JPH04212157A - Photosensitive planographic printing plate requiring no dampening water - Google Patents

Abstract

PURPOSE:To ensure superior adhesive property of a photosensitive layer to the substrate and to improve the scratch and printing resistances of the resulting planographic printing plate. CONSTITUTION:When a primer layer, a photosensitive layer and a silicone rubber layer are successively laminated on a substrate to obtain a photosensitive planographic printing plate requiring no dampening water, the primer layer is formed by curing a compsn. contg. polyurethane having polymerizable ethylenic unsatd. groups in the molecule and also having >=2,000mol.wt. with energy beams.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water (hereinafter referred to as waterless PS plate), and in particular to the wet state during development processing and the adhesion between the support and the photosensitive layer during printing. The present invention relates to a waterless PS plate with improved printing durability and scratch resistance.

0002

BACKGROUND OF THE INVENTION Various types of waterless PS plates having silicone rubber layers as non-image areas have already been proposed. For example, Special Publication No. 44-23042, Special Publication No. 46-1
6044, a waterless PS plate in which a photocurable or photodegradable photosensitive layer and a silicone rubber layer are laminated in this order on a substrate, JP-B No. 54-26923, JP-B No. 61-
No. 54222 discloses a waterless PS plate in which a photoadhesive or photopeelable photosensitive layer and a silicone rubber layer are laminated in this order on a substrate.

[0003] The former waterless PS is made by laminating a photocurable or photodegradable photosensitive layer and a silicone rubber layer on a substrate.
In the plate, the photosensitive layer undergoes a curing or decomposition reaction by irradiation with actinic rays, and a positive-type or negative-type printing plate is obtained as follows. In other words, the photosensitive layer in the exposed area in the case of a photocurable type, or the unexposed area in the case of a photodegradable type, is dissolved with water, alcohol, etc., and the plate surface is strongly rubbed, thereby rubbing the silicone rubber layer in the image area. The ink-receiving portion of the substrate is exposed to form a positive or negative printing plate. However, this plate-making method has the following drawbacks. That is, since the adhesion between the photosensitive layer and the substrate is not perfect, a serious problem arises in that even the photosensitive layer in the non-image area, which should be adhered to the substrate, peels off from the substrate.

[0004] The latter waterless PS is made by laminating a photoadhesive or photopeelable photosensitive layer and a silicone rubber layer on a substrate.
In the printing plate, by utilizing the fact that the adhesive force between the photosensitive layer and the silicone rubber layer changes due to exposure to light, the photosensitive layer is not substantially dissolved (only partially dissolved), and the photosensitive layer and/or the silicone rubber layer is dissolved. Using a developer that swells the rubber layer,
By selectively peeling off and removing the silicone rubber layer in the unexposed or exposed areas, the exposed photosensitive layer is used as an ink receiving area. However, in this case as well, since the adhesion between the photosensitive layer and the substrate is not perfect, a part of the exposed photosensitive layer peels off from the substrate during development or printing, and as a result, the substrate is exposed and the surface of the photosensitive layer or the substrate is ink-receiving. As a result, differences in ink receptivity occur, resulting in uneven ink ink application, resulting in the problem that satisfactory printed matter cannot be obtained.

As an attempt to improve the adhesion between the support and the photosensitive layer, it is known to interpose a primer layer containing an epoxy resin as a component (Japanese Patent Publication No. 61-5
No. 4219). However, although this primer layer has good adhesion to the support, it has the disadvantage that adhesion to the photosensitive layer is largely dependent on the components of the photosensitive layer. For example, when the components of the photosensitive layer are changed in an attempt to improve printing durability, scratch resistance, sensitivity, fine line reproducibility, etc., there is a problem in that the adhesion between the primer layer and the photosensitive layer decreases.

[0006] Furthermore, scratch resistance is greatly affected by the flexibility of the primer layer as well as the flexibility of the photosensitive layer. In this respect as well, a primer layer that is more flexible than epoxy resin has been desired. Furthermore, regarding a waterless PS plate using a photoreleasable photosensitive layer, it is known that a rubber component is used in the primer layer, and the rubber component is a polyurethane resin (JP-A-61-163343).
. However, this method still had the problem of insufficient adhesion to the support.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a waterless PS plate having a novel highly flexible primer layer with improved adhesion between the support and the photosensitive layer. be.

[0008]

[Means for Solving the Problems] An object of the present invention is to provide a waterless PS plate in which a primer layer, a photosensitive layer, and a silicone rubber layer are laminated in this order on a support, in which the primer layer is polymerized in the molecule. This is achieved by a waterless PS plate characterized in that it is a layer formed by curing a composition containing a polyurethane with a molecular weight of 2000 or more and having possible ethylenically unsaturated groups using energy rays. In a preferred embodiment of the present invention, the primer layer contains a photopolymerization initiator and is a layer cured by energy rays having a wavelength shorter than 450 nm, or a layer cured by electron beams.

The waterless PS plate of the present invention will be explained in detail below. <Support> The support must be flexible enough to be set in a normal lithographic printing machine, etc., and must be able to withstand the load applied during printing. Typical examples include metal plates such as aluminum, copper, and steel, plastic films or sheets such as polyethylene terephthalate, coated paper, and rubber.

It is also possible to use a composite support, a support with rubber elasticity, a support with a rubber elastic layer, and a cylindrical support. Preferred supports include aluminum plates, paper and plastic films laminated with aluminum foil on the surface. The aluminum plate used in the present invention is a plate-shaped body such as pure aluminum or an aluminum alloy containing aluminum as a main component and a trace amount of foreign atoms. These foreign atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of these foreign atoms is at most 10% by weight or less. Aluminum suitable for the present invention is pure aluminum, but since completely pure aluminum is difficult to produce due to scouring technology, it is preferable to use aluminum with as low a content of foreign atoms as possible. Further, any aluminum alloy having the above-mentioned content can be said to be a material that can be used in the present invention. The composition of the aluminum plate applied to the present invention is not specified, and conventionally known and publicly used materials can be used as appropriate. The appropriate thickness of the aluminum plate used in the present invention is approximately 0.1 mm to 0.5 mm.

[0011] If desired, such an aluminum plate may be
In order to remove the rolling oil on the surface, it is degreased by treatment with, for example, a surfactant or an alkaline aqueous solution. The aluminum plate thus degreased may be subjected to anodic oxidation treatment and/or hydrophilization treatment, if desired. As a hydrophilic treatment,
Treatment with aqueous alkali metal silicate solutions or application of colloidal silica sol is preferred. After the treatment with aqueous alkali metal silicate solution, colloidal silica sol may be applied.

[0012] Furthermore, by surface treating the support with various silane coupling agents, the adhesion with the primer layer can be further improved. As a treatment method, it is common to use a silane coupling agent in an aqueous solution of 0.1 to 3% by weight, but even higher concentrations are acceptable, and the type of silane coupling agent and treatment time are acceptable. In some cases, sufficient improvement in adhesion is observed even at lower concentrations. The appropriate coating amount of the silane coupling agent is 5 mg/m2 to 100 mg/m2 in terms of dry weight. <Primer layer> The urethane acrylate or urethane methacrylate used in the primer layer of the present invention is composed of an isocyanate compound having two or three or more isocyanate groups and a polymerizable acrylic (or methacrylic) acid ester having a hydroxyl group. A compound obtained by reacting with a known method,
The molecular weight is 2000 or more.

[0013] When the molecular weight is less than 2000, the primer layer becomes extremely hard after being cured by energy rays, causing a problem in scratch resistance. The primer layer used in the present invention is based on the pencil hardness method (JIS
As a result of measurement using H8602 (described in H8602), it is more flexible than H. Isocyanate compounds include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hexamethylene diisocyanate, morpholine diisocyanate, diphenyl ether diisocyanate, lysine diisocyanate, isophorone diisocyanate,

[0014]

[Chemical formula 1]

[0015] etc. Alternatively, these isocyanate compounds and the following polyols may be reacted in a ratio such that isocyanate groups remain. Polyols include polyethylene glycol, polyester diol, polyether ester diol, ethylene glycol, diethylene glycol, neopentyl glycol, polypropylene glycol, polybutylene glycol, triethylene glycol, hexamethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, and polyurethane. There are polyols, unsaturated polyester polyols, etc.

Examples of polymerizable acrylic (or methacrylic) acid esters having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and polyethylene glycol. Mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, polyester glycol mono(meth)
Examples include acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, an adduct of 4 moles of glycidyl methacrylate with 1 mole of xylylene diamine, and a (meth)acrylic acid adduct of an epoxy compound.

[0017] A polymerizable monomer that is compatible with the urethane acrylate or urethane methacrylate described above may be added to the primer layer used in the present invention. Examples of such monomers include styrene, acrylic acid ester, and methacrylic acid. Polyfunctional unsaturated monomers such as ester, vinyl ester, trimethylolpropane triacrylate, hexanediol diacrylate, carbitol acrylate, triethylene glycol diacrylate, pentaerythritol tetraacrylate, trimethylolpropane triethoxy triacrylate, etc. are used. The amount of these polyfunctional unsaturated monomers added is 50
It is desirable that the amount is less than % by weight.

The primer layer used in the present invention contains natural rubber, polybutadiene rubber, styrene-butadiene copolymer, nitrile rubber, acrylic rubber, butyl rubber, polyurethane, as a binder having film-forming ability.
polyester, polyamide, epoxy resin, urea resin,
It may also contain phenol resin, melamine resin, etc. In a preferred embodiment of the present invention, the photopolymerization initiator used in the primer layer includes benzoin ether type,
Known photopolymerization initiators such as benzophenone, ketal, acetophenone, and thioxanthone can be used.

For example, benzophenone, Michler's ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, α-methylolbenzoin,
α-methylolbenzoin isomethyl ether, α-methoxybenzoin ether, benzoin phenyl ether, α-t-butylbenzoin, 2,2-dimethoxyphenylacetophenone, 2,2-diethoxyphenylacetophenone, 2,2-diethoxyacetophenone, Benzyl, pivaloin, anthraquinone, benzanthraquinone, 2-ethyl anthraquinone, 2-chloroanthraquinone, hydroxycyclohexylphenyl ketone,
α-Hydroxyisobutylphenone, chlorothioxanthone, 3,3-dimethyl-4-methoxybenzophenone, 2,4-diethylthioxanthone, 1-hydroxycyclohexylphenylketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino -1-propane and the like can be mentioned.

In the present invention, it is also preferable to use a photopolymerization accelerator (dimethylaminoethanol, p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, etc.) together with the photopolymerization initiator. In the primer layer of the present invention, the amount of the photopolymerization initiator is preferably 0.05 to 1.0 parts by weight, more preferably 0.1 to 0.5 parts by weight, based on 10 parts by weight of urethane acrylate or urethane methacrylate. The photopolymerization accelerator is preferably 0.1 to 0.5 parts by weight.

In order to further improve the adhesive strength between the primer layer of the present invention and the substrate, a diazonium salt polycondensation product as described in Japanese Patent Application No. 2-21072 is added to urethane acrylate or urethane methacrylate. It may be added in an amount of 0.1% to 20% by weight, preferably 0.5% to 10% by weight. In addition, dyes and pigments as antihalation agents, TiO for whitening
2. Fading dyes and color-forming dyes as printing-out imparting agents;
A silicone surfactant or a fluorine surfactant may be added.

The above composition is dissolved in a suitable solvent, applied onto a support, dried, exposed to actinic rays or irradiated with electron beams, and cured to form the primer layer of the present invention. Although the light source used for photocuring in the present invention is not particularly limited, a high-pressure mercury lamp or the like can be used. Further, the irradiation device for curing the electron beam is not particularly limited, but a scanning type, a non-scanning type (curtain method), etc. are used.

The coating amount of the primer layer of the present invention is suitably 1 to 50 g/m 2 in terms of dry weight. <Photosensitive layer> The photosensitive layer used in the present invention generally has a solubility in a developer that differs depending on exposure, or a change in adhesiveness at the interface with the upper silicone rubber layer. Any material can be used, preferably a photopolymerizable photosensitive material, a) a photopolymerizable monomer or oligomer made of an ethylenically unsaturated monomer or oligomer having a boiling point of 100° C. or higher; and (a) a photopolymerization initiator. , and c) contains a binder made of a polymer compound.

Each component will be explained below. b) Photopolymerizable monomer or oligomer Typical examples of photopolymerizable monomers or oligomers include carbon atoms of 30
(Meth)acrylic esters with a boiling point of 100°C or higher, derived from the following monohydric alcohols or monovalent amines, or (meth)acrylamide, polyhydric alcohols or polyhydric amines with a carbon number of 80 or less Examples include (meth)acrylic acid ester or (meth)acrylamide having a boiling point of 100°C or higher.

Next, representative monomers useful in the present invention will be listed. Some of these can also be used as raw materials for oligomers useful in the present invention. (i-i) (meth)acrylic acid esters of the following alcohols methanol, ethanol, propanol,
Pentanol, cyclohexanol, octanol, undecanol, norbornyl alcohol, polymethylene glycol, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, trimethylolmethane, pentaerythritol (i-ii) (meth)glycidyl acrylate For example, esters and adducts of hydrogen halides, amines, carboxylic acids, etc., ring-opened polymers of glycidyl groups, etc.

[0026]

[Case 2]

(I-iii) The following (meta)
Acrylamide derivatives (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, methylenebis(meth)acrylamide, hexamethylenebis(meth)acrylamide, diacetone acrylamide, hydroxymethyldiacetone acrylamide.

The most useful monomers that can be used in the photopolymerizable photosensitive material of the present invention include the following. Ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate,
Trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate Acrylate Photopolymerization Initiator Typical examples of photopolymerization initiators that can be used in the present invention include the following. (ro-i)
Benzophenone derivatives, such as benzophenone, Michler's ketone, xanthone, anthrone, thioxanthone, acridone, 2-chloroacridone, 2-chloro-
N-n-butyl acrylate, etc. (ro-ii) Benzoin derivatives, such as benzoin, benzoin methyl ether, benzoin ethyl ether, etc. (ro-iii) Quinones, such as p-benzoquinone, β-naphthoquinone, β-methylanthraquinone, etc. (ro-iii) -iv) sulfur compounds, such as dibenzyl disulfide, di-n-
(rho-v)azo or diazo compounds such as butyl disulfide, such as 2-azo-bis-isobutyronitrile, 1-azo-bis-1-cyclohexanecarbonitrile, p-diazobenzylethylaniline, Congo red, etc. -vi) Halogen compounds, such as carbon tetrabromide, silver bromide, α-chloromethylnaphthalene, trihalomethyl-S-triazine compounds, etc. (lo-vii) Peroxides, such as benzoyl peroxide, etc. (lo-viii)
) Uranyl salts such as uranyl nitrate c) Binder made of a polymeric compound As the binder made of a polymeric compound, any solvent-soluble resin that can form a film at room temperature can be used. For example, polyamide resin, acrylic resin,
Although polyurethane resins, polyester resins, etc. can be used, polyurethane resins are particularly preferred. This is because intermolecular hydrogen bonding due to urethane bonds and urea bonds can be expected between the primer layer and the photosensitive layer, and it is thought that the adhesion between the layers will become stronger.

Preferred polyurethane resins used as binders for the photosensitive layer include those derived from polyester polyols, polyether polyols, polyalcohols and polyisocyanates, and polyurethane resins derived from polyols and polyisocyanates, as well as polyurethane resins derived from polyester polyols, polyalcohols and polyisocyanates, and polyurethane resins derived from polyester polyols, those derived from polyalcohols and polyisocyanates, and polyurethane resins derived by substituting a portion of the above polyols with polyamines to extend the chain. This is a polyurethane resin containing urea bonds. Examples of polyester polyols include condensed polyester polyols, lactone polyester polyols, and polycarbonate diols. Condensation type polyester polyol is
Adipic acid and ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol,
Neopentyl glycol, trimethylolpropane, 1
, 6-hexanediol and the like.

The lactone polyester polyol is obtained, for example, by ring-opening polymerization of ε-captolactone and a diol. Polycarbonate diol is obtained, for example, by the reaction of 1,6-hexanediol and ethylene carbonate. A polyether polyol can be obtained by reacting an initiator having active hydrogen with an alkylene oxide, and propylene oxide or ethylene oxide can be used as the alkylene oxide.

[0031] Polyalcohols include ethylene glycol, diethylene glycol, propylene glycol,
Examples include 1,4-butanediol, neopentyl glycol, trimethylolpropane, and 1,6-hexanediol. In addition, as polyisocyanate, 1,5-
Naphthalene diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, lysine diisocyanate, tetramethylxylylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8 -Diisocyanate-4-isocyanate Methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate and the like.

Examples of polyamines include diphenylmethanediamine derivatives, m-phenylenediamine derivatives, ethylenediamine, 1,4-diaminobutane, 1,6-diaminohexane, and isophoronediamine. The amount of these polyurethane resins added is suitably 10 to 90% by weight based on the total dry weight of the photosensitive layer.

In addition to the above-mentioned photopolymerizable photosensitive materials, other photosensitive materials that can be used include those whose solubility in a developing solution varies depending on exposure, or whose adhesive strength with the upper silicone rubber layer changes. Good to have. Examples of such photosensitive materials include photosensitive materials of photodimerization type, photocurable diazo resin photosensitive materials, and photosensitive materials comprising o-quinonediazide compounds, which are described in JP-A No. 62-50760.

Additives may be added to the photosensitive layer depending on the purpose. For example, hydroquinone, p-
Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis(3-methyl-6-t-butylphenol), 2,2'-methylenebis(4-methyl -6
-t-butylphenol), 2-mercaptobenzimidazole, and the like. Further, dyes or pigments may be added for the purpose of coloring the photosensitive layer, and pH indicators, leuco dyes, and fading dyes may be added as print-out agents. Further, a small amount of silicone compounds such as polydimethylsiloxane, methylstyrene-modified polydimethylsiloxane, olefin-modified polydimethylsiloxane, silane coupling agent, silicone diacrylate, silicone dimethacrylate, etc. may be added to the photosensitive layer. Furthermore, a fluorosurfactant may be added to improve coating suitability. Furthermore, in order to strengthen the adhesion with the silicone rubber layer if necessary, silica powder or hydrophobic silica powder whose surface has been treated with a (meth)acryloyl group or allyl group-containing silane coupling agent is added to the entire photosensitive layer composition. It may be added in a layer of 50% by weight or less. As other additives, epoxy resins, ketone resins, melamine resins, alkyd resins, vinyl acetate copolymers, vinyl chloride copolymers, and diazonium salt polycondensates may be added.

The photosensitive layer composition as described above can be prepared using a suitable compound such as 2-methoxyethanol, 2-methoxyethyl acetate, methyl lactate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methanol, ethanol, methyl ethyl ketone, water, etc. Approximately 0.1 to 20 g after drying when dissolved in a solvent alone or a mixed solvent of an appropriate combination of these solvents
The primer layer is coated on the primer layer at a coating weight of 0.5 to 10 g/m2, preferably 0.5 to 10 g/m2, and dried. <Silicone Rubber Layer> The silicone rubber layer preferably used in the present invention is a linear or partially crosslinked polydiorganosiloxane, and has the following repeating units.

-(Si(R)2-O)- Here, R represents an alkyl group, an aryl group, an alkenyl group, or a combination of these monovalent groups, and these include a halogen atom, an amino group, a hydroxy group, , an alkoxy group, an aryloxy group, a (meth)acryloxy group, a thiol group, or the like. In addition, the silicone rubber may contain fine powders of inorganic substances such as silica, calcium carbonate, and titanium oxide, adhesion aids such as the silane coupling agents, titanate coupling agents, and aluminum coupling agents, and light. A polymerization initiator may also be added.

Polysiloxane having a molecular weight of several thousand to several hundred thousand and having a functional group at the end is used as a raw material for the above-mentioned high molecular weight polymer (silicone rubber) whose main skeleton is polysiloxane. A silicone rubber layer is obtained by crosslinking and curing in a method. Specifically, a silane crosslinking agent represented by the following general formula is mixed into the polysiloxane having a hydroxyl group at both ends or only at one end, and if necessary, an organometallic compound such as an organotin compound is added. A catalyst such as an inorganic acid or an amine is added, and the polysiloxane and the silane crosslinking agent are heated or condensed and cured at room temperature.

RnSiX4-n Here, n is an integer of 1 to 3, R is the same substituent as R shown above, and X is -OH, -OR2, -OAc, O
-N=represents a substituent such as CR2R3, -Cl, -Br, -I, etc. Here, R2 and R3 are R
has the same meaning, and R2 and R3 may be the same or different. Moreover, Ac represents an acetyl group.

Other organopolysiloxanes and hydrogenpolysiloxanes having a hydroxyl group at the terminals are condensed and cured by combining the crosslinking agent with the above silane crosslinking agent. In addition, an addition type silicone layer crosslinked by an addition reaction between a ≡SiH group and a -CH=CH- group is also useful. The addition-type silicone rubber layer has the advantage that it is relatively unaffected by humidity during curing, can be crosslinked at high speed, and can easily obtain a silicone rubber layer with constant physical properties. The addition-type silicone rubber layer used here is obtained by the reaction of a polyvalent hydrogen organopolysiloxane with a polysiloxane compound having two or more -CH=CH- bonds in one molecule, and preferably contains the following: Components: (1) 100 parts by weight of an organopolysiloxane having at least two alkenyl groups (more preferably vinyl groups) directly bonded to silicon atoms in one molecule (2) At least two ≡SiH bonds in one molecule
Organohydrogenpolysiloxane

0.1-1000 parts by weight (3)
addition catalyst
It is obtained by crosslinking and curing a composition consisting of 0.00001 to 10 parts by weight. Ingredient (1)
The alkenyl group may be located either at the end or in the middle of the molecular chain, and preferred organic groups other than the alkenyl group are substituted or unsubstituted alkyl groups and aryl groups. Component (1) may have a trace amount of hydroxyl group. Component (2) reacts with component (1) to form a silicone rubber layer, but also plays the role of imparting adhesiveness to the photosensitive layer. The hydrogen group in component (2) may be located either at the end or in the middle of the molecular chain, and the organic groups other than hydrogen are selected from the same ones as in component (1). The organic groups of component (1) and component (2) account for 60% of the total number of bases in terms of improving ink repellency.
It is preferable that the above group is a methyl group. The molecular structure of component (1) and component (2) may be linear, cyclic, or branched, and the molecular weight of at least one of them is 1,000.
It is preferable from the viewpoint of rubber physical properties that the component (1
) preferably has a molecular weight of more than 1,000.

Examples of component (1) include α,ω-divinylpolydimethylsiloxane, (methylvinylsiloxane)(dimethylsiloxane) copolymer having methyl groups at both ends, and component (2), which has methyl groups at both ends. Examples include polydimethylsiloxane having hydrogen groups, α,ω-dimethylpolymethylhydrogensiloxane, (methylhydrogensiloxane)(dimethylsiloxane) copolymer having methyl groups at both ends, and cyclic polymethylhydrogensiloxane.

Component (3) The addition catalyst in (3) can be arbitrarily selected from known ones, but platinum-based compounds are particularly preferred, and platinum alone, platinum chloride, chloroplatinic acid, olefin-coordinated platinum, etc. Illustrated. For the purpose of controlling the cure rate of these compositions, tetracyclo(methylvinyl)
Organopolysiloxanes containing vinyl groups such as siloxane, alcohols containing carbon-carbon triple bonds, acetone,
It is also possible to add crosslinking inhibitors such as methyl ethyl ketone, methanol, ethanol, propylene glycol monomethyl ether.

[0042] These compositions undergo an addition reaction and begin curing when the three components are mixed, but the curing rate is characterized by rapidly increasing as the reaction temperature increases. Therefore, the pot life until rubberization of the composition is extended,
In addition, in order to shorten the curing time on the photosensitive layer, the curing conditions of the composition should be within a temperature range that does not change the characteristics of the support and photosensitive layer, and the composition should be maintained at a high temperature until completely cured. is preferable from the viewpoint of stability of adhesive force with the photosensitive layer.

In addition to these compositions, known adhesion promoters such as alkenyltrialkoxysilanes may be added, and organopolysiloxanes containing hydroxyl groups, which are the compositions of the condensed silicone rubber layer, and hydrolyzable functional group-containing It is also optional to add silane (or siloxane),
Further, for the purpose of improving rubber strength, it is also optional to add a known filler such as silica.

[0044] The silicone rubber layer in the present invention serves as a printing ink repellent layer, and if the thickness is small, there will be problems such as a decrease in ink repellency and the possibility of scratches; if the thickness is large, developability will be poor. In view of this, the thickness is preferably 0.5 μm to 5 μm. In the waterless PS plate described here, it is optional to coat various silicone rubber layers on top of the silicone rubber layer. For the purpose of preventing poisoning of the catalyst in the rubber composition, an adhesive layer may optionally be provided between the photosensitive layer and the silicone rubber layer. A transparent film is placed on the silicone rubber layer to protect the surface of the silicone rubber layer.
For example, it may be laminated with polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc., or coated with a polymer. Furthermore, the surface of the transparent film provided on the silicone rubber layer on the side opposite to the silicone rubber layer can be matted, and in this case, the one described in European Patent No. 130222B is particularly preferred.

After the waterless PS plate according to the present invention is exposed through the original image, a developer capable of dissolving or swelling a part or all of the photosensitive layer in the image area, or a developer capable of swelling the silicone rubber layer is used. It is developed with In this case, part of the photosensitive layer in the image area and the silicone rubber layer thereon may be removed, or only the silicone rubber layer in the image area may be removed, and this can be controlled by the strength of the developer. .

As the developing solution used in the present invention, those known as developing solutions for waterless PS plates can be used. For example, aliphatic hydrocarbons [hexane, heptane,
Isopar E, H, G” (trade name of aliphatic hydrocarbons manufactured by Esso Chemical Co., Ltd.) or gasoline, kerosene, etc.),
Aromatic hydrocarbons (toluene, xylene, etc.) or halogenated hydrocarbons (triclene, etc.) to which the following polar solvents are added can be used.・Alcohols (methanol, ethanol, propanol, benzyl alcohol, ethylene glycol monophenyl ether,
2-methoxyethanol, 2-ethoxyethanol, carbitol monoethyl ether, carbitol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, propylene glycol, polypropylene glycol, triethylene glycol, tetraethylene glycol), ketones (acetone, methyl ethyl ketone), esters (ethyl acetate, methyl lactate, ethyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, carbitol acetate, dimethyl phthalate) , diethyl phthalate) Particularly preferred developing solutions include those containing 0.1 to 100% by weight of propylene oxide derivatives having an average molecular weight of 100 to 1,000, as described in Japanese Patent Publication No. 63-21890, and It is an aqueous developer containing ethylene glycol monoalkyl ether or diethylene glycol monoalkyl ether (herein, the alkyl group has 5 to 8 carbon atoms) as described in No. 1-139558.

During development, the silicone rubber layer in the image area is removed by, for example, rubbing the plate surface with a developing pad containing a developer as described above, and the photosensitive layer is exposed, which becomes an ink receiving area. Further, according to the method described in Japanese Patent Publication No. 63-33140, a part or all of the photosensitive layer in the image area is eluted using a processing liquid capable of dissolving at least a part of the photosensitive layer in the image area, and then the silicone rubber A developing method in which the silicone rubber layer in the image area is peeled off by rubbing the printing plate in the presence of water or a solvent containing water as a main component that does not have the effect of swelling the layer can also be applied. In this case, it is preferable to develop using the method described in JP-A-63-163357 or an automatic developing machine using that method.

In order to confirm the image forming properties of the thus obtained printing plate, the exposed image area (photosensitive layer) is stained with a staining solution and the plate is inspected. By impregnating a soft pad with the staining solution and lightly rubbing the image area, only the exposed image area of the photosensitive layer is dyed, thereby confirming that the development has been sufficiently performed to the highlight area. The dyeing solution is one or more selected from water-soluble disperse dyes, acidic dyes and basic dyes, mixed with water, alcohols, ketones,
It may be used alone or dissolved or dispersed in a mixed solution of two or more of ethers and the like. In order to improve dyeability, it is also effective to add carboxylic acids, amines, surfactants, dyeing aids, etc.

[0049]

Effects of the Invention: The waterless PS plate of the present invention has dramatically improved adhesion strength between the support and the primer layer, and between the primer layer and the photosensitive layer, and even after image exposure and development, the above adhesion is maintained. is well maintained, showing excellent image reproducibility, and
The obtained lithographic printing plate has excellent scratch resistance and printing durability. Note that % indicates weight % unless otherwise specified.

[0050]

[Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples. Example 1 A primer layer having the following composition was coated on a smooth aluminum plate degreased in a conventional manner to a dry weight of 4 g/m2, dried at 100°C for 2 minutes, and heated using a high-pressure mercury lamp (output 80 W/cm). ) was exposed and cured.

Primer layer composition Goselac UV2000B (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.)
Urethane acrylate resin molecular weight 17000) 10 parts by weight
trimethylolpropane tri
8 parts by weight
Ethoxytriacrylate
2,4-diethylthioxanthone
0.4 parts by weight p-dimethylaminobenzoic acid

0.4 parts by weight Ethyl ester Titanium oxide

0.12 parts by weight methyl ethyl ketone
30 parts by weight
propylene glycol mono
20 parts by weight methyl ether
Fluorine surfactant
0.01
Part by weight On this exposed primer layer, the following photosensitive layer composition was applied to a dry weight of 3 g/m2, and 1
It was dried at 00°C for 1 minute.

Photosensitive layer composition Crisbon 3006LV

5 parts by weight (Polyurethane rubber manufactured by Dainippon Ink and Chemicals Co., Ltd.)
30% toluene, ethyl acetate, dimethyl
Formamide solution) xylylene diamine 1 mol/Gly
0.6 parts by weight
Sidyl methacrylate 4 mole adduct
Polyethylene glycol (molecular weight
0.4 parts by weight
400) Diacrylate
ethyl michler's ketone
0.2
Parts by weight Dimethylthioxanthone

0.1 part by weight Victoria Pure Blue
0.005 parts by weight
BOH naphthalene sulfonate
Fluorine surfactant
0
．． 01 parts by weight Methyl ethyl ketone
10 parts by weight
Propylene glycol
10 parts by weight of monomethyl ether Next, the following silicone rubber composition liquid was coated on the above photosensitive layer to give a dry weight of 2.0 g/m2, and heated at 140°C for 2.0 g/m2.
It was dried for a minute to obtain a silicone rubber layer.

Silicone rubber layer composition α,ω-divinylpolydimethylsiloxane 9 parts by weight
(degree of polymerization approximately 700)
(CH3)3-Si-O-(Si(CH3)2-O)
30-(SiHCH3-O)10-Si(CH3)3
1 part by weight polydimethylsiloxane
0.5 parts by weight
(Polymerization degree approximately 8,000) Olefin-chloroplatinic acid catalyst solution
0.2 parts by weight
inhibitor

0.15 parts by weight Isopar G

140 parts by weight
(Manufactured by Esso Chemical Co., Ltd.: Petroleum-based solvent) A biaxially oriented polypropylene film with a thickness of 9 μm on one side, matted on one side, was placed on the surface of the silicone rubber layer obtained as above, with the non-matted side being the silicone rubber layer. They were laminated so that they were in contact with each other to obtain a waterless PS plate.

[0054] A 200 lines/inch dot positive film was overlaid on this PS plate, and FT26IV UDN manufactured by Nuark was used.
S ULTRA-PLUS FLIPTOP PLAT
After 30 counts of exposure in a vacuum using an E MAKER exposure machine, the laminate film was peeled off and immersed in a 40° C. solution of tripropylene glycol for 1 minute. Thereafter, the silicone rubber layer in the unexposed areas was removed by rubbing with a developing pad in water, and a lithographic printing plate with excellent halftone dot reproducibility and requiring no dampening water was obtained. This printing plate had excellent adhesion between the photosensitive layer and the primer layer, and between the primer layer and the support, and neither the non-image area nor the image area peeled off from the support during development. In addition, when the above printing plate was attached to a Heidelberg GTO printing machine with the dampening water supply device removed and printed using Toyo Ink Co., Ltd.'s Aquares Five black ink, it was found that up to 50,000 sheets were printed, there were no scratches caused by handling during plate making. Excellent prints with no stains were obtained.

Comparative Example 1 Plate making and printing were carried out in the same manner as in Example 1 except that the primer layer composition of Example 1 was replaced with the one below and dried at 100°C for 2 minutes. Prints with scratches and stains were obtained after printing 5,000 sheets. Primer layer composition Epicoat 1001

10 parts by weight (Bisfe manufactured by Shell Chemical Co., Ltd.)
Nord A-based epoxy resin) Methyltetrahydrophthalic anhydride
3.6 parts by weight
2,4,6-tris(dimethyl
1.2 parts by weight
aminomethyl)phenol
Methyl ethyl ketone

30 parts by weight Propylene glycol mono
20 parts by weight
Methyl ether fluorine surfactant
0.01 part by weight Example 2 A primer layer composition having the following composition was applied and dried on the same aluminum plate as used in Example 1, and then ES
2Mra at an accelerating voltage of 150KV using an electron beam irradiation device manufactured by I (Energy Science Inc.)
It was irradiated with electron beam d and cured.

Primer layer composition Goselac UV7210B

10 parts by weight (urethane acrylate resin manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.)
molecular weight 3500) trimethylolpropanetriethoxytri
8 Parts by weight Acrylate Titanium oxide

0.12 parts by weight Methyl ethyl ketone
30 parts by weight
Propylene glycol monomethyl ether 20 parts by weight
Fluorine surfactant

0.01 part by weight A photosensitive solution made of the photodimerizable photosensitive material shown below was applied onto the primer layer irradiated with a coronal beam at a dry weight of 0.2 g/m2.
A photosensitive layer was obtained by drying at 0° C. for 35 seconds.

Photosensitive layer composition p-phenylene diacrylic acid ester and 10 parts by weight of 1,4
- Photosensitive unsaturated polyester 1-methyl-2-benzoylmethylene-β by 1:1 polycondensation with dihydroxyethyloxycyclohexane 0
．． 6 parts by weight Naphthothiazoline Sumitone Cyanine Blue VH514
2 parts by weight (phthalocyanine blue pigment manufactured by Sumitomo Chemical Co., Ltd.) Methyl ethyl ketone
300 parts by weight methyl cellosolve acetate
600 parts by weight A silicone rubber layer similar to that in Example 1 was provided on this photosensitive layer, imagewise exposed in the same manner, and the unexposed areas of the photosensitive layer and silicone rubber layer were removed by rubbing with a development pad in the following developer. A lithographic printing plate that does not require dampening water and has excellent halftone dot reproducibility was obtained. This printing plate had excellent adhesion between the photosensitive layer and the primer layer, and between the primer layer and the support, and neither the non-image area nor the image area peeled off from the support during development. Further, as a result of printing in the same manner as in Example 1, excellent printed matter without any scratches or stains was obtained even after printing 50,000 copies.

Developer composition Isopar H (Esso Chemical Co., Ltd.)
Petroleum-based solvent) 25 parts by weight Solfit (manufactured by Clarei Soprene Chemical Co., Ltd.) 25 parts by weight
methyl alcohol

25 parts by weight toluene

25 parts by weight Comparative Example 2 The primer layer composition of Example 1 was replaced with the following 14
When image exposure and development were carried out in the same manner as in Example 1 except that the plate was dried at 0° C. for 2 minutes, the primer layer peeled off from the support during development, and a satisfactory printing plate could not be obtained.

[0059] Primer layer composition

Claims (1)

[Claims] Claim 1. A dampening water-free photosensitive lithographic printing plate comprising a primer layer, a photosensitive layer, and a silicone rubber layer laminated in this order on a support, wherein the primer layer is made of a polymerizable ethylenic material in the molecule. Molecular weight 20 with unsaturated groups
1. A photosensitive lithographic printing plate that does not require dampening water and is a layer formed by curing a composition containing a polyurethane of 0.00 or more with energy rays.