JPS61275759A - Developing solution for photosensitive lithographic printing plate without requiring damping water - Google Patents

Abstract

PURPOSE:To eliminate the scratching of a silicone rubber layer in a non-image part and to decrease the danger of firing by constituting a developing soln. of a prescribed org. solvent, activator and >=30wt% water. CONSTITUTION:The developing soln. constituted of the org. solvent for dissolving or swelling a photosetting type photosensitive layer, the org. solvent for swelling silicone rubber, activator and >=30wt% water is used for the developing soln. of the photosensitive lithographic printing plate without requiring damping water formed by laminating the photosensitive layer and silicone rubber layer on a substrate. Such developing soln. contains the prescribed ratio of water and therefore said soln. obviates the scratching of the silicone rubber layer in the non-image part during development. Since the soln. contains the water, the soln. has a high flash point and contributes to a decrease in the danger of ignition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a developer for a silicone rubber upper layer type photosensitive lithographic printing plate that does not require dampening water and has a silicone rubber layer as an ink repellent layer, and particularly relates to a developer for a photosensitive lithographic printing plate that does not require dampening water and has a silicone rubber layer as an ink repellent layer. % or more of water.

[Conventional technology]

Various types of photosensitive lithographic printing plates that do not require dampening water have already been proposed using a silicone rubber layer as an ink repellent layer. Among them, Special Publication No. 54-26923, Special Publication No. 55-2
No. 2781 and Japanese Patent Publication No. 56-23150, photosensitive lithographic printing plates that do not require dampening water are those in which a photocurable photosensitive layer and a silicone rubber layer are sequentially laminated on a substrate. It is possible to print tens of thousands of sheets without using dampening water using a printing plate made with this technology.

The above-mentioned photosensitive lithographic printing plate that does not require dampening water is usually plate-made through the following exposure and development steps.

First, the dampening water-less photosensitive lithographic printing plate is exposed to actinic light through a vacuum-sealed original film. After exposure, the printing original plate is immersed in a developer containing paraffin hydrocarbon or paraffin hydrocarbon as its main component. As a result, the silicone rubber layer in the unexposed areas is violently swollen by the developer and removed with the elution of only the silicone rubber layer in the unexposed areas or the photosensitive layer in the unexposed areas. The portion from which the silicone rubber layer is removed becomes the image area. On the other hand, although the silicone rubber layer in the exposed area is slightly swollen by the developer, it is strongly adhered to the photocured photosensitive layer, so it remains on the plate surface without being soaked even when rubbed strongly with a developing pad, and this area is exposed to ink. By forming the repellent non-image area, a lithographic printing plate that does not require dampening water can be made.

In general, the essential components of a developer for a photosensitive lithographic printing plate that does not require dampening water and uses a silicone rubber layer as an ink-repellent layer include a component that swells the silicone rubber layer (hereinafter referred to as a "silicone rubber swelling agent") and a component under the silicone rubber layer. A component that swells or dissolves the photosensitive layer (hereinafter referred to as "development accelerator") can be considered. Silicone rubber swelling agents include paraffinic hydrocarbons, such as pentane, hexane, heptane,
Single solvents such as octane, nonane, decane, mixtures of isomers, etc., or petroleum fractionation products corresponding to mixtures thereof, such as Isopar G, Isopar H
(manufactured by Exxon Chemical Co., Ltd.) and the like are used as useful solvents. In addition, alcohols, esters, ketones, ethers, aromatic hydrocarbons, halogenated hydrocarbons, carboxylic acids, and the like are effective as development accelerators.

[Problems to be Solved by the Invention] By the way, in the conventional silicone rubber-layered developer for photosensitive lithographic printing plates that does not require dampening water, the developer is based on a silicone rubber swelling agent and contains a development accelerator. As a result, a silicone rubber swelling agent on the tooth edges necessary to swell the silicone rubber layer is used, and scratches are likely to occur in the silicone rubber layer in non-image areas during development. In addition, this silicone rubber swelling agent is a paraffinic hydrocarbon and is extremely dangerous if it ignites for some reason, and when automatic processing is sometimes carried out, it is necessary to use an automatic processing machine that is carefully considered for explosion protection.

Such automatic processors can produce photosensitive lithographic printing plates (conventional PS) that can be processed with conventional water-based developers.
Compared to automatic developing machines for printing plates, it is very expensive and economically disadvantageous.

[Means for solving problems]

The present inventors have focused on this point, and have made extensive studies to uniformly mix the minimum required amount of silicone rubber swelling agent and development accelerator with water, either alone or by adding a surfactant or a third polar substance. The present inventors have discovered that the above-mentioned problems can be solved by a silicone rubber-layered developer for photosensitive lithographic printing plates that does not require dampening water and contains 30 weight percent or more of water, and has completed the present invention. That is, the present invention relates to a developer for a photosensitive lithographic printing plate that does not require dampening water and is formed by laminating a photocurable photosensitive layer and a silicone rubber layer in this order on a substrate, and the developer dissolves or swells the photosensitive layer. It is characterized by comprising an organic solvent, an organic solvent for swelling the silicone rubber layer, an activator, and 30% by weight or more of water.

The contents of the present invention will be explained in detail below.

Photosensitive layer> The photosensitive layer used in the present invention may be any layer as long as its solubility in a developer decreases before and after exposure.

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

(1) An unsaturated monomer or oligomer thereof with a boiling point of 100°C or higher and nonvolatile at room temperature, a photosensitizer, a thermal polymerization inhibitor, and if necessary, a filler to provide shape retention at room temperature and some A composition containing an additive.

Examples of unsaturated monomers include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxyethyl(meth)acrylate,
A series of acrylic esters such as hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, 1-chloro-2-hydroxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, methacrylic ester order, ethylene bisacrylamide , acrylamide derivatives such as N-methylol acrylamide and methoxymethyl acrylamide, esters of allyl alcohol such as triallyl cyanurate, triallyl phosphate, diallyl phthalate and diallyl maleate, other styrene derivatives, cinnamic acid derivatives, etc. I can do it.

Examples of photosensitizers include benzophenone derivatives, benzoin derivatives, anthraquinone derivatives, aldehydes, ketones,
Sulfur compounds, halogen compounds, or dyes such as methylene blue and riboflavin can be used.

As the thermal polymerization inhibitor, hydroquinone derivatives, phenol derivatives, nitro-substituted benzenes, tertiary amines, and phenothiazine derivatives are used.

Fillers or additives include colloidal silica, calcium carbonate, magnesium carbonate, fine powder of inorganic substances such as iron oxide, polyvinyl acetate, poly(meth)acrylate, polyethylene, polypropylene, and polyvinyl chloride with a molecular weight of several thousand. Examples include vinyl polymers such as polyvinylidene chloride, resol phenol resins before curing, urea resins, melamine resins, epoxy resins, and unsaturated polyester resins.

(2) R1 and R2 represent an alkyl group having 1 to 10 carbon atoms in the main chain or side chain of the polymer)
A composition consisting of a polymer compound containing.

Polymers containing photosensitive groups as main components or side chains of photosensitive polymers such as polymers, polyamides, and polycarbonate necks (for example, U.S. Pat. No. 3,030,208, U.S. Pat. No. 707.373 and No. 3, 453.23
Compounds such as those described in the specifications of No. 7); those whose main components are photosensitive polyesters derived from (2-propylidene) malonic acid compounds such as Cinnami IJ denmalonic acid and difunctional glycols. (e.g., photopolymers such as those described in U.S. Pat. No. 2,956,878 and U.S. Pat. No. 3,173,787); cinnamate esters of hydroxyl group-containing polymers (e.g., U.S. Pat. No. 2.690.966, U.S. Pat. No. 2.752)
．． 372, No. 2, 732.301, etc.), as well as JP-A-58
The polymers described in Japanese Patent No. 25302 and No. 59-17550 are included.

(3) Photosensitive diazo resin or azide resin and if necessary a photosensitizer and some filler additives.

Examples of the photosensitive diazo resin include zinc chloride double salts of condensates of formaldehyde and diazo amines such as paradiazodiphenylamine, paradiazomonoethylaniline, and paradiazobenzylethylaniline.

Examples of the photosensitive azide resin include azidophthalate ester or azide benzoate of polyvinyl alcohol, styrene-maleic anhydride copolymer, and aromatic azido alcohol such as β-(4-azidophenol).
Examples include esters of ethanol.

As the photosensitizer, filler, and additives, those listed in the example (1) can be used.

Among these, particularly preferred is the photodimerization type (2).

The thickness of the photosensitive layer as explained above is preferably as thin as possible as long as the photosensitive layer and silicone rubber layer in the image area can be removed in the development process after image exposure, but as a general guideline: 1 μ or less, especially 0.1 to 0
．． It is desirable and preferable that the thickness be selected from the range of 5μ.

Silicone Rubber Layer> The silicone rubber layer used in the present invention is mainly composed of a linear organic polysiloxane having a molecular weight of several thousand to several hundred thousand and having the following repeating units.

Here, R3 is an alkyl group having 1 to 10 carbon atoms or a phenyl group, but preferably 60% or more of R3 is a methyl group. Such linear organopolysiloxane is
It is common to add a reactive crosslinking agent to form a crosslinked silicone rubber. Crosslinking agents used in so-called room temperature (low temperature) curing silicone rubbers include acetoxysilanes, ketoximesilanes, minosilanes, amidosilanes, alkoxysilanes, and hydroxysilanes with or without monovalent organic groups bonded to silicon atoms. Silane such as
There are siloxanes, organo-hydrodiene polysiloxanes, etc. which are condensates of these with a low degree of polymerization. In addition, in order to improve the adhesive strength of the photosensitive layer/silicone rubber layer and prevent the interlayer adhesive strength from decreasing even after a long period of time, reactive silane compounds having an allyl isocyanurate group, reactive silane compounds having an aminoalkyl group, etc. are used. It may also be added to silicone rubber compositions.

The amount of the reactive crosslinking agent and/or reactive silane compound contained in the silicone rubber layer is preferably 0.
．． 05-10% by weight, more preferably 031-5% by weight
is selected. It is also possible to use a mixture of these adhesive components.

Furthermore, a small amount of an organic tin compound or the like is generally added as a catalyst to the silicone rubber layer.

The thickness of the silicone rubber layer should be as thin as possible from the point of view of tone reproducibility, and a certain degree of thickness is required from the point of view of printing durability and printing smudges, so the appropriate thickness is usually about 0.5 to 10μ. Yes, 1.0 to 3.0μ is desirable.

Silicone rubber swelling agents> The silicone rubber swelling agents used in the present invention include paraffinic hydrocarbons such as pentane, hexane, heptane, octane, nonane, and decane; cycloparaffinic hydrocarbons such as cyclopenkune, cyclohexane, and cyclo Petroleum fractionation products corresponding to single solvents such as hebutane, cyclooctane, cyclononane, cyclodecane, etc. or mixtures of their isomers, such as Isopar G1A, Isopar H1 Exol D100, Exol D110 (
(manufactured by Exxon Chemical Co., Ltd.) etc. can be used as useful solvents. Furthermore, any material other than paraffinic hydrocarbons may be used as long as it has the ability to swell the silicone rubber layer. For example, aromatic hydrocarbons such as toluene and xylene,
Aliphatic ketones such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, glycol ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, ethyl acetate, propyl acetate Also suitable as silicone rubber swelling agents are alkyl esters of aliphatic carboxylic acids such as butyl acetate, amyl acetate, hexyl acetate, methyl butyrate, ethyl butyrate, propyl butyrate, and the like. These aromatic hydrocarbons, aliphatic ketones, glycol ethers, and alkyl esters of aliphatic carboxylic acids can also be used as development accelerators. In the present invention, the amount of silicone rubber swelling agent used is 1 to 1.
65% by weight, preferably 2-50% by weight is suitable.

Development accelerator> Examples of development accelerators include organic solvents that swell or dissolve the photosensitive layer, such as alcohols, esters, ketones, ethers, aromatic hydrocarbons, halogenated hydrocarbons, and carboxylic acids. However, the solubility in water is 20%
The following solvents, such as benzyl alcohol, ethylene glycol monophenyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether,
Diethylene glycol dibutyl ether, 1-butoxy-2-propatol, phenylmethyl ether, cyclohexanol, cyclohexane, benzyl benzoate, dibutyl oxalate, diethyl malonate, dibutyl malonate, diethyl maleate, dibutyl maleate, etc. are used in the present invention. Especially suitable.

In the present invention, the amount of development accelerator used is 1 to 65% by weight,
Preferably, 2 to 50% by weight is appropriate.

Surfactant> A surfactant is used to uniformly mix the silicone swelling agent, development accelerator, and water.

Examples of surfactants include nonions such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerol U5 acid ester, and oxyethylene oxypropylene block polymer. Surfactants, fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates, alkylnaphthalene sulfonates, dialkyl sulfosuccinate ester salts, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl sulfate ester salts, etc. There are anionic surfactants such as alkylamine salts, quaternary ammonium salts, cationic surfactants such as polyoxyethylene alkylamine, and amphoteric ionic surfactants such as alkyl betaines, among others, anionic surfactants are suitable. There is.

These surfactants can be used alone or in combination of two or more. The appropriate amount of surfactant used in the present invention is 0.5 to 60% by weight, preferably 1 to 50% by weight.

Additionally, a polar third material can be added to stabilize the mixture of silicone swelling agent, development accelerator, water, and surfactant. Polar third substances include higher alcohols such as heptyl alcohol, octyl alcohol, nonyl alcohol, and decyl alcohol, as well as lactic acid esters, acetate esters, acetic esters, benzoate esters, and phthalate esters. However, among these, higher alcohols such as octyl alcohol, nonyl alcohol, and decyl alcohol are the most useful. The amount of the polar third substance used in the present invention is 0.1 to 40
Weight %, preferably 0.5 to 30 weight %, is suitable.

The content of water contained in the developer of the present invention is 30% by weight or more, and if it is less than 30% by weight, the content of the silicone rubber swelling agent or development accelerator in the developer is the necessary amount to play each role. becomes more than Therefore, not only is the silicone rubber layer in the non-image area susceptible to scratches during development, but it is also extremely dangerous and economically disadvantageous if it ignites for some reason. On the other hand, if the water content exceeds 95% by weight, the development speed will gradually decrease or development will become impossible.
It is desirable that the content be 5% by weight or less.

〔Example〕

The present invention will be explained in more detail below with reference to Examples.

Example 1 The following primer layer composition was applied to a smooth aluminum plate degreased in a conventional manner to a dry weight of 0.5 g/m' and dried.

Photosensitive unsaturated polyester obtained by polycondensation of p-phenylene diacrylic acid ester and 1,4-dihydroxyethyloxycyclohexane at a 1=1 (molar ratio) 10 parts by weight 1-Methyl-2-benzoylmethylene-β-naphthothiazoline 0 .6 parts by weight KBM-
603 (silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd., N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane) 0.5 parts by weight Methyl cellosolve acetate 150 parts by weight Toluene
150 parts by weight methyl cellosolve
Next, the aluminum plate coated with 150 parts by weight of the above composition was coated with Nuark's ET26V UDNS.
ULTRΔ-PLUS FLIP-TOP P
It was exposed to light for 30 counts using LATEMAKER. The thus obtained aluminum plate coated with a single layer of brimmer is coated with a developer or a mixed solvent for coating the photosensitive layer (methyl cellosolve acetate/toluene/methyl cellosolve = 4
/3/2 weight part ratio mixture), there was no dissolution. The following photosensitive composition was coated on the aluminum plate coated with one layer of the above-mentioned brimer so as to have a dry weight of 0.25 g/m', and then dried.

Photosensitive lower saturated polyester obtained by polycondensation of p-phinidia diacrylic acid ester and 1,4-dihydroxyethyloxycyclohexane (1=1 (mole ratio)) 10 parts by weight 1-methyl-2-benzoylmethylene-β-naphtho Thiazoline 0.6 parts by weight Sumitone Cyanine Blue V H514 (phthalocyanine blue pigment manufactured by Sumitomo Chemical Co., Ltd.) 2 parts by weight Methyl cellosolve acetate-1-400 heavy fliR toluene
300 parts by weight methyl cellosolve
200 parts by weight 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.

Shin-Etsu Silicone KS-709 () 30% by weight solution of luene > 30.0 parts by weight Shin-Etsu silicone curing catalyst CAT-PS o, 3 parts by weight Shin-Etsu silicone catalyst CA'r-FD 1.5 parts by weight Isopar G (Exxon Chemical Co., Ltd.) % Formula % A positive film was brought into close contact with the dampening water-free lithographic printing plate obtained as above, and the PLATBM manufactured by Nuark Co., Ltd.
After 30 counts of exposure with AKER, the developer pad was soaked with the following developer composition and rubbed for about 1 minute.
The photosensitive layer and silicone rubber layer in the unexposed areas were removed.

Isobutyl acetate 50 parts by weight Benzyl alcohol 10 times i Perex N
BL (38% aqueous solution of anion activator manufactured by Kao Atlas Co., Ltd.) 94 parts by weight water
50 parts by weight When this lithographic printing plate that did not require dampening water was attached to a printing machine with the dampening water supply device removed and printing was carried out, clean printed matter without background stains was obtained. The amount of water contained in this developer is approximately 53%.
Met.

Example 2 A positive film was brought into close contact with the photosensitive lithographic printing plate that did not require dampening water, prepared in Example 1, and exposed for 300 counts using an Eye Rotary Printer RP311 manufactured by Eye Graphics, followed by development with the following developer composition. When the pad was soaked with the powder and rubbed for about 1 minute, the photosensitive layer and silicone rubber layer in the unexposed areas were removed.

Methyl caprylate 70 parts by weight Benzyl alcohol 20 parts by weight Perex NBL (38% aqueous solution of anionic activator manufactured by Kao Atlas Co., Ltd.) 200 parts by weight Neugen ES-169 (nonionic activator manufactured by Dai-Kogyo Seiyaku Co., Ltd.) 20 parts by weight Water 100 parts by weight When printing was carried out using the water-free lithographic printing plate in the same manner as in Example 1, a clean printed matter without background stains was obtained. The amount of water contained in this developer was 55% by weight, and the flash point of the developer was measured using a Cleveland open flash point tester manufactured by Yoshida Scientific Machinery Co., Ltd., and found to be 91°C.

Example 3 A photosensitive lithographic printing plate that did not require dampening water and had been exposed in the same manner as in Example 2 was rubbed for about 1 minute with the developer composition shown below impregnated on a developing pad. The silicone rubber layer was removed.

Isopar G (manufactured by Exxon Chemical Co., Ltd.) 30 parts by weight Benzyl benzoate 30 parts by weight n-octyl alcohol 11 parts by weight 1 part Perex N
100 parts by weight of BL (38% aqueous solution of anionic activator manufactured by Kao Atlas Co., Ltd.) When this lithographic printing plate that did not require dampening water was printed in the same manner as described in Example 1, a clean printed matter with no scumming was obtained. .

Note that the amount of water contained in this developer was 36% by weight.

The flash point of this developer was measured in the same manner as described in Example 2 and found to be 51°C, which was an increase of approximately 7°C compared to the flash point of Isopar G, which was measured in the same manner as 44°C.

Example 4 A photosensitive lithographic printing plate that did not require dampening water and had been exposed in the same manner as in Example 2 was rubbed with the following developer composition on a developing pad for about 1 minute, and the silicone rubber layer in the unexposed areas was rubbed. has been removed. At this time, the photosensitive layer in the unexposed areas remained in the unexposed areas without being substantially dissolved.

Isopar G (manufactured by Exxon Chemical Co., Ltd.) 30 parts by weight Benzyl alcohol 30 parts by weight Rn-octyl alcohol 12 parts by weight Perex N
BL (38% aqueous solution of anionic activator manufactured by Kao Atlas Co., Ltd.) 100 double fluorescent parts When this lithographic printing plate, which does not require dampening water, was printed in the same manner as in Example 1, a clean print with no background stains was obtained. . Note that the amount of water contained in this developer was 36% by weight. The flash point of this developer was 48° C. when measured in the same manner as described in Example 2, and no continuous combustion occurred.

Example 5 The same operation as in Example 4 was performed except that a developer having the following composition was used.

Exol 0100 (manufactured by Exxon Chemical Co., Ltd.) 30 parts by weight Dimethyl phthalate 25 parts by weight Oleyl alcohol, u weight 11 tB Perex NBL (Kao Atlas Co., Ltd., anionic surfactant 38% aqueous solution) 100 parts by weight This lithographic printing plate that does not require dampening water When printing was carried out in the same manner as in Example 1, a clean printed matter without background stains was obtained. The amount of water contained in this developer was 32% by weight. This developer had no flash point.

Examples 6 to 8, Comparative Examples 1 and 8 A dampening water-less photosensitive lithographic printing plate exposed in the same manner as in Example 2 was soaked in a developing pad with the developer composition shown in the table below for about 1 minute. When rubbed, in Examples 6 to 8, the photosensitive layer and silicone rubber layer in the unexposed areas were removed, and when this was used for printing by the method described in Example 1, clean prints without background smear were obtained. Ta. On the other hand, in Comparative Example 1, the photosensitive layer and the silicone rubber layer in the unexposed areas were removed, but scratches were generated in the silicone rubber layer in the exposed areas, that is, the non-image areas during development. This is because the content of water in the developer is low. In addition, in Comparative Example 2,
The water content was too high, so it was not possible to develop it properly.

〔Effect of the invention〕

Since the developer of the present invention contains a predetermined amount of water, the silicone rubber layer in the non-image area is not scratched during development. In addition, automatic developing machines have a higher flash point and are safer than conventional developers that do not contain water or developers that have a low water content, so automatic developing machines are advantageous in terms of design for protection against exposure and can be inexpensive. I can do it.

Claims (1)

[Claims] A developer for a silicone rubber-layered photosensitive lithographic printing plate that does not require dampening water and comprises an organic solvent that dissolves or swells a photosensitive layer, an organic solvent that swells a silicone rubber layer, a surfactant, and 30% by weight or more of water.