JP4648695B2 - Photosensitive composition and photosensitive lithographic printing plate material - Google Patents

Description

  The present invention relates to a photosensitive composition, and further to a photosensitive lithographic printing plate material using the same. More specifically, the present invention relates to a photosensitive composition and a photosensitive lithographic printing plate material capable of forming an image using a scanning exposure apparatus such as a laser. Furthermore, it is related with the photosensitive composition suitable for formation of the resist for printed wiring board preparation, a color filter, a fluorescent substance pattern, etc.

  In the photosensitive composition, the molecular structure undergoes a chemical change by a photoreaction, and as a result, a physical phenomenon (physical property) changes. This chemical change by the action of light includes cross-linking, polymerization, decomposition, depolymerization, functional group conversion, etc., and there are various such as solubility, adhesiveness, refractive index, substance permeability and phase change. Such photosensitive compositions have been put into practical use in a wide range of fields such as printing plates, resists, paints, coating agents, and color filters. Furthermore, it has been utilized and developed in the field of photoresist using photoengraving technology (photolithography). Photoresists utilize changes in solubility due to photoreactions, and more precise material design is required due to high resolution requirements.

  A widely used type of lithographic printing plate has a photosensitive coating applied to an aluminum base support. In this coating film, the exposed coating film portion is cured, and the unexposed coating film portion is eluted by the development process. Such a plate is called a negative printing plate. Lithographic printing utilizes the oleophilic and hydrophilic surface properties of the pattern formed on the surface of the printing plate and the background, and when supplying ink and dampening water simultaneously to the printing plate on the printing press in lithographic printing, It utilizes the selective transfer of ink onto a pattern having an oleophilic surface. The ink transferred onto the pattern is then transferred to an intermediate body called a blanket, and further transferred to a printing paper for printing.

  Many studies have been made on a photosensitive composition that forms a relief image by utilizing the above-described change in solubility due to a photoreaction, and has been put into practical use. For example, JP-B-49-34041 (Patent Document 1), JP-A-6-105353 (Patent Document 2) and the like mainly comprise a polymer having an ethylenically unsaturated bond in the side chain, a crosslinking agent and a photopolymerization initiator. A photosensitive composition is disclosed. These have photosensitivity to light having a short wavelength centering on an ultraviolet region of 400 nm or less.

  On the other hand, in recent years, with the advancement of image forming technology, a photosensitive material exhibiting high sensitivity to visible light has been demanded. For example, research on photosensitive materials 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, it has become possible to easily use near-infrared laser light sources of 700 to 1300 nm, and photosensitive materials and photosensitive lithographic printing plates corresponding to the laser beams have attracted attention. .

  As a photopolymerizable composition having photosensitivity to visible light to near infrared light, JP-A-9-134007 (Patent Document 3) discloses a radically polymerizable compound having an ethylenically unsaturated bond and 400 to 500 nm. Lithographic printing plate materials containing a photosensitizing dye having an absorption peak and a polymerization initiator are disclosed in JP-A-62-143044, JP-A-62-1050242, and JP-A-5-5988 (Patent Document 4). ), No. 5-194619 (Patent Document 5), No. 5-97069, No. 2000-98603 (Patent Document 6), etc. disclose a combination of an organic boron anion and a dye. JP-A-4-31863 (Patent Document 7) and JP-A-6-43633 disclose a combination of a dye and an S-triazine compound, and JP-A-7-20629 and JP-A-7-27102. JP-A-11-212252 and JP-A-11-231535 disclose a combination of a resol resin, a novolak resin, an infrared absorber and a photoacid generator. A combination of near infrared sensitizing dyes is disclosed.

  However, a polymerizable composition using a photopolymerization initiator or photoacid generator as described above is difficult to impart sufficiently high photosensitivity in the visible light to near-infrared region, and particularly various laser beams were used. Photosensitivity was insufficient for application to scanning exposure.

  In addition, the polymerizable composition as described above has a problem that the latent image retreats after exposure. That is, an originally exposed portion forms an image after development, but there is a problem of so-called latent image regression that an image is not sufficiently formed with the passage of time from exposure to development processing. This phenomenon can occur between several tens of minutes to several hours after exposure depending on conditions such as temperature and humidity and exposure amount.

  In addition, the above-described photosensitive composition has a problem that it is difficult to ensure stability such as sensitivity and long-term storage stability. For this reason, an oxygen barrier property is enhanced on the upper part of the photosensitive layer and surface scratches are prevented. It is common practice to provide an overlayer made of the desired polyvinyl alcohol or the like. Due to the presence of such an over layer, there is a problem of deterioration in image quality due to light scattering during laser exposure, and when developing, a pre-water washing step for removing the over layer is required prior to alkali development. In addition, there is a problem in that a process for applying an overlayer is necessary after the photosensitive layer is applied.

In addition, the polymerization with the photopolymerization initiator or the photoacid generator is often insufficient only by exposure, and it is necessary to heat and complete the polymerization after the exposure or the development process. In particular, in the case of a photosensitive lithographic printing plate material imparted with photosensitivity in the visible light to infrared light wavelength range, the heat treatment was an important plate making process. However, the heat treatment not only lowers the production efficiency but also includes factors that make the quality unstable. For example, it is difficult to keep the difference in solubility between the exposed area and the unexposed area constant. If sufficient heating is not performed, the developer will dissolve up to the exposed area, or if the heating temperature is too high. There is a problem that the unexposed portion is partially insolubilized and development is not sufficiently performed.
Japanese Patent Publication No.49-34041 Japanese Examined Patent Publication No. 6-105353 JP-A-9-134007 JP-A-5-5988 JP-A-5-194619 JP 2000-98603 A JP-A-4-31863

  Accordingly, an object of the present invention is to provide a photosensitive composition with high sensitivity. In particular, it is to provide a photosensitive composition and a photosensitive lithographic printing plate having sufficiently high sensitivity from visible light to infrared light. Another object of the present invention is to provide a photosensitive composition capable of scanning exposure and a photosensitive lithographic printing plate that does not require heat treatment. A further object of the present invention is to provide a photosensitive composition and a photosensitive lithographic printing plate that do not require an overcoat layer. Still another object of the present invention is to provide a photosensitive composition and a photosensitive lithographic printing plate free from latent image regression.

The above object of the present invention has been basically achieved by using the following photosensitive composition.
1) A polymer having a phenyl group substituted with a vinyl group in the side chain , wherein the phenyl group is bonded to the main chain via a linking group (provided that the linking group includes a heterocyclic ring in the side chain) (Not including polymers and polyurethane resins having phenyl groups substituted with vinyl groups via), monomers having two or more phenyl groups substituted with vinyl groups in the molecule, organoboron salts and trihaloalkyls as photoradical generators A photosensitive composition comprising at least one selected from substituted compounds, and a sensitizer that absorbs in the wavelength region of visible light to infrared light and sensitizes the photoradical generator.
In the polymer and the monomer, the phenyl group may be substituted with a substitutable group or atom other than a vinyl group, and the vinyl group may be substituted.
The photosensitive composition according to 1) is for 2) run査露light.
3 ) The photosensitive composition as described in 1) above, which is for a near infrared laser of 750 to 1100 nm.
4 ) The photosensitive composition as described in 1) above, which is for a blue semiconductor laser having a wavelength of 400 to 430 nm.
5 ) A photosensitive lithographic printing plate material using the photosensitive composition according to any one of 1) to 4 ) above.

  According to the present invention, it is possible to obtain an image that is highly sensitive as a photosensitive material and can withstand development and printing without performing heat treatment after exposure. Furthermore, since a photosensitive wavelength range can be selected widely, a light source including various lasers can be used, and a lithographic printing plate having excellent printing durability can be obtained. Furthermore, a photosensitive material and a lithographic printing plate free from latent image regression can be obtained. Further, a photosensitive material and a lithographic printing plate that do not require an overlayer can be obtained.

  Hereinafter, the present invention will be described in detail. The polymer having a phenyl group with a vinyl group substituted on the side chain used in the present invention is one in which the phenyl group is bonded to the main chain directly or via a linking group, and the linking group is not particularly limited. , Any group, atom, or a combination thereof. However, the heterocyclic group is not included in the linking group. The phenyl group may be substituted with a substitutable group or atom, and the vinyl group is a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, It may be substituted with an aryl group, an alkoxy group, an aryloxy group or the like. More specifically, the polymer having a phenyl group in which a vinyl group is substituted on the side chain described above has a group represented by the following chemical formula 1 in the side chain.

In the formula, Z ₁ represents a linking group, and R ₁ , R ₂ , and R ₃ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, and an aryl group. A group, an alkoxy group, an aryloxy group, and the like, and these groups may be substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, or the like. R ₄ represents a substitutable group or atom. n represents 0 or 1, m ₁ represents an integer of 0 to 4, and k ₁ represents an integer of ₁ to 4.

The chemical formula 1 will be described in more detail. As the linking group for Z ₁ , an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an arylene group, —N (R ₅ ) —, —C (O) —O—, —C (R ₆ ) ═N—, Examples include —C (O) —, a sulfonyl group, and a group represented by the following chemical formula 2 alone or in combination of two or more. Here, R ₅ and R ₆ represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

  Although the example of group represented by Chemical formula 1 is shown below, it is not limited to these examples.

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

  The polymer having a group as shown in the above example is preferably soluble in an alkaline aqueous solution, and therefore a polymer containing a carboxyl group-containing monomer as a copolymerization component is particularly preferable. In this case, as a ratio of the group represented by Chemical Formula 1 in the copolymer composition, the group represented by Chemical Formula 1 in the total composition of 100% by weight is preferably 1% by weight to 95% by weight, If the ratio is less than this, the introduction effect may not be recognized. In addition, when it is contained in an amount of 95% by weight or more, the copolymer may not be dissolved in the alkaline aqueous solution. Further, the ratio of the carboxyl group-containing monomer in the copolymer is preferably 5% by weight or more and 99% by weight or less, and if the ratio is less than this, the copolymer may not be dissolved in the alkaline aqueous solution.

  Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, acrylic acid 2-carboxyethyl ester, methacrylic acid 2-carboxyethyl ester, crotonic acid, maleic acid, fumaric acid, maleic acid monoalkyl ester, and fumaric acid monoalkyl. Examples include esters, 4-carboxystyrene and the like.

  In addition to the monomer having a carboxyl group, other monomer components may be introduced into the copolymer to be synthesized and used as a multi-component copolymer. In such cases, monomers that can be incorporated into the copolymer include styrene, 4-methylstyrene, 4-hydroxystyrene, 4-acetoxystyrene, 4-carboxystyrene, 4-aminostyrene, chloromethylstyrene, and 4-methoxystyrene. Styrene derivatives such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, methacrylic acid alkyl esters such as dodecyl methacrylate, phenyl methacrylate, benzyl methacrylate, etc. Methacrylic acid aryl ester or alkyl aryl ester, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methoxydiethylene glycol monomethacrylate Asteryl, methacrylic acid methoxypolyethylene glycol monoester, methacrylic acid ester having alkyleneoxy group such as methacrylic acid polypropylene glycol monoester, amino group-containing methacrylic acid ester such as 2-dimethylaminoethyl methacrylate and 2-diethylaminoethyl methacrylate Or the same examples as the corresponding methacrylic acid esters as acrylic esters, or vinylphosphonic acid as a monomer having a phosphoric acid group, amino group-containing monomers such as allylamine and diallylamine, or vinylsulfonic acid And salts thereof, allylsulfonic acid and salts thereof, methallylsulfonic acid and salts thereof, styrenesulfonic acid and salts thereof, 2-acrylamido-2-methylpropanesulfonic acid and Monomers having a sulfonic acid group such as a salt of, monomers having a nitrogen-containing heterocycle such as 4-vinylpyridine, 2-vinylpyridine, N-vinylimidazole, N-vinylcarbazole, or monomers having a quaternary ammonium base 4-vinylbenzyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, quaternized product of dimethylaminopropylacrylamide with methyl chloride, quaternized product of N-vinylimidazole with methyl chloride, 4-vinyl Benzylpyridinium chloride, etc., or acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, dimethylacrylamide, diethylamine Acrylamide or methacrylamide derivatives such as chloramide, N-isopropylacrylamide, diacetone acrylamide, N-methylol acrylamide, N-methoxyethyl acrylamide, 4-hydroxyphenyl acrylamide, acrylonitrile, methacrylonitrile, phenylmaleimide, hydroxyphenylmaleimide, Vinyl acetates such as vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl benzoate, vinyl ethers such as methyl vinyl ether, butyl vinyl ether, others, N-vinyl pyrrolidone, acryloyl morpholine, tetrahydrofluor Furyl methacrylate, vinyl chloride, vinylidene chloride, allyl alcohol, vinyl trimethoxysilane It may be used glycidyl methacrylate and various monomers as arbitrary copolymerization monomers. The proportion of these monomers in the copolymer may be any as long as the preferred proportion of the group and carboxyl group-containing monomer represented by Chemical Formula 1 in the copolymer composition described above is maintained. It can be introduced at a rate.

  There is a preferred range for the molecular weight of the polymer as described above, and 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.

  Examples of the polymer having a group represented by Chemical Formula 1 according to the present invention are shown below. In the formula, the number represents the weight percent of each repeating unit in the copolymer total composition of 100 weight percent.

  The present invention contains, together with the above-described polymer, a photoradical generator and a sensitizer that absorbs in the wavelength range of visible light to infrared light and sensitizes the photoradical generator. As the photo radical generator used in the present invention, any compound can be used as long as it is a compound capable of generating radicals by light irradiation. For example, organic boron salts, trihaloalkyl-substituted compounds (for example, s-triazine compounds and oxadiazole derivatives, trihaloalkylsulfonyl compounds as trihaloalkyl-substituted nitrogen-containing heterocyclic compounds), hexaarylbisimidazoles, titanocene compounds, ketoxime compounds , Thio compounds, organic peroxides and the like. Among these photoradical generators, organic boron salts and trihaloalkyl-substituted compounds are particularly preferably used. More preferably, an organic boron salt and a trihaloalkyl-substituted compound are used in combination.

  An organic boron anion constituting the organic boron salt is represented by the following chemical formula 8.

In the formula, each of R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ may be the same or different, and represents an alkyl group, aryl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group or heterocyclic group. To express. Of these, it is particularly preferred that one of R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ is an alkyl group and the other substituent is an aryl group.

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

  One preferred embodiment according to the present invention is a photosensitive composition containing both an organic boron salt and a dye for sensitizing the organic boron salt. In this case, the organic boron salt is sensitive to a wavelength region from visible light to infrared light. The light is not sensitive to light in such a wavelength range until the addition of a sensitizing dye.

  The organic boron salt used in the present invention is a salt containing an organic boron anion represented by the chemical formula 8 shown above, and alkali metal ions and onium compounds are preferably used as cations forming the salt. Particularly preferable examples of the onium salt with an organic boron anion include ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and phosphonium salts such as triarylalkylphosphonium salts. Examples of particularly preferred organic boron salts are shown below.

  In the present invention, other preferred photoradical generators include trihaloalkyl-substituted compounds. Specifically, the trihaloalkyl-substituted compound is a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. As a preferable example, the trihaloalkyl group is a nitrogen-containing complex. Examples of the compound bonded to the ring group include s-triazine derivatives and oxadiazole derivatives, or trihaloalkylsulfonyl compounds in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocycle via a sulfonyl group. .

  Particularly preferred examples of trihaloalkyl-substituted nitrogen-containing heterocyclic compounds and trihaloalkylsulfonyl compounds are shown in Chemical Formulas 11 and 12.

  Another photo radical generator used in the present invention is an organic peroxide. Examples thereof include cumene hydroperoxide, tertiary butyl hydroperoxide, dichloroperoxide, ditertiary butyl peroxide, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, and the following chemical formula 13 and the like.

  The content of the photo radical generator as described above is preferably included in the range of 1 to 100% by weight with respect to the polymer having a phenyl group substituted with a vinyl group in the side chain, and more preferably 1 to 40%. It is preferably contained in the range of wt%.

  The photosensitive composition of the present invention has absorption in the wavelength region from visible light to infrared light so as to be compatible with various light sources from visible light to infrared light, and sensitizes the above-mentioned photo radical generator. Contains a sensitizer. 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, and further described in European Patent No. 0,568,993, US Pat. Nos. 4,508,811, and 5,227,227. Compounds can also be used.

  Specific examples of the sensitizing dye having absorption in visible light (400 to 700 nm) are shown below, but the present invention is not limited thereto.

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. Specific examples of the sensitizing dye used for sensitizing to the near infrared are shown below.

A sensitizing dye in which the counter anion of the sensitizing dye exemplified above is substituted with the organic boron anion described above can also be used. The content of the sensitizing dye is suitably about 3 to 300 mg per 1 m ^{2 of the} photosensitive composition. Preferably it is 10-200 mg / m < ² >.

  In the present invention, as another preferable element constituting the photosensitive composition, a polymerizable compound having two or more polymerizable double bonds in the molecule (monomer or oligomer and having a molecular weight of 10,000 or less, preferably 5000 or less) is used. Can be mentioned. Examples of preferred polymerizable compounds include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trisacryloyloxyethyl isocyanurate, tripropylene glycol diacrylate. Examples thereof include polyfunctional acrylic monomers such as acrylate, ethylene glycol glycerol triacrylate, glycerol epoxy triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate.

  Alternatively, an oligomer having radical polymerizability is preferably used in place of the above-described polymerizable compound, and polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, etc. as various oligomers into which acryloyl group or methacryloyl group is introduced Are used in the same manner, but these can also be treated as polymerizable compounds.

  There is a preferred range for the ratio of the polymerizable compound as described above to the polymer having a phenyl group substituted with a vinyl group in the side chain, and the polymerizable compound is 0.01 part by weight with respect to 1 part by weight of the polymer. To 10 parts by weight, and more preferably 0.05 parts to 1 part by weight.

  When utilizing conventional radical photopolymerization, it is necessary to provide a resin such as polyvinyl alcohol having an oxygen barrier property as an overlayer on the surface of the photosensitive layer. . Further, in order to promote or complete the polymerization after exposure, it was necessary to perform a heat treatment at a temperature of about 100 ° C. for about several minutes.

  On the other hand, when a polymer having a phenyl group substituted with a vinyl group in the side chain is used, a sufficiently photocuring system is provided without providing an overlayer as described above, and heating is performed after exposure. It is characterized by the fact that it does not need to be treated, and is characterized in that a highly sensitive photosensitive composition can be obtained by using a combination of a photoradical generator and a sensitizing dye. Further, the photosensitive composition of the present invention is characterized by extremely low latent image regression.

  Next, a photosensitive composition containing a monomer having two or more phenyl groups substituted with vinyl groups in the molecule, a binder resin, and a photo radical generator, which is another embodiment of the present invention, will be described. However, the binder resin does not include a polymer having a phenyl group substituted with a vinyl group via a linking group containing a heterocyclic ring in the side chain.

  When a monomer having two or more phenyl groups substituted with vinyl groups in the molecule (hereinafter referred to as the monomer of the present invention) is used, crosslinking is effectively performed by recombination of styryl radicals generated by the generated radicals. Therefore, a negative photosensitive material that is highly sensitive and does not require heat treatment can be produced. The monomer of the present invention is typically represented by the following general formula.

In the formula, Z ₂ represents a linking group, and R ₂₁ , R ₂₂ and R ₂₃ are a hydrogen atom, a halogen atom, a carboxy group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, and an aryl group. An alkoxy group, an aryloxy group, and the like, and these groups may be substituted with an alkyl group, an amino group, an aryl group, an alkenyl group, a carboxy group, a sulfo group, a hydroxy group, or the like. R ₂₄ represents a substitutable group or atom. m ₂ represents an integer of 0 to 4, and k ₂ represents an integer of 2 or more.

The formula 22 will be described in more detail. As the linking group for Z ₂ , an oxygen atom, a sulfur atom, an alkylene group, an alkenylene group, an arylene group, —N (R ₅ ) —, —C (O) —O—, —C (R ₆ ) ═N—, Examples include —C (O) —, a sulfonyl group, a heterocyclic group, or a group in which two or more are combined. Here, R ₅ and R ₆ represent a hydrogen atom, an alkyl group, an aryl group, or the like. Furthermore, the above-described linking group may have a substituent such as an alkyl group, an aryl group, or a halogen atom.

  Examples of the heterocyclic group include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thiatriazole 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 ring, quinoxaline ring, etc. A nitrogen-containing heterocyclic ring, a furan ring, a thiophene ring and the like, and a substituent may be bonded to these.

Among the compounds represented by the above formula 22, there are preferred compounds. That is, R ₂₁ and R ₂₂ are hydrogen atoms, R ₂₃ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (methyl group, ethyl group, etc.), and k ₂ is preferably a compound having 2-10. Specific examples of the compound represented by Chemical Formula 22 are shown below, but the invention is not limited to these examples.

  The addition amount of the monomer of the present invention described above is preferably included 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 binder resin. It is particularly preferred that it be included.

  The binder resin used together with the monomer of the present invention is not particularly limited, and various known binder resins can be used. Specifically, styrene derivatives such as styrene, 4-methylstyrene, 4-hydroxystyrene, 4-monoacetoxystyrene, 4-carboxystyrene, 4-aminostyrene, chloromethylstyrene, 4-methoxystyrene, methyl methacrylate, Methacrylic acid alkyl esters such as ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, etc., aryl methacrylate or alkyl aryl esters such as phenyl methacrylate, benzyl methacrylate, etc. , 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methoxydiethylene glycol monoester methacrylate, methoxypolyethylene glycol monomethacrylate Steal, methacrylic acid esters having an alkyleneoxy group such as polypropylene glycol monoester methacrylate, amino group-containing methacrylic acid esters such as 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, or acrylic acid esters Examples similar to the corresponding methacrylic acid esters, or vinylphosphonic acid as a monomer having a phosphoric acid group, or amino group-containing monomers such as allylamine and diallylamine, or vinylsulfonic acid and salts thereof, allylsulfonic acid and Monomers having sulfonic acid groups such as salts thereof, methallylsulfonic acid and salts thereof, styrenesulfonic acid and salts thereof, 2-acrylamido-2-methylpropanesulfonic acid and salts thereof, 4-vinylpyridy 4-vinylbenzyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride as monomers having nitrogen-containing heterocycles such as ethylene, 2-vinylpyridine, N-vinylimidazole and N-vinylcarbazole, or monomers having a quaternary ammonium base , Methacryloyloxyethyltrimethylammonium chloride, quaternized product of dimethylaminopropylacrylamide with methyl chloride, quaternized product of N-vinylimidazole with methyl chloride, 4-vinylbenzylpyridinium chloride, or acrylonitrile, methacrylonitrile, acrylamide, Methacrylamide, dimethylacrylamide, diethylacrylamide, N-isopropylacrylamide, diacetone Acrylamide or methacrylamide derivatives such as chloramide, N-methylolacrylamide, N-methoxyethylacrylamide, 4-hydroxyphenylacrylamide, acrylonitrile, methacrylonitrile, phenylmaleimide, hydroxyphenylmaleimide, vinyl acetate, vinyl chloroacetate, propionic acid Vinyl esters such as vinyl, vinyl butyrate, vinyl stearate, vinyl benzoate, and vinyl ethers such as methyl vinyl ether and butyl vinyl ether, N-vinylpyrrolidone, acryloylmorpholine, tetrahydrofurfuryl methacrylate, vinyl chloride, vinylidene chloride, Various monomers such as allyl alcohol, vinyltrimethoxysilane, glycidyl methacrylate, etc. A copolymer containing any combination of al can be used as a binder.

  Furthermore, the binder resin is preferably soluble in an alkaline aqueous solution, and for that purpose, a polymer containing a carboxyl group-containing monomer as a copolymerization component is particularly preferred. In this case, the proportion of the carboxyl group-containing monomer in the copolymer composition is preferably 5% by weight or more and 99% by weight or less in the total composition of 100% by weight, and more preferably 10 to 70% by weight. It is preferable to do this.

  Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, acrylic acid 2-carboxyethyl ester, methacrylic acid 2-carboxyethyl ester, crotonic acid, maleic acid, fumaric acid, maleic acid monoalkyl ester, and fumaric acid monoalkyl. Examples include esters, 4-carboxystyrene and the like.

  Examples of binder resins other than the above examples include polymers having a phenolic hydroxyl group, and polyvinyl phenol, phenol resin, polyhydroxybenzal, and the like can also be used.

  Among the binder resins used together with the monomer of the present invention, a polymer having a phenyl group in which a vinyl group is substituted on the side chain described above is particularly preferable. By using the monomer of the present invention and a polymer having a phenyl group substituted with a vinyl group in the side chain, a relief image with higher sensitivity and higher printing durability can be obtained without heat treatment. Furthermore, latent image regression is greatly improved.

  As the photoradical generator used together with the monomer and binder resin of the present invention, the above-mentioned photoradical generator is used. Preferred are organic boron salts and trihaloalkyl-substituted compounds, and the compounds as described above are used.

  Similarly, by using the above-described sensitizing dye in combination, a photosensitive composition having a high sensitivity to wavelengths in the visible light to near infrared light region can be obtained.

  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 styryl groups and improving 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.

  In addition, as an element constituting the photosensitive composition, various fine dyes and pigments are added for the purpose of enhancing the visibility of the image, and inorganic fine particles or organic fine particles are added for the purpose of preventing blocking of the photosensitive composition. The addition is also preferably performed.

  Regarding the thickness of the photosensitive layer itself when used as a lithographic printing plate material, it is preferably formed on the support with a dry thickness in the range of 0.5 to 10 microns, and more preferably in the range of 1 to 5 microns. Is extremely preferable in order to greatly improve printing durability. The photosensitive layer is prepared by mixing a solution containing the above three elements, and is coated on a support and dried using various known coating methods. As the support, for example, a film or polyethylene-coated paper may be used, but a more preferable support is an aluminum plate that is polished and has an anodized film.

  In order to use a material having a photosensitive layer formed on a support as described above as a printing plate, an alkaline developer is obtained by subjecting the exposed part to exposure or laser scanning exposure and crosslinking the exposed part. Therefore, pattern formation is performed by eluting unexposed portions with an alkaline developer described later.

  The alkaline developer is not particularly limited as long as it is a solution that dissolves the polymer or binder resin according to the present invention, but preferably sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium metasilicate, An aqueous developer solution in which an alkaline compound such as potassium metasilicate, monoethanolamine, diethanolamine, triethanolamine, triethylammonium hydroxide, etc. is dissolved well dissolves the unexposed portion selectively, and the lower support surface is removed. It is extremely preferable because it can be exposed. Furthermore, it is also preferable to add various alcohols such as ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerin and benzyl alcohol to the alkaline developer. After developing with such an alkaline developer, normal gumming is preferably performed using gum arabic or the like.

  Next, synthesis examples of typical compounds of monomers having two or more phenyl groups substituted with vinyl groups in the molecule used in the present invention are shown below.

Synthesis example 1 (Synthesis example of monomer C-5)
A thirocyanuric acid 89g was suspended in 1.5 liters of methanol, and a 30% aqueous solution in which 84 g of potassium hydroxide was dissolved was gradually added while cooling to obtain a uniform solution. To this, 230 g of p-chloromethylstyrene was gradually added dropwise at room temperature so that the internal temperature did not exceed 40 ° C. Shortly after the addition, the product precipitated, but the stirring was continued, and after stirring for 3 hours, the product was separated by suction filtration. After washing with methanol and drying all day and night in a vacuum dryer, a compound represented by monomer C-5 was obtained in a yield of 90%.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples as well as the effects.

Using a grained anodized aluminum plate having a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation is applied on the plate so that the dry thickness is 2.0 microns. And drying for 6 minutes in a 75 ° C. dryer.
<Photosensitive coating solution>
Polymer 12 parts by weight Photoradical generator 1 part by weight Polymerizable compound 3 parts by weight (pentaerythritol triacrylate)
Sensitizing dye (S-20) 0.5 part by weight Dioxane 70 part by weight Cyclohexane 20 part by weight

  Various types of photosensitive materials were prepared by changing the polymer of the photosensitive coating solution and the type of the photoradical generator as shown in Table 1.

  The light-sensitive material (lithographic printing plate material) prepared 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 the exposure, development was performed with an alkaline developer containing 0.7% by weight of sodium metasilicate, and the sensitivity was evaluated based on whether or not 10-micron fine lines were clearly formed on the aluminum plate. The results are summarized in Table 1. In Table 1, ◯ means that a 10-micron fine line is clearly formed, and x means that it is not formed.

  In the above table, CP-1 represents an allyl methacrylate / benzyl methacrylate / methacrylic acid (molar ratio 60/20/20) copolymer, and CP-2, CP-3 and CP-4 are shown below.

  The above photosensitive material was evaluated for its performance as a printing plate. The printing durability was evaluated using a normal offset printing machine, ink, and fountain solution. The printing durability was evaluated based on the maximum number of printed sheets that did not change the print image quality. As a result, all the printing plates of the present invention were capable of printing 150,000 sheets.

As is clear from the above results, the reference photosensitive material containing both a polymer having a phenyl group substituted with a vinyl group in the side chain, a photo radical generator and a sensitizer is suitable for scanning exposure with blue semiconductor laser light. Therefore, a sharp and high printing durability relief image can be obtained without performing post-exposure heat treatment.

  The test was conducted in the same manner as in Example 1 except that the sensitizing dye in the photosensitive coating solution of Example 1 was changed to S-21. As a result, the same result as in Example 1 was obtained.

Using a grained anodized aluminum plate having a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation is applied on the plate so that the dry thickness is 2.0 microns. And drying for 6 minutes in a 75 ° C. dryer.
<Photosensitive coating solution>
Binder resin 10 parts by weight Photoradical generator (T-4) 1 part by weight Monomer or comparative compound of the present invention 4 parts by weight Sensitizing dye (S-20) 0.4 part by weight Dioxane 70 parts by weight Cyclohexane 20 parts by weight

  Various photosensitive materials were prepared by changing the binder resin of the photosensitive coating solution and the monomer or comparative compound of the present invention as shown in Table 2.

  The light-sensitive material (lithographic printing plate material) prepared 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 the exposure, development was performed with an alkaline developer containing 0.7% by weight of sodium metasilicate, and the sensitivity was evaluated based on whether or not 10-micron fine lines were clearly formed on the aluminum plate. The results are summarized in Table 2. In Table 2, ◯ means that a 10-micron fine line is clearly formed, and x means that it is not formed.

  In the above table, CP-1 represents an allyl methacrylate / benzyl methacrylate / methacrylic acid (molar ratio 60/20/20) copolymer, CC-1: styrene, CC-2: divinylbenzene, CC-3: diallylbenzene. , CC-4: pentaerythritol tetraacrylate, CC-5: tetraethylene glycol diacrylate.

The above photosensitive material was evaluated for its performance as a printing plate. The printing durability was evaluated using a normal offset printing machine, ink, and fountain solution. The printing durability was evaluated based on the maximum number of printed sheets that did not change the print image quality. As a result, each of the photosensitive materials (printing plates) 16 to 20 of the present invention can print 200,000 sheets, and the reference photosensitive materials (printing plates) 21 to 25 can print 150,000 sheets. It was.

As apparent from the above results, the monomer and the photo-radical generating agent having two or more phenyl groups substituted by a vinyl group in the binder resin and molecules, including sensitive light material further along a sensitizer, a blue semiconductor laser A relief image having a very high sensitivity to scanning exposure with light and a sharp and high printing durability can be obtained without performing post-exposure heat treatment. In particular, in accordance with the present invention, the printing durability is further improved by using a polymer having a phenyl group substituted with a vinyl group in the side chain as a binder resin.

Using a grained anodized aluminum plate having a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation is applied on the plate so that the dry thickness is 2.0 microns. And drying for 6 minutes in a 75 ° C. dryer.
<Photosensitive coating solution>
Polymer 12 parts by weight Photoradical generator 1 part by weight Polymerizable compound 3 parts by weight (pentaerythritol triacrylate)
Sensitizing dye (S-22) 0.5 part by weight Dioxane 70 part by weight Cyclohexane 20 part by weight

  Various types of photosensitive materials were prepared by changing the polymer of the photosensitive coating solution and the type of the photoradical generator as shown in Table 3.

The obtained photosensitive material was exposed as follows. That is, using an exposure machine (Mitsubishi Paper Hishira Copy Printer) with a tungsten lamp as the light source, an interference filter of 580 nm is interposed, and the amount of light passing through this interference filter is set to 5 mW / cm ^2. After adjusting, exposure was performed for 30 seconds through a control wedge (manufactured by Fuji Photo Film) having step wedges with a density difference of 0.15 intervals. A sample which was allowed to elapse within 1 minute and 1 hour after exposure was developed with an alkaline developer containing 0.7% by weight of sodium metasilicate. In the step wedge pattern formed on the aluminum plate after the development processing, the minimum number of step steps not remaining as an image was obtained as sensitivity. The larger this value, the higher the sensitivity. The results are summarized in Table 3.

  In the table, CP-1, CP-2, CP-3 and CP-4 are the same as in Table 1.

As is clear from the above results, the reference photosensitive material containing both a polymer having a phenyl group substituted with a vinyl group in the side chain, a photo radical generator and a sensitizer is extremely sensitive in the visible light region, A sharp relief image can be obtained without performing post-exposure heat treatment. In addition, reference is compared to the comparison, it can be seen that the latent image regression little.

Using a grained anodized aluminum plate having a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation is applied on the plate so that the dry thickness is 2.0 microns. And drying for 6 minutes in a 75 ° C. dryer.
<Photosensitive coating solution>
Binder resin 12 parts by weight Photoradical generator (T-8) 1 part by weight Monomer or comparative compound of the present invention 3 parts by weight Sensitizing dye (S-22) 0.5 part by weight Dioxane 70 parts by weight Cyclohexane 20 parts by weight

  Various photosensitive materials were prepared by changing the binder resin of the photosensitive coating solution and the monomer or comparative compound of the present invention as shown in Table 4.

  The obtained photosensitive material was evaluated in the same manner as in Example 4. The results are summarized in Table 4.

  In the table, CP-1, CC-1, CC-2, CC-3, CC-4 and CC-5 are the same as in Table 2.

As apparent from the above results, the monomer and the photo-radical generating agent having two or more phenyl groups substituted by a vinyl group in the binder resin and molecules, including sensitive light material further along a sensitizer, a visible light region Therefore, a sharp relief image can be obtained with extremely high sensitivity without performing post-exposure heat treatment. It can also be seen that the present invention has little latent image regression compared to the comparison. In particular, according to the present invention , by using a polymer having a phenyl group substituted with a vinyl group in the side chain as the binder resin, the sensitivity is further improved and the latent image regression is also improved.

Using an anodized aluminum plate having a graining treatment with a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation was applied thereon so that the dry thickness was 2 microns, and 70 Drying was performed for 6 minutes in a dryer at 0 ° C.
<Photosensitive coating solution>
Polymer 10 parts by weight Photoradical generator 2 parts by weight Polymerizable compound 3 parts by weight (pentaerythritol triacrylate)
Sensitizing dye 0.5 parts by weight Dioxane 70 parts by weight Cyclohexane 20 parts by weight

  Various photosensitive materials were prepared by changing the polymer of the photosensitive coating solution, the photoradical generator and the type of sensitizing dye as shown in Table 5.

The photosensitive material prepared as described above is wound around the outer surface of a cylindrical drum, and using a semiconductor laser with an output of 1.2 W (variable 0 to 1.2 W) that emits light at 830 nm, the drum rotation speed is 300 to 2000 rpm. 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 microns. Within 1 minute and 1 hour after exposure, when developing with an alkaline developer similar to that in Example 1, the minimum exposure energy required to clearly form a 10 micron line on the aluminum plate is the sensitivity of the photosensitive material. And expressed in units of mJ / cm ² (the smaller the value, the higher the sensitivity). The results are summarized in Table 5.

  In the table, the addition amount in the case of the combination of two kinds of photo radical generators is 1 part by weight, and CP-1, CP-2, CP-3 and CP-4 are the same as in Table 1.

The above photosensitive material was evaluated for its performance as a printing plate. The printing durability was evaluated using a normal offset printing machine, ink, and fountain solution. The printing durability was evaluated based on the maximum number of printed sheets that did not change the print image quality. As a result, all the reference printing plates had no problem even when printing 200,000 sheets. However, the comparative printing plate was not heat-treated, so that the printing durability was 10,000 sheets or less.

As is clear from the above results, the reference photosensitive material containing both a polymer having a phenyl group substituted with a vinyl group in the side chain, a photo radical generator, and a sensitizer is suitable for scanning exposure with near infrared laser light. On the other hand, a relief image with extremely high sensitivity and a sharp and high printing durability can be obtained without performing post-exposure heat treatment. In addition, reference is compared to the comparison, it can be seen that the latent image regression little.

Using an anodized aluminum plate having a graining treatment with a thickness of 0.24 mm, a photosensitive coating solution represented by the following formulation was applied thereon so that the dry thickness was 2 microns, and 70 Drying was performed for 6 minutes in a dryer at 0 ° C.
<Photosensitive coating solution>
Binder resin 10 parts by weight Photoradical generator 2 parts by weight Monomer or comparative compound of the present invention 3 parts by weight Sensitizing dye 0.5 parts by weight Dioxane 70 parts by weight Cyclohexane 20 parts by weight

  Various types of photosensitive materials were prepared by changing the types of the binder resin, the monomer of the present invention or the comparative compound, the photo radical generator and the sensitizing dye as shown in Table 6.

  The photosensitive material prepared as described above was evaluated in the same manner as in Example 8. The results are summarized in Table 6.

  In the table, CP-1, CC-1, CC-2, CC-3, CC-4 and CC-5 are the same as in Table 2.

The above photosensitive material was evaluated for its performance as a printing plate. The printing durability was evaluated using a normal offset printing machine, ink, and fountain solution. The printing durability was evaluated based on the maximum number of printed sheets that did not change the print image quality. As a result, the printing plate of the present invention及beauty references are all but also no problem with 200,000 sheets of printing, the printing plate of the comparison, because it did not heat treated, printing durability was less than 10,000 sheets.

As apparent from the above results, the binder resin, monomer and photo-radical generator having two or more phenyl groups substituted by a vinyl group in the molecule, is including sensitive light material further along a sensitizer, a near A very high-sensitivity relief image with high sensitivity to scanning exposure with external laser light can be obtained without post-exposure heat treatment. Compared to or compared, it can be seen that the latent image regression little. Further, according to the present invention, by using a polymer having a phenyl group substituted with a vinyl group in the side chain as a binder resin, the latent image regression is further improved with higher sensitivity.

Claims (5)

A polymer having a phenyl group substituted with a vinyl group in the side chain , wherein the phenyl group is bonded to the main chain through a linking group (provided that the side chain has a linking group containing a heterocyclic ring). Polymer having a phenyl group substituted with a vinyl group and polyurethane resin), a monomer having two or more phenyl groups substituted with a vinyl group in the molecule, an organic boron salt and a trihaloalkyl-substituted compound as a photoradical generator And a sensitizer that absorbs in the wavelength region from visible light to infrared light and sensitizes the photoradical generator.
In the polymer and the monomer, the phenyl group may be substituted with a substitutable group or atom other than a vinyl group, and the vinyl group may be substituted. The photosensitive composition according to claim 1, which is for scanning exposure. The photosensitive composition according to claim 1, which is used for a near infrared laser having a wavelength of 750 to 1100 nm. The photosensitive composition according to claim 1, which is for a blue semiconductor laser having a wavelength of 400 to 430 nm. A photosensitive lithographic printing plate material comprising the photosensitive composition according to any one of claims 1 to 4 .