JPH0290163A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain a photosensitive planographic plate superior in storage stability by incorporating a specified compound in a photosensitive composition composed essentially of a negative type diazo resin and an organic solvent- soluble high polymer. CONSTITUTION:The photosensitive composition composed essentially of the negative type diazo resin and the organic solvent-soluble high polymer contains the aromatic compound or its salt having one sulfonic acid group and at least 2 carboxy groups in an amount of 0.1-20wt.% of the total weight of the photosensitive layer, and if <0.1wt.%, the effect of improving storage stability is lost, and if >20wt.%, the photosensitive layer becomes liable to discolor, and image lines after forming a printing plate, swell, and become easily scratchable, inking and printing resistance deteriorate, thus permitting the photosensitive planographic plate superior in storage stability to be obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to photosensitive compositions.

(Prior art) Conventionally, a photosensitive lithographic printing plate (
Many of the diazo resins (hereinafter referred to as PS plates) are made of diazo (sealing resins, which can be mixed with organic salts and/or inorganic salts of condensation products of mainly paradiazodiphenylamines and aldehydes; high-molecular polymers) And, necessary! = dye, depending on
It is formed by applying a photosensitive liquid containing pigments etc. onto a thin aluminum plate. When it is exposed to actinic light through a transparent negative, the diazo resin in the exposed areas decomposes and becomes insoluble. On the other hand, the surface of the support is exposed by dissolving and removing the unexposed areas with water. If a support having a surface that has been previously subjected to a hydrophilic treatment is used, the parent wood layer will be exposed in the unfrosted areas by development. Therefore, on an offset printing press, this part accepts water and repels ink.5 Also, the decomposed part of the diazo nail exhibits lipophilic properties and repels water and accepts ink. That is, 2: printing t, t t-1 gives a so-called negative-positive type O printing plate.

When the counter anion of the diazonium salt is a water-soluble diazo resin such as a mineral acid such as hydrochloric acid, sulfuric acid, or a double salt with zinc chloride, moisture: two pairs. It was unstable and had problems with poor storage stability. In order to improve this: this diazo (anion that forms a stable salt with the seal, and makes the seal soluble in two solvents, for example, Japanese Patent Publication No. 47-1167 or A is a U.S. Patent No. 3
Specification No. 300309: =described-); organic salts such as organic sulfonates, or: JP-A-54-9
Inorganic salts such as halogenated Lewis acid salts as described in Publication No. 8613 are known. Printing materials are known in which a mixture of:

Additionally, phosphoric acid is commonly used as a stabilizer for diazo resins.
Phosphorous acid, birophosphoric acid, oxalic acid, tartaric acid, citric acid,
Malic acid, pyridinedicarboxylic acid, boric acid, benzenesulfonic acid, toluenesulfonic acid, naphthalenesulfonic acid, alkylnaphthalenesulfonic acid, 4-methoxy-2-
Hydroxybenzophenone-5-sulfonic acid, polyacrylic acid and its copolymers, polyvinylphosphonic acid and its copolymers, polyvinylsulfonic acid and its copolymers,
5-nitronaphthalene-1-phosphonic acid, 4chlorophenoxymethylphosphonic acid, sodium phenyl-methyl-pyrazolone sulfonate, 2-phosphonobutanetricarboxylic acid-1,2,4,1-phosphonoethanetricarboxylic acid-1,2 It is known that storage stability can be improved by adding , 2,1-hydroxyethane-1,1-disulfonic acid, etc. However, traditional print editions
Storage stability, especially storage stability under high temperature and high humidity conditions, is still not necessarily sufficient, and improvements have been desired.

[Problem to be solved by the invention]

Therefore, an object of the present invention is to provide a photosensitive composition for obtaining a photosensitive lithographic printing plate having excellent storage stability.

[Means to solve the problem]

The present invention provides a photosensitive composition mainly composed of a negative type diazo 1 sealant and an organic solvent-soluble polymer compound, j = an aromatic compound having one sulfonic acid group and at least two carboxylic acid groups, or The salt is 0.1 per liter of the total weight of the photosensitive layer.
This is a photosensitive composition characterized in that it is added in an amount of 20% by weight.

The present invention will be specifically explained below.

The stabilizer for the diazo resin used in the present invention is an aromatic compound having one sulfonic acid group and at least two carboxylic acid groups or a salt thereof, and has the following general formula (I).
Or it can be shown as (II).

General formula (1) General formula (II) General formula (
1) Specific examples of the compound represented by (II) include those shown below.

OJ Sυ, H 5Q,)I SQ,)I mouth! death! Examples of the salts of the above compounds include alkali metal salts (e.g., sodium and potassium salts), alkaline earth metal salts (e.g., calcium salts), and ammonium salts. Among these, special: 24-sulfophthalic acid is preferred.

At least one of these compounds is contained in an amount of 0.1 to 20% by weight, preferably 0.5 to 1% by weight based on the total solid content of the photosensitive composition.
O weight percent is used. If it is less than 0.1% by weight, there will be no effect on storage stability, and if it is more than 20% by weight, the photosensitive layer will easily discolor, the image area after plate making will swell, be easily scratched, and the ink will build up. The quality and printing durability also deteriorate.

The diazo resin used in the present invention is preferably insoluble or poorly soluble in water and soluble in organic solvents. Diazo resins having such properties include condensates of diazodiarylamines and active carbonyl compounds such as formaldehyde and acetaldehyde, which are described in Japanese Patent Publication No. 40-8611, U.S. Patent No. 2922715, U.S. Patent No. 2946683, etc. There is. Examples of the above diazodiarylamines include 4-diazodiarylamine, 4-diazo-3-methyldiphenylamine,
4-Diazo-3'-methyldiphenylamine, 4-diazo-4'-methquinediphenylamine, 4-diazo-3
-methoxydiphenylamine and the like.

The negative-type diazo 1 sealant of the present invention can be used as the above-mentioned diazo (nail fixing salt).

The above-mentioned diazo (as a compound that combines with sealing to form an organic salt)
No., Japanese Patent Publication No. 47-1167, etc.: There are compounds described in 2. For example, benzenesulfonic acid, p-toluenesulfonic acid, 2,5-xylenesulfonic acid, direct type, side chain type dodecylbenzenesulfonic acid (commonly known as dodecylbenzenesulfonic acid), 2-hydroxy-4-methoxy-benzophenone-5 - Sulfonic acid, methanyl yellow, 2-chlorotoluene-4-sulfonic acid, and/or its alkali metal salts (e.g., sodium, potassium), alkaline earth metal salts (e.g., calcium), ammonium salts, etc. .

The above-mentioned diazo (as a compound that forms an inorganic salt by combining with encapsulation)
There are compounds described in No. 3 and US Pat. No. 4,093,465. For example, borohydrogen, hexafluorophosphoric acid, phosphotungstic acid, thiocyanic acid, and/or
or its alkali metal salts (e.g. sodium, potassium), alkaline earth metal salts (e.g. calcium),
Examples include ammonium salts.

The above diazo compounds can be used alone or in combination.

Examples of organic solvent-soluble polymer compounds used in the present invention include Japanese Patent Publication No. 35-16157 and Japanese Patent Publication No. 47-1167.
No., Special Publication No. 49-36961, Special Publication No. 50-3496
No. 7, Special Publication No. 5I-6566, Japanese Patent Publication No. 50-3060
No. 4, JP-A-50-36207, JP-A-50-118
No. 802, JP-A No. 57-2035, U.S. Patent No. 365
No. 2272, US Patent No. 3,660,097, etc.! = Polymers described above include polyamides, polyethers, polyesters, polycarbonates, polystyrene,
Examples include polyurethane, polyvinyl chloride and its copolymers, polyvinyl butyral (sealed), polyvinyl formal (sealed), shellac, epoxy (sealed), phenolic resin, and acrylic (sealed).

Particularly suitable: Copolymers containing acrylic acid, methacrylic acid, crotonic acid, or maleic acid as essential components as organic polymer compounds, such as JP-A-50-1188
2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacrylonitrile, acrylic acid or methacrylic acid and optionally other copolymerizable monomers as described in Japanese Patent No. 02 Multi-component copolymer with
Acrylic acid or methacrylic acid whose terminal end is a hydroxy group and is esterified with a group containing a dicarboxylic acid ester residue, as described in Publication No. 120903,
Acrylic acid or methacrylic acid and necessary! = Other copolymerizable de; monomer and O multi-component copolymer, JP-A-54-98614 j = 1ffi1. having an aromatic hydroxyl group as described. t (9'1LC-1'
N-(4-hydroxyphenyl)methacrylamide, etc.), acrylic acid or methacrylic acid, and if necessary, other copolymerizable monomers, as described in JP-A-56-4144; One example is a multi-component copolymer consisting of alkyl acrylate, acrylonitrile or mecrylonitrile and an unsaturated carboxylic acid. In addition, acidic polyvinyl alcohol derivatives and acidic cellulose derivatives are also useful. Also, JP-B No. 5419773 and JP-A No. 57-9474 which solubilized polyvinyl acetal and polyurethane with alkali.
No. 7, No. 60-182437, JP-A-62-5824
The polymer compounds described in No. 2 and JP-A-62-123453 are also useful.

The content of these diazo (nail fingers and polymer compounds) added to the photosensitive composition is based on the total amount of both of them.
Suitably, it is expressed in % by weight. Contains diazo 1 sealant
If the sensitivity is lower than 3%, the photocuring of the polymer compound will be insufficient and a binary cured film will appear during development. Therefore, the membrane swells and becomes weak. reverse! If the content of Nidiaso 1 sealant exceeds 30%, the sensitivity will be low and this will be a practical problem. Therefore, a more preferable range: Diazo (sealing 5 to 2
When it is 0% by weight, the polymer compound is 95-80% by weight.

The light regulating composition used in the present invention'7: 2. Further: 2. Various additives can be added. For example, alkyl ethers (e.g. ethylcellulose, methylcellulose), fluorine-based surfactants or silicone-based surfactants to improve coating properties, plasticizers (e.g. trichome) to impart flexibility and abrasion resistance to the coating. acridine dye, cyanine dye, styryl dye as a coloring substance to visualize the image of developer solution , triarylmethane dyes and phthalonanine-; Which Hiko page! Stabilizers (phosphoric acid, phosphorous acid, birophosphoric acid, oxalic acid, tartaric acid, citric acid, malic acid, pyridine dicarboxylic acid, boric acid, -benzene sulfonic acid) , toluenesulfonic acid, naphthalenesulfonic acid, alkylnaphthalenesulfonic acid, 4-methoxy-2-hydroxybenzophene-5-sulfonic acid, polyacrylic acid and its copolymers, polyvinylphosphonic acid and its copolymers, polyvinylsulfone Acids and copolymers thereof, 5-nitronaphthalene-1-phosphonic acid, 4-chlorophenoxymethylphosphonic acid, sodium phenyl-methyl-pyrazolone sulfonate, 2-phosphonobutanetricarboxylic acid-1,2,4,1-phosphono Ethanetricarboxylic acid-1,2,2,1-hydroxyethane-1
(1-disulfonic acid, etc.) can be added.

The amount of these additives added varies depending on the purpose for which they are used, but is generally 0.5 to 30% by weight based on the total solid content of the photosensitive composition.

The photosensitive composition of the present invention is dissolved in a suitable organic solvent and applied onto a support having a hydrophilic surface to a dry coating weight of 0.3 to 5.
g/m'', a photosensitive lithographic printing plate can be obtained.The concentration of the photosensitive composition at the time of coating is 1.
The coating solvent used is preferably methanol, ethanol, butanope ethylene chloride, chlorobenzene, tetrahydrofuran, acetone, methyl ethyl ketone, cyclohexanone,
Ethyl acetate, butyl acetate, methyl lactate, ethyl lactate At,
Ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, 1-methoxy-2-7” lovanol, dimethylformamide, dimethyl sulfoxide, γ-butyrolactone,
Diacetone alcohol, a mixed solvent thereof, or a mixed solvent obtained by adding a small amount of a solvent that does not dissolve the diazo resin or the polymer compound, such as water or toluene, to these solvents or mixed solvents are also suitable.

Application of the photosensitive composition of the invention: Suitable support 1:.

is a dimensionally stable plate. Such dimensionally bistable plate-like materials include those conventionally used as supports for printing plates, and these can be suitably used in the present invention. Such supports include paper, paper laminated with plastics (e.g. polyethylene, polypropylene, polystyrene, etc.), plates of metals such as aluminum (including aluminum alloys), zinc, copper, etc., cellulose diacetate, Films of plastics such as cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acecool, etc., laminated or vapor-deposited with metals such as those mentioned above. Includes paper or plastic film. Among these supports, aluminum plates are particularly preferred because they are extremely dimensionally stable and inexpensive.

Among the aluminum plates, roughened aluminum is more preferred and can be produced in various ways. For example, wire brush graining, plan graining in which a slurry of grains to be polished is poured and the surface is roughened with a nylon 77" brush, ball graining, chemical graining, electrolytic graining, and combinations of these roughening methods. Composite graining: The surface is grained.

Next required: two parts sulfuric acid, phosphoric acid, oxalic acid, boric acid,
It is preferable to form a strong passive film on the aluminum surface by performing anodization in chromic acid, sulfamic acid, or a mixed acid thereof using a direct current or alternating current power source. Such a passive film itself makes the aluminum surface hydrophilic, but further details are required as described in US Pat. No. 2,714,066 and US Pat. No. 3,181,461. The silicate treatments (sodium silicate, potassium silicate) described in U.S. Pat. No. 2,946,638, the potassium fluorozirconate treatments described in U.S. Pat. 247;
Specification No. 3; Polyacrylic acid treatment described in German Patent No. 1,134,093 and British Patent No. 1;
230.447 The above details! Polyvinylphosphonic acid treatment described in Japanese Patent Publication No. 44-6409; Phosphonic acid treatment described in US Pat. No. 3,307
t) phytic acid treatment as described in No. 951,
JP-A-58-16893 and JP-A-58'-18291
Each of the publications in this issue: Solutions containing a hydrophilic organic polymer compound and a divalent metal described in 5) Particularly preferred. Other hydrophilic treatment methods include silicate electrodeposition described in US Pat. No. 3,658,662.

In the present invention j, the amount of the photosensitive composition applied on the roughened aluminum plate is 0.3 as solid content.
~5 g/m' is preferred, more preferably 0.5
/ 3.5 g/m'. In this way, t; the solid content concentration of the photosensitive composition that gives the coating amount j'! 1 to 50% by weight is suitable, preferably 2 to 20% by weight.

On an aluminum plate: Conventionally known methods such as roll coating, bar coat ink, spray coating, curtain coating, and spin coating can be used to apply the biphotosensitive composition solution. It is preferable to dry the photosensitive composition solution at 50 to 120°C. Drying method: Well, you can start with a low temperature and then dry it at a high temperature after preliminary drying, or you can dry it directly at a high temperature.

A lithographic printing plate having a photosensitive composition layer coated and dried on a roughened aluminum plate can be developed with an aqueous developer after image exposure to obtain a negative relief image of the original image. . , fog light 1 Suitable light sources include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps, strobes, ultraviolet rays, laser beams, and the like.

The aqueous developer used in the above photosensitive planographic printing plate refers to one with a pH of 6 to 13 and a water content of 75% by weight or more, and requires: smaller amounts of organic solvents, surfactants, alkaline agents, and dirt. Inhibitors, water softeners, etc. can be added. For example, JP-A-51-77401, JP-A-51-80
No. 228, JP-A-53-44202, JP-A-55-5
Each publication j= No. 2054 and JP-A No. 57-136647
A developing solution as described above, containing an organic solvent (benzyl alcohol, ethylene glycol monophenyl ether) whose solubility in water is 10% by weight or less at room temperature, an alkali agent (triethanolamine, jetanolamine, monoethanolamine, sodium phosphate, sodium carbonate), anionic surfactants (aromatic sulfonates,
dialkyl sulfosuccinate, alkylnaphthalene sulfonate, fatty acid salt, alkyl sulfate salt), nonionic surfactant (polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene polyoxypropylene block polymer), and antifouling agents (sodium sulfite,
sulfopyrazolone sodium salt) and water softeners (ethylenediaminetetraacetic acid sodium salt, nitrilotriacetic acid trisodium salt)1. This invention consists of an aqueous solution that combines and dissolves the two inventions! According to the above, it is possible to provide a mosquito photosensitive composition for obtaining a photosensitive lithographic printing plate having excellent storage stability.

:Example Next: This example! The present invention will be explained from the second part.

Example 1 and Comparative Examples, to F. An aluminum plate was immersed in a sodium phosphate aqueous solution to degrease it, polished with a brush, electrolytically etched, then anodized in sulfuric acid, and further treated in a sodium disilicate aqueous solution.
It was immersed twice to make it hydrophilic.

This hydrophilic treated aluminium: 2 or less photosensitive liquid (1
) to obtain photosensitive planographic printing plates 1 and 8 to F. The coating amount was 1.5 g/m''.

Photosensitive liquid (1) However, organic polymer compound (1): Yo, in weight ratio, p -
Hydroxyphenyl methacrylamide/2-hydroxyethyl methacrylate/acrylonitrile/methyl methacrylate/methacrylic acid = 1O/20/25/35/
This is a copolymer of No. 10 with an average molecular weight of 60.000.

The obtained photosensitive lithographic printing plates 1 and A-F were passed through a step wedge (optical density increasing stepwise by 0.15) and printed at 50% by jet printer 2000 (manufactured by I Kikuoak Seisakusho). The plate was exposed to light for seconds, and then developed with developer-1 below to obtain a lithographic printing plate.

SARO J: The storage stability of photosensitive lithographic printing plates 1 and A to F was examined. However, the storage stability in the table is 45℃ and humidity 7.
Stored in a 5% atmosphere and in an oven at 60°C;
The composition of developer-1, which showed changes in sensitivity and staining performance after printing 10,000 sheets, as compared to the photosensitive lithographic printing plate immediately after production, is as shown in j2 below.

Phenomena liquid-1 Same as Comparative Examples A-E c) Has printing durability';

Examples 2 and 3 In Example 1, the following stabilizers were used, and the same t'lt! : A photolithographic printing plate was prepared.

When the storage stability of these samples was investigated, the same good results as in Example 1 were shown. In addition, other performances as a lithographic printing plate were also good.

Compared to Comparative Example Fj in which no stabilizer was added, Comparative Examples A to E in which conventional stabilizers were added had smaller sensitivity fluctuations over time and less deterioration in stain performance, but It turns out that this is sufficient.

(In practice, a problem will occur if the clear sensitivity fluctuation is 3 steps or more and the stain performance is 3 or more steps.) On the other hand, Example 1 has superior storage stability even when used in a small amount compared to the conventional stabilizer j2. I understand.

Example 1 had good image strength and ink receptivity.TsujiExamples 4 and 5In place of photosensitive liquid (1) in Example 1, the following photosensitive liquid (
A photosensitive lithographic printing plate was prepared in the same manner except that 2) or (3) was used, and similar to Example 1, good results with excellent storage stability were obtained.

Photosensitive liquid (2) Photosensitive? 711 (3) However, here, the organic polymer compound (2) has a weight ratio of 2-hydroxyethyl methacrylate/acrylonitrile/ethyl meccrylate/methacrylic acid = 43/12/401
5 copolymer with an average molecular weight of 11 (1.0 (10).

However, here, the organic polymer compound (3) has a molar ratio of 4.
Ethylene bromohydrin is added to the polyurethane obtained by polyaddition of 4'-diphenylmethane diisocyanate/1.6-hexamethylene diisocyanate/2゜2-bis(hydroxymethyl)propionic acid = 60/40/l 00. It is a polyurethane in which a part of the carboxyl group is hydroxyethylated by reacting the following.

Average molecular weight according to GPC measurement j= is 45° It was 000.

: Hi slander Kano +) carboxyl fundamental The amount is 1.2 It was Qmeqz'g.

Claims (1)

[Claims] An aromatic compound having one sulfonic acid group and at least two carboxylic acid groups or a salt thereof is added to a photosensitive composition containing a negative-working diazo resin and an organic solvent-soluble polymer compound as main components in the photosensitive layer. A photosensitive composition characterized in that the amount thereof is added in an amount of 0.1 to 20% by weight based on the total weight.