JPH0743501B2 - Positive photosensitive lithographic printing plate - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a positive-working photosensitive lithographic printing plate provided with a positive-working photosensitive composition, and in particular, a positive-working photosensitive composition having wide development latitude and high sensitivity. And a positive photosensitive lithographic printing plate provided with. More specifically, by adding a specific compound to a positive-type photosensitive composition which has been made highly sensitive by a conventionally known method, a positive-type photosensitive composition having a wide development latitude without lowering the sensitivity is provided. Positive type photosensitive lithographic printing plate.

[Prior Art] A photosensitive composition containing an o-quinonediazide compound has been industrially used as a very excellent positive photosensitive composition for producing a lithographic printing plate and as a photoresist.
Heretofore, various proposals have been made for a method of enhancing the photosensitivity of the o-quinonediazide-based positive-type photosensitive composition, but no satisfactory method has been obtained. For example, if the amount of the o-quinonediazide compound is decreased, the sensitivity naturally increases, but the development tolerance (30%
Change in the number of solid gray scale steps with a density difference of 0.15 between second development and 5 minute development. The smaller the change, the wider the development tolerance. same as below. ) Becomes narrower, which is not practical. Further, a system in which a binder resin having a high solubility in an alkaline aqueous solution is combined with an o-quinonediazide compound has a drawback that the apparent sensitivity is increased, but the development acceptability is narrowed as in the case described above. .

Further, a technique has been proposed in which a non-photosensitive compound (sensitizer) is added to a photosensitive composition containing an o-quinonediazide compound to increase sensitivity, but none of them has obtained sufficient effects. At the present time, it has various drawbacks. For example, as described in U.S. Pat.No. 3,661,582, sensitivity can be increased by the addition of certain heterocyclic compounds such as 2-azacyclononane-2-one, indole, quinazoline and tetrazole, Also in this case, as in the case described above, the development tolerance was extremely narrow.

Further, JP-B-46-42449 describes various additives for increasing photographic sensitivity, such as triphenylmethane dye, benzaldehyde-m-tolylhydrazone, halogenated hydrocarbon and azo dye. , These compounds do not have a significant effect on the enhancement of sensitivity. For the same purpose, addition of o-benzoic acid sulfimide, hydantoin and its derivative, and thiohydantoin and its derivative have been proposed (see JP-A-50-36203). Further, additives for cyclic acid anhydrides have been proposed for the same purpose (see Japanese Patent Laid-Open No. 52-80022). However, even in these cases, there is a drawback that the developing tolerance at the time of development becomes narrow when the addition amount is such that the increase in sensitivity is recognized. Further, a high-sensitivity copying material containing polyhydroxybenzophenone has been proposed (see JP-A-52-54503), but the compound is added to improve the adhesion to a support. Although the sensitivity is slightly increased as a side effect, a remarkable effect of increasing the sensitivity cannot be expected. Further, addition of a condensation product of hydroxybenzophenone and formaldehyde has been proposed for the purpose of increasing sensitivity (see JP-A-55-73045), but in this case, JP-A-52-54503 has been proposed. As in the case of the compounds in the publication, a considerable amount of addition was necessary for a clear increase in sensitivity to be recognized, and a reduction in development acceptability and chemical resistance was unavoidable. Further, JP-A-57-118237 and JP-A-57-118238 describe adding compounds represented by the following general formulas [A] and [B], respectively. In these cases, However, in the case where a clear increase in sensitivity was recognized, there was a drawback in that development acceptability was extremely lowered.

General formula [A] General formula [B] (In the above general formula [A], R is a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, a substituted aryl group, a cycloalkyl group or an alkali metal, and in the general formula [B], R ₁ , R ₂ ,
R ₃ represents a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a substituted aryl group, an acyl group, a halogen group, a nitro group or a hydrogen group. Further, in JP-A-59-121044, development is carried out by incorporating at least one selected from the group consisting of an amphoteric surfactant and an organoboron-based surfactant in a positive type photosensitive composition having a high sensitivity. Although a method of widening the acceptability has been shown, there are some kinds of these surfactants which are insufficient in effect in addition to having a small kind, and on the contrary, those which deteriorate the development acceptability. It had a drawback of deteriorating the print-out property.

[Object of the Invention]

The object of the present invention is to obtain a positive photosensitive composition comprising an o-quinonediazide compound used in the production of a positive photosensitive lithographic printing plate, which is obtained by increasing the sensitivity by a known method as described above. -To provide a positive photosensitive composition having a wide development latitude without deteriorating the print-out property.

[Structure of Invention]

The present inventors have found that the above object can be achieved by incorporating a nonionic surfactant into the positive photosensitive composition.

The "nonionic surfactant" used in the present invention does not include a so-called fluorine-based surfactant having a perfluoroalkyl group.

Therefore, the present invention is specifically a positive photosensitive lithographic printing plate comprising a support and a positive photosensitive composition containing an o-quinonediazide compound, wherein the positive photosensitive composition is a nonionic composition. The surfactant is contained, and the nonionic surfactant is polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyethylene. Those selected from the group consisting of glycol fatty acid ester, fatty acid monoglyceride, sorbitan fatty acid ester, pentaerythril fatty acid ester, propylene glycol fatty acid ester, polyglycerin fatty acid ester, and mixtures of two or more thereof. A positive photosensitive lithographic printing plate, characterized in that.

The positive photosensitive composition used in the present invention includes those conventionally known as a positive photosensitive composition containing an o-quinonediazide compound. Particularly, a compound comprising an o-quinonediazide compound and a phenolic resin is preferable.

The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group,
It increases alkali solubility by active irradiation, and compounds having extremely various structures can be used. Such o
-Regarding quinonediazide compounds, J. Coser, "Light-Sensitive Systems" (John Wiley & So
ns, Inc.) pp. 339-352, which may be used in the present invention. Particularly preferred is a sulfonic acid ester or sulfonamide of o-quinonediazide by reacting with various aromatic polyhydroxy compounds or aromatic amino compounds.

Among the o-quinonediazide compounds used in the present invention,
An ester of benzoquinone (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 is disclosed. Most preferred. Other suitable o-quinonediazide compounds include benzoquinone- (1,2) -diazidesulfonic acid chloride or naphthoquinone- (1,2) described in U.S. Pat.Nos. 3,046,120 and 3,188,210.
There are esters of diazide sulfonic acid chloride with phenol-formaldehyde resins.

As other useful o-quinonediazide compounds, those reported and known in numerous patents can be used. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, and JP-A-49-38701.
48-13354, Japanese Examined Sho 41-11222, Do 45-9610, Do 4
9-17481, U.S. Pat.Nos. 2,797,213 and 3,454,40
No. 0, No. 3,544,323, No. 3,573,917, No. 3,674,4
No. 95, No. 3,785,825, British Patent No. 1,227,602, No.
1,251,345, 1,267,005, 1,329,888, 1,330,932, and German Patent No. 854,890 may be mentioned.

Further, such an o-quinonediazide compound can be used alone in the positive photosensitive composition according to the present invention, but is preferably used by mixing with a binder. Suitable binders include novolak resins that are soluble in aqueous alkali solutions. Typical examples of such novolac resin include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde resin, p-tert-butylphenol-formaldehyde resin, and phenol-modified xylene resin.

Further, a polyvinyl compound having a phenolic hydroxyl group, for example, a polyhydroxystyrene polymer and its copolymer, a halogenated polyhydroxystyrene polymer and a copolymer can also be mentioned.

The amount of o-quinonediazide compound in the total composition is 10 to 50% by weight, more preferably 20 to 40% by weight. And the amount of phenolic resin is 45-80% by weight of the total composition.
And preferably 50 to 70% by weight.

The positive-type photosensitive composition used in the present invention can be increased in sensitivity by a conventionally known method, and further, the sensitivity can be increased to a region where development tolerance is narrow and cannot be used. As a specific method for increasing the sensitivity, a decrease in the o-quinonediazide substitution ratio of the o-quinonediazide compound,
Decrease in molecular weight of o-quinonediazide compound, decrease in amount of o-quinonediazide compound used, binder having high solubility in alkaline aqueous solution (for example, decrease in molecular weight of binder, increase in phenol or m-cresol content, carboxylic acid group or carbenoic anhydride group content) Incorporation of a binder) and addition of various compounds for increasing sensitivity, for example, certain heterocyclic compounds (for example, 2-azacyclononane-2-one, indole, quinazoline and tetrazole: US Pat. No. 3,661,592) Reference),
Sulfimide o-benzoate, hydantoin and its derivatives, thiohydantoin and its derivatives (Japanese Patent Laid-Open No. 36203/1975)
JP-A-52-54503, cyclic acid anhydride (see JP-A-52-80022), and polyhydroxybenzophenone (JP-A-52-54503).
No.), a condensation product of hydroxybenzophenone and formaldehyde (see JP-A-55-73045),
The above general formula [A] (see JP-A-57-118237), general formula [B] (see JP-A-57-118237), bisphenol A (see Japanese Patent Application No. 59-6049), etc. The sensitivity can be increased by combining two or more of these known techniques. When an additive for increasing the sensitivity is used, the addition amount is 0.5 to 3 in the total composition.
0% by weight is suitable, more preferably 1 to 20% by weight, and two or more kinds can be used in combination.

A nonionic surfactant is added to the positive photosensitive composition used in the present invention.

The nonionic surfactant used in the present invention is (1) polyoxyethylene alkyl ether (2) polyoxyethylene alkylphenyl ether (3) polyoxyethylene polyoxypropylene block polymer (4) polyoxyethylene sorbitan resin acid ester ( 5) Polyoxyethylene glycerin fatty acid ester (6) Polyethylene glycol fatty acid ester (7) Polyoxyethylene fatty acid amine (8) Fatty acid monoglyceride (9) Sorbitan fatty acid ester (10) Pentaerythritol fatty acid ester (11) Propylene glycol fatty acid ester (12) ) Polyglycerin fatty acid ester (13) Fatty acid alkanolamide (14) Amine oxide, among which (1) (2) (4) (5) (6)
(8) (9) (10) (11) (12) (13) are preferred,
(1) (2) (4) (5) (8) (9) are more preferable.

Specific examples of the polyoxyethylene alkyl ether represented by the general formula RO (CH ₂ CH ₂ O) _n H include the following.

General formula Specific examples of the polyoxyethylene alkylphenyl ether represented by are the following.

Specific examples of the polyoxyethylene polyoxypropylene block polymer represented by the general formula HO (CH ₂ CH ₂ O) _n (C ₃ H ₆ O) _m (CH ₂ CH ₂ O) _n H include the following. To be

As the polyoxyethylene sorbitan fatty acid ester, for example, the general formula Specific examples of what is represented by are as follows.

As the polyoxyethylene glycerin fatty acid ester, for example, a general formula Specific examples of what is represented by are as follows.

Formula _{RCOO (CH 2 CH 2 O)} n A: are the following specific examples of the polyethylene glycol fatty acid ester represented by (A H or -OCR).

General formula Specific examples of the polyoxyethylene fatty acid amine represented by are as follows.

Fatty acid monoglycerides, for example The following are specific examples of what is represented by.

Sorbitan fatty acid ester The following are specific examples of what is represented by.

Pentaerythritol fatty acid ester for example The following are specific examples of what is represented by.

General formula The following are specific examples of the propylene glycol fatty acid ester represented by.

Polyglycerin fatty acid ester (RCOO) qA, A: Polyglycerin residue q: 1 to 4 And so on.

Fatty acid alkanolamides for example Specific examples include the following.

Amine oxide As specifically And so on.

The addition amount of the nonionic surfactant used in the present invention is appropriately 0.1 to 20% by weight based on the total weight of the photosensitive composition, and two or more kinds can be used in combination.

The composition of the present invention may further contain an amphoteric surfactant or an organic boron surfactant described in JP-A-59-121044.

Further, in the positive photosensitive composition of the present invention, a filler,
Dyes, dyes, pigments, photodegradable acid generators such as 1,2-naphthoquinone- (2) -4-sulfonic acid chloride, fluorosurfactants for improving coatability, and other conventional additives and Auxiliary agents can be included. Although these additives vary depending on their type, the amount added is generally 0.01 to 20% by weight, preferably 0.05 to 10% by weight based on the total composition.
Weight percent is suitable. The dyes preferably used in the present invention include basic dyes and oil-soluble dyes.
Specifically, Victoria Pure Blue BOH, Victoria Blue BR, Methyl Violet, Eisen Malachite Green (above, Hodogaya Chemical Co., Ltd.),
Basic dyes such as Patent Pure Blue VX, Rhodamine B, Methylene Brae (above, Sumitomo Chemical Co., Ltd.),
And Sudan Blue II, Victoria Blue F4
Oil-soluble dyes such as R (above, manufactured by BASF), Oil-Blue # 603, Oil Blue-BOS, Oil-Blue IIN (above, manufactured by Orient Chemical Industry) can be mentioned. 1,2-naphthoquinone- (2)-as photodegradable acid generator
In addition to 4-sulfonic acid chloride, trihalomethyl-2-pyrone and trihalomethyltriazine described in JP-A-53-36223 and various o-types described in JP-A-55-62444.
A naphthoquinonediazide compound, a 2-trihalomethyl-5-aryl-1,3,4-oxadiazole compound described in JP-A-55-77742 can be added. Preferred examples of the fluorosurfactant for improving the coating property include (i) a fluorinated compound having 3 to 20 carbon atoms and containing 40% by weight or more of fluorine, and having at least three terminal portions with fluorination. Copolymer of (ii) poly (oxyalkylene) acrylate or poly (oxyalkylene) methacrylate with an acrylate containing a fluoroaliphatic group having a selected carbon atom (hereinafter referred to as Rf group) or a methacrylate containing an Rf group A fluorosurfactant in which the Rf group-containing acrylate or Rf group-containing methacrylate monomer unit is 10 to 70% by weight based on the weight of the copolymer can be mentioned.

The photosensitive composition as described above is applied and dried on a support suitable for a lithographic printing plate such as an aluminum plate, a zinc plate, a steel plate, or a chrome-plated iron plate, and then the positive photosensitive lithographic plate of the invention is used. A printing plate is obtained. At this time, the support may be surface-treated electrically, mechanically or chemically in order to improve the adhesion.

The photosensitive composition according to the present invention is used by dissolving it in various organic solvents at the time of coating. Examples of the solvent used here include methyl alcohol, ethyl alcohol, and n.
-Propyl alcohol, iso-propyl alcohol, secondary butyl alcohol, acetone, methyl ethyl ketone,
Benzene, cyclohexane, methyl acetate, ethyl acetate,
Isopropyl acetate, ethyl formate, propyl formate, isobutyl formate, methyl propionate, ethyl propionate,
Chloroform, carbon tetrachloride, methylene dichloride, ethylene dichloride, 1,1,1-trichloroethane, isopropyl ether, tetrahydrofuran, tetrahydropyran, ethylene glycol dimethyl ether, n-butyl alcohol, iso-butyl alcohol, methyl n-
Propyl ketone, methyl n-butyl ketone, methyl iso-butyl ketone, diethyl ketone, toluene, m-xylene, p-xylene, n-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-butyl formate, Amyl formate, methyl butyrate, ethyl butyrate, monochlorobenzene, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl n-amyl ketone, methyl n-hexyl Ketone, ethyl n-butyl ketone, di n-propyl ketone, diiso-butyl ketone, acetylacetone,
Cyclohexanone, methylcyclohexanone, diacetone alcohol, acetylacetone, o-xylene, n-amyl acetate, iso-amyl acetate, methyl iso-amyl acetate, methoxybutyl acetate, dihexyl acetate, 2-acetic acid
Ethyl butyl, cyclohexyl acetate, methyl acetoacetate, n-butyl propionate, n-butyl butyrate, iso-amyl butyrate, n-butyl ether, 2-ethoxytetrahydropyran, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol mono Isopropyl ether,
Ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol dibutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol isoamyl ether, ethylene glycol monohexyl ether, ethylene glycol monoacetate, ethylene glycol diacetate, methoxymethoxyethanol, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol monoisopropyl ether, propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol Monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol diethyl ether, hexylene glycol, 3-methoxy-3 -Methoxybutanol, N, N-dimethylamide, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, ethylene glycol monophenyl ether, ethylene glycol monophenyl ether acetate, ethylene glycol benzyl ether, ethylene glycol butyric acid monoester, ethylene glycol propion Acid diester, ethylene glycol butyrate diester, diet Glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol dibutyl ether, diethylene glycol monoacetate, dipropylene glycol monoethyl ether acetate, triethylene glycol monomethyl ether, triethylene Glycol monoethyl ether, triethylene glycol monobutyl ether, triethylene glycol dimethyl ether, triglycol dichloride, 1-butoxyethoxy propanol, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, etc. There are, may be used singly or in combination. The solid content concentration in the coating liquid component is preferably in the range of 1 to 50% by weight. In addition, the coating amount varies depending on the application, but generally 0.5 to 4.0 as solid content.
g / m ² is suitable. Further, as a coating method, any conventionally known coating technique can be used.

In the use of the light-sensitive material thus obtained, a conventionally-used method can be applied, for example, a transparent original image having a line image, a halftone image, etc. is exposed in close contact with the photosensitive surface,
Then by developing this with an alkaline aqueous solution,
A positive relief image is obtained with respect to the original image. As a light source suitable for exposure, a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp or the like is used, and as an alkaline aqueous solution used for development, sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide is used. , Aqueous solutions of sodium phosphate tribasic, sodium phosphate dibasic, sodium carbonate, potassium carbonate and the like. The concentration of the alkaline aqueous solution at this time varies depending on the type of the photosensitive composition and the alkali, but is generally in the range of 0.1 to 10% by weight, and the acid-alkaline aqueous solution may contain a surfactant, alcohol, etc., if necessary. It is also possible to add such an organic solvent.

[Advantages of the Invention] Since the positive-working photosensitive positive-working lithographic printing plate according to the present invention has a wide development latitude, the sensitivity can be further increased by a strong developing solution such as a strong alkaline solution, a high-concentration developing solution, or high-temperature development.

The positive-working photosensitive lithographic printing plate according to the present invention has a high sensitivity and a wide development allowance as compared with the conventional positive-working photosensitive composition, and thus the exposure time can be shortened and the workability is improved. To do.

As described above, the positive photosensitive lithographic printing plate according to the present invention is extremely useful.

〔Example〕

The present invention will be illustrated by the following examples, but the embodiments of the present invention are not limited thereby.

In addition, all "%" in the following examples are% by weight unless otherwise specified.

Examples 1 to 6 and Comparative Example a An aluminum plate (material 1050) having a thickness of 0.3 mm was washed with trichlene to degrease it, and then the surface thereof was grained using a nylon brush and a 400-mesh Pumisu water suspension, and the surface was well watered. Washed with. This plate was immersed in a 25% sodium hydroxide aqueous solution at 45 ° C. for 9 seconds for etching, washed with water, and further immersed in 20% nitric acid for 20 seconds and washed with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, this plate was provided with a DC anodic oxide coating of 3 g / m ² at a current density of 15 A / dm ² using 7% sulfuric acid as an electrolytic solution, and then washed with water and dried. Next, the following photosensitive solutions Examples 1 to 6 and Comparative Example a were applied to this aluminum plate and dried at 100 ° C. for 2 minutes to obtain positive type photosensitive lithographic printing plates 1 to 6 and a. The applied amount after drying is 2.4-
It was 2.5 g / m ² .

Note US Patent No. 3,635,709 described in Example 1 Note US Patent No. 4,123,279 described in each of these photosensitive lithographic printing plates from a distance of 70 cm with a 1.5 KW metal halide lamp. After exposure, with an 8 times dilution of DP-4 (trade name: Fuji Photo Film Co., Ltd.),
Automatic development (800 U: by Fuji Photo Film Co., Ltd. automatic developing machine) was performed at 25 ° C. for 40 seconds. The appropriate exposure time at this time was set to a point where 5 steps were completely clear in gray scale (manufactured by Fuji Photo Film Co., Ltd.) with a density difference of 0.15, and this was taken as the sensitivity of the photosensitive printing plate.

Further, the change value of the gray scale solid step number in 30 second development and the solid step number in 5 minute development (hereinafter referred to as development acceptability) was obtained by vat development at 25 ° C. with 8 times diluted solution of DP-4.

Table 1 shows the results of the sensitivity (exposure time) and development acceptability of these positive photosensitive printing plates.

As can be seen from Table 1, in comparison with Comparative Example a in which the nonionic surfactant was not added, in Examples 1 to 6 in which the nonionic surfactant was added, the sensitivity (appropriate exposure time) was not impaired, and development was allowed. I was able to expand my sex.

When the printing plate obtained as described above was printed using an offset printing machine, a large number of prints with good images were obtained.

Examples 7 to 12 and Comparative Example b Lithographic printing plates 7 to 12 and Comparative Example b were prepared in the same manner as in Examples 1 to 6 except that the photosensitive solution was changed to the following.

As can be seen from Table 2, in Examples 7 to 12 in which the nonionic surfactant was added, the development acceptability could be broadened without impairing the sensitivity, as compared with Comparative Example b.

Examples 13-18 and Comparative Example c The photosensitive coating solution having the above composition is electrochemically roughened,
And applied to an anodized aluminum plate. The film weight after drying at this time was 2.3 g / m ² . The optimum exposure amount and the development allowance of the positive type photosensitive lithographic printing plate thus obtained are shown in Table 3. By adding a nonionic surfactant,
It can be seen that the development tolerance could be expanded without impairing the sensitivity.

Examples 19 to 22 and Comparative Examples d to f In the photosensitive solutions of Examples 1 to 6, the nonionic surfactant was changed as shown in Table 4 below to obtain photosensitive lithographic printing plates. Each of these photosensitive lithographic printing plates was exposed with a 1.5 kw metal halide lamp and then developed with an 8 times dilution of DP-4 at 25 ° C. for 30 seconds. The appropriate exposure time at this time was a point where 5 steps were completely clear on a gray scale with a density difference of 0.15, and this was taken as the sensitivity. Further, development was performed with a 6-fold diluted solution of DP-4, and the development tolerance was determined in the same manner as in Examples 1-6. As shown in Table 4, in Examples 19 to 22, the development tolerance could be expanded without deteriorating the sensitivity.

Examples 23 to 25 and Comparative Examples g to i In the photosensitive liquids of Examples 7 to 12, the nonionic surfactant was changed as shown in Table 5 below to obtain photosensitive lithographic printing plates.

These photosensitive lithographic printing plates were evaluated in the same manner as in Examples 19-22. As shown in Table 5, in Examples 23 to 25, the development acceptability could be expanded without impairing the sensitivity.

Examples 26 to 28 and Comparative Examples j to l In the photosensitive liquids of Examples 13 to 18, the nonionic surfactant was changed as shown in Table 6 below to obtain photosensitive lithographic printing plates.

These photosensitive lithographic printing plates were evaluated in the same manner as in Examples 19-22. As shown in Table 6, in Examples 26 to 28, the development acceptability could be expanded without impairing the sensitivity.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Matsumoto 4000 Kawajiri, Yoshida-cho, Hara-gun, Shizuoka Prefecture Fuji Shashin Film Co., Ltd. (56) Reference JP 61-7837 (JP, A) JP 57 -40249 (JP, A) JP-A-60-208749 (JP, A) JP-A-60-74621 (JP, A)

Claims (2)

[Claims] 1. A positive photosensitive lithographic printing plate comprising a support and a positive photosensitive composition containing an o-quinonediazide compound, wherein the positive photosensitive composition contains a nonionic surfactant. The nonionic surfactant contains polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, It is selected from the group consisting of fatty acid monoglyceride, sorbitan fatty acid ester, pentaerythritol fatty acid ester, propylene glycol fatty acid ester, polyglycerin fatty acid ester, and a mixture of two or more thereof. The positive photosensitive lithographic printing plate to. 2. The positive photosensitive lithographic printing according to claim 1, wherein the nonionic surfactant is 0.1 to 20% by weight based on the total weight of the photosensitive composition. Edition.