JPH0421855B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to photosensitive lithographic printing plates. Conventionally, most photosensitive lithographic printing plates (hereinafter referred to as PS plates) having a diazo photosensitive layer are made of organic salts and/or inorganic salts of diazo resin, high molecular weight polymers that can be mixed with this, and, if necessary, It is formed by coating a photosensitive liquid containing dyes, pigments, etc. on a thin aluminum plate. The printability of these PS plates often depends on the characteristics of the high molecular weight polymer. For example, in the case of a PS plate that undergoes alkaline development, the amount of hydrophilic functional groups in the structure of the polymer (for example, the number of hydroxy (-OH), carboxyl (-COOH) groups, etc. in the structure) It affects the characteristics or the ink receptivity of the printed area. When the amount of hydrophilic functional groups in the high molecular weight polymer is small, the ink receptivity in the printed areas improves, but the penetration rate (hereinafter referred to as
(referred to as development speed) tends to be slow. vice versa,
When the amount of hydrophilic functional groups is large, the development speed becomes faster, but the ink receptivity in the image area becomes worse. moreover,
Since the image area tends to swell, the image area is more likely to be damaged if a physical impact is applied during development. In order to improve the developability of such PS plates,
The PS plate must have the following properties (referred to as development acceleration). ○B It can be developed in a short time, and non-image areas do not become smudged during printing. ○B Even during long-term development, the image area swells relatively little and does not affect the image area. ○C Provide the same image area regardless of the length of development time. ○D Even if the developer concentration changes, the same image area is provided. However, as mentioned above, there is a limit to how the problem can be solved simply by changing the properties of the polymer compound mixed into the photosensitive layer. The present invention solves the above problems and provides a PS plate having the above-mentioned development accelerating properties without changing the properties of the PS plate and the polymer. / Or in a photosensitive layer mainly composed of an inorganic salt and an organic solvent-soluble polymer compound, the general formula [R is hydrogen or an alkyl group having 1 to 2 carbon atoms,
Alternatively, the aryl group, X ⁺ ₁ , X ⁺ ₂ represents hydrogen, an alkali metal, an alkaline earth metal (eg, sodium, potassium, calcium), or amines. ] The compound represented by is added in an amount of 0.1 to 0.1 to
The photosensitive lithographic printing plate is characterized in that it is added in an amount of 20% by weight. Examples of the compound represented by the general formula (1) include 4-hydroxy-2-sulfobenzoitschacide, 4-hydroxy-3-sulfobenzoitschacide, 5-hydroxy-3-sulfobenzoitschacide, 6-hydroxy-3-sulfobenzoitschacide,
Hydroxy-3-sulfobenzoitukaside, 2
-Hydroxy-4-sulfobenzoitsuquaside,
3-Hydroxy-4-sulfobenzoic acid, 5-sulfo-o-crosotic acid, 5-
Sulfo-p-cresotic acid, 5-sulfo-
m-Closotic acid, 1-hydroxy-5-
Examples include sulfonaphtoic acid and/or its alkali metal salts (eg, sodium, potassium salts), alkaline earth metal salts (eg, calcium salts), ammonium salts, and the like.
In particular, the o-,
The m-, p-isomers are preferred. At least one of these compounds is contained in an amount of 0.1 to 20% by weight, preferably 1 to 10% by weight, based on the total weight of the photosensitive layer.
Use % by weight. If it is less than 0.1% by weight, there is no development accelerating effect, and if it is more than 20% by weight, the photosensitive layer tends to discolor, and the image area after plate making swells.
It is easily scratched and the ink receptivity is also poor. The organic salt and/or inorganic salt of the diazo resin used in the present invention is preferably insoluble or sparingly soluble in water and soluble in an organic solvent. As a diazo resin with such properties,
Special Publication No. 40-8611, U.S. Patent No. 2922715, U.S. Patent
There are condensates of diazodiarylamines and active carbonyl compounds such as formaldehyde and acetaldehyde, which are described in 2946683 and the like. Examples of the diazoarylamine include 4-diazodiphenylamine, 4-diazo-3-methyldiphenylamine, 4-diazo-3'-methyldiphenylamine, 4-diazo-4'-methoxydiphenylamine, Examples include 4-diazo-3-methoxydiphenylamine. As a compound that forms an organic salt by combining with the above diazo resin, Japanese Patent Publication No. 40-2203, Japanese Patent Publication No. 41-6813,
There are compounds described in Japanese Patent Publication No. 47-1167, etc. For example, benzenesulfonic acid, p-toluenesulfonic acid, 2,5-xylenesulfonic acid, linear 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 (eg, sodium, potassium), alkaline earth metal salts (calcium), ammonium salts, and the like. As a compound that forms an inorganic salt by combining with the above diazo resin, Japanese Patent Publication No. 40-2203, Japanese Patent Application Publication No. 54-98613,
There are compounds described in US Pat. No. 4,093,465 and the like. For example, hydroborofluoric acid, hexafluorophosphoric acid,
Phosphotungstic acid, thiocyanic acid, and/or its alkali metal salts (e.g., sodium,
(potassium), alkaline earth metal salts (eg, calcium), ammonium salts, and the like. The above-mentioned diazo compounds can be used alone or in combination, and the content thereof is preferably in the range of about 5 to 30% by weight based on the total weight of the photosensitive layer. As the organic solvent-soluble polymer compound used in the present invention, Japanese Patent Publication No. 35-16157, Japanese Patent Publication No. 47-1167,
Tokuko Sho 49-36961, Tokuko Sho 50-34967, Tokko Shou 51-
6566, JP 50-30604, JP 50-36207, JP 50-118802, JP 57-2035, US Patent
No. 3,652,272 and US Pat. No. 3,660,097. Examples include epoxy resins, novolak resins, urethane resins, polyamide resins, styrene-maleic anhydride copolymer resins, copolymer resins of styrene and vinyltoluene with unsaturated dibasic acids, and acrylic resins. Particularly preferred are the copolymers described in US Pat. No. 4,282,301. The content of the above-mentioned organic solvent-soluble polymer compound is preferably in the range of about 70 to 95% by weight based on the total weight of the photosensitive layer of the present invention. In the present invention, dyes or pigments may be added to the photosensitive layer, if necessary. Examples of dyes include crystal violet, malachite green, Victoria blue, methylene blue, ethyl violet, rhodamine B, and basic oil dyes that are derivatives thereof.
BOH (manufactured by Hodogaya Chemical Industry Co., Ltd.), oil blue #603
(manufactured by Orient Chemical Industry Co., Ltd.), Permanent Blue #47 (manufactured by Daido Chemical Industry Co., Ltd.), and the like. Pigments include phthalocyanine blue, phthalocyanine green, dioxazine violet,
There are quinacridone red, indanthrene blue, etc., and neopomelo blue is a commercially available product.
FLE (manufactured by Bardate Aniline und Rieda Fabrication), oil blue BOS
(manufactured by Orient Chemical Industry Co., Ltd.), Spiron Blue
Examples include GNH (manufactured by Hodogaya Chemical Industry Co., Ltd.). The content of the above dye is about 0.5 to 20% by weight, and about 10% by weight based on the total weight of the photosensitive composition of the present invention.
A range of 15% by weight is preferred. Further, the content of the pigment is in the range of about 10 to 40% by weight, preferably in the range of about 20 to 30% by weight, based on the total weight of the photosensitive composition of the present invention. The developer used in the photosensitive lithographic printing plate of the present invention is a weakly alkaline aqueous solution. Examples of weakly alkaline aqueous solutions include metal salts of weak acids; for example, silicic acid, metasilicic acid, orthosilicic acid, phosphoric acid, pyrophosphoric acid,
Metaphosphoric acid, hexametaphosphoric acid, carbonic acid, tartaric acid,
Metal salts such as sodium salts, lithium salts, and potassium salts such as boric acid, or ammonia and its derivatives, such as alkylamines (e.g., amine compounds such as monomethyl, dimethyl, trimethyl, monoethyl, diethyl, and triethyl), or alkanols. Examples include aqueous solutions of alkaline compounds such as amines (eg, monoethanolamine, diethanolamine, diisopropanolamine). In order to improve the dissolution rate of unexposed areas in the photosensitive layer of these developers, activators and/or
Or a solvent can be added. As the activator, a hidden ionic surfactant, for example, a carbon number of 8 to
22 sulfate ester salts of alcohols (e.g. sodium lauryl sulfate, ammonium lauryl sulfate, sodium octyl sulfate, ammonium octyl sulfate, potassium octyl sulfate), sulfate ester salts of polyhydric alcohols (e.g. polyoxyethylene alkyl Sulfate soda salt: Kao Atlas Co., Ltd. Emar 20C), alkylaryl sulfonates (e.g. sodium dodecylbenzenesulfonate,
polyoxyethylene dodecyl phenyl sulfate soda salt, sodium alkylnaphthalene sulfonate, formalin condensate of sodium naphthalene sulfonate), sodium dialkyl sulfosuccinate,
Examples include fatty acid amide sulfonates, alkyl phosphates, and alkyl ether phosphates. As the solvent, alcoholic acids and ethers are preferred, but solvents that do not dissolve at least 10% in water (20°C) are most preferred. Examples of this type of solvent include alcohols such as benzyl alcohol,
Examples include DL-α-phenylethyl alcohol, 2-phenylethyl alcohol, phenyl cellosolve, propylene glycol monobutyl ether, and the like. The composition of the developer is 0.1 to 0.1% of the above alkaline compound.
3% by weight, surfactant 0.5~2% by weight, solvent 0~
2% by weight, preferably 0.1-1% by weight. When the photosensitive layer for a printing plate of the present invention is formed on a support, organic solvent-soluble polymer compounds, diazo compounds, oil dyes, etc. are mixed with an organic solvent such as a mixed solvent of methanol, methylene chloride, and ethyl acetate, N, After dissolving it in N-dimethylformamide, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. and coating it on a support using a coating machine (e.g., Whiler),
By drying, a photosensitive layer is formed on the support. Supports include brushed or ball polished aluminum plates, chemically polished aluminum plates,
An aluminum plate that has been brush polished and then anodized, an aluminum plate that has been electrolytically polished and then anodized, or a general support can be used. Such a support is subjected to chemical conversion treatment with alkali silicate, zirconium fluoride, alkyl titanate, trihydroxybenzoic acid, etc., boehmite treatment,
Alternatively, coating treatment with an aqueous solution of strontium acetate, zinc acetate, magnesium acetate, calcium benzoate, etc., coating treatment with polyvinylpyrrolidone, polyaminesulfonic acid, poly-2-ethylhydroxyacrylate, etc. can be performed as a post-treatment of the above treatment. . The invention is illustrated by the following examples. Example 1 Under a nitrogen stream, 0.3 g of azobisisobutyronitrile was added to 150 g of dioxane, and a mixture having the following composition was added dropwise thereinto while heating and stirring at 80 to 85°C. 2-Hydroxy-3-phenoxypropyl acrylate 50g Methyl methacrylate 25g Acrylonitrile 10g Methacrylic acid 2g After the dropwise addition, stirring was continued for 3 hours, and dioxane
After adding 150 g, the copolymer was poured into water to precipitate the copolymer. The precipitate was redissolved in 2-methoxyethanol, purified by dropping it into water, and dried under vacuum (70°C) to obtain copolymer (1). A 20% by weight 2-methoxyethanol solution of this copolymer was prepared, and the viscosity was measured to be 350 cps (25°C). On the other hand, the aluminum plate was cleaned with an aqueous solution of 3% caustic soda and 5% sodium silicate at 80°C, polished with a brush, and then polished with a sulfuric acid electrolyte.
Anodized for 1 minute (current density 2 ^A /dm ² , voltage
10V). After washing with water, the plate was coated with a 5% sodium metasilicate aqueous solution for 10 seconds to produce an anodized aluminum plate 1. After applying the following photosensitive liquid to the above aluminum plate 1 using a rotary coating machine (whiler), 80°C
was dried for 3 minutes to obtain a PS plate (). Diazo compound - dodecylbenzenesulfonate of condensate of 4-diazophenylamine and formaldehyde 0.3g Copolymer (1) 3.0g Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.)
0.1 g 5-sulfo-o-cresotic acid 0.08 g Ethylene glycol monomethyl ether 90 g N,N-dimethylformamide 10 g The coating amount after coating and drying was 1.7 g/m ² . A negative film was vacuum-adhered onto the photosensitive layer of this PS plate (), and after irradiating it with ultraviolet light for 30 seconds using a 30A single-phase carbon arc lamp at a distance of 60cm,
Using a developer having the composition shown below, the film was developed by immersion at room temperature for 5 seconds. Potassium silicate 20% aqueous solution 50g Phenyl glycol (H) (Nippon Nyukazai Co., Ltd.) 40g Potassium isopropylnaphthalenedisulfonate
5g Potassium sulfite 2g Water 903g Next, it was washed with water and examined to see if the unexposed areas were removed, and it was found that the unexposed areas were well removed. Furthermore, when proof printing was carried out using this printing plate, there was no scumming caused by ink in the non-image areas.
Therefore, it was found that development can be performed even in a short development time. On the other hand, the PS plate (), which was made in exactly the same manner as the above composition except that it did not contain 5-through-o-cresotic acid, had a film remaining in the non-image area even after development under the above development conditions. remained, making it impossible to develop. In addition, when we investigated the printing durability of the above-mentioned printing plate made of PS plate (), we found that compared to a normal printing plate (for example, a printing plate obtained by developing the PS plate () in the usual long time), The same number of printing plates can be obtained, and at the same time, the ink receptivity of the printed area is also improved.
It was good and warm. Next, the PS plates () and () were exposed to negative film in close contact with each other in the same manner as described above, and the developability was compared. Table 1 shows the results. Comparative Example 1 In place of "diazo compound - dodecylbenzenesulfonate of a condensate of 4-diazocyphenylamine and formaldehyde" used in Example 1, "diazo compound - a condensate of 4-diazocyphenylamine and formaldehyde" was used. A PS plate similar to the PS plate of Example 1 () was prepared, except that P-toluenesulfonic acid was used instead of “5-sulfosalicylate” and “5-sulfo-o-cresotic acid”.
Similar to Example 1, the developability was compared using the test method shown in Table 1. In the test method, the printed area easily swells and is easily damaged. In the test method, some of the streaks eluted over a long period of time. In the test method, it appeared that development was possible, but background smearing occurred due to inking. The test method is dirty. The test method is dirty. Example 2 Aluminum plate with a thickness of 0.25 mm and a width of 1000 mm (material
1100) was degreased with alkaline, washed with water, and then polished with a brush using a polishing agent containing a 20% aqueous solution of carborundum. Next, the polishing residue was thoroughly removed in a 10% caustic soda bath, washed with water, and then washed in an electrolytic solution (20%) containing 2.5% hydrochloric acid and 0.1% sodium chloride at a current density of 10 ^A /dm ² for 10 seconds. AC electrolytic polishing was performed. Then washed with water and placed in a 10% sulfuric acid bath (30°C) at current density.
After anodizing for 60 seconds at 2 ^A / ^dm2 and washing with water,
% potassium silicate bath (40°C) at a current density of 2 ^A /
AC anodic oxidation treatment was performed for 15 seconds at dm ² , washed with water, and dried to obtain an anodized aluminum plate 2. A photosensitive liquid with the following composition is applied to this aluminum plate 2 using a spin coater, dried, and then the PS plate ()
I got it. The same diazo compound used in Example 1
0.3g Styrene-maleic anhydride copolymer resin 3g Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.)
0.1 g 5-sulfo-m-cresotic acid 0.08 g Ethylene glycol monomethyl ether 90 g N,N-dimethylformamide 10 g The coating amount after drying was 2.0 g/m ² . When the above PS plate () was subjected to a comparative test similar to that in Example 1, it was found that PS, which has the ability to accelerate development,
It has been confirmed that this is the version. Example 3 Anodized aluminum plate 2 used in Example 2
The following photosensitive compositions-1 and 2 were used.
was applied onto the plate 2 in a coating amount of 1.7 g/m ² using a rotary coater, and dried to obtain PS plates () and (). Photosensitive composition-1: Diazo compound used in Example 1 0.3g Copolymer (1) of Example 1 3g Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.)
0.1g 6-hydroxy-3-sulfobenzoitukaside
0.08g Ethylene glycol monomethyl ether 90g N,N-dimethylformamide 10g Photosensitive composition-2; Diazo compound used in Example 1 0.3g Copolymer (1) of Example 1 3g Oil Blue #603 (Orient Chemical Industry Co., Ltd.) (manufactured by Co., Ltd.)
0.1g Potassium salt of 5-sulfo-o-cresotic acid 0.08g Ethylene glycol monomethyl ether 90g N,N-dimethylformamide 10g Comparative tests similar to those in Example 1 were conducted on each of the PS plates () and (). Result, 6
-PS board coated with photosensitive composition-1 added with hydroxy-3-sulfozone zoitschacide ()
applied photosensitive composition-2 to which potassium salt of 5-sulfo-o-cresotic acid was added.
It showed almost the same printing suitability as PS board (). From the above Examples 1, 2, and 3, it is clear that the photosensitive lithographic printing plate of the present invention exhibits better printing suitability than the conventional one. Furthermore, the photosensitive lithographic printing plate of the present invention is also excellent in terms of stability over time.

[Table] Example 4 A photosensitive solution having the following composition was applied to the anodized aluminum plate prepared in Example 1, and the coating amount after drying was
It was applied at a weight of 1.7 g/m ² . Copolymer (1) in photosensitive liquid composition Example 1 3.0 g Diazo compound - 2-hydroxy-4- condensate of 4-diazodiphenylamine and formaldehyde
Methoxybenzophenone-5-sulfonate
0.3g 6-hydroxy-3-sulfobenzoitukaside
0.08g Victoria Blue BOX (manufactured by Hodogaya Chemical Industry Co., Ltd.)
0.1g Ethylene glycol monomethyl ether 90g N,N'-dimethylformamide 10g The PS plate prepared in this manner is referred to as (). In addition, 6-hydroxy-3 in the above photosensitive liquid composition
-In place of sulfobenzoitschacide, P-toluenesulfonic acid (formula (2) below) and orthosulfobenzoitschacide monoammonium salt (formula below)
Using the same amount of (3)), do the PS version () and () in the same way.
was created.

【formula】

[Formula] Next, PS of each of these (), (), ()
The plate was exposed as in Example 1 and developed for 5 seconds with the same developer. As a result, PS plate () could be developed quickly, but () and () remained with residual film, which caused stains. Further, this developing solution was diluted 3 times and developed for 30 seconds, and the non-image areas were observed for removal. PS version ()
It came off cleanly and no stains appeared on the proof. However, () could not be removed completely and stains appeared. From this, the PS version () of the present invention is
It can be seen that the developability is excellent. Furthermore, after storing these PS plates for two weeks in a constant temperature and humidity chamber at 45°C and 75% temperature, they were exposed in the same manner as in Example 1, developed for 30 seconds, and made proofs. (), () Dirt occurs in the non-printed areas,
I couldn't print. As is clear from the results of the above examples, the compound represented by the general formula (1) of the present invention, that is, the compound having a hydroxyl group, a carboxylic acid group, and a sulfonic acid group in the same benzene nucleus, It is more effective than a diazo resin salt and/or inorganic salt and an organic solvent-soluble polymer compound.

Claims (1)

[Scope of Claims] 1. A photosensitive layer containing an organic salt and/or inorganic salt of a diazo resin and an organic solvent-soluble polymer compound as a main component has the general formula [R is hydrogen or an alkyl group having 1 to 2 carbon atoms,
Alternatively, the aryl group, X ⁺ ₁ , X ⁺ ₂ represents hydrogen, an alkali metal, an alkaline earth metal (eg, sodium, potassium, calcium), or amines. ] The compound represented by is added to the total weight of the photosensitive layer.
A photosensitive lithographic printing plate characterized in that it is added in an amount of 0.1 to 20% by weight.