JPH05297575A - Waterless planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain good printing out property for picture images and to prevent decoloration or flocculation due to long-term storage by incorporating a reaction product of triphenylmethane basic dye and specified aromatic sulfonate into a photosensitive layer. CONSTITUTION:The waterless planographic printing plate consists of a substrate and a photosensitive layer and a silicone rubber layer formed in this order on the substrate. The photosensitive layer contains a reaction product of triphenylmethane basic dye and aromatic sulfonate expressed by formula. In formula, Ar is a substd. or unsubstd. aromatic ring. The substituents are at least one kind selected from hydrogen atom, halogen atom, hydroxyl groups, etc., and may be same or different. M is an alkali metal or ammonium salt. As for the substrate used for this planographic printing plate, any material may be used as far as it gives dimensional holding property to the printing plate and endures printing. For example, polymer films, metal plates, paper or composite material of these are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing plate precursor requiring no fountain solution, and more specifically, a photosensitive layer capable of receiving ink and a silicone rubber layer capable of repelling ink are provided on a substrate. The present invention relates to a lithographic printing plate precursor that does not require dampening water and is provided in this order.

[0002]

2. Description of the Related Art Conventionally, there is known a lithographic printing original plate which does not require a fountain solution and has a silicone rubber layer as an ink repellent layer.
Japanese Patent Publication No. 44-23042, Japanese Patent Publication No. 46-16044
Issue, Japanese Examined Patent Publication No. 54-26923, Japanese Examined Patent Publication No. 61-5422
No. 2, JP-B-55-22781 and the like disclose a lithographic printing plate precursor that does not require a dampening water and has a photosensitive layer and a silicone rubber layer provided in this order on a substrate. In these printing plates, it is disclosed that a dye such as crystal violet is added to the photosensitive layer in order to impart image printability.

However, when the above-mentioned dye is added to such a photosensitive layer to impart image printability, when the printing original plate is stored for a long period of time in association with the dye structure, fading and aggregation of the dye occur. However, there is a problem that the storage stability is not good.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and it has good print-out properties and does not cause fading or aggregation of the dye even when stored for a long period of time. Another object is to provide a lithographic printing plate precursor that does not require fountain solution and has excellent storage stability.

[0005]

The object of the present invention is as follows.
In a lithographic printing plate precursor requiring no fountain solution, which comprises a photosensitive layer and a silicone rubber layer provided in this order on a substrate, the photosensitive layer comprises a triphenylmethane basic dye and an aromatic compound represented by the following general formula (I). This is achieved by a lithographic printing plate precursor that does not require a fountain solution characterized by containing a reaction product with a sulfonate.

[0006]

[Chemical 2] (In the formula, Ar represents a substituted or unsubstituted aromatic ring, and the substituent thereof is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, a mercapto group, a cyano group, a sulfonyl group, a carbon number of 1 to 20. Substituted or unsubstituted alkyl group, alkoxy group, amide group, acyloxy group, alkanoyl group, formyl group, carboxyl group, 2 to 2 carbon atoms
It is at least one selected from the group consisting of 20 substituted or unsubstituted alkenyl groups, alkenyloxy groups, substituted or unsubstituted aryl groups having 5 to 20 carbon atoms, and aryloxy groups, which may be the same or different. May be. M represents an alkali metal or ammonium salt. ) The substrate used in the lithographic printing plate precursor of the present invention may be any one as long as it imparts shape retention to the lithographic printing plate precursor and can withstand printing, a polymer film, a metal plate, paper, Alternatively, a composite material of these or the like is used.

For the purpose of improving the adhesiveness, improving the plate inspection property, and other purposes, it is possible to coat a primer layer and use it as a support. As the primer layer, epoxy resin, urea resin, benzoguanamine resin,
Menamine resins, polyester resins and the like are used alone or in combination.

The photosensitive layer used in the present invention has the following constitutions.

A photopolymerizable photosensitive layer obtained by adding a photopolymerization initiator, which comprises one or more kinds of radical-polymerizable ethylenically unsaturated bond-containing monomers, prepolymers and polymers. Here, as a monomer having a radical-polymerizable ethylenically unsaturated bond, a prepolymer, and a known polymer, any compound having an acryloyl group or a methacryloyl group having a boiling point of 100 ° C. or higher may be used, and typical examples thereof are given below. ..

(1) An acrylic acid or methacrylic acid ester of the following alcohols.

Methanol, ethanol, propanol,
Hexanol, octanole, cyclohexanol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, trimethylolpropane, Pentaerythritol, etc. (2) Reaction products of the following amines and carboxylic acids with acrylic acid glycidyl ester or methacrylic acid glycidyl ester.

Methylamine, ethylamine, butylamine, benzylamine, ethylenediamine, diethylenetriamine, hexamethylenediamine, p-xylylenediamine, m-xylylenediamine, ethanolamine,
Dimethylamine, aniline, etc.

Acetic acid, propionic acid, benzoic acid, acrylic acid, methacrylic acid, succinic acid, maleic acid, phthalic acid,
Tartaric acid, citric acid, etc.

(3) The following amide derivatives.

Acrylamide, methacrylamide, N-
Methyl acrylamide, methylene bis acrylamide, etc.

(4) A reaction product of an epoxy compound and acrylic acid or methacrylic acid.

(5) A reaction product of an isocyanate-containing compound and β-hydroxyethyl acrylate or β-hydroxyethyl methacrylate.

It is possible to use one or more of these compounds as a constituent component and, if necessary, to add an organic polymer compound which can be mixed with these compounds.

Examples of such organic polymer compounds include polymers and copolymers shown below.

(1) Acrylic acid ester, methacrylic acid ester, acrylonitrile polymers such as polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, and copolymers thereof.

(2) Unblended rubber such as polybutadiene, polyisobutylene, polychloroprene, styrene-butadiene rubber.

(3) Vinyl polymers such as polyvinyl acetate, polyvinyl alcohol, polybutyl butyral, and copolymers thereof.

(4) Polyether such as polyethylene oxide.

(5) Polyesters such as phthalic acid, isophthalic acid, maleic acid and adipic acid and ethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and the like. Reaction product.

(6) Polyurethanes such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate and 1,4-butanediol, 1,6 -Hexanediol, Polyetherpolyol of (4), (5)
The reaction product with the polyester polyol obtained in 1.

(7) Epoxy resin (8) Polyamide As a photopolymerization initiator to be added, benzoin methyl ether is used.
, Benzoin isopropyl ether, benzoin derivatives such as α, α-dimethoxy-α-phenylacetophenone, benzophenone, fluorenone, xanthone,
Thioxanthone, N-methylacridone, N-butylacridone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2,4 -Diethylthioxanthone and the like can be mentioned, but thioxanthones and acridones are particularly effective.

Photodimerization type photosensitive layer. For example, a composition containing a cinnamic acid ester structure.

A photosensitive layer in which a compound having an epoxy group and a diazonium salt are combined. For example, 2,5-diethoxy-4- (p-toluylthio) as a diazonium salt
Using benzenediazonium hexafluorophosphate, etc.

A photosensitive layer in which a cyclized rubber, a novolac resin and an azide compound are combined. For example, those using 4,4'-diazidobenzophenone or the like as the azide compound.

Diazo resin. For example, a condensation product of an aromatic diazonium salt and formaldehyde.

It is important that each of the above-mentioned photosensitive layers contains a reaction product of a triphenylmethane type basic dye and an aromatic sulfonate represented by the general formula (I).

[0032]

[Chemical 3] (In the formula, Ar represents a substituted or unsubstituted aromatic ring, and the substituent thereof is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, a mercapto group, a cyano group, a sulfonyl group, a carbon number of 1 to 20. Substituted or unsubstituted alkyl group, alkoxy group, amide group, acyloxy group, alkanoyl group, formyl group, carboxyl group, 2 to 2 carbon atoms
It is at least one selected from the group consisting of 20 substituted or unsubstituted alkenyl groups, alkenyloxy groups, substituted or unsubstituted aryl groups having 5 to 20 carbon atoms, and aryloxy groups, which may be the same or different. May be. M represents an alkali metal or ammonium salt. Here, examples of the triphenylmethane-based basic dye include, but are not limited to, the followings.

Basic B described in the color index
lue (basic bull) 1, 5, 7, 8, 11,
15, 26, Basic Violet (Basic
Violet) 1 (methyl violet), 2, 3 (crystal violet), 4, 23, Basic Gr
een (basic green) 1, 4 (malachite green), etc.

Specific examples of the aromatic sulfonate represented by the general formula (I) include potassium benzenesulfonate, sodium benzenesulfonate, ammonium benzenesulfonate and potassium 4-toluenesulfonate. Salt, 4-toluenesulfonic acid sodium salt, 4
-Toluenesulfonic acid ammonium salt, 4-hydroxybenzenesulfonic acid potassium salt, 4-hydroxybenzenesulfonic acid sodium salt, 4-hydroxybenzenesulfonic acid ammonium salt, 2-carboxybenzenesulfonic acid potassium salt, 2-carboxybenzenesulfonic acid sodium salt Salt, 2-carboxybenzenesulfonic acid ammonium salt, 3-carboxybenzenesulfonic acid potassium salt, 3-carboxybenzenesulfonic acid sodium salt, 3-carboxybenzenesulfonic acid ammonium salt, 3-nitrobenzenesulfonic acid potassium salt, 3-nitrobenzenesulfone Acid sodium salt, 3-nitrobenzenesulfonic acid ammonium salt, 4-chlorobenzenesulfonic acid potassium salt, 4-chlorobenzenesulfonic acid sodium salt, 2,4- Methylbenzenesulfonic acid potassium salt, 2,4-dimethylbenzenesulfonic acid sodium salt, 2,4-dimethylbenzenesulfonic acid ammonium salt, 2,4-dihydroxybenzenesulfonic acid potassium salt, 2,4-dihydroxybenzenesulfonic acid sodium salt 2,4-dihydroxybenzenesulfonic acid ammonium salt, 2,5-dihydroxy-1,4-benzenedisulfonic acid dipotassium salt, 2,5-dihydroxy-
1,4-benzenedisulfonic acid disodium salt, 2,5
-Potassium dicarboxybenzene sulfonate, 2,5
-Dicarboxybenzene sulfonic acid sodium salt, benzaldehyde-2-sulfonic acid sodium salt and the like, but are not limited thereto. Among these, those having a hydroxyl group, a carboxyl group or a methyl group as a substituent are particularly preferable.

Among these photosensitive layers, the photosensitive layer represented by is preferably a layer containing a reaction product of a triphenylmethane basic dye and an aromatic sulfonate represented by the general formula (I). .. The mixing ratio of each component of the photosensitive layer is not particularly limited, but it is preferable to use one or two or more of the above-mentioned radically polymerizable ethylenically unsaturated bond-containing monomer, prepolymer, and polymer.
0 to 500 parts by weight of an organic polymer compound is added,
0.5 to 50 parts of a photopolymerization initiator is added, 0.01 to 50 parts of a reaction product of a triphenylmethane-based basic dye and an aromatic sulfonate represented by the general formula (I) is added, and a film thickness 0.
Those obtained by making 1 to 100 μ are preferable.

In addition to the above components, it is possible to add additives such as pigments and polymerization inhibitors, if necessary.

The silicone rubber layer used in the present invention is obtained by crosslinking the linear polyorganosiloxane represented by the general formula (II).

[0038]

[Chemical 4] (In the formula, n is an integer of 2 or more, R1 and R2 are carbon atoms 1 to 2
0-substituted or unsubstituted alkyl group, having 2 to 20 carbon atoms
A substituted or unsubstituted alkenyl group having 5 to 20 carbon atoms
Of at least one substituted or unsubstituted aryl group, which may be the same or different, with a methyl group exceeding 60% being particularly preferred. )
As a general method for crosslinking a linear polyorganosiloxane, a method for crosslinking a linear polyorganosiloxane with a hydrolyzable functional group-containing silicon compound directly bonded to a silicon atom can be mentioned. In particular, the terminal has a silanol structure. With an organopolysiloxane having a molecular weight of 1,000 to 1,000,000 and two or more functional groups such as an alkoxy group, an acyloxy group, a ketoxime group, an amide group, an aminooxy group, an amino group, an alkenyloxy group and hydrogen directly bonded to a silicon atom. It is a commonly used method to cure into a rubber by reaction with a silicon compound contained therein. It is also possible to cure the organopolysiloxane with a radical initiator to give a rubber. In these curing, addition of a known catalyst is optional.

The mixing ratio of each component in the silicone rubber is not particularly limited, but is preferably the general formula (II).
0.1 to 100 parts by weight of a silicon compound containing a hydrolyzable functional group directly bonded to a silicon atom in 100 parts by weight of a linear polyorganosiloxane represented by
A composition obtained by adding a part by weight to obtain a film thickness of 0.5 to 100 μ, more preferably 0.5 to 10 μ is preferable.

A protective film is laminated on the surface of the silicone rubber layer for the purpose of protecting the silicone rubber layer forming the surface of the lithographic printing plate precursor which does not require dampening water and is constructed as described above. It is also possible to apply or transfer a thin plastic sheet to provide a protective layer.

[0041]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

Example 1 The following photosensitive layer was coated on an aluminum plate having a thickness of 0.3 mm,
It was heated and dried at 110 ° C. for 2 minutes to form a coating film having a thickness of 6 μm.

(A) N, N, N ′, N′-tetrakis (2-hydroxy-3-methacryloyloxypropyl) -m-xylylenediamine (4: 1 mol of glycidyl methacrylate and m-xylylenediamine) Specific reaction product) 100 parts by weight (b) "Pantex" T-5201 (polyurethane resin manufactured by Dainippon Ink and Chemicals, Inc.) 150 parts by weight (c) N-methylacridone 5 parts by weight (d) 4, 4'-bis (diethylamino) benzophenone 5 parts by weight (e) Reaction of crystal violet with sodium 4-toluenesulfonic acid product 0.5 parts by weight (f) dimethylformamide 800 parts by weight A silicone solution having the composition of 3 is applied, heated and dried at 80 ° C. for 3 minutes to give a silicone having a thickness of 3 μm.
I have a rubber layer.

(A) Polydimethylsiloxane having silanol groups at both ends (average molecular weight 35000) 100 parts by weight (b) Ethyltriacetoxysilane 12 parts by weight (c) Dibutyltin diacetate 0.2 parts by weight (d) 120 parts by weight of n-heptane Polyethylene terephthalate film "Lumira" (manufactured by Toray Industries, Inc.) having a thickness of 12 .mu.m is calendered on the surface of the thus obtained silicone rubber layer with a calendar roller.
And used as a lithographic printing plate precursor that does not require dampening water. A positive film was brought into vacuum contact with the printing plate precursor and exposed for 90 seconds from a distance of 1 m using a high pressure mercury lamp of 3 kW. Observation of the plate after exposure revealed that the dye in the non-image area (exposed area) had faded due to light irradiation, had a large contrast with the image area (unexposed area), and had good image printability. I understood it. The laminated film was removed from the exposed plate and developed by lightly rubbing with a pad impregnated with n-hexane to obtain a lithographic printing plate precursor without fountain solution with good image reproducibility. Was given.

When the original plate was stored at 30 ° C. for 6 months, the dye did not fade or aggregate.

Comparative Example 1 In Example 1, a fountain solution-free lithographic printing plate precursor was prepared by using crystal violet instead of the reaction product of crystal violet and sodium 4-toluenesulfonate. It was stored at 30 ° C. for 6 months in the same manner as in Example 1, but about 40% of fading occurred,
The image printability was deteriorated.

Example 2 In Example 1, the reaction product of Crystal Blue 26 and 4-toluenesulfonic acid sodium salt was replaced with the reaction product of Basic Blue 26 and 4-hydroxybenzenesulfonic acid sodium salt. A waterless lithographic printing plate was prepared. When exposed in the same manner as in Example 1, a good image printout property was exhibited. When the original plate was stored at 30 ° C. for 1 year, the fading rate of the dye was 5% or less and no aggregation occurred.

Example 3 In Example 1, the reaction product of Basic Green 1 and 2-carboxybenzenesulfonic acid sodium salt was used in place of the reaction product of crystal violet and 4-toluenesulfonic acid sodium salt. A waterless lithographic printing plate was prepared. When exposed in the same manner as in Example 1, a good image printout property was exhibited. I tried storing the original plate at 30 ℃ for 1 year, but the fading rate of the dye is 10%.
It was below and no aggregation occurred.

[0049]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, it has a good image print-out property and can be stably preserved for a long period of time without fading or agglomeration. Can be obtained.

Claims (1)

[Claims] 1. A lithographic printing plate precursor not requiring a fountain solution, which comprises a photosensitive layer and a silicone rubber layer provided in this order on a substrate, wherein the photosensitive layer comprises a triphenylmethane basic dye and the following general formula (I). A fountain solution-free lithographic printing plate precursor containing a reaction product with an aromatic sulfonate represented by [Chemical 1] (In the formula, Ar represents a substituted or unsubstituted aromatic ring, and the substituent thereof is a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, an amino group, a mercapto group, a cyano group, a sulfonyl group, or a carbon number of 1 to 20. Substituted or unsubstituted alkyl group, alkoxy group, amide group, acyloxy group, alkanoyl group, formyl group, carboxyl group, 2 to 2 carbon atoms
At least one selected from the group consisting of 20 substituted or unsubstituted alkenyl groups, alkenyloxy groups, substituted or unsubstituted aryl groups having 5 to 20 carbon atoms, and aryloxy groups, which may be the same or different. May be. M represents an alkali metal or ammonium salt. )