JPH03291655A - Production of damping waterless photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To obtain a planographic printing plate having high smoothness and not causing the stain of the non-printing area by using a coating liq. for a primer layer contg. alkyl lactate. CONSTITUTION:An Al plate is especially preferably used as a substrate from the viewpoint of printing resistance. This Al plate is degreased by immersion in an aq. NaOH soln., washed, anodically oxidized in an aq. sulfuric acid soln., washed, immersed in an aq. sodium metasilicate soln., further immersed in water, washed and dried. A coating liq. for a primer layer contg. alkyl lactate is prepd. and dispersed with a sand grinding mill. The treated Al plate is coated with the coating liq., dried, uniformly exposed with an ultrahigh fension mercury lamp and further dried to form a primer layer. A planographic printing plate having superior smoothness and not causing the stain of the non-printing area is obtd.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a method for producing a photosensitive lithographic printing plate that does not require dampening water, and particularly relates to a method for producing a photosensitive lithographic printing plate that does not require dampening water, and in particular, a method for producing a photosensitive lithographic printing plate that does not require dampening water and is produced using a novel coating solvent for a primer layer. The present invention relates to a method for producing a lithographic printing plate.

[Conventional technology]

Conventionally, in lithographic printing, it has been necessary to perform printing by making use of the lipophilicity of the imaged areas and the hydrophilicity of the non-imaged areas, with a delicate balance of water and ink, and this requires considerable skill.

In other words, in the conventional printing method that requires dampening water, an image film is exposed to light through an image film on a plate material having an oleophilic photosensitive layer coated on a hydrophilic support, and then developed. A printing plate is prepared by providing an oil portion and a hydrophilic portion which is a non-printing portion. During printing, water is first transferred to the non-image area, and then ink is transferred. Ink does not adhere to non-print areas where water is present, but only to print areas. However, with this method, it is difficult to control the delicate balance between dampening water and ink, which can cause emulsification of the ink or mix the ink with the dampening water, resulting in poor ink density and background smearing, which is a major cause of horizontal paper. It had some major problems.

Furthermore, the transfer of dampening water to the printing material causes a change in the dimensions of the printing material, which also has the disadvantage that the sharpness of the image is impaired, especially when printing in multiple colors.

For this reason, attempts have been made to develop a lithographic printing plate that does not require dampening water. A waterless lithographic plate having a structure is disclosed, and a plate-making method is also described in which the photosensitive layer is dissolved in a developer to remove the upper silicone rubber layer to form an image area. Also, Special Publication No. 54-26923 and No. 5
No. 6-23150 has a structure similar to the above in that a silicone rubber layer is provided on a photosensitive layer on a support, but the photosensitive layer does not dissolve in a developer and the photosensitive layer and silicone rubber layer are separated by image exposure. The rubber layer causes photo-adhesion or photo-peeling,
A method for selectively swelling and removing only the silicone rubber layer is disclosed.

Furthermore, in the photosensitive lithographic printing plates that do not require dampening water as described above, a primer layer is often provided between the support and the photosensitive layer.

The primer layer brings the support and the photosensitive layer into close contact,
In particular, when the photosensitive layer is dissolved in the developer, the primer layer is exposed, so the ink receptivity and dyeability (after development, the image area is colored to distinguish between the image area and the non-image area. ) must be excellent. An example of a primer layer that satisfies these conditions is a primer layer formed by photocuring a layer made of a diazo resin and a hydroxyl group-containing polymer.

In addition to the above, the primer layer may also contain fillers such as titanium oxide and zinc oxide, antihalation agents, dyes for imparting printout properties, acid generators, and the like. In order to apply the primer layer onto the support, the primer layer is dispersed and dissolved in a suitable solvent and applied. Examples of the solvent used include methyl cellosolve, diethylene glycol glycol monomethyl ether, diethylene glycol dimethyl ether, and methyl ethyl ketone. However, these solvents have problems with the dispersibility of titanium oxide, zinc oxide, and the like. The surface of the primer layer obtained in such cases loses smoothness due to agglomeration of the filler, and in severe cases,
The particles become larger than the film thickness of the photosensitive layer and silicone layer coated on the primer layer, causing the silicone layer to be missing, and resulting in inconvenience as dotted stains on printed matter. In addition, there are problems such as toxicity, which is not desirable from an occupational health perspective.

[Problem to be solved by the invention]

Therefore, it is an object of the present invention to solve the problem of toxicity during production compared to conventional coating solvents, to have good dispersibility of fillers such as titanium oxide and zinc oxide, and to improve the surface of the resulting primer layer. An object of the present invention is to provide a method for producing a water-free photosensitive lithographic printing plate having excellent smoothness.

[Means to solve the problem]

The present inventors have provided a substrate with at least a primer layer, a photosensitive layer, and a silicone rubber layer in this order from the substrate side, and the primer layer is coated with a coating solution using a solvent containing a lactic acid alkyl ester to form a primer. It has been found that the above object can be distantly achieved by a method for producing a photosensitive lithographic printing plate that does not require immersion water and is characterized by providing a layer.

The present invention will be explained in more detail below.

In the present invention, any of a variety of known primer layers can be used as the primer layer. For example, the primer layer described in Japanese Patent Publication No. 1983-54219, which is made of epoxy resin, polyurethane resin, etc. and heat-cured using an appropriate curing agent, can be used as the primer layer. The primer layer or the primer layer described in JP-A-60-229031, such as a photo-cured layer made of a photodimerizable curable resin, etc., can be used.

Furthermore, a primer layer obtained by photocuring a layer mainly composed of a hydroxyl group-containing polymer and a diazo resin is also suitably used. Such hydroxyl group-containing polymers include alcoholic hydroxyl group-containing poly(meth)acrylic acid (hereinafter, both acrylic and methacrylic are collectively referred to as (meth)acrylic). An ester or amide of is preferably used.

Examples of monomers having alcoholic hydroxyl groups include 2-hydroxyethyl (meth)acrylate), N-(4
-hydroxyethylphenyl) (meth)acryla 5
and hydroxy-methyldiacetone (meth)acrylic acid. Particularly preferred is 2-hydroxyethyl (meth)acrylate.

Monomers copolymerizable with the above-mentioned hydroxyl group-containing monomers include (11) monomers having an aromatic hydroxyl group, such as N(4-
hydroxyphenyl) (meth)acrylamide, o-
1m-1p-hydroxystyrene, o-1m-1p-
Hydroxyphenyl (meth)acrylate (2) α, β of (meth)acrylic acid, maleic anhydride, etc.
-Unsaturated carboxylic acids, (3) methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, (meth)butyl acrylate, amyl (meth)acrylate, hexyl (meth)acrylate , cyclohexyl (meth)acrylate,
(meth)octyl acrylate, (meth)acrylic acid-2
- Substituted) alkyl (meth)acrylates such as chloroethyl, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate, N-dimethyla2noethyl (meth)acrylate, ( 4) (meth)acrylamide, N-methylol (meth)acrylamide, N-ethyl (meth)acrylamide, N-hexyl (meth)acrylamide, N-cyclohexyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, (Meth)acrylamides such as N-phenyl (meth)acrylamide, N-nitrophenyl (meth)acrylamide, N-ethyl-N-phenyl (meth)acrylamide, (5) Ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl Vinyl ethers such as vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, phenyl vinyl ether, etc. (6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate, vinyl benzoate, etc. (7) Styrene, α-methylstyrene , styrenes such as methylstyrene, chloromethylstyrene, (8) vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone, (9) olefins such as ethylene, propylene, isobutylene, butadiene, isoprene, etc. , αrRN-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, (meth)acrylonitrile, and the like. Particularly preferred are the above groups (1) to (3).

The amount of the hydroxyl group-containing monomer in the hydroxyl group-containing polymer is not particularly limited, but is preferably 5% to 95% by weight, particularly preferably 10% to 90% by weight.

The weight average molecular weight of the hydroxyl group-containing polymer of the present invention measured by GPC method is preferably 5,000 to 1,000,000 (in terms of styrene). If the value is lower than 5000, it may be attacked by the coating solvent or developer of the photosensitive layer even after exposure.
If the value is larger than 00000, it is difficult to select a coating solvent.

The proportion of the hydroxyl group-containing polymer in the primer layer is preferably 10 to 99% by weight, more preferably 40 to 99% by weight.
It is 97% by weight. In addition to the above-mentioned polymers, polyvinyl alcohol derivatives, epoxy resins, novolak resins, gelatin, cellulose, etc. can also be used as the hydroxyl group-containing polymer.

As the diazo resin, for example, Photographic Science and Engineering (Photo to
, Sci, Eng, ) No. 17 @, page 33 (1
973), U.S. Patent No. 2,063,631, U.S. Patent No. 2.
No. 679.498, same No. 3. Diazo compounds and active carbonyl compounds whose production methods are described in the specifications of No. 050.502, JP-A-59-78340, etc.
For example, a diazo resin obtained by condensing formaldehyde, acetaldehyde, benzaldehyde, etc. in an acidic medium such as sulfuric acid, phosphoric acid, or hydrochloric acid.
A diazo resin obtained by subjecting a diazo compound and a diphenyl ether derivative to a condensation reaction, the manufacturing method of which is described in Japanese Patent No. 4001, can be used.

The counter anion of the diazo resin used in the present invention is
It forms a stable salt with the diazo resin and contains an anion that makes the resin soluble in organic solvents.

These include organic carboxylic acids such as decanoic acid and benzoic acid;
Contains organic phosphoric acids and sulfonic acids such as phenyl phosphoric acid,
Typical examples include methanesulfonic acid, chloroethanesulfonic acid, dodecanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, mesitylenesulfonic acid and anthraquinonesulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, hydroquinone Sulfonic acid, 4-acetylbenzenesulfonic acid, dimethyl-5
Aliphatic and aromatic sulfonic acids such as sulfoisophthalate, 2.2', 4.4'-tetrahydroxybenzophenone, 1,2.3-)lyhydroxybenzophenone, 2
．． Hydroxyl group-containing aromatic compounds such as 2',4-) hydroxybenzophenone, halogenated Lewis acids such as hexafluorophosphoric acid and tetrafluoroboric acid, C/l 04 ,
Examples include, but are not limited to, perhalogen acids such as IO4. Gelper knee chromatography (GP)
The weight average molecular weight measured in C) is 200 to 10,000
(Styrene equivalent) is preferably in the range of 500 to 5000
The range is more preferable.

In the present invention, the proportion of the diazo resin in the primer layer is preferably 3 to 80% by weight, more preferably 5 to 60% by weight.

Furthermore, in the present invention, in addition to the above components, the primer layer may contain fillers such as titanium oxide or antihalation agents, colorants such as dyes and pigments, coating properties improvers,
Plasticizers, stabilizers, fat-sensitizing agents, etc. may be included in an amount not exceeding 10% by weight.

Examples of the dyes and coating properties improvers include Victoria Pure Blue BOH, Oil Blue #603, Oil Pink #312, Patent Pure Blue, Crystal Violet, Leuco Crystal Violet, Brilliant Green, Ethyl Violet, Methyl Green, Erythrosin B1 Basin Tsukushi. malachite green, leucomalachite green, m-cresol purple, cresol red, xylenol blue, Rhoda 1 2 ξ B1 aura ξ, 4-p-diethylaminophenyl straw nonaphthoquinone, cyano-p-diethylagonophenyl acetanilide Examples include triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes.

Examples of coating properties improvers include alkyl ethers (e.g. ethyl cellulose, methyl cellulose), fluorine surfactants, nonionic surfactants (e.g. "Bluronic L-64" (manufactured by Asahi Denka), "FC-430" ”
(manufactured by Sumitomo 3M), etc.

Examples of plasticizers for imparting flexibility and abrasion resistance to coating films include butylphthalyl, polyethylene glycol,
Examples include tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, oligomers of acrylic acid or methacrylic acid, and the like.

In addition, in order to improve the printing ink adhesion of images, various additives having hydrophobic groups, such as p-octylphenol/formalin novolac resin, pt-butylphenol/formalin novolak resin, pt-butylphenol/benzaldehyde resin, rosin, etc. Modified novolac resins such as modified novolak resins, and 0-naphthoquinonediazide sulfonic acid esters (esterification rate of ◯H groups of 20 to 70 mol %) of these modified novolac resins can be added and used.

As the filler, inorganic fillers such as aluminum oxide, zinc oxide, titanium oxide, and silica are used.

The above-mentioned photocurable diazo resin or a composition containing the same is dispersed and dissolved in an organic solvent together with other additives added as necessary, coated on a support, dried, and then exposed to light. The primer layer is formed by completely decomposing the diazo resin and curing it.

3 4 In the present invention, this existence! As the solvent (coating solvent), an organic solvent containing or containing lactic acid alkyl ester is used.

As the lactic acid alkyl ester, preferably used is an ester compound of lactic acid and a lower alcohol having 1 to 4 carbon atoms. Specifically, for example, lactate methyl ester, lactate ethyl ester, lactate propyl ester, lactate butyl ester, lactic acid Isobutyl ester, lactic acid acetyl ester, etc. are preferably used. In addition, when mixed with other solvents, the lactic acid alkyl ester is used in an amount of 30% by volume or more, preferably 50% by volume or more.

The thickness of the primer layer is 1■/d-~200■/d111
It is preferably 2, more preferably 3/d-~
lOO■/d-.

The photosensitive layer used in the present invention may be of any material as long as its solubility in a developing solution changes before and after exposure. Particularly preferred are photosensitive layers in combination with photosensitive substances. As the hydroxyl group-containing polymer, those used in the primer layer described above can be similarly used.

Examples of the photosensitive material to be used in combination include, for example, a photosensitive layer containing an 0-quinonediazide compound, a photoinsolubilizing photosensitive layer containing a diazo compound, a compound having an addition-polymerizable vinyl group, etc. Examples include layers.

Suitable 0-naphthoquinonediazide compounds include naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride and phenol or cresol-formaldehyde as described in U.S. Pat. No. 3,046,120. There are esters with resins. Other useful 0-
Examples of naphthoquinonediazide compounds include esters of pyrogallol-acetone resin and 0-naphthoquinonediazide sulfonic acid chloride described in U.S. Pat. Ester of polyhydroxyphenyl resin and 0-naphthoquinonediazide sulfone 56 acid chloride described in JP-A No. 561045, homopolymer of p-hydroxystyrene as described in JP-A-50-113305, or others. 0-naphthoquinonediazide sulfonic acid chloride is ester-reacted with a copolymer with a copolymerizable monomer, Japanese Patent Publication No. 49-17481
Examples thereof include a reaction product of a polymer product of a styrene monomer and a phenol derivative and 0-naphthoquinonediazide sulfonic acid, and an ester of polyhydroxybenzophenone and 0-naphthoquinonediazide sulfonic acid chloride.

The amount of the quinonediazide compound in the photosensitive layer is 10 to 50% by weight, more preferably 20 to 40% by weight.

As the diazo resin suitably used, those used in the primer layer described above can be used in the same manner. The amount of diazo resin in the photosensitive layer is 5 to 75% by weight, preferably 10 to 75% by weight.
It is 50% by weight. In addition, examples of compounds having an addition polymerizable vinyl group are shown below, but are not limited thereto.

Specific examples include ethylene glycol diacrylate,
Triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexa Acrylic acid esters such as acrylate and glycerol acrylate, methacrylic acid esters in which the acrylate of these exemplary compounds is replaced with methacrylate, itaconic acid esters in which itaconate is similarly replaced, crotonate esters in place of crotonate, maleic esters in place of maleate, etc. Further examples include hydroquinone di(meth)acrylate, resorcin di(meth)acrylate, pyrogallol triacrylate, and the like.

The photosensitive layer containing the above addition-polymerizable vinyl group-containing compound is combined with a known sensitizer and an activator that generates active radicals.

The amount of the compound having an addition polymerizable vinyl group in the photosensitive layer is 5 to 75% by weight, preferably 10 to 50% by weight.
It is. The amount of the sensitizer and activator to be combined is 0.05 to 0.05 to the compound having an addition polymerizable vinyl group.
20% by weight, preferably from 0.2 to 10% by weight, and the active agent from 0.5 to 70% by weight, preferably from 1 to 30% by weight.

In the present invention, in addition to the above components, the photosensitive layer includes a coloring agent,
It may also contain coating properties improvers, plasticizers, stabilizers, etc. in an amount not exceeding 10% by weight.

As the above additives, those used in the primer layer can be used in the same manner.

In the present invention, a silicone rubber layer is further provided on the photosensitive layer, and the silicone rubber used in the silicone rubber layer is preferably linear or crosslinked organopolysiloxane. The organopolysiloxane usually has a molecular weight of from 100,000 to several hundred thousand, and is moderately crosslinked in the form of a liquid, wax, or rice cake at room temperature. The organopolysiloxanes are classified into condensed type and addition type depending on the method of crosslinking.

In the condensed type, crosslinking is performed by a condensation reaction, and water, alcohol, organic acid, etc. are released by the reaction. Particularly useful condensation type silicone rubbers include a mixture of a linear organopolysiloxane having hydroxyl groups at both ends or a part of the main chain and a silicone crosslinking agent, or one in which the hydroxyl groups are reacted with a silicone crosslinking agent. In either case, adding a condensation catalyst is advantageous in terms of crosslinking speed.

The organopolysiloxane has the following repeating units in its main chain.

R.

1,5i-0+-z In the formula, Ro and R2 are alkyl, aryol, alkenyl, or a combination thereof, each of which may have a substituent such as a cyano group, a halogen atom, or a hydroxyl group, and a methyl group or a phenyl group. , a vinyl group, and a tri-90 flufluoropropyl group, and a methyl group is particularly preferred.

The above-mentioned silicone crosslinking agents include so-called acetic acid-removal type, oxime-elimination type, alcohol-elimination type, deamination type, which have a functional group represented by -○H (in the formula, R and R' are alkyl groups); Examples include condensation type silicone crosslinking agents such as dehydrated type. Examples of such crosslinking agents include tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, phenyltriacetoxysilane, dimethyldiacetoxysilane,
Diethyldiacetoxysilane, vinyltriacetoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, methyltris(acetoneoxime)silane, methyltri(N-methyl,
Examples include N-acetylamino)silane, vinyltri(methylethylketoxime)silane, methyltri(methylethylketoxime)silane, and oligomers thereof.

All of these crosslinking agents are organopolysiloxane 10
The amount is preferably in the range of 0.5 to 30 parts by weight relative to 0 parts by weight.

Examples of the condensation catalyst include organic carboxylic acids, titanate esters, naphthenic acids, and the like.

The addition type refers to unsaturated groups in the main body, such as vinyl groups (CH
-CHz) by the addition of the (S i -H) group in the crosslinking agent to cause crosslinking.

Specifically, examples include vinyl group-containing organopolysiloxanes, hydrogenated organopolysiloxanes, and the like mixed with platinum-based catalysts (for example, chloroplatinic acid).

The organopolysiloxane has repeating units similar to those of the condensed type in the main chain.

For the silicone rubber layer, it is possible to use either or both of condensation type and addition type silicone rubber.

1 2 It is also possible to use a condensed bracket addition type organopolysiloxane having a hydroxyl group, an unsaturated group, etc.

Among the commercial products available as the silicone rubber according to the present invention, preferred examples include KS-705F and K manufactured by Shin-Etsu.
E-41, 42, 44, Toshiba Silicone (manufactured) YE-5
505, YF3057, Toshi Silicone (manufactured by) SH-7
Condensation type silicone rubber such as 81, PRX-305, 5H-237 and Shin-Etsu KS-837, KE-103, K
E-106, KE-1300, Toshiba Silicone (manufactured by) T
SE-3032, RTU-B, Toshi Silicone (manufactured by) S
Examples include addition type silicone rubber such as H-9555.

Furthermore, for the purpose of improving the strength of the silicone rubber, inorganic fillers such as silica, titanium oxide, and aluminum oxide may be added, and silica is particularly preferably used.

From the viewpoint of dispersibility or dispersion stability, such fillers preferably have an average particle diameter of 500 nm or less.

In the present invention, the thickness of the silicone rubber layer is preferably as thin as possible from the point of view of image quality and developability, but on the other hand, a certain degree of thickness is required from the point of view of printing durability, printing stains, etc. /dm” to 50■/dm” is preferable, and 5■/dm
- to 30 .mu./dm2 is more preferable.

In the present invention, an adhesive layer made of, for example, epoxy resin may be provided between the photosensitive layer and the silicone rubber layer, and the adhesive layer may also contain various reactive crosslinking agents, silane coupling agents, etc. , and the thickness of the adhesive layer is 0.0
2■/dm'' to 1■/dmZ is preferred.

Furthermore, the photosensitive lithographic printing plate that does not require dampening water of the present invention may be provided with a protective layer on the silicone rubber layer, and the protective layer may be provided using a polypropylene film or the like described in Japanese Patent Publication No. 61-614. How to date and JP-A-61-
A method of applying a high molecular weight polymer described in Japanese Patent No. 27545 is known.

As the support used in the present invention, any support can be used as long as it has the flexibility to be set in a common lithographic printing machine and can withstand the load applied during printing, including the layer structure. There are no particular restrictions. Examples include papers such as coated paper, metal plates such as aluminum plates, and plastic films such as polyethylene terephthalate.

The substrate used in the present invention is preferably an aluminum plate or a composite material of aluminum foil and other materials, and from the viewpoint of printing durability, an aluminum plate is particularly preferable.

Particularly in the present invention, it is particularly preferable that the surface of the aluminum plate or aluminum foil is anodized and further treated with silicate. At that time, the silicic acid treatment, for example,
It is carried out by immersion in an aqueous sodium silicate solution with a concentration of 0.1 to 10% at a temperature of 30 to 95°C for 1 second to 2 minutes, and preferably then immersed in water at a temperature of 40 to 95°C for 10 seconds to 2 minutes. It is processed. The thickness of the substrate is preferably 0.1 to 0.3 m.

After imagewise exposing the photosensitive lithographic printing plate that does not require dampening water, prepared as described above, it is developed with a developer to dissolve the photosensitive layer and removed along with the silicone rubber layer above it, resulting in the primer layer being exposed as an image area. Then, a photosensitive lithographic printing plate that does not require dampening water is formed.

In this case, it is preferable to dye the image area with a cationic dye such as crystal violet, Victoria Blue BOH, and Astrazone Lesotho during or after development.

The light source used for exposure may be any general-purpose light source including ultraviolet rays of 180r+n+ or more and visible light, but carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, etc. are particularly preferred.

The developer used in the development process includes water, the following polar solvents, alkaline compounds such as amines, surfactants, and, if necessary, aliphatic hydrocarbons (hexane, heptane, etc.).
“Isopar E, H, G” (trade name of aliphatic hydrocarbons manufactured by Esso Chemical) or gasoline, kerosene, etc.), aromatic hydrocarbons (toluene, xylene, etc.) or halogenated 5 6 hydrocarbons (triclene, etc.) ) is added.

) Ethers (methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl calpitol, ethyl carpitol, butyl carpitol, dioxane, etc.) Ketones (acetone, methyl ethyl ketone, etc.) Esters 11 (ethyl acetate, methyl cellosolve acetate, cellosolve acetate, carpi Tall acetate, etc.) Also, the developing solution is a developer containing water as a main component, such as those described in JP-A-61-275759, etc., containing 30% by weight or more of water, preferably 50% by weight or more. A developer containing an organic solvent and a surfactant in an amount of 98% by weight can also be used, and a developer containing an alkaline agent can also be used.

Development can be carried out by various known methods, such as rubbing with a developing band containing a developer as described above, or pouring a developer onto the printing plate and then rubbing with a developing brush.

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

〔Example〕

(Examples 1 to 4) (Comparative Examples 1 to 2) Manufacture of aluminum plate a> An aluminum plate with a thickness of 0.24 m was immersed in a 3% aqueous sodium hydroxide solution to degrease it, and then washed with water. , anodized in a 32% sulfuric acid aqueous solution at a temperature of 30°C and 5 A/d2 for 10 seconds, and then washed with water, immersed in a 2% sodium metasilicate aqueous solution at a temperature of 85°C for 37 seconds, and then anodized at a temperature of 90°C. It was immersed in water (pH 8.5) at ℃ for 25 seconds, washed with water, and dried to obtain aluminum plate a.

Next, a primer layer coating solution with the composition shown below was prepared and dispersed for 1 hour using a sand grind kettle (S, G, I).
It was applied to an aluminum plate a, dried at 857°C for 3 minutes, and heated to 101°C using an ultra-high pressure mercury lamp every 3 days.
The entire surface was exposed to light of 000/-. It was further dried at 100° C. for 4 minutes to form a primer layer with a thickness of 4 μm. At this time, in order to examine the smoothness of the obtained primer layer, the surface gloss was measured using a gloss meter (Gloss Checker IG-310 manufactured by Horiba, Ltd.). The results are shown in Table-2.

Next, examples of synthesizing the hydroxyl group-containing polymer and diazo resin used in the primer layer and photosensitive layer will be shown.

(Synthesis example) <Synthesis example of hydroxyl group-containing polymer 10> 29.3 g of 2-hydroxyethyl methacrylate in a mixed solvent of 65 g of acetone and 65 g of methanol under a nitrogen stream
(0,225 mol) methyl methacrylate 27.5 g
(0,275 mol) and 1.23 g of azobisisobutyronitrile were dissolved, and while stirring this mixture, 60
The mixture was refluxed at ℃ for 6 hours. After the reaction was completed, the reaction solution was poured into water to precipitate the polymer compound, and vacuum-dried at 50° C. day and night.

Synthesis of hydroxyl group-containing polymers 2 to 6> Hydroxyl group-containing polymers 2 to 6 in the same manner as hydroxyl group-containing polymer 1
6 was synthesized. Table 1 below shows the monomers and compositions (mol%) used.

9 0 <Synthesis of diazo resin-1> p-diazodiphenylamine sulfate 14.5 g (50
mmol) was dissolved in 40.9 g of concentrated sulfuric acid under water cooling. 1.35 g (45 mmol) of paraformaldehyde was gradually added to this reaction solution so that the reaction temperature did not exceed 10°C.

This reaction mixture was added dropwise to 500 n+J of ethanol under water cooling, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was washed with 100 m7! of pure water, and to this solution was added a cold concentrated aqueous solution containing 6.8 g of zinc chloride.

The resulting precipitate was filtered, washed with ethanol, and washed with 1
50m7I was dissolved in pure water. To this liquid was added a cold concentrated aqueous solution in which 8 g of ammonium hexafluorophosphate was dissolved. The resulting precipitate was collected by filtration, washed with water, and then dried to obtain diazo resin-■.

(Primer layer composition> 1) Diazo resin - 110 parts 2) Hydroxyl group-containing polymers 1 to 4 90 parts 3) Zinc oxide 50 parts 1 2 4) Solvent 850 parts The combinations of hydroxyl group-containing polymers and solvents are shown in Table 2. .

Next, a photosensitive composition having the following composition was coated on the primer layer at a dry weight of 3 .mu./dm@2 and dried in hot air at 80.degree. C. for 2 minutes to form a photosensitive layer.

(Photosensitive layer composition) 1> Diazo resin - 150 parts 2) Hydroxyl group-containing polymer 5 50 parts 3) Victoria Pure Blue BOH 1 part 4) Lactic acid methyl ester
900 parts of the silicone rubber composition shown below was then applied onto the photosensitive layer at a dry weight of 1.8 g/rrr, and dried in hot air at 90° C. for 10 minutes.

(Silicone rubber layered bottom material) Dimethylpolysiloxane having hydroxyl groups at both ends (molecular weight 52,000) 100 parts triacetoxymethylsilane 10 parts dibutyltin laurate 0.8 parts "Isoper E" (manufactured by Esso Chemical) 900 parts Then, a single-sided matted polypropylene film with a thickness of 5 μm was placed on the silicone rubber layer.
A photosensitive lithographic printing plate that does not require dampening water was obtained.

After vacuum-adhering a positive film to the top surface of the above plate material, a metal halide lamp was used as a light source and a 230mJ
/c+a exposure. Then, the following developer solution at 27°C -
After being immersed in 1 for 1 minute, standard development is performed by rubbing the surface of the plate material with a pad impregnated with developer, and the silicone rubber layer and photosensitive layer in the unexposed areas are removed, and the halftone dots are reproduced well. A printing plate was obtained.

The image area of the above printing plate could be vividly dyed by applying a dyeing solution having the composition shown below to a cloth, rubbing the plate lightly, and then washing with water.

(Developer solution-1) β-anilinoethanol 0.5 parts Propylene glycol 1.0 parts p-tert-butylbenzoic acid 1.0 parts Potassium hydroxide
1.0 parts 3 4 Polyoxyethylene lauryl ether 0.1 parts Potassium sulfite 2.0 parts Potassium metasilicate 3.0 parts Water
91 parts (staining liquid) "Tsurfit" 20 parts (Kuraray Sobrene Chemical special solvent) "Rheodor TW-0120" (Kao ■ surfactant) 0.5 parts Benzyl alcohol 5.0 parts Victoria Pure Blue BOH 1.0 parts water
100 copies Next, the obtained waterless lithographic printing plate was transferred to a Heidelberg GTO with the dampening water supply device removed.
Installed on Printing II, Toyo Ink, TOYOKING
Printing was performed using ULTRA TKU Aquares G black ink, and the presence or absence of dotted stains in non-print areas was examined. Table 2 shows the results.

5 [Effect of the invention] From the results shown in Table 2, when the lactic acid alkyl ester of the present invention is used as a coating solvent for the brimer layer, a water-free photosensitive lithographic printing plate with good smoothness and no staining in non-image areas can be produced. It is also possible to obtain excellent effects that are favorable in terms of occupational health.

Claims (1)

[Claims] A substrate is provided with at least a primer layer, a photosensitive layer, and a silicone rubber layer in this order from the substrate side, and the primer layer is provided by applying a coating liquid using a solvent containing a lactic acid alkyl ester. Method for producing photosensitive lithographic printing plates that do not require dampening water