JPH0497359A - Waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To contrive the improvement of the scratch strength of a silicone rubber layer, the stain prevention due to the projecting and recessed parts of the pigment, a dying property and an image forming capability by constituting this plate with a 2-layer primer. CONSTITUTION:The primer layers are constituted of 2 layers; the primer layer is consisting of the upper and under layers and the primer layer constituting the upper layer is consisting of one material having an improved adhesiveness with the photosensitive layer and an improved ink printability and being rich in elasticity. Also the primer layer constituting the under layer has the improved adhesiveness with a supporting base and includes the pigment. As the thickness of each layer, the supporting base is 50-400mum, preferably 100-300mum, the photosensitive layer 0.05-10mum, preferably 0.5-5mum, and the silicon rubber layer 0.1-10mum, preferably 0.5-2.0mum. Thus the improvement of the scratch strength of the silicone rubber layer, the stain prevention due to the projecting and recessed parts of the pigment, the dying property, and the improvement of the image forming capability are contrived.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and more specifically, the primer layer has excellent dyeing properties and the silicone rubber layer has high scratch strength. The present invention relates to a photosensitive lithographic printing plate which is improved and does not require dampening water and is free from stains due to unevenness.

[Background of the Invention] Conventionally, as a photosensitive lithographic printing plate that does not require dampening water (referred to as a "plate material" when necessary), one in which a photosensitive layer and an ink repellent layer are sequentially coated on a support is known. . By exposing and developing this plate material, a lithographic printing plate that does not require dampening water (hereinafter referred to as "printing plate" as necessary) can be obtained.

This lithographic printing plate that does not require dampening water has an image area (ink receiving area).
and a non-image area (ink repellent area). For example, in a printing plate obtained from a positive-working warm water-free photosensitive lithographic printing plate, the silicone rubber layer in the unexposed area is removed, or the photosensitive layer and the silicone rubber layer are removed, and the photosensitive layer or primer layer is removed. The surface is exposed and becomes an ink-receptive image area.

On the other hand, in the exposed areas, the silicone rubber layer remains without being removed and becomes an ink-repellent non-image area. In this way, a lithographic printing plate that does not require dampening water is formed. Specifically, when ink is applied to the plate surface, the ink is repelled in non-image areas without using dampening water, so ink selectively adheres only to the image areas.

When the ink in the image area is transferred to a transfer object, a printed matter having an image corresponding to the image area is obtained.

The above-mentioned waterless photosensitive lithographic printing plates are usually provided with a primer layer to ensure sufficient adhesion between the photosensitive layer and the support. Lithographic printing plates have a narrow exposure latitude, and therefore have the disadvantage that when the exposure amount is too large, halation occurs and halftone dot reproducibility in highlight areas deteriorates. Japanese Unexamined Patent Publication No. 1-237551 is an improvement on this point.

This publication discloses that in order to prevent halation in the primer layer, a substance that prevents halation, such as a dye or a pigment, is added to the primer layer.

However, when dyes, pigments, etc., especially pigments are added to the primer layer, a problem arises in that the scratch strength of the silicone rubber layer decreases.

In addition, there was a problem that not only stains appeared due to unevenness or unevenness, but also sufficient and uniform dyeing could not be achieved.

Therefore, as a result of various studies on these problems, the inventors of the present invention found that by creating a two-layer structure, not only can the scratch strength of the surface be improved, but there is no staining due to unevenness, and the stainability is also improved. It has been found that a primer layer with excellent properties can be obtained. The present invention has been made based on this knowledge.

[Objective of the Invention] Therefore, the object of the present invention is to provide a dampening solution which has an improved scratch strength of the silicone rubber layer, is free from staining due to unevenness, and furthermore has improved dyeing properties, thereby improving the image forming ability as a whole. An object of the present invention is to provide an unnecessary photosensitive lithographic printing plate.

[Structure of the Invention] The object of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water and has a primer layer, a photosensitive layer, and a silicone rubber layer sequentially on a support, in which the primer layer is composed of two layers. This was achieved with a photosensitive lithographic printing plate that does not require dampening water.

The present invention will be explained in more detail below.

The present invention improves the scratch strength of the silicone rubber layer by configuring the primer layer of a photosensitive lithographic printing plate that does not require dampening water into two layers. can get.

The primer layer used in the present invention consists of two layers, namely an upper layer and a lower layer. The primer layer constituting this upper layer is one that has good adhesion to the photosensitive layer, has good ink receptivity and dyeability, and is rich in elasticity.

Specific examples of resins used for the upper layer of this primer layer include acrylic resin, epoxy resin, cellulose resin,
Modify vinyl resin, polyester resin, urethane resin, butadiene resin, isoprene rubber, polysulfide rubber, or epoxy resin with one or more of phenol, resorcinol, polyamide, furan resin, polysulfide, melamine, synthetic rubber, polyester, etc. resin,
Resins obtained by esterifying epoxy resins with fatty acids, phenolic resins, vinyl acetals, polyamides,
Examples include resins modified with one or more of nitrile rubber and neorene, and natural polymer compounds such as gelatin, albumin, casein, and soybean protein.

These resins may be used alone or in combination. However, the glass transition temperature of the resins used alone or in combination is preferably 50°C or lower.

Further, in order to impart dyeability, it is preferable to include a resin having a polar group such as a hydroxyl group, an ester group, an amide group, an ethylene oxide group, or an ether group.

The primer layer constituting the lower layer has good adhesion to the support and contains a pigment. Examples of resins used in this primer layer include epoxy resin, cellulose resin, vinyl resin, alkyd resin, coumaron-indene resin, phenol resin, polyester resin, urethane resin, acrylic resin, butadiene-acrylonitrile rubber, neorene rubber, polysulfide Rubber, resins obtained by modifying epoxy resins with one or more of phenol, resorcinol, polyamide, furan resin, polysulfide, melamine, urea, synthetic rubber, polyester, etc., and resins obtained by esterifying epoxy resins with fatty acids. Examples include resins obtained by modifying phenolic resins with one or more of vinyl acetals, polyamides, nitrile rubber, neorene, and the like.

These resins can be used by mixing or polymerizing with each other or with resins other than those mentioned above, as long as their compatibility allows.

The resin used in the present invention can be used in combination with various curing agents. The curing agent may be one that is cured by various energy rays such as light or heat, or it may be one that is cured naturally at room temperature by simply mixing or drying.

Furthermore, various additives such as reaction accelerators, catalysts, plasticizers, thermal deterioration inhibitors, etc. can be used for the purpose of improving productivity and manufacturing stability, improving various physical properties, etc.

The coating conditions and curing conditions for the primer layer composition used in the present invention are preferably determined as appropriate depending on the characteristics of each resin composition.

The method for coating the upper layer and the lower layer may be such that the lower layer is coated first and then the upper layer is coated, or the upper layer and the lower layer may be coated simultaneously.

The pigment added to the primer layer used in the present invention must have effective absorption at 400 nm, and must have a reflection absorbance of 0.3 or more when the primer layer is formed on the support or support. Yes, for example, azo pigments such as insoluble azo pigments, azo lake pigments, condensed azo pigments, and metal complex azo pigments, phthalocyanine pigments such as copper phthalocyanine, halogenated copper phthalocyanine, metal-free phthalocyanine, copper phthalocyanine lake, acid dye lake, and basic dye. For dyeing with lake, etc., use lake, anthracene pigment,
Condensed polycyclic pigments such as thioindigo pigments, perinone pigments, perylene pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, isoindoline pigments, fluorobine pigments, and pyrrocholine pigments, as well as nitroso pigments, alizarin lakes, and metal complex azomethine pigments. , aniline black, alkali blue, etc.

In addition, snow-like iron oxide, lead white, red lead, yellow lead, silver vermilion, ultramarine blue, deep blue, strontium chromate, titanium dioxide-coated mica (pearl luster pigment), titanium yellow, titanium black, zinc chromate , iron black, molybdenum red, molybdenum white, litharge, lithopone, cobalt blue, and other inorganic pigments, titanium oxide, zinc oxide, aluminum oxide and other metal oxides, barium sulfate, calcium carbonate, magnesium carbonate, colloidal silica, silica gel, anhydrous Examples include fine powders of inorganic substances such as silica.

When a heat treatment is performed when producing a support or a primer layer on a support, a pigment that is stable under the heat treatment conditions is selected.

The amount of the above-mentioned yellowed titanium oxide, pigment, dye, etc. to be added is not particularly limited, and may be within a range that satisfies the predetermined reflection absorbance conditions when actually forming the support or the primer layer on the support. Just choose.

The method for applying the primer layer used in the present invention is as follows:
At least one of the photosensitive liquid coating methods described below may be used.

As the photosensitive composition used in the present invention, either a positive-working photosensitive composition or a negative-working photosensitive composition can be used, but this positive-working photosensitive composition contains an orthoquinone diazide group. A polymer compound is mainly used, and the polymer compound containing an orthoquinone cyacyto group here refers to a reaction product of a compound containing an orthoquinone cyacyto group and an alkali-soluble resin, or a polymer compound containing an orthoquinone cyacyto group. It is used to mean either or both of the cases where it is a mixture of the compound containing the compound and the alkali-soluble resin.

Typical examples will be explained below.

As a polymer compound containing an orthoquinonediazide group,
Examples include ester compounds of 0-naphthoquinone diazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include phenol, 0
-cresol, m-cresol, p-cresol, 3.
Examples include m-phenols such as 5-xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin.

Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde,
Examples include furfural.

Preferred among these aldehydes are formaldehyde and benzaldehyde.

Furthermore, examples of the above-mentioned ketones include acetone, methyl ethyl ketone, and the like.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, o-mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/acetone resin, etc. .

The condensation rate of O-naphthoquinone cyacytosulfonic acid with respect to the OH group of the phenol in the O-naphthoquinone diazide compound (reaction rate with respect to one O11 group) is 15 to 80.
%, more preferably 20 to 45%.

Furthermore, as the O-quinonediaside compound used in the present invention, compounds described in JP-A-58-43451 can also be used.

Among the above 0-quinonediazide compounds, 1,2-henzoquinone cyasitosulfonyl chloride or 1,2-naphthoquinone diacytosulfonyl chloride is reacted with pyrogallol acetone condensation resin or 2,3,4-trihydroxyhensiphenone. The most preferred is the O-quinonediazide ester compound obtained by

As the 0-quinonediazide compound used in the present invention, each of the above compounds may be used alone, or 2f! The above compounds may be used in combination.

The polymer compound containing 0-quinonediazide used in the present invention preferably has a molecular weight of 1,500 or more, more preferably 2,000 or more, in view of coating properties.

The above-mentioned 0-quinonediazide compound is preferably used in combination with an alkali-soluble resin. Examples of alkali-soluble resins include novolac resins, vinyl polymers having phenolic hydroxyl groups, and condensation resins of polyhydric phenols and aldehydes or ketones described in JP-A-55-57841. Examples of the novolac resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-57841, and phenol-cresol-formaldehyde copolycondensation resin as described in JP-A-55-127553. Examples include copolycondensation resins of p-substituted phenol and phenol or cresol and formaldehyde as described above.

In addition, the vinyl polymer having a phenolic hydroxyl group is a polymer having a unit having the phenolic hydroxyl group in its molecular structure, and has the following general formula [1] to -numerical formula [
Polymers containing at least one structural unit of V] are preferred.

-Formula [I] (CR+J-CR3) CONH2-+ A-)-B-OH General formula [0] % formula % General formula [m] (CR1R2-CR:+) -0H General formula [TV code H Formula [ V] ○ H [In the formula, R1 and R2 each represent a hydrogen atom, an alkyl group or a carboxyl group, preferably a hydrogen atom. R
3 represents a hydrogen atom, a halogen atom or an alkyl group,
Preferably, it represents a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R4 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom. A represents an alkylene group optionally having a substituent that connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, m represents an integer of O to 10, and B has a substituent. represents a phenylene group that may have a substituent or a naphthylene group that may have a substituent. ] The polymer used in the photosensitive composition of the present invention preferably has a copolymer-type structure, and can be used in combination with the structural units represented by formulas [I] to [V] above. Examples of monomer units that can be used include ethylenically unsaturated olefins such as ethylene, propylene, imbutylene, butadiene, and isoprene, such as styrene, α-methylstyrene, p-
Styrenes such as methylstyrene and p-chlorostyrene,
For example, acrylic acids such as acrylic acid and methacrylic acid,
For example, unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, maleic anhydride, etc., such as methyl acrylate,
Ethyl acrylate, 〇-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-acrylate
Esters of α-methylene aliphatic monocarboxylic acids such as chloroethyl, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, and ethyl ethacrylate; nitrites such as acrylonitrile and methacrylonitrile; e.g. acrylamide; Amides such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, etc., vinyl esters such as vinyl acetate, vinyl propionate, vinyl henzoate, vinyl butyrate, etc. , vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, inbutyl vinyl ether, β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanite, such as 1-methyl-1-methoxyethylene,
Ethylene conductors such as 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-ditroethylene, such as N-vinylpyrol, N-vinylcarbazole, N-
There are N-vinyl monomers such as vinyl indole, N-vinylvirolone, and N-vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, aliphatic monocarboxylic acid esters and nitriles exhibit excellent performance for the purpose of the present invention and are therefore preferred.

Considering the applicability of these alkali-soluble resins,
Those having a molecular weight of 1,500 or more are preferable, and those having a molecular weight of 2,000 or more are more preferable.

In addition to the above-mentioned materials, these photosensitive compositions may also contain colorants such as dyes and pigments, sensitizing agents, plasticizers, surfactants, organic acids, acid anhydrides, and acids that can be removed by exposure to light. Compounds that may be generated can be added.

There are various types of negative photosensitive materials used in the present invention, and representative ones will be described below.

(1) Photosensitive composition containing diazo resin The diazo resin represented by the condensate of p-diazodiphenylamine and formaldehyde may be water-soluble or water-insoluble, but is preferably
7 and No. 57-43890, etc., which are water-insoluble and soluble in ordinary organic solvents are used. Particularly preferred is a diazo resin represented by the following general formula [I].

Formula [Ico[] where R+ R2 and R3 represent a hydrogen atom, an alkyl group, or an alkoxy group, and R4 represents a hydrogen atom, an alkyl group, or a phenyl group.

X indicates PF or BF, Y bar N H3-
Or indicates -〇-. ] The diazo resin is preferably used in combination with a film-forming resin, particularly a lipophilic polymer compound having a hydroxyl group. In addition to those listed above, such lipophilic polymer compounds include monomers having an aliphatic hydroxyl group in the side chain, such as 2
Copolymers of -hydroxyethyl acrylate or 2-hydroxyethyl methacrylate and other copolymerizable monomers can be mentioned. In addition to these, polyvinyl butyral resins, polyurethane resins, polyamide resins, epoxy resins, novolak resins, natural resins, etc. may be added as necessary.

Various polymeric compounds can be used as the binder used in combination with the diazonium salt, but preferably, JP-A-54-9
Monomers having an aromatic hydroxyl group as described in Japanese Patent No. 8613, such as N-(4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, o-, m-, or p - copolymers of hydroxystyrene, o-lm-, or p-hydroxyphenyl methacrylate, etc., with other monomers, hydroxyethyl acrylate units as described in U.S. Pat. No. 4,123,276. or polymers containing hydroxyethyl methacrylate units as main repeating units, natural resins such as shellac and rosin, polyvinyl alcohol, polyamide resins described in U.S. Pat. No. 3,751,257, and U.S. Pat. No. 3.66.
These include linear polyurethane resins, phthalated polyvinyl alcohol resins, epoxy resins condensed from bisphenol A and epichlorohydrin, cellulose acetate, cellulose acetate phthalate, and other cellulose resins described in the specification of No. 0097.

Examples of the alkali-soluble resin include novolac resin, vinyl polymer having a phenolic hydroxyl group, and JP-A-55-5
Examples include condensation resins of polyhydric phenols and aldehydes or ketones described in Japanese Patent No. 7841. Examples of novolac resins include phenol/formaldehyde resin, cresol/formaldehyde resin, and JP-A-5
Phenol-cresol-formaldehyde copolycondensation resin as described in JP-A No. 5-57841, p as described in JP-A-55-127553
Examples include copolycondensation resins of -substituted phenol and phenol or cresol and formaldehyde.

In addition to the above-mentioned materials, these photosensitive compositions also contain pigments such as dyes and pigments, sensitizing agents, plasticizers, surfactants, organic acids, acid anhydrides, and acidic substances when exposed to light. Compounds that can generate , etc. can be added.

These binders are present in the solid content of the photosensitive composition in an amount of 40 to 99%.
It is contained in an amount of 50 to 95% by weight. The diazo resin is contained in an amount of 1 to 60% by weight, preferably 3 to 30% by weight.

Other dyes, pigments such as pigments, fat-sensitizing agents, plasticizers, surfactants, etc. can be added to these photosensitive compositions.

(2) In the main chain or side chain of the polymer -C) I-CI (-C-
Photosensitive composition containing a polymer compound having groups Examples of such polymer compounds include polyesters, polyamides, and polycarbonates containing -CH-CH-C as a photosensitive group in the main chain or side chain of the polymer. (e.g., U.S. Patent No. 3,
030,208, 3°707.373 and 3.453.237)
; those containing photosensitive polyesters derived from (2-properidene) malonic acid compounds such as cinnamylidene malonic acid and difunctional glycols (for example, U.S. Pat. No. 2,956,878 and No. 3,173.78
7); cinnamate esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose, and the like (e.g., U.S. Pat. No. 2,690,966); , No. 2,752.37
2, No. 2,732.301, etc.).

These photosensitive compositions may contain other sensitizers, stabilizers, plasticizers, R materials, dyes, and the like.

(3) Photopolymerizable composition comprising an addition polymerizable unsaturated compound This composition preferably comprises (a) a vinyl monomer having at least two terminal vinyl groups, (b) a photopolymerization initiator, and ( C) Consists of a polymer compound as a binder.

As the vinyl caramer of this component (a),
No. 5093, No. 35-14719, No. 44-2872
It is described in each publication No. 7.

Acrylic or methacrylic acid esters of polyols, such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, or methylene bis(meth)acrylamide , bis(meth)acrylamides such as ethylene bis(meth)acrylamide, or unsaturated caramers containing urethane groups, such as di(2'-methacryloxyethyl)-2,4-tolylene diurethane, di( Examples include reaction products of diol mono(meth)acrylate and diisocyanate such as 2-acryloxethyl)trimethylene diurethane.

As the photopolymerization initiator for component (b), the compound represented by the general formula [1] can be used, but other types can also be used. carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, as described in Chapter 5 of ``Sensitive Systems'';
These include halogen compounds and photoreducible dyes. More specifically, it is disclosed in British Patent No. 1,459,563.

Furthermore, various known polymers can be used as the binder for component (C). Details of specific binders can be found in U.S. Patent No. 4. o72.527.

These photopolymerizable compositions contain thermal polymerization inhibitors, plasticizers,
It can contain dyes, pigments, etc.

(4) Photosensitive composition containing an azide group As the photosensitive azide compound, an aromatic azide compound in which the azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group is preferably used.

For example, polyazidostyrene, polyvinyl-p as described in U.S. Pat. No. 3,096,311;
-Azidobenzoate, polyvinyl-p-azidobenzal, reaction product of azidoarylsulfonyl chloride and unsaturated hydrocarbon polymer described in Japanese Patent Publication No. 45-9613, and Japanese Patent Publication No. 43-21017, 44
No.-229, No. 44-22954, No. 45-2491
Polymers having sulfonyl azide or carbonyl azide as described in each publication of No. 5 can be mentioned.

A liposensitizing agent and a surfactant added to the photosensitive composition,
The amount of additives such as sensitizers, stabilizers, thermal polymerization inhibitors, plasticizers, and pigments such as dyes and pigments varies depending on the type, but in general, they are included in the photosensitive composition contained in the photosensitive coating solution. 0.01 to 20% by weight, preferably 0.05 to 20% by weight based on the product
10% by weight is suitable.

The silicone rubber used in the present invention is represented by the following general formula [I], has a molecular weight of several thousand to several hundred thousand, and has a hydroxyl group in the main chain or at the end of the main chain. Preferably, the main component is a linear organic polysiloxane.

General formula [Ico(St-OTh) where n is an integer of 2 or more, R is an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxyl group, a vinyl group, an aryl group, one silanol group (0) ), and
Preferably, 60% or more of R is a methyl group. The silanol group (OH group) may be located either in the main chain or at the end of the main chain, but is preferably located at the end.

The silane coupling agent (or silicone crosslinking agent) used in the present invention includes Rn5iX4-.

(In the formula, n is an integer of 1 to 3, R represents a monovalent group such as alkyl, aryl, alkenyl or a combination thereof, and these groups include halogen, amine, hydroxy, alkoxy, aryloxy, thiol. It may have a functional group such as.

X is -011, -〇R2, -〇AC1-o-N-c,
Represents a substituent such as -ci, -Br, etc. Here 82, R3
represents the same as R above, and R2 and R3 may be the same or different. Moreover, Ac represents an acetyl group. ) is a silane compound represented by

That is, the silicone rubber useful in the present invention is obtained by a condensation reaction between such a silicone base polymer and a silicone crosslinking agent such as those listed above.

Specific examples of the silane coupling agent used in the present invention include HN [(CH2] asi (OMe) 3] 2
, vinyltriethoxysilane, C1' (CH2)s
si (OMe) 5, CH35i (08C) 3, R5
(C)12) ssi (OMe) s, vinyltris(methylethylketoxime)silane, and the like.

The silicone rubber described above is also available as a commercial product, such as YE-3085 manufactured by Toshiba Silicone Co., Ltd. Other useful silicone rubbers can be produced by reacting the above-mentioned base polymer with a silicone oil having repeating units represented by the following general formula [II], or by reacting a silicone oil in which about 3% of R is a vinyl group. It can also be obtained by addition reaction of silicone with a base polymer or reaction of the silicone oils with each other.

(In the formula, R has the same meaning as R, which is a substituent of the polymer represented by general formula [11], m is an integer of 2 or more, and n is an integer of 0 or 1 or more.) Through such a crosslinking reaction, To obtain silicone rubber, a crosslinking reaction is carried out using a catalyst. This catalyst includes tin, zinc, cobalt, lead,
Organic carboxylates of metals such as calcium, manganese, etc.
For example, dibutyltin laurate, tin(II) octoate, cobalt naphthenate, or chloroauric acid may be used.

Fillers can also be mixed in to improve the strength of the silicone rubber and to obtain a silicone rubber that can withstand the frictional forces generated during printing operations. Silicone rubber mixed with filler in advance is commercially available as silicone rubber stock or silicone rubber dispersion, and when it is preferable to obtain a silicone rubber film by coating as in the present invention, RTV
Alternatively, dispersion of LTV silicone rubber is preferably used. An example of this is sy+ Off 23,5RX-257,5H manufactured by Toray Silicone.
There are silicone rubber dispersions for paper coating such as 237.

In the present invention, it is preferable to use a synthetically crosslinked silicone rubber.

The silicone rubber layer preferably contains a silane coupling agent having an amino group in order to further improve adhesiveness.

Examples of preferable silane coupling agents include the following.

(a) H2NCH2CH2NH((:H2) 3Si
(OCH3) 3(b) H2NCE2CH2NH(
CH2) 351 (OCH3) 2 (CH3) (C
) H2N (CH2) 351 (OEt) 3 The silicone rubber layer used in the present invention can further contain a small amount of a photosensitizer.

The silicone rubber layer used in the present invention is prepared by dissolving silicone rubber in a suitable solvent, applying it onto the photosensitive layer, and drying it.

The support of the present invention is preferably one that is flexible enough to be set in a normal lithographic printing machine and that can withstand the load applied during printing, such as metal plates such as aluminum, zinc, copper, and steel, and metal plates such as chromium, zinc, Examples include metal plates plated or vapor-deposited with copper, nickel, aluminum, iron, etc., paper, plastic films, glass plates, resin-coated paper, and paper with exposed metal foils such as aluminum.

Among these, aluminum plates are preferred.

In addition, examples of the anchoring agent constituting the primer layer used in the present invention include the silane coupling agent,
Silicone primers and the like can be used, and organic titanates and the like are also effective.

The thickness of each layer constituting the plate material of the present invention is as follows. That is, the support has a thickness of 50 to 400μ, preferably 100μ
~300 μm, photosensitive layer 0.05-10 μl, preferably 0.5-5 μl, silicone rubber layer 0.1-1
It is 0 μm, preferably 0.5 to 2 μm.

In the present invention, a protective layer may be provided on the upper surface of the silicone rubber layer, if necessary.

The treatment for the support itself to improve the adhesion is not particularly limited, and includes various surface roughening treatments.

In particular, in the case of an aluminum plate support, it is preferable that the support be subjected to surface treatments such as graining, anodizing, and, if necessary, sealing.

As a method for the above-mentioned graining treatment, a technique is adopted in which the surface of the aluminum plate or the like is degreased and then a brush polishing method, a ball polishing method, a chemical polishing method, an electrolytic etching method, or the like is applied.

The above anodic oxidation treatment is performed using, for example, phosphoric acid, chromic acid, boric acid,
This is carried out by passing an electric current through an aluminum plate or the like as an anode in an aqueous or non-aqueous solution of an inorganic salt such as sulfuric acid, or an organic acid such as oxalic acid or sulfamic acid, or a mixture of 2 ff1 or more of these acids.

Furthermore, the sealing treatment is carried out by immersion in a hot aqueous solution of a sodium silicate solution, hot water, and some inorganic or organic salts, or by a steam bath.

In the present invention, the amount of photosensitive coating liquid applied to the support is as follows:
Depending on the application, the solid content is numerically 0.5 to 3.
．． 5 g/m2 is suitable.

Application methods for the coating liquid used in the present invention include dip coating, roll coating, reverse roll coating, air doctor coating, blade coating, loft coating, knife coating, squeeze coating, gravure coating, cast coating, curtain coating, and extrusion. A method such as coating is used, and the coating film thickness is 0.1 to 5.
g/m2 is preferred. In addition, the drying temperature is 20-150℃,
Preferably it is in the range of 30 to 100°C.

[Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

Example-1 [Synthesis of diazo resin-1] p-diazodiphenylamine sulfate 14.5 g (50
mmol) was dissolved in 40.9 g of concentrated sulfuric acid under water cooling.

To this reaction solution, 1.35 g (45 mmol) of rose formaldehyde was gradually added so that the reaction temperature did not exceed 10°C.

The reaction mixture was added dropwise to 500+au of ethanol under water cooling, and the resulting precipitate was filtered.

After washing with ethanol, this precipitate was dissolved in 10011 IIL of pure water, and to this solution was added a cold concentrated aqueous solution in which 6.8 g of zinc chloride was dissolved.

The resulting precipitate was filtered, washed with ethanol, and dissolved in 15011 pure water.

To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved.

The resulting precipitate was collected by filtration, washed with water, and then dried to obtain diazo resin-1.

Next, Primer Layer Composition-1 having the following composition was applied onto a degreased smooth aluminum plate having a thickness of 0Jrstn, and dried in hot air at 100°C for 3 minutes to form a coating film with a thickness of 4μ. ℃ for 3 minutes, and further coated with primer layer composition-2, and heated at 100℃ in the same manner.
Dry in hot air for 3 minutes to form a 4μ thick coating of 8μ in total.
After forming a coating film of upper and lower layers, the entire surface was exposed to light at 500 mJ/cm" and cured to form a primer layer.

[Primer layer composition-1] (1) 100 parts by weight of epoxy/phenol/urea resin (KP Color 8482, manufactured by Kansai Paint Co., Ltd.) (2) Blocked isocyanate (Takenate B-830, Takeda Pharmaceutical Co., Ltd.) Co., Ltd.)
100Jiji part (3) Titanium oxide
10 parts by weight (4) Ethyl cellosolve 1100 parts by weight (5) Dimethylformamide
200 parts by weight [Primer layer composition-2] (1) Diazo resin - 1101 parts by weight (2) Copolymer resin of 2-hydroxyethyl methacrylate/methyl methacrylate in a molar ratio of 60/40
100 parts by weight (3) γ-methacryloxypropyltrimethoxysilane
2 parts by weight (4) Methyl cellosolve 1
A photosensitive layer composition having the following composition was then applied onto the cured primer layer and dried for 2 minutes in hot air at 80° C. to form a photosensitive layer having a thickness of 0.4 μm.

[Photosensitive layer composition] (1) Diazo resin - 150 parts by weight (2) 2-hydroxyethyl methacrylate/N-(4
-Hydroxyphenyl) methacrylamide molar ratio 30
/70 copolymer resin (3) Victoria Pure Blue BOH (manufactured by Hodogaya Chemical Co., Ltd.; dye) 1 part by weight (4) Methyl cellosolve 1500 parts by weight Next, on the above photosensitive layer, from the following composition was applied. The silicone rubber layer composition was applied to a dry weight of 1.8 g/m' and dried in hot air at 90° C. for 5 minutes to obtain a silicone rubber layer.

[Silicone rubber layer composition (1) 100 parts by weight of dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight: 52.000) (2) 10 parts by weight of triacetoxymethylsilane (3) 0.8 parts by weight of dibutyltin laurate Part (4)
1000 parts by weight of Isopar E (manufactured by Exxon Chemical Co., Ltd., solvent) Furthermore, a 5 μm thick single-sided matted polypropylene film was laminated on the silicone rubber layer to obtain a photosensitive lithographic printing plate that did not require dampening water.

After vacuum-adhering a positive film to the top surface of the above plate material, a metal halide lamp was used as a light source and a 230mJ
/cm' exposure was performed.

Next, after being immersed in the following developer solution at 27°C for 1 minute, development was performed by rubbing the surface of the plate material with a pad impregnated with the developer solution, and the unexposed portions of the silicone rubber layer and photosensitive layer were removed. A printing plate with well reproduced halftone dots was obtained.

The image area of the above printing plate could be vividly dyed by applying a dyeing solution of the following composition to a cloth, lightly rubbing the plate, and then washing with water.

[Developer solution (1) β-anilinoethanol 0.5 parts by weight (2)
Propylene glycol 1.0 parts by weight (3) p-
Tert-butylbenzoic acid 1.0 parts by weight (4) Potassium hydroxide 1.0 parts by weight (5) Polyoxyethylene lauryl ether 0.1 parts by weight (6) Potassium sulfite 2.0 parts by weight (7)
Potassium metasilicate 3.0 parts by weight (8) water
91 parts by weight [staining solution] (1) Tulfit (manufactured by Clarei Soprene Chemical Co., Ltd.);
Solvent) 20 parts by weight (2) Rheodol T
W-0120 (manufactured by Kao Corporation, surfactant) 0.5 parts by weight (3) Benzyl alcohol 5.0 parts by weight (
4) Victoria Pure Blue BOH (manufactured by Hodokugaya Chemical Co., Ltd.; dye) 1.0 parts by weight (5) Water 100 parts by weight As a result of printing using the obtained printing plate, there was no color in the non-printing area. Approximately 30,000 sheets could be printed with almost no ink adhesion defects.

Example-2 Example except that the primer layer composition of Example-1 was changed as follows, and the overall exposure amount was set to IJ/cm2 without performing heat treatment after coating the primer layer composition-1. A photosensitive lithographic printing plate requiring no dampening water was obtained in the same manner as in -1, and exposed, developed, dyed and printed in the same manner. The above results are summarized in Table 1.

[Primer layer composition-1] (1) p-phinidia diacrylic acid ester and 1.4-
Molar ratio with dihydroxyethyloxycyclohexane: 1
: Photosensitive unsaturated polyester obtained by polycondensation of 1
00 parts by weight (2) 1-methyl-2-benzoylmethylene-β-naphthothiazoline 6 parts by weight (3) N
-(β-aminoethyl)aminomethylphenethyltrimethoxysilane 5 parts by weight (4) FINEX-25 (zinc oxide) (manufactured by Sakai Chemical Industry Co., Ltd., white pigment) 80 parts by weight (5) Methyl cellosolve 600 parts by weight ( 6) Methyl cellosolve acetate 600 parts by weight (7) Toluene 600 parts by weight [Primer layer composition-2] (1) Diazo resin - 110 parts by weight (2) Molar ratio of 2-hydroxyethyl methacrylate/n-butyl acrylate/acrylonitrile 40/30
/30 copolymer resin 100 parts by weight (3) Methyl cellosolve 1000 parts by weight Example-3 The primer layer composition-1 of Example-1 was changed as follows, and after coating the primer layer composition-1. Example-- except that no heat treatment was performed and the overall exposure amount was set to IJ/cm'.
A photosensitive lithographic printing plate which did not require dampening water was obtained in the same manner as in 1, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

[Primer layer composition-1] (1) Molar ratio of 2-hydroxyethyl methacrylate/glycidyl methacrylate/ethyl acrylate 35/
35/30 copolymer resin 100
Part by weight (2) Pentaerythritol triacrylate 8
0 parts by weight (3) 3 parts by weight of 2,4-diethylthioxanthone (4) p-dimethylaminobenzoic acid ethyl ester
3 parts by weight (5) 2 parts by weight of γ-aminopropyltriethoxysilane (6) FINEX-25 (zinc oxide) (manufactured by Sakai Chemical Industry Co., Ltd.; white pigment) 80 parts by weight (7) 700 parts by weight of methyl cellosolve ( 8) Ethyl cellosolve 700 parts by weight Example-4 The primer layer composition of Example-1 was changed as follows, and the entire surface exposure amount was increased to IJ/1 without heat treatment after coating the primer layer composition-1. A photosensitive lithographic printing plate requiring no dampening water was obtained in the same manner as in Example 1, except that the printing plate was set to cm', and exposure, development, dyeing, and printing were carried out in the same manner. The above results are summarized in Table 1.

[Primer layer composition-1] Primer layer composition-1 described in Example-3 [Primer layer composition-2] (1) Copolymer resin of 2-hydroxyethyl methacrylate/methyl methacrylate in a molar ratio of 40/60
100 parts by weight (2) 70 parts by weight of pentaerythritol acrylate (3) NK-ester A-600 (Shin Nakamura Chemical Co., Ltd.)
Made of polyethylene glycol 600 diacrylate)
20 parts by weight (4) 3.5 parts by weight of 2.4-diethylthioxanthone (5) p-dimethylaminobenzoic acid ethyl ester
3.5 parts by weight (6) γ-mercaptopropyltrimethoxysilane
1 part by weight (7) Methyl cellosolve 700 parts by weight (8) Ethyl cellosolve 800 parts by weight Example-5 The same procedure as Example-1 was carried out except that the primer layer composition of Example-1 was changed as follows. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner. The above results are summarized in Table 1.

[Primer layer composition-1] Primer layer composition-1 described in Example-1 [Primer layer composition-21 Primer layer composition-2 described in Example-4 Example-6 Primer layer of Example-1 The composition was changed as follows, and the heat treatment after coating of primer layer composition-1 was carried out at 120°C.
A photosensitive lithographic printing plate requiring no dampening water was obtained in the same manner as in Example 1, except that the time was 10 minutes, and exposure, development, dyeing, and printing were performed in the same manner. The above results are summarized in Table 1.

[Primer layer composition-1] (1) Niraporan 125 (Japan Polyurethane Industries Co., Ltd.)
Polyol for paints) 100 parts by weight (2) Coronate EH (Incyanate for paints manufactured by Nippon Polyurethane Industries Co., Ltd.) 15 parts by weight (3) Octenoic acid 03 parts by weight (4)
Ethyl acetate 200 parts by weight (5) Butyl acetate 100 parts by weight (6) Toluene
150 parts by weight (7) Methyl cellosolve acetate 50 parts by weight [Primer layer composition-2] Primer layer composition-2 described in Example-4 Comparative example-1 Only primer layer composition-1 of Example-1 was dried A dampening water-free photosensitive lithographic printing plate was obtained in the same manner as in Example 1, except that the primer layer was formed by coating, drying, and curing so that the film thickness was 8μ, and was exposed, developed, and exposed in the same manner. Dyeing and printing were done.

The above results are summarized in Table 1.

Comparative Example-2 A primer layer composition-2 of Example-1 was applied in the same manner as in Example-1, except that the primer layer was formed by coating, drying, and curing to a film thickness of 8μ after drying. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

Comparative Example-3 A primer layer composition-1 of Example-2 was applied in the same manner as Example-1 except that the primer layer was formed by applying, drying, and curing to a film thickness of 8μ after drying. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

Comparative Example-4 Primer layer composition-2 of Example-2 was applied in the same manner as Example-1, except that the primer layer was formed by coating, drying, and curing to a film thickness of 8μ after drying. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

Comparative Example-5 A primer layer composition-1 of Example-3 was applied in the same manner as Example-1, except that the primer layer was formed by coating, drying, and curing to a film thickness of 8μ after drying. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

Comparative Example-6 A primer layer was prepared in the same manner as in Example-1, except that only Primer Layer Composition-2 of Example-4 was applied, dried, and cured to a film thickness of 8μ after drying to form a primer layer. A photosensitive lithographic printing plate requiring no dampening water was obtained, and exposed, developed, dyed and printed in the same manner.

The above results are summarized in Table 1.

As is clear from Table 1 below, Examples 1 to 4 of the present invention are as follows:
It has good dyeability, and also has excellent halftone dot reproducibility, scratch strength resistance, and stiffness resistance.

On the other hand, the comparative examples had poor halftone dot reproducibility and poor dyeability. Even if the dyeability and scratch resistance are good as in Comparative Examples 2.4 and 6, the printing durability is poor.

[Effects of the Invention] In the present invention, by configuring the primer layer into two layers, the scratch strength of the silicone rubber layer is improved, there is no staining due to the unevenness of the pigment, and furthermore, the dyeability is improved, so that the overall image quality is improved. It has an excellent effect of improving the forming ability.

Applicant Konica Mitsubishi Chemical Corporation
Agent Patent Attorney Co., Ltd. Miki Nakajima Seishi Neho Seisho (self-motivated) June 14, 1991

Claims (1)

[Claims] A waterless photosensitive lithographic printing plate having a primer layer, a photosensitive layer, and a silicone rubber layer sequentially on a support, characterized in that the primer layer is composed of two layers. .