JPH01179047A - Damping waterless photosensitive planographic master plate - Google Patents

Abstract

PURPOSE:To improve the peelability of a protective layer after image exposing by adding a specific silicone compd. to a silicone rubber layer. CONSTITUTION:The silicone compd. expressed by formula I is added to the silicone rubber layer of a damping waterless recording medium printing master plate. In formula, R1 and R2 denote an alkyl group or arom. group; R1 and R2 may be the same or different and either one thereof is an arom. group. R3 is an alkyl group of 1-4C which may be respectively the same or different. m:n=99:1-10:90mol.%. A PET film which is the protective film of the silicone rubber layer is thereby easily peeled from the silicone rubber layer and, therefore, the stable plate making is easily executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive printing original plate for a lithographic printing plate that does not require dampening water and is capable of printing without using dampening water.

[Prior art and its problems]

Conventionally, in photosensitive printing original plates for lithographic printing plates that can be printed without using dampening water (photosensitive lithographic printing plates that do not require dampening water), a photosensitive layer and a silicone rubber layer are generally placed on a support in this order. It is set in.

This silicone rubber layer generally contains a layer of silicone rubber to prevent oxygen from inhibiting the photopolymerization reaction during image exposure of the photopolymerizable photosensitive layer.
Further, a protective layer is provided for the purpose of protecting the silicone rubber layer from mechanical damage (such as scratches).

Such a protective layer requires the following performance. ■ Good oxygen barrier properties so as not to inhibit photopolymerization of the photosensitive layer; ■ Good lamination properties to the silicone rubber layer;
■Have sufficient strength with a thickness of approximately 10 μm (when removing the protective film after exposure on a large printing plate, it will not break midway and can be peeled off at -degrees), ■Between the original film and the photosensitive layer. It is required to be able to form a thin film in order to reduce the spacer effect of 2), 2) be less susceptible to the effects of outside air such as humidity, 2) have good light transmittance, and 2) be low cost. Various films that satisfy all of these conditions are known, and their inner linings are also good as protective layers.
There is polyethylene terephthalate (PET).

However, when these protective films are laminated onto a silicone rubber layer, problems arise, such as the need for a large force to peel off the film after exposure.

[Problems to be solved by the present invention]

Therefore, an object of the present invention is to provide a photosensitive lithographic printing original plate that does not require dampening water and has improved peelability of a protective layer after image exposure.

[Means to solve the problem]

In order to achieve the above object, the present inventors have made extensive studies and have developed a photosensitive printing original plate that does not require dampening water and is formed by sequentially laminating a photosensitive layer-1'-silicone rubber layer and a protective layer on a support. discovered that by adding a silicone compound represented by the following formula (I) to a silicone rubber layer, it was possible to obtain a photosensitive lithographic printing original plate that did not require dampening water and had improved releasability of the protective layer, and based on this knowledge, The present invention has been made based on this.

(In the formula, R1 and R2 are an alkyl group or an aromatic group, and R3 and R2 may be the same or different, but one of them is an aromatic group. R3 is an alkyl group having 1 to 4 carbon atoms. and each may be the same or different (m:n = 99:1 to 10:90 mol%) The photosensitive layer used in the present invention has a solubility in a developer before and after exposure. It can be anything as long as it causes a change. Image formation may be negative type or positive type.

Compounds or compositions constituting such a photosensitive layer include the following.

(A) Photopolymerizable photosensitive layer: (I) A monomer or oligomer having at least one photopolymerizable ethylenically unsaturated double bond group, (
2) A polymer compound having a film-forming ability and (3) a photopolymerization initiator is included, if necessary. Among these compositions, polymeric compounds having a film-forming ability and containing a photopolymerizable or photocrosslinkable olefinically unsaturated double bond group in the side chain to which (I) and (2) are bonded are preferred. be. Furthermore, a combination of a polymer compound containing an olefinically unsaturated double bond group in its side chain and the monomer or oligomer described in 11) above is optimal.

A polymer compound having a photopolymerizable or photocrosslinkable olefinically unsaturated double bond group in its side chain is described in JP-A-59-53836.
Allyl (meth)acrylate/(meth)acrylic acid/other addition-polymerizable vinyl monomer copolymers as required, and their alkali metal salts or amine salts; as described in Japanese Patent Publication No. 59-45979 Hydroxyethyl (meth)acrylate/(meth)acrylic acid/alkyl (meth)acrylate copolymer and its alkali metal salt or amine salt reacted with (meth)acrylic acid chloride; JP-A-59-71048 Pentaerythritol triacrylate added to a maleic anhydride copolymer by half-esterification as described in the publication, and its alkali metal salt or amine salt; styrene/
Products obtained by adding monohydroxyalkyl (meth)acrylate, polyethylene glycol mono (meth)acrylate, or polypropylene glycol mono (meth)acrylate to maleic anhydride copolymer through half-esterification, and their alkali metal salts and amine salts; ) Acrylic acid copolymers and crotonic acid copolymers in which part of the carboxylic acid is reacted with glycidyl (meth)acrylate, and their alkali metal salts and amine salts; hydroxyal, kyl (meth)acrylate copolymers, Polyvinyl formal, polyvinyl butyral reacted with maleic anhydride or itaconic anhydride, and their alkali metal salts and amine salts;
Hydroxyalkyl(meth)acrylate/(meth)
Acrylic acid copolymer reacted with 1/1 adduct of 2.4 toluene diisocyanate/hydroxyalkyl (meth)acrylate, and its alkali metal salts and amine salts; described in JP-A-59-53836 There is (
A product obtained by reacting a part of a meth)acrylic acid copolymer with allyl glycidyl ether and its alkali metal salt or amine salt; (Meth)vinyl acrylate/(meth)acrylic acid copolymer and its alkali metal salt or amine salt;
(Meth) allyl acrylate/sodium styrene sulfonate copolymer; (meth) vinyl acrylate/sodium styrene sulfonate copolymer, (meth) allyl acrylate/sodium acrylamide-1,1-dimethylethylene sulfonate copolymer , (meth)vinyl acrylate/sodium acrylamide-1,1-dimethylethylenesulfonate copolymer.

In addition, polymeric compounds with film-forming ability that can be used in the present invention include methacrylic acid copolymers, acrylic acid copolymers, crotonic acid copolymers, maleic acid copolymers, and partially esterified maleic acid copolymers. Acidic cellulose derivatives, polyvinylpyrrolidone, polyethylene oxide, alcohol-soluble nylon, polyester, unsaturated polyester, polyurethane, polystyrene, epoxy resin, phenoxy resin, polyvinyl butyral, polyvinyl formal, polyvinyl chloride, polyvinyl alcohol, partially acetalized polyvinyl alcohol , water-soluble nylon, water-soluble urethane, gelatin, water-soluble cellulose derivatives, etc.

This polymer may comprise 30 to 99% by weight, preferably 50 to 97% by weight of the total composition.

It is desirable for the photosensitive layer to be solubilized in the developer because no sludge is produced during development, and the presence of carboxylic acid in the photosensitive layer makes it difficult for the silicone rubber layer to harden.
The binder for the photosensitive layer is preferably a water-soluble carboxylic acid in the form of an alkali metal salt or amine salt.

Monomers or oligomers (I) having at least one photopolymerizable ethylenically unsaturated double bond include polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate,
Monofunctional acrylates and methacrylates such as phenoxyethyl (meth)acrylate; polyprolene glycol di(meth)acrylate, trimethylolethane tri(meth)acrylate, neopentyl glycol di(meth)acrylate;
meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, hexanediol di(meth)acrylate, trimethylolpropane tri(acryloyloxypropyl)ether, tri( (acryloyloxyethyl) isocyanurate, calcium (meth)acrylate, beryum (meth)acrylate, and polyfunctional alcohols such as glycerin and trimethylolethane that are converted into (meth)acrylates after adding ethylene oxide or propylene oxide. , urethane acrylates as described in Japanese Patent Publication No. 48-41708, Japanese Patent Publication No. 50-6034, and Japanese Patent Application Publication No. 51-37193; Polyester acrylates, epoxy acrylates prepared by reacting epoxy resin with (meth)acrylic acid, and other polyfunctional acrylates and methacrylates as described in Japanese Patent Publication No. 52-30490, U.S. Patent No. 45406
Examples include N-methylolacrylamide derivatives described in Japanese Patent No. 49.゛More゛Japan Adhesive Association Magazine V
o1. 20. fish? , pages 300-30, 8, as photocurable monomers and oligomers can also be used.

The composition ratio of these monomers or oligomers (I) to the polymer (2) is preferably in the range of 0:10 to 7:3, more preferably in the range of 1.5:8.5 to 5:5.

As the photopolymerization initiator (3), U.S. Patent No. 2.367.6
Vicinal polyketaldonyl compounds disclosed in US Pat. No. 2,367,661 and US Pat.
．． 367.670, the acilloin ethers disclosed in U.S. Pat. No. 2.448.828, U.S. Pat. No. 2.7
Aromatic acyloin compounds substituted with alpha-hydrocarbons disclosed in US Pat. No. 22.512, U.S. Patent No. 3.0
46.127 and 2.951.758, U.S. Pat. No. 3.549
．． 367, a combination of triarylimidazole dimer/p-÷mihuman earthinyl ketone, - a benzothiazole compound disclosed in U.S. Pat. No. 3,870,524, and U.S. Pat. 4.23
Benzothiazole compounds/trihalomethyl-3-triazine compounds disclosed in US Pat. No. 9.850 and acridine and phenazine compounds disclosed in US Pat. No. 3,751,259, US Pat. ．．
The photopolymerization initiators include the oxadiazole compounds disclosed in No. 212.970, and the photopolymerization initiators shown below are particularly useful. 1 as a specific photopolymerization initiator
-(4'-dodecylphenyl)-2-hydroxy-2-
Methylpropane, U, etc. can be mentioned.

These photopolymerization initiators may be used in combination, and the total amount added is 0.1 to 20% by weight, more preferably 1 to 10% by weight, based on the total composition.

In addition to the above, it is preferable to add a thermal polymerization inhibitor, such as hydroquinone, p-methoxyphenol,
Di-t-butyl-p-talesol, 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 are useful.

(B) Photodimerization type photosensitive layer: in the main chain or side chain of the polymer or to This includes those consisting of polymeric compounds containing.

Photosensitive groups such as esters, polyamides, and polycarbonates are added to the main chain or side chain of the polymer.
Those whose main component is a photosensitive polymer such as (2) such as cinnamylidenemalonic acid;
-properidene) malonic acid compounds and photosensitive polyesters derived from difunctional glycols (for example, U.S. Pat. No. 2,956,878 and U.S. Pat. No. 3,173,787). photopolymers); cinnamate esters of hydroxyl-containing polymers such as polyvinyl alcohol, starch, cellulose and the like (e.g., U.S. Pat. No. 2,690;
．． No. 966, No. 2.752,372, No. 2.73
2.301, etc.), as well as JP-A-58-25302 and JP-A-58-59-
The polymers described in Japanese Patent No. 17550 are included.

(C) A product consisting of a photocurable diazo resin or azide resin, a photosensitizer if necessary, and some filler additives: Examples of the photocurable diazo resin include: - Vara diazo diphenylamine, Vara diazo mono Examples include zinc chloride double salts of condensates of formaldehyde and diazo amines such as ethylaniline, varadiazoben, and diethylaniline.

Examples of the photocurable azide resin include azidophthalate ester of polyvinyl alcohol, azidobenzoate ester, ester of styrene-maleic anhydride copolymer, and aromatic azido alcohol such as β-(4-azidophenol)ethanol. can be given.

As the photosensitizer, filler, and additives, those mentioned in the example (I) can be used.

(D) Composition comprising an O-quinonediazide compound: A particularly preferred O-quinonediazide compound is an O-quinonediazide compound, for example, U.S. Patent No. 2.766,
No. 118, No. 2.767.092, No. 2.772
．． No. 972, No. 2.859.112, No. 2.90
No. 7.665, No. 3,046.110, No. 3.0
No. 46.111, No. 3.046.115, No. 3.
No. 046.118, No. 3.046.119, No. 3
．． 046.120, 3, 046.121, 3.046.122, 3,046.123, 3.061,430, 3.102.809,
It is described in numerous publications, including the specifications of the same No. 3.106.465, the same No. 3.635.709, and the same No. 3.647.443, and these are preferably used. Can be done. Among these, O-naphthoquinonediazide sulfonic acid ester or O-naphthoquinonediazidecarboxylic acid ester of an aromatic hydroxy compound, and O-naphthoquinonediazide sulfonic acid amide or O-naphthoquinonediazidecarboxylic acid amide of an aromatic amine compound are particularly preferred. , for example, benzoquinone-1° (?2-diazide sulfonic acid, naphthoquinone-1°2
-Ester of diazide sulfonic acid and polyhydroxyphenyl (hereinafter, ester includes partial ester) 8
, ester of naphthoquinone-1,2-diazido-4-sulfonic acid or naphthoquinone-1,2-diazido-5-sulfonic acid and pyrogallolacetone resin, benzoquinone = 1,2-diazidosulfonic acid or naphthoquinone-1 , ester of 2-diazide sulfonic acid and novolac type phenol formaldehyde resin or novolak type cresol formaldehyde resin, poly(p-aminostyrene) and naphthoquinone-1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide -5-
Amides of sulfonic acids, polyp-hydroxystyrene with naphthoquinone-1,2-diazide-4-sulfonic acid or esters of naphthoquinone-1,2-diazide-5-sulfonic acid, polyethylene glycol and naphthoquinone-1,
2-Diazido-4-sulfonic acid or naphthoquinone-1
Esters of 2-diazide-5-sulfonic acid, amides of polymeric amines and naphthoquinone-1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonic acid, polymethacrylic acid p-hydroxy Anilidonaphthoquinone-1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonic acid ester, amine-modified natural resin rosin and naphthoquinone-1,2-diazide-5- Amides of sulfonic acids, esters of naphthoquinone-1,2-diazide-5-sulfonic acid with epoxy resins from bisphenol A and propylene oxide, polymers of (meth)acrylic acid and monoesters of dihydroxyphenyl and naphthoquinone-
Esters of 1,2-diazide-4-sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonic acid, polymerized condensates of aminoisophthalic acid diallyl ester and naphthoquinonediazide sulfonic acid, and polycarbonate Quinonediazide sulfonic acid ester or quinonediazides crosslinked with isocyanate, etc., bisphenol A and naphthoquinone-1,2-diazide-4-
Sulfonic acid or naphthoquinone-1,2-diazide-5
- Esters of sulfonic acid, esters of naphthoquinone-1,2-diazide-5-sulfonic acid and phenols such as phenol and p-fresol, and alcohols such as ethyl, propyl, butyl, and amyl alcohol, naphthoquinone-1,2 -diazido-5-sulfonic acid and aniline,
Examples include acid amides with amines such as p-hydroxyaniline.

The above-mentioned photosensitive compositions include, for example, 2-methoxyethanol, 2-methoxyethyl acetate, methanol,
It is provided on a support by dissolving it in a suitable solvent such as ethanol, methyl ethyl ketone, water, etc. alone or in a mixed solvent of a suitable combination thereof. The coating amount is suitably in the range of about 0.1 g/rrr to about 10 g/m, more preferably 0.5 to 5 g/m, based on the weight after drying.

In addition, fine inorganic powders such as colloidal silica, calcium carbonate, magnesium carbonate, and iron oxide may be added as fillers. In addition, to improve the adhesion with substrates and silicone rubber layers, there are silane coupling agents described in JP-A No. 49-86130 and titanates known under the trade name Blenact sold by Ajinomoto Co., Inc. A camping agent, an aluminum coupling agent, and an organic tin compound may be added to the photosensitive layer.

In some cases, dyes or pigments may be added for the purpose of coloring the photosensitive layer, and pH indicators or leuco coloring dyes such as leuco crystal bioleft may be added as print-out agents.

As the organic tin compound, those having the following structural formula are used.

Here, R1 represents an alkyl group having 1 to 6 carbon atoms, and R2 represents an alkyl group having 1 to 20 carbon atoms. Representative organic tin compounds include, for example, diptyltin dioctanoate, dibutyltin dilaurate, dibutyltin diacetate, tin(n)octanoate, and the like.゛Aminosilane is particularly preferred as the silane cuff pulling agent.

The aminosilane referred to herein generally refers to one represented by the following formula.

RmR' nsi (OR"), -m-n (where R
: Alkyl group having unsubstituted or substituted amino group R', R' : Alkyl group or aryl group, m is 1 or 2, n is O or 1, and satisfies the relationship m+n=1 or 2. ) Typical examples include 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, bis(3-()ri) methoxysilyl)propyl]amine, bis(3-(I-rimethoxysilyl)propyl)ethylenediamine, N-(3-trimethoxysilylpropyl)morpholine, trimethoxysilylpropyldiethylenetriamine, bis(2-hydroxyethyl)aminopropyltriamine Ethoxysilane, 3-aminopropylmethyljethoxysilane, (N,N-diethyl-3-amino)propyltrimethoxysilane, (N,
N-dimethyl-3-amino)propyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N
-Phenylaminopropyltrimethoxysilane, 1-trimethoxysilyl-2-(p-aminomethyl)-phenylethane, 1-trimethoxysilyl-2-(m-aminomethyl)-phenylethane, trimethoxysilylpropyl Examples include luamine.

Further, aromatic aminosilane compounds as shown by the following structural formula are also used.

Here, n=l-3 R1: Alkyl group having 1 to 3 carbon atoms or phenyl group X: Hydrolyzable group, such as a functional group such as. Incidentally, R2 and R3 represent an alkyl group having 1 to 3 carbon atoms or a substituted alkyl group.

Reactive silane compounds having allyl isocyanurate groups are likewise used. Examples of the reactive silane compound having an allyl isocyanurate group include those represented by the following general formula.

(Here, R1 is a divalent bonding group containing at least one carbon, oxygen, nitrogen, etc., such as CJb-1C3H&NHCJa-.

R2: Alkyl group having 1 to 3 carbon atoms or phenyl group X: Hydrolyzable group, such as a functional group such as. Incidentally, R3 or R4 represents an alkyl group having 1 to 3 carbon atoms or a substituted alkyl group.

a=1-2, n=l-3) Similarly, a reactive silane compound having a ketoxime group is also used.

As the reactive silane compound having a ketoxime group, those represented by the following general formula are particularly preferred.

Here, R1, hydrogen, an alkyl group having 1 to 3 carbon atoms (e.g., methyl group, ethyl group, propyl group), 2 to 5 carbon atoms.
alkenyl group (e.g. vinyl group, allyl group), aminoalkyl group (e.g. N-β(aminoethyl)-r-
aminopropyl group, γ-aminopropyl group), aminoalkylphenylalkylene group containing an aromatic nucleus in the alkylene chain (e.g., N-β(aminoethyl)-aminomethylphenethyl group), γ-(meth)acryloxypropyl group, T-glycidoxypropyl group or T-mercaptopropyl group, R2: alkyl group having 1 to 3 carbon atoms or phenyl group, R', R,: alkyl group having 1 to 3 carbon atoms or R',
It may also be a 5- to 6-membered cycloalkane in which a portion of R' is bonded to each other.

The total amount of the organic tin compound and the silane coupling agent to be contained in the photosensitive layer is selected to be in the range of 1 to 20% by weight based on the photosensitive resin.

When the content is less than 1%, a sufficient effect in strengthening the adhesive strength cannot be obtained, and when it is more than 20%, the photosensitivity, developability, etc. of the photosensitive resin are deteriorated.

The ratio of organotin compound/silane coupling agent is 0.
A range of 2 to 5 is selected.

Outside this range, the effect of reinforcing the adhesive strength is not significant, similar to when the organic tin compound or the silane cuff pulling agent is contained alone.

The silicone rubber preferably used in the present invention is a linear or partially crosslinked polydiorganosiloxane having the following repeating units.

Here, R represents a monovalent group such as alkyl, aryl, alkenyl or a combination thereof, which has a functional group such as halogen, amine, hydroxy, alkoxy, aryloxy, (meth)acryloxy, or thiol. Good too. In addition, silicone rubber may contain fine powders of inorganic substances such as silica, calcium carbonate, and titanium oxide, adhesion aids such as silane coupling agents, titanate coupling agents, and aluminum camping agents, and photopolymerization initiators. Agents may also be added.

High molecular weight polymer whose main skeleton is the above-mentioned polysiloxane (
Polysiloxane with a molecular weight of several thousand to several hundred thousand and has a functional group at the end is used as a raw material for silicone rubber.
This is crosslinked and cured in the following manner to obtain a silicone rubber layer. Specifically, a silane crosslinking agent represented by the following general formula is mixed into the above-mentioned polysiloxane having hydroxyl groups at both ends, and if necessary, an organic metal compound such as an organic tin compound, an inorganic acid, an amine, etc. A catalyst is added and the polysiloxane and silane crosslinking agent are condensed and cured by heating or at room temperature.

R, IS I X a -n Here, n is an integer of 1 to 3, R is the same substituent as R shown above, and Here, R2 and R3 have the same meaning as R described above, and R2 and R3 may be the same or different, respectively.Ac represents an a, cetyl group.

In addition, the above-mentioned silane-based crosslinking agent can be added to the organopolysiloxane and hydrogen polysiloxane crosslinking agent having a hydroxyl group at the terminal, if necessary, and condensation curing can be carried out.

The silicone compound used in the present invention has the general formula (I)
: (In the formula, R1 and R2 are an alkyl group or an aromatic group, and R and R2 may be the same or different, but one of them is an aromatic group. R8 is a group having 1 to 4 carbon atoms. It is an alkyl group, which may be the same or different.Also, it is represented by m:n=99:1 to 10:90 mol%),
This is unreacted silicone oil. Specific examples of R1 and R2 include CH:l, CzHs
, C)l Hz.

There are Hj etc. The molecular weight MW of the silicone compound is 1×
If it is less than @lXl0', which is preferably 103 to 1 x 10h, the viscosity will be low and it will easily volatilize, while if it is larger than 1 x 10b, the viscosity will be too high and the effect as an oil will be diminished. Specific examples of particularly preferred silicone compounds include the following.

(Compound A) m:n=75:25 Mw#2xlO' (Compound B) m:n=75:25 Mw#lX10'm:n=90
:10 Mw=5X10' These silicone compounds represented by the general formula (I) may be used in combination, and the total amount added is 0.0 with respect to the entire composition of the silicone rubber layer.
The content is 1 to 10% by weight, more preferably 0.1 to 2% by weight.

If it is less than 0.01% by weight, the releasability of the protective layer will not be improved much, while if it is more than 10% by weight, the surface will become slimy due to unreacted silicone oil when used as a printing plate.

The silicone rubber layer that forms the non-image area on the printing plate is
It is also desirable that the material has excellent wear resistance, scratch resistance, and solvent resistance. For this purpose, it is best to crosslink the silicone rubber layer of the printing plate more densely than in the green plate to increase its mechanical strength. Specifically, the following (I1 to (4))
There are methods such as or a combination thereof.

(I) After exposing and developing a printing plate precursor manufactured using a silicone rubber layer consisting of a substantially linear polydiorganosiloxane having OH groups at both ends, and optionally a silicone crosslinking agent and a catalyst. The mechanical strength of the silicone rubber layer is improved by applying a silicone crosslinking agent or, if necessary, a catalyst to the non-image area of the silicone rubber layer formed on the printing plate, or by simply subjecting it to heat treatment.

(The silicone rubber layer refers to di- to tetrafunctional halogenated silanes, hydroxysilanes, alkoxysilanes, acetoxysilanes, ketoximesilanes, etc., and the catalysts include organic tin carboxylates, such as dibutyltin acetate, or titanate esters, using acetylacetone complex, chloroplatinic acid, naphthenate, etc.).

(2) A printing plate manufactured using a silicone rubber layer consisting of a substantially linear polydiorganosiloxane having an unsaturated group such as a vinyl group at the side chain or end and, if necessary, a hydrogenated silane compound or an addition catalyst. After the original plate is exposed and developed, the silicone rubber layer remaining on the plate surface is further treated with a hydrogenated silane compound or an additional catalyst, or simply subjected to heat treatment.

(2) It has the general formula n≧2, and salt platinic acid or the like is used as the addition catalyst).

(3) A printing plate precursor manufactured using a silicone rubber layer consisting of a polydiorganosiloxane having an unsaturated group such as a vinyl group or a methyl group in the side chain or terminal and a radical initiator as necessary was exposed and developed. Afterwards, if necessary, a radical initiator is further applied to the silicone rubber layer remaining on the printing plate and heat treatment is performed to strengthen the silicone rubber layer.

(Inorganic or organic peroxides can be used as radical initiators,
For example, benzoyl peroxide, silyl peroxide,
Alternatively, azobisisobutyronitrile etc. may be used).

(4) Printing plate precursor manufactured using a silicone rubber layer consisting of a substantially linear or sparsely crosslinked polydiorganosiloxane having a photoreactive group at the side chain or end and, if necessary, a photosensitizer. The silicone rubber layer in the eN light area where the eN light is exposed and developed is photo-crosslinked to become more densely crosslinked than the unexposed area and also strongly adheres to the underlying photosensitive layer. The silicone rubber layer may be further strengthened by exposing the entire surface of the printing plate obtained here with a photosensitizer, if necessary, or by simply subjecting it to heat treatment.

(Representative examples of the above photoreactive groups include (meth)acryloyl group, cinnamoyl group, maleimide group, vinyl group, allyl group, thiol group, azide group, etc.; photosensitizers include quinone type, benzophenone group, etc.) type, benzoin type, nitro compound type, etc.).

The thickness of the silicone rubber layer used in the present invention is preferably as thin as possible from the viewpoint of tone reproducibility, and a certain thickness is required from the viewpoint of rigidity resistance and printing stains, so 0.5~
Approximately 10 μm is appropriate, and usually 0.7 to 2.5 μm is desirable.

The substrate used in the present invention may be an aluminum plate, iron plate, zinc plate, etc. used for general PS plates as is, or may be subjected to caustic treatment or anodization treatment as required, or may be grained. After graining, caustic treatment or anodic oxidation treatment is used.

In addition, a polymer film may be used as the substrate; for example, a polyester film or a cellulose acetate film having good dimensional stability may be used. If a cheaper version is acceptable, it is also possible to use a water-resistant version. Laminated paper obtained by processing paper with polymer or paper laminated with aluminum foil can be used.

If necessary, a primer layer consisting of a suitable polymer may be applied; generally, the primer layer includes gelatin, casein, epoxy resin, polyvinyl formal, phenoxy resin, butyral resin, acrylic resin, polyvinyl chloride, phenolic resin, Polyurethane resin, shellac resin, etc. are used. Among these, gelatin, segaine and polyurethane are preferred.

As the gelatin used in this primer layer, so-called photographic gelatin obtained from cow bones or hide by acid treatment or alkali treatment is mainly used. In addition to this, it is also represented by the following general formula. Any gelatin, which is a natural polymeric compound condensed with various amino acids, can be used.

There are many types of amino acids that make up gelatin, and gelatin can be obtained with various compositions depending on the purification conditions, and there are also considerable differences depending on the raw materials.

The following hardeners are used to harden gelatin (that is, cross g).

(A) Inorganic hardeners chrome alum, aluminum alum, etc. (B) Organic hardeners (B-1) Aldehyde type hardeners formaldehyde, glyoxal, succinaldehyde, glutaldehyde, etc. (B-2) N-methylol and Acetal hardener (B-3) Epoxy hardener (B-4) Aziridine hardener (B-5) Mucohalogen acid hardener (B-6) Active halogen hardener (B-, ?) Dichloro -8-triazine hardener (B-8
) Active olefin hardener (B-10) Isoxazoleum salt hardener (B-11)
) Methanesulfonic acid ester hardener C) IzSOzO-
(C1(2)3-OSO□C113 etc. (B-12) Active ester hardener The amino acids in gelatin that can be used in the hardening reaction differ depending on the type of hardener used. The amino acid composition differs depending on the gelatin used.

From this, the optimal amount of hardening agent to be added varies depending on the type of gelatin used and the type of hardening agent, but gelatin 10.
It is preferable to add 1 to 200 mmol of the hardening agent, preferably 5 to 50 mol, to the 0-fold base portion.

In general, if the amount of hardener is too small, the amount of swelling will be too large, and even if dyed twice, the color will easily come off due to subsequent washing with water, etc., which is not preferable. On the other hand, since the number of moles of amino acids that can be used for the hardening reaction contained in a certain amount of gelatin is fixed, it is meaningless to add more than this number of moles of a hardening agent. has an upper limit.

The appropriate coating amount of the gelatin primer is 0.1 to 50μ, more preferably 0.5 to 10μ. Here, the coating amount is the dry film thickness after coating the gelatin primer.

Further, gelatin is preferably hardened by applying a gelatin and a hardening agent to a support, and then hardening by a conventional means such as heating.

A dye for preventing halation, a printout agent such as a trihalomethyl compound as a photoacid generator, a pH indicator, or a coco coloring dye such as leuco crystal violet may be added to the primer layer. Further, the above-mentioned silane coupling agent, titanate coupling agent, or aluminum coupling agent may be added to the primer layer for the purpose of improving the adhesion with the photosensitive layer and the metal substrate. In addition, considering the dyeability of the plate after development and plate making, a photopolymerizable monomer is added to the primer layer.
It is also effective to make the photocured exposed areas less likely to be dyed than the unexposed areas. It is also effective to add a white pigment such as Ti0z to the primer layer to improve plate inspection properties after dyeing.

The protective layer used in the present invention includes polyethylene terephthalate (PET), polyvinylidene chloride, polyvinyl chloride, a copolymer of vinyl chloride and vinylidene chloride, polyamide, cellophane, polyacrylonitrile, polysulfone, polyvinyl alcohol, polypropylene, There are plastic films such as low-density and high-density polyethylene, polystyrene, ethyl cellulose, and cellulose acetate, among which polyethylene terephthalate (PET) is the most preferred. It is possible to apply particles or to create irregularities by gravure printing.

The thickness of the protective layer used in the present invention is preferably as thin as possible from the viewpoint of tone reproducibility, and a certain thickness is required from the viewpoint of strength and oxygen barrier properties, so 2 to 20 μm is appropriate. The thickness is more preferably 5 to 12 μm.

The photosensitive lithographic printing plate that does not require dampening water according to the present invention is exposed through a transparent original image, and then developed with water or a water-based developer that dissolves the photosensitive layer in the image area. The main silicone rubber layer in contact with is removed to obtain a lithographic printing plate that does not require dampening water.

In a water-based developer, an organic solvent having a solubility in water of 10% by weight or less at room temperature, such as benzyl alcohol or phenyl cellosolve, is added to the solution in an amount of 10% by weight or less, and to this, a nonionic surfactant or an anionic solvent of 10% by weight or less is added. A surfactant and, in some cases, a cationic surfactant is added to increase the oil sensitivity of the image area, and the water content is 8.
The content should be 0% by weight or more.

Developing is done by rubbing with a vat containing the developer mentioned above,
This can be done by a known method such as immersion in a developer and then rubbing with a developer brush. At this time, the temperature of the developer may be increased to 50 to 60° C. in order to increase the development speed. As a result, the silicone rubber layer and photosensitive layer in the image area are removed, and the surface of the substrate or primer layer is exposed, and that area becomes an ink receiving area.

The dampening water-free planographic printing plate obtained by developing the dampening water-free planographic printing plate of the present invention can be dyed with a staining solution after development. The staining solution used here is the image area,
It is necessary to selectively dye the exposed primer layer and hardly dye the silicone rubber layer in the non-image areas.

Specifically, dyes such as basic dyes, acid dyes, and disperse dyes that have the property of dyeing gelatin are dissolved or dispersed in water or a particularly polar organic solvent such as alcohol. .

In order to improve dyeability, it is also effective to add surfactants and other dyeing aids to carboxylic acids and amines.

As mentioned above, it is easier to design the developer and staining solution if the developing process and dyeing process are separated, but if the developer is one that causes the primer layer to swell to some extent, it is better to include a dye in the developer. It is also possible to carry out development and dyeing at the same time.

〔Effect of the invention〕

According to the present invention, since the PET film serving as a protective film is easily peeled from the silicone rubber layer of the photosensitive lithographic printing plate that does not require dampening water, stable plate making can be easily performed.

<Example> Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 3 The following pliers composition was applied to a smooth aluminum plate degreased in a conventional manner to a dry weight of 8.0 g/rrl, and heated at 120°C for 2 minutes to dry and harden it. .

After drying the composition for the primer layer, it was kept at room temperature of about 20° C. for 4 days to sufficiently harden the film.

The following photosensitive composition was applied on the aluminum plate coated with the above primer layer in a dry weight of 1. It was coated to give a coating weight of Og/m' and dried at 100°C for 1 minute.

Photosensitive Composition Next, the following silicone rubber composition was coated on the photosensitive layer at a dry weight of 2.0 g/m'' and dried to obtain a cured silicone rubber layer.

A single-sided polymerized PET film having a thickness of 6.5 μm was laminated on the surface of the silicone rubber layer obtained as described above to obtain a photosensitive lithographic printing original plate requiring no dampening water. Exposure was done using the printer FT26V2tJPNS manufactured by Nuark, USA.
(Light source: 2KV/metal halide lamp) distance 1m
After 100 counts, the 〇 plate was cut into 1 cm x 10 cm, and the releasability of the PET film was measured using a strain gauge.

Table 1 Experiments in Table 1; 2 After image exposure of the original plate used, PE
When the T film was peeled off, immersed in an aqueous developer having the composition shown below for 1 minute, and rubbed with a development pad for 1 to 2 minutes, the photosensitive layer in the non-fogged areas and the silicone rubber layer thereon were removed.

When the resulting waterless plate was rubbed with the following staining solution, only the exposed portion of the primer layer, which was the image area, was stained a clear purple color.

Staining Solution Examples 4 to 6 A photosensitive primer solution having the following composition was applied onto a degreased and smooth aluminum plate with a thickness of 0.3 mm and heated at 120°C.
, dried for 1 minute. Coating weight after drying is 4 g/rd
Met.

The primer solution and the water-soluble photosensitive composition were then diluted to prepare a water-soluble photosensitive solution having the composition shown below, which was applied and dried at 100° C. for 1 minute. The dry coating weight was 1.0 g/d.

Photosensitive solution A silicone solution having the following composition was applied onto the photosensitive layer and dried at 120° C. for 1 minute. The dry coating weight is 1.
It was 25g/m.

PET films were laminated in the same manner as in silicone solution Examples 1 to 3, exposed to light, and peelability was measured.

Table 2 As shown in Table 1.2, the general formula (
By adding the unreacted silicone oil (I), a photosensitive lithographic printing original plate, which does not require dampening water, and which has excellent releasability of the PET film was obtained.

In addition, polyvinyl alcohol (PVA) is used as a protective layer.
Similar effects were obtained when using polyvinyrizo 7 chloride (PVDC), a composite film of polypropylene and PVDC, a composite film of nylon and PVDC, and the like. However, in the case of a composite film, it is preferable to laminate so that the PVDC surface meets the silicone rubber layer.

Procedural amendment 20 Title of the invention Photosensitive lithographic printing original plate that does not require dampening water 4,
Agent 6, subject of amendment Correct the structural formula in column 1 of the detailed description of the invention in the specification, line 2 on page 16 of the specification, to read “ ”.

2. The structural formula of a) on page 52, line 7 of the same book is ” I am corrected.

3. The structural formula of C) in the second line from the bottom of page 52 of the same book is ” I am corrected.

Claims (1)

[Scope of Claims] In a dampening water-free photosensitive printing original plate formed by sequentially laminating a photosensitive layer, a silicone rubber layer, and a protective layer on a support, the silicone rubber layer is formed by the following general formula (I). A photosensitive lithographic printing original plate that does not require dampening water and is characterized by adding the silicone compound shown below. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・・・・(
I) (In the formula, R_1 and R_2 are an alkyl group or an aromatic group, and R_1 and R_2 may be the same or different, but one of them is an aromatic group. R_3 has 1 carbon number
-4 alkyl groups, each of which may be the same or different. Further, m:n=99:1 to 10:90 molar ratio. )