JPH0223348A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To widen the latitude of developability and to prevent the generation of scumming at the time of printing by providing a photosensitive layer contg. an O-quinone diazide compd. on a base subjected to a surface treatment with the sol of the compd. of a metal. CONSTITUTION:The photosensitive layer contg. the O-quinone diazide compd. is provided on the base of the subjected to the surface treatment with the sol of the compd. of the metal. The sol of the compd. of the metal consists of an oxide or hydrate and the metal forming such sol included, for example, Al, Ti, Zr, Cr, Ni, Zn, Sn, Mn, etc., and at least one kind of the sols of the compds. of such metals are used. The Al, Cr, Ni, Zn are preferably used. The O-quinone diazide compd. is exemplified by, for example, the esterified compds. of O-naphthoquinone diazide sulfonic acid and a polycondensation resin of phenols and aldehyde or ketone. The development latitude is widened in this way and the generation of stains at the time of printing is prevented in this way and the ease and workability of printing are improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a photosensitive lithographic printing plate using an iron material as a support, and in particular, a photosensitive planographic printing plate containing an 0-quinonediazide compound on the iron material which has been subjected to a special hydrophilic treatment. The present invention relates to a photosensitive lithographic printing plate having a photosensitive layer.

[Background of the invention]

Supports for photosensitive lithographic printing plates include paper, plastic or laminates; paper, aluminum, zinc, iron,
Metal plates such as copper, plastic films, paper or plastic films plated, laminated or vapor-deposited with the above-mentioned metals are known.

However, these conventional supports have any of the following drawbacks.

(1) If the hardness of the support surface is insufficient, the surface of the non-image area or the image area may be damaged by printing a large number of sheets.
As a result, stains occur in non-image areas during printing, or ink buildup defects occur in image areas.

(2) If the hydrophilicity and water retention of the support surface are insufficient, stains may occur during printing, or the width of the dampening solution may be narrow, resulting in printing that is difficult to print.

(3) If the adhesion of the ink-receptive material to the surface of the support is insufficient, the image area during printing will be severely damaged and cannot withstand printing on a large number of sheets.

(4) If the bending strength or tensile strength of the support is insufficient, gripping or plate breakage may occur during printing.

For example, aluminum plates, which are most effectively used in this area, require grain treatment and anodization to provide sufficient hydrophilicity, water retention, and adhesion, making the manufacturing process complicated. At the same time, it is extremely costly,
The current situation is disadvantageous.

Iron materials have been developed as supports for photosensitive planographic printing plates, which have characteristics such as being inexpensive, having high mechanical strength, and being magnetic. For example, JP-A-55-145
No. 193, No. 58-220796 and No. 59-311
As described in JP-A No. 92, etc., an iron support having a chromium electrodeposition layer, JP-A-56-130395 and JP-A-56
-130396, 56-150592 and 57
As described in Japanese Patent Application No. -64597, iron supports whose surfaces are roughened by electroforming are known. or,
In general, lithographic printing plates are printed using water and lipophilic ink, and in order to obtain a large number of good prints, it is necessary to improve the oiliness of the image area and the hydrophilicity of the non-image area (hydrophilicity of the support).
must be sufficient. In order to improve the hydrophilicity of the iron support, JP-A Nos. 58-220797 and 59-
As described in Japanese Patent No. 11294, a hydrophilic treatment method is known in which treatment is performed with a mixed aqueous solution of a water-soluble polymer and a water-soluble metal salt or an aqueous potassium permanganate solution.

However, photosensitive lithographic printing plates using these supports have the problem of poor removal of the photosensitive layer in non-image areas during development, that is, narrow tolerance of developability, and problems with hydrophilicity in non-image areas. As a result, background smudges tend to occur during printing, resulting in poor printing workability.

[Problem to be solved by the invention]

Therefore, it is an object of the present invention to provide a photosensitive lithographic printing plate that has a wide developability tolerance, is highly hydrophilic in non-image areas, and uses an iron material as a support that is less prone to background staining during printing. .

[Means to solve the problem]

The above object of the present invention is achieved by a photosensitive lithographic printing plate having a photosensitive layer containing an 0-quinonediazide compound on a support whose surface has been treated with a sol of a metal compound.

The present invention will be explained in detail below.

The iron support of the present invention can be obtained by roughening the surface of an iron material, subjecting it to plating or post-plating chemical conversion treatment, and further surface treatment with a sol of a metal compound.

The iron material in the present invention includes not only pure iron but also alloys of iron and other elements. Other elements that form alloys with iron include carbon, manganese, and nickel. As an alloy,
Specifically, carbon steel (an alloy of carbon (0.04-1.7%) and iron), cast iron with a higher carbon content than carbon steel, and also other elements (for example manganese).

Examples include special steels containing (nickel, chromium, cobalt, tungsten, molybdenum) (for example, manganese steel, nickel steel, chromium steel, nickel-chromium steel). The above-mentioned carbon steels include extremely mild steel (carbon 0.25% or less), mild steel (0.25 to 0.5%), hard steel (carbon 0.5 to 1.0%),
%), extremely hard steel (carbon 1.0% or more).

Various conventionally known methods can be used to roughen the surface of the iron material, including mechanical methods, chemical methods, and electrolytic methods. Examples of mechanical methods include polishing methods, brush polishing methods, and polishing methods using liquid honing. Chemical methods include etching with a solution containing sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, oxalic acid, pyrophosphoric acid, ferric chloride, etc. The electrolytic method includes an electrolytic etching method and an electrolytic plating method.

Roughening t: The subsequent plating treatment uses Ni, Cr, Cu, or Sn, which has a rust-preventing effect on iron materials.

Note that the plating metal is not limited to the above-described single metal, but also includes an alloy containing one or more of these metals, or a composite plating of two or more of these metals.

After plating, the chemical conversion treatment that is performed as necessary is immersion in a solution containing chromate, dichromate, phosphate, molybdate, borate, perborate, etc., or in the solution. There is a chemical conversion treatment method using electrolysis.

The center line average roughness (as indicated in DIN 4768) of the surface of the support obtained by the above treatment is 0.
The thickness is 1 to 3μ, preferably 0.3 to 15μ.

The surface treatment performed after plating with a sol of a metal compound is a hydrophilic treatment, and this treatment may be applied to both the front and back surfaces of the support.

A sol of a metal compound is composed of an oxide or a hydrate, and examples of metals forming such a sol include Al.
1. Ti, Zr, Cr, Ni, Zn, Sn, Mn, C
u, Co, Fe.

There are Pb, Cd, Mg, Ca, etc., and in the present invention, at least one kind of sols of compounds of these metals is used, and 80, Cr, Ni, and Zn are preferably used.

As the hydrophilic treatment method, cathodic electrolysis or immersion treatment is preferably performed in an aqueous solution containing a sol of the metal compound. The concentration of a sol of a metal compound in an aqueous solution is l-10
0 g/Q is preferred. In addition, inorganic salts such as chromic acid, phosphoric acid, and sulfuric acid, and citric acid are added to the treatment solution to improve the stability of the sol in an aqueous solution.

An organic acid such as acetic acid or a surfactant can be added.

The cathode electrolysis conditions vary depending on the type of sol used, but the current density is 0.5 to IOA/ds'', the treatment temperature is 5 to 50°C, and the treatment time is 1 to 60 seconds.

The photosensitive lithographic printing plate of the present invention can be produced by coating the iron support obtained above with a photosensitive composition containing an 0-quinonediazide compound using, for example, an organic solvent.

In the photosensitive composition containing the 0-quinonediazide compound of the present invention, it is preferable to use the 0-quinonesia-cyto compound and an alkali-soluble resin together.

Examples of the O-quinonediazide compound in the present invention include ester compounds of O-su7toquinonediazide sulfonic acid and polycondensation resins of phenols and aldehydes or ketones.

Examples of the phenols include phenol, 0-
Cresol, Otori-cresol, p-cresol, 3.5
- Monohydric phenols such as xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and 70 loglucin. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Preferred among these are formaldehyde and benzaldehyde. Further, examples of the ketone include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, -cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, resorcinol benzaldehyde resin, pyrogallol/acetone resin, and the like.

O) of the phenols of the 0-naphthoquinonediazide compound! The condensation rate of 0-naphthoquinonediazide sulfonic acid with respect to groups (reaction rate with respect to one OH group) is 15 to 80
%, more preferably 20 to 45%.

Further, as the O-quinonediazide compound used in the present invention, the following compounds described in JP-A-58-43451 can also be used. That is, for example, known 1,2-benzoquinonediazide sulfonic acid ester, 1,2-naphthoquinonediazide sulfonic acid ester, 1,2-benzoquinonediazide sulfonic acid amide, 1,2-7-toquinonediazide sulfonic acid amide, etc. - quinonediazide compounds, more specifically J. Kossar
“Light Sensitive System” (“Li
ght-Sensitive 5yste++s”) No. 339-352N (1965), John Willey & Sons
ons) (New York) and W. I. Nissude (-"7 Orest (11, S, De Forest), "Photoresist", Vol. 50.

(1975), McGraw-Hill (McGray-Old 1
1) 1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, 1
．． 2.1'2'-C benzoquinonediazide-4.sulfonyl)-dihydroxybiphenyl, 1.2.benzoquinonediazide-4-(N-ethyroot β-naphthyl)
-Sulfonamide, 1,2-naphthoquinonediazide-5
-sulfonic acid cyclohexyl ester, 1-(1,2-
7-toquinonediazide-5-sulfonyl)-3,5-dimethylpyrazole, 1,2-naphthoquinonediazide-5
-Sulfonic acid-4'.hydroxydiphenyl-4'.azo-β-7tol ester, N,N-di(l,2-
7-toquinone diazido-5-sulfonyl)-aniline,
2'-(1,2-naphthoquinonediazide-5-sulfonyloxy)/l-hydroxy anthraquinone, 1.2
-Naphthoquinonediazide 5-sulfonic acid-2゜4-dihydroxybenzophenone ester, 1.2-naphthoquinonediazide-5-sulfonic acid-2,3,4-trihydroxybenzophenone ester, 1.2-naphthoquinonediazide 5- 2 moles of sulfonic acid chloride and 4.4'
- condensate of 1 mole of diaminobenzophenone, condensate of 2 moles of 1.2.naphthoquinone diazido-5-sulfonic acid chloride and 1 mole of 4.4'-dihydroxy-1,1'-diphenylsulfone, l, 2-su7 Toquinone diazide 5
Examples include a condensate of 1 mol of -sulfonic acid chloride and 5921 mol of purpuro, and 1,2-quinonediazide compounds such as 1,2-naphthoquinonediazide.5-(N-dihydroabiethyl)-sulfonamide. Also, Special Publication No. 37/1953, No. 37-3627, No. 37-1
No. 3109, No. 40-26126, No. 40-3801
No. 45-5604, No. 45.27345, No. 5
1-13013, JP-A-48-96575, JP-A No. 48
The 1,2-quinonediazide compounds described in Japanese Patent No. 63802 and No. 48-63802 can also be mentioned.

Among the above 0-quinonediazide compounds, 0-quinonediazide is obtained by reacting 1.2-benzoquinonediazide sulfonyl chloride or 1.2-naphthoquinonediazide sulfonyl chloride with pyrogallol acetone condensation resin or 2.3.4-trihydroxybenzophenone. Ester compounds are particularly preferred.

As the O-quinonediazide compound used in the present invention, each of the above compounds may be used alone, or two or more thereof may be used in combination.

The proportion of the O-quinonediazide compound used in the present invention in the photosensitive composition is preferably 5 to 60% by weight,
Particularly preferably, it is 10 to 50% by weight.

Examples of the alkali-soluble resin used in the photosensitive composition of the present invention include a novolak resin, a vinyl polymer having a phenolic hydroxyl group, a polyhydric phenol and an aldehyde described in JP-A-55-57841, or Examples include condensation resins with ketones.

Examples of the novolak resin used in the present invention include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A-55-57841, JP-A-55-57841; Examples include a copolycondensate resin of p-substituted phenol, phenol, and cresol and formaldehyde as described in Japanese Patent Publication No. 55-127553.

The molecular weight (polystyrene standard) of the novolak resin is:
Preferably, the number average molecular weight Mn is 3.00X 10” to 7
．． 50X 103, weight average published 1w is 1.00X 1
0' to 3.00×10', more preferably Mn is 5. O
OX 10"~4.00X10", My is 3.00X
10" to 2.00X 10'.

The above novolak resins may be used alone or in combination of two or more.

The proportion of the novolak resin in the photosensitive composition of the present invention is 5 to 95% by weight.

Further, the vinyl polymer having a phenolic hydroxyl group used in the present invention is a polymer having a unit having the phenolic hydroxyl group in its molecular structure, and the following - binding margin C
Polymers containing at least one structural unit of I) to (V) are preferred.

-Tsuri allowance (1) General formula [■] General formula (I [I) General formula (IV) H General formula [v] In the formula, R1 and R2 each represent a hydrogen atom, an alkyl group, or a carboxyl group, preferably It is a hydrogen atom.

R1 represents a hydrogen atom, a hydrogen atom, or an alkyl group, preferably a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R4 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom. A represents an alkylene group which may have a substituent and which connects a nitrogen atom or an oxygen atom and an aromatic carbon atom, and i
f! represents an integer of O"IO, and B represents a phenylene group which may have a substituent or a naphthylene group which may have a substituent.

The polymer used in the photosensitive composition of the present invention preferably has a copolymer type structure, and the above-mentioned binding margin [■
Examples of monomer units that can be used in combination with the structural units represented by [v]] to [v] include, for example, ethylene,
Ethylenically unsaturated olefins such as propylene, isobutylene, butadiene, isoprene, etc., lf styrene,
Styrenes such as α-methylstyrene, p-methylstyrene, and p-chlorostyrene; acrylic acids such as acrylic acid and methacrylic acid; unsaturated aliphatic dicarboxylic acids such as itaconic acid, maleic acid, and maleic anhydride; Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl a-chloroacrylate, methyl methacrylate,
Esters of monomethylene aliphatic monocarboxylic acids such as ethyl methacrylate and ethyl ethacrylate, nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, p-chloroacrylanilide, m-di Anilides such as troacrylanilide and heel-methoxyacrylanilide, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, such as methyl vinyl ether, ethyl vinyl ether, inbutyl vinyl ether, β-chloroethyl vinyl ether vinyl ethers such as vinyl chloride, vinylidene chloride, vinylidene cyanide, such as l-methyl-1-
Methoxyethylene, l,1-dimethoxyethylene, ■,
Ethylene derivatives such as 2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, l-methyltonitroethylene, such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylvirolone, N-vinylpyrrolidone There are N-vinyl compounds such as, and vinyl monomers such as. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above-mentioned monomers, esters of aliphatic monocarboxylic acids and nitriles are preferred because they exhibit excellent performance for the purpose of the present invention.

These monomers may be bound in the polymer of the present invention in either a block or random manner.

The proportion of the vinyl polymer used in the present invention in the photosensitive composition is 0.5 to 70% by weight.

As the vinyl polymer used in the present invention, the above-mentioned polymers may be used alone or in combination of two or more.

Moreover, it can also be used in combination with other polymer compounds.

In addition to the above-mentioned materials, the photosensitive composition of the present invention may optionally contain pigments such as dyes and pigments, plasticizers, surfactants, fluorocarbon surfactants, organic acids, and acid anhydrides. , a compound that can generate an acid upon exposure to light, etc. can be added.

Furthermore, the photosensitive composition of the present invention may contain, for example, p-tert-butylphenol formaldehyde resin, p-n-octyl 7-ninol formaldehyde resin, or 0- It is also possible to add resins partially esterified with quinonediazide compounds.

The photosensitive lithographic printing plate of the present invention can be produced by dissolving each of these components in the following solvent and applying and drying the solution on the surface of the support of the present invention to provide a photosensitive layer.

Solvents that can be used to dissolve each component of the photosensitive composition of the present invention include methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, diethylene glycol 7-methyl ether, diethylene glycol 7-ethyl ether, diethylene glycol dimethyl ether, Diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether
Tertel, propylene glycol, propylene glycol 7-methyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether,
Dipropylene glycol methyl ethyl ether, ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, dimethyl formamide, dimethyl sulfoxide Ruethyl ketone, cyclohexanone, methylcyclohexanone, diacetone alcohol, acetylacetone, γ
-butyrolactone, etc.

These solvents can be used alone or in combination of two or more.

The coating method used for coating the surface of the support with the photosensitive composition of the present invention includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating. Coating etc. are possible. At this time, the coating amount varies depending on the application, but is preferably 0.05 to 5.0 g/m'' in terms of solid content.

When using the photosensitive lithographic printing plate thus obtained,
Conventionally used methods can be applied, for example, by exposing a transparent original image having a line image, halftone image, etc. in close contact with a photosensitive surface, and then developing this with an alkaline aqueous solution. A positive relief image is obtained.

Suitable light sources for exposure include mercury lamps, metal halide lamps, xenon lamps, chemical lamps, and carbon arc lamps, and alkaline aqueous solutions used for development include sodium silicate, potassium silicate, sodium hydroxide, and potassium hydroxide. There are alkaline aqueous solutions such as aqueous solutions of tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate, etc. The concentration of the alkaline aqueous solution at this time varies depending on the photosensitive composition and the type of alkali, but is generally in the range of 0.1 to 10% by weight. It is also possible to add organic solvents such as.

〔Example〕

EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples unless the gist of the invention is exceeded.

Preparation of support = 1 A flat surface of a steel plate with a thickness of 0 and 15 mm was roughened by etching with a Baume 40' ferric chloride solution, and a sulfate bath was used for this, at a temperature of 50° C. and a current density of 5 A/da2. After plating Zn with a thickness of 4 μm under the following conditions, a particle size of 1
00mm Cr sol 20gIQ, phosphoric acid lOgIQ
Electrolysis was performed for 30 seconds at a current density of 2A/d+11'' using a steel plate as a cathode with a solution containing
I got it.

Preparation of Photosensitive Lithographic Printing Plate Sample-1 A photosensitive composition coating liquid (1) having the following composition was coated on the support-1 prepared as described above using a rotary coating machine, and the coating solution was coated at 90°.
The sample was dried at C for 4 minutes to prepare photosensitive lithographic printing plate sample-1.

(Photosensitive composition coating liquid (1) composition) ・Novolac resin A*' 6.7 g
・0-quinonediazide compound 1.5 g
*2 (QD-1) ・Surfactant-1830.2 g ・Victoria Pure Blue B O H 0.0
8g (manufactured by Hodogaya Chemical Co., Ltd.) ・Compound that generates halogen free radicals 0.15g (r
ad 1*4) Methyl cellosolve 100mQ Preparation of photosensitive lithographic printing plate sample-2 Coating the photosensitive composition coating liquid (2) having the following composition onto the support 1 prepared above in the same manner as above. A photosensitive lithographic printing plate sample-2 was prepared.

(Photosensitive composition coating liquid (2) composition) - Novolac resin A*16.3 g - 0-quinonediazide compound 1.9 g
*2 (QD-2) ・Surfactant-21￥43 0.3g
・Victoria Pure Blue B OH0.07g (manufactured by Fukadogaya Chemical Co., Ltd.) ・Compound that generates halogen free radicals 0.13g (r
ad 2*4) ・Methyl cellosolve 100mff
Preparation of Photosensitive Planographic Printing Plate Sample-3 A photosensitive composition coating liquid (3) having the following composition was coated on Support -1 in the same manner as described above to prepare Photosensitive Planographic Printing Plate Sample-3.

(Photosensitive composition coating liquid (3) composition) - Novolac resin A 6.3 g
・Polymer A*5 0.3 g・
0-quinonediazide compound 1.9 g*
2 (QD-3) ・Surfactant-3'30.3 g ・Victoria Pure Blue B OHO, 07 g (manufactured by Fukatogaya Chemical Co., Ltd.) ・Compound that generates halogen free radicals 0.13 g (r
ad-3*4) ・Methyl cellosolve 100m12
Preparation of Support-2 The surface of a rolled steel foil with a thickness of 0.0 h++o was plated with 5 μm of Fe to give a surface roughness of 0.4 μl, and then heated in a Sargent bath at a temperature of 45° C. and a current density of 40 A/dl12.
Cr plating with a thickness of 0.1 μm was performed under the following conditions, and alumina sol with a particle size of 50 μl (alumina sol-200° manufactured by Nissan Chemical) was applied with hydrophilic treatment, 30 g/Q, chromic acid 5 g/
Support 2 was obtained by immersing it in an aqueous solution containing 12 and drying it.

Preparation of Photosensitive Planographic Printing Plate Sample-4 The photosensitive composition coating liquid (1) was coated on the support 2 prepared as above in the same manner as described above to obtain Photosensitive Planographic Printing Plate Sample-4. was created.

Preparation of Support-3 In the preparation of Support-1, as a hydrophilic treatment, it was immersed in an aqueous solution of carboxymethyl cellulose sodium salt and calcium acetate (0.07% by weight each) at room temperature for about 1 minute, washed with water, and dried. Support-3 was obtained in the same manner as in the preparation of Support-1 except for the following steps.

Preparation of Photosensitive Planographic Printing Plate Sample-5 A photosensitive [acid coating solution (1)] was coated on the support 3 prepared as above in the same manner as above, and photosensitive planographic printing plate sample-5 was prepared. Created.

Preparation of Support-4 In the preparation of Support-2, all supports were used, except that 4% by weight was immersed in an aqueous potassium permanganate solution for 1 minute at 40°C, washed with water, and dried. Support-4 was obtained in the same manner as in the preparation of Support-1.

Preparation of Photosensitive Planographic Printing Plate Sample-6 The photosensitive composition coating liquid (1) was coated on the support-4 prepared as above in the same manner as described above to obtain Photosensitive Planographic Printing Plate Sample-6. Created.

*l Novolac resin A Copolycondensation resin of phenol, m-cresol, p-cresol, and formaldehyde (the molar ratio of phenol, m-cresol, and p-cresol is 2.0:, 4
．． 8: 3.2, Mv-6,500, My/Mn-
5,4) *2o-quinonediazide compound QD-1; QD-2; n x/y=1/3 My" of resin before reacting with QD 1,900QD-
3; My-1,600*3 of the resin before reacting with QD Surfactant Surfactant-1 Emulgen 120 (manufactured by Kao Corporation); Polyoxyethylene lauryl ether surfactant-2 Emulgen 91O (manufactured by Kao Polyoxydiethylene nonylphenyl ether surfactant-3 Rheodol TW-S120 (manufactured by Kao Corporation); Polyoxyethylene sorbitan monostearate*4 Compound radl that generates halogen free radicals; 2-
Trichloromethyl 5-(p-methoxystyryl)-1
,3,4-oxadiazole (JP-A-54-74728
Compound described in Example 1 of the publication) rad-2; 2,4-bis(trichloromethyl)-6-
p-methoxystyryl-8-triazine (Unexamined Japanese Patent Publication No. 1973-
36281 Publication Example 1) rad 3;2-)lichloromethyl-5-[β-(2
-benzofuryl) vinyl 11,3,4-oxadiazole (exemplified compound (1) described in JP-A-60-138539) *5 Polymer A JH Examples 1 to 4 Obtained as described above Photosensitive planographic printing plate sample No.
, 1-No., and step tablet for sensitivity measurement on 4 (
Eastman Kodak No. 2. Density difference 0.15
(21 levels of gray scale) in close contact with each other, 2kW
Metal halide lamp (idle fin 2 manufactured by Iwasaki Electric Co., Ltd.)
000) as a light source8. Exposure was carried out under the condition of Omv/c+a2.

In order to evaluate the development tolerance, the above-exposed sample was exposed to 5DR-1 (manufactured by Konica Corporation) with water at a magnification of 6 times and 9 times.

After developing for 40 seconds at 25°C with a developer diluted 11 times or 13 times, ink was applied with developing ink (spo-1 manufactured by Konica, Inc.) to check the developability (removability) of the non-image area.
observed.

Next, in order to evaluate the resistance to staining during printing, a printing test was conducted using a Heidel printing machine.

The sample was a photosensitive planographic printing plate sample No. 1 = No. 4, with a positive original having halftone dots and line drawings in close contact with it, and a 2 kW metal halide lamp (idle fin 2000 manufactured by Iwasaki Electric Co., Ltd.).
8. as a light source. After exposure under the condition of "On+w/co+", 5DR-1 (manufactured by Konica Corporation) was diluted 6 times with water and developed with a developer at 25 DEG C. for 40 seconds.

The sample thus obtained was applied to a Heidel printing machine, and ink (New Bright G Red, manufactured by Toyo Ink Manufacturing Co., Ltd.) was applied to the entire surface of the printing plate, and after being left as it was for 10 minutes, soaking water (SEU -3. The number of prints (high-quality paper was used as the printing paper) was counted until normal prints were obtained.

The above evaluation results are shown in Table 1.

Comparative Examples 1-2 Photosensitive lithographic printing plate samples No. 5-N obtained above
The samples were treated and evaluated in exactly the same manner as in Examples 1 to 4 using No. 0 and No. 6. The evaluation results are shown in Table 1.

Table 1 * ※※ 0: Ink does not adhere to non-image areas.

×: Ink adheres to non-image areas.

If the number of sheets exceeds 50, the printing workability will be poor and this will pose a practical problem.

〔Effect of the invention〕

The photosensitive lithographic printing plate according to the present invention has wide development latitude,
Compared to conventional photosensitive lithographic printing plates, it can be developed with a low-concentration alkaline developer, and the life of the developer can be extended. Furthermore, the lithographic printing plate of the present invention obtained by development was resistant to staining during printing, was easy to print, and had improved printing workability.

Claims (1)

[Claims] A photosensitive lithographic printing plate comprising a photosensitive layer containing an o-quinonediazide compound on a support whose surface has been treated with a sol of a metal compound.