JPH0926665A - Photosensitive planographic printing plate requiring no dampening water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a planographic printing plate excellent in image reproducibility. SOLUTION: At least one kind of diamine represented by the formula is incorporated into a photopolymerizable photosensitive layer. In the formula, R1 is a divalent combining group, each of R2 -R5 is alkyl, aryl, aralkyl or a heterocyclic group, R2 and R3 or R4 and R5 may be combined to form a ring together with N, and R2 , and R4 or R3 and R5 may be combined to form a ring together with N-R1 -N.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dampening-free photosensitive lithographic printing plate which can be printed without dampening water.

[0002]

2. Description of the Related Art Various types of photosensitive lithographic printing plates requiring no fountain solution for performing lithographic printing without using fountain solution have been proposed. Among them, the one in which a photosensitive resin layer and a silicone rubber layer are sequentially coated on a substrate has extremely excellent performance, and is described in, for example, JP-B-54-26923 and JP-B-55-22781. You can list the things that are. The silicone rubber layer used in these photosensitive lithographic printing plates that do not require fountain solution is usually a polymer obtained by partially crosslinking a polymer having a polysiloxane as a main skeleton with a crosslinking agent. As the photosensitive resin layer, in the case of a positive type lithographic printing plate, a photopolymerization type photosensitive composition, a photoduplication type photosensitive composition or a diazo type photosensitive composition which is cured by exposure has been used. As an image forming method of a photosensitive lithographic printing plate having these layer configurations, generally, the photosensitive resin layer is cured by exposure, and in some cases, photoadhesion at the interface with the uppermost silicone rubber layer, The two layers are firmly bonded to each other to prevent the permeation by the developing solution and the elution of the photosensitive resin layer due to the permeation by the developing solution, thereby forming the non-image portion including the silicone rubber layer. On the other hand, in the image area, the developing solution is permeated through the silicone rubber layer to dissolve or swell a part or all of the uncured photosensitive resin layer, and then the silicone rubber layer thereon is removed by physical force. Formed.

In such an image forming method, JP-A-6-89023 proposes to add a water-soluble compound in the photosensitive layer to improve image reproducibility.
Further, Japanese Patent Laid-Open No. 2-226249 proposes to improve the image reproducibility by increasing the adhesive force with a silicone rubber layer by using a monomer containing an allyl group. Further, JP-A-2-236550 proposes to improve image reproducibility by using polyurethane having a glass transition temperature (Tg) of 20 ° C. or lower. However, in any case,
The condition was not satisfactory for practical use.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive lithographic printing plate which does not require fountain solution and has excellent image reproducibility.

[0005]

Such an object is achieved by the constitution (1) below. And a preferable structure is the following (2). (1) A photopolymerizable photosensitive layer and a silicone rubber layer are provided in this order on a substrate, and the photopolymerizable photosensitive layer contains at least one diamine represented by the following formula (I). Sex lithographic printing plate.

[0006]

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[In the formula (I), R ₁ represents a divalent linking group. R ₂ , R ₃ , R ₄ and R ₅ are each an alkyl group,
It represents an aryl group, an aralkyl group or a heterocyclic group, which may be the same or different. Also R ₂ and R
₃ or R ₄ and R ₅ may be linked together to form a ring with a nitrogen atom, and R ₂ and R ₄ or R ₃ and R ₅ are
Each may be linked to form a ring with the nitrogen atom and R ₁ . (2) at least one of said R ₂ in formula _{(I), R 3, R} 4 and R _{5 is, - (CH 2 CH 2 -O} ) p-
H or _{- (CH 2 CH (CH 3} -O) p-H [. Here, p is an integer of 1 or more] in which requiring no fountain photosensitive lithographic printing plate of the above (1).

[0008]

[Specific Configuration] Hereinafter, a specific configuration of the present invention will be described in detail.

The photosensitive lithographic printing plate not requiring fountain solution of the present invention (hereinafter also referred to as "waterless lithographic printing plate") has a photopolymerizable photosensitive layer and a silicone rubber layer laminated in this order on a substrate. The photopolymerizable photosensitive layer is a diamine represented by the formula (I) [shown in Chemical Formula 2 above. ] At least one is contained.

By containing such a diamine in the photopolymerizable photosensitive layer, it becomes easy to dissolve or swell a part or all of the photosensitive resin in the unexposed area,
Good image reproducibility.

The formula (I) will be described. In the formula (I), R ₁
Represents a divalent linking group. More specifically, R ₁ represents an alkylene group (including a cycloalkylene group) or an aralkylene group.

The alkylene group represented by R ₁ preferably has 2 to 12 carbon atoms, and may have a substituent. Specifically, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, cyclohexylene, or methylene or ethylene and cyclohexylene Examples thereof include a group in which a group is combined. These alkylene groups may further have a substituent, and examples of such a substituent include an alkyl group, an aryl group, an aralkyl group,
Examples thereof include an alkoxy group, a hydroxyl group, a cyano group, a carboxyl group, and a halogen atom. An alkyl group has a carbon number of 1 to 6, an aryl group is a phenyl group, an aralkyl group is a benzyl group, and an alkoxy group is an alkyl group. The part having 1 to 6 carbon atoms is preferable, and a chlorine atom can be mentioned as a specific example of the halogen atom.

The alkylene group may have an oxycarbonyl group, an oxy group, a thio group or the like and contains an ester bond, an ether bond, a thioether bond, or may have a repeating structure. When the repeating structure is included, the number of carbon atoms per repeating structure is 2 to 6
Is preferred. _{Specifically, -CH 2 CH 2 -O-CH} 2
_{CH 2 -, - CH 2 CH} (CH 3) -O-CH 2 CH
_{(CH 3) -, - CH} 2 CH 2 -C (O) -O-CH 2
_{CH 2 -O-C (O)} -CH 2 CH 2 -, - CH 2 CH 2
_{- (O-CH 2 CH 2} ) n -, - CH 2 CH (CH
_{3) - (O-CH 2} CH (CH 3)) n -, - CH 2 C
_{H 2 -C (O) -O- (} CH 2 CH 2 -O) n-C
(O) —CH ₂ CH ₂ — and the like, and examples thereof include structures containing a polyoxyethylene group and a polyoxypropylene group.
In this case, n = 2 to 30 is preferable.

The aralkylene group represented by R ₁ preferably has 7 to 12 carbon atoms, and specific examples thereof include a xylylene group. The aralkylene group may further have a substituent, and examples of the substituent include those similar to the alkylene group. Further, it may contain an ester bond, an ether bond, or a thioether bond.

In the formula (I), R _{2 to} R ₅ represent an alkyl group (including a cycloalkyl group), an aryl group, an aralkyl group or a heterocyclic group, which may be the same or different.

The alkyl group represented by R _{2 to} R ₅ preferably has 1 to 12 carbon atoms, and may be linear or branched, for example, a methyl group or an ethyl group. , Propyl group, butyl group, hexyl group, cyclohexyl group and the like. Further, the alkyl group may have a substituent, and as the substituent, an alkyl group,
Aryl group, alkoxy group, aryloxy group, hydroxy group, hydroxyalkyl group, hydroxyaryl group,
Examples thereof include a cyano group, an acyl group, a carboxyl group, a halogen atom, and the like, and the alkyl group represented by R _{2 to} R ₅ may further include an ester bond, an ether bond, or a thioether bond. Specific examples of the substituted alkyl group represented by R _{2 to} R ₅ include hydroxyethyl group, hydroxypropyl group, ethoxycarbonylmethyl group, ethoxycarbonylethyl group, cyanoethyl group, carboxymethyl group, carboxyethyl group, hydroxyethoxyethyl group. Group, methoxyethoxyethyl group, hydroxyethoxycarbonylethyl group, the number of repeating is 2 or more, preferably 2
Examples thereof include a polyoxyethylene group and a polyoxypropylene group having a terminal hydroxy group or an alkoxy group at 10 to 10.

The aryl group represented by R _{2 to} R ₅ preferably has 6 to 12 carbon atoms, and specific examples thereof include a phenyl group and a naphthyl group. These may have a substituent, and specific examples of the substituent include those similar to the alkyl group.

The aralkyl group represented by R _{2 to} R ₅ preferably has 7 to 12 carbon atoms, specifically, a benzyl group,
And a phenethyl group. These may have a substituent, and specific examples of the substituent include those similar to the alkyl group.

The heterocyclic group represented by R _{2 to} R ₅ includes
And a pyridyl group. These may have a substituent, and specific examples of the substituent include those similar to the alkyl group.

R ₂ and R ₃ or R ₄ and R ₅ may be connected to each other to form a ring together with the nitrogen atom (N). At this time, a group formed by R ₂ and R ₃ or R ₄ and R _{5, - (CH 2) 4 -} , - (CH 2) 5 -, - CH 2
_{CH 2 -O-CH 2 CH 2} -, - CH 2 C (O) -O-
C (O) CH ₂ — and the like, and examples of the nitrogen-containing ring formed include a morpholine ring, a morpholine-2,6-dione ring, a phenothiazine ring, and the like. R ₂ and R ₃ , R ₄ and R ₅
One of the combinations may have a ring structure, or the combination of both may have a ring structure.

R ₂ and R ₄ or R ₃ and R ₅ may be linked to form a ring together with the nitrogen atom (N) and R ₁ . At this time, the group formed by R ₂ and R ₄ or R ₃ and R ₅ is — (CH ₂ ) ₂ —, — (CH ₂ ) _{3
-, - (CH 2) 4} -, - (CH 2) 5 -, - (CH 2
_{CH 2 -O) q-CH 2} CH 2 - ( provided that, q is 1 to 4
Is an integer. ), And examples of the nitrogen-containing ring formed include a piperazine ring and a cryptand [2.2] ring. A combination of any one of R ₂ and R ₄ , a combination of R ₃ and R ₅ may have a ring structure, or a combination of both may have a ring structure. A combination of both may be a ring structure to form 1,4-diazabicyclo [2.2.2] octane or the like as a whole.

Preferred as R _{2 to} R ₅ are (C
_{H 2 CH 2 -O) p-} H, - (CH 2 CH (CH 3) -
O) p-H [where p is 1 or more, preferably 1 to 10]
Is an integer. ], And at least one of R _{2 to} R ₅ is preferably these groups.

In the present invention, it is preferable to use a compound having a hydrophilic group for the purpose of improving image reproducibility.

Specific examples of the diamine represented by the formula (I) are shown below, but the invention is not limited thereto.

[0025]

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[0026]

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[0027]

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[0028]

[Chemical 6]

Some diamines represented by the formula (I) are commercially available, and commercially available products can be used as they are. In addition to primary or secondary amines, halogenated alkyls, epoxy compounds, acrylic compounds are used. 3 in reaction with etc.
It can be graded and synthesized.

The diamine represented by the formula (I) may be used alone or in combination of two or more kinds. The amount thereof is 0.1 to the total solid content weight of the photopolymerizable photosensitive layer.
It is 20% by weight, preferably 1 to 10% by weight.

The photopolymerizable photosensitive layer (hereinafter also referred to as "photosensitive layer") in the present invention includes at least (1) at least one photopolymerizable ethylenic group in addition to the diamine represented by the formula (I). It contains a monomer having an unsaturated group, an oligomer or a macromonomer, (2) a polymer compound having film forming ability, and (3) a photopolymerization initiator.

Component (1): at least one photopolymerizable
Monomers, oligomers, etc.
The monomer other that can be used in the macromonomer present invention, the oligomer or macromonomer, for example, (A) alcohols (e.g., ethanol, propanol, hexanol, 2-ethylhexanol, cyclohexanol,
Acrylic acid or methacrylic acid ester of glycerin, hexanediol, trimethylolpropane, pentaerythritol, sorbitol, triethylene glycol, polyethylene glycol, polypropylene glycol, etc., and (B) amines (for example, ethylamine, butylamine, benzylamine, ethylenediamine, Reaction products of hexamethylenediamine, diethylenetriamine, xylylenediamine, ethanolamine, aniline and the like) with glycidyl acrylate, glycidyl methacrylate or allylglycidyl, (C) carboxylic acids (eg,
Reaction product of acetic acid, propionic acid, benzoic acid, acrylic acid, methacrylic acid, succinic acid, maleic acid, phthalic acid, tartaric acid, citric acid, etc.) with glycidyl acrylate, glycidyl methacrylate or allyl glycidyl, (D) amide Derivatives (eg, acrylamide, N-methylol acrylamide, t-butyl acrylamide, methylene bis acrylamide, diacetone acrylamide, etc.),
And the like.

Further, urethane acrylates as described in JP-B-48-41708, JP-B-50-6034, and JP-A-51-37193, JP-A-Sho-4.
Polyfunctional acrylates such as polyester acrylates described in 8-64183, JP-B-49-43191 and JP-B-52-30490, and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid, Methacrylate, N-methylol acrylamide derivatives described in U.S. Pat. No. 4,540,649 may be mentioned. Furthermore, Japan Adhesives Association Magazine Vol.2
0, No. 7, pages 300 to 308 (1984), etc., described as photocurable monomers and oligomers, P. Dreyfuss & RPQuirk, Encycl.Polym.Sci.
Eng., 7, 551 (1987), Chemical Industry, 38, 56.
(1987), Polymer Processing, 35, 262, (198
Macromonomers described in 6) and the like can also be used. However, it is not limited to these,
In the polyfunctional monomer, the unsaturated group may be a mixture of acrylic group, methacrylic group, allyl group, vinyl group and the like. These may be used alone or in combination. The amount used is 5 to 80% by weight, preferably 10 to 70% by weight, and more preferably 20 to 10% by weight, based on the total solid content of the photopolymerizable photosensitive layer.
60% by weight.

Component (2): High content having film forming ability
Child compound As the polymer compound having film-forming ability used in the present invention, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, epoxy resin, (meth) acrylate copolymer Polymers, (meth) acrylamide-based copolymers, polyurethane resins, vinyl acetate-based copolymers, polystyrene, phenoxy resins, polyvinyl chloride, cellulose acetate derivatives, alcohol-soluble polyamides, (meth) acrylic acid copolymers, maleic acid Examples thereof include a copolymer, polyvinyl alcohol, water-soluble polyamide, water-soluble polyurethane, water-soluble cellulose, polyvinylpyrrolidone and the like.

Further, as the polymer compound capable of forming a film, a polymer compound having a photopolymerizable or photocrosslinkable olefinic unsaturated double bond group in its side chain can be used. Further, as the polymer compound capable of forming a film, a polymer compound having a carboxyl group or a carboxyl group-containing group in its side chain can be used. Polyurethane resins are preferred, but not limited to. Further, various compounds may be mixed and used. The amount used is 20 to 90% by weight, preferably 30 to 8% by weight based on the total solid content of the photopolymerizable photosensitive layer.
0% by weight.

Component (3): Photopolymerization Initiator The following are typical examples of the photopolymerization initiator used in the present invention.

A) Benzophenone derivatives such as benzophenone, Michler's ketone, xanthone, anthrone, thioxanthone, acridone, 2-chloroacridone, 2-chloro-Nn-butylacridone, 2,4-
Diethylthioxanthone, fluorenone, etc. b) benzoin derivative, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, etc. c) quinones, for example, p-benzoquinone, β-naphthoquinone, β-methylanthraquinone, etc. d) sulfur compound, For example, dibenzyl disulfide, di-n-butyl disulfide, etc. e) Azo or diazo compound, for example, 2-azobisisobutyronitrile, 1-azo-bis-1-cyclohexanecarbonitrile, p-diazobenzyl Ethylaniline, Congo red, etc. f) Halogen compounds such as carbon tetrabromide, silver bromide, α
-Chloromethylnaphthalene, trihalomethyl-s-triazine compounds, etc. g) Peroxides such as benzoyl peroxide.

These may be used alone or in combination of two or more. The amount of these photopolymerization initiators added is 0.1 to 25% by weight, preferably 3 to 20% by weight, based on the total photosensitive layer composition.

In addition to the above components, it is preferable to add a thermal polymerization inhibitor, for example, hydroquinone, p-methoxyphenol,
Di-t-butyl-p-cresol, pyrogallol, t-
Butylcatechol, 4,4'-thiobis (3-methyl-
6-t-butylphenol), 2,2′-methylenebis (4-methyl-6-t-butylphenol), 2-mercaptobenzimidazole, etc. are useful, and in some cases, dyes or pigments and pigments for the purpose of coloring the photosensitive layer and A pH indicator or a leuco dye may be added as a printing agent. Depending on the purpose, a small amount of polydimethylsiloxane, methylstyrene-modified polydimethylsiloxane, olefin-modified polydimethylsiloxane,
Silicone compounds such as polyether-modified polydimethylsiloxane, silane coupling agent, silicone diacrylate, silicone dimethacrylate may be added.
A silicone-based surfactant or a fluorine-based surfactant may be added to improve coating properties. Further, a diazo resin may be added to improve the adhesiveness between the photosensitive layer and the primer layer. In addition, plasticizers (for example, polyethylene glycol, tricresyl phosphate, etc.), stabilizers (for example, phosphoric acid, etc.) and Japanese Patent Application No. 6-121359 for imparting flexibility to the coating film. The sulfone sun described in No. 1 may be added. The amount of these additives is usually 10% by weight or less based on the total photosensitive layer composition.
In some cases, the hydrophobic silica powder treated with the (meth) acryloyl group- or allyl group-containing silane coupling agent may be added in an amount of 50% by weight or less based on the total photosensitive layer composition.

The composition of the photopolymerizable photosensitive layer as described above is
For example, 2-methoxyethanol, 2-methoxyethyl acetate, methyl lactate, ethyl lactate, propylene glycol monomethyl ether, methanol, ethanol,
It is provided on the substrate by dissolving in a suitable solvent such as methyl ethyl ketone, water or the like or a mixed solvent in which these are appropriately combined. The coating amount is about 0.1 by dry weight.
A range of 10 g / m ² is suitable, preferably 0.5-6 g /
a m ^2.

In the present invention, the crosslinked silicone rubber layer provided and used on the photopolymerizable photosensitive layer is a partially or entirely crosslinked polydiorganosiloxane and has the following repeating units.

[0042]

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Here, R represents an alkyl group, an aryl group, an alkenyl group or a monovalent group in which these are combined, and R may be the same or different, and these groups are halogen atoms or amino groups. It may have a functional group such as a group, a hydroxy group, an alkoxy group, an aryloxy group, a (meth) acryloxy group, and a thiol group.

If necessary, fine particles of an inorganic material such as silica, calcium carbonate or titanium oxide, the above-mentioned silane coupling agent, titanate coupling agent or aluminum coupling agent may be adhered to the silicone rubber layer. An auxiliary agent or a photopolymerization initiator may be added.

Polysiloxane having a molecular weight of several thousand to several hundred thousand and having a functional group at the terminal is used as a raw material of a polymer (silicone rubber) having the above polysiloxane as a main skeleton. The method is cross-linked and cured to form a silicone rubber layer. That is, specifically, the silane-based cross-linking agent represented by the following formula (II) is mixed with the above-mentioned polysiloxane having hydroxyl groups at both ends or one end, and an organometallic compound such as an organic compound is added as necessary. It is formed by adding a catalyst such as a tin compound, an inorganic acid, or an amine, and heating the polysiloxane and the silane-based crosslinking agent, or by condensation-curing at room temperature.

R _t SiX _4-t (II)

Here, t is an integer of 1 to 3, R is a substituent similar to R shown above, and X is -OH, -OR ² ,-.
OAc, -O-N = C ( R 2) (R 3), - Cl, -B
It represents a substituent such as r or -I. Where R ² , R ³
Has the same meaning as R described above, and R ² and R ³ may be the same or different. In addition, Ac represents an acetyl group.

The silicone rubber layer may also be formed by condensation-curing an organopolysiloxane having a hydroxyl group at the terminal, a hydrogenpolysiloxane crosslinking agent and, if necessary, the above-mentioned silane crosslinking agent.

Further, an addition type silicone rubber layer which is crosslinked by an addition reaction between an ≡SiH group and a —CH═CH— group is also useful. The addition type silicone rubber layer has an advantage that it is relatively insensitive to humidity at the time of curing, can be crosslinked at a high speed, and can easily obtain certain physical properties. In the case of a condensation type silicone rubber layer, if a carboxylic acid is present in the photopolymerizable photosensitive layer, curing failure may occur depending on the cross-linking agent used, whereas in the addition type, the presence of the carboxylic acid is sufficient. To cure. Thus, in the additive type,
Since the carboxylic acid can be present in the photopolymerizable photosensitive layer and can be further developed with a developer mainly containing water or alkaline water, the photosensitive printing plate can be easily designed. The addition-type silicone rubber layer used here is obtained by reacting a polyvalent hydrogenorganopolysiloxane with a polysiloxane compound having two or more —CH═CH— bonds in one molecule. Component: 1) 100 parts by weight of organopolysiloxane having at least two alkenyl groups (preferably vinyl groups) directly bonded to silicon atoms in one molecule 2) Organohydro having at least two ≡SiH bonds in one molecule Gen polysiloxane 0.1 to 1000 parts by weight 3) Addition catalyst 0.00001 to 10 parts by weight, which is cured and crosslinked. The alkenyl group of the component 1) may be at the terminal or in the middle of the molecular chain, and the organic group other than the alkenyl group is a substituted or unsubstituted alkyl group or aryl group. The component 1) may contain a small amount of hydroxyl groups. Component 2) reacts with component 1) to form a silicone rubber layer, but plays a role of imparting adhesiveness to the photopolymerizable photosensitive layer. The hydrogen group of component 2) may be at the terminal or in the middle of the molecular chain, and the organic groups other than hydrogen are selected from the same as those of component 1). From the viewpoint of improving the ink resilience, it is preferable that the organic groups of the components 1) and 2) have a methyl group in 60% or more of the total number. The molecular structure of component 1) and component 2) may be linear, cyclic, or branched, and it is preferable that at least one of them has a molecular weight of more than 1,000 from the viewpoint of rubber physical properties. It is preferable that the molecular weight exceeds 1,000.

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

The addition catalyst of the component 3) is arbitrarily selected from known ones, but a platinum-based compound is particularly preferable, and platinum simple substance, platinum chloride, chloroplatinic acid, olefin-arranged platinum and the like are exemplified. In order to control the curing rate of these compositions, organopolysiloxanes containing vinyl groups such as tetracyclo (methylvinyl) siloxane, alcohols containing carbon-carbon triple bonds, acetone, methyl ethyl ketone, methanol, ethanol, propylene glycol monomethyl ether It is also possible to add a crosslinking inhibitor such as.

These compositions are characterized in that an addition reaction occurs at the time when the three components are mixed and curing begins, but the curing rate rapidly increases as the reaction temperature increases. Therefore, for the purpose of prolonging the pot life of the composition until rubberization and shortening the curing time on the layer, the curing conditions of the composition are a temperature within a range in which the characteristics of the substrate and the photopolymerizable photosensitive layer do not change. It is preferable to keep the temperature under the conditions and until it is completely cured from the viewpoint of the stability of the adhesive force with the photopolymerizable photosensitive layer.

In addition to these compositions, alkenyltrialkoxysilane and the following siloxane compounds

[0054]

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[0055]

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Addition of a known adhesion-imparting agent such as, for example, a hydroxyl group-containing organopolysiloxane which is a composition of a condensation type silicone rubber layer, a silicone oil composed of dimethylpolysiloxane having a trimethylsilyl group at the terminal, and a trimethylsilyl group at the terminal It is also possible to add dimethylpolysiloxane, which is a silicone oil composed of phenylmethylpolysiloxane copolymer, and silane (or siloxane) containing a hydrolyzable functional group. Further, a known filler such as silica may be added to improve the rubber strength.

The silicone rubber layer in the present invention serves as a printing ink repellent layer. When the thickness is small, there are problems such as a decrease in ink repelling property and easy scratching. From the viewpoint of deterioration, it is suitable that the coating amount after drying is 0.5 to 5 g / m ² , and preferably 1
~ 3 g / m ² .

The waterless lithographic printing plate of the present invention must have flexibility so that it can be set in an ordinary printing machine and at the same time withstand the load applied during printing. Therefore,
As a typical substrate, a coated paper, a metal plate such as aluminum, a plastic film such as polyethylene terephthalate, rubber, or a combination thereof can be given. Various surface treatments described in Japanese Patent Application No. 6-935 may be applied for the purpose of whitening the surface of these substrates, erasing rolled eyes, and preventing halation. The surface of these substrates can be further coated with a primer layer or the like for the purpose of preventing halation and other purposes.

Further, as disclosed in JP-A-4-3166, in order to improve the adhesion between the substrate and the photosensitive layer or the primer layer, the surface of the substrate is surface-treated with a silane coupling agent. You can also

As the primer layer, various kinds can be used for improving the adhesion between the substrate and the photosensitive layer, preventing halation, dyeing an image and improving printing characteristics. For example, various photosensitive polymers as disclosed in JP-A-60-22903, which are exposed and cured before laminating a photosensitive layer, are disclosed in JP-A-62-50760. Which is obtained by heat-curing an epoxy resin, which is hardened by gelatin disclosed in JP-A-63-133151, and urethane resin and silane coupling which are disclosed in JP-A-3-200965. Examples thereof include those using an agent and those using a urethane resin disclosed in JP-A-3-273248. In addition, those obtained by hardening gelatin or casein are also effective. Further, for the purpose of softening the primer layer, polyurethane, polyamide, styrene / butadiene rubber, carboxy-modified styrene / butadiene rubber, acrylonitrile / butadiene rubber, carboxy-modified acrylonitrile having a glass transition temperature of room temperature or lower is contained in the primer layer. Polymers such as / butadiene rubber, polyisoprene, acrylate rubber, polyethylene, chlorinated polyethylene and chlorinated polypropylene may be added. The addition ratio is arbitrary, and the primer layer may be formed with only the additives as long as the film layer can be formed.

Further, in these primer layers, dyes, pH indicators, printout agents, photopolymerization initiators, adhesion aids (for example, polymerizable monomers, diazo resins, silane coupling agents, Additives such as titanate coupling agents and aluminum coupling agents), pigments and silica powder can also be included. Generally, the coating amount of the primer layer is suitably in the range of 0.1 to 20 g / m ^{2 on} a dry weight basis, and preferably 1 to 10 g / m ² .

In the photosensitive lithographic printing plate not requiring fountain solution described above, various silicone rubber layers may be further coated on the silicone rubber layer. Further, for the purpose of increasing the adhesive strength between the photopolymerizable photosensitive layer and the silicone rubber layer or preventing poisoning of the catalyst in the silicone rubber composition, the distance between the photopolymerizable photosensitive layer and the silicone rubber layer is reduced. May be provided with an adhesive layer.

Further, in order to protect the surface of the silicone rubber layer which becomes the ink repellent layer, a transparent film such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate, cellophane, etc. is formed on the ink repellent layer. May be laminated or coated with a polymer. These films may be used after being stretched. Further, this film may be subjected to a matting treatment in order to improve the vacuum adhesion in the baking frame during image exposure.

The waterless lithographic printing plate of the present invention is exposed through a transparent original image and then developed with a developer capable of dissolving or swelling a part of the photosensitive layer in the image area (unexposed area).

As the developer used in the present invention, those known as a developer for a waterless planographic printing plate can be used, but water or an aqueous solution of a water-soluble organic solvent containing water as a main component is preferable. Considering safety and flammability, the concentration of the water-soluble solvent is preferably less than 40% by weight, and development with only water is particularly desirable. Known compounds include, for example, aliphatic hydrocarbons (hexane, heptane, “Isopar E, G, H” (manufactured by Esso Chemical Co., Ltd.), gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene). Etc.) or halogenated hydrocarbons (trichlene, etc.) to which the following polar solvent is added, or the polar solvent itself. Such polar solvents include alcohols (methanol, ethanol, propanol, isopropanol, benzyl alcohol, ethylene glycol monomethyl ether, 2-ethoxyethanol, diethylene glycol monoethyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether. Ethyl ether,
Dipropylene glycol monomethyl ether, polyethylene glycol monomethyl ether, polypropylene glycol, tetraethylene glycol, etc.), ketones (acetone, methyl ethyl ketone, etc.), esters (ethyl acetate, methyl lactate, butyl lactate, propylene glycol monomethyl ether acetate, diethylene glycol acetate, Diethyl phthalate etc.), and others, triethyl phosphate, tricresyl phosphate, etc.

Further, water is added to the organic solvent-based developer, or the organic solvent is solubilized in water by using a surface active agent or the like, or an alkaline agent (for example, sodium carbonate or diethanolamine). , Sodium hydroxide, etc.)
And water (tap water, pure water, distilled water, etc.) and the like.

Further, dyes such as crystal violet, Victoria pure blue, and Astrazone red can be added to the developing solution to dye the image area simultaneously with the development.

The development can be carried out by a known method such as rubbing the plate surface with a developing pad containing the above-mentioned developing solution, or pouring the developing solution onto the plate surface and then rubbing it with a developing brush in water. . The developer can be developed at any temperature, but is preferably from 10C to 50C. As a result, the ink repellent layer in the developing portion is removed, and that portion becomes the ink receiving portion.

In the printing plate thus obtained, the exposed image portion can be dyed with a dyeing solution so as to be detected in order to confirm the image forming property. When the developer does not contain a dye for dyeing the exposed image portion, it is treated with the dye after development. By impregnating the dyeing solution with a soft pad and lightly rubbing the image portion, only the exposed image portion of the photosensitive layer is dyed, whereby it can be confirmed that the development is sufficiently performed up to the highlight portion. As the dyeing solution, one or more selected from water-soluble disperse dyes, acid dyes and basic dyes may be used alone or as a mixture of two or more of water, alcohols, ketones and ethers. What is dissolved or dispersed is used. In order to improve the dyeability, carboxylic acids, amines, surfactants,
It is also effective to add a dyeing aid, an antifoaming agent and the like.

The printing plate dyed with the dyeing solution is preferably washed with water and then dried, whereby the stickiness of the plate surface can be suppressed and the handling property of the printing plate can be improved.

When the printing plates thus processed are stacked and stored, it is preferable to insert and sandwich a slip sheet for protecting the printing plates.

It is preferable that the above-mentioned development and dyeing treatments, or subsequent washing and drying treatments are carried out by an automatic processor. A preferable example of such an automatic processor is described in JP-A-2-22661.

[0073]

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

Examples 1 to 11 and Comparative Example 1 Waterless planographic printing plates were prepared as follows.

[Primer layer] A 0.3 mm thick JIS A 1050 aluminum plate degreased by a conventional method was immersed in a 1% by weight aqueous solution of KBM603 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is an aminosilane coupling agent. It was dried at room temperature. The following primer layer was applied on the aluminum plate so that the dry weight was 4 g / m ^2, and the coating was dried by heating at 140 ° C. for 2 minutes.

Samprene IB1700D (manufactured by Sanyo Kasei Co., Ltd.) 10 parts by weight Hexafluorophosphate of condensation product of p-diazodiphenylamine and paraformaldehyde 0.1 parts by weight TiO ₂ 0.1 parts by weight Di Fencer MCF323 (manufactured by Dainippon Ink and Chemicals, Inc.) 0.03 parts by weight-Propylene glycol methyl ether acetate 50 parts by weight-Methyl lactate 20 parts by weight Pure water 1 part by weight

After that, Nuark FT261V UDNS ULTRA
-PLUS FLIPTOP PLATE MAKER Using a vacuum exposure machine, 20
Count exposure.

[Photosensitive layer] A photopolymerizable photosensitive solution having the following composition was dried on an aluminum plate coated with the above primer layer to a dry weight of 3
It was applied so as to be g / m ² and dried at 100 ° C. for 1 minute.

Polyurethane resin (isophorone diisocyanate / polyester (adipic acid / 1,4-butanediol / 2,2-dimethylpropane-1,3-diol / isophoronediamine) 1.5 parts by weight of formula (I) Diamine (Table 1) 0.2 parts by weight A-600 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 0.5 parts by weight Xylylenediamine 1 mol / glycidyl methacrylate 4 mol adduct 1.3 parts by weight Ethylmihi Razketone 0.35 parts by weight 2-Chlorothioxanthone 0.10 parts by weight Victoria Pure Blue BOH naphthalene sulfonic acid hydrochloric acid 0.01 parts by weight Defensor MCF323 (Dainippon Ink and Chemicals, Inc.) 0.03 parts by weight Parts-Methyl ethyl ketone 10 parts by weight-Propylene glycol methyl ether 25 parts by weight

[Silicone Rubber Layer] The following silicone rubber composition liquid was applied on the above photopolymerizable photosensitive layer so that the dry weight was 2 g / m ² , and dried at 140 ° C. for 2 minutes.

9 parts by weight of α, ω-divinylpolydimethylsiloxane (polymerization degree: about 700) 0.5 part by weight of polydimethylsiloxane (polymerization degree: about 8,000) ・ Olefin-chloroplatinic acid 0.2 part by weight ・inhibitor _{(CH≡C-C (CH 3)} 2 -O-Si (CH 3) 3) 0.3 parts by weight Isopar G (manufactured by Esso chemical Co.) 140 parts by weight the following siloxane compound (Formula 10) 0.5 parts by weight

[0082]

Embedded image

On the surface of the silicone rubber layer obtained as described above, a 6 μm-thick single-side matted polyethylene terephthalate film was laminated so that the non-matted surface was in contact with the silicone rubber layer, and the waterless planographic printing plate of the present invention was laminated. Printing plates (Examples 1 to 11) were obtained.

A waterless planographic printing plate (Comparative Example 1) containing no diamine represented by the formula (I) was obtained.

Furthermore, in the waterless planographic printing plate of Example 1, instead of diamine, the compound (a) described in JP-A-6-89023 and the compound (B) described in JP-A-2-226249 were used. Waterless planographic printing plates (Comparative Examples 2 and 3) were obtained. Compound (a),
(B) is specifically shown in the footnote of Table 1. The compound described in JP-A-2-236550 is the same as the polyurethane resin in the photosensitive layer.

A positive film having a halftone dot image of 300 lines / inch is overlaid on these printing plates, and FT261V manufactured by Nuark Co., Ltd.
UDNS ULTRA-PLUS FLIPTOP PLATE MAKER Using a vacuum exposure machine, after exposing for 30 counts, the laminate film was peeled off.

While the plate was immersed in water at 40 ° C., it was rubbed with a development pad to remove the unexposed silicone rubber layer, and then dyed with a dyeing solution having the following composition to obtain a waterless planographic printing plate precursor.

(Staining solution) -Crystal violet 0.1 part by weight-Diethylene glycol monoethyl ether 15 parts by weight-Pure water 85 parts by weight

Using these plates, a Heidelberg GTO printing machine without a dampening water supply device was used
TOYO KING ULTRA TUK Printed with Aqualess G black ink, the reproducibility of halftone dots in highlight and shadow areas, which was reproducible, was evaluated in%. The results are shown in Table 1.

[0090]

[Table 1]

As is clear from the above results, the waterless planographic printing plate of the present invention has excellent image reproducibility.

Example 12 The following photosensitive layer was coated on the exposed aluminum substrate for coating the primer layer used in Example 1 so that the dry weight was 2 g / m ^2, and dried at 120 ° C. for 1 minute.

Polyurethane resin 1.5 parts by weight Diphenylmethane 4,4-diisocyanate Hexamethylene diisocyanate Tetraethylene glycol dimethylolpropanoic acid Sartomer 9035 (manufactured by Somal) 1.0 parts by weight Xylylenediamine 1 mol / glycidyl methacrylate 4 mol Additive 0.5 part by weight-Ethyl Michler's ketone 0.3 part by weight- 2,4-diethylthioxanthone 0.1 part by weight-N-n-butylacridone 0.1 part by weight-Victoria Pure Blue BOH naphthalene sulfone Acid salt 0.01 parts by weight-Defencer MCF323 (manufactured by Dainippon Ink and Chemicals, Inc.) 0.03 parts by weight-Compound 5 0.2 parts by weight-Methyl ethyl ketone 10 parts by weight-Propylene glycol methyl ether 25 parts by weight

A silicone rubber layer and a cover film were provided on the photopolymerizable photosensitive layer in the same manner as in Example 1 to obtain a waterless planographic printing plate.

After image exposure, development and printing in the same manner as in Example 1, the dot reproducibility was evaluated. As a result, the highlight image was 1% and the shadow was 99%, showing good image reproducibility.

Comparative Example 4 A waterless lithographic printing plate was obtained in the same manner as in the waterless lithographic printing plate of Example 12 except that Compound 5 was not added. When the halftone dot reproducibility of this waterless lithographic printing plate was evaluated in the same manner as in Example 1, highlight 10 was obtained.
% And shadow 90%, the image reproducibility was deteriorated.

[0097]

The waterless planographic printing plate of the present invention has remarkably excellent image reproducibility.

Claims (1)

[Claims] 1. A fountain solution having a photopolymerizable photosensitive layer and a silicone rubber layer in this order on a substrate, wherein the photopolymerizable photosensitive layer contains at least one diamine represented by the following formula (I). No need photosensitive lithographic printing plate. Embedded image [In the formula (I), R ₁ represents a divalent linking group. R ₂ , R
₃ , R ₄ and R ₅ are each an alkyl group, an aryl group,
It represents an aralkyl group or a heterocyclic group, which may be the same or different. Also R ₂ and R ₃ or R ₄
And R ₅ may each be linked to form a ring with the nitrogen atom, and R ₂ and R ₄ or R ₃ and R ₅ may be linked to each other to form a ring with the nitrogen atom and R _1. . ]