JPH0497357A - Waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To improvement the resistance for the damage of a silicon rubber layer and the enhancement of the yielding resistance by incorporating a plasticizer in a primer layer on a supporting base. CONSTITUTION:The primer layer incorporates the plasticizer. As the plasticizer being added in the primer layer, phthalate esters, phosphate esters, adipate esters, sebacate esters, citrate esters, maleate esters, fumalate esters, trimelitate esters, polyester compounds, epoxy compounds, and chlorinated n-paraffines, polyvinyl bityl ether, polyvinyl ethyl ether, polyvinyl formal, dinonyl naphthalene, camphor, chorinated diphenyls, paraffins, etc., are exemplified. The adding quantity of those plasticizers is 1-50wt.% and is preferably 10-40wt.%. Thus the improvement of the resistance for the damage of the silicon rubber layer and the enhancement of the yielding resistance are contrived.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and more specifically, it improves the scratch resistance of the silicone rubber layer and increases the printing durability. This invention relates to a photosensitive lithographic printing plate that does not require dampening water and has improved properties.

[Background of the Invention] Conventionally, photosensitive lithographic printing plates (hereinafter referred to as "plate materials" as necessary) that do not require dampening water have been known to have a photosensitive layer and an ink repellent layer coated on a support in this order. It is being By exposing and developing this plate material, a lithographic printing plate that does not require dampening water (hereinafter referred to as "r printing plate" if necessary) can be obtained.

Generally, in plate materials, a primer layer is provided between the support and the photosensitive layer in order to improve the adhesion between them.

The silicone rubber layer of such plate materials is easily damaged by being transported in layers, or by the surface of the silicone rubber layer being rubbed by dirt, sand, etc. during printing. Become.

In order to prevent this damage, it is possible to increase the strength of the silicone rubber layer or strengthen the adhesion of the silicone rubber layer, but this may cause poor development or reduce the repellency of ink spots during printing. There are drawbacks such as the occurrence of background stains due to the drop in color.

Therefore, the present inventors focused on the primer layer and added a plasticizer to the primer layer to strengthen the adhesion between the support and the photosensitive layer, thereby reducing the scratch resistance of the silicone rubber layer. It has been discovered that the method can be improved, and the present invention has been hereby accomplished.

[Object of the Invention] Accordingly, an object of the present invention is to provide a photosensitive lithographic printing plate which improves the scratch resistance of the silicone rubber layer and thereby has improved stiffness resistance and does not require dampening water.

[Structure of the Invention] The above-mentioned 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 in this order on an aluminum support, in which a plasticizer is added to the primer layer. This was achieved with a photosensitive lithographic printing plate that does not require dampening water and is characterized by containing:

Below, the configuration of the present invention will be explained in more detail.

The present invention improves the scratch resistance of the perilla rubber layer by incorporating a plasticizer into the primer layer of a water-free photosensitive planographic printing plate, and provides a water-free photosensitive planographic printing plate with excellent rigidity. Obtainable.

Examples of the plasticizer added to the primer layer include phthalate esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dilauryl phthalate, dicyclohexyl phthalate, and hydroxyphthalic anhydride.

Examples of phosphoric acid esters include tricresyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate,
Examples include octyl diphenyl phosphate.

As adipate ester, dioctyl adipate,
Examples include diisononyl adipate and dibutyl diglycol adipate.

Examples of sebacic acid esters include dibutyl sebacate and dioctyl sebacate.

Examples of citric acid esters include acetyl triethyl citrate, acetyl tributyl citrate, and the like.

Examples of maleic esters include dibutyl maleate and diethylhexyl maleate.

Examples of fumaric acid esters include dibutyl fumarate and the like.

Examples of trimellitic acid esters include trialkyl trimellitate and the like.

Examples of the polyester compound include an ester of adipic acid and propylene glycol, an ester of sebacic acid and butyl glycol, and the like.

Epoxy compounds include epoxy triglyceride,
Examples include alkyl epoxy stearate.

Other examples include normal paraffin chloride, polyvinyl butyl ether, polyvinylethyl ether, bobbinyl formal, dinonylnaphthalene, camphor, diphenyl chloride, and paraffin.

The amount of this plasticizer added is 1% to 50% by weight,
Preferably it is 10% to 40% by weight.

In the present invention, either a positive-working photosensitive composition or a negative-working photosensitive composition can be used. A polymer compound containing an orthoquinonediazide group is a reaction product of a compound containing an orthoquinonediazide group and an alkali-soluble resin, or a compound containing an orthoquinonediazide group and an alkali-soluble resin. It is used to mean a mixture of either or both.

Typical examples of polymer compounds containing 6-orthoquinone diazito groups include, for example, O-
Examples include ester compounds of naphthoquinone cyasitosulfonic 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 rogallol 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, and the like.

The condensation rate (0) of the 0-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol of the 0-naphthoquinonediazide compound (reaction rate per 1 group) is 15 to 80.
%, more preferably 20 to 45%.

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

Among the above 0-quinonediazide compounds, it is obtained by reacting 1.2-penzoquinonediazide sulfonyl chloride or 1.2-naphthoquinonediazide sulfonyl chloride with a pyrogallol acetone condensation resin or 2,3.4-trihydroxybenzophenone. O-quinonediazide ester compounds are most preferred.

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 the alkali-soluble resin include novolak resin, a vinyl polymer having a phenolic hydroxyl group, and those described in JP-A-55-57841. Examples include condensation resins of polyhydric phenols and aldehydes or ketones. 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 general formula [
Polymers containing at least one structural unit of V] are preferred.

General formula [I] (CR+th-CRs + C0NR, +^+B-OH - Formula [II] General formula [II+] + (: R12-CR+ + [1-OH General formula [rV] H General formula [V co H [In the formula, R+ and R2 each represent a hydrogen atom, an alkyl group, or a carboxyl group, preferably a hydrogen atom.R
6 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 0 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 [1] to [V] above. Examples of monomer units that can be used include ethylenically unsaturated olefins such as ethylene, propylene, isobutylene, 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 benzoate, vinyl butyrate, etc. , vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as 1-methyl-1-methoxyethylene,
Ethylene conductors such as 1,1-dimethoxyethylene, 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, l-methyl-1-ditroethylene, such as N-vinylpyrol, N-vinylcarbazole, N-
There are N-vinyl polymers such as vinyl indole, N-vinylvirolone, and N-vinylpyrrolidone. These vinyl-based caramers 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 1,000 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 also contain pigments such as dyes and pigments, sensitizing agents, plasticizers, surfactants, organic acids, acid anhydrides, and acidic substances when exposed to light. A compound etc. that can generate 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 [1]''.

General Formula [I] [In the formula, RI 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 represents PFs or BF4, and Y represents -NH--S- or -0-. ] 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 the above-mentioned lipophilic polymer compounds, examples of such lipophilic polymer compounds include those having an aliphatic hydroxyl group in the side chain, for example, 2
Examples include copolymers of -hydroxyethyl acrylate or 2-hydroxyethyl methacrylate and other copolymerizable polymers. 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-, m-, 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 the main repeating unit, natural resins such as shellac and rosin, polyvinyl alcohol, polyamide resins described in U.S. Pat. No. 3,751.257, U.S. Pat. No. 3,66
0.097, a phthalated polyvinyl alcohol resin, an epoxy resin condensed from bisphenol A and epichlorohydrin, and celluloses such as cellulose acetate and cellulose acetate phthalate.

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/rinizole/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. A compound etc. that can generate can be added.

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

To these photosensitive compositions, other pigments such as dyes and pigments, fat-sensitizing agents, plasticizers, surfactants, etc. can be added.

(2) A photosensitive composition containing a polymer compound having -C)I-CH-C- group in the main chain or side chain of the polymer. Those whose main component is a photosensitive polymer such as polyesters, polyamides, and polycarbonates containing -CH-CH-C- as a photosensitive group (for example, U.S. Patent No. 3,
030,208, 3°707.373 and 3.453.237)
Those based on photosensitive polyesters derived from (2-probelidene) malonic acid compounds such as nisinnamylidene malonic acid and difunctional glycols (e.g., U.S. Pat. No. 2,956,878 and U.S. Pat. 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); , same No. 2,752,37
2, No. 2,732,301, etc.).

These photosensitive compositions may contain other sensitizers, stabilizers, plasticizers, pigments, 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.

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

Acrylic or methacrylic 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 monomers containing urethane groups, such as di(2'-methacryloxyethyl)-24-tolylene diurethane, di(2- Examples include reaction products of diol mono(meth)acrylates and diisocyanates, such as acryloxyethyl) trimethylene diurethane.

As the photopolymerization initiator of component (b), the compound represented by the general formula [I] can be used, but other types can also be used. For example, carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo and diazo compounds, halogen compounds, and photoreduction as described in Chapter 5 of ``Light Sensitive Systems'' by J. Kosar. There are sex pigments. 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, plasticizing agents, and pigments such as dyes and pigments varies depending on the type, but in general, the amount of additives contained in photosensitive coating liquids is 0.01 to 20% by weight, preferably 0.05 to 1% by weight based on the composition
0% by weight is suitable.

Dyes preferably used in the present invention include basic dyes and oil-soluble dyes. Specifically, Victoria Pure Blue BOH, Victoria Blue BH, Methyl Violet, Cramps Malachite Green (manufactured by Hodogaya Chemical Industry), Patent Pure Blue
Basic dyes such as vx, Rhodamine B, Methylene Blue (manufactured by Sumitomo Chemical Co., Ltd.), Sudan Blue II, Victoria Blue F4R (B.

A, S, F), oil blue-#603, oil
Oil-soluble dyes such as Blue BOS and Oil Blue IIN (manufactured by Orient Chemical Industry Co., Ltd.) are exemplified.

The silicone rubber layer used in the present invention is not particularly limited as long as it has ink repellency.

In particular, it is preferable to use a condensation crosslinked silicone rubber layer.

The silicone rubber used in the present invention is a linear organic polymer having a repeating unit represented by the following general formula [I] and having a molecular weight of several thousand to hundreds of thousands and a hydroxyl group in the main chain or at the end of the main chain. Those containing siloxane as a main component are preferred.

General formula [I] 1+5i-oi ■ Here, R 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, a silanol group (0) 1 basis), 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 R11SiXa-0 (wherein, n is an integer of 1 to 3, and R is alkyl, aryl, alkenyl, or m combinations thereof). represents a group, and these groups may have a functional group such as halogen, amine, hydroxy, alkoxy, aryloxy, thiol, etc.

X bar 0) 1, -〇R2, -0Ac, -o-N-c,
-cI! , -Br, -I, etc., where R2
, R3 represents the same as R above, R2 and R3 may be the same or different, and ^C represents an acetyl group).

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), si(OMe)3]2
, vinyltriethoxysilane, CR(CH2) ssi
(OMe) 1, CH*5j(O^C)s, R5(C
H2) ssi(OMe)s, vinyltris(methylethylketoxime)silane, and the like.

The silicone rubber mentioned above can be manufactured manually as a commercially available 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 [1], ■ is an integer of 2 or more, and n is an integer of 0 or 1 or more.) Such a crosslinking reaction To obtain silicone rubber, the 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(I+) octoate, cobalt naphthenate, or chloroauric acid may be used.

Additionally, fillers can 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 syi Off '23.5RX-257,5 manufactured by Toray Silicone.
There are silicone rubber dispersions for paper coating such as 14237.

In the present invention, it is preferable to use condensation and crosslinking type 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(CH2) 351
(OCH3) 3(b) H2NCE2CH2N)I
(CH2) ssi (QC)I3)z (CHs)(
C) 82N (CH2) ssi (OEt) s The silicone rubber layer used in the present invention can further contain a small amount of 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, paper covered with metal foil such as aluminum, and the like.

Among these, aluminum plates are preferred.

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

The support has a primer layer, and the primer layer includes, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer. , vinyl acetate copolymers, phenoxy resins, polyurethane resins, polycarbonate resins, polyacrylonitrile butadiene, polyvinyl acetate, and the like.

In addition, as the anchor agent constituting the primer layer,
For example, the aforementioned silane coupling agents, silicone primers, etc. 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 400 μm, preferably 100 μm.
-300 μm1 photosensitive layer 0.05-10 μm1 preferably 0.5-5 μm1 silicone rubber layer 0.1-10 μm
m, 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.

Example 1: A primer solution with the following composition was applied to a degreased aluminum plate using a bubble homogenizer disperser (pressure = 200 g/c).
m2, APv (manufactured by Manton-Gorlin),
It was coated using a wire bar coater, and then dried at 100°C for 4 minutes. The thickness of the primer layer after drying is 140
mg/d+++'. Subsequently, this primer layer was cured by irradiation for 8 seconds with a high pressure mercury lamp (I J/cm2).

[Prescription of primer at night] 100 parts by weight of 2-hydroxyethyl methacrylate/methyl methacrylate copolymer (weight average molecular weight: 40,000, charging molar ratio: 50,150) 20 parts by weight of fine zinc white (manufactured by Sakai Chemical Co., Ltd., white pigment) Get Yellow 402 (manufactured by Dainippon Ink Co., Ltd., yellow pigment) 10 parts by weight Pentaerythritol tetraacrylate 100 parts by weight DETX (manufactured by Nippon Kayaku Co., Ltd., photopolymerization initiator) 5 parts by weight EPA (manufactured by Nippon Kayaku Co., Ltd.) ), photopolymerization initiator) polyvinyl butyl ether (plasticizer) 27 parts by weight Emulsified methyl 860 parts by weight cyclohexane 100 parts by weight Next, the following photosensitive liquid was coated on the primer layer using a wire bar coater, It was dried at ℃ for 4 minutes.

The thickness of the photosensitive layer after drying is 5II1g/dI! It was 2.

[Photosensitive liquid formulation] Copolymer of 4-hydroxyphenyl methacrylamide/2-hydroxyethyl methacrylate/methyl methacrylate (weight average molecular weight/400001 molar ratio charged:
20150/30) 100 parts by weight Hexafluorophosphate of paraformaldehyde condensate of p-diazodiphenylamine 50 parts by weight Orange ■ 5 parts by weight Methyl lactate 2000 parts by weight Next, apply a silicone rubber liquid having the following composition after drying. Weight is 20
It was applied so that the concentration was mg/d11'.

[Silicone rubber liquid formulation] Dimethylpolysiloxane having hydroxyl groups at both ends (weight average molecular weight: 40,000) 100 parts by weight Triacetoxymethylsilane 10 parts by weight Dibutyltin laurate 0.8 parts by weight Isopar E (manufactured by Esso Chemical) 900 parts by weight Next, a single-sided matted polypropylene film having a thickness of 6 μm was laminated on the silicone rubber layer to prepare a sample of 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 to heat the film at 230 r.
rrJ/cta''.

The plate material obtained in this way is developed at 30°C using the following developer and the following automatic developing machine to remove the silicone rubber layer and photosensitive layer in the unexposed areas, and the halftone dots are well reproduced. A printed printing plate was obtained.

The image area of the above printing plate is made by applying a dyeing liquid of the following composition to the cloth.
After lightly rubbing the plate, it was possible to dye it vividly by washing it with water.

[Developer-1] β-anilinoethanol 0.5 parts by weight Propylene glycol 10 parts by weight p -
Tert-butylbenzoic acid 1.0 parts by weight Potassium hydroxide 1.0 parts by weight Polyoxyethylene lauryl ether 0.1 parts by weight Potassium sulfite 2.0 parts by weight Potassium metasilicate 3.0 parts by weight Water
91 parts by weight Automatic developing machine = PS plate automatic developing machine PSK-910 (manufactured by Konica Corporation) [Staining liquid Cosolfit (manufactured by Kuraray Sobren Chemical Co., Ltd., solvent)
20 parts by weight Rheodol T
W-0120 (manufactured by Kao Corporation, surfactant) 0.5 parts by weight Benzyl alcohol 5.0 parts by weight Victoria Pure Blue B OH 1.0 parts by weight Water
100 parts by weight Next, the silicone rubber area, which is the non-image area of the plate made above, was scratched using the scratch tester described below, and the degree of staining due to printing was tested under the printing test conditions shown below.

[Scratch tester] “HEIDON-19”: Manufactured by Shinto Kagaku Co., Ltd. Weight = 1
0g to 50g [Printing test] Printing machine: Diamond (Mitsubishi Heavy Industries, Ltd.) Printing ink Dry Ocolor Red (manufactured by DIC Corporation) Printing speed: 7000 rpm Meanwhile, multiple plates after development are stacked and transported on a trolley. The degree of damage to the silicone rubber in the non-image area was checked by performing a printing test in the same manner as above. The results are shown in Table 2.

Examples 2 to 13 Samples of photosensitive lithographic printing plates that do not require dampening water were prepared in the same manner as in Example, except that the plasticizer used in Example 1 was changed to those shown in Table 1. Performance was evaluated. The results obtained are shown in Table 2.

As is clear from Table 2, adding a plasticizer to the primer layer improves the scratch resistance of the silicone rubber layer.
Margin of 6 or less Table 1 shows that printing durability is also improved [Effects of the invention] The present invention contains a plasticizer in the primer layer of a photosensitive lithographic printing plate that does not require dampening water, so that when the plate is transported in layers, ,
It is possible to improve the resistance of the silicone rubber layer to scratches that occur when the surface is rubbed by dust, sand, etc. during printing, and also to improve the stiffness resistance.

Claims (1)

[Claims] A dampening water-free photosensitive lithographic printing plate having a primer layer, a photosensitive layer and a silicone rubber layer in this order on a support, characterized in that the primer layer contains a plasticizer. Lithographic printing plate.