JPH08220766A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE: To obtain a planographic printing plate excellent in ink depositing property and to provide such a photosensitive planographic printing plate that can be developed with a water-alkali liquid and shows no deterioration in qualities (such as reduction of sensitivity or failures) when the plate is stored at high humidity. CONSTITUTION: This photosensitive planographic printing plate has a photosensitive layer formed by applying a photopolymerizable photosensitive compsn. and a protective layer formed on the photosensitive layer. The protective layer contains the following component (A) or (B). Otherwise is photosensitive planographic printing plate has a protective layer containing the following (A) or (B) formed on a photosensitive layer. This photosensitive layer is formed by applying a photopolymerizable photosensitive compsn. containing a latex (a latex containing a polymer having quaternary nitrogen atoms in the side chains as the dispersoid) which can be dispersed in an org. solvent. (A) A compd. having long-chain alkyl groups of >=3 carbon number (e.g. CH3 -(CH2 )n -COOH). (B) Fluorine-based surfactant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive lithographic printing plate having a photopolymerizable photosensitive layer, and more particularly to a photosensitive lithographic printing plate developable with an aqueous alkaline solution.

[0002]

2. Description of the Related Art Conventionally, various photopolymerizable compositions which can be developed with an aqueous alkaline solution and which are applied to a photosensitive layer of a photosensitive lithographic printing plate have been proposed.

JP-B-46-42450 and JP-A-50-14162 use water-soluble photopolymerization initiators and ethylenically unsaturated compounds, which are uniformly dissolved in a water-soluble polymer. Polymerizable compositions are disclosed. But,
A photopolymerizable composition using a water-soluble one as a photopolymerization initiator or an ethylenically unsaturated compound has a photosensitive layer composed of the photopolymerizable composition as compared with a photopolymerizable composition using an oil-soluble one. Insufficient resistance (hereinafter referred to as "water resistance") to quality deterioration (sensitivity reduction, failure occurrence, etc.) when the photosensitive lithographic printing plate has a high humidity is stored, and the water-soluble polymer is used to receive ink. As an image, there is a problem that lipophilicity is insufficient and ink receptivity is poor.

JP-A-54-9585 proposes a photopolymerizable composition comprising a water-dispersible latex, a water-dispersible oligomer and a photopolymerization initiator. By using the water-dispersible latex, water resistance is improved. However, the lipophilicity is not sufficient, and there is a problem in ink receptivity when used by dispersing in water using a water-soluble photopolymerization initiator and an ethylenically unsaturated compound.

The present inventors have found that a photosensitive layer obtained from a photopolymerizable composition containing an oil-soluble ethylenically unsaturated compound, an organic solvent-dispersible water-insoluble particulate dispersion and an oil-soluble photopolymerization initiator is water-soluble. The inventors have found that it can be developed in a short time and proposed it (JP-A-58-174402 and JP-A-5-249675). However, the photosensitive lithographic printing plate having a photosensitive layer formed of the above photopolymerizable composition has room for improvement in ink receptivity and water resistance.

[0006]

Therefore, an object of the present invention is to provide an aqueous alkaline liquid which is capable of obtaining a lithographic printing plate excellent in ink receptivity and excellent in water resistance and storability of a photosensitive lithographic printing plate. It is to provide a photosensitive lithographic printing plate which can be developed by (1) and a photosensitive composition suitable as a photosensitive composition of the photosensitive lithographic printing plate.

[0007]

The constitution of the present invention for achieving the above-mentioned object of the present invention is as follows.

A photosensitive lithographic printing plate having a protective layer containing the following (A) or (B) on a photosensitive layer formed by coating a photopolymerizable photosensitive composition.

(A) Compound having a long-chain alkyl group having 3 or more carbon atoms (B) Fluorine-based surfactant Photosensitized by coating a photopolymerizable photosensitive composition containing a latex dispersible in an organic solvent. A photosensitive lithographic printing plate comprising a protective layer containing the following (A) or (B) on the layer.

(A) Compound having a long-chain alkyl group having 3 or more carbon atoms (B) Fluorine-based surfactant The present invention is described in detail below.

The photosensitive layer in the invention according to claim 1 is a photopolymerizable photosensitive layer containing at least a polymerizable compound and a photopolymerization initiator, and a known photosensitive layer can be applied. The photosensitive layer of the invention according to claim 2 is a photosensitive layer comprising the photopolymerizable photosensitive composition used for forming the photosensitive layer and a latex dispersible in an organic solvent.

In the invention according to claim 1 or 2, the photopolymerizable photosensitive composition contains a polymerizable compound and a photopolymerization initiator. An ethylenically unsaturated compound capable of addition polymerization can be used as the polymerizable compound. The ethylenically unsaturated compounds include monomers, prepolymers, that is, dimers, trimers, tetramers and oligomers (polymers or polycondensates having a molecular weight of 10,000 or less), their mixtures and copolymers thereof. Include.

As the above-mentioned ethylenically unsaturated compound, acrylic acid esters of polyhydric alcohols and methacrylic acid esters are preferable, and ethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, trimethylolpropane, pentaerythritol, neopentyl glycol are preferred. Examples thereof include acrylic acid and methacrylic acid ester.

Also, acrylic acid or methacrylic acid ester modified and derived from bisphenol A, for example, a reaction product of bisphenol A-epichlorohydrin type epoxy resin prepolymer and acrylic acid or methacrylic acid, an alkylene oxide adduct of bisphenol A. Alternatively, acrylic acid, methacrylic acid ester or the like of the hydrogenated product may be used.

In addition to these ester systems, methylenebisacrylamide, methylenebismethacrylamide and bisacryl or bismethacrylamide of diamines such as ethylenediamine, propylenediamine, butylenediamine and pentamethylenediamine are also useful.

Further, a reaction product of diol monoacrylate or diol monomethacrylate and diisocyanate, triacrylic formal or triallyl cyanurate is also suitable.

In addition to these monomeric compounds, a linear polymer compound having an acryloyloxy group or a methacryloyloxy group in its side chain, for example, a ring-opening copolymer of glycidyl methacrylate or a vinyl copolymer of glycidyl methacrylate. Acrylic acid and methacrylic acid addition reaction products can also be used.

As the ethylenically unsaturated compound, a water-soluble compound can be used, but a water-insoluble compound is preferable from the viewpoint of photosensitivity and water resistance of an image, and pentaerythritol tetraacrylate and triethyl acrylate are particularly preferable in terms of photosensitivity. Methylolpropane triacrylate is preferred.

As the photopolymerization initiator, a generally known compound effective for use in combination with the ethylenically unsaturated compound can be used, and examples thereof include the following compounds, but are not limited thereto.

Specific examples thereof include acyloin; benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether and other acyloin derivatives; decyl bromide,
Decyl chloride, decylamine and the like; ketones such as benzophenone, acetone phenone, benzyl and benzoylcyclobutanone; Michler's ketone, diethoxyacetone and substituted benzophenones such as halogenated aceto and benzophenone; thioxanthone, chlorothioxanthone, isopropylthioxanthone, diisopropylthioxanthone, methylthioxanthone. Derivatives such as thioxanthone derivatives, quinones and benzoquinones, polynuclear cyclic quinones such as anthraquinone and phenanthrenequinone; substituted polynuclear cyclic quinones such as chloranthraquinone, methylanthraquinone, octamethylanthraquinone, naphthoquinone, dichloronaphthoquinone; halogenated aliphatic, Alicyclic and aromatic hydrocarbons and mixtures thereof, provided that halogen is chlorine, bromine, fluorine, iodine And, for example, mono- and polychlorobenzene, mono- and polybromobenzene, mono- and polychloroxylene, mono- and polybromoxylene, dichloromaleic anhydride, 1- (chloro-2-methyl) naphthalene, 2,4 -Dimethylbenzene morphonyl chloride, 1-bromo-3- (m-phenoxyphenoxy) benzene, 2-bromoethyl methyl ether, chlorendeinic anhydride and its corresponding ester, chloromethylnaphthyl chloride, chloromethylnaphthalene, bromomethylphenanthrene, di Iodomethylanthracene, hexachlorocyclopentadiene, hexachlorobenzene, octachlorocyclopentene and their compounds, lophine dimer and N-methyl-2
-Benzoylmethylene-β-naphthothiazole, N-ethyl-
Heterocyclic compounds typified by 2- (2-thenoyl) methylene-β-naphthothiazole can be mentioned.

Examples of the photopolymerization initiator include "Photopolymer Technology" (Nikkan Kogyo Shimbun, 1988) No. 26
Representative compounds are disclosed on pages 50 to 113 and 113 to 123, for example 3,3 ′, 4,4′-tetrakis (t-
Butyloxycarbonyl) benzophenone, imidazole dimer, 9,10-dibromoanthracene, 2-naphthalenesulfonyl chloride, benzoyl peroxide, photopolymerization initiators such as onium salts are described, and any of these are included in the present invention. Can be used. Also, Japanese Patent Application No. 4-177480,
It is preferable to contain an initiator as conventionally reported as described in JP-A-58-174402, JP-A-58-174939 and JP-A-5-249675.

Further, as a photopolymerization initiator, Japanese Examined Patent Publication No. 59-42684
Coumarin derivatives and organic peroxides described in JP-B Nos. 6-76444 and 5-85562 can be preferably used. Examples of coumarin derivatives include 3- (2′-
Oxadiazoyl-5'-phenyl) -7-diethylaminocoumarin, 3-cyanocoumarin, 3-cyano-6-methoxycoumarin, 3-acetylcoumarin, 3-acetyl-7-ethoxycoumarin, 3-cyclohexylcarbonylcoumarin, 3-cyclopentyl Carbonyl-7-methoxycoumarin, 3-ethynylcarbonylcoumarin, 3-propenyl-7-ethoxycoumarin, 3-methoxycarbonylcoumarin, 3-ethoxycarbonyl-6-methoxycoumarin, 3-benzoylcoumarin, 3
-Benzoyl-7-methoxycoumarin, 3-benzoyl-5,7-
Dimethoxycoumarin, 7-methoxy-3- (p-nitrobenzoyl) coumarin, 3-benzoyl-7-hydroxycoumarin, 3-
Phenoxycarbonylcoumarin, 3- (2-ethylphenoxy) carbonylcoumarin, 3- (5,7-diethoxy-3-coumarinoyl) -1-methylpyridinium tetrafluoroborate, 3- (7-methoxy-3-coumarinoyl) -1 -Methylpyridinium hexafluforophosphate, N- (7-methoxy-3-coumarinoylmethyl) pyridinium bromide, 3,3'-carbonylbis- (7-dimethylaminocoumarin), 3,3'-carbonylbis- (7 -Diethylaminocoumarin), 7-diethylamino-3,3'-carbonylbiscoumarin, 7-diethylamino-5 ', 7'-dimethoxy-3,3'-carbonylbiscoumarin, 9- (7-diethylamino-3-coumarinoyl) -1,2,4,5-
Tetrahydro-3H, 6H, 10H [I] benzopyrano [9,9a, 1-g
h] quinolazin-10-one, 3,3′-carbonylbis- (7-methoxycoumarin), 3,3′-carbonylbis- (5,7-diisopropoxy) coumarin, 3-carboxycoumarin, 3-carboxy -7-methoxycoumarin, 7-methoxy-3-phenylsulfonylcoumarin, 7-methoxy-3-phenylsulfinylcoumarin and the like can be mentioned.

Among them, 3,3'-carbonylbis- (7-dimethylaminocoumarin), 3,3'-carbonylbis- (7-diethylaminocoumarin), 7-diethylamino-5 having an absorption maximum at 440 to 500 nm. ′, 7′-Dimethoxy-3,3′-carbonylbiscoumarin, 9- (7-diethylamino-3-coumarinoyl) -1,2,4,5-tetrahydro-3H, 6H, 10H [I] benzopyrano [9, 9a, 1-gh] quinolazin-10-one is preferred.

The compounds having these coumarin skeletons are
Both can be easily synthesized by the methods described in the literature. For example, Chemical R for Onoganocoumarin
eviews, 36 , 1 (1945) and Agra Univ. J, Research, 4 , 345 (1
955) and for bis compounds J. Chem. Eng. Data, 12 , 624 (1967) and Tetrahedro.
n, 38 , 1203 (1982) and the like.

The organic peroxide is an organic peroxide having one or more oxygen-oxygen mixed bonds in the molecule, and specific examples thereof include methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide and cyclohexanone peroxide. , Methylcyclohexanone peroxide, ketone peroxides such as 3,3,5-trimethylcyclohexanone peroxide, acetyl peroxide, propionyl peroxide, isobutyryl peroxide, octanoyl peroxide, 3,5,
5-Trimethylhexanoyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diacyl peroxides such as acetylcyclohexanesulfonyl peroxide, tert -Butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-methane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl Hydroperoxides such as hydroperoxide, di-tert-butyl peroxide, tert-butyl cumyl peroxide, 1,3-
Bis (tert-butylperoxyisopropyl) benzene,
1,4-bis (tert-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (tert-butyl) Peroxy) hexane-3 and other dialkyl peroxides, 1,1-bis
-tert-Butylperoxy-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, 2,2-bis (tert-butylperoxy) butane, etc. Oxyketals, tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-
Butyl peroxy octoate, tert-butyl peroxy pivalate, tert-butyl peroxy neodecanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxybenzoate, di-tert
-Butyl peroxyphthalate, di-tert-butyl peroxyisophthalate, tert-butyl peroxylaurate, alkyl peresters such as 2,5-dimethyl-2,5-dibenzoylperoxyhexane, di-2- Ethylhexyl peroxydicarbonate, Di-isopropyl peroxydicarbonate, Di-sec-butyl peroxycarbonate, Di-n-propyl peroxydicarbonate, Di-
Methoxyisopropyl peroxydicarbonate, di-3
-Methoxybutyl peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, bis- (4-tert-
Butylcyclohexyl) peroxydicarbonate, ter
Peroxycarbonates such as t-butylperoxyisopropyl carbonate and water-soluble peroxides typified by succinic acid peroxide can be mentioned.

As the photopolymerization initiator, a water-soluble one can be used, but a water-insoluble one is preferable from the viewpoint of photosensitivity and water resistance. The preferable composition ratio range of the polymerizable compound and the photopolymerization initiator in the photopolymerizable photosensitive composition of the invention according to claim 1 is 0.01 to 50% by weight of the polymerizable compound and 0.01 to 20% by weight of the photopolymerization initiator. is there.

If desired, various additives may be added to the photopolymerizable photosensitive composition of the invention according to claim 1. For example, an appropriate amount of hydroquinone and its similar compounds can be added as a thermal polymerization inhibitor that prevents thermal polymerization during storage and storage. In addition, additives such as a plasticizer, a development accelerator, an adhesion improver, a polymer as a binder, and a matting agent for roughening the surface of the photosensitive layer can be added. Further, the photopolymerizable photosensitive composition may contain the compound (A) and the surfactant (B).

In the invention according to claim 1 or 2, the photopolymerizable photosensitive composition may contain a binder which is usually used, and the photopolymerizable photosensitive composition contains a lipophilic polymer as a binder. It is preferable to include a compound. A preferred lipophilic polymer compound has an acid value of 10 to 25.
In the range of 0, for example polyamide, polyether, polyester, polycarbonate, polystyrene,
Examples thereof include polyurethane, polyvinyl chloride and copolymers thereof, polyvinyl butyral resin, polyvinyl formal resin, shellac, epoxy resin, phenol resin, acrylic resin and the like.

Among these, copolymers of the monomers shown in the following (1) to (16) are preferably used.

(1) A monomer having an aromatic hydroxyl group, such as N- (4-hydroxyphenyl) acrylamide, N- (4-
(Hydroxyphenyl) methacrylamide, o-hydroxystyrene, p-hydroxystyrene, m-hydroxystyrene, o-hydroxyphenyl acrylate, p-hydroxyphenyl acrylate, m-hydroxyphenyl acrylate, etc.

(2) Monomers having aliphatic hydroxyl groups, such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, N-methylol acrylamide, N-
Methylol methacrylamide, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl acrylate, 5-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, 6-
Hydroxyhexyl methacrylate, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide, hydroxyethyl vinyl ether and the like.

(3) Monomers having an aminosulfonyl group, for example, m-aminosulfonylphenyl methacrylate, p-aminosulfonylphenyl methacrylate, m-aminosulfonylphenyl acrylate, p-aminosulfonylphenyl acrylate, N- (p-aminosulfonylphenyl) ) Methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like.

(4) Monomers having unsaturated sulfonamides such as N- (p-toluenesulfonyl) acrylamide, N- (p-toluenesulfonyl) methacrylamide and the like.

(5) α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and itaconic anhydride.

(6) Substituted or unsubstituted alkyl acrylates such as methyl acrylate, ethyl acrylate,
Propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate, benzyl acrylate, cyclohexyl acrylate, acrylic acid -2-chloroethyl, N, N-dimethylaminoethyl acrylate, glycidyl acrylate, etc.

(7) Substituted or unsubstituted alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate. , Decyl methacrylate, undecyl methacrylate, dodecyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, 2-chloroethyl methacrylate,
N, N-dimethylaminoethyl methacrylate, glycidyl methacrylate, etc.

(8) Acrylamide or methacrylamide, such as acrylamide, methacrylamide,
N-ethyl acrylamide, N-hexyl acrylamide,
N-cyclohexylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N
-Phenylacrylamide etc.

(9) Monomers containing fluorinated alkyl groups such as trifluoroethyl acrylate, trifluoroethyl methacrylate, tetrafluoropropyl acrylate, tetrafluoropropyl methacrylate,
Hexafluoropropyl methacrylate, octafluoropentyl acrylate, octafluoropentyl methacrylate, heptadecafluorodecyl acrylate,
Heptadecafluorodecyl methacrylate, N-butyl-N
-(2-acryloxyethyl) heptadecafluorooctyl sulfonamide and the like.

(10) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether and phenyl vinyl ether.

(11) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.

(12) Styrenes such as styrene, methylstyrene and chloromethylstyrene.

(13) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone and phenyl vinyl ketone.

(14) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.

(15) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine and the like.

(16) Cyano group-containing monomers such as acrylonitrile, methacrylonitrile, 2-pentenenitrile, 2-methyl-3-butenenitrile, 2-cyanoethyl acrylate, o-cyanostyrene, m-cyanostyrene, p-
Cyanostyrene etc.

Further, a monomer copolymerizable with the above-mentioned monomer may be copolymerized. Further, a copolymer obtained by copolymerizing the above-mentioned monomers is also modified, for example, with glycidyl acrylate, glycidyl methacrylate, etc., but is not limited thereto.

More specifically, among the monomers listed in the above monomer groups (1) and (2), a copolymer having a hydroxyl group, which is obtained by copolymerizing at least one monomer with another monomer, Among the monomers listed in the monomer group (3), a copolymer having an aminosulfonyl group, which is obtained by copolymerizing at least one monomer with another monomer, is preferable.

Among these, as a more preferable monomer composition of the copolymer, 1 to 50 mol% of a monomer selected from the above monomer groups (1), (2) and (3), and a monomer group (5) 0 to 20 mol% of α, β-unsaturated carboxylic acid monomer selected from the above, 5 to 40 mol% of cyano group-containing monomer selected from the monomer (16), and monomer groups (6) and (7) Acrylic ester and / or methacrylic acid ester monomer selected from among 25 to 60
Examples thereof include those copolymerized in the range of mol%, and those in which, in addition to these monomers, any monomer selected from other monomer groups can be copolymerized as necessary can also be preferably used.

The above monomer groups are not limited to the monomers given as specific examples. The molecular weight of the above copolymer is limited by gel permeation chromatography (GPC). The weight average is preferably 10,000 to 200,000, but is not limited thereto.

Further, as another suitably used polymer compound, polyurethane is alkali-solubilized in JP-B-54-1.
9773, JP-A-57-94747, 60-182437, 62-5824
No. 2, No. 62-12345, No. 62-123453, No. 63-113450,
The polymer compounds described in JP-A No. 2-146042 are also useful.

The lipophilic polymer compound contained in the photopolymerizable photosensitive composition used in the photosensitive layer of the photosensitive lithographic printing plate of the present invention is preferably 0.01% in the solid content of the photosensitive composition.
˜70 wt%, more preferably 0.01 to 50 wt%.

If desired, any resin such as polyvinyl butyral resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, novolac resin or natural resin may be added.

The latex dispersible in the organic solvent contained in the photopolymerizable photosensitive composition according to the second aspect of the invention is stable for several hours or more without dissolving, coagulating or precipitating with the desired organic solvent as a dispersion medium. It is a dispersion system that can maintain a stable state. The latex useful in the present invention is not particularly limited in the type of dispersoid as long as it does not dissolve, aggregate or precipitate in a predetermined organic solvent. The latex may be used alone or in combination of two or more.

Examples of the latex dispersoid include polyacrylic acid ester or its copolymer, polyacrylonitrile or its copolymer, polystyrene or its copolymer, polyethylene or its copolymer, polyvinyl chloride or its copolymer, polyvinylidene chloride or its copolymer. , Polyvinyl acetate or its copolymer,
Resol resin or its copolymer, ionomer resin,
Examples thereof include polymethylmethacrylate or a copolymer thereof and polybutadiene or a copolymer thereof.

The polymer compound which is preferably used in the invention and which forms the dispersoid of the latex dispersible in the organic solvent preferably has a quaternary nitrogen atom in the molecule, whereby the dispersibility in water is improved. In addition, a physical bond with the polymer of the ethylenically unsaturated compound occurs. The quaternary nitrogen atom is preferably contained in the side chain of the polymer molecule.

Typical examples of the monomer units constituting such a polymer include those represented by the following general formulas [1] to [5].

[0057]

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[0058]

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In the general formulas [1] to [5], X ⁻ represents an anion. That is, halogen ion, sulfate ion, phosphate ion, sulfonate ion, acetate ion, other BF ₄ containing fluorine _{^{-, PF 6 -, SiF 6}} 2-, SbF 6 -, include anions such as BeF ₄ ^2- Be done.

The Rs attached to N ⁺ may be the same or different and each R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (eg, methyl, ethyl, propyl, isobutyl, pentyl, hexyl). , Heptyl, decyl groups), alkenyl groups (eg propenyl, butynyl groups), or aryl groups having 6 to 20 carbon atoms (eg phenyl, naphthyl groups), aralkyl groups (eg benzyl, Phenethyl, naphthyl, methyl groups) or alkaryl groups (eg, tolyl, xylyl groups). Further, those having a polymerizable unsaturated ethylene group are also preferable. This is because if a polymerizable group is contained in the molecule, it polymerizes with the above-mentioned ethylenically unsaturated compound during photopolymerization to form a chemical bond. Z represents a group of non-metal atoms necessary for forming an unsaturated heterocycle, and is preferably an imidazole, pyridine, piperidine, pyrrole or morpholine ring. n represents an integer.

A latex polymer having a cationic group and having a monomer unit represented by the above general formulas [1] to [5] has no polar group because it has a C—C bond in its main chain and is hydrophobic. Therefore, it contributes to the hydrophobicity of the photosensitive layer when it is formed. When the latex polymer is, for example, a water-based latex polymer, it may have a water-soluble group to the extent that it can be dispersed in water, so that a relatively large number of hydrophobic groups can be introduced into the polymer molecule, resulting in a decrease in hydrophilicity. This is advantageous in that it can be used and that the dispersion liquid containing it has a low viscosity relative to the resin concentration and therefore has good coatability when forming the photosensitive layer, and that the dried film can be formed into a thick film. In order to adjust the water solubility by introducing a hydrophobic group into this terax polymer, it is sufficient to copolymerize a non-cationic monomer with the above-mentioned cationic monomer. Examples of this non-cationic monomer include acrylic acid ester and methacrylic acid. Ester, styrene, alkylene, vinyl acetate, acrylonitrile and the like can be mentioned. This latex polymer is preferably crosslinked with a monomer having two or more unsaturated groups such as divinylbenzene and dimethacrylate, and is preferably produced by emulsion polymerization. This reduces the hydrophilicity of the monomer,
This is because emulsion polymerization can be effectively performed, and as a result, it contributes to the improvement of film strength.

In order to produce a copolymer of the above-mentioned cationic monomer and non-cationic monomer, 5 to 5 cationic monomers are contained in the above latex polymer having a cationic group.
It is preferably contained in an amount of 95% by weight, more preferably 25 to 65.
% By weight. Further, the non-cationic monomer is preferably contained in an amount of 5 to 95%, and the crosslinking monomer such as divinylbenzene is preferably contained in an amount of 0.1 to 8% by weight.

As a synthesis example of the above-mentioned latex polymer having a cationic group, vinylbenzyl chloride is emulsion-polymerized with another monomer as described in Examples of JP-A-51-73440, and then, A method of quaternizing with a tertiary amine can be adopted. Another preferred synthetic method is JP-A-55-2.
This is the method described in Japanese Patent No. 2766. Another preferable synthetic method is the method described in JP-A-56-17352.

The latex polymer having a cationic group used in the present invention has a quaternary nitrogen atom in the cationic group in the composition, and has an amine, particularly a tertiary amine, in its molecule. As a result of being dispersed in an aqueous solvent 4
It also includes the case where it is a cationic group having a primary nitrogen atom.

The particle size of the latex weight is 10 to 200 n.
m is preferable, and when it is smaller than 10 nm, it is difficult to manufacture and it is not practical. On the other hand, when it is larger than 200 nm, the resolution of the image is deteriorated when the image portion after the exposure of the photosensitive layer is formed.

Specific examples of the polymer having a cationic group of the present invention include the compounds shown below. In the parentheses, the molar ratio is shown.

[0067]

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[0068]

[Chemical 4]

[0069]

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[0070]

[Chemical 6]

[0071]

[Chemical 7]

[0072]

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[0073]

[Chemical 9]

[0074]

[Chemical 10]

As the latex dispersible in the organic solvent used in the invention according to claim 2, a water-insoluble particulate dispersion described in JP-B-2-15056 and an organic dispersion described in JP-A-58-174402. A solvent-dispersible water-insoluble particulate dispersion and a latex polymer having a cationic group described in JP-A-60-3623 can be preferably used.

The preferable composition ratio range of the polymerizable compound, the photopolymerization initiator and the latex dispersible in the organic solvent in the photosensitive composition of the invention according to claim 2 is as follows.
0.01 to 50% by weight, 0.01 to 20% by weight of a photopolymerization initiator, and 0.01 to 50% by weight of a latex dispersible in an organic solvent.

If desired, various additives can be added to the photopolymerizable photosensitive composition of the invention according to claim 2. For example, an appropriate amount of hydroquinone and its similar compounds can be added as a thermal polymerization inhibitor that prevents thermal polymerization during storage and storage. In addition, additives such as a plasticizer, a development accelerator, an adhesion improver, another polymer as a binder, and a matting agent for roughening the surface of the photosensitive layer can be added. Further, the photopolymerizable photosensitive composition may contain the compound (A) and the surfactant (B).

In order to produce the above-mentioned photopolymerizable photosensitive composition, the above-mentioned respective components may be mixed by stirring by an appropriate means.
The photopolymerizable photosensitive composition is dispersed or dissolved in an appropriate dispersion medium or solvent, coated on an appropriate support as a plate material for a lithographic printing plate, and dried to form a photosensitive layer. This dispersion medium or solvent may be only water, and in this case, there is no problem of pollution, but it is miscible with water in order to improve the wettability of the photosensitive composition and the support during coating and the drying property during drying. An organic solvent can be supplementarily used together. Examples of such substances include methanol, ethanol, methyl cellosolve, ethyl cellosolve, acetone, halogenated hydrocarbons, ethyl acetate and the like.

As the support of the photosensitive lithographic printing plate, a metal plate of aluminum, iron, copper, or an alloy thereof,
Examples include paper supports, particularly synthetic paper (polypropylene, polyethylene laminated paper, etc.), plastic supports (eg, cellulose acetate, polyethylene terephthalate, polypropylene, polystyrene, vinylidene chloride, etc.).

Such a support is preferably surface-treated electrically, chemically or mechanically for the purpose of improving the adhesion to the photosensitive layer. Further, an undercoat layer may be provided to improve the adhesiveness. Furthermore, in order to make the surface of the photosensitive layer formed as described above less slippery, a layer made of a matting agent may be provided, and in the case of a photosensitive image forming material using a flexible support, An anti-curl layer for preventing curling may be provided on the surface opposite to the photosensitive layer.

To form a photosensitive layer, a coating solution containing a photopolymerizable photosensitive composition is applied to a support by a wire bar coating method, a spin coating method, a brush coating method, a doctor blade coating method or a hopper coating method. Typical application means are used,
After being applied by these means, it is dried by an appropriate means. The thickness of the photosensitive layer is preferably 1.0 to 2.5 μm, more preferably 1.2 to 2.0 μm.

The protective layer provided on the photosensitive layer of the photosensitive lithographic printing plate of the invention according to claim 1 or 2 preferably uses a resin as a binder and contains a compound having a long chain alkyl group having 3 or more carbon atoms and / or Alternatively, it is a layer containing a fluorine-based surfactant.

Examples of the resin used as the binder include gum arabic, glue, gelatin, celluloses (eg viscose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose etc.), starches (eg soluble starch, Modified starch etc.), polyvinyl alcohol, polyethylene oxide, polyacrylic acid, polyacrylamide, polyvinyl methyl ether, polyvinyl pyrrolidone, polyamide, natural polysaccharides and the like. Preferably polyvinyl alcohol,
Polyvinylpyrrolidone and natural polysaccharides. Two or more of these may be used in combination. As the material for the protective layer, those described in JP-A-58-174402 can be applied. The thickness of the protective layer is preferably 2.0 ~ 4.0 μm,
More preferably, it is 2.5 to 3.5 μm.

The compound having a long-chain alkyl group having 3 or more carbon atoms includes a compound having an aromatic substituent and / or an alcoholic --OH group, and a compound having a long-chain alkyl group introduced into novolak. . The compound having a long-chain alkyl group having 3 or more carbon atoms is preferably an aliphatic monocarboxylic acid, more preferably a fatty acid having 3 to 25 carbon atoms, and further preferably a fatty acid having 10 to 25 carbon atoms. Is. As such a fatty acid, a fatty acid monocarboxylic acid is preferably used. When the number of carbon atoms is less than 10, it is inferior in residual film, residual dye and underdeveloping property.
If it is more than 25, the solubility in the solvent is poor and the coatability may be deteriorated.

Specific examples of the compound having a long-chain alkyl group having 3 or more carbon atoms are shown below.

[0086]

[Chemical 11]

The content of the compound having a long-chain alkyl group having 3 or more carbon atoms in the photopolymerizable composition of the present invention is preferably 0.001 to 5%, more preferably 0.01 to 3%.

Examples of the fluorinated surfactant include the following compounds.

[0089]

[Chemical 12]

Commercially available products may be used as the fluorine-containing surfactant. For example, Surflon "S-38" and "S-38" may be used.
2 "," SC-101 "," SC-102 "," SC-103 ",
"SC-104" (both manufactured by Asahi Glass Co., Ltd.), Florard "FC-430", "FC-431", "FC-173" (both manufactured by Fluorochemical-Sumitomo 3M), F-top "EF352", "EF301", "EF303" (all manufactured by Shin-Akita Kasei Co., Ltd.), Schvego Fluor "8035", "80"
36 "(all manufactured by Schvegman)," BM1000 ",
Examples thereof include "BM1100" (all manufactured by BM Himmy), Megafac "F-171", "F-177" (all manufactured by Dainippon Ink and Chemicals, Inc.) and the like. The fluorine content of the fluorine-based surfactant in the present invention is 0.
It is from 05 to 2%, preferably from 0.1 to 1%. Further, the addition amount to the protective layer is preferably 0.001 to 10%. The above-mentioned fluorine-based surfactants can be used alone or in combination of two or more, and can also be used in combination with other surfactants.
The protective layer of the invention according to claim 1 or 2 may contain other additives (for example, antioxidants). Examples of means for providing the protective layer on the photosensitive layer of the photosensitive lithographic printing plate of the present invention include a coating method and a laminating method.

The photosensitive lithographic printing plate of the invention according to claim 1 or 2 (hereinafter referred to as "the present invention") prepared as described above is first imagewise exposed to actinic rays. Here, as the actinic ray, any one can be used as long as it is sensitive to the photopolymerization initiator contained in the photopolymerizable photosensitive composition, and examples thereof include a mercury lamp, a xenon lamp, and a laser. .

The exposed portion of the photosensitive layer of the imagewise exposed lithographic printing plate is removed by a developing solution containing an aqueous alkaline solution. Examples of the alkaline agent used in the developer (including the replenisher) of the photosensitive lithographic printing plate of the present invention include sodium silicate, potassium silicate, sodium hydroxide, lithium hydroxide, sodium triphosphate and diphosphorus. Inorganic alkaline agents such as sodium phosphate, potassium triphosphate, dibasic potassium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, etc. ,
Organic alkaline agents such as mono-, di- or triethanolamine and tetraalkylammonium hydroxide and organic ammonium silicates are useful. Of these, silicates are preferred, and alkali metal silicates are most preferred. Content of alkaline agent in developer is 0.05
It is preferably used in the range of 20 to 20% by weight, more preferably 0.1 to 10% by weight. Particularly preferred as the developer is an alkali metal salt having a silicate [SiO ₂ ] / alkali metal oxide [M ₂ O] ratio (provided that silicate [SiO ₂ ],
Alkali metal oxide [M ₂ O] indicates a molar concentration. ) Is 0.1
To 2.0, more preferably 0.3 to 1.5.

Additives such as an organic solvent and a water-soluble reducing agent can be added to the developer used for developing the photosensitive lithographic printing plate of the present invention.

As the organic solvent, those having a solubility in water at 20 ° C. of 10% by weight or less are preferable. Examples of such an organic solvent include ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate and ethylene. Carboxylic esters such as glycol monobutyl acetate, butyl lactate and butyl levulinate; ketones such as ethyl butyl ketone, methyl isobutyl ketone and cyclohexanone; ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene diglycol monophenyl ether, Alcohols such as benzyl alcohol, methylphenylcarbinol, n-amyl alcohol and methylamyl alcohol; alkyl-substituted aromatic hydrocarbons such as xylene; methylene dichloride, ethylene di Roraido, and the like halogenated hydrocarbons such as monochlorobenzene. One or more organic solvents may be used for this. Among these organic solvents, ethylene glycol monophenyl ether, ethylene glycol benzyl ether and benzyl alcohol are particularly preferable.

The water-soluble reducing agent includes organic and inorganic reducing agents. Examples of the organic reducing agent include phenol compounds such as hydroquinone, metol and methoxyquinone, amine compounds such as phenylenediamine and phenylhydrazine, and examples of the inorganic reducing agent include sodium sulfite, potassium sulfite, ammonium sulfite and hydrogen sulfite. Sodium, sulfites such as potassium bisulfite, sodium phosphite, potassium phosphite, sodium hydrogen phosphite, potassium hydrogen phosphite, sodium dihydrogen phosphite, phosphates such as dipotassium hydrogen phosphite ,
Although hydrazine, sodium thiosulfate, sodium dithionite, etc. can be mentioned, a reducing agent which is particularly effective in the present invention is sulfite. The meaning of water-solubility of the water-soluble reducing agent also includes alkali-solubility, and these water-soluble reducing agents are contained in the range of preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.

The following additives may be added to the developer used for developing the photosensitive lithographic printing plate of the present invention in order to further enhance the developing performance. For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, chelating agents such as EDTA and NTA described in JP-A-58-190952, and JP-A-59-121.
Complexes such as [C ₀ (NH ₃ ) ₆ ] Cl ₃ described in Japanese Patent No. 336, JP-A-55-95946
Polymers such as p-dimethylaminomethylpolystyrene quaternary compounds of methyl chloride, etc.
Ampholytic polyelectrolytes such as copolymers of vinylbenzyltrimethylammonium chloride and sodium acrylate described in 56-142528, reducing inorganic salts described in JP-A-57-192952, and chlorides described in JP-A-58-59444. Inorganic lithium compounds such as lithium, organic lithium compounds such as lithium benzoate described in JP-B-50-34442, S described in JP-A-59-75255
Examples thereof include organic metal surfactants containing i, Ti and the like, organic boron compounds described in JP-A-59-84241 and the like.

[0097]

EXAMPLES Examples of the present invention will now be described, but the embodiments of the present invention are not limited to these. In addition, in the following Examples and Comparative Examples, Examples 1 to 9 and Comparative Examples 1 to 9 relate to claim 1, and Examples 10 to 12 and Comparative Examples 10 to 12 relate to claim 2.

Preparation of support An aluminum plate having a thickness of 0.3 mm was electrolytically surface-roughened in an aqueous solution of hydrochloric acid, then anodized in an aqueous solution of sulfuric acid, and then hydrophilized using an aqueous solution of sodium silicate to support aluminum. The body was obtained and used as a support for the photosensitive lithographic printing plates of the following Examples and Comparative Examples.

Examples 1 to 9 and Comparative Examples 1 to 9 Photosensitive layer coating solutions and overcoat layer coating solutions having the following compositions were prepared.

Coating liquid for photosensitive layer 1 Dipentaerythritol tetraacrylate 5.0 g Phenolic hydroxyl group-containing acrylic copolymer (HyPMA / MAA / AN / EA / EMA (30/1/30/9/30), Mw = 50000) 5.0g 3,3'-carbonylbis (diethylaminocoumarin) 0.6g 3,3 ', 4,4'-tetrakis (t-butyldioxycarbonyl) benzophenone 0.8g 2-methoxyethanol 64.6g HyPMA: hydroxyphenyl methacrylate MAA: Methyl acetoacetate AN: Acrylonitrile EA: Ethyl acrylate EMA: Ethyl methacrylate Coating liquid for photosensitive layer 2 Dipentaerythritol tetraacrylate 5.0 g Acrylic copolymer (MAA / MAA (20/80) copolymer, Mw = 25000) 5.0g 3,3'-Carbonylbis (diethylaminocoumarin) 0.6g 3,3 ', 4,4'-Tetrakis (t-butyldioxycarbonyl) benzopheno 0.8 g 2-Methoxyethanol 64.6 g Coating liquid for photosensitive layer 3 Dipentaerythritol tetraacrylate 5.0 g Acrylic copolymer (MAA / CHMA (30/70) copolymer, Mw = 25000) 5.0 g 3,3'- Carbonyl bis (diethylaminocoumarin) 0.6g 3,3 ', 4,4'-tetrakis (t-butyldioxycarbonyl) benzophenone 0.8g 2-methoxyethanol 64.6g CHMA: Cyclohexyl methacrylate Overcoat layer coating solution 1 PVA GL05R ( A solution obtained by adding 3% of stearic acid to PVA to a 10% aqueous solution of Nippon Synthetic Chemical Industry Co., Ltd.

Coating solution for overcoat layer 2 PVA GL05R (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) in 10% aqueous solution, FluoroTenside FT248 (manufactured by Bayer C ₈ F ₁₇ N (C ₂ H ₅ ) ₄ ⁺ )
SO ₃ ^-) was added 3% to PVA solution.

[0102] stearic acid 10% aqueous solution of the overcoat layer coating solution 3 PVA GL05R (manufactured by Nippon Synthetic Chemical Industry Co.,) was added 3% to PVA, further fluoro Ten side FT248 (Bayer C ₈ F _{17 N (C 2 H 5) 4} + SO 3 -) was added 3% to PVA solution.

Coating Solution for Comparative Example Coating Solution 4 for Overcoat Layer 4 A 10% aqueous solution of PVA GL05R (Nippon Gosei Kagaku Co., Ltd.).

Coating solution for overcoat layer 5 A solution prepared by adding 3% of PVA to L-alanine in a 10% aqueous solution of PVA GL05R (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).

Coating solution for overcoat layer 6 A solution prepared by adding 3% of polyethylene glycol # 1000 to PVA to a 10% aqueous solution of PVA GL05R (Nippon Gosei Kagaku Co., Ltd.).

A combination of the photosensitive layer coating liquids 1 to 3 and the overcoat layer coating liquids 1 to 6 shown in Table 1 below is used to form the photosensitive layer coating liquid on the support using a wire bar after drying. The coating solution for the overcoat layer was applied to a thickness of 1.5 μm and dried, and the coating solution for the overcoat layer was further applied thereto with a wire bar so that the film thickness after drying was 3.0 μm and dried. Photosensitive lithographic printing plates of Comparative Examples 1 to 9 were prepared. These photosensitive lithographic printing plates were exposed with Ar ⁺ laser light (488 μm) at a scan speed of 9.8 m / s and a scan time (41 cm × 59 cm) for 9.7 min, and a cylindrical exposure machine was used for scanning. Further, for the exposed photosensitive lithographic printing plate, an automatic developing machine PSZ-
910 (manufactured by Konica Corporation) was used. Under the above conditions, the ink receptivity, water resistance and storability of the photosensitive lithographic printing plate were evaluated by the following methods. The results are shown in Table 1 below.

Developer 1 A Potassium silicate (Nippon Kagaku Kogyo KK, SiO ₂ = 26%, K ₂ O = 13.5%) 400 g Potassium hydroxide (50% aqueous solution) 195 g Water 11.5 l [SiO ₂ ] / [K ₂ O] = 1.2 Evaluation of ink receptivity Ink SPO-1 was applied to the planographic printing plate obtained by exposure and development.
(Manufactured by Konica Corp.) was placed and the formed small dots were observed with a magnifying glass.

◯: Small dots reproduced in the same manner as in a normal photosensitive lithographic printing plate.

Δ: The small dots were slightly rough.

X: Small dots are sharp and ink is not attached.

Evaluation of Water Resistance The photosensitive lithographic printing plate before development was stored at 40 ° C. and 80% relative humidity for 3 days (hereinafter referred to as “HT-3”), and the change in sensitivity due to this storage with respect to the same day sensitivity was measured. In addition, the degree of erosion of the photosensitive layer was visually evaluated. The evaluation criteria for the damage of the photosensitive layer are as follows.

◯: The photosensitive layer has no change from that before storage.

Δ: The visible image quality (color) of the photosensitive layer is slightly lowered.

X: White spots are formed on the photosensitive layer.

Evaluation of storability of the photosensitive lithographic printing plate The photosensitive lithographic printing plate before development was stored at 50 ° C. and 20% relative humidity for 5 days (hereinafter referred to as “DT-5”), and the sensitivity obtained by the above storage with respect to the same day sensitivity. The fluctuation was evaluated.

The sensitivity in the evaluation of the storability of the water-resistant and photosensitive lithographic printing plate was determined by the gray scale method.
Specifically, using light of a wavelength of 490 nm taken out from a filter using an ultra-high pressure mercury lamp, the photosensitive lithographic printing plate was irradiated with a gray scale in close contact, and then developed by the above method to obtain a cured image from the minimum exposure energy I asked.

[0117]

[Table 1]

From Table 1, according to the invention of claim 1,
It can be seen that a photosensitive lithographic printing plate having excellent ink receptivity, water resistance and storability of the photosensitive lithographic printing plate can be obtained.

Examples 10 to 12 and Comparative Examples 10 to 12 Coating liquid for photosensitive layer 4 3,3'-Carbonylbis (diethylaminocoumarin) 0.6 g 3,3 ', 4,4'-tetrakis (t-butyldioxy) Carbonyl) benzophenone 0.8 g Pentaerythritol triacrylate 5.0 g Latex 5.0 g dispersible in organic solvent

[0120]

[Chemical 13]

2-Methoxyethanol 64.6 g As the coating liquid for the overcoat layer, the coating liquids 1 to 6 for the overcoat layer were used.

The above-mentioned photosensitive layer coating liquid 4 and overcoat layer coating liquids 1 to 6 were combined in the same manner as in Example 1 by applying the photosensitive layer coating liquid in the same manner as in Example 1, and the overcoat was applied thereon. The coating liquid for the coating layer was applied to prepare the photosensitive lithographic printing plates of Examples 10-12 and Comparative Examples 10-12. With respect to these photosensitive lithographic printing plates, ink receptivity, water resistance and storability of the photosensitive lithographic printing plates were evaluated in the same manner as in Example 1. The results are shown in Table 2 below.

[0123]

[Table 2]

From Table 2, according to the invention of claim 2,
It can be seen that a photosensitive lithographic printing plate having excellent ink receptivity, water resistance and storability of the photosensitive lithographic printing plate can be obtained.

[0125]

INDUSTRIAL APPLICABILITY According to the present invention, a lithographic printing plate excellent in ink receptivity is obtained, and water resistance (deterioration in quality when the photosensitive lithographic printing plate is stored at high humidity (decrease in sensitivity, A photosensitive lithographic printing plate which has excellent resistance to damage to the photosensitive layer and can be developed with an aqueous alkaline solution is obtained.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideyuki Nakai 1 Konica Stock Company, Sakura-cho, Hino City, Tokyo

Claims (2)

[Claims] 1. A photosensitive lithographic printing plate having a protective layer containing the following (A) or (B) on a photosensitive layer formed by coating a photopolymerizable photosensitive composition. (A) Compound having a long-chain alkyl group having 3 or more carbon atoms (B) Fluorine-based surfactant 2. A protective layer containing (A) or (B) below is provided on a photosensitive layer formed by coating a photopolymerizable photosensitive composition containing a latex dispersible in an organic solvent. Photosensitive lithographic printing plate. (A) Compound having a long-chain alkyl group having 3 or more carbon atoms (B) Fluorine-based surfactant