JPS62280768A - Production of lithographic printing plate - Google Patents

Abstract

PURPOSE:To eliminate the need for selectively coating a treating agent for hydrophilicity importation to a non-image part by coating a specific compsn. on a base material, then drying the same to form an intermediate layer, coating a liquid adhesive agent dispersed therein with a photoconductive material on the intermediate layer and drying the coating to form a surface layer. CONSTITUTION:The compsn. prepd. by dissolving or dispersing the trihydroxysilane compd. expressed by CH2=CXCOO(CH2)nSi(OH)3 (X denotes a hydrogen atom or methyl group, n denotes 1-6 integer), polymn. catalyst for the trihydroxysilane compd., PVA of 30-60% degree of saponification, crosslinked matter of the alkaline salt of a polyacrylic acid and inorg. powder insoluble in an org. solvent into the org. solvent is coated on the base material. The coating is then dried to form the intermediate layer; thereafter, the liquid adhesive agent dispersed therein with the photoconductive material is coated on the intermediate layer and is dried to form the surface layer. The lithographic printing plate material which does not require coating of various treating agents only on the non-image part is thus obtd.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to a method for producing a lithographic printing plate material for use in electrophotographic engraving.

(b) Problems to be solved by the conventional technology and the invention Conventionally, as a lithographic printing plate material used in electrophotographic engraving, a zinc oxide photoconductive layer is provided on the surface of a substrate such as gold M foil 1 paper. something is being used. This is generally referred to as master paper, and it forms an electrostatic latent image on a zinc oxide photoconductive layer, and then applies an oleophilic developing powder (toner) to it using electrostatic W.
The image area is formed by adhering to the lithographic printing plate. By the way, since the zinc oxide photoconductive layer is exposed in the non-image area, it is necessary to make this area hydrophilic to prevent printing ink from adhering to it. It is done by applying it to the area.

However, after forming the image area, selectively applying a processing agent only to the non-image area is a cumbersome task, and the processing agent is also applied to the image area, making the image area hydrophilic. There was a danger that.

Therefore, the present invention has been made for the purpose of obtaining a lithographic printing plate material that does not require applying various processing agents only to non-image areas after forming an image area, and the lithographic printing plate obtained by the present invention The material is made hydrophilic to the non-image area by a conventional development process.

(d) Means and action for solving the problem, that is, the present invention, provides an organic solvent with the following formula: (i) General formula (■); CH,=CXCOO(CH2), Si (CH)3
(1) (wherein, X represents a hydrogen atom or a methyl group, and n
represents an integer from 1 to 6. ) A trihydroxysilane compound represented by (b) a polymerization catalyst for the trihydroxysilane compound, (c) M( ) [30 to 60% polyvinyl alcohol, and (d) crosslinking of an alkali salt of polyacrylic acid. things and (ho)
A composition prepared by dissolving or dispersing inorganic powder insoluble in organic solvent and The present invention relates to a method for producing a lithographic printing plate material, which comprises coating a layer and then drying to form a surface layer.

Component (A) used in the present invention is a trihydroxysilane compound represented by general formula (I). Specific examples of the trihydroxysilane compound include γ-methacryloxypropyltrihydroxysilane and γ-acryloxypropyltrihydroxysilane. The component used in the present invention is a polymerization catalyst for a trihydroxysilane compound. Specific examples of this polymerization catalyst include:
Examples include sodium acetate, sodium thiocyanate, triethylenetetramine, trimethylbenzylammonium hydroxide, 1,8-diazabicyclo(5,4°0)undecene-7 or its acetate, and amine compounds. A trihydroxysilane compound becomes a three-dimensional network polymer having a (0-5t-0) structure as a skeleton by its polymerization catalyst, and serves as a base for an intermediate layer of a lithographic printing plate material.

The component (c) used in the present invention has a saponification degree of 30 to 60.
% polyvinyl alcohol. If the degree of saponification exceeds 60%, it becomes insoluble in organic solvents, which is undesirable.
If it is less than 0%, the degree of hydrophilicity is low, which is not preferable. Polyvinyl alcohol mainly improves the hydrophilicity of the intermediate layer of lithographic printing plate materials.

Component (2) used in the present invention is a crosslinked product of an alkali salt of polyacrylic acid. Examples of the alkali salt of polyacrylate include sodium polyacrylate and calcium polyacrylate.

In the present invention, this polyacrylic acid alkali salt is crosslinked with a crosslinking agent. Examples of crosslinking agents include diglycidyl ether compounds such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether 1-glycerin diglycidyl ether, epichlorohydrin, and shrimp bromohydrin.

Haloepoxy compounds such as α-methylepichlorohydrin, aldehyde compounds such as glutaraldehyde and glyoxal, and isocyanate compounds such as 2.4-)lylene diisocyanate and hexamethylene diisocyanate are used. Cross-linked polyacrylic acid alkali salt is
This improves the hydrophilicity of the intermediate layer of the lithographic printing plate material and also improves the retention of dampening water.

The inorganic powder insoluble in the ff1i medium, which is the component (e) used in the present invention, may be any powder that is insoluble in the organic solvent or has extremely low solubility, such as zinc oxide, aluminum oxide, antimony oxide, calcium oxide, Chromium oxide, tin oxide, titanium oxide.

Metal or non-metal oxides such as iron oxide, copper oxide, lead oxide, bismuth oxide, magnesium oxide, manganese oxide, salts such as calcium carbonate 1 calcium sulfate, silicon compounds such as silicon dioxide, natural materials such as kaolin, hentonite, clay, etc. Pigment, aluminum.

Examples include various metal powders such as iron and zinc.

When an inorganic powder insoluble in an organic solvent is present in the intermediate layer of a lithographic printing plate material, it forms fine irregularities on the surface of the intermediate layer. Further, the particle size of the inorganic powder may be about 320 mesh baths, and the smaller the particle size is, the more suitable it is.

The composition used in the present invention can be obtained by uniformly dissolving or dispersing the above-mentioned components (a) to (e) in an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl alcohol, acetic acid, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, ethyl cellosolve,
Butyl cellosolve, acetic acid cellosolve, toluene, xylene.

Trichlorethylene, chloroform, etc. may be used alone or in combination.

In preparing the composition used in the present invention, for example, a trihydroxysilane compound as component (a), a polymerization catalyst for the trihydroxysilane compound as component (b), and (c)
After dissolving the component polyvinyl alcohol with a degree of saponification of 30 to 60% in an organic solvent, the (d) component crosslinked polyacrylic acid alkali salt and (e) component inorganic powder insoluble in the organic solvent are added. However, if necessary, a chelating agent, an R agent, a dye 1 thickener, etc. may be added, and foaming may be carried out without vigorous stirring.

The quantitative proportions of each component in the composition used in the present invention are preferably as follows. The amount of the polymerization catalyst for the trihydroxysilane compound may be sufficient as long as it is sufficient to polymerize the trihydroxysilane compound, and is usually 0.1 parts by weight per 100 parts by weight of the trihydroxysilane compound.
~5 parts by weight. The amount of polyvinyl alcohol is about 50 to 200 parts by weight, more preferably about 80 to 180 parts by weight, based on 100 parts by weight of the trihydroxysilane compound. If the amount of polyvinyl alcohol is less than 50 parts by weight, the hydrophilicity of the intermediate layer tends to be insufficient, and if it exceeds 4 parts by weight, the intermediate layer may melt and cause printing stains. The amount of the crosslinked polyacrylic acid alkali salt is about 50 to 200 parts by weight, preferably about 80 to 150 parts by weight, based on 100 parts by weight of the trihydroxysilane compound. If the amount of the alkali polyacrylic acid salt is less than 50 parts by weight, the ability to retain dampening water on the surface of the intermediate layer will be reduced and the hydrophilicity will be reduced. There is a tendency that the capacity to retain the energy does not increase, which tends to be uneconomical.

Further, the amount of inorganic powder insoluble in the organic solvent is 30 to 15 parts per 100 tfffi parts of the trihydroxysilane compound.
About 0 parts by weight, about 50 to 120 parts by weight. If the amount of the inorganic powder insoluble in the organic solvent is less than 30 parts by weight, variations in the unevenness of the surface of the intermediate layer of the lithographic printing plate material are likely to occur, and variations in the adhesion of the liquid adhesive applied later are likely to occur. There is a tendency to Further, even if the amount exceeds 150 parts by weight, the adhesion of the liquid adhesive applied later cannot be improved much, and adding more than this tends to be uneconomical.

The base material for applying the composition used in the present invention includes:
Any material may be used as long as it is inexpensive and satisfies the required performance as a lithographic printing plate, such as a foil or plate made of a fully bent element such as aluminum, copper, zinc, lead, or an alloy thereof; Polyester, polypropylene 1 polyimide, polyacrylonitrile, polycarbonate 2
polyamide, polyvinyl chloride, polyvinylidene chloride,
Plastic film or sheet molded products such as polystyrene and polyethylene, synthetic paper, and art paper.

Various materials such as coated paper, cardboard, thin paper, etc. can be used. Metal base materials include aluminum, zinc,
Iron etc. are suitable. Polyethylene, polyimide, and polycarbonate, which have relatively high dimensional stability, are suitable as the base material for Plus Sennox. As the paper base material, synthetic paper, coated paper, art paper, and cardboard are suitable.

When applying the composition used in the present invention to a metal substrate, 5-sulfosalicylic acid, ethylenediaminetetraic acid [1,I, lance-
Cyclohexane-1,2-diaminetetraacetic acid, butane-1,2,3,4-tetracarboxylic acid 1-propylenediaminetetraacetic acid, bencumethylenediaminetetraacetic acid,
Chelating agents such as cyclobencune-1,2-diaminetetraacetic acid, cyclohexane-1,4-diaminetetraacetic acid, and 2-hydroxytrimethylenediaminetetraacetic acid may be added to the composition used in the present invention. Further, the substrate does not need to be pretreated prior to application of the composition used in the present invention, unless the surface thereof is contaminated with oily substances. If necessary, the specific surface area of the substrate surface can be reduced by physically treating the surface of the substrate by wet or dry hoing, pole polishing, brush polishing, etc., or by chemically treating it by chemical conversion treatment with acid or alkali. Of course, there is no problem in increasing it.

After the composition is applied to the substrate in this manner, it is dried to form an intermediate layer on the substrate, and then a liquid adhesive is applied to this intermediate layer.

A photoconductive substance is dispersed in the liquid adhesive.

Photoconductive substances include powdered zinc oxide, silicon,
Kermanium, arsenic, tellurium, selenium, gallium arsenide,
Inorganic substances such as cadmium sulfide, cadmium selenide, lead sulfide, tellurium, gallium arsenide, selenium-tellurium mixed crystals, arsenic-selenium-tellurium mixtures, or verimide, oxathiazole.

Organic substances such as polyvinylcarbazole, polyvinylpyrene, polyvinyl acridine, polyacenaphthylene, and polyvinylanthracene can be used. In addition, when using an organic substance, it is common to use a sensitizer such as trinitrofluorene, triallyl carbonium salt, benzopyrylium salt, crystal bioleft, etc. in combination. This photoconductive substance imparts photoconductivity to the surface layer of the lithographic printing plate material, making it possible to form an electrostatic layer image.

The liquid adhesive in which the photoconductive substance is dispersed is one in which a high molecular weight polymer is dissolved in an organic solvent or water. As the polymer, methylcellulose, ethylcellulose, polyvinyl acetate, polyvinyl chloride, etc. are used.

Furthermore, as the organic solvent, methyl alcohol, ethyl alcohol, propyl alcohol, acetone, etc. are used.

The amount of photoconductive material in the liquid adhesive is 10% of the polymer
The amount is about 5 to 100 parts by weight, or about 10 to 50 parts by weight, based on the amount of Offfi. The amount of photoconductive material is 5
If it is less than part by weight, electrostatic 11&
tends to be less likely to form.

Moreover, if it exceeds 100 parts by weight, the adhesive force of the surface layer to the intermediate layer tends to decrease.

A surface layer is formed by applying this liquid adhesive onto the intermediate layer and evaporating the organic solvent or water.

A toner image is formed on the surface layer of the thus obtained lithographic printing plate material having a three-layer structure consisting of a base material, an intermediate layer, and a surface layer using an electrophotographic copying machine. After the toner image is formed, a lithographic printing plate is obtained by removing the surface layer in the non-image area using a welding agent, water, or the like. Therefore, since the intermediate layer is exposed in the non-image area and is highly hydrophilic, water adheres to the non-image area and ink adheres to the toner image, allowing good planographic printing. .

(d) Examples Example 1゜4 soffii parts of ethyl acetate, 600 parts of ethyl alcohol
Parts by weight, IB prepared by mixing 450 parts by weight of methyl isobutyl ketone, 100 parts by weight of T-methacryloxypropyltrihydroxysilane, 2fil1m of trimethylbenzylammonium hydroxide, and a saponification degree of 55.
After melting 100 parts by weight of polyvinyl alcohol (100 parts by weight), 100 parts by weight of a crosslinked product of sodium polyacrylate (manufactured by Order Kagaku ■, trade name Sumikagel) and 100 parts by weight of polyvinyl alcohol with a particle size of 10 to 15 μm.
100 parts by weight of silicon dioxide were added thereto, mixed and stirred to obtain a composition.

This composition was applied to a milk fat-completed aluminum sheet (JI
S^-1100, thickness 0.15 dragon 1 size 200 dragon x 30
0 Ken■) with a #6 bar coater and heated at 230℃.
was heated for 60 seconds to form an intermediate layer on the aluminum thin plate.

Furthermore, a liquid adhesive having the following composition was applied onto this intermediate layer using a #6 bar coater and dried at 100° C. for 60 seconds to obtain a lithographic printing plate material.

Zinc oxide: 30 parts by weight Ethyl cellulose: 60 parts by weight Ethyl alcohol: 500 parts by weight An electrophotographic copying machine was used to create a toner image on the surface of this lithographic printing plate material (Toner composition 2: Calhon plaque as colorant, polystyrene as binder, test pattern = 175) Line, halftone dots 3-75
%) and then immersed it in ethyl alcohol for 1 minute to remove the surface layer exposed in the non-image area.
A lithographic printing plate was obtained.

When this lithographic printing plate was printed on high-quality paper using a Heidel KORD printing machine, about 10,000 prints could be obtained without any background smearing or the like.

Example 2 In an organic solvent prepared by mixing 400 parts by weight of acetic acid and 1600 parts by weight of ethyl alcohol, 100 parts of T-methacryloxypropyltrihydroxysilane, 3 M parts of trimethylbenzylammonium, and polyvinyl with a saponification degree of 40%. After melting 80 parts by weight of alcohol, 90 parts by weight of a crosslinked product of sodium polyacrylate (manufactured by Custom Chemical @l, product name Sumikagel) and 55 parts by weight of titanium oxide with a particle size of 10 to 15 mmμ were added and mixed. , f! ! 1 stirring to obtain a composition.

This composition was prepared in Example 1. Using the same method as above, an intermediate layer was formed on a thin aluminum plate.

Then, a liquid adhesive having the following composition was applied to the intermediate layer in Example 1.
A lithographic printing plate material was obtained by coating and drying under the same conditions as above.

Tellurium and other ships 20 parts by weight Polyvinyl acetate 40 parts by weight Acetone
500 parts by weight A toner image (toner composition 2: carbon blank as colorant, polystyrene as binder, test pattern: 175 lines, halftone dots 3 to 75) was printed on the surface of this lithographic printing plate material using an electrophotographic copying machine.
%), the plate was immersed in acetone for 1 minute to remove the surface layer exposed in the non-image area to obtain a lithographic printing plate. When printing was carried out using this lithographic printing plate material under the same conditions as in Example 1, there was no occurrence of background smearing, and the result was about 10 mm.
I was able to obtain oo prints.

Example 3゜Ethyl acetate, 1 part by weight of sOO, 600ml of ethyl alcohol
ff, 450 parts by weight of methyl isobutyl ketone, and 100 parts by weight of cellosolve acetate, γ
- 100 parts by weight of acryloxypropyltrihydroxysilane, 2 parts by weight of trimethylbenzylammonium hydroxide, and 10 parts by weight of polyvinyl alcohol with a degree of saponification of 50%.
After melting 0 parts by weight, a crosslinked product of sodium polyacrylate (manufactured by Custom Kagaku ■) was prepared.

(Brand name Sumikagel) 50 parts by weight and particle size 10-15
30 parts by weight of mmμ barium sulfate was added and mixed.

A composition was obtained by stirring.

This composition was prepared in Example 1. Using the same method as above, an intermediate layer was formed on a thin aluminum plate.

Then, a liquid adhesive having the following composition was applied to the intermediate layer in Example 1.
A lithographic printing plate material was obtained by coating and drying under the same conditions as above.

Polyvinylcarbazole 25 parts by weight Crystal Bioleft (sensitizer) 1 part by weight Ethyl cellulose 40 parts by weight Ethyl alcohol
350 parts by weight A toner image (toner composition: carbon black as colorant, polystyrene as binder, test pattern: 175 lines, halftone dots 3 to 75%) was formed on the surface of this lithographic printing plate material using an electrophotographic copying machine. Thereafter, the plate was immersed in ethyl alcohol for 1 minute to remove the surface layer exposed in the non-image area to obtain a lithographic printing plate. Example 1 was carried out using this lithographic printing plate material. When printed under the same conditions as , there was no background smudge, and the result was approximately 10
We were able to obtain 000 prints.

(e) Effects of the invention The lithographic printing plate material obtained by the method of the invention has a base material-
It has a three-layer structure: an intermediate layer and a surface layer.

The intermediate layer is obtained by coating an aqueous solution composition with a specific composition and is hydrophilic, and the surface layer is obtained by coating a liquid adhesive containing a photoconductive substance and has a high toner receptivity. In good condition. Therefore, after forming a toner image on the surface layer, by removing the surface layer in the non-image area with an organic solvent or the like, the intermediate layer is exposed in the non-image area and the non-image area becomes hydrophilic. Of course, it goes without saying that the organic solvent used to remove the non-image area must not have any adverse effect on the toner i-image area. In the planographic printing plate thus obtained, water adheres to the non-image areas and ink adheres to the toner image areas, allowing good planographic printing.

As is clear from the above explanation, the lithographic printing plate material obtained by the method of the present invention is manufactured by the process of selectively applying a hydrophilic treatment agent to non-image areas, as in the conventional lithographic printing plate material (master vapor). is no longer necessary, and if the surface layer of the non-image area is simply removed by immersing the toner in an organic solvent or the like after forming the toner image (this can also be referred to as development treatment with an organic solvent or the like),
It has the effect of being able to easily print a lithographic printing plate.

Claims (1)

[Claims] In an organic solvent, (a) general formula (I); CH_2=CXCOO(CH_2)_nSi(OH)_
3(I) (wherein, X represents a hydrogen atom or a methyl group,
n represents an integer of 1 to 6. ) A trihydroxysilane compound represented by (b) a polymerization catalyst for the trihydroxysilane compound, (c) polyvinyl alcohol with a saponification degree of 30 to 60%,
(d) A crosslinked product of an alkali polyacrylic acid salt, and (e) an inorganic powder insoluble in an organic solvent. A composition obtained by dissolving or dispersing the following is applied to a base material, and then dried to form an intermediate layer. . A method for producing a lithographic printing plate material, comprising: thereafter applying a liquid adhesive in which a photoconductive substance is dispersed to the intermediate layer, and then drying it to form a surface layer.