JPH04190360A - Photosensitive planographic printing plate needing no damping water - Google Patents

Abstract

PURPOSE:To detect the printing plate in the title with a coating defect inspection device using He-Ne laser and make it superior in exposure visible picture quality by containing a color to color with growth of said in a photosensitive layer and a color in which absorbancy in 633nm is more than 50% of the absorbancy in the maximum absorption wave length. CONSTITUTION:In a damping water unwanted photosensitive planographic printing plate having at least a primer layer, a photosensitive layer and a silicone rubber layer in this order from the side of a support body on the support body, the photosensitive layer has at least a color to color with growth of said and a color in which absorbancy in 633nm is more than 50% of absorbancy in the maximum absorption wave length. It is favorable that 0.1 - 20 weight% of the color to color with growth of said is contained in the photosensitive layer. Additionally, 0.1 - 10 weight% of the color in which absorbancy in 633nm is 50% or mor of absorbancy in the maximum absorption wave length is contained in the photosensitive layer. Consequently, it is possible to detect the system using coloring colors with a coating defect inspection device, and it is superior in exposure visible picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate that does not require dampening water, and more particularly to a photosensitive lithographic printing plate that does not require dampening water and contains a color-forming dye.

[Prior Art] In recent years, attempts have been made to develop lithographic printing plates that do not require dampening water. Water-free photosensitive lithographic printing plates are known.

Even with such photosensitive lithographic printing plates that do not require dampening water, exposure is required to facilitate alignment between film originals when performing so-called "multi-sided printing" in which multiple film originals are printed one after another by changing their positions. It is necessary to be able to distinguish between the exposed area and the unexposed area.

For this reason, a visible image is usually formed by exposure (hereinafter referred to as "exposure visible imageability"), but for this purpose, dyes whose color tone changes with the generation of acid are generally used. It is well known to use In particular, color-developing dyes that develop color upon generation of acid are often used because the boundaries between exposed and unexposed areas can be clearly distinguished after exposure compared to fading dyes.

Problems to be Solved by the Invention] By the way, in the production of photosensitive lithographic printing plates that do not require dampening water as described above, in order to inspect coating defects in the production line, scanning exposure using a He-Ne laser is performed. A coating defect inspection device that detects coating defects based on changes in reflectance is often used. However, when using the above-mentioned color-forming dye, in the unexposed area, such a dye is He
There is no or insufficient absorption at 633 nm, which is the oscillation wavelength of the -Ne laser, and as a result, there was a drawback in that it was not suitable for coating defect inspection.

Therefore, the object of the present invention is to provide a photosensitive lithographic printing plate that does not require dampening water and is detectable by a coating defect inspection device using a He-Ne laser and has excellent exposure visible image properties in a system using a color-forming dye. It is about providing.

[Means for Solving the Problems] In view of the above-mentioned problems, the present inventors have conducted extensive research and found that the above object of the present invention is to form at least a brimer layer, a photosensitive layer, and a silicone rubber layer on a support from the support side. In the photosensitive lithographic printing plate that does not require dampening water, the photosensitive layer comprises at least a) a dye that develops color upon generation of acid, and b
) It has been found that this can be achieved by providing a photosensitive lithographic printing plate that does not require dampening water and is characterized by containing a dye whose absorbance at 633 nm is 50% or more of the absorbance at the maximum absorption wavelength.

The present invention will be explained in more detail below.

In the present invention, the dyes contained in the photosensitive layer that develop color upon generation of acid (hereinafter referred to as dye It(a)) include the following.

Below margin 1 1-4-Limethyl yellow orange ■ Ethyl orange a- Naphthol olent Methyl red p-Aminoazobenzene 4-Phenylazodiphenylamine Methyl orange Such a dye is preferably 0.1 to 20% by weight in the photosensitive layer. Contains.

Furthermore, the dye whose absorbance at 633 nm is 50% or more of the absorbance at the maximum absorption wavelength (hereinafter referred to as dye (b)) is preferably a dye whose absorbance at 633 nm is 60% or more of the absorbance at the maximum absorption wavelength. used. Examples of such dyes include Eisen Diamond Green GH (Brilliant Green).
, Eisens Viron Violet C-RH, Eisens Viron Red C-DH, Malachite Green, Dia Resin Blue A, Dia Resin Blue C1 Dia Resin Blue P, Orient Oil Blue #603, Direct Dark Green B A, Food Blue No. 1 , Eisen Brilliant Basic Cyanine 6GH, Eisen Brilliant Milling Green B1 Eisen Victoria Blue B
Examples include Eisen Methylene Blue BHCOnC, Eisen Chiron Pure Pull-5GH 200%, Eisen Methylene Blue FZ, and Oil Blue. Preferred examples include Brilliant Green, Malachite Green, and Eisen Victoria Blue BH.

The above dye (b) is preferably contained in the photosensitive layer in an amount of 01 to 10% by weight.

In the present invention, the photosensitive layer used is the above dye (a
) and dye (b), and any material that changes its solubility in a developer before and after exposure can be used.

Specifically, for example, 0-quinonediazide compound, 0-
Examples include a photo-insolubilizable photosensitive layer containing a nitrobenzyl carbinol ester compound, a diazo compound, a compound having an addition-polymerizable vinyl group, and the like.

The above-mentioned 0-quinonediazide compounds are compounds having at least one 0-quinonediazide group, preferably an 0-benzoquinonediazide group or an 0-naphthoquinonediazide group, and include known compounds of various structures, such as those described by Jay Kosar [ Light Sensitivity Systems” (published by John Wiley & Sams, 1965)
Compounds described in detail on pages 339 to 353 are included.

For example, various hydroxyl compounds and benzoquinone-1
, 2-diazide sulfonic acid, naphthoquinone-1,2-diazide sulfonic acid, and the like. Examples of the hydroxyl compound used include condensation resins of phenols such as phenol, cresol and pyrogallol and carbonyl group-containing compounds such as formaldehyde, benzaldehyde and acetone, particularly resins obtained by condensation in the presence of an acidic catalyst.

As a photosensitive layer containing a diazo compound, Japanese Patent Application No. 1-104
A photosensitive layer shown in the specification of No. 286, which contains a diazo resin and a (meth)acrylic acid ester having a hydroxyl group or an amide-containing polymer as essential components, is preferred.

In the present invention, acrylic compounds and methacrylic compounds are collectively referred to as "(meth)acrylic...J".

In the case of such a photosensitive layer, the proportion of the diazo resin in the photosensitive layer is preferably 1 to 90% by weight, more preferably 3% by weight.
~60% by weight.

Examples of compounds having an addition-polymerizable vinyl group include compounds having a boiling point of 100°C or higher under normal pressure and having two or more polymerizable terminal ethylene groups, such as unsaturated carboxylic acids, unsaturated carboxylic acids, and fatty acids. esters with group polyhydroxy compounds, esters between unsaturated carboxylic acids and aromatic polyhydroxy compounds, unsaturated carboxylic acids and polyhydric carboxylic acids, and polyhydric hydroxy compounds such as the aforementioned aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds. Examples include esters obtained by esterification reactions with compounds, and are specifically described in JP-A-59-71048 and the like.

In the present invention, all of the photosensitive layers listed above can be used, but a photosensitive layer containing a diazo resin is preferred from the viewpoint of adhesion to the brimer layer.

In addition, in the present invention, in addition to the above-mentioned materials, known exposure-visible image agents, coating properties improvers, etc. may be added to the photosensitive layer as needed to improve the developable visible image property, the exposed visible image property, and the like. Coating properties can be improved.

Further, in the present invention, it is preferable that the photosensitive layer contains a hydroxyl group-containing polymer. As such a hydroxyl group-containing polymer, an alcoholic hydroxyl group-containing poly(meth)acrylic acid ester or amide is preferably used.

Examples of polymers having alcoholic hydroxyl groups include 2-hydroxyethyl (meth)acrylate, N-(4
-Hydroxyethylphenyl)methacrylamide, hydroxymethyldiacetone(meth)acrylamide, and the like having structural units derived from monomers such as (meth)acrylamide and the like. In particular, polymers having structural units derived from 2-hydroxyethyl (meth)acrylate are preferred.

The alcoholic hydroxyl group-containing polymer may be a copolymer (the copolymer monomers include (1) a monomer having an aromatic hydroxyl group, such as N-(4
-Hydroxyphenyl)(meth)acrylamide, o-
α, β of 1m-1p-hydroxymethylene, o-1m-1p-hydroxyphenyl (meth)acrylate, (2) (meth)acrylic acid, maleic anhydride, etc.
-Unsaturated carboxylic acids, (3) methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (
meth)acrylate, amyl(meth)acrylate, hexyl(meth)acrylate, octyl(meth)acrylate, 2-chloroethyl acrylate, 2-hydroxyethyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, glycidyl(meth)acrylate acrylate, optionally substituted alkyl (meth)acrylate such as N-dimethylaminoethyl (meth)acrylate, (4) (meth)acrylamide, N-methylol (meth)acrylamide, N-ethylacrylamide, N-hexyl Optionally substituted (meth)acrylamides such as methacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide, (5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl 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) Styrenes such as styrene, α-methylstyrene, chloromethylstyrene, (8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone, (9) ethylene, propylene, Examples include olefins such as inbutylene, butadiene, isoprene, (10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile, and the like. Particularly preferred is (3).

The thickness of the photosensitive layer is 0.1mg/drrr ~ 30mg/d
rr? is preferable, 0.5mg/drrr ~ 10m
g/drr? is more preferable.

In the photosensitive lithographic printing plate that does not require dampening water of the present invention, a brimer layer is provided between the support and the photosensitive layer.

The brimer layer is cured before coating the photosensitive layer, and such curing can be done by either heat curing or photo curing.

Examples of thermosetting resins include epoxy resins and urethane resins disclosed in Japanese Patent Publication No. 61-54219.

As the photocurable type, those consisting of a combination of a photopolymerization initiator, an ethylenically unsaturated monomer or oligomer, and a binder resin are preferably used.

The ethylenically unsaturated monomer or oligomer is a compound having a boiling point of 100° C. or higher under normal pressure and containing two or more polymerizable terminal ethylene groups, and various known ones can be used. For example, unsaturated carboxylic acids, esters of unsaturated carboxylic acids and aliphatic polyhydroxy compounds, esters of unsaturated carboxylic acids and aromatic polyhydroxy compounds, unsaturated carboxylic acids and polycarboxylic acids, and the aforementioned aliphatic Examples include esters obtained by esterification reactions with polyhydroxy compounds such as polyhydroxy compounds and aromatic polyhydroxy compounds, and are specifically described in JP-A-59-71048, such as diethylene glycol Di(meth)acrylate, triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol triacrylate, hydroquinone di(meth)acrylate
Acrylate, pyrogallol triacrylate, 2.2
' -bis(4-acryloxy-jethoxyphenyl)
Examples include propane. In addition, ethylene bis (
(meth)acrylamide, hexamethylenebis(meth)acrylamide, etc., vinyl urethane compounds, epoxy(meth)acrylate, etc. can be mentioned.

The amount of the ethylenically unsaturated monomer or oligomer in the brimer layer is 10 to 90% by weight, preferably 20 to 80% by weight.

In addition, as a photopolymerization initiator, conventionally known ones can be used (for example, benzoin, benzoin alkyl ether,
Benzophenone, anthraquinone, benzyl, Michler's ketone, a complex system of hiimidazole and Michler's ketone, etc. are all suitable (can be used).

The amount of the photopolymerization initiator in the brimer layer is 01 to 20% by weight, preferably 0.2 to 10% by weight.

In addition, suitable binder resins include polyester, polyurethane, (meth)acrylic copolymer, polyamide, polyvinyl formal, epoxy resin,
Examples include polyvinyl alcohol derivatives.

Further, two or more of these materials may be used as a blend, and block or graft polymers of these materials are also preferably used. Particularly preferably, block polymers of polyester and polyurethane are used.

The proportion of the binder resin in the brimer layer is
It is usually 10 to 99% by weight, preferably 30 to 97% by weight.

In the present invention, in addition to the above components, the primer layer may contain other fillers or antihalation agents, colorants such as dyes and pigments, coating improvers, plasticizers, stabilizers,
It may also contain an oil sensitizing agent or the like in an amount not exceeding 10% by weight. It is also possible to use various conventionally known polymers, such as polyamide and polyurethane, which are usually used in primer layers.

Examples of dyes that can be included in the primer layer 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 Basic Tsushin, Malachite Green, Leucomalachite Green, m-Cresol Purple, Cresol Red , xylenol blue, rhodamine B1 auramine,
4-p-diethylaminophenylimino naphthoquinone,
Examples include triphenylmethane-based, diphenylmethane-based, oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes represented by cyano-p-diethylaminophenylacetanilide.

Examples of coating properties improvers include alkyl ethers (e.g., ethyl cellulose, methyl cellulose), fluorine-based surfactant pillars, and nonionic surfactants (e.g., "Pluronic L-64J (manufactured by Asahi Denka), rFc-43").
0J (manufactured by 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, tetrahydrafurfuryl oleate, oligomers of acrylic acid or methacrylic acid, etc. .

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, are also used. , a modified novolac resin such as a rosin-modified novolak resin, or an 0-naphthoquinonediazide sulfonic acid ester (esterification rate of OH group: 20 to 70 mol %) of these modified novolac resins can be added.

When the above-mentioned brimer composition contains face 11, it is dispersed in an appropriate organic solvent using a known dispersion method (SGI, homogenizer, etc.) as necessary, and then filtered.

The dispersion is applied onto a support, dried, and then cured.

For photocuring, a known light source such as a mercury lamp, xenon lamp, or natural light is used, and the amount of exposure (
Usually, for example, 50mJ/crr? 5 J/crrr).

Further, the above-mentioned curing is desirably carried out at least before the coating of the photosensitive layer is completed, and more preferably immediately after coating.

In the present invention, the thickness of the primer layer is 1 mg/dm ~
500mg/drr? It is preferable that it is, more preferably 3 mg/drd to 300mg/drd
r? It is.

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 a linear or somewhat crosslinked organopolysiloxane. The organopolysiloxane usually has a molecular weight of 100,000 to several hundred thousand,
At room temperature, it is suitably cross-linked in the form of a liquid, wax, or rice cake. The organopolysiloxanes are classified into fused ring type and addition type depending on the crosslinking method.

The fused ring is crosslinked by a condensation reaction, and water, alcohol, organic acid, etc. are released by the reaction. Particularly useful condensed ring 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.

1+5i-0:F- R7 In the formula, R1 and R2 are alkyl, aryl, 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, a phenyl group, A vinyl group and a trifluoropropyl group are preferred, and a methyl group is particularly preferred.

The silicone crosslinking agents mentioned above include the so-called acetic acid-removal type, oxime-elimination type, alcohol-elimination type, deamination type, dehydration type, and those having a functional group represented by -0H (in the formula, R and R' are alkyl groups). Examples include fused ring silicone crosslinking agents such as molds. 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 or its oligomer, and reactive silane compounds having an incyanurate group.

All of these crosslinking agents are organopolysiloxane 10
It is preferable that the amount is in the range of 05 to 30 parts by weight relative to 0 parts by weight.

Examples of the condensation catalyst include dibutyltin dilaurate, dibutyltin acetate, dibutyltin maleate, and the like.

Addition type refers to an unsaturated group in the main body, such as a vinyl group (-C
It refers to something that is crosslinked by adding a hydrogen group in a crosslinking agent to H=CH2).

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 in the present invention, either or both of condensation type and addition type silicone rubber can be used.

It is also possible to use condensed and addition type organopolysiloxanes having hydroxyl groups, unsaturated groups, etc. in one organopolysiloxane.

Among the commercial products available as the silicone rubber according to the present invention, a preferable example is "KS-705FJ" manufactured by Shin-Etsu.
, rKE-41J, rKE-42J,
rKE-44”, manufactured by Toshiba Silicone (manufactured by Toshiba Silicone) rYE5
505J.

rY F 3057J, Toshi Silicone Co., Ltd. rSH
-781J, rPRX-305J, rSH
- Condensation type silicone rubber such as 237J and rK manufactured by Shin-Etsu
S-837J.

rKE-103J, rKE-106J, r
KE-1300J, Toshiba Silicone (manufactured by) rTsE-3
032J, rRTU-BJ, manufactured by Toshi Silicone (manufactured by Toshi Silicone)
Examples include addition type silicone rubber such as rsH-9555J.

Furthermore, for the purpose of improving the strength of 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 and printing stains. d-~50mg/d resistance is preferable, 5mg/d
d resistance to 30 mg/d resistance is more preferable.

Further, the photosensitive lithographic printing plate that does not require dampening water of the present invention may have a protective layer on the silicone rubber layer, and a method for providing the protective layer is to laminate a polypropylene film or the like as described in Japanese Patent Publication No. 61-614. Method and JP-A-61-27
A method of coating a high molecular weight polymer described in No. 545 is known.

As the substrate used in the present invention, any substrate can be used as long as it has the flexibility to be set in a normal lithographic printing machine and can withstand the load applied during printing, and there are no particular restrictions on the substrate including the layer structure. . For example, paper such as coated paper, metal plate such as aluminum plate, or plastic film such as polyethylene terephthalate can be cited as examples, but aluminum plate or aluminum foil and other composite materials are preferable. In terms of printability, aluminum plates are particularly preferred.

In the present invention, the photosensitive lithographic printing plate prepared as described above is imagewise exposed, and then developed with a developer to dissolve the photosensitive layer and removed together with the silicone rubber layer thereon. As a result, the brimer layer forms an image area. Upon exposure, a dampening water-less lithographic printing plate is formed.

In this case, it is preferable to dye the image area with a dye during or after development.

For such dyeing, a dyeing solution containing water as a main component and a dye as an essential component is used.

Preferred dyes include specifically the following acidic dyes and basic dyes.

Acidic dyes include nitro dyes such as Naphthol Yellow (C,1, Acid Yellow 1), monoazo dyes such as Fast Red A (CI Acid Red 88), disazo dyes such as Naphthol Blue Black (C, Acid Black 1), nitroso dyes such as Naphthol Green B (C,1, Acid Green 1), triphenylmethane dyes such as Patent Blue (C,1, Acid Blue 3), Brilliant Milling. Green B (C,1, Acid Green 9), xanthine dyes such as sulfo-rhodamina B (C,I Acid Red 52), anthraquinone dyes such as Alizarin Direct Blue A
2 G (C,r, Acid Blue 40), azine dyes such as Woolfast Blue GL (C,1
, Acid Blue 102), quinoline dyes, such as Quinoline Yellow (C,! Acid Yellow 3), etc. Preferred basic dyes include, specifically, the following.

Diphenylmethane dyes, such as Auramine O (C,I Basic Yellow 2), triphenylmethane dyes, such as Magenta (C,1, Basic Violet 14)
), methyl violet (C,I.

Basic violet 1), malachite green (C, I basic green 4), thiazole dye,
For example, Thioflavin T (C,1, Basic Yellow 1), xanthine dyes, such as Rhodamine B (C,
1, Basic Violet 10), oxazine dyes such as Neil Blue BX (C1, Basic Blue 12), thiazine dyes such as Methylene Blue B
(C,!Basic Blue 9), azine dyes such as Safranin T (C,1, Basic Red 2), azo dyes such as Bismarck Brown G (C,1, Basic Brown 1), indocyanine dyes, For example, Astrafracin FF (C, 1, Basic Red 12), etc. In the present invention, triphenylmethane dyes are particularly preferably used. These dyes are used in aqueous solutions with concentrations ranging from o,tg/ffi to 10g/ffi.
1- is preferred.

In the present invention, when dyeing is performed using these dye aqueous solutions, the concentration is 10°C to 50°C. The dyeing method is carried out by immersing the developed printing plate in a dyeing solution, or by applying or shower-sprinkling an aqueous dye solution onto the printing plate. A dyeing aid may be added to this dye aqueous solution as required.

As the dyeing aid, a water-soluble organic solvent, a surfactant, etc. are used in order to facilitate dyeing of the primer layer.

As the organic solvent, ethanol, tulfite, benzyl alcohol, etc. are preferably used, and as the surfactant, nonionic surfactants are preferred from the viewpoint of foaming properties.

As the light source used for exposure, any general-purpose light source including ultraviolet rays of 180 nm or more and visible light may be used, 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, aliphatic hydrocarbons (hexane, heptane, "Isopar E,"
H, GJ (trade name of aliphatic hydrocarbons manufactured by Esso Chemical) or gasoline, kerosene, etc.), aromatic hydrocarbons (
Toluene, xylene, etc.) or halogenated hydrocarbons (triclene, etc.) are added as necessary.

Alcohols (methanol, ethanol, β-anilinoethanol, propylene glycol, etc.) Ethers (
Methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carpitol, ethyl carpitol, butyl carpitol, dioxane, etc.) Ketones (acetone, methyl ethyl ketone, etc.) Esters (ethyl acetate, methyl cellosolve acetate, cellosolve acetate, carpitol acetate, etc.) Development This can be carried out by various known methods, such as rubbing with a developing pad containing the developer as described above, or pouring the developer onto the printing plate and then rubbing with a developing brush.

[Examples] The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

(Synthesis of Diazo Resin-1) 14.5 g of p-diazodiphenylamine sulfate was dissolved in 40.9 g of concentrated sulfuric acid under water cooling. This reaction solution contains 1, O
g of paraformaldehyde was slowly added dropwise so that the reaction temperature did not exceed 10°C. Thereafter, stirring was continued for 2 hours under water cooling. This reaction mixture was cooled with water for 500 ml (l
was added dropwise to ethanol, and the resulting precipitate was filtered. After washing with ethanol, this precipitate was dissolved in 100 mQ of pure water, and to this solution was added a cold concentrated aqueous solution in which 6.8 g of zinc chloride was dissolved. The resulting precipitate was filtered, washed with ethanol, and dissolved in 150 J of pure water. Add 8g to this liquid
A cold concentrated aqueous solution of ammonium hexafluorophosphate was added. The resulting precipitate was collected by filtration and washed with water, and then
Diazo resin-1 was obtained by drying at °C for a day and night.

The styrene-equivalent weight average molecule ffi (
Mw) was 1500, and number average molecular weight was 500.

, Shi7, L-,! , 1-El,
: 0.24mm thick, degreased 40
The following brimer layer composition was coated on a cm x 40 cm aluminum plate at 60°C using a whirler, and then heated at 100°C.
It was dried for 2 minutes and a primer layer was applied. The dry film thickness is 1
It was 30 mg/dpo.

The brimer layer composition was dispersed using a high-pressure valve homogenizer.

(Brimer layer composition) (1) Vylon UR8300: (manufactured by Toyobo) (polyester polyurethane foam)
100 parts (2) DPCA-60: (Nippon Kajigen)”-seCOCH2CH2CH2CH2CH2O←C0
CH=CH21G 60 parts (3) DETX (4) EPA 3 parts (5) KET-YELLOW402 (Yellow pigment manufactured by Dainippon Ink ■) 8 parts (6) Zinc oxide (average particle size: 0.12μ) 20 parts After coating and drying , Unicure (manufactured by USHIO INC.) -160W, '4 m7
Exposure was carried out in minutes.

On the obtained primer layer, a 2 mm x 2 nm square cellophane tape was pasted in one place to intentionally create a coating defect, and two types of primer layer coated samples were prepared, one without any coating. Prepared.

Next, the following photosensitive composition was applied on each of the above two types of primer layers and dried at 80°C for 2 minutes to a thickness of 0.
A 3 μm thick photosensitive layer was formed.

(Photosensitive composition) (1) Diazo resin - 1100 parts (2) 2-hydroxyethyl methacrylate, N-(4
-hydroxyphenyl) methacrylamide and methacrylic acid in a molar ratio of 4015515 (Mw=4.2
X 10') 100 parts (3) Dye (a) (listed in Table 1) 8 parts (4) Dye (b) (listed in Table 1) 2 parts (5) Methyl lactate 900 parts Then on the above photosensitive layer The following silicone rubber composition was applied to a thickness of 2.0 g/rrr and dried at 90°C for 10 minutes.

(Silicone rubber layer composition) (1) 100 parts of dimethylpolysiloxane (molecular weight 52,000) having hydroxyl groups at both ends (2) The following reactive silane compounds OC, 1cSi (0M e).

11] (3) Dibutyltin dilaurate 0.8 part (4
) 900 parts of Isopar E (manufactured by Esso Chemical Co., Ltd.) Next, a polypropylene film with a thickness of 6 μm was laminated on the silicone rubber layer, and a dampening water-free photosensitive lithographic printing plate sample No.
, 1 to 7 were obtained.

Each of these samples No. 001 to No. 7 was mounted on a line and flowed under a defect inspection device at a line speed of 40 m/min to examine whether any defects were found. The defect inspection device is rTO3PEcTOR-700J manufactured by Toshiba Corporation.
(using a He-Ne laser).

The same procedure was repeated 10 times for each board, and the number of jets (determined to be defective) was measured, and the results are shown in Table 1.

Next, after vacuum-adhering a positive film to the top surface of each plate, using a metal halide lamp as a light source,
J/crri exposure. In order to examine the exposure visibility at this time, the reflection density (OD) of the solid area and the clear area was measured using a reflection densitometer equipped with a visual filter, and the differences are shown in Table 1. , 2. -0 or less tea hundred.

1--1-: As is clear from Table 1, the samples of the present invention containing both Dye 11(a) and Dye (b) in the photosensitive layer had excellent exposure visible imageability and defect inspection suitability. had. On the other hand, it was found that samples containing no dye (a) had poor exposure and visible imageability, and samples containing no dye H(b) were not suitable for defect inspection.

[Effects of the Invention] As explained in detail above, the present invention provides a system using a color-forming dye that can be detected by a coating defect inspection device using a He-Ne laser and has excellent exposure visible image performance. A photosensitive lithographic printing plate that does not require dampening water can be provided.

Claims (1)

[Scope of Claims] A dampening water-free photosensitive lithographic printing plate having at least a primer layer, a photosensitive layer, and a silicone rubber layer in this order from the support side on a support, wherein the photosensitive layer comprises at least a) an acid-containing layer; 1. A photosensitive lithographic printing plate that does not require dampening water, characterized in that it contains a dye that develops color upon generation, and b) a dye whose absorbance at 633 nm is 50% or more of the absorbance at the maximum absorption wavelength.