JPH0277750A - Photosensitive planographic printing plate requiring no dampening water - Google Patents

Abstract

PURPOSE:To obtain a photosensitive planographic printing plate requiring no dampening water by laminating a silicone layer and a photosensitive layer contg. a polymer having polyorganosiloxane units in the side chain on a substrate. CONSTITUTION:Coated paper, an Al sheet or other substrate capable of withstanding the load of printing is coated with a layer of silicone based on polyorganosiloxane having prescribed repeating units in the principal chain and the silicone is cross-linked to form a silicone layer acting an ink repellent layer. The pref. viscosity of the silicone is 1-10,000 St at 25 deg.C. The thickness of the silicone layer is regulated to 2-50mum. A photosensitive layer having a great affinity for silicone and adhesive strength is laminated on the silicone layer with a polymer having polyorganosiloxane units in the side chain and an o-quinonediazido compd. such as o-quinonediazidosulfonic ester or carboxylic ester obtd. by chemically condensing an o-quinonediazidosulfonic acid or carboxylic acid deriv. with polycondensation resin consisting of phenols and aldehydes or ketones. The photosensitive layer is formed by applying a soln. of the components in a solvent such as methylcellosolve. An aq. Alkali soln. or a mixture of specified org. solvents is used as a developer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to positive-working and negative-working photosensitive lithographic printing plates that do not require dampening water and use a silicone layer as an ink repelling layer.

(Prior Art) Many photosensitive lithographic printing plates that do not require dampening water have been proposed, which are comprised of a substrate, a silicone layer provided on the substrate, and a photosensitive layer provided on the silicone layer.

In these known techniques, a positive type photosensitive lithographic printing plate that does not require dampening water and uses a photosensitive layer containing an orthoquinonediazide compound together with a novolac resin, an epoxy resin, an acrylic resin, etc. 3g3 Publication, Special Publication Sho Otsu/-673 Publication, Japanese Patent Publication Sho! ;b-2! i
It is described in the 7-ke θ publication. In addition, examples of negative-working photosensitive planographic printing plates that do not require dampening water and whose photosensitive layer is formed from a photopolymerizable composition, and negative-working photosensitive planographic printing plates that do not require dampening water using diazo resin are known. ing.

(Refer to Kosho Guar No. 236/publication) (Problems to be solved by the invention) However, the printing plates shown in these
In either case, a photosensitive layer having low affinity with silicone must be laminated on the silicone layer, which is difficult to manufacture. For example, Tokko Akira! ;3-/l73g3 discloses a method of manufacturing a photosensitive layer coated on a polyolefin film by pressing it onto a support provided with a silicone layer. However, it is extremely difficult to manufacture industrially using such a method.

In addition, since photosensitive layers with low affinity for silicone are laminated, there is a problem in that the adhesion between the two layers is insufficient, making it difficult to obtain good images.

For these reasons, there has been a desire for a photosensitive layer that has high affinity with silicone, can be easily coated onto a silicone layer, has adhesive strength at the interface, and has good ink adhesion.

(Means to Solve the Problem) The present inventors are conducting extensive research into a photosensitive layer that has a high affinity with silicone, can be easily coated on a silicone layer, and has adhesive strength at the interface. As a result of repeating
The present invention was achieved based on the knowledge that the above object can be achieved by incorporating a graft polymer having polyorganosiloxane units in side chains (branch polymers) in the photosensitive layer. That is, the gist of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water, in which a silicone layer and a photosensitive layer are provided in this order on a substrate, and the photosensitive layer has polyorganosiloxane units on its side. There are a number of photosensitive lithographic printing plates that do not require dampening water and are characterized by containing polymers in chains.

The present invention will be explained in detail below.

The photosensitive lithographic printing plate that does not require dampening water of the present invention has a silicone layer serving as an ink repelling layer and a photosensitive layer serving as an ink receiving layer on a substrate in this order.

The substrate is not particularly limited as long as it has the flexibility to be set in a normal lithographic printing machine and can withstand the load applied during printing. Examples include papers such as coated paper, metal plates such as aluminum plates, and plastic films such as polyethylene terephthalate. It is also useful to provide antihalation layers on these substrates.

In the present invention, the silicone layer serving as the ink repellent layer has, for example, as a main component a polyorganosiloxane having a repeating unit as shown in the following general formula (1) in the main chain,
It can be formed by coating this on a substrate and then crosslinking it.

→Si −0← ・・・・・・・ (1)■ Here, R1 and R2 are each a hydrogen atom, unsubstituted or substituted (for example, by a halogen atom, cyan group, amine group) carbon number/~10 arbitrarily selected from the alkyl group, alkenyl group, or phenyl group of
, fcz is preferably 60 or more methyl groups. The molecular weight is arbitrary, but the viscosity at 1.25℃ is /
~10,00'0 Stokes is preferred.

Crosslinking of organopolysiloxanes as described above can be achieved, for example, by using a polyorganosiloxane in which a hydroxyl group or a hydrolyzable group (for example, an acyloxy group, an alkoxy group, a ketoximate group, an amine group, an amide group, etc.) is bonded to the terminal silicon atom. and then crosslinked by a condensation reaction according to a conventional method. Particularly preferably used are polyorganosiloxanes having hydroxyl groups bonded to both ends, and specifically, for example, α, ω-
Dihydroxydimethylpolysiloxane is mentioned. Usually these polyorgans, γ-glycidoxyprobyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, methyltriacetoxysilane, vinyltris(methylethylketoxime)silane, methyltris(methylethylketoxime)silane etc.).

In this case, it is preferable to add a known metal catalyst, such as tetramethyl orthotitanate, as a catalyst. These catalysts are 0.0/~ based on the total weight of silicone.
S is used in an amount of % by weight, preferably in a range of 0.0λ to 0.0% by weight.

It is also useful to add an inorganic filler such as silica or calcium carbonate to the total weight by about 07 to 90 weight percent for the purpose of reinforcement.

To form a silicone layer, add each of the above ingredients.
It can be dissolved in aliphatic hydrocarbons such as cyclohexane, methylcyclohexane, n-hexane, n-hebutane, co-methylhexane, or a mixed solvent with a small amount of radobenzene, toluene, or xylene natonoaromatic hydrocarbons. Apply the silicone solution according to the usual method, and
A sufficiently cured non-adhesive silicone layer is formed by heat treatment at a temperature range of 0° C. to iso° C. for several minutes or more.

The thickness of the silicone layer is preferably 0.7 to 200 μm, preferably 7 to 100 μm, and more preferably 2 to 0 μm.

In the present invention, both positive type and negative type photosensitive layers can be used. Examples of orthoquinone diazide compounds that can be used in positive type photosensitive lithographic printing plates that do not require dampening water include polycondensation resins of phenols and aldehydes or ketones, and compounds represented by the following general formula (2) or (3). Examples include orthoquinonediazide sulfonic acid esters or carboxylic acid esters obtained by chemically condensing orthoquinonediazide sulfonic acid or carboxylic acid derivatives.

(In the formula, X is a group represented by -5O2Y or -COY, and Y means a group that can be removed during condensation of a halogen atom, alkali metal, etc.) As a specific example,
/, x-benzoquinonediazide (2)-xi-sulfonyl chloride, /, 2-benzoquinonediazide (2)-
Examples thereof include y-carbonyl chloride, /, 2-benzoquinonediazide (2)-s-sulfonyl chloride, /, 2-benzoquinonediazide (2)-s-carbonyl chloride, and the like. Specific examples of the compound represented by the above general formula (3) include /-1naphthoquinonediazide (2)-y-sulfonyl chloride, /,2-naphthoquinonediazide (2)
)-+-carbonyl chloride, /, ninaphthoquinone diazide (2) -5-sulfonyl chloride, /, λ-naphthoquinone diazide (2) -s-carbonyl chloride, and the like.

Examples of polycondensation resins of phenols and aldehydes or ketones include Tokko Sho 3-. 2g1I03, a polycondensate of pyrogallol and acetone, as described in JP-A-5S-763'l, a polycondensate of a mixture of pyrogallol and resorcin and acetone, 'I! ; Phenol formaldehyde novolak resin or metacresol formaldehyde novolak resin as described in Japanese Patent Publication No. 9A10, para-substituted phenol polymeric resin (e.g. Cresol/formalin resin,
Para-t-butylphenol/formalin resin, para-ethylphenol/formalin resin, parapropylphenol/formalin resin, barisoglobylphenol/
Formalin resin, para-n-butylphenol/formalin resin, paraoctylphenol/formalin resin, etc.) As described in Japanese Patent Publication No. Sho A2-60G07, phenols substituted with alkyl groups or phenyl groups having 3 to 1 carbon atoms. and phenol or its methyl substituted product or a mixture thereof in a molar ratio of /:9 to 9:/ and a polycondensed metal of formaldehyde (
Examples include polycondensates of the para-substituted phenols and phenol, para-cresol, metacresol, or ortho-cresol).

The esterification rate of the orthoquinonediazide group to the hydroxyl group of the polycondensation resin of phenols and aldehydes or ketones is preferably /3 to 100 molar, and more preferably 2 o-go molar. Ortho-naphthoquinone diazide sulfonic acid ester of hydroxybenzophenone (e.g., 2-naphthoquinone diazide (2)-s-sulfonic acid ester, hako-naphthoquinone diazide (2)-q-sulfonic acid ester, etc.)
etc.

This polyhydroxybenzophenone is a compound obtained by substituting at least one hydrogen atom of benzophenone with a hydroxyl group, such as dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, pentahydroxybenzophenone, octahydroxybenzophenone, or a derivative thereof (for example, Substituents of a halogen atom, an alkyl group, an aryl group, an aralkyl group, a carboxylic acid group, and the like can be mentioned.

Preferably, trihydroxybenzophenone or tetrahydroxybenzophenone, more preferably,
2. ．． 3. 'I-trihydroxybenzophenone, 2
,3. 'l,lI-tetrahydroxybenzophenone.

The esterification rate for hydroxyl groups is preferably 3θ to 100%.

As the orthoquinonediazide compound used in the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination.

Among these orthoquinonediazide compounds listed above, 2. J, 'I-trihydroxybenzophenone has-naphthoquinonediazide (2) = s-sulfonic acid ester or haco-naphthoquinonediazide (2)-4(
- Naphthoquinonediazide (sulfonic acid ester, metacresol, formaldehyde, novolak resin)
2) -5-sulfonic acid ester or /1,2-naphthoquinonediazide (2) -q-sulfonic acid ester or a mixture thereof is more preferred.

The proportion of the orthoquinonediazide compound in the photosensitive layer is usually selected from the range of 3 to 1.0% by weight, preferably from θ to SO.

Conventionally known diazo compounds can be used as appropriate for negative-working photosensitive lithographic printing plates that do not require dampening water, and are typified by condensates of aromatic diazonium salts and, for example, active carbonyl-containing compounds, especially formaldehyde. Diazo resins are included, among which diazo resins soluble in organic solvents are preferred.

Preferred specific examples of the diazo resin include resins represented by the following general formula (4) and having a molecular weight of approximately SOO to lo, ooo.

In the formula, R3, R4 and R5 each represent a hydrogen atom, an alkyl group or an alkoxy group, preferably a hydrogen atom,
R6 represents a hydrogen atom, an alkyl group or a phenyl group, preferably a hydrogen atom.

X in the formula represents a counter anion of the diazo resin, specifically PF6. It shows organic carboxylic acids such as BF4, decanoic acid, and benzoic acid, organic phosphoric acids such as phenylphosphoric acid, and sulfonic acids such as methanesulfonic acid.

Y in the formula represents NH, S or 0.

Furthermore, Z in the formula represents a sulfonic acid group, a sulfonate (Na
salt, K salt, etc.) group, sulfine group, sulfinate (Na
represents a phenyl group or a naphthyl group substituted with at least seven or more substituents selected from the group consisting of OH group and COOH group. The molar ratio of m and n is m/H=17 (1 to 10, preferably 110 to 2).

The content of diazo resin in the photosensitive layer is preferably 7 to 70
% by weight, more preferably from 3 to AO weight %.

The binder resin used in the photosensitive layer of the present invention is a graft polymer having a repeating unit represented by the following general formula (5) in the side chain (branch polymer).

→Si −0u− ・・・・・・(5) Here R7, R
8 is a hydrogen atom, unsubstituted or substituted (for example)
・Number of carbon atoms (by rogen atom, cyano group, amino group)/
It is arbitrarily selected from a methyl group, an alkyl group, an alkenyl group, or a phenyl group of ~/θ. The molecular weight of the branched polymer is arbitrary, but preferably the number average molecular weight (G
PC method, polystyrene equivalent) is 700~/0.000
degree, particularly preferably 3-00 to q,oo.

It is within the range of .

Such graft polymers can be used, for example, in [Kobunshi Ronshu J.
Vol, /13, A/ /, P, 711
/ (/qgA), a macromonomer having a polymerizable functional group at the end of a polyorganosiloxane,
It can be synthesized by copolymerizing this with a copolymerizable monomer (macromonomer method).

When used in radical polymerization, the terminal polymerizable functional group of the macromonomer of polyorganosiloxane includes, for example, a methacryloyl group, an acryloyl group, a crotonoyl group, an isocrotonoyl group, an oleoyl group, and the like. Preferred are methacryloyl group, acryloyl group, and crotonoyl group. In addition, when polymerizing with polyester or polyamide, examples of terminal polymerizable functional groups include hydroxyl group, dihydroxyl group, carboxyl group, and dicarboxyl group.

In the present invention, as a binder resin or other binder resins (e.g. acrylic resin, novolac resin,
The copolymerization component of the main chain (stem polymer) of the graft polymer having polyorganosiloxane units in the side chain (branch polymer) used by mixing with polyester, polyamide, etc.) is a copolymerizable component that can be copolymerized with the above macromonomer. It is a monomer.

In particular, as monomers for radical polymerization constituting these main chains, the following compounds having unsaturated bonds are used.

(1) Monomers having a hydroxyl group: λ-hydroxyethyl (meth)acrylate, (in this specification, (meth)acrylic)
Expressions such as ``acrylic'' and methacrylic compounds were used as a general term for acrylic and methacrylic compounds. ) λ-hydroxyglobil (meth)acrylate, co-hydroxypentyl (meth)acrylate, co-hydroxyphenyl (meth)acrylate, co-hydroxyphenyl (meth)acrylate and other (meth)acrylate monomers, N-methylol (
meth)acrylamide, N-hydroxyethyl(meth)
Acrylamide, (meth)acrylamide monomers such as N-(hydroxyphenyl)-(meth)acrylamide, N-(hydroxynaphthyl)-(meth)acrylamide, 0-1m--1p-hydroxystyrene monomers, etc. (2) ( ], ) (Meth)acrylic acid ester or amide monomers other than ): Methyl (meth)acrylate, ethyl (meth)azilylate, propyl (meth)acrylate, butyl (meth)
Alkyl (meth)acrylates such as acrylate, N
-Phenyl (meth)acrylamide, 0-1m-1p-
Methoxyphenyl (meth)acrylamide, 0-1m-
1p-Ethoxyphenyl (meth)acrylamide, etc. (3) Monomers having a cyano group in the side chain = (meth)acrylonitrile, 2-pentenitrile, λ-methyl-3
-butenenitrile, cocyanoethyl acrylate, o
-1m-1p-cyanostyrene, etc. (4) Monomers having carboxylic acid in the side chain: (meth)
Acrylic acid, itaconic acid and its anhydride, maleic acid and its anhydride, crotonic acid, etc. (5) Vinyl ethers: Probyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc. (6) Styrenes: α-methylstyrene, Methylstyrene, chloromethylstyrene, styrene, etc. (7) Vinyl ketones: Methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, etc. (8) Monomers other than (1) to (7): ethylene, propylene, imbutylene, phtadiene , olefins such as vinyl chloride, N-vinylpyrrolidone, N-vinylcarbazole, govinylpyridine, etc.
Other monomers that can undergo radical copolymerization with these monomers may be used. In the present invention, the above (1)
, (2), (3) and/or (4) are preferred.

Although specific monomers have been listed as constitutional units of the main chain (stem polymer) component, the present invention is not limited to only those listed above.

Furthermore, it is also possible to use a macromonomer having polyalkyl (meth)acrylate in the side chain for the purpose of improving ink receptivity. Examples of such macromonomers include terminal polymerizable functional groups such as methacryloyl group, acryloyl group, crotonoyl group, incrotonoyl group, and oleoyl group, and side chains (branched polymers).
Examples include polyalkyl (meth)acrylates such as polyethyl (meth)acrylate, polyprobyl (meth)acrylate, and polybutyl (meth)acrylate.

The number average molecular weight of these macromonomers is preferably in the range of soo-gooo.

In the above graft polymer, preferable examples of the structural unit having a polyorganosiloxane unit in the side chain include:
Examples include those represented by the following general formula (6).

-(-CH2-C-)-...(6)-O In the formula, R9, R11, R12 and R113 each represent a hydrogen atom, an alkyl group (methyl group, ethyl group, etc.) or a halogen atom, R10 is a linking group, for example, a cycloalkylene group (cyclohexylene group, etc.), an arylene group (
phenylene group, tolylene group, naphthylene group, etc.), alkylene group (carbon number/-5 alkylene group, etc.), and n represents an integer of 2 or more.

Further, preferable structural units constituting the copolymer with the above structural units include those represented by the following general formula (7) and/or (8).

In the formula, R14 and R'' each represent a hydrogen atom or an alkyl group (particularly preferably a methyl group or an ethyl group),
R15 represents a hydroxy group, an alkoxy group (methoxy group and ethoxy group are particularly preferred), or an alkoxy group. ) is shown.

The proportion of each of these structural units in the copolymer is expressed by the formula (6
) is 0. /~SO weight ratio, preferably 0.3-20% by weight, the structural unit represented by formula (7) is 0-99.9% by weight, preferably /θ~990-9
It is preferable that the structural unit represented by 9% by weight is in the weight ratio of θ to go, preferably /θ to 600 to 60% by weight.

As for the molecular weight of the graft polymer, those having a weight average molecular weight of 70,000 to 1,000,000, preferably S to 100,000, as determined by the generally known gel permeation chromatography method, are used. As a binder resin that can be used in combination with a graft polymer having siloxane as a branch polymer, in the case of a positive binder resin, for example, JP-A No. 6, No. ,?
These include novolac resins as described in Japanese Patent Application Laid-Open No. 36630, acrylic resins as described in Japanese Patent Application Laid-Open No. 793.211. In the case of a negative type, for example, JP-A-6λ~! Acrylic resin as described in the r99'lt publication, Tokukosho! 17-20AI'1
Polyester resins such as those described in the above publication, as well as polyamides, etc. can be used.

Containment of these polymer compounds when a graft polymer having polyorganosiloxane as a branch polymer is used alone as a binder or in combination with other binder resins (for example, acrylic resin, novolac resin, polyester, polyamide, etc.) The amount is preferably from 3θ to 99% by weight, particularly preferably from 0 to 97% by weight, in the photosensitive layer in both positive and negative photosensitive layers.

Also, graft polymers with polyorganosiloxane as branch polymers and other binder resins (e.g. acrylic resins, novolac resins, polyesters, polyamides, etc.)
The ratio of the graft polymer to other binder resins is 99% by weight or less, particularly preferably from o, i to 70% by weight.

The thickness of the photosensitive layer is preferably 0.7 μm to 10 μm,
It is in the range of 7μm-gμm.

In addition to the above-mentioned materials, the photosensitive layer of the photosensitive lithographic printing plate that does not require dampening water of the present invention may contain dyes, pigments, coatability improvers, plasticizers, Agents, oil sensitizers, stabilizers, etc. can be added.

It is advantageous that the photosensitive layer of the positive type photosensitive lithographic printing plate that does not require dampening water further contains a known exposure-visible image imparting agent.

Examples of the above dyes include Victoria Pea Blue BOH, Oil Blue+-Otsu θ3, and Oil Pink≠31.
Yu, patent pure blue, crystal violet,
Leuco Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Clean, Erythrosin B, Peisinoku Fuchsin, Malachite Green, Leucomalachite Green, m-Cresol Purple, Furesolet, Gyslenol Blue, Rhodamine B1 Auramine, II-p-diethylamino Examples include triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes represented by phenyliminonaphthoquinone, cyano-p-diethylaminophenyl acetanilide, and the like.

The dye is usually contained in the photosensitive layer in an amount of about O1θ/ to about /θ weight percent, preferably about o, o s -g weight percent.

Examples of the coating property improver include alkyl ethers (e.g., ethylcellulose, methylcellulose), fluorine-based surfactants, and nonionic surfactants (e.g., Pluronic L-BP (manufactured by Asahi Denka)). .

Examples of plasticizers that impart flexibility and abrasion resistance to the coating film include butylphthalyl, polyethylene glycol,
Examples include tributyl citrate, diethyl phthalate, dihexyl phthalate, dibutinopephthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrafulfurino oleate, acrylic acid, and oligomers of methacrylic acid.

As the oil-sensitizing agent for improving the oil-sensitivity of the image area, for example, styrene described in Japanese Patent Application Laid-Open No. 2003-100000 S-S, No. 2'Y is used.
Examples include half-esterification products of maleic anhydride copolymers with alcohol.

Furthermore, various liposensitizing agents having hydrophobic groups, such as p-octylphenol-formalin novolac resin, p-'t
-Butylphenol-formalin novolac resin, p-
Modified novolak resins such as 't-butylphenol benzaldehyde resin, rosin modified novolak resin, and these modified novolak resins. - Naphthoquinone diazide sulfonic acid ester (esterification rate of OH group - 0 to 70 moles), etc. can be added.

Examples of stabilizers include polyacrylic acid, tartaric acid, phosphoric acid, phosphorous acid, organic acids (acrylic acid, methacrylic acid,
citric acid, oxalic acid, benzenesulfonic acid, naphthalenesulfonic acid, +-methoxycohydroxybenzophenone-5-sulfonic acid, etc.).

The amount of these additives added varies depending on the purpose of use, but in general, the amount of θ, θ/weight ~ 3θ based on the total solid content
Weight percent is preferred.

The photosensitive layer of the positive type photosensitive lithographic printing plate that does not require dampening water may further contain a known exposure-visible image imparting agent.
The exposure visible image imparting agent is a compound that generates an acid upon exposure to form a salt with a dye.

As a compound that generates an acid upon exposure to light, a trihaloalkyl compound represented by the following general formula is preferred.

x in l L.

(However, Xa is a trihaloalkyl group having carbon atoms/~3, W is N or P, and Z is 0, S or S.
e, and Y is a group that cyclizes W and Z and has a chromophore. ) Specific compounds include oxadiazole compounds having a benzofuran ring such as =26=,
Cotrichloromethyl-3-(p-methoxystyryl) described in JP-A No. 3'I-7"I'72g
-/,',3. Examples include y-oxadiazole compounds.

In addition, q-(,2,y-dimethoxy-coustyryl)-A- described in JP-A No. 33-36223
ToIJ Chloromethyl-Coheron compound, Co, Gubis-(trichloromethyl)-A” p-methoxystyryl-8-triazine compound, λ, lI-bis-(trichloromethyl)□-6-p-dimethylaminostyryl-5 −
) riazine compounds and the like.

The amount of the exposure visible image imparting agent added is 0.0/~20 in the photosensitive layer.
It is preferably % by weight, more preferably 0.1~//
θ is % by weight.

The photosensitive layer of the present invention is formed by dissolving each of the above-described components in a solvent, coating the solution on a silicone rubber layer, and drying the solution.

The method for producing a photosensitive lithographic printing plate that does not require dampening water according to the present invention will be explained below.

First, a silicone rubber layer is applied onto the substrate.

The coating solvent and others are as described above, and the coating method can be conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating. After application, cure the silicone rubber sufficiently. In some cases, in order to improve the adhesion between the silicone rubber layer and the substrate, a silane coupling agent or silicone primer may be applied to the substrate, or a silane coupling agent or silicone primer may be added to the silicone rubber layer. You may.

Next, a photosensitive layer is applied onto the silicone rubber layer.

The photosensitive layer is coated by dissolving each of the above-mentioned components in a solvent. Examples of solvents that can be used include methylcellosolve, methylcellosolve acetate, ethylcellosolve, ethylcellosolve acetate and other cellulubs, methylcalpitol, Carpitols such as ethylcarpitol, dimethylformamide, dimethyl sulfoxide, dioxane,
Examples include acetone, methyl ethyl ketone, cyclohexanone, trichloroethylene and the like. These solvents may be used alone or in combination. The silicone rubber layer can be coated by conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating. After coating, the coating film is sufficiently dried to obtain a photosensitive lithographic printing plate that does not require dampening water.

Conventional methods can be applied to plate-making the photosensitive lithographic printing plate that does not require dampening water of the present invention obtained as described above. That is, a relief image is obtained by exposing the transparent original image having a line image, halftone image, etc. to light 7 and then developing it with an aqueous developer. A suitable light source for exposure is /gO
Any general-purpose light source including ultraviolet rays and visible light of nm or more may be used, but carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, etc. are particularly preferred.

The developer used in the development of the photosensitive planographic printing plate that does not require dampening water of the present invention may be any known developer. When a graft polymer having a chain (branch polymer) is mixed with a novolak resin, development can be performed using an alkaline aqueous solution (described later) that does not contain an organic solvent. In other cases, it is preferable to use a mixture of a specific organic solvent with an alkaline aqueous solution. The specific organic solvent herein refers to an organic solvent that can dissolve or swell the non-image areas of the photosensitive layer mentioned above when contained in the developer, and that has a solubility in water of 70% by weight or less at room temperature. say. Such organic solvents only need to have the above-mentioned characteristics. Specifically, for example, carboxylic acid esters such as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate, butyl levulinate, ethyl butyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketones, ethylene glycol motubutyl ether, ethylene glycol monobenzyl ether, ethylene glycol monophenyl ethyl, benzyl alcohol, methylphenyl carbinol, n-amyl 7 alcohol, alcohols such as methyl amyl alcohol, xylene and halogenated hydrocarbons such as methylene cyclolide and monochlorobenzene. One or more of these organic solvents may be used. Ethylene glycol monophenyl ether and benzyl alcohol are particularly effective. However, the content of these organic solvents in the developer is approximately 7 to 20% by weight, particularly preferably 2 to 10% by weight.

Certain solubilizers may also be included to aid in the solubility of these organic solvents in water. Such solubilizers include those that are more water-soluble than the above-mentioned organic solvents,
It is better to use low molecular weight alcohols and ketones. Furthermore, anionic activators, amphoteric activators, etc. can also be used. Examples of such alcohols and ketones include t
Hamethanol, ethanol, propanol, acetone,
Methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methoxybutanol, ethoxybutanol, goomethoxy
Preferably, methylbutanol, N-methylpyrrolidone, etc. are used. Preferred examples of the activator include sodium isopropylnaphthalene sulfonate, sodium n-butylnaphthalene sulfonate, sodium N-methyl-N-pentadecylaminoacetate, and sodium lauryl sulfate. The content of these solubilizers is preferably 30% by weight or less.

On the other hand, alkaline agents contained in the developer include (g) sodium silicate, potassium silicate, potassium hydroxide, sodium hydroxide, lithium hydroxide, sodium or ammonium salts of dibasic or tertiary phosphoric acid; , silium metasilicate, ammonia, etc. Mono, di or trimethylamine, mono, di or triethylamine, mono or diisopropylamine, n-butylamine, mono, di or triethanolamine, mono, di or trimethylamine triisopropanolamine,
Examples include organic compounds such as ethyleneimine and ethylenediamine.

Preferred are (g) sodium silicate and potassium silicate, and (g) organic amine compounds. Particularly preferred is
Potassium silicate and di- or triethanolamine.

The content of these alkaline agents in the developer is usually 0.
．． The content is preferably O, S to 6% by weight in terms of 05-g weight.

Further, in order to improve storage stability and the like, it is preferable to include a water-soluble sulfite in the developer as necessary. Such water-soluble sulfites are preferably alkali or alkaline earth metal salts of sulfite, such as sodium sulfite, potassium sulfite, lithium sulfite, magnesium sulfite, and the like. The content of these sulfites in the developer is usually θ, θS-g weight ratio, preferably 0.
/ -/I am in charge of weight.

After imagewise exposure, the photosensitive lithographic printing plate of the present invention that does not require dampening water can be brought into contact with the above-mentioned developer or rubbed, after 70 to 10 seconds at about /θ°C to 0°C. In this case, the photosensitive layer in the non-image area is completely removed without adversely affecting the image area of the photosensitive layer. A lithographic printing plate is thus obtained.

(Examples) The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Synthesis Example/ (Synthesis Example of Polyorganosiloxane Macromonomer) α,ω-Dihydroxydimethylpolysiloxane Q't"og"(0,"1 mol) represented by the following formula and H3 pyridine q, t, t γ-methac=35-lyloxypropylmethyldichlorosilane/λ, OAg is added to a solution of q g (o, 72 mol) dissolved in diethyl ether g ooff17!
A 70% solution of (o, o s mol) in diethyl ether was gradually added dropwise at room temperature over 7 hours.

The reaction proceeded immediately and white crystals of pyridine hydrochloride were precipitated. After the addition was completed, the mixture was further stirred at room temperature for 7 hours, and the crystals of pyridine hydrochloride were removed by filtration. Next, this filtrate was put into a separatory funnel, and 500 - of water was added thereto, thoroughly shaken, and washed with water. After washing with water, the separatory funnel was left standing to separate the upper ether layer and the lower aqueous layer, and anhydrous sulfate was added to the obtained ether layer, which was then left overnight at room temperature to dehydrate.

Thereafter, the anhydrous sulfur was removed by filtration, and the resulting filtrate was distilled under reduced pressure to remove the ether, resulting in a polyorganosiloxane macromonomer having a methacryloyl group as a polymerizable functional group at the end and having a number average molecular weight. is approximately S, Oθ
O dimethylpolysiloxane macromonomer 22311
I got it.

Synthesis Example (Synthesis Example of Graft Polymer) Under a nitrogen stream, each component shown in the table and 5 mol of azobisinbutyronitrile (AIBN) were added to methyl ethyl ketone in an amount equal to S times its total weight. The mixed solution was heated at 40° C. for 6 hours while stirring. After the reaction was completed, methylcerenlube (for GY-'S-1, 1I-dioxane) was added and the solvent was replaced by distillation under reduced pressure. Furthermore, after refluxing for 7 hours at qo°C, the solid content was adjusted to 20%.

Table / In the table, AN is acrylonitrile, MA is methyl acrylate, EA is ethyl acrylate, MAA is methacrylic acid, PhMA is N-7enylmethacrylamide, M -
/ indicates a polybutyl acrylate macromonomer (AB-Otsu, manufactured by Toagosei Co., Ltd.), and M-2 indicates a dimethylborisiloxane macromonomer obtained in Synthesis Example /.

The amount of each component used is expressed as 1 - weight salary.

Reference example/(Photosensitive liquid) (a) Positive photosensitive liquid*1: Pyrogallol/acetone polycondensate/2-naphthoquinonediazide-5-sulfonic acid ester (esterification rate 30%, Mw=/, 500 ) (b) Negative photosensitive liquid = 38- *2: Hexafluorophosphate of a polycondensate of p-diazodiphenylamine and paraformaldehyde. This diazo resin has a weight average molecular weight of 2g00° as a polycondensation reaction product with β-naphthol.
As shown.

In the table, AN is acrylonitrile, MA is methyl acrylate, EA is ethyl acrylate, MAA is methacrylic acid, PhMA is N-phenylmethacrylamide, M-
/ is polybutyl acrylate macromonomer (AB-A
: Manufactured by Toagosei Co., Ltd.).

The amount of each component used is indicated by weight.

Examples/~15 (a) Evaluation of coating properties Toray silicone ■ was coated on an aluminum plate with a thickness θ of 3wn using a rotary coating machine at room temperature and /00 rpm.
A primer layer was provided on the sialuminium plate by applying a 5H-224O primer manufactured by Co., Ltd. and air-drying it at room temperature for 5 minutes.

On this primer layer, a silicone rubber liquid having the following composition was applied using a spin coater at room temperature and 0.000 rpm, air-dried for 3 minutes, and then dried at AO° C. for 2 minutes. Thereafter, the silicone rubber was left to cure sufficiently to form an ink repellent layer of //μ.

Composition of silicone rubber liquid (a) Dimethylpolysiloxane with hydroxyl groups at both ends 70
0 parts (viscosity/300θStokes) (b) 710 parts of methyl tris (methyl ethyl ketone oxime) silica (C) diptyltin diacetate
0.2 parts (d) Methylcyclohexane 3
00 parts Next, the photosensitive liquid shown in Reference Example 1 was applied onto the ink repellent layer using a rotary coating machine at 0°C/! ; Or
After coating, the coating state of the photosensitive layer on the ink repellent layer was evaluated. The results are shown in Table S.

Table 5 Evaluation of Coating Properties Unable to coat means that no photosensitive layer could be coated on the silicone rubber layer. Also, "coatable" means that the photosensitive layer was coated evenly and uniformly over the entire surface of the silicone rubber layer.

(b) Evaluation of printability The photosensitive lithographic printing plates that did not require dampening water and could be coated in the evaluation of printability were evaluated using a 3kW ultra-high pressure mercury lamp for 10 minutes.
The ink receptivity of the image area and the ink repulsion of the non-image area were evaluated by exposing to light from a distance of 0.6 nm, developing, and performing actual printing.

The developer used was Example S (mixed system with novolac resin)
The developer solution except 1 was developer solution 7 below. In the case of a positive type, 2 parts of the developing solution 7 diluted 72 times with water were immersed for 20 seconds at DEG C., and then washed with water. In the case of a negative type, 2 parts of the developer solution shown below was diluted 1 times with water and immersed for 10 seconds at DEG C., followed by washing with water.

Example S is 5DR-/, (manufactured by Konica ■) developer solution mixed with water.
Development was carried out by immersing the sample in a diluted product at 2° C. for qo seconds and then washing with water.

(Composition of developer solution) Benzyl alcohol SθV triethanolamine 75g Sodium sulfite
sg sodium butylnaphthalene sulfonate 25g water
Soog printing is Sun Offset 220
E (manufactured by San Printing Machinery ■) without supplying dampening water. The ink is Toyo King Ultra TKU Aquares G.
Sumi ink (manufactured by Toyo Ink Manufacturing Co., Ltd.) was used. Table 6 shows the results of evaluating the ink receptivity in the image area and the ink repulsion in the non-image area on the printed matter. The quality of the ink repulsion in the non-image area was judged based on whether the printed matter had scumming or not.

In addition, the ink receptivity of the image area was indicated by the number of sheets of waste paper.

Table B (Effects of the present invention) As explained in detail above, if the graft polymer having the polyorganosiloxane of the present invention as a branch polymer is used in the photosensitive layer, it will be possible to create a moisturizer that is extremely easy to manufacture and has good coating properties. A remarkable effect is obtained in that a water-free photosensitive lithographic printing plate can be obtained.

Therefore, the present invention is extremely useful industrially.

Applicant: Mitsubishi Kasei Corporation 7 others Representative Patent Attorney Naga Kagawa - Others/names

Claims (1)

[Claims] (1) A photosensitive lithographic printing plate that does not require dampening water, in which a silicone layer and a photosensitive layer are provided in this order on a substrate, and the photosensitive layer contains a polymer having polyorganosiloxane units in side chains. A photosensitive lithographic printing plate that does not require dampening water.