JP2007256445A - Photopolymerizable composition and photosensitive lithographic printing plate material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition which ensures high image quality, high sensitivity and excellent storage stability, to also provide a photosensitive lithographic printing plate material using the same and having good printing durability, and to further provide a material which is good in all of image quality, sensitivity and storage stability as a direct drawing photosensitive material using laser light emitted in a near-infrared region (700-900 nm), and which is excellent in printing property as a direct drawing lithographic printing plate material for an infrared-laser. <P>SOLUTION: The photopolymerizable composition comprises a photopolymerization initiator, an ethylenically unsaturated double bond compound and a polymer binder, wherein the photopolymerization initiator is an organic boron salt having two or more organic boron anions within a molecule and forming the salt with counter cations having a structure represented by formula 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 capable of forming an image using a laser and a photosensitive lithographic printing plate material. 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 particular, the present invention relates to a negative photosensitive lithographic printing plate having sensitivity to light in a wavelength range from near infrared light of 750 nm or more to infrared light.

  In addition to conventional photosensitive resins that are exposed to UV light exposure and form images, and lithographic printing plates that use them, there is a highly sensitive photosensitive resin system that greatly improves the sensitivity to light in the visible light region. A system capable of direct drawing and plate making using a laser using a light source such as an argon ion laser (488 nm) or an FD-YAG laser (532 nm) has been put into practical use. These have a photopolymerization initiator, a dye sensitizer, and a polymerizable compound. The photoenergy absorbed by the dye sensitizer is used for radical cleavage of the photopolymerization initiator, and the polymerizable compound is polymerized by the generated radicals. Is to be used.

  In addition to visible light lasers as exposure light sources, high-power semiconductor lasers and YAG lasers that emit light in the region of 750 nm or more have come to be used as light sources. Development has been actively carried out.

  Problems common to the direct-drawing photopolymerization system using various laser beams as described above include the problem of high sensitivity and storage stability. That is, in order to improve the recording speed, it is inevitably desired to increase the sensitivity of the photoconductor, but on the other hand, there is a problem that the sensitivity decreases during storage of the photoconductor over time, thermal fogging occurs, and non-image areas. However, since it adheres firmly to a support (aluminum or the like) over time, there are problems such as poor elution during development.

  As for a specific combination of a photopolymerization initiator and a sensitizer constituting the above photopolymerization system, for example, a combination of an organic boron anion and a cationic dye is disclosed in JP-A-62-143044 (Patent Document 1), No. 2000-89455 (Patent Document 2) and the like. As another example of the combination, a combination of a trihaloalkyl-substituted triazine compound and a cyanine dye is described in JP-A-2-189548 (Patent Document 3) and the like.

  Even in the various photopolymerization systems as described above, the present situation is that no system has yet been found that has both sufficient sensitivity and storage stability. Of these, many studies have been made on the photopolymerization system containing an organic boron salt in particular because it is highly sensitive and relatively less susceptible to the influence of oxygen. Many problems remained, such as the promotion of decomposition by the presence of. JP-A-2000-86670 (Patent Document 4) discloses thermal stabilization in a solution state of a photosensitive composition by adding a nitrogen-containing heterocyclic compound, an amino group-containing compound or a thiol compound as a stabilizer for an organic boron salt. Although measures for improving the properties are described, the effects of these additives are not recognized in the state of a solid phase in which the photosensitive composition is applied and dried, and problems remain in practice.

To solve these problems, JP-A-2002-287350 (Patent Document 5) has already disclosed an ethylenically unsaturated bond compound having an onium cation group and / or the polymer as a counter cation for an organic boron anion. It has been shown that the use of a binder improves the stability of the boron salt and forms a highly sensitive photopolymerization system. However, when such a system is applied to printing plate applications, the printing durability does not necessarily reach a satisfactory level, and the image quality is widened and the problem of poor dot reproducibility remains.
JP-A-62-143044 JP 2000-89455 A Japanese Patent Laid-Open No. 2-189548 JP 2000-86670 A JP 2002-287350 A

  An object of the present invention is to provide a photosensitive composition having high image quality, high sensitivity, and excellent storage stability, and further to provide a photosensitive lithographic printing plate material having good printing durability using the same. is there. Furthermore, all of the image quality, sensitivity and storability are good as a direct-drawing type photosensitive material by laser light emitting in the near-infrared region (700 to 900 nm), and printability as a direct-drawing planographic printing plate material for near-infrared laser It is to provide an excellent material.

  As a result of intensive studies to solve the above problems, the present inventor has found that in a system containing a photopolymerization initiator, an ethylenically unsaturated double bond compound and a polymer binder, the photopolymerization initiator is present in the molecule. It has been found that the above problem can be basically solved by using an organic boron salt which forms a salt with a counter cation having two or more organic boron anions and having a structure represented by the general formula 1. The invention has been reached.

In the general formula 1, R ₁ and R ₂ each represents an optionally substituted alkyl group. L ₁ represents any divalent linking group.

  The present invention provides a photosensitive composition having high image quality, high sensitivity, and excellent storage stability, and further provides a photosensitive lithographic printing plate material having good printing durability using the same. Furthermore, all of the image quality, sensitivity and storability are good as a direct-drawing type photosensitive material by laser light emitting in the near-infrared region (700 to 900 nm), and printability as a direct-drawing planographic printing plate material for near-infrared lasers. Excellent material is provided.

  Hereinafter, the present invention will be described in detail. The organic boron salt used in the present invention is a photosensitive composition characterized in that a salt is formed between two or more organic boron anions and a counter cation having the above structure in the molecule.

  The organic boron anion used in the present invention is represented by the following general formula 2.

In the formula, each of R ₃ , R ₄ , R ₅ and R ₆ may be the same or different, and may be an alkyl group (for example, methyl group, ethyl group, n-propyl group, n -Butyl group, tert-butyl group, n-hexyl group, stearyl group etc.), aryl group (eg phenyl group, 1-naphthyl group etc.), aralkyl group (eg benzyl group etc.), alkenyl group (eg vinyl Group), alkynyl group (for example, ethynyl group, propynyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), heterocyclic group (for example, pyridyl group, etc.), Alkyl group, alkoxy group, hydroxy group, amino group, alkylamino group, acyl group, acyloxy group, carboxy group, alkoxycarbonyl group, cyano group, Examples include a rogenated alkyl group and a halogen atom. Among these, an alkyl group having 10 or less carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group are preferable. R _{3 to} R ₆ are more preferably a combination of an alkyl group and an aryl group, and particularly preferably one is an alkyl group which may be substituted, and the other three may be substituted. This is the case.

  Preferable specific examples of these organic boron anions include, for example, n-butyl-triphenyl boron anion, n-hexyl-triphenyl boron anion, n-butyl-tris (p-methylphenyl) boron anion, n-butyl- Tris (2,4,6-trimethylphenyl) boron anion, n-butyl-tris (p-methoxyphenyl) boron anion, n-butyl- (p-chlorophenyl) boron anion, n-butyl-tris (m-fluorophenyl) ) Boron anion, n-butyl-tris (2,6-difluorophenyl) boron anion, n-butyl-tris (2,4,6-trifluorophenyl) boron anion, n-butyl-tris (m-trifluoromethyl) Phenyl) boron anion, n-butyl-trinaphthylboron On, n- hexyl trinaphthyl borate anion, n- butyl - tris (4-methylnaphthyl) but boron anion and the like, but is not limited thereto.

  The compound of the present invention used by forming a salt with the above organic boron anion is represented by the following general formula 3.

In the formula, n represents an integer of 2 or more, and X ⁻ represents the organoboron anion represented by Formula 2 above.

In the formula, L ₂ has the same meaning as L ₁ used in Formula 1, and represents any divalent linking group, and specifically, an alkylene group (eg, methylene group, ethylene group) which may be substituted. , Propylene group, hexamethylene group, etc.), arylene group (eg, p-phenylene group, m-phenylene group, 1,5-naphthylene group, 4,4′-biphenylene group, etc.), alkyleneoxy group (eg, ethyleneoxy) Group, propyleneoxy group, diethyleneoxy group, etc.), —O—, —S—, —NR ₉ —, —CO—, —COO—, —OCO—, —SO ₂ —, —CONR ₉ —, —NR _{9 CO -, - OCONR 9 -,} NR 9 COO -, - NR 10 CONR 9 -, - NR 9 COCONR 10 -, - SO 2 NR 9 -, - NR 9 SO 2 - (R 9 and R ₁₀ are the same May or may not be different, each hydrogen Child, optionally substituted alkyl group, an aryl group, an acyl group, an alkylsulfonyl group.), And the like, these linking groups may be combined alone any two or more even. Preferable examples of the linking group L ₂ include structures represented by the following chemical formulas 4 and 5.

In General Formula 3, R ₇ and R ₈ have the same meanings as R ₁ and R ₂ used in Chemical Formula _1, and R ₇ and R ₈ may be the same or different, and are substituted. Alkyl group (for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, tert-butyl group, n-hexyl group, allyl group, propargyl group, hydroxymethyl group, hydroxy group) An ethyl group, a cyanoethyl group, a chloroethyl group, a methoxyethyl group, an acetoxyethyl group, an ethoxycarbonylmethyl group, an acryloyloxyethyl group, a methacryloyloxyethyl group, a 4-vinylbenzyl group, a 3-vinylbenzyl group and the like are represented.

  The salt of the organic onium cation group and the organic boron anion can be synthesized by a conventionally known method. Typically, a corresponding organic onium cation group and an organic group are converted into organic compounds by a salt exchange reaction between a desired organic onium salt having a halogen anion or a sulfonate anion as a counter anion and a desired organic boron salt having a tetraalkylammonium as a counter cation. Salts with boron anions can be formed.

  Preferable examples of the compound having the structure represented by the general formula 3 include the following examples. The synthesis method of these compounds will be shown in the synthesis examples described later.

  In the formula, m represents an integer of 2 or more.

  In the formula, l represents an integer of 2 or more.

  Among these exemplified compounds, particularly preferable compounds are quaternary ammonium groups in which a vinylbenzyl group is substituted on polyethyleneimine (molecular weight is preferably about 100 to 100,000) as shown in Chemical Formula 9 and the corresponding synthesis examples described later. The compound synthesize | combined by adding the acrylic acid ester derivative which has is mentioned. Alternatively, a compound similarly synthesized by adding to polyallylamine as shown in Chemical formula 10 can also be used very preferably.

  As described above, when synthesizing the compound of the present invention using polyethyleneimine or polyallylamine as a raw material, a group having another structure in the repeating unit (in particular, a group having a polymerizable double bond). It is also very preferable to introduce (preferably). Examples of such cases include the following compounds.

  In formula, x represents the molar ratio in a repeating unit, and represents arbitrary numerical values in the range of 0 to 0.99.

  In formula, y represents the molar ratio in a repeating unit, and represents the arbitrary numerical values in the range of 0-0.99.

  There is a preferred range for the proportion of the organic boron salt of the present invention contained in the photosensitive composition, and the organic boron salt is 0.1 to 50 parts by mass in 100 parts by mass of the solid content of the photosensitive composition. It is preferable that it is contained in the range.

  As a photoinitiator in this invention, the organic boron salt of this invention may be used independently as a photoinitiator, and may be used in combination with another photoinitiator. Examples of photopolymerization initiators that can be combined include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) keto Examples include oxime ester compounds, (f) azinium compounds, (g) active ester compounds, (h) metallocene compounds, (i) trihaloalkyl-substituted compounds, and (j) organoboron compounds. Of these, (i) trihaloalkyl-substituted compounds are particularly preferred because of their high sensitivity.

  Preferable examples of (a) aromatic ketones as photopolymerization initiators that can be combined include "RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY" J. P. FOUASSIER, J.A. F. RABEK (1993), p. 77-P. A compound having a benzophenone skeleton or a thioxanthone skeleton described in 177, an α-thiobenzophenone compound described in JP-B-47-6416, a benzoin ether compound described in JP-B-47-3981, and a compound described in JP-B-47-22326 α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, p-di (dimethylaminobenzoyl) benzene described in JP-A-2-211452, and thio-substitution described in JP-A-61-194062 Aromatic ketone, acylphosphine described in JP-B-2-9597 Insulphines, acylphosphines described in JP-B-2-9596, thioxanthones described in JP-B-63-61950, and coumarins described in JP-B-59-42864.

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

  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- Butyl peroxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra- (tert-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (tert-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′- Peroxyesters such as tetra (p-isopropylcumylperoxycarbonyl) benzophenone and di-tert-butyldiperoxyisophthalate are preferred. There.

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

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

  (F) Examples of azinium salt compounds include JP-A-63-138345, JP-A-63-142345, JP-A-63-142346, JP-A-63-143537, and JP-B-46-42363. The compound group which has the described N-O bond can be mentioned.

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

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

  Examples of (i) trihaloalkyl-substituted compounds include U.S. Pat. Nos. 3,954,475, 3,987,037, 4,189,323, JP-A 61-151644, and JP-A 61-151644. Trihalomethyl-s-triazine compounds described in JP-A-63-298339, JP-A-4-69661, JP-A-11-153859, etc., JP-A-54-74728, JP-A-55-77742, JP-A-5-77742 Examples thereof include 2-trihalomethyl-1,3,4-oxadiazole derivatives described in JP-A-60-138539, JP-A-61-143748, JP-A-4-362644, JP-A-11-84649, and the like. Moreover, the trihaloalkylsulfonyl compound as described in Japanese Patent Application No. 2000-223304 etc. which this trihaloalkyl group couple | bonded with the aromatic ring or the nitrogen-containing heterocyclic ring through the sulfonyl group is mentioned. Of these, examples of particularly preferred compounds are shown below.

  (J) Examples of the organic boron compound include organic compounds 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. Boron ammonium compounds, organoboron sulfonium compounds and organoboron oxosulfonium compounds described in JP-A-6-175561, JP-A-6-175564, JP-A-6-157623, etc., JP-A-6-175553, JP-A-6-175 Organoboron iodonium compounds described in JP-A No. 175554, etc., organic boron phosphonium compounds described in JP-A No. 9-188710, JP-A Nos. 6-348011, JP-A Nos. Organoboron transition described in JP-A-292014, JP-A-7-306527, etc. Shokuhai coordination complex compounds.

  There is a preferred range for the ratio of the photopolymerization initiator contained in the photosensitive composition, and the photopolymerization initiator is 0.1 to 50 parts by mass in 100 parts by mass of the solid content of the photosensitive composition. It is preferable that it is included in the range.

  Examples of the ethylenically unsaturated double bond compound in the present invention include a polymerizable compound having at least one polymerizable double bond in the molecule, and the organic boron salt of the present invention can be used alone. It may be used in combination with other ethylenically unsaturated double bond compounds.

  Among the ethylenically unsaturated double bond compounds that can be combined, it is particularly preferable to use a polyfunctional ethylenically unsaturated double bond compound having two or more polymerizable double bonds in the molecule. The unsaturated double bond compound is not particularly limited, and examples thereof include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate, trisacryloyloxyethyl isocyanate. Nurate, tripropylene glycol diacrylate, ethylene glycol glycerol triacrylate, glycerol epoxy triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol Multifunctional acrylic acid ester monomers such as traacrylate, polyfunctional methacrylic acid ester monomers in which the acrylates of these exemplary compounds are replaced by methacrylates, as well as itaconic acid ester monomers, crotonic acid ester monomers, maleic acid ester monomers, etc. Is mentioned.

  Examples of other ethylenically unsaturated double bond compounds that can be combined include styrene derivatives, and it is particularly preferable to use a compound having two or more vinylphenyl groups in the molecule. 4-divinylbenzene, 1,4-diisopropenylbenzene, 1,4-bis (4-vinylbenzyloxy) benzene, 1,2,3-tris (4-vinylbenzyloxy) benzene, 1,3,5- Tris (4-vinylbenzyloxy) benzene, 2,2-bis [4- (4-vinylbenzyloxy) phenyl] propane, 1,1,2,2-tetrakis [4- (4-vinylbenzyloxy) phenyl] Ethane, α, α, α ′, α′-tetrakis [4- (4-vinylbenzyloxy)] p-xylene, 1,2-bis (4-vinylbenzylthio) e 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, etc. However, it is not limited to these.

  In addition, oligomers having radical polymerizability are also preferably used in place of the above-mentioned polymerizable compounds, and polyesters (meth) acrylates, urethane (meth) acrylates, epoxy (meth) acrylates and the like as various oligomers into which acryloyl groups and methacryloyl groups have been introduced. Are also used in the same manner, but these can also be preferably used as ethylenically unsaturated compounds.

  There is a preferred range regarding the proportion of the ethylenically unsaturated compound as described above in the photosensitive composition, and the ethylenically unsaturated compound is 1 to 60 parts by mass in 100 parts by mass of the total photosensitive composition. It is preferably included in the range, and more preferably in the range of 5 to 50 parts by mass.

  Although it does not specifically limit as a polymer binder in this invention, It is preferable that it is soluble in alkaline aqueous solution. Specifically, 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 ester, Carboxylic acid group-containing monomers such as 4-carboxystyrene and acrylamide-N-glycolic acid and their salts, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, styrene sulfonic acid, 2-sulfoethyl methacrylate, 3-sulfopropyl Sulphonic acid group-containing monomers such as methacrylate, 2-acrylamido-2-methylpropanesulfonic acid and their salts, Phosphoric acid group-containing monomers such as vinylphosphonic acid and their salts, allylamine, diallylamine, 2-dimethylamino Ethyl acrylate, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl acrylate, 2-diethylaminoethyl methacrylate, 3-dimethylaminopropyl acrylamide, 3-dimethylaminopropyl methacrylamide, 4-aminostyrene, N, N-dimethyl-N- Amino group-containing monomers such as (4-vinylbenzyl) amine, N, N-diethyl-N- (4-vinylbenzyl) amine and their quaternary ammonium salts, 4-vinylpyridine, 2-vinylpyridine, N-vinyl Nitrogen-containing heterocycle-containing monomers such as imidazole and N-vinylcarbazole and their quaternary ammonium salts, acrylamide, methacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-die (Meth) acrylamides such as ruacrylamide, N-isopropylmethacrylamide, diacetoneacrylamide, N-methylolacrylamide, 4-hydroxyphenylacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2 -Hydroxyalkyl (meth) acrylates such as hydroxypropyl methacrylate and glycerol monomethacrylate, methacrylic acid methoxydiethylene glycol monoester, methacrylic acid methoxypolyethylene glycol monoester, methacrylic acid polypropylene glycol monoester and the like (meth) acrylates Water selected from N-vinylpyrrolidone, N-vinylcaprolactam, etc. Or the vinyl polymer comprised from a monomer soluble in alkaline aqueous solution can be used, These may be used independently and may be used as arbitrary 2 or more types of copolymers.

  Furthermore, in order to form a copolymer with a monomer soluble in the alkaline aqueous solution as described above, another monomer may be used in combination. Examples of these include styrene, 4-methylstyrene, 4-hydroxystyrene, Styrene derivatives such as 4-acetoxystyrene, 4-chloromethylstyrene, 4-methoxystyrene, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, Alkyl (meth) acrylates such as dodecyl methacrylate, aryl (meth) acrylates such as phenyl methacrylate and benzyl methacrylate, or arylalkyl (meth) acrylates, acrylic Nitrile, methacrylonitrile, phenylmaleimide, hydroxyphenylmaleimide, vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl benzoate and other vinyl esters, methyl vinyl ether, vinyl ether such as butyl vinyl ether, In addition, various monomers such as acryloylmorpholine, tetrahydrofurfuryl methacrylate, vinyl chloride, vinylidene chloride, allyl alcohol, vinyltrimethoxysilane, glycidyl methacrylate, and the like, a copolymer composed of any combination thereof can be used in the present invention. Can be used as a polymer binder.

  The case where the structure of the polymer binder in the present invention has a substituent reactive to radicals generated from the photopolymerization initiator is also preferably used. For example, the case where a polymerizable double bond is introduced into a polymer side chain is particularly preferably used because it provides a highly sensitive negative photosensitive composition. Furthermore, in the case of having a phenyl group substituted with a vinyl group as a polymerizable double bond contained in the side chain, it is not easily affected by oxygen, and is high without providing an overcoat layer such as polyvinyl alcohol on the photosensitive layer. This is extremely preferable because it provides a sensitive negative photosensitive material. Specific examples of preferred polymer binders include alkali-soluble polymers described in Japanese Patent Application No. 2000-223304. Examples of polymers that can be preferably used in the present invention are shown below. The numerical value in a formula represents 100% mass ratio of each repeating unit.

  There is a preferred range for the molecular weight of the polymer constituting the polymer binder in the present invention, 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 5,000 to 500,000. .

  A sensitizing dye can be separately added to the photosensitive composition of the present invention for the purpose of imparting photosensitivity in the wavelength range from visible light to infrared light.

  As for the preferred sensitizing dyes that can be used in the photosensitive composition of the present invention, cationic dyes, anionic dyes and neutral dyes having no charge are merocyanine, coumarin, xanthene, thioxanthene, azo dyes, etc. it can. Among these, particularly preferable examples are dyes selected from cyanine, carbocyanine, hemicyanine, methine, polymethine, triarylmethane, indoline, azine, thiazine, xanthene, oxazine, acridine, rhodamine and azamethine dyes as cationic dyes. is there. In combination with these cationic dyes, they are particularly preferably used because of their high sensitivity and excellent storage stability.

  Further, the present invention can provide a photosensitive composition for a lithographic printing plate having photosensitivity in a wavelength region of infrared light from near infrared light of 750 nm or more, which has been actively developed in recent years. The sensitizing dye in this case is required to have absorption in the wavelength range from near infrared light to infrared light, and preferable examples of the dye used for such purpose include US Pat. No. 4,973,572. , JP-A-10-230582, JP-A-11-153589, JP-A-2000-103179, JP-A-2000-187322, etc. Among these, particularly preferable dyes are cyanine dyes, Examples thereof include polymethine dyes and squarylium dyes.

  Although the specific example of the sensitizing dye which can be used preferably is shown below, this invention is not limited to these.

  In the quantitative ratio of the sensitizing dye and the photopolymerization initiator as described above, the photopolymerization initiator is used in the range of 0.01 parts by mass to 100 parts by mass with respect to 1 part by mass of the sensitizing dye. preferable. More preferably, the photopolymerization initiator can be used in the range of 0.1 to 50 parts by mass.

  As another element constituting the photosensitive composition, addition of a polymerization inhibitor can also be preferably performed. Examples of the polymerization inhibitor include compounds such as quinone and phenol, and specifically, hydroquinone, p-methoxyphenol, catechol, tert-butylcatechol, 2-naphthol, 2,6-di-tert. A compound such as -butyl-p-cresol is preferably used. These polymerization inhibitors are preferably used in the range of 0.001 to 0.1 parts by mass with respect to 1 part by mass of the ethylenically unsaturated compound described above.

  As another element constituting the photosensitive composition, a colorant can also be preferably added. The colorant is used for the purpose of enhancing the visibility of the image area after exposure and development processing, and includes carbon black, phthalocyanine dyes, triarylmethane dyes, anthraquinone dyes, azo dyes, and the like. Various dyes and pigments can be used, and it is preferably used in the range of 0.005 to 0.5 parts by mass with respect to 1 part by mass of the binder.

  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 the image after development.

  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 applied onto a support and dried using various known coating methods. As for 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, contact exposure or laser scanning exposure is performed on the material, and the exposed portion is cross-linked to develop a solution. Since solubility decreases, pattern formation is performed by removing an unexposed part with a developing solution.

  A particularly preferable laser light source used for laser scanning exposure in the present invention is a laser having an oscillation wavelength in the near infrared region, and a solid laser such as various semiconductor lasers, YAG lasers and glass lasers is most preferable.

  The developer is not particularly limited as long as it is a solution that dissolves the polymer binder in the present invention, but sodium hydroxide, potassium hydroxide, sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, monoethanolamine An aqueous alkaline developer in which an alkaline compound such as diethanolamine, triethanolamine or tetramethylammonium hydroxide is dissolved, and an aqueous developer not containing the aforementioned alkaline compound are preferred. Furthermore, various alcohols such as ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, glycerin, and benzyl alcohol may be added to the developer. After developing with such a developer, normal gumming is preferably performed using gum arabic or the like.

  An important point as one of the effects of the present invention is that the exposed portion has a high cross-linking density and gives a high-sensitivity image reproduction as a photosensitive property, and can be particularly preferably used as a photosensitive composition for laser scanning exposure. It is. In particular, when a near-infrared semiconductor laser emitting near 830 nm is used as the light source, the edge portion of the image is reproduced sharply and gives high-resolution image quality, so that it can be used very preferably.

  Hereinafter, the present invention will be described in more detail with reference to synthesis examples and examples, but the present invention is not limited to these examples. As the polymer and styryl monomer described in the examples, those obtained by the method described in JP-A No. 2001-290271 were used. In addition, the number of parts and percentage in an Example are based on mass.

Synthesis Example 1 (Synthesis Example of Chemical Formula 6)
A quaternary salt acrylate compound obtained by reacting N, N-diethylaminoethyl acrylate and p-chloromethylstyrene (manufactured by Seimi Chemical Co., Ltd., CMS-14) in equimolar methanol by a conventional method is converted to N, N-bis ( 4-Equivalents to 3-aminopropyl) methylamine were added and reacted in methanol at 50 ° C. for 24 hours to synthesize the compounds shown below.

  To a methanol solution containing 50% by mass of the above compound, a dioxane solution containing 40% by mass of equimolar tetra-n-butylammonium (n-butyltriphenylborate) (Showa Denko, P3B) is added and heated at 50 ° C. While stirring, methanol was gradually added until the total volume doubled. The compound shown in Chemical formula 6 was obtained by transferring to an ice-cold water bath and cooling.

Synthesis Example 2 (Synthesis Example of Chemical Formula 7)
Quaternary salt obtained by reacting N, N-dimethylaminoethyl acrylate with m, p-chloromethylstyrene (CMS-p, manufactured by Seimi Chemical Co., Ltd.) in equimolar methanol in exactly the same manner as in Synthesis Example 1. The compound obtained by adding 4 equivalents of an acrylate compound to N, N-bis (3-aminopropyl) methylamine and reacting in methanol at 50 ° C. for 24 hours was used. Compound of the chemical formula 7 in exactly the same manner using tetra-n-butylammonium (n-butyltrinaphthylborate) (N3B, Showa Denko) instead of -n-butylammonium (n-butyltriphenylborate) Got.

Synthesis Example 3 (Synthesis Example of Chemical Formula 8)
In Synthesis Example 1, 1,4-bis (3-aminopropyl) piperazine was used instead of N, N-bis (3-aminopropyl) methylamine, and N, N-diethylaminoethyl acrylate was replaced with N, N -The compound of Formula 8 was synthesized in the same manner except that dimethylaminoethyl acrylate was used.

Synthesis Example 4 (Synthesis Example of Chemical Formula 9)
In Synthesis Example 1, N, N-dimethylaminoethyl acrylate was used in place of N, N-diethylaminoethyl acrylate, and N, N-bis (3-aminopropyl) methylamine was replaced with polyethyleneimine. Epomin SP-006 (molecular weight 600, amine ratio: primary: secondary: tertiary = 35: 35: 30) and tetra-n-butylammonium (n-butyltrinaphthyl borate) (N3B, Showa Denko) The compound of Chemical Formula 9 was synthesized in the same manner except that was used.

Synthesis Example 5 (Synthesis Example of Chemical Formula 10)
In Synthesis Example 1, N, N-dimethylaminoethyl acrylate was used instead of N, N-diethylaminoethyl acrylate, and 1/2 equivalent of polyallylamine was used instead of N, N-bis (3-aminopropyl) methylamine. The compound of Formula 10 was prepared in exactly the same manner except that Nittobo Co., Ltd., PAA-01, molecular weight 1000) and tetra-n-butylammonium (n-butyltrinaphthylborate) (Showa Denko, N3B) were used. Synthesized.

Synthesis Example 6 (Synthesis Example of Chemical Formula 11)
Epomin SP-200 (molecular weight 10,000, amine ratio: first grade: second grade: third grade = 35: 35: 30) obtained from Nippon Shokubai Co., Ltd. was used as polyethyleneimine. CMS-p (meta isomer: para isomer = 50: 50) obtained from Seimi Chemical Co., Ltd. was used as chloromethylstyrene. In a 1-liter flask equipped with a stirrer and a thermometer, 20 grams of Epomin SP-200 was added, and 23 grams of sodium hydroxide and 100 grams of distilled water were added to make a uniform solution. While maintaining the internal temperature at 50 ° C. on a water bath, 88 g of CMS-p was added and vigorous stirring was performed. The internal temperature was raised to 70 ° C., and the mixture was stirred at this temperature for 4 hours. After cooling to room temperature, the whole was transferred to 1 liter of ion exchange water, and the precipitated viscous solid was washed with water and further washed with methanol. As a result, a slightly yellowish white viscous solid was obtained. This was dissolved in dioxane, 55 g of N, N-dimethylaminoethyl acrylate was added, and the mixture was continuously heated and stirred at 50 ° C. for 24 hours. Time reaction was performed. The reaction mixture was transferred into 1 liter of diisopropyl ether, and the precipitated solid was thoroughly washed. As a result of analyzing the structure by proton NMR after vacuum drying, it was identified as a compound represented by Chemical Formula 11. In this synthesis example, the value of x in Chemical formula 11 was about 0.6.

Synthesis Example 7 (Synthesis Example of Chemical Formula 12)
Epomin SP-018 (molecular weight 1,800, amine ratio: first grade: second grade: third grade = 35: 35: 30) obtained from Nippon Shokubai Co., Ltd. was used as polyethyleneimine. Karenz MOI obtained from Nippon Shokubai Co., Ltd. was used as 2-methacryloyloxyethyl isocyanate. In a 1 liter flask equipped with a stirrer and a thermometer, 75 g of Epomin SP-018 was added, and 450 g of diethylene glycol dimethyl ether was added to obtain a uniform solution. The internal temperature was kept at 10 ° C. on an ice-water bath, and 103 g of Karenz MOI was gradually added dropwise, and the dropping rate was adjusted so that the internal temperature did not exceed 20 ° C. After completion of the dropwise addition, the mixture was further stirred at room temperature for 12 hours, and after removing the solvent by distillation under reduced pressure, the resulting viscous oily substance was dissolved in dioxane, and 129 grams of N, N-dimethylaminoethyl acrylate was added. After heating and stirring at 50 ° C. for 24 hours, 138 grams of m, p-chloromethylstyrene was added, and the reaction was further performed at 70 ° C. for 4 hours. The reaction mixture was transferred into 2 liters of diisopropyl ether, and the precipitated solid was thoroughly washed. As a result of analyzing the structure by proton NMR after vacuum drying, it was confirmed that the compound was as shown in Chemical formula 12. In this synthesis example, the value of y in Chemical formula 12 was about 0.5.

Using an anodized aluminum plate that has been grained with a thickness of 0.24 mm, a photosensitive coating solution represented by the following prescription is applied thereon so that the dry thickness is 2.5 μm, The photosensitive lithographic printing plate material was prepared by drying in an oven at 80 ° C. for 5 minutes.
<Photosensitive coating solution>
Polymer binder (P-1 in Chemical formula 15) 10 parts Photopolymerization initiator of the present invention (Table 1 below) 3 parts Photopolymerization initiator (T-4 in Chemical formula 13) 0.5 parts Pentaerythritol tetraacrylate 3 Part
10% phthalocyanine dispersion (colorant) 0.5 part Sensitizing dye (S-33 in Chemical formula 19) 0.3 part Methylenebis (2,6-di-t-butylphenol) 0.1 part Dioxane 80 parts Cyclohexanone 5 parts

  Various photosensitive lithographic printing plate materials were prepared using the photopolymerization initiator according to the present invention in the photosensitive coating solution as shown in Table 1. At the same time, except that the compound according to the present invention is not used, the samples of Comparative Examples 1 and 2 were used in the same manner as in the photosensitive coating liquid formulation except that the comparative photopolymerization initiator shown in Table 2 was used. Created in exactly the same way. In addition, as a photopolymerization initiator for comparison, compounds described in JP-A No. 2002-287350 (Chemical Formula 22 to Chemical Formula 26) were used.

The obtained photosensitive material was exposed using a PT-R4000 (drawing apparatus equipped with a 830 nm laser) manufactured by Dainippon Screen Mfg. Co., Ltd. according to the exposure amount irradiated to the plate surface of 120 mJ / cm ² . . The exposed photosensitive lithographic printing plate material was developed using a developer prepared as follows (development time was 15 seconds, developer temperature was 30 ° C.).

(Developer formulation)
Dimethylaminoethyl alcohol 30 parts Tetramethylammonium hydroxide 15 parts Butyl naphthalene sulfonate 10 parts Add water to adjust the total volume to 1000 parts

(Prepress image evaluation)
As an evaluation image, a 175-line mesh image (changed in the range of dot area ratio from 1 to 95%) was subjected to laser exposure on the sample at a resolution of 2400 dpi. The halftone dot area ratio of the plate-making product was measured using X-Rite, Inc. PlateDot, and the image quality was evaluated by comparing with the theoretical value (set value). The smaller the difference between the theoretical value and the measured value, the less the line was thickened and the better the image quality. The results are summarized in Table 3. In each of the examples, the difference from the theoretical value was smaller than that in the comparative example, and good image quality was exhibited.

(Print test)
In order to perform normal offset printing using the sample developed as described above, Ryobi-560 is used as the printing press, black ink for offset printing is used as the printing ink, and the hygroscopic liquid is Toyo Ink Co., Ltd. A 1% aqueous solution of a hygroscopic liquid AQUAUNITY WKK for offset printing was used. For printing evaluation, use a reflection densitometer DM-620 manufactured by Dainippon Screen Mfg. Co., Ltd. after wiping off the ink with a cleaner solution every time the reflection density of the solid part in the test image on the printing plate is measured. The printing durability was evaluated by measuring the decrease in reflection density before and after printing. It was separately confirmed that when the reflection density of the solid portion on the printing plate reached about 0.5, the ink deposition property deteriorated and the ink was not partially applied. The results are summarized in Table 4. When all of the photosensitive lithographic printing plates of the present invention were used, good prints were obtained even with 50,000 sheets of printing durability, and film slippage in the image area on the printing plate was slight. . In addition, good results were obtained with no soiling. In Comparative Examples 1 and 2, noticeable image part film slipping had already occurred in 10,000 sheets of printing, and partial ink failure occurred. In other comparative examples, no problem was observed even when the number of printed sheets was 50,000, but the reflection density of the printing plate after printing was greatly reduced.

(Preservation test)
The photosensitive material prepared above was left in a dark place for 4 weeks in an atmosphere of a temperature of 40 ° C. and a relative humidity of 80% to evaluate developability and sensitivity. Evaluation of developability was performed by using the developer shown above, changing the development time up to 24 seconds at intervals of 4 seconds at a developer temperature of 30 ° C., and obtaining the unexposed photosensitive layer coating elution time. The results shown in Table 5 were obtained. In Examples 1 to 7, the development time hardly changed before and after storage, whereas in Comparative Example 5, the developability was significantly lowered. In other comparative examples, although the change in developability was observed, it was slight. With respect to sensitivity, using the PT-R4000, exposure is performed by changing the exposure amount on the plate surface in the range of 20 mJ / cm ² of 150 mJ / cm ² at 10 mJ / cm ² units, developing of 30 ° C. Evaluation was performed by determining the minimum exposure amount at which an image was formed when development was performed at a temperature for 30 seconds. The results are summarized in Table 6. In Examples 1 to 7, no change in sensitivity was observed before and after storage, but in Comparative Example 5, no image was formed even when the exposure amount was 150 mJ / cm ² , and a significant decrease in sensitivity occurred. I understood that.

  According to the present invention, a photosensitive composition having excellent storage stability, high image quality and high sensitivity can be obtained. 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 using a light source such as a near infrared laser emitting near 830 nm. 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.

Claims (4)

In a photopolymerizable composition having a photopolymerization initiator, an ethylenically unsaturated double bond compound, and a polymer binder, the photopolymerization initiator has two or more organic boron anions in the molecule, and a general formula A photopolymerizable composition comprising an organic boron salt forming a salt with a counter cation having a structure represented by 1.

In the general formula 1, R ₁ and R ₂ each represents an optionally substituted alkyl group. L ₁ represents any divalent linking group.   The photopolymerizable composition according to claim 1, wherein the photopolymerizable composition contains a dye having absorption in a range of 700 to 900 nm.   The photopolymerizable composition according to claim 1 or 2, wherein the photopolymerizable composition contains a polymer having a phenyl group in which a vinyl group is substituted on a side chain.   A photosensitive lithographic printing plate material using the photopolymerizable composition according to any one of claims 1 to 3.