JPH11115338A - Photo-sensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the erasability of the photo-sensitive layer in a correction process after an image-developing process, and also, make a non-image part hard to stain in printing by a method wherein an aluminum supporting body which is treated with a solution containing a periodic table group VIII transition element metallic salt of an aliphatic monocarboxylic acid at a specified tempera ture, after an anode oxide film is formed, is used. SOLUTION: By an anode oxidation process, an anode oxide film is formed on an aluminum plate or an aluminum alloy plate. Then, this plate or the alloy plate is treated with a solution containing a periodic table group VIII transition element metallic salt of an aliphatic monocarboxylic acid at 30-60 deg.C, and is used as an aluminum supporting body. By performing this treatment, a photo-sensitive lithographic printing plate wherein the surface area per unit geometrical area of a non-image part after an image-developing process, is 5-50 m<2> /m<2> , and a contact angle of a water drop in oil becomes 50 deg. or less, can be obtained. By using such a photo-sensitive lithographic printing plate, the erasability of the photo-sensitive layer is improved, and also, the non-image part becomes hard to contaminate at the time of printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate. More specifically, the present invention relates to a photosensitive lithographic printing plate excellent in erasability after development processing and in which a non-image portion is hardly stained during printing.

[0002]

2. Description of the Related Art Conventionally, a lithographic printing plate is obtained by developing a photosensitive lithographic printing plate obtained by coating a photosensitive composition in a thin layer on an aluminum support after image exposure. The aluminum support is subjected to a surface roughening treatment such as a mechanical method such as a brush grain method or a ball grain method, an electrochemical method such as an electrolytic grain method, or a method combining the both, in general. It is made into a satin shape, then etched with an aqueous solution of an acid or an alkali, and further subjected to an anodizing treatment, and then subjected to a hydrophilizing treatment as required. A photosensitive layer made of a photosensitive composition is provided on the support to form a photosensitive lithographic printing plate (so-called PS plate). As the photosensitive composition, those comprising an o-quinonediazide compound are widely used, and such a photosensitive substance is used alone or mixed with an alkali-soluble resin such as a novolak type phenol resin or a cresol resin, and coated on a support. Is established. When a support having a hydrophilic surface is used, the exposed portion is decomposed by the o-quinonediazide compound,
As it changes to alkali soluble, it is easily removed with an alkaline developer to expose the hydrophilic surface of the support, which receives water and repels the ink. On the other hand, unexposed portions remaining as images are lipophilic and accept ink. This P
The S plate is usually subjected to image exposure, development, correction and gumming steps to form a lithographic printing plate, which is mounted on a printing press for printing.

[0003] During the plate making process of a photosensitive lithographic printing plate, generally, a step of providing a photosensitive layer on an aluminum support obtained by subjecting the surface of a plate of aluminum or its alloy to anodizing treatment, etc .; After the image exposure through the film, the developing step of dissolving and removing the exposed portion of the photosensitive layer with a developing solution, and after the developing step, the edge portion of the original film or the attached dust causes insufficient exposure, resulting in anodizing treatment. And removing the photosensitive layer, which should remain on the aluminum support, which should be removed, with an erasing liquid. In this correction process, the length of time required for the photosensitive layer to be erased to be dissolved and erased with the erasing liquid is called erasability. If the erasure is performed in a short time, the erasability is excellent. It is described as poor erasability. If the erasability can be improved, the repair work can be completed in a short time, leading to an increase in work efficiency.

As a method for improving the erasability in the above-mentioned general correcting step, conventionally, a sealing treatment of the anodic oxide film of the support with hot water or steam or a treatment of the anodic oxide film of the support with nitrite (Japanese Patent Application Laid-open No. No. -108989), treatment with an inclusion compound (Japanese Patent Application Laid-Open No. 8-106157) and the like are known. However, in these conventional erasability improving methods,
The non-image area after the removal of the positive photosensitive layer is liable to be stained. In particular, when the developing solution used in the developing step is reused, the non-image area is significantly stained.
On the other hand, Japanese Patent Publication No. Hei 7-90669 discloses that a metal salt of an aliphatic monocarboxylic acid is used to improve the adhesion to a photosensitive layer by forming a fine structure on the surface of an anodic oxide film. A process for producing a lithographic printing plate support, wherein the process is performed at a high temperature of up to 95 ° C. for 1 to 2 minutes is described. A lithographic printing plate using a support that has been subjected to such treatment has improved erasability, but has significant stains on the non-image area during printing.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive lithographic printing plate which is excellent in erasability of a photosensitive layer in a repairing step after a developing process and in which a non-image portion is hardly stained during printing. .

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object. As a result, after forming an anodized film on an aluminum plate or an aluminum alloy plate by anodizing treatment, the temperature was lowered to 30 to 60 ° C. It has been found that the above object can be achieved by a photosensitive lithographic printing plate characterized by using an aluminum support treated with an aqueous solution containing a metal salt of a transition element group VIII of the periodic table of an aliphatic monocarboxylic acid. It was done. Further, by performing the above process, the surface area per unit geometric area of the non-image portion after development treatment is 5 to 50 m ² / m ^2, and equal to or less than the contact angle 50 ° of the water-in-oil photosensitive lithographic printing A plate can be obtained, and by using such a photosensitive lithographic printing plate, the erasability of the photosensitive layer is improved, and the non-image portion is less likely to be stained during printing.

In the photosensitive lithographic printing plate according to the present invention,
The following can be considered as reasons why the erasability of the photosensitive layer is sufficiently improved and the easiness of staining of the non-image area is also improved.
That is, the micropores present in the anodic oxide film on the aluminum support are appropriately sealed by the transition metal salt of the group VIII of the aliphatic monocarboxylic acid, whereby the penetration of the photosensitive layer is suppressed, and erasure is performed. The dissolution and removal of the photosensitive layer by the liquid are promoted, and the erasability is improved. In addition, a general well-known sealing process has a disadvantage that a fine structure is formed on the outermost surface of the aluminum support, and the non-image portion is easily stained due to this. However, according to the processing method of the present invention, The formation of such a fine structure on the outermost surface of the support is suppressed, and as a result, the contact angle of the water-in-oil droplet in the non-image area after development is 50 °.
As a result, the easiness of contamination during printing is improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Treatment with Metal Salt of Aliphatic Monocarboxylic Acid] The aluminum substrate subjected to the treatment described below is immersed in an aqueous solution of a transition metal salt of a Group VIII metal in the periodic table at 30 to 60 ° C. Examples of the aliphatic monocarboxylic acid include formic acid, acetic acid, butyric acid, palmitic acid, and stearic acid. Examples of the transition metal of Group VIII of the periodic table include one or more metals selected from the group consisting of Co, Ni, and Fe. As the transition metal salt of the group VIII of the aliphatic monocarboxylic acid, nickel acetate and cobalt acetate are particularly desirable. The concentration of the aqueous solution of the transition metal salt of the group VIII of the aliphatic monocarboxylic acid is from 0.01 to 0.50 mol / l, preferably from 0.02 to 0.30 mol / l. The treatment time with the aqueous solution is 1 to 100 seconds, preferably 5 to 30 seconds.
The processing temperature is 30 to 60C, preferably 30 to 50C. After the treatment, wash with running water and air dry. Since this treatment is a treatment in which ions and molecules in the liquid migrate into the micropores of the anodic oxide film by immersion and are sealed by being adsorbed, a shorter time, lower concentration, Under low-temperature processing conditions, adsorption is insufficient, sufficient sealing does not occur, and erasability is not improved. On the other hand, under the processing conditions of longer time, higher concentration, and higher temperature compared to the above conditions, adsorption proceeds excessively and sufficient pores are formed, but a fine structure is further formed on the surface of the micropores, resulting in contamination during printing. cause. A photosensitive layer can be directly provided on the aluminum substrate that has been subjected to the above-described treatment. However, if necessary, a hydrophilic undercoat layer may be provided, and then the photosensitive layer may be provided.

[Aluminum support] As the aluminum support used in the photosensitive lithographic printing plate of the present invention, a substrate obtained by subjecting a substrate such as an aluminum plate to a surface treatment is used. Examples of such a substrate include a pure aluminum plate made of aluminum, an aluminum alloy plate containing aluminum as a main component and containing a trace amount of a different element, or a plastic film or paper on which aluminum or an aluminum alloy is laminated or vapor-deposited. Further, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in JP-B-48-18327 may be used. In the following description, the above-mentioned substrates made of aluminum or an aluminum alloy are collectively used as aluminum substrates. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc,
There are bismuth, nickel, titanium and the like, and the content of the foreign element in the alloy is 10% by weight or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. Thus, the composition of the aluminum plate applied to the present invention is not specified,
Conventionally known and publicly used materials, for example, JIS A 1050,
JIS A 1100, JIS A 3103, JIS A 3005, etc. can be used as appropriate. The thickness of the aluminum substrate used in the present invention is about 0.1 mm to 0.6 mm. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's request. The aluminum substrate is appropriately subjected to a substrate surface treatment described below.

[Graining treatment] Examples of the method of graining the aluminum substrate include mechanical graining, chemical etching, and electrolytic graining as disclosed in JP-A-56-28893. Further, an electrochemical graining method for electrochemically graining in a hydrochloric acid or nitric acid electrolyte, a wire brush graining method for scratching the aluminum substrate surface with a metal wire, and a ball graining method for graining the aluminum surface with a polishing ball and an abrasive. Alternatively, a mechanical graining method such as a brush grain method in which the surface is grained with a nylon brush and an abrasive may be used. The above graining methods can be used alone or in combination. The graining method for producing a desired surface roughness in the present invention is an electrochemical method of chemically graining in a hydrochloric acid or nitric acid electrolyte. In the electrochemical graining method, a suitable current density is 100
In the range of ^{C / dm 2 ~400C / dm 2} . More specifically, in an electrolytic solution containing 0.1 to 50% hydrochloric acid or nitric acid,
Temperature 20-100 ° C, time 1 second-30 minutes, current density 10
It is preferred to carry out the electrolysis under conditions of ^{0C / dm 2 ~400C / dm 2} .

The grained aluminum substrate is etched by acid or alkali chemicals.
When an acid is used as an etching agent, it takes time to destroy a fine structure, which is disadvantageous in industrially applying the present invention. However, it can be improved by using an alkali as an etching agent. Alkali etching agents preferably used in the present invention include sodium hydroxide, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like.
The preferred ranges of the concentration and the temperature of these etching agents are 1 to 50% and 20 to 100 ° C., respectively, and the conditions are preferably such that the amount of Al dissolved is 5/20 g / m ³ . After the etching, pickling is performed to remove dirt (smut) remaining on the surface. The acids used are nitric acid, sulfuric acid,
Phosphoric acid, chromic acid, hydrofluoric acid, borofluoric acid and the like are used. In particular, as a method for removing the smut after the electrochemical graining treatment, a method for removing the smut from a temperature of 50 to 90 ° C. as described in JP-A-53-12739 can be used.
To contact with sulfuric acid of about 65% by weight
The alkali etching method described in JP-A-28123 is preferred.

[Anodizing treatment] The aluminum substrate treated as described above is further subjected to anodizing treatment. The anodizing treatment can be performed by a method conventionally performed in this field. Specifically, sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc., or a combination of two or more of these, and flowing a direct current or alternating current to aluminum in an aqueous solution or non-aqueous solution, the aluminum support An anodic oxide film is formed on the surface. The conditions of the anodizing treatment vary depending on the electrolytic solution used, and thus cannot be unconditionally determined. However, in general, the concentration of the electrolytic solution is 1 to 80%, the liquid temperature is 5 to 70 ° C.,
The appropriate range is 0.5 to 60 amps / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 to 100 seconds.

Among these anodizing treatments, in particular, a method for anodizing at a high current density in sulfuric acid and a method disclosed in US Pat. No. 3,5,768 described in GB 1,412,768.
An anodic oxidation method using phosphoric acid as an electrolytic bath described in Japanese Patent No. 11,661 is preferable. In the present invention,
The anodic oxide film preferably has a thickness of 1 to 10 g / m ² ,
When the amount is 1 g / m ² or less, the plate is easily scratched and 10 g / m ²
The above requires a large amount of power for manufacturing, which is economically disadvantageous. Preferably, it is 1.5 to 7 g / m ² , more preferably ² to 5 g / m ² .

[Alkali Metal Silicate Treatment] The anodic oxide film of the aluminum substrate treated as described above may be treated with an aqueous solution of an alkali metal silicate as necessary. For example, the anodic oxide film of the aluminum substrate treated as described above is converted into an aqueous solution containing 1 to 30% by weight, preferably 2 to 15% by weight of an alkali metal silicate and having a pH of 10 to 13 at 25 ° C. 0.5 for example at 50-90 ° C.
Immerse for ４０40 seconds, more preferably for 1-20 seconds. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution will gel, and if it is higher than 13, the oxide film will be dissolved. As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used,
Among them, sodium silicate and potassium silicate are preferable. Hydroxides used to raise the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide,
There are lithium hydroxide and the like, and preferably, sodium hydroxide and potassium hydroxide are used. In addition, an alkaline earth metal salt or a Group IVB metal salt may be added to the above-mentioned processing solution. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate and barium nitrate, and aqueous solutions of sulfates, hydrochlorides, phosphates, acetates, oxalates, borates and the like. IVB
Group IV metal salts include titanium tetrachloride, titanium trichloride, potassium titanium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride,
And the like. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more.

[Hydrophilic undercoat layer] A preferred hydrophilic undercoat layer used in the present invention is described in JP-A-60-1494.
No. 91, comprising a compound having at least one amino group and at least one group selected from the group consisting of a carboxyl group and a salt group thereof, and a sulfo group and a salt group thereof. Hydrophilic layer, JP-A-60-23
A hydrophilic layer comprising a compound selected from a compound having at least one amino group and at least one hydroxyl group and a salt thereof disclosed in Japanese Patent Application Laid-Open No. Sho.
No. 19494, a hydrophilic layer containing a phosphate, and a polymer compound containing at least one monomer unit having a sulfo group disclosed in JP-A-59-101651 as a repeating unit in the molecule A hydrophilic layer, which is disclosed in JP-A-4-282637.
A substituted or unsubstituted aliphatic or aromatic compound represented by R ¹ (PO (OH) ₂ ) _n or R ^1- (PO (OH) (R ² )) _n (n
Is 1 or 2, and when n = 1, R ¹ and R ² represent a substituted or unsubstituted alkyl group, alkoxy group, aryloxy group, aryl group, acyl group, acyloxy group, and n =
2, R ¹ represents a substituted or unsubstituted alkylene group or an arylene group, and R ² has the same meaning as defined above), and an organic layer containing at least one compound selected from the group consisting of It is.

[Photosensitive layer] As the composition of the photosensitive layer used in the present invention, any composition can be used as long as its solubility or swelling property in a developing solution before and after exposure changes. Hereinafter, representative ones will be described. (A) Photosensitive layer composed of o-quinonediazide compound Examples of the photosensitive compound of the positive photosensitive composition include o-quinonediazide compounds, and representative examples thereof include o-naphthoquinonediazide compounds. As the o-naphthoquinonediazide compound, a compound which is an esterification of 1,2-diazonaphthoquinonesulfonic acid chloride and pyrogallol-acetone resin described in JP-B-43-28403 is preferable. Other suitable o-quinonediazide compounds include those described in U.S. Patent Nos. 3,046,120 and 3,188,210.
There are esters of 2-diazonaphthoquinone sulfonic acid chloride with phenol-formaldehyde resin. Other useful o-naphthoquinonediazide compounds include those reported and known in numerous patents. For example, JP-A-47-5303 and JP-A-48-63
No. 802, No. 48-63803, No. 48-96575
Nos. 49-38701, 48-13354, JP-B-37-18015, 41-11222, and 4
Nos. 5-9610, 49-17481, U.S. Pat. Nos. 2,797,213, 3,454,400, and 3,5
No. 44,323, No. 3,573,917, No. 3,674,4
No. 95, No. 3,785,825, British Patent No. 1,227,6
No. 02, No. 1,251,345, No. 1,267,005
No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

An o-naphthoquinonediazide compound obtained by reacting a polyhydroxy compound having a molecular weight of 1,000 or less with 1,2-diazonaphthoquinonesulfonic acid chloride can also be used. Specific examples of such compounds are described in JP-A-51-139402 and JP-A-58-15094.
No. 8, No. 58-203434, No. 59-165053
No., No. 60-112445, No. 60-134235
No., No. 60-163443, No. 61-118744
Nos. 62-10645, 62-10646, 62-153950, 62-178562, and 6
4-76047; U.S. Pat. No. 3,102,809;
No. 3,126,281, No. 3,130,047, No. 3,14
No. 8,983, No. 3,184,310, No. 3,188,21
No. 0, No. 4,639,406 and the like, and those described in each gazette or specification. These o-
When synthesizing the naphthoquinonediazide compound, it is preferable to react 0.2-1.2 equivalents of 1,2-diazonaphthoquinonesulfonic acid chloride with respect to the hydroxy group of the polyhydroxy compound, and 0.3-1.0 equivalents. More preferably, the reaction is performed. As the 1,2-diazonaphthoquinonesulfonic acid chloride, 1,2-diazonaphthoquinone-5-sulfonic acid chloride is preferable, but 1,2-diazonaphthoquinone-4-sulfonic acid chloride can also be used.

The obtained o-naphthoquinonediazide compound is a mixture of 1,2-diazonaphthoquinonesulfonate groups having various positions and amounts of 1,2-diazonaphthoquinonesulfonate groups. The ratio of the compound converted to the above to the mixture (the content of the completely esterified compound) is preferably 5 mol% or more, more preferably 20 to 99 mol%. Further, as a photosensitive compound which acts positively without using an o-naphthoquinonediazide compound, for example, a polymer compound having an o-nitrocarbinol ester group described in JP-B-56-2696 is also used in the present invention. Can be. Further, a compound which generates an acid by photolysis and -CO which dissociates by the acid
A combination system with a compound having a -C- group or a -CO-Si group can also be used in the present invention.

For example, a combination of a compound capable of generating an acid by photolysis with an acetal or an O, N-acetal compound (JP-A-48-90303), a combination with an orthoester or amide acetal compound (JP-A-51-120)
714), a combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133429),
Combination with enol ether compound (JP-A-55-12
No. 995), a combination with an N-acylimino carbon compound (JP-A-55-126236), a combination with a polymer having an orthoester group in the main chain (JP-A-56-173).
No. 45), a combination with a silyl ester compound (JP-A-6
No. 0-10247) and a combination with a silyl ether compound (JP-A-60-37549, JP-A-60-1214).
No. 46). The amount of these positive-acting photosensitive compounds (including the above combinations) in the photosensitive composition of the present invention is suitably from 10 to 50% by weight, more preferably from 15 to 40% by weight. It is.

The o-quinonediazide compound alone can constitute the photosensitive layer, but is preferably used together with a resin soluble in alkaline water as a binder. Such resins soluble in alkaline water include novolak resins having this property, such as phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, and m- / p.
-Mixed cresol formaldehyde resin, phenol /
Cresol (may be m-, p-, or m- / p-mixed) Cresol formaldehyde resin such as mixed formaldehyde resin, phenol-modified xylene resin, polyhydroxystyrene, polyhalogenated hydroxystyrene, JP-A-51-34711 Acrylic resin containing a phenolic hydroxyl group as disclosed in
Various alkali-soluble polymer compounds such as an acrylic resin having a sulfonamide group described in JP-A-2-866 and a urethane-based resin can be contained.
These alkali-soluble polymer compounds have a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 60,
000 is preferred.

Such an alkali-soluble polymer compound is used in an amount of not more than 70% by weight of the total composition. Further, as described in U.S. Pat. No. 4,123,279, phenol having a C3-8 alkyl group as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, and formaldehyde are used. And o-naphthoquinonediazidosulfonic acid esters of these condensates (for example, those described in JP-A-61-243446).
It is preferable to use a combination of these in order to improve the oil sensitivity of the image.

In the photosensitive composition of the present invention, a cyclic acid anhydride for enhancing the sensitivity, a printing-out agent for obtaining a visible image immediately after exposure, a dye or other filler as an image coloring agent, and the like are included. Can be added. Examples of the cyclic acid anhydride include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3,6-endooxy- △ ⁴ -tetrahydroanhydride as described in U.S. Pat. No. 4,115,128. Phthalic acid, tetrachlorophthalic anhydride,
Maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like. By containing these cyclic anhydrides in an amount of 1 to 15% by weight based on the total weight of the composition, the sensitivity can be increased up to about three times. As a printing-out agent for obtaining a visible image immediately after exposure, a combination of a photosensitive compound that releases an acid upon exposure and an organic dye capable of forming a salt can be exemplified.

Specifically, o-type compounds described in JP-A-50-36209 and JP-A-53-8128 are disclosed.
Combinations of naphthoquinonediazide-4-sulfonic acid halide and salt-forming organic dyes and JP-A-53-36223, JP-A-54-74728, JP-A-60-3626, and JP-A-61-1
No. 43748, No. 61-151644, No. 63-58
No. 440, a combination of a trihalomethyl compound and a salt-forming organic dye. Other dyes besides the above-mentioned salt-forming organic dyes can be used as image coloring agents. Suitable dyes, including salt-forming organic dyes, include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 130, Oil Bink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 60
3. Oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Co., Ltd.), Victoria Pure Blue, crystal violet (CI142555), ethyl violet (CI
42600), methyl violet (CI4253)
5), rhodamine B (CI45170B), malachite green (CI42000), methylene blue (CI5
2015). In addition, Japanese Unexamined Patent Publication
The dyes described in JP-293247 are particularly preferred.

In the present invention, the photosensitive composition is dissolved in a solvent capable of dissolving the above-mentioned components, and coated on a support. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, toluene , Ethyl acetate, methyl lactate, ethyl lactate, dimethyl sulfoxide, dimethylacetamide,
Examples include dimethylformamide, water, N-methylpyrrolidone, tetrasdrofluryl alcohol, acetone, diacetone alcohol, methanol, ethanol, isopropanol, diethylene glycol, and dimethyl ether. These solvents are used alone or in combination. The concentration (solid content) of the above components in the solution is 2 to 50.
% By weight. Although the amount of application varies depending on the application, for example, a photosensitive lithographic printing plate generally preferably has a solid content of 0.5 to 3.0 g / m ² . As the amount of coating decreases, the photosensitivity increases, but the physical properties of the photosensitive film deteriorate. In the photosensitive composition of the present invention, a surfactant for improving coating properties, for example, a fluorine-based surfactant as described in JP-A-62-170950 can be added. . The preferred amount is the total amount of the photosensitive composition.
It is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight.

(B) Photosensitive Layer Consisting of Diazo Resin and Binder A negative working photosensitive diazo compound is disclosed in US Pat.
Diphenylamine which is a reaction product of a diazonium salt and an organic condensing agent containing a reactive carbonyl salt such as aldol and acetal disclosed in the specifications of U.S. Pat. Nos. 63,631 and 2,667,415. A condensation product of a p-diazonium salt and formaldehyde (a so-called photosensitive diazo resin) is preferably used. Other useful condensed diazo compounds are described in JP-B-49-48001 and JP-B-49-453.
Nos. 22 and 49-45323. These types of photosensitive diazo compounds are usually obtained in the form of water-soluble inorganic salts and can therefore be applied from aqueous solutions. Further, these water-soluble diazo compounds were prepared by
No. 1167, which reacts with one or more aromatic or aliphatic compounds having one or more phenolic hydroxyl groups, sulfonic acid groups, or both, and obtains a substantially water-insoluble photosensitive product obtained by the reaction. A hydrophilic diazo resin can also be used.

Further, as described in JP-A-56-121031, it can be used as a reaction product with hexafluorophosphate or tetrafluoroborate. Examples of reactants having a phenolic hydroxyl group include hydroxybenzophenone, 4,4-bis (4 '
-Hydroxyphenyl) pentanoic acid, resorcinol,
Or a diphenolic acid such as diresorcinol, which may further have a substituent. Hydroxybenzophenone includes 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,
2'-dihydroxy-4,4'-dimethoxyphenone or
2,2 ', 4,4'-tetrahydroxybenzophenone is included. Preferred sulfonic acids include, for example, aromatic sulfonic acids such as sulfonic acids such as benzene, toluene, xylene, naphthalene, phenol, naphthol and benzophenone, or soluble salts thereof, for example, ammonium and alkali metal salts. The sulfonic acid group-containing compound may be generally substituted with a lower alkyl, a nitro group, a halo group, and / or another sulfonic acid group. Preferred examples of such compounds include benzene sulfonic acid, toluene sulfonic acid, naphthalene sulfonic acid, 2,5-dimethylbenzene sulfonic acid, sodium benzene sulfonate, naphthalene-2-sulfonic acid, 1-naphthol 2 (or 4 ) -Sulfonic acid, 2,4
-Dinitro-1-natol-7-sulfonic acid, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, sodium m- (p'-anilinophenylazo) benzenesulfonic acid, alizarinsulfonic acid, o-toluidine- Examples include m-sulfonic acid and ethanesulfonic acid. Also useful are the sulfonic esters of alcohols and their salts. Such compounds are usually readily available as anionic surfactants. Examples include lauryl sulfate, alkylaryl sulfate, p-
Examples thereof include ammonium salts such as nonylphenyl sulfate, 2-phenylethyl sulfate, and isooctylenoxydiethoxyethyl sulfate, and alkali metals.

These substantially water-insoluble photosensitive diazo resins can be formed as a precipitate by mixing the water-soluble photosensitive diazo resin with the above-mentioned aqueous solution of the aromatic or aliphatic compound in an amount that is preferably substantially equivalent. Isolated. Further, diazo resins described in British Patent No. 1,312,925 are also preferable. A diazo resin containing an oxygen acid group of phosphorus described in JP-A-3-253857, a diazo resin condensed with a carboxyl-containing aldehyde or an acetal compound thereof described in JP-A-4-18559, Further, a diazo resin copolymerized with a carboxy group-containing aromatic compound such as phenoxyacetic acid described in Japanese Patent Application No. 3-23031 is also preferable. The most preferred diazo resin is 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonate, a condensate of p-diazophenylamine and formaldehyde. The content of the diazo resin is suitably from 5 to 50% by weight in the photosensitive layer. When the amount of the diazo resin decreases, the photosensitivity naturally increases, but the stability with time decreases. The optimal amount of diazo resin is about 8-20% by weight.

On the other hand, various polymer compounds can be used as the binder. In the present invention, those containing groups such as hydroxy, amino, carboxylic acid, amide, sulfonamide, active methylene, thioalcohol, epoxy and the like are used. Is desirable. Such preferred binders include shellac, described in GB 1,350,521, GB 1,460,973 and US Pat.
Polymers containing hydroxyethyl acrylate units or hydroxyethyl methacrylate units as the main repeating units, as described in US Pat. No. 23,276, polyamides described in US Pat. No. 3,751,257 Resins, phenolic resins described in GB 1,074,392 and polyvinyl acetal resins such as polyvinyl formal resin, polyvinyl butyral resin, U.S. Pat. No. 3,660,097. Linear polyurethane resin, phthalated resin of polyvinyl alcohol, epoxy resin condensed from bisphenol A and epichlorohydrin, polymers containing amino groups such as polyaminosulfone and polyalkylamino (meth) acrylate, cellulose acetate,
Cellulose derivatives such as cellulose alkyl ether and cellulose acetate phthalate are included. Compositions comprising a diazo resin and a binder include British Patent 1,0
Additives such as pH indicators as described in U.S. Pat. No. 41,463, phosphoric acid, dyes and the like described in U.S. Pat. No. 3,236,646 can be added.

(C) Photosensitive layer comprising azide compound and binder (high molecular compound) For example, British Patent Nos. 1,235,281 and 1,495,86
No. 1 and JP-A-51-32331, 51
JP-A-50-5102, JP-A-50-84302, a composition comprising an azide compound and a water-soluble or alkali-soluble polymer compound described in JP-A-36128 and the like.
A composition comprising a polymer containing an azide group and a polymer compound as a binder described in JP-A Nos. 50-84303 and 53-12984 is included.

(D) Other photosensitive resin layers For example, polyester compounds disclosed in JP-A-52-96696, British Patent No. 1,112,277,
No. 1,313,390, No. 1,341,004, No. 1,
Polyvinyl cinnamate-based resins described in each specification such as 377,747, U.S. Pat.
Photopolymerizable photopolymer compositions described in JP-A-072,527 and JP-A-2-244050, and a silver-triggered polymerization composition described in JP-A-7-28248 are included.

(E) Electrophotographic photosensitive layer The electrophotographic photosensitive layer is mainly composed of a photoconductive compound and a binder. For the purpose of improving sensitivity, obtaining a desired photosensitive wavelength range, etc., a known electrophotographic photosensitive layer may be used. Pigments, dyes, chemical sensitizers, other additives and the like can be used. The photosensitive layer can be composed of a single layer or a plurality of layers having separate functions of charge generation and charge transport. The lithographic printing plate can be obtained by forming a toner image on a photosensitive layer by a known electrophotographic process, using the toner image as a resist layer, and decoding a non-image portion. Such a photosensitive layer is described, for example, in JP-B-37-17162 and JP-B-38-6.
No. 961, JP-A-56-107246, and JP-A-60-25
No. 4142, JP-B-59-36259, and 59-25
No. 217, JP-A-56-146145, JP-A-62-19
No. 4257, No. 57-147656, No. 58-100
Nos. 862, 57-161863, and many other publications, all of which can be suitably used.

The thickness of the photosensitive layer may be 0.1 to 30 μm, more preferably 0.5 to 10 μm. The amount of the photosensitive layer provided on the support (fixed frequency) from about 0.1 to about 7 g / m ^2, preferably in the range of 0.5-4 g / m ^2. The surface of the photosensitive layer provided as described above is preferably matted in order to shorten the time for evacuation during contact exposure using a vacuum printing frame and to prevent printing blur. Specifically, JP-A-50-125805 and JP-B-57-65
Nos. 82 and 61-28986, a method of providing a mat layer as described in JP-B-62-6233.
No. 7, a method of heat-fusing a solid powder, and the like. After the imagewise exposure of the photosensitive lithographic printing plate of the present invention, the lithographic printing plate is made into a lithographic printing plate by a process including development by a conventional method. For example, in the case of a positive type lithographic printing plate having a photosensitive layer (A), after image exposure, U.S. Pat.
By developing with an aqueous alkali solution as described in JP-A-9,434 and JP-A-3-90388, the photosensitive layer on the exposed portion is removed, and a lithographic printing plate is obtained. In the case of a negative type lithographic printing plate having a photosensitive layer (B) composed of a diazo resin and a binder, after image exposure, the plate is developed with a developing solution as described in, for example, US Pat. No. 4,186,006. As a result, the unexposed portion of the photosensitive layer is removed to obtain a lithographic printing plate.

The photosensitive lithographic printing plate of the present invention is disclosed in
JP-A-8002, JP-A-55-115045 and JP-A-59-15045.
It goes without saying that the plate-making process may be performed by the method described in each of the publications of No. 58431. That is, after the development processing,
A desensitization treatment after washing with water, a desensitization treatment as it is, a treatment with an aqueous solution containing an acid, or a treatment with an aqueous solution containing an acid may be followed by a desensitization treatment. Furthermore, in the development process of this type of photosensitive lithographic printing plate, the alkali aqueous solution is consumed depending on the processing amount, and the alkali concentration is reduced, or the alkali concentration is reduced by air due to long-time operation of the automatic developing solution. The processing capacity is reduced. At this time, a fresh unused developer (replenisher) is added, or the processing capacity is increased by using a replenisher having a high alkalinity as described in JP-A-54-62004. May be recovered. In this case, a method of adding a replenisher in an amount proportional to the length of one piece of the PS plate to be processed or US Pat. No. 4,882,2
It is preferable to replenish by the method described in No. 46.

Further, the plate making process as described above is disclosed in
It is preferably carried out using an automatic developing machine as described in JP-A-7054 and JP-A-2-32357. Further, when the photosensitive lithographic printing plate of the present invention is subjected to image exposure, development, washing or rinsing, and then unnecessary image portions are erased, it is described in JP-B-2-13293. It is preferable to use such an erasing liquid. Examples of the desensitized gum which is applied as required in the final step of the plate making process include JP-B-62-16834 and JP-B-62-25118.
No. 63-52600, JP-A-62-7595,
Those described in JP-A-62-11693 and JP-A-62-83194 are preferable. Furthermore, when the photosensitive lithographic printing plate of the present invention is subjected to image exposure, development, washing or rinsing, erasing if desired, and burning after washing with water, before burning, the Japanese Patent Publication No. 61-251 is required.
No. 8, No. 55-28062, JP-A-62-31859.
And JP-A-61-159655. Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

[0035]

[Example] An aluminum plate having a thickness of 0.30 mm was placed on a nylon plate.
Using an aqueous suspension of lashes and 400 mesh pamistone
After graining the surface, it was thoroughly washed with water. 10%
Etch in sodium hydroxide at 70 ° C for 60 seconds
And then washed with running water and washed with 20% HNO_ThreeWith neutralization washing, water
I washed. This is V_A= Alternating sine wave under the condition of 12.7V
260 coulomb /
dm^TwoThe electrolytic surface roughening treatment was performed with the amount of electricity at the time of anode. The table
When the surface roughness was measured, it was 0.55 μ (Ra display).
Was. 30% H_TwoSO_FourImmersion in aqueous solution
After desmutting at 55 ° C for 2 minutes,
H_TwoSO_FourCurrent density 5A / dm in aqueous solution ^TwoFor 45 seconds
Extremely oxidized to produce an aluminum support. Then on
After immersion treatment of the support under the treatment conditions shown in Table 1,
It was washed with water and dried naturally. Next, the following photosensitive solution was
25ml / m by ting^TwoApply and dry at 100 ° C for 1 minute
To obtain positive photosensitive lithographic printing plates of Examples and Comparative Examples.
Was. Application amount after drying is about 1.5 g / m^TwoMet.

[Photosensitive solution] Esterified product of 1,2-diazonaphthoquinone-5-sulfonyl chloride and 0.90 g pyrogallol-acetone resin (described in Example 1 of US Pat. No. 3,635,709) Phenol / p-cresol with weight average molecular weight of 8,000 1.90 g aldehyde resin (phenol / p-cresol molar ratio: 5/5, containing 0.7% of unreacted cresol) -Formaldehyde novolak resin (weight 0.3 g, average molecular weight 1,700, number average molecular weight 600, containing 1% of unreacted cresol)

P-N-octylphenol-formaldehyde resin 0.02 g (as described in US Pat. No. 4,123,279) naphthoquinonediazide-1,2-diazide-4-sulfonic acid 0.01 g chloride tetrahydrochloride Phthalic anhydride 0.02 g Victoria Pure-BOH (manufactured by Hodogaya Chemical Co., Ltd.) 0.05 g Dye Megafac F-176 (manufactured by Dainippon Ink and Chemicals, Inc.) in which the counter anion is changed to 1-naphthalenesulfonic acid .01g Fluorinated surfactant) Methyl ethyl ketone 55 g

Based on the method described in Example 1 of JP-B-61-28986, a mixture of (methyl methacrylate / ethyl acrylate sodium acrylate: 68/20/12) was placed on the plate thus coated. 0.1 g of tartrazine was dissolved in 100 g of the aqueous polymer solution, and this was electrostatically sprayed to form a mat layer. The photosensitive lithographic printing plate thus obtained was used as a light source with a 2KW metal halide lamp (Iwasaki Electric Idol Fin 200
00), and the exposure time was adjusted by a step guide manufactured by Fuji Photo Film Co., Ltd. so as to clear four steps. After the exposure, the planographic image quality of the printing plate was visually evaluated, and a 5.26% aqueous solution (pH = 12.7) of sodium silicate having a molar ratio of SiO ₂ / Na ₂ O of 1.74 was used as a developing solution. FP- manufactured by Fuji Photo Film Co., Ltd.
2W (1: 1) was passed through an automatic processor Stabilon 900D manufactured by Fuji Photo Film Co., Ltd. in which the film was processed. Table 1 shows the results of measuring the contact angle of water-in-oil droplets and the surface area per unit geometric area of the non-image area after development, and the results of evaluating the erasability and the print stain on the obtained sample.

<Measurement method> Contact angle of water-in-oil droplet: The non-image area of the printing plate after development was cut into an appropriate size, and then cut in an organic solvent (Maruzen Petrochemical Sowasol 1000: substance name trimethylbenzene). One minute after carefully inserting the air bubbles so as not to form bubbles, a water drop of pure water is dropped on the printing plate, and 30 seconds after the drop, the contact angle between the printing plate surface and the water droplet is measured. This was repeated three times, and the average value was defined as the contact angle of water-in-oil. Surface area per unit geometrical area: Cut the developed front image area to a size of 50 mm x 60 mm. If gum for protecting the plate surface adheres to the non-image area on the surface, wash it off with tap water and air dry. Then, after degassing at 180 ° C. for 60 minutes in a nitrogen atmosphere using a Cantasorb manufactured by Yuasa Ionics, a surface area was measured at an appropriate sensitivity setting using a helium-krypton mixed gas as an adsorption gas. The measurement was performed twice and the average value was converted per unit geometric area [that is, the measured surface area (m ² ) / (sampling size: 0.
05m × 0.06m)].

Erasability: Time required for dissolving the image portion of the printing plate after development with an erasing solution (erasing solution RP-2 manufactured by Fuji Photo Film Co., Ltd.) until the photosensitive layer appears to be completely removed ( The time until the remaining photosensitive layer in the image area could not be completely discriminated) was measured. Printing stains: Attach the printing plate to the offset printing press, start water supply and paper feeding simultaneously with ink applied to the entire surface of the printing plate, and remove the ink on the printed material corresponding to the non-image area. Finally, the number of damaged sheets until the original non-image area where no ink adheres to the printed matter was used as an index of print stain.

Table 1 Processing conditions 種類 Type of aqueous solution Concentration Temperature Time (° C) (seconds) ───── ─────────────────────── Example 1 Nickel acetate 0.24mol / L 50 10 ──────────────── ──────────── Example 2 Nickel acetate 0.24mol / L 60 10 ─────────────────────────── ─ Example 3 Nickel acetate 0.20mol / L 50 10 ──────────────────────────── Example 4 Cobalt acetate 0.24mol / L 30 10──────────────────────────── Example 5 Cobalt acetate 0.024mol / L 50 10────────── ────────────────── Example 6 Cobalt acetate 0.024 mol / L 30 10 ────────── ────────────────── Comparative Example 1 None None None None ──────────────────────── ──── Comparative Example 2 pure water − 100 30 ──────────────────────────── Comparative Example 3 barium acetate 1.0 wt% 95 60比較 Comparative Example 4 Calcium acetate 2.0 wt% 95 120 ──────────── ────────────────

Table 1 (continued) 水 Water droplet in oil Unit geometric area Contact angle per unit Surface area Erasability Print stain (°) (m ² / m ² ) ──────────────────────────────── Example 1 21 30 20 seconds 18 sheets ──────────────────────────────── Example 2 29 20 10 seconds 21 sheets ─── ───────────────────────────── Example 3 18 35 20 seconds 17 sheets ──────────── ──────────────────── Example 4 29 30 20 seconds 20 sheets ───────────────────── ─────────── Example 5 41 25 20 seconds 25 sheets ────────────────────────────── ── Example 6 20 40 40 seconds 19 sheets ──────────────────────────────── Comparative example 1 20 120 100 seconds 20 sheets ─── ───────────────────────────── Comparative Example 2 70 15 10 seconds 55 sheets ──────────── ──────────────────── Comparative Example 3 85 10 10 seconds 56 sheets ───────────────────── ─────────── Comparative Example 4 65 10 10 seconds 50 sheets ────────────────────────────── ──

As shown in Table 1, a lithographic printing plate using a support treated with an aqueous solution of a metal salt of a transition group element of Group VIII of the aliphatic monocarboxylic acid of the present invention was prepared using an untreated support ( Compared with Comparative Example 1), a remarkable effect was shown on the erasability after the development processing. In addition, compared with a lithographic printing plate of the present invention which is treated at a high temperature (100 ° C. or 95 ° C.) using pure water, barium acetate or an aqueous solution of calcium acetate, the lithographic printing plate of the present invention has the advantage that the non-image area is less likely to be stained during printing. Indicated.

[0044]

According to the present invention, a lithographic printing plate using a support treated with an aqueous solution of a transition metal salt of a group VIII of an aliphatic monocarboxylic acid at 30 to 60 ° C. at a temperature of 30 to 60 ° C. has a non-image area after development. The surface area per unit geometric area is 5 to 50 m ² / m ² , and the contact angle of water-in-oil droplets is 50 ° or less. By using such a photosensitive lithographic printing plate, the erasability after the development processing is improved, and the easiness of staining of the non-image area during printing is also improved.

Claims (2)

[Claims] 1. A photosensitive composition comprising a photosensitive layer provided on an aluminum support which has been anodized and then treated with an aqueous solution containing a transition metal salt of a group VIII of an aliphatic monocarboxylic acid at 30 to 60 ° C. Lithographic printing plate. In 2. A non-image portion after development, the surface area per unit geometric area is 5 to 50 m ² / m ^2, and the contact angle of water-in-oil is characterized in that 50 ° or less,
The photosensitive lithographic printing plate according to claim 1.