laser emitting light at 830 nm. After the exposure, the image was directly attached to an offset printer [manufactured by Ryobi Co., Ltd .; Ryobi 560] without performing development, and printing was performed using the same ink and fountain solution as in Example 6. Within 20 sheets from the start of printing, the non-image area, which is an unexposed area, was removed, and 20,000 high-quality prints having no stain on the non-image area were obtained.

Reference Example 21
A coating solution of a photosensitive composition having the following composition was prepared. The coating solution is applied on a grained and anodized aluminum plate having a thickness of 0.24 mm so as to have a dry thickness of 2.5 μm, and dried at 75 ° C. for 7 minutes. Was made.
<Coating liquid>
Water-soluble polymer B (SP-12) 12.0 parts by weight Photopolymerization initiator (PI-1) 1.0 part by weight Photopolymerization initiator (PI-4) 1.0 part by weight Polymerizable monomer (T-6) ) 3.0 parts by weight Sensitizer (S-6) 0.5 parts by weight Methanol 60.0 parts by weight 1,4-dioxane 40.0 parts by weight

The lithographic printing plate produced as described above was exposed in the same manner as in Example 6, and developed within 20 minutes using tap water adjusted to 25 ° C. within 1 minute or 3 hours. It was. The minimum exposure energy for clearly forming a 10 μm line on an aluminum plate is 100 mJ / cm ² when developed within 1 minute after exposure, and 110 mJ / cm when developed after 3 hours after exposure. ² .

  The lithographic printing plate was printed in the same manner as in Example 6 and the printing durability was evaluated. As a result, the print image quality did not change even after printing 150,000 sheets.

Reference Example 22
The same lithographic printing plate as in Reference Example 21 was produced. The obtained lithographic printing plate was wound around the outer surface of a cylindrical drum and exposed with an exposure energy of 120 mJ / cm ² using a semiconductor laser emitting light at 830 nm. After the exposure, the image was directly attached to an offset printer [manufactured by Ryobi Co., Ltd .; Ryobi 560] without performing development, and printing was performed using the same ink and fountain solution as in Example 6. Within 40 sheets from the start of printing, the non-image area, which is an unexposed area, was removed, and 150,000 sheets of high-quality prints with no stain on the non-image area were obtained.

Reference Example 23
A coating solution of the photosensitive composition having the same composition as that of Reference Example 21 was dried on an aluminum plate having a thickness of 0.24 mm, subjected to graining treatment, anodizing treatment, and silicate treatment with a sodium silicate aqueous solution. It was applied to 5 μm and dried at 75 ° C. for 7 minutes to prepare a lithographic printing plate. The obtained lithographic printing plate was exposed in the same manner as in Reference Example 22, and a printing test was performed as it was. Within 10 sheets from the start of printing, the non-image area, which was an unexposed area, was removed, and 150,000 sheets of high-quality printed material without smudges on the non-image area were obtained.

  As apparent from the results of Reference Examples 20, 21, 22, and 23, the water-soluble polymer B, the photopolymerization initiator, the polymerizable monomer having a polymerizable unsaturated bond group in the molecule, and the sensitizer are combined. The photosensitive material of the present invention includes a very high sensitivity to scanning exposure with near-infrared laser light, almost no latent image regression, and a sharp and high printing durability relief image without post-exposure heat treatment. Obtainable. Moreover, after exposure, without performing development processing, a lithographic printing plate can be mounted on a printing machine and printed, and a high-quality printed matter having non-image areas can be obtained. Further, when an aluminum plate subjected to silicate treatment is used, the non-image area is particularly excellent in removability, and it is possible to reduce damaged paper immediately after the start of printing.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive composition which can obtain a sharp and firm relief image by water development can be provided even if it does not perform a heat treatment after exposure. Furthermore, since the photosensitive wavelength range can be selected widely, a light source including various lasers can be used, and a lithographic printing plate excellent in printing durability can be obtained. Furthermore, a photosensitive composition and a lithographic printing plate free from latent image regression are obtained. Further, a photosensitive composition and a lithographic printing plate that do not require an overlayer can be obtained. Furthermore, it is possible to provide a lithographic printing plate which can be printed as it is by mounting the lithographic printing plate on a printing machine without performing development processing.

Claims (1)

Characterized in that the polymerizable unsaturated bond group possess two or more in a molecule, a cationic monomer which have a quaternary ammonium group as a cationic group, containing a polymer, and a photopolymerization initiator or photoacid generator A photosensitive composition.