JPH02212846A - Photosensitive planographic printing plate - Google Patents

Abstract

PURPOSE:To maintain a sufficient water retentivity in a non-image part while maintaining a high plate wear resistance and to obviate generation of stains in a non-image part by processing the surface of an aluminum base using a specific processing. CONSTITUTION:After the pretreated surface of the base is processed with an aq. soln. contg. sulfinic acid or sulfinate, a photosensitive layer is provided on the surface thereof. As a result, the components in the photosensitive layer, more particularly the resin components which are generally strongly adsorbed to the non-image part and are difficult to be removed are easily removed at the time of developing the photosensitive planographic printing plate. The excellent developability is obtd. and the sufficient water retentivity is maintained in the non-image part. In addition, the plate wear resistance is enhanced and the generation of the stains in the non-image part is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate having an improved parent layer.

[Conventional technology]

Conventionally, a photosensitive lithographic printing plate, such as a positive-working photosensitive printing plate, has an ink-receptive photosensitive layer provided on a support having a parent layer. When image exposure is performed and the exposed photosensitive layer is then developed using a developer, the photosensitive layer in the exposed areas is removed and the surface of the hydrophilic support is exposed, while the photosensitive layer in the exposed areas is removed from the support. It remains on the surface to form ink-receptive image areas, thereby yielding a lithographic printing plate.

Such a lithographic printing plate uses the repulsion between water and oil to perform printing. Specifically, when the non-image area of the printing plate is moistened with water and then ink is applied to the printing plate, the ink is repelled by the dampening water in the non-image area, so that the ink selectively adheres only to the image area. When the ink in the image area is transferred to a transfer object, a printed matter having an image corresponding to the image area is obtained.

Therefore, as a support for obtaining such a lithographic printing plate, it is necessary to use a support that has excellent hydrophilicity and water retention properties, and also has good adhesion to the photosensitive layer that forms the image area that receives printing pressure. It must be in good condition. Furthermore, the photosensitive layer must have ink receptivity and high sensitivity to light exposure, and most importantly, it must have high printing durability.

An aluminum plate is the best support that satisfies these conditions, and in order to obtain sufficient adhesion between the aluminum plate and the photosensitive layer, a surface treatment method is used to mechanically roughen the surface of the support. As, for example, Paul Daleining,
Various methods such as wire graining and brush graining are described in Japanese Patent Publication No. 50-40047 and Japanese Patent Publication No. 51-46 (1983).
It is described in Publication No. 103, etc. Also, special public show 4g-2
No. 8123, U.S. Pat. An electrolytic surface roughening method that forms a dense grained shape is described. Furthermore, JP-A-56-150595
The publication describes a method of controlling the adhesion between the support and the photosensitive layer by subjecting the surface of the support to a sealing treatment using hot water, a sealing treatment using a silicate, or the like.

In addition to providing sufficient adhesion between the support and the photosensitive layer, the support such as an aluminum plate is further subjected to surface treatment to improve its hydrophilicity and water retention. Publication No. 56-22063, U.S. Patent No. 2.246.683, U.S. Patent No. 3.160.50
No. 6 describes that the hydrophilicity and water retention of the metal surface can be improved by chemically treating the metal surface with potassium fluorozirconate to form a film. Further, JP-A-53-13NO2 describes a support whose hydrophilicity and water retention are improved by treating it with an aqueous solution of potassium fluorozirconate and then with an aqueous solution of sodium silicate.

However, these methods: 1. If the stain prevention effect of the non-image area of the lithographic printing plate obtained by development treatment is sufficiently improved, problems will arise in printing durability and chemical resistance, and it is difficult to improve printing durability and processing chemical resistance. The effect of preventing staining in the image area was insufficient, and it was difficult to improve the prevention of staining in the non-image area, printing durability, and treatment chemical resistance.

Such a phenomenon occurs when burning treatment, which is commonly used as a means of improving stiffness resistance, occurs -RM
It has become increasingly clear that the lithographic printing plates obtained from supports treated according to Method I are no longer suitable for practical printing use.

Therefore, as a result of extensive research in view of the above-mentioned problems, the inventors of the present invention have mainly treated the surface of the aluminum support using a specific treatment, thereby maintaining high printing durability while at the same time The present inventors have discovered that a photosensitive lithographic printing plate can be obtained which maintains sufficient water retention and does not cause staining in non-image areas, and has completed the present invention.

[Purpose of the invention]

Therefore, the first object of the present invention is to provide a photosensitive lithographic printing plate that has excellent developability, in which no components of the photosensitive layer remain in non-image areas after exposure and development, and maintains sufficient water retention in non-image areas. Our goal is to provide the following.

A second object of the present invention is to provide a photosensitive planographic printing plate that has high printing durability and does not cause stains in non-image areas.

[Structure of the invention]

The above-mentioned object of the present invention is to provide a photosensitive lithographic printing plate characterized in that the surface of a pretreated support is treated with an aqueous solution containing sulfinic acid or a sulfinate salt, and then a photosensitive layer is provided on the surface. achieved.

[Effect]

In the present invention, after the surface of the support is pretreated, this surface is further treated with an aqueous solution containing sulfinic acid or a sulfinate, so that when a photosensitive lithographic printing plate is developed, the non-image area is Components in the photosensitive layer that were strongly adsorbed and could not be removed, especially resin components, can be easily removed, so that water retention in non-image areas can be maintained sufficiently.

[Detailed description of the invention]

The present invention will be explained in more detail below.

The present invention is characterized in that before forming a photosensitive layer on the surface of a pretreated support, the surface is treated with an aqueous solution containing Sulfy 7a or a sulfinate, thereby preventing staining of non-image areas. and improves water retention.

Examples of sulfinate salts used in the present invention include I a s na - II b N I of the periodic table.
II b %DIb, IVa, rVb, VIa, ■a1
Examples include sulfinates or ammonium salts of group metals, i.e., ammonium sulfinate; examples of the metal salts include Li5O, H, Na5OJ, K
SO,H,Mg(SOzH)iCa(SO2[l)z,
Zn(SOxH)x, Al(SO!H)s, Zr(so
, tl),, So(Sow)I) Cr(SOx
H)s, Co(SJH)z, Mn(SOzH)*,
Nj(SOJ) and the like are preferred, and alkali metal sulfinates are particularly preferred. Of course, two or more kinds of such sulfinate salts can be used in combination, and further, they can also be used in combination with sulfinic acid.

The aqueous solution containing sulfinic acid or sulfinate salt used in the present invention is generally an aqueous solution containing o, ooi to 10% by weight of sulfinic acid or sulfinate salt.

When treating the surface of the support with the above treatment liquid, the treatment conditions include immersing the pretreated support for 15 to 300 seconds at a temperature range from room temperature to about 100°C, or supporting the treatment liquid. Preferably applied to the body.

In a preferred embodiment of the present invention, an aqueous solution containing 0.01 to 2% by weight of sodium sulfinate is added at 50 to 80°C.
For example, the support may be immersed for 30 to 180 seconds. The support treated with an aqueous solution containing sulfinic acid or sulfinate is then preferably dried.

Additives can be added to the aqueous solution containing the sulfinic acid or sulfinate salt, if necessary. Examples include water-soluble polymers and surfactants.

The support used in the present invention is preferably one that is flexible enough to be run on a normal lithographic printing machine and that can withstand the load applied during printing, such as a metal plate made of aluminum, magnesium, zinc, chromium iron, copper nickel, etc. and alloy plates of these metals, and metal plates coated with chromium, zinc, copper, aluminum, iron, etc. by metal plating or vapor deposition may also be used.

Among these, a preferred support is aluminum or an alloy thereof.

The support used in the present invention is pretreated before being treated with an aqueous solution containing sulfinic acid or a sulfinate salt. There is a noticeable treatment.

Graining is a method of mechanically roughening the surface, and is referred to as a so-called mechanical surface roughening method, and includes methods such as pole polishing, brush polishing, plastokenma, and puff polishing.

It is also possible to use a so-called electrical surface roughening method that electrically roughens the surface. For example, the support can be subjected to electric field treatment using alternating current or direct current in an electrolytic solution containing hydrochloric acid, nitric acid, etc. can.

Scots are formed on the surface of the support obtained by the above-mentioned grain treatment, so in order to remove these scotts, it is generally necessary to carry out treatments such as water washing or alkali etching as appropriate. preferable. Examples of such treatments include the alkali etching method described in Japanese Patent Publication No. 48-28123 and the sulfuric acid descott method described in Japanese Patent Application Laid-open No. 53-12739.

When the support used in the present invention is an aluminum support, after the above-mentioned pretreatment, the support is usually anodized to improve wear resistance, chemical resistance, and water retention. to form an oxide film. In this anodic oxidation, sulfuric acid and/or phosphoric acid is generally used at a concentration of lO to 50
Current density 1 to IOA/d using an aqueous solution containing % as an electrolyte
Although a method of electrolyzing with m2 is preferably used, other methods include electrolysis with R as described in US Pat. No. 1,412.768
Method of electrolysis at high current density in acid and U.S. Patent No. 3,51
There is a method of electrolysis using phosphoric acid described in the specification of No. 1.661.

The most preferred support for use in the present invention is an aluminum support with an anodized coating. - The treatment applied to the support itself to improve the adhesion of the support to the photosensitive layer is not particularly limited, and a primer layer or the like may be provided as necessary.

The primer layer includes, for example, polyester resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, vinyl chloride resin, polyamide resin, polyvinyl butyral resin, epoxy resin, acrylate copolymer, vinyl acetate copolymer, phenoxy resin. , polyurethane resin, polycarbonate resin, polyacrylonitrile butadiene, polyvinyl acetate, and the like.

In addition, as the anchor agent constituting the above-mentioned brimer layer,
For example, silane coupling agents, silicone primers, etc. can be used, and organic titanates and the like are also effective.

The photosensitive lithographic printing plate of the present invention has a photosensitive layer provided on the support obtained as described above, but the photosensitive material used in this photosensitive layer is not particularly limited. Various types of materials commonly used in photosensitive lithographic printing plates, such as those listed below, are used.

l) Photocrosslinkable photosensitive resin composition The photosensitive component in the photocrosslinkable photosensitive resin composition is composed of a photosensitive resin having unsaturated double bonds in its molecules, for example as described in U.S. Pat. No. 3.030. .208 Specification, Nos. 3 and 4
Photosensitive resins and polymers containing -CH-CH-Co- as a photosensitive group in the polymer main chain, as described in No. 35.237 and No. 3.622,320, etc. Examples include polyvinyl cinnamate having a photosensitive group in the side chain.

2) Photopolymerizable photosensitive resin composition A photopolymerizable composition containing an addition-polymerizable unsaturated compound, consisting of a monomer having a double bond and a polymer binder, and a typical example of such a composition. For example, US Pat. No. 2,760,863 and US Pat. No. 2,791,
It is described in the specification of No. 504, etc.

This photopolymerizable photosensitive resin composition contains photopolymerization initiators commonly known in this technical field (for example, benzoin derivatives such as benzoin methyl ether, benzophenone derivatives such as benzophenone, thioxanthone derivatives, anthraquinone derivatives, acridone derivatives, etc.). ) is added.

3) Photosensitive composition containing a diazo compound The diazo compound in this photosensitive composition is, for example, a diazo resin preferably represented by a condensate of an aromatic diazonium salt and formaldehyde or acetaldehyde. Particularly preferably, a salt of a condensate of p-diazophenylamine and formaldehyde or acetaldehyde,
For example, diazo resin inorganic salts which are reaction products of hexafluoroborophosphate, tetrafluoroborate, perchlorate or periodate with the above condensate, and US Pat. No. 3.300.309. Examples include diazo resin organic salts, which are reaction products of the above condensate and sulfonic acids, as described in . Furthermore, diazo resins are preferably used together with binders. Various polymer compounds can be used as the binding agent, but monomers having an aromatic hydroxyl group such as those described in JP-A-54-98613, such as N- (4-hydroxyphenyl)acrylamide, N-(4-hydroxyphenyl)methacrylamide, O-1@-1 or p-hydroxystyrene, O-1@-1 or p-hydroxyphenyl methacrylate, etc. and other monomers copolymer with U.S. Pat. No. 4. ．． Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as a main repeating unit as described in No. 123,276 Natural resins such as shellac and rosin, polyvinyl alcohol, U.S. Pat. No. 3.75
Polyamide resins such as those described in U.S. Pat. No. 1.257, linear polyurethane resins such as those described in U.S. Pat. Epoxy resins condensed from A and epichlorohydrin, cellulose derivatives such as cellulose acetate and cellulose acetate phthalate are included.

4) Photosensitive composition 0- containing 0-quinonediazide compound
In a photosensitive composition containing a quinonediazide compound,
It is preferable to use the O.quinonediazide compound and the alkali-soluble resin together.

Examples of O.quinonediazide compounds include: Examples include ester compounds of -su7-toquinone diazide sulfonic acid and polycondensation resins of fe, nols, and aldehydes or ketones.

Examples of the phenols include phenol, 0-
Cresol, lightning-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-glucine. 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, m-cresol formaldehyde resin, m-rp mixed cresol formaldehyde resin, resorcinol benzaldehyde resin, pyrogallol acetone resin, and the like.

The condensation rate (reaction rate for one OH group) of 0-naphthoquinonediazide sulfonic acid with respect to Of(group of phenols of the 0-naphthoquinonediazide compound) 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-quinonediazides such as 1,2-benzoquinonediazide sulfonic acid ester, 1,2-naphthoquinonediazide sulfonic acid ester, 1,2-benzoquinonediazide sulfonic acid amide, and 1,2-naphthoquinonediazide sulfonic acid amide. compounds, more specifically J. Kossar.
ar) “Light Sensitive System J” (“Lfh
339th
〜゛352 pages (1965), John Wiley & Sons
) company in New York) and double varnish day 7 orest (W, S, De F.

``Photoresist'' (rest)
1,2-benzoquinonediazide-4-sulfonic acid phenyl ester, 1.2. 1'2'-di(benzoquinonediazide-4-sulfonyl)・dihydroxybiphenyl, l,2-benzoquinonediazide-4・(N
-ethyroot β-su7tyl)-sulfonamide, 1.2
-su7toquinonediazide 5-sulfonic acid cyclohexyl ester, 1-(1,2・naphthoquinonediazide-5
-sulfonyl)-3,5-dimethylpyrazole, 1.2
-su7toquinonediazide 5・sulfonic acid・4′・hydroxydiphenyl-4′-azo-β-su7toll ester, N,N-di(l,2-su7toquinonediazide 5
・Sulfonyl)-aniline, 2′・(l,2-naphthoquinonediazide-5-sulfonyloxy)・l-hydroxy-anthraquinone゛, 1.2・7toquinonediazide 5-sulfonic acid-2゜4・dihydroxybenzophenone ester, l,2-naphthoquinonediazide-5-sulfoneff2-2.3.4-trihydroxybenzophenone ester, 1,2-naphthoquinonediazide-5-
Condensate of 2 moles of sulfonic acid chloride and 1 mole of 4,4'-diaminobenzophenone, 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of 4,4'-dihydroxy-1,1'-diphenylsulfone A condensate of 1 mol of 1,2-7toquinonediazide 5-sulfonic acid chloride and 1 mol of purpurogalin, 1,2.
Examples include 1,2-quinonediazide compounds such as 7-toquinonediazide and 5-(N-dihydroabiethyl)-sulfonamide. Also, special public service 37/1953
No. 37-3627, No. 37-13109, No. 4
No. 0-26126, No. 40-3801, No. 45/56
No. 04, No. 45-27345, No. 51-13013, JP-A No. 48-96575, No. 48-63802,
Also included are l,2-quinonediazide compounds described in Patent Publications No. 48/63803.

Among the above-mentioned 0-quinonediazide compounds, -Quinone diazide 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 0-quinonediazide compound used in the present invention in the photosensitive composition is preferably 5 to 641%, particularly preferably 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 novolac resin used in the present invention include phenol-formaldehyde resin, cresol-formaldehyde resin, phenol-cresol-formaldehyde copolycondensate resin as described in JP-A No. 55-57841, and JP-A-55-57841. Examples include copolycondensate resins of p-substituted phenol and phenol or cresol and formaldehyde as described in Japanese Patent Publication No. 127553/1982.

The molecular weight (polystyrene standard) of the novolak resin is:
Preferably, the number average molecular weight Mn is 3.00X 10” to 7
．． 50X 10', weight average molecular weight My is 1.00X
10' to 3.00X 10', more preferably Mn is 5
．． 00X 10"~4.00XlO', My is 3.OO
There are x 103 to 2.00x 104 te.

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

Photosensitivity I of the present invention of the above-mentioned Novocook sin! The proportion of the first fruits is 5 to 95! is the amount%.

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

General formula (I) General formula [■] (CR+ R! CRs) COO(A %B-OH General formula (Ill) General formula [■] WaH General formula (V) In the formula, R and R6 are each hydrogen It represents an atom, an alkyl group or a carboxyl group, preferably a hydrogen atom.

R3 represents a hydrogen atom, a halogen atom or an alkyl group,
Preferred is a hydrogen atom or an alkyl group such as a methyl group or an ethyl group. R1 represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, preferably a hydrogen atom.

A represents an alkylene group that may have a substituent and connects a nitrogen atom or an oxygen atom with an aromatic carbon atom, and ■ is 0
represents an integer of ~10, and B represents a phenylene group that may have a substituent or a 7-tyrene group that may have a substituent.

The polymer used in the photosensitive composition of the present invention preferably has a copolymer-type structure, and is preferably of the general formula (I
) to [v], which can be used in combination with the structural principles respectively, include, for example, ethylene,
Ethylenically unsaturated olefins such as propylene, imbutylene, butadiene, isoprene, etc., such as styrene, α
- Styrenes such as methylstyrene, p-methylstyrene and p-chlorostyrene; acrylic acids such as acrylic acid and methacrylic acid; e.g. itaconic acid and maleic acid;
Unsaturated aliphatic dicarboxylic acids such as maleic anhydride, such as methyl acrylate, ethyl acrylate, acrylic acid n
-butyl, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate,
a-Gumethylene aliphatic monocarboxylic esters such as methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, ethacrylic acid, and ethyl; nitrites such as acrylonitrile and methacrylonitrile; amides such as acrylamide; Anilides such as anilide, p-chloroacrylanilide, I-nitroacrylanilide, -methoxyacrylanilide, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, such as methyl vinyl ether, ethyl vinyl ether, Vinyl ethers such as isobutyl vinyl ether and β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, such as l-methylthomethoxyethylene, 1.1-dimethoxyethylene, 1.2-
Ethylene derivatives such as dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-nitroethylene, such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinylvirolne, N-vinylviny There are vinyl monomers such as N-vinyl compounds such as lydone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, aliphatic monocarboxylic acid esters and nitriles exhibit excellent performance for the purpose of the present invention and are therefore preferred.

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.

A printout material can be added to the photosensitive composition that causes the formation of a visible image upon exposure to light. The printout material is composed of a compound that generates an acid or a free radical when exposed to light, and an organic dye that changes its color tone by interacting with the compound. 50-36
0-Naphthoquinonediazide-4- described in Publication No. 209
Sulfonic acid halogenides, trihalomethyl-2-avian and trihalomethyl-triazine described in JP-A No. 53-36223 and trihalomethyl-triazine, are described in JP-A-55-6244. - an ester compound or amide compound of naphthoquinone diazide-4-sulfonic acid chloride and a phenol having an electron-withdrawing substituent, or anilic acid;
JP-A-55-77742, JP-A-59-148784
Examples include halomethylvinyloxadiazole compounds and diazonium salts described in No.

Examples of the organic dyes include Victoria Pure Blue BO) (manufactured by Hodogaya Chemical Co., Ltd.), Patent Pure Blue (manufactured by Sumitomo Mikuni Chemical Co., Ltd.), and Oil Blue #6.
03 (manufactured by Orient Kagaku Kogyo Co., Ltd.), Sudan Blue T [ (manufactured by BASE), crystal violet, malachite green, Tsukusin, methyl violet, ethyl violet, methyl orange, brilliant green, fungolet, eosin, rhodamine 6G, etc. Can be done. In addition to the above materials, the photosensitive composition can be used as needed! IJ agents, surfactants, organic acids, acid anhydrides, etc. can be added.

Furthermore, in order to improve the oil sensitivity of the photosensitive composition, the photosensitive composition may contain, for example, p-tert-butylphenol formaldehyde resin, p-n-octylphenol formaldehyde resin, or 0-quinonediazide compound. It is also possible to add partially esterified resins and the like.

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

Examples of solvents that can be used to dissolve each component of the photosensitive composition of the present invention include methyl selonlube, methyl cellosolve acetate, ethyl cellosolve, methyl cellosolve acetate, diethylene glycol 7-methyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, Diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethyl glycol monoisoprobyl dimonthyl,
Propylene glycol, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, cyclopylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, ethyl formate,
Propyl formate, butylacetate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, dimethylformamide, dimethyl sulfoxide, dioxane, acetone, methyl ethyl ketone, cyclohexanone , methylcyclohexanone, diacetone alcohol, acetylacetone, γ-butyrolactone, and the like.

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

The coating method used in coating the surface of the support with the photosensitive composition used in the present invention includes conventionally known methods, such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, and blade coating. And curtain 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,
Conventional methods can be applied, such as exposing a transparent original image having a line image, halftone image, etc. in close contact with the photosensitive surface, and then using a suitable developer to make the non-image areas photosensitive. By removing the layer a relief image is obtained.

As a light source suitable for exposure, a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, a carbon arc lamp, etc. are used.

The developer used for development is preferably an alkaline aqueous solution, such as an aqueous solution of sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, sodium carbonate, potassium carbonate, etc. There is an aqueous alkaline solution. The concentration of the alkaline aqueous solution at this time varies depending on the photosensitive composition and the type of alkali, but is generally 0.1 to 10! The amount range is appropriate, and a surfactant or an organic solvent such as alcohol may be added to the acid-alkali aqueous solution as required.

〔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 thereof is exceeded.

Examples 1 to 5 Preparation of Support-1 An aluminum plate with a thickness of O-3+aIM (material: 1050.
Tempered H16) was degreased in a 5% caustic soda aqueous solution at 65°C for 1 minute, then washed with water, immersed in a 10% nitric acid aqueous solution at 25°C for 1 minute, neutralized, and then washed with water. This aluminum plate was subjected to electrolytic surface treatment in a 0.3 mol/a MM aqueous solution at 30°C for 30 seconds at an alternating current density of 50 A/dta;
Performs a 0 second desmut process. Thereafter, an anodic acid treatment was performed using a 20% sulfuric acid solution at a temperature of 20° C., an electric density of 3 A/da'', and a treatment time of 1 minute, followed by hot water sealing treatment for 20 seconds with hot water at 80''C.

The aluminum plate subjected to the above treatment was immersed in a 1% aqueous sodium sulfinate solution at 80° C. for 30 seconds. After washing with water, it was dried at 80°C for 5 minutes.

Preparation of Supports-2, 3, 4, and 5 Supports-2, 3° were prepared in the same manner as Support-1 except that the following aqueous solution was used instead of the 1% sodium sulfinate aqueous solution in the preparation of the support weight. I got 4.5.

Support - 21% potassium sulfinate aqueous solution tt
3 1% calcium sulfinate aqueous solution // 4 1% ammonium sulfinate aqueous solution Apply the photosensitive composition coating solution (1) using a wire bar,
Dry for 2 minutes at °C. The coating film thickness was 2.2 g/Is''. Exposure was performed using a 2 kW metal halide lamp at 8 mL/am'' for 60 seconds. For development, a 5-fold dilution of commercially available developer 5DR-1 (manufactured by Konica Corporation) was used.
A lithographic printing plate sample i-+ was obtained using a development time of 30 seconds and a development temperature of 25°C.

(Photosensitive composition coating liquid (1) composition) Novolak resin *A 6.7go
-Quinonediazide compound *B 1.5g Surfactant *CO, 2g Victoria Pure Blue BO)] (manufactured by Toko Tsuchigaya Chemical Co., Ltd.) 0.08g
Compound that generates halogen free radicals *D O, 15g5g
Methyl cellosolve 100 ■ Q Preparation of photosensitive lithographic printing plate samples I-2, 3, 4, and 5 Supports -2, 3, 4, and 5 were used in place of support -1; Photosensitive lithographic printing plate samples I-2, 3, 4, and 5 were prepared in the same manner as lithographic printing plate sample 1-1.

These samples were exposed and developed in the same manner as in the case of photosensitive planographic printing plate 1-1, and planographic printing plate sample 1-2.3 was prepared.
, 4.5 was obtained.

Comparative Example 1.2 Preparation of Supports-6 and 7 The following aqueous solution was used instead of the 1% sodium sulfinate aqueous solution in the preparation of Support-1.
Supports 6 and 7 were obtained in the same manner as described above.

Support - 61% sodium sulfate aqueous solution Support - 71% barium acetate aqueous solution Preparation of photosensitive lithographic printing plate samples I-6 and 7. Photosensitive lithographic printing plate samples except that the supports 6 and 7 were used as supports. ! Photosensitive lithographic printing plate samples I-6 and 7 in the same manner as -1.
was created.

These samples were exposed and developed in the same manner as in the case of photosensitive lithographic printing plate sample 1-1 to obtain lithographic printing plate samples r-6 and 7.

Examples 6 to 10 A photosensitive composition coating solution (2) having the following composition was applied onto the support-1.
) was applied with a whirler and dried at 90°C for 1 minute.
. The coating film thickness was 1.7 g/m'. This is designated as photosensitive planographic printing plate sample 11-1.

(Photosensitive composition coating liquid (2) composition) Copolymer *E 5.0g Diazo resin *FO, 5g Jurimer AC-1OL (Nippon Tsumugi Co., Ltd. Il) 0.0
5 g Victoria Pure Blue BOH (manufactured by Toko Tsuchigaya Kagaku Co., Ltd.) 0.1 g Methyl Cellosolve 100 ■α This sample was exposed to light at 8 W/am for 60 seconds using a 2 kW Metal No. 1 Ride lamp, and then developed. Using a 6-fold dilution of commercially available developer 5DN-21 (manufactured by Konica Corp.), development was carried out at a development time of 20 seconds and a development temperature of 27°C to obtain a lithographic printing plate sample n-i.

Preparation of photosensitive lithographic printing plate samples ll-2, 3, 4, 5 The photosensitive composition coating solution (2) was applied onto the supports -2, 3, 4, 5 as photosensitive lithographic printing plate samples r1-. A photosensitive lithographic printing plate sample ■-2°3.4.5 was prepared by coating in the same manner as in 1.

These samples were exposed and developed in the same manner as photosensitive lithographic printing plate sample 1 to obtain lithographic printing plate samples 2, 3, 4, and 5.

Comparative Example 3.4 The photosensitive composition coating liquid (2
) was applied in the same manner as the photosensitive lithographic printing plate sample n-t,
Photosensitive lithographic printing plate samples n-6 and 7 were prepared.

Regarding these samples, the photosensitive lithographic printing plate sample n-
Lithographic printing plate sample I [-6
,7 was obtained.

*A Novolak resin A copolycondensation resin of phenol, 1-cresol, p-cresol, and formaldehyde (the molar ratio of each of phenol, ■-cresol, and p-cresol is 2.0:
4.8: 3.2, My-6500SMy/Mn=5
．． 4) *Bo-quinonediazide compound n *C surfactant Emulgen 120 (manufactured by Kako Co., Ltd.) Polyoxyethylene lauryl ether *D Compound that generates halogen free radicals 2-trichloromethyl-5-(p-methoxystyryl)- 1,3,4-
Oxadiazole (compound described in Example 1 of JP-A-54-74728) *E Copolymer p-hydroxyphenylmethacrylamide/acrylonitrile/ethyl acrylate/methacrylic acid-10/
Copolymer with a composition of 30/60/6 Mv = 60000 *F Diazo resin evaluation method Stain test due to residual fat 5 (5
An image area of m1lX 15c+m) is formed. The image area was erased using an erasing liquid (SIR-15, manufactured by Konica Corp.). The erasing time is divided into five levels (shown in Table 1), and the fringe stains caused by erasing at that time are treated with developing ink (SPO-1).
This was confirmed using a plate (manufactured by Konica Corporation).

O: Good △: Erased marks appear (the ink does not adhere, but the residual film is clearly visible).

X: Smudged (ink adheres to the surface).

Processing Chemical Resistance After plate making under the above exposure and development conditions, ink for development ink (SPO-1 manufactured by Konica Co., Ltd., Pl.
(manufactured by Fuji Photo Film Co., Ltd.) and a plate cleaner (manufactured by UPCA ABC Chemical Company) J used during printing were immersed for a certain period of time, and the condition of the photosensitive layer on the plate at that time was evaluated.

O: No change.

Δ: The surface of the bed is eroded.

×: The base part peels off.

Halftone dot reproducibility The Ni-ni-plate printing plate obtained by the above method was injected with coated paper printing ink (Ni-ni-bright red manufactured by Toyo Ink Manufacturing Co., Ltd.) and soaking water (S) in a printing machine (Heidel GTO).
Printing was performed using EU-3.2.5% (manufactured by Konica Corporation). # of the halftone image of the printed matter with a 25@ loupe
Evaluate the halftone reproduction of the area (#I! point area ratio 97%).
.

0: Reproduction (no entanglement).

×　; Does not reproduce (entanglement occurs).

Printing Durability Printing under the above conditions I: Printing is continued until poor ink adhesion appears in the solid area of the image area of the printed matter or until the ink adheres to the non-image area, and the number of prints is counted at that time.

From the experimental results shown in the table above, it can be seen that the photosensitive lithographic printing plates according to the present invention are superior in both staining due to residual film from development processing and printing durability compared to those made by the conventional technology.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a photosensitive lithographic printing plate which is excellent in both the occurrence of stains due to residual film and printing durability.

Claims (1)

[Scope of Claims] 1) A photosensitive lithographic printing plate, characterized in that the surface of a pretreated support is treated with an aqueous solution containing sulfinic acid or a sulfinate salt, and then a photosensitive layer is provided on the surface. 2) The photosensitive lithographic printing plate according to claim 1, wherein the sulfinate is a metal salt or an ammonium salt.