JPH06105352B2 - Method for producing photosensitive lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a photosensitive lithographic printing plate. More specifically, it relates to a method for producing a photosensitive lithographic printing plate using a novel photopolymerizable composition in which the influence of oxygen during plate making is reduced without providing an oxygen barrier layer as another layer.

[Conventional technology]

Heretofore, attempts have been made to use a photopolymerizable composition as an image forming layer suitable for a photosensitive lithographic printing plate. For example, a basic composition consisting of an organic solvent-soluble polymer, an ethylenically unsaturated addition-polymerizable compound and a photopolymerization initiator, as described in JP-B-46-32714, is described in JP-B-49-34041. Incorporation of unsaturated double bonds into organic solvent-soluble polymers to improve curing efficiency, JP-B-48-3
8403, Japanese Patent Publication No. 53-27605 Public Relations and British Patent No. 1,388,49
Compositions using a novel photopolymerization initiator as described in the specification No. 2 are known, and some have been put to practical use. However, when any of the photosensitive compositions is used as a photosensitive layer of a lithographic printing plate, it is significantly subjected to polymerization inhibition by oxygen during imagewise exposure, so that an oxygen barrier layer made of a water-soluble resin is not provided on the surface of the photosensitive layer, It could not be used practically. However, the provision of the oxygen barrier layer made of this water-soluble resin raises the manufacturing cost and lowers the performance of the planographic printing plate. Therefore, there has been a need for a technique that is not affected by oxygen without providing an oxygen barrier layer made of a water-soluble resin. In order to reduce the influence of polymerization inhibition by oxygen, there have been attempts to add behenic acid or wax to the above-mentioned photopolymerizable composition, or to add a negative-acting diazo resin. Such an attempt is made, for example, in JP-A-49-9979.
0, JP-A-54-95687, JP-A-59-206825, JP-A-59
-53836, JP-A-59-178449, JP-A-5-196230,
And U.S. Pat. No. 4,316,949.
However, since the effect is insufficient in both cases, at the time of plate making,
There was a defect that the performance (sensitivity, printing durability) as a lithographic printing plate became unstable due to the influence of the vacuum degree of the baking frame of the exposure machine.

[Object of the Invention]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a novel photosensitive composition which ameliorates the above-mentioned drawbacks and provides high printing durability in lithographic printing plates.

[Structure of Invention]

The present inventor has added to a photopolymerizable composition containing a negative-acting diazo resin "a compound which is dissolved in a photosensitive solution but floats on the surface of a photosensitive layer during coating and drying and can form an oxygen barrier layer". It was found that by using the added composition, high printing durability can be obtained in a lithographic printing plate without being affected by oxygen substantially without providing an oxygen barrier layer as another layer. The present invention has been completed.

The present invention includes (A) an ethylenically unsaturated addition-polymerizable compound, (B) an alkali water-soluble or swellable polymer capable of forming a film, (C) a photopolymerization initiator, and (D) a negative-acting diazo resin. And (E) a higher aliphatic hydrocarbon and / or a derivative thereof, which is dissolved in the photosensitive solution but is solid at room temperature and can float on the surface of the photosensitive layer during coating and drying to form an oxygen barrier layer. However, in the method for producing a photosensitive lithographic printing plate, a photosensitive solution containing (except for polyvinyl alcohol) is applied on a support and then dried.

A photopolymerizable composition containing a negative-acting diazo resin is less susceptible to oxygen in the air than a photopolymerizable composition containing no diazo resin. It is considered that this is because the diazo resin generates nitrogen gas which is inactive against polymerization during exposure, but it is difficult to completely eliminate the influence of oxygen as described above by only adding the diazo resin. There is also known a method of forming an oxygen barrier layer by adding a so-called wax agent such as higher fatty acid to a photopolymerizable composition containing no diazo resin, but it can be said that the oxygen barrier effect is also sufficient. Absent. However, when a "compound which is dissolved in the photosensitive solution but floats on the surface of the photosensitive layer during coating and drying to form an oxygen barrier layer" is added to the photosensitive layer made of a photopolymerizable composition containing a diazo resin, It is possible to obtain an effect more than expected, and practically little influence of oxygen in the air during exposure, and it is possible to form an image with high printing durability.

The “ethylenically unsaturated addition-polymerizable compound” used in the present invention is an ethylenically unsaturated addition-polymerizable compound having a boiling point of 100 ° C. or higher at atmospheric pressure and at least one, and more preferably two or more, in at least one molecule. It is a monomer or oligomer having a group and a molecular weight of 10,000 or less. Examples of such monomers include monofunctional acrylates and methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, trimethylolethanetri (Meth) acrylate, neopentyl glycol di (meth)
Acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexanediol di (meth) acrylate trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxy) Ethyl) isocyanurate, polyfunctional alcohols such as glycerin and trimethylolethane, to which ethylene oxide and propylene oxide are added and then (meth) acrylated; JP-B-48-41708 and JP-B-50-6034; Sho 51-37
No. 193 Urethane acrylates as described in each publicity; JP-A-48-64183, JP-B-49-43191, JP-B-SHO
52-30490 Polyester acrylates described in each of the public relations; polyfunctional acrylates and methacrylates such as epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be mentioned. Furthermore, those introduced as photocurable monomers and oligomers in Japan Adhesive Association magazine Vol. 20, No. 7, pages 300 to 308 can also be used. The amount of these used is 5 to 50% by weight (hereinafter abbreviated as "%"), preferably 10%, based on all components.
~ 40%.

The "alkali water-soluble or swellable polymer capable of forming a film" used in the present invention includes -COO in the polymer.
A _{H, -PO 3 H 2, -SO} 3 H, -SO 2 NH 2, or -SO ₂ NHCO- group,
An acidic vinyl copolymer having an acid value of 50 to 200 can be mentioned. Examples of such a copolymer include Japanese Patent Publication No. 59-44615.
[Benzyl (meth) acrylate / (meth) acrylic acid / optional other addition-polymerizable vinyl monomer] copolymer as described in JP-B-54-34327
[Methacrylic acid / methyl methacrylate or ethyl / n-hexyl methacrylate]
Copolymer; Other Japanese Patent Publication No. 58-12577, Japanese Patent Publication No. 54-25957
(Meth) acrylic acid copolymers as described in JP-A No. 54-92723 and JP-A No. 54-92723; [allyl (meth) acrylate / as described in JP-A-59-53836]
(Meth) acrylic acid / another addition-polymerizable vinyl monomer as required] Copolymer; Maleic anhydride copolymer as described in JP-A-59-71048, and pentaerythritol triacrylate Examples thereof include those added by esterification.

Among these, [benzyl (meth) acrylate /
(Meth) acrylic acid / other addition-polymerizable vinyl monomers as required] copolymer, [allyl (meth) acrylate / (meth) acrylic acid / other addition-polymerizable vinyl monomers as required] copolymer Is preferred.

The composition ratio of these "ethylenically unsaturated addition-polymerizable compound" and "alkaline water-soluble or swellable polymer capable of forming a film" is preferably in the range of 0.5: 9.5 to 5: 5 by weight, more preferably in the range. Is from 1: 9 to 3: 7.

As the "photopolymerization initiator" in the present invention, US Patent No. 2,
No. 3,67,661, α-carbonyl compounds described in the respective 2,367,670 specifications, acyloin ether described in U.S. Pat.No. 2,448,828, U.S. Pat.No. 2,72
Aromatic acyloin compounds substituted with α-hydrocarbons described in U.S. Pat. No. 3,046,127.
No. 2,2,951,758, polynuclear quinone compounds, U.S. Pat.No. 3,549,367, triarylimidazole dimer / P-aminophenylketone combination, JP-A-60-105667, US Patent No.
Trihalomethyl-described in 4,239,850
S-triazine compounds, acridine and phenazine compounds described in US Pat. No. 3,751,259,
Examples thereof include oxadiazole compounds described in US Pat. No. 4,212,970. The content concentration of these photopolymerization initiator systems in the composition of the present invention is usually low, and when the content is inappropriately high, undesired results such as blocking of effective rays are produced. The amount of the photopolymerization initiator system in the present invention is 0.01 with respect to the sum of the photopolymerizable ethylenically unsaturated compound and the linear organic polymer if necessary.
% To 20% is sufficient, and more preferably 1% to 10% to obtain good results.

Further, in the photopolymerizable composition of the present invention, various organic amine compounds can be used in combination, if necessary, whereby the effect can be further enhanced. Examples of these organic amine compounds include triethanolamine, dimethylamine, diethanolaniline, P-dimethylaminobenzoic acid ethyl ester, Michler's ketone, and the like. The addition amount of the organic amine compound is preferably about 50% to 200% of the total amount of the photopolymerization initiator.

Further, the photopolymerization initiator used in the present invention may optionally contain N-phenylglycine, 2-mercaptobenzothiazole, N,
The photopolymerization initiation ability can be further enhanced by adding a hydrogen donating compound such as an N-dialkylbenzoic acid alkyl ester.

The "compound which is dissolved in the photosensitive solution but floats on the surface of the photosensitive layer at the time of coating and drying and can form an oxygen barrier layer" used in the present invention is a higher aliphatic hydrocarbon which is solid at room temperature and And / or a derivative thereof. That is, higher aliphatic hydrocarbons such as paraffin, and their hydroxy compounds, amino compounds, aldehyde compounds, carboxylic acid compounds, carboxylic acid amide compounds, nitrile compounds, carboxylic acid alkylamide compounds, arylamide compounds, alkyl ester compounds, Alternatively, ammonium or a metal salt may, for example, be mentioned. Natural wax or the like containing these may be used. Furthermore, those introduced as fats and oils on pages 1 to 149 of the second edition of the Oil and Fat Chemistry Handbook (Nippon Oil and Chemical Industry), with a melting point of 30 ° C or higher can be used. Specifically, tetracosan, nonacosan, 1-nonadecene,
Palmitic acid, margaric acid, stearic acid, nonadecanoic acid, arachidic acid, heneiconic acid, behenic acid, tricosanoic acid, lignoceric acid, cerotic acid, 14-methylpentadecanoic acid, 3-methyl-2-octylnonanoic acid,
17-methyl octadecanoic acid, 20-methyl heneicosanoic acid, lauric acid amide, tridecanoic acid amide, myristic acid amide, pentadecanoic acid amide, palmitic acid amide, heptadecanoic acid amide, stearic acid amide, oleic acid amide, elaidic acid amide, Arachic acid amide, behenic acid amide, erucic acid amide, palmitic acid N-methylamide, stearic acid N-methylamide, stearic acid anilide, stearic acid β-naphthylamide, arachidic acid anilide, 1-docosanol, 1-tocosanol, 1-penta Triacontanol, nonadecane 1-oil, eicosan 1-ol, mannitane, erythritol, 13-oxytridecylamine, laurinaldehyde, stearaldehyde, myristate 2-alkylbenzimidazole Cerotic acid methyl ester,
Examples thereof include triacontyl stearate, 1,13-tridecamethylene dicarboxylic acid, 15-oxypentadecanoic acid, myristic acid glycerin ester, ethyl stearate, stearylamine, n-dodecyl stearate, and sodium stearate. In the present invention, those having a melting point of 60 ° C. or higher are preferable. These compounds may be used alone or as a mixture of several kinds. The amount added is 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the total composition.

As the negative-working diazo resin used in the present invention, those substantially insoluble in water and soluble in an organic solvent are suitable. Examples of such diazo resins include 4-diazo-diphenylamine, 1-diazo-4-N, N-dimethylaminobenzene, 1-diazo-4-N, N-diethylaminobenzene,
1-diazo-4-N-ethyl-N-hydroxyethylaminobenzene, 1-diazo-4-N-methyl-N-hydroxyethylaminobenzene, 1-diazo-2,5-diethoxy-4-benzoylaminobenzene, 1-diazo-
4-N-benzylaminobenzene, 1-diazo-4-N,
N-dimethylaminobenzene, 1-diazo-4-morpholinobenzene, 1-diazo-2,5-dimethoxy-4-
p-Tolylmercaptobenzene, 1-diazo-2-ethoxy-4-N, N-dimethylaminobenzene, p-diazo-dimethylaniline, 1-diazo-2,5-dibutoxy-
4-morpholinobenzene, 1-diazo-2,5-diethoxy-4-morpholinobenzene, 1-diazo-2,5-
Dimethoxy-4-morpholinobenzene, 1-diazo-
2,5-Diethoxy-4-morpholinobenzene, 1-diazo-2,5-diethoxy-4-p-tolylmercaptobenzene, 1-diazo-3-ethoxy-4-N-methyl-
N-benzylaminobenzene, 1-diazo-3-chloro-4-N, N-diethylaminobenzene, 1-diazo-3
-Methyl-4-pyrrolidinobenzene, 1-diazo-2-
Chloro-4-N, N-dimethylamino-5-methoxybenzene, 1-diazo-3-methoxy-4-pyrrolidinobenzene, 3-methoxy-4-diazodiphenylamine, 3
-Diazomonomers such as -ethoxy-4-diazophenylamine, 3- (n-propoxy) -4-diazodiphenylamine, 3- (isopropoxy) -4-diazodiphenylamine, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, A condensing agent such as isobutyraldehyde or benzaldehyde in a molar ratio of 1: 1 to 1: 0.5, preferably 1: 0.8 to 1: 0.6, respectively.
And a reaction product of an anion with a condensate obtained by condensing by a conventional method. As the anion, tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitroortho-toluenesulfonic acid, 5
-Sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid , Dodecylbenzene sulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-
4-hydroxy-5-benzoyl-benzenesulfonic acid, paratoluenesulfonic acid, etc. can be mentioned. Also suitable are the diazo resins described in US Pat. No. 3867147. Among these, especially hexafluorophosphoric acid,
Alkyl aromatic sulfonic acids such as triisopropyl naphthalene sulfonic acid and 2,5-dimethylbenzene sulfonic acid are preferred.

The amount of these diazo resins added to the total composition is 1 to 30.
%, More preferably 3 to 15% by weight.

In addition to the above, it is preferable to add a thermal polymerization inhibitor to the photosensitive layer, for example, hydroquinone, p-tomexiphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4 , 4′−
Thiobis (3-methyl-6-t-butylphenol),
2,2'-methylenebis (4-methyl-6-t-butylphenol), 2-mercaptobenzimidazole, etc. are useful, and in some cases, a pH indicator as a dye or pigment or a baking agent for the purpose of coloring the photosensitive layer. Etc. can also be added.

Further, as a stabilizer of diazo resin, phosphoric acid, phosphorous acid,
Tartaric acid, citric acid, malic acid, dipicolinic acid, polynuclear aromatic sulfonic acid and its salt, sulfosalicylic acid and the like can be added if necessary.

Further, as a technique for improving vacuum adhesion during exposure and reducing oxygen on the surface of the photosensitive layer, JP-A-55-124147 and JP-A-5-124147 have been proposed.
A matting agent as described in 5-32086 may be added to the photosensitive layer.

Furthermore, it improves the coating surface quality and / or higher aliphatic hydrocarbons and / or
Alternatively, a fluorine-based surfactant or the like may be added in order to easily float the derivative on the surface of the photosensitive layer.

The photosensitive composition of the present invention comprises, for example, 2-methoxyethanol, 2-methoxyethyl acetate, propylene glycol monomethyl ether, 3-methoxypropanol, 3-methoxypropyl acetate, methyl ethyl ketone, ethylene dichloride, and a suitable solvent such as water. It is possible to coat the support alone or dissolve it in a mixed solvent in which these are appropriately combined. It is preferable to use an ultrasonic disperser at the time of dissolution because dissolution is accelerated. The coating amount in the range of about 0.1 g / m ² ~ about 10 g / m ² in weight after drying are suitable, more preferably from 0.5 to 5 g / m ^2.

A suitable support for coating the photosensitive composition of the present invention is
It is a dimensionally stable plate. Such dimensionally stable plate-like materials include those conventionally used as a support for printing plates, and they can be preferably used in the present invention. Examples of the support include paper, paper laminated with plastics (for example, polyethylene, polypropylene, polystyrene, etc.), aluminum (including aluminum alloys), metal plates such as zinc and copper, cellulose diacetate, and triacetate. Films of plastics such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal and the like, or the above-mentioned metal laminated or vapor deposited paper or Includes plastic film, etc.
Of these supports, the aluminum plate is preferred because it is dimensionally remarkably stable and inexpensive. Furthermore,
A composite sheet in which an aluminum sheet is bonded onto a polyethylene terephthalate film as described in JP-B-48-18327 is also preferable.

Further, in the case of a support having a surface of metal, particularly aluminum, it is subjected to surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or anodization treatment. Is preferred. Further, as described in U.S. Pat.No. 2,714,066, an aluminum plate which has been grained and then immersed in an aqueous solution of sodium silicate, and anodized aluminum plate as described in JP-B-47-5125. After that, a product obtained by immersion treatment in an aqueous solution of an alkali metal silicate is also suitably used. The anodizing treatment, for example,
Inorganic acids such as phosphoric acid, chromic acid, sulfuric acid, boric acid, etc., or organic acids such as oxalic acid, sulfamic acid or the like, or an aqueous solution or a non-aqueous solution of these salts, or an aluminum plate as an anode in an electrolytic solution combining two or more kinds. It is carried out by passing an electric current.

Further, silicate electrodeposition as described in US Pat. No. 3,658,662 is also effective.

Furthermore, JP-B-46-27481, JP-A-52-58602,
A surface treatment in which a support subjected to electrolytic graining as disclosed in JP-A-52-39503 is combined with the anodizing treatment and the sodium silicate treatment is also useful.

Further, as disclosed in JP-A-56-28893, a brush grain, an electrolytic grain, an anodizing treatment, and a sodium silicate treatment in this order are also preferable. Furthermore, after these treatments, a water-soluble resin such as polyvinyl phosphonic acid, a polymer or copolymer having a sulfonic acid group in its side chain, or a polyacrylic acid undercoat is also suitable.

These hydrophilization treatments, in addition to the treatment for making the surface of the support hydrophilic, prevent harmful reaction with the photosensitive composition provided thereon, and further improve the adhesion to the photosensitive layer. It is provided to improve the

On the layer of the photosensitive composition provided on the support, JP-A-SHO 50
-125805, JP-A-55-30619, JP-A-51-111102, JP-B-61-28986, JP-A-59-211044, JP-A-55-12974
In order to more completely prevent the matting layer as described in each specification, the layer for preventing tackiness of the photosensitive layer at high temperature, and the polymerization inhibiting action by oxygen in the air, for example, polyvinyl alcohol A protective layer made of a polymer having excellent oxygen barrier properties such as acidic celluloses may be provided. For the coating method of such a protective layer, for example, U.S. Pat.
It is described in detail in Japanese Patent Publication No. 458,311 and Japanese Patent Publication No. 55-49729.

The photosensitive plate provided with the photosensitive composition of the present invention on a support is image-exposed using a light source rich in ultraviolet rays such as a metal halide lamp and a high-pressure mercury lamp, and processed with a developing solution to unexpose the photosensitive layer. A lithographic printing plate can be obtained by removing a part and finally applying a gum solution. Preferred as the developing solution is an alkaline aqueous solution containing a small amount of an organic solvent such as benzyl alcohol, 2-phenoxyethanol and 2-butoxyethanol, and is described in, for example, U.S. Pat. Nos. 3,475,171 and 3,615,480. I can list things. Further, JP-A-50-26601,
The developers described in JP-B-56-39464, JP-B-56-42860, and JP-A-58-54341 are also excellent as developers for photosensitive printing plates using the photosensitive composition of the present invention. ing.

[Examples] Hereinafter, further details will be described based on Examples. In addition,% shows weight%.

Example 1 A substrate was prepared by the method disclosed in JP-A-56-28893. That is, an aluminum plate having a thickness of 0.30 mm was grained on its surface using a nylon brush and an aqueous suspension of 400 mesh pumice, and then washed thoroughly with water. It was immersed in 10% sodium hydroxide at 70 ° C. for 60 seconds for etching, washed with running water, neutralized with 20% HNO ₃ and washed with water. This was subjected to electrolytic surface-roughening treatment in an aqueous 1% nitric acid solution at an anodic electricity of 160 clones / dm ² using a sinusoidal alternating current under the condition of V _A = 12.7V. When the surface roughness was measured, it was 0.6 μ (Ra display). Continued 30% H ₂ S
After soaking in O ₄ aqueous solution and desmutting treatment at 55 ° C for 2 minutes, anodizing treatment in 20% H ₂ SO ₄ aqueous solution for 2 minutes at a current density of 2 A / dm ^{2 to} a thickness of 2.7 g / m ^2. did. Then, it was immersed in a 2.5% aqueous solution of sodium silicate at 70 ° C for 1 minute, washed with water, and dried.

The following photosensitive solution (1) was prepared.

Photosensitive solution (1) -Trimethylolpropane triacrylate 20g-Poly (acrylic methacrylate / methacrylic acid) copolymer Copolymer with molar ratio 80/20 50g-2,4-Trichloromethyl- (4'-methoxynaphthyl) s-triazine 2g-Hexafluorophosphate 2g of a condensate of p-diazodiphenylamine and formaldehyde-Behenamide 1g-Propylene glycol monomethyl ether 1500g-F-177 (Dainippon Ink and Chemicals Fluorosurfactant)
1.5 g of this photosensitive solution (1) was filtered and then coated on the above substrate by a spin coater so that the weight after drying was 2.0 g / m ² . Drying was carried out at 80 ° C. for 2 minutes, and this was designated as sample A.

As a comparative example, a photosensitive solution containing no behenic acid amide was prepared from the photosensitive solution (1), and similarly coated and dried to obtain a sample B. Further, a photosensitive solution containing no hexafluorophosphate of a condensate of p-diazodiphenylamine and formaldehyde was prepared from the photosensitive solution (1), coated similarly, and dried to obtain a sample C.

To compare the effect of oxygen on these plates, a PS step guide made by Fuji Photo Film Co., Ltd. (gray scale in which the transmission density changes discontinuously at ΔD = 0.15) was placed on the sample It was exposed with a Nuark printer (light source; 2KW metal halide lamp). At this time, it was exposed by changing the vacuum evacuation of the printer's baking frame, treated with the negative developer DN-3C for PS plate manufactured by Fuji Photo Film Co., Ltd. diluted 1: 1 with water, and unexposed. Parts were removed.

As shown in Table 1, the number of steps of the step guide on the plate after development was not affected by the degree of vacuum of sample A, and the sensitivity was high. Sample B was affected by the degree of vacuum and had low sensitivity. Since the sample C does not contain the diazo resin, the amount of light to the photopolymerization initiator is large, and when the evacuation is sufficient, the sensitivity is higher than that of the sample A, but the influence of the degree of vacuum is large.

When these samples were printed with the Heidelberg KOR-D printing machine, the results shown in Table 2 were obtained, and sample A was not affected by the degree of vacuum much more than samples B and C and had high printing durability. Met.

Further, after the sample A was left under the condition of 45 ° C. and 75% RH for 3 days, the same test was conducted, and more than 100,000 printed materials were obtained in the same manner.

Examples 2 to 12 The following photosensitive solution (2) was used in place of the photosensitive solution of Example 1, and a plate obtained by applying and drying in the same manner was used as sample D, and the behenic acid of the photosensitive solution (2) was shown. The plates obtained from the sensitizing solution in which the compound of 3 was replaced were designated as samples E to N. As a comparative example, the plate excluding behenic acid was set to O. A sample in which an oxygen barrier layer made of polyvinyl alcohol was provided on the sample D at 2.0 g / cm ² was designated as P.

The influence of the degree of vacuum on the sensitivity of these samples D to P was examined in the same manner as in Example 1. As shown in Table 3, in Samples D to N, the influence of the degree of vacuum was smaller than that in Sample O, and the sensitivity was high, and the same sensitivity as Sample P provided with a complete oxygen barrier layer was obtained.

Further, when the influence of the degree of vacuum on the printing durability was examined in the same manner as in Example 1, 100,000 or more printed materials were obtained in each of Samples D to N and P, but 5 in the sample with O vacuuming. In the case of 10,000 samples with insufficient vacuum drawing, 10,000 sheets resulted in printing failure.

Examples 13 to 18 In place of the photosensitive solution of Example 1, the following photosensitive solution (3) was applied and dried in the same manner to form a plate, which was designated as sample Q.

Photosensitive solution (3) -Tri (acryloyloxyethyl) isocyanurate 30g-Poly (benzyl methacrylate / methacrylic acid) copolymer 50g Copolymer with molar ratio of 75/25 2-Trichloromethyl-5- (pn-butoxystyryl) ) -1,3,4-Oxadiazole 2g ・ Hexafluorophosphate 3g of condensate of p-diazodiphenylamine and formaldehyde ・ Behenamide 1.0g ・ Behenic acid 1.0g ・ Propylene glycol monomethyl ether 1500g ・ F177 [Dainippon Ink and Co., Fluorosurfactant]
1.5 g Further, the plates obtained from the photosensitizing solution (3) in which behenic acid amide and behenic acid were changed to the compounds in Table 4 were designated as samples R to V.

As a comparative example, a plate obtained from a photosensitive solution obtained by removing behenic acid amide and behenic acid from photosensitive solution (3) was used as sample W.

The influence of the degree of vacuum on the sensitivity of these samples Q to W was examined in the same manner as in Example 1. As shown in Table 4, Samples Q to V were less affected by the degree of vacuum and more sensitive than Sample W.

When the effect of the degree of vacuum on printing durability was examined in the same manner as in Example 1, 100,000 or more printed materials were obtained in each of Samples Q to V, but 30,000 sheets were printed in the sample with W vacuuming. In the case of the sample in which the vacuuming was insufficient, printing failure occurred after printing 5,000 sheets.

〔The invention's effect〕

Since the photosensitive layer of the photosensitive lithographic printing plate produced by the method of the present invention is less susceptible to oxygen during exposure, it is possible to form an image with high printing durability. Therefore, the printing plate obtained from the photosensitive printing plate according to the present invention has excellent printing durability.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noriaki Watanabe 4000 Kawasakiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture Fujisha Shin Film Co., Ltd. (56) References JP 47-13085 (JP, A) JP 58-2847 (JP, A) JP 62-195665 (JP, A)

Claims (1)

[Claims] 1. An (A) ethylenically unsaturated addition-polymerizable compound, (B) an alkali water-soluble or swellable polymer capable of forming a film, (C) a photopolymerization initiator, and (D) a negative-acting diazo. Higher aliphatic hydrocarbons and / or derivatives thereof, which are dissolved in the resin and (E) the photosensitive liquid, but can float on the surface of the photosensitive layer during coating and drying to form an oxygen barrier layer, which are solid at room temperature. A method for producing a photosensitive lithographic printing plate, which comprises applying a photosensitive solution containing (excluding polyvinyl alcohol) onto a support and further drying.