JPH0462574B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a photosensitive composition, and more specifically,
The present invention relates to a photosensitive composition for lithographic printing plates (hereinafter simply referred to as "photosensitive composition") that has a film with excellent abrasion resistance and can be developed with an aqueous developer. [Prior art] Conventionally, the abrasion resistance of a film has been improved. Many photosensitive compositions are known.For example, U.S. Pat.
Polyamide resin described in specification No. 3751257,
Polyvinyl acetal resins such as polyvinyl formal resins and polyvinyl butyral resins as described in British Patent No. 1,074,392, linear polyurethane resins as described in US Pat. No. 3,660,097, bisphenol A Photosensitive compositions containing epoxy resins condensed from and epichlorohydrin, celluloses such as cellulose alkyl ether, cellulose acetate, and cellulose acetate phthalate are known. Furthermore o
- Nylon shown in U.S. Pat. No. 2,826,501 as a binder to a quinonediazide compound, polyurethane, polyvinyl chloride, epoxy resin described in Japanese Patent Publication No. 42,448/1986;
Photosensitive compositions containing polyvinyl ether and the like described in No. 16049 are known. However, these materials have the disadvantage that sufficient development cannot be achieved with an aqueous developer mainly composed of water if the polymer is added to the extent that the abrasion resistance is improved.
Although the use of an aqueous developer is highly desirable, as it is odorless, non-flammable, non-toxic, and easy to dispose of waste liquid, no photosensitive composition that can be developed with an aqueous developer with excellent abrasion resistance has been found. Not yet. [Object of the Invention] Accordingly, an object of the present invention is to provide a photosensitive composition for lithographic printing plates that has excellent abrasion resistance and is developable with an aqueous developer. [Structure of the Invention] The object of the present invention is to provide a photosensitive composition for lithographic printing plates, which is characterized by containing an anionic polyurethane resin having an anionic group selected from -COO ^- group or -SO ₃ ^- group. achieved by. The photosensitive composition according to the present invention is suitable for being coated on a support and used to form a photosensitive lithographic printing plate. The present invention will be explained in detail below. (Anionic polyurethane resin) The anionic polyurethane resin according to the present invention has been extensively researched and is commercially available, but it can be found in Japanese Patent Publications No. 15874-1983 and Japanese Patent Publication No. 15874-1989.
No. 25435, Special Publication No. 1977-2199, Special Publication No. 1977-27904
It can be easily synthesized by the method described in US Pat. No. 3,412,054 and the like. That is, it can be obtained by bonding an anionic group selected from a ^-COO- group or ^a _-SO3- group to a polyurethane chain. Introduction of such an anionic hydrophilic group is possible by a method using an active hydrogen compound having a carboxylate or sulfonate as a chain extender, as disclosed in Japanese Patent Publication No. 49-2199; A method using an amino acid as a chain extender, as disclosed in Japanese Patent Publication No. 15517, and a method using a polyol containing a metal sulfonic acid salt as a chain extender, as disclosed in Japanese Patent Publication No. 47-22707. , special public service in 1977
This can be easily carried out by the method disclosed in No. 25435, in which the aromatic ring of an aromatic isocyanate-based urethane prepolymer is sulfonated, followed by chain extension. Typical commercially available anionic polyurethane resins are various HYDRAN (aqueous polyurethane resins) sold by Nippon Reichhold Co., Ltd. The amount of anionic polyurethane resin contained in the photosensitive composition according to the present invention is from 2 to 70% by weight, more preferably from 5 to 50% by weight. (Photosensitive Composition) The photosensitive composition to which the above-mentioned anionic polyurethane resin is added will be described below. (1) Composition made of diazo resin The diazo resin represented by the condensate of p-diazodiphenylamine and paraformaldehyde may be water-soluble or water-insoluble, but preferably water-insoluble and water-insoluble. Those soluble in common organic solvents are used. Particularly preferred diazo compounds include salts of condensates of p-diazophenylamine and formaldehyde or acetaldehyde;
For example, phenolic salts, fluorocaprates, and triisopropylnaphthalenesulfonic acid, 4,
4-biphenyldisulfonic acid, 5-nitroortho-toluenesulfonic acid, 5-sulfosalicylic acid,
2,5-dimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-chloro-5-nitrobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, 1-naphthol- It is a compound having two or more diazo groups in one molecule, such as salts of sulfonic acids such as 5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoylbenzenesulfonic acid, and para-toluenesulfonic acid. Other desirable diazo resins include 2,5-dimethoxy-4-
Condensates of p-tolylmercaptone benzenediazonium and formaldehyde, and condensates of 2,5-dimethoxy-4-morpholinobenzenediazonium and formaldehyde or acetaldehyde are included. Also preferred are the diazo resins described in British Patent No. 1312925. A binder is additionally added to the photosensitive composition consisting of diazo resin. Various polymeric compounds can be used as such binders, but those containing groups such as hydroxy, amino, carboxylic acid, amide, sulfonamide, active methylene, thioalcohol, and epoxy are preferred. Such preferred binders include sierachiac as described in GB 1350521, hydroxyethyl acrylate units or hydroxyl acrylate units as described in GB 1460978 and US 4123276. Included are polymers containing ethyl methacrylate units as a main repeating unit, phenolic resins described in British Patent No. 1074392, and the like. It is appropriate that the content of the binder is 40 to 95% by weight in total with the anionic polyurethane resin, based on the photosensitive composition of the present invention. As the amount of binder increases (ie, as the amount of diazo resin decreases), the photosensitivity naturally increases, but the stability over time decreases. The optimum amount of binder is about 70-90% by weight. Additives such as phosphoric acid, dyes and pigments described in US Pat. No. 3,236,646 can also be added to the diazo resin composition. (2) Composition comprising an o-quinonediazide compound A particularly preferred o-quinonediazide compound is an o-quinonediazide compound.
Naphthoquinonediazide compounds, such as U.S. Patent No. 2766118, U.S. Patent No. 2767092, U.S. Patent No. 2772972
No. 2859112, No. 2907665, No. 2907665, No. 2859112, No. 2907665, No.
No. 3046110, No. 3046111, No. 3046115, No. 3046118, No. 3046119, No. 3046120,
Same No. 3046121, Same No. 3046122, Same No. 3046123,
Same No. 3061430, Same No. 3102809, Same No. 3106465,
It is described in numerous publications including the specifications of the same No. 3635709 and the same No. 3647443, and these can be suitably used. Among these, o-naphthoquinonediazide sulfonic acid ester or o-naphthoquinonediazidecarboxylic acid ester of an aromatic hydroxy compound, and o-naphthoquinonediazide sulfonic acid amide or o-naphthoquinonediazidecarboxylic acid amide of an aromatic amino compound are particularly preferred. , in particular, a condensate of pyrogallol and acetone described in U.S. Pat. No. 3,635,709 and o-naphthoquinonediazide sulfonic acid subjected to an ester reaction, and U.S. Pat. No. 4,028,111.
British patent no.
Ester reaction of o-naphthoquinonediazide sulfonic acid or o-naphthoquinonediazidecarboxylic acid to a homopolymer of p-hydroxystyrene or a copolymer of this and other copolymerizable monomers as described in No. 1494043 What they have done is very good. Although these o-quinonediazide compounds can be used alone, it is preferable to use them in combination with an alkali-soluble resin. Suitable alkali-soluble resins include novolac-type phenolic resins, specifically phenol formaldehyde resins, o-cresol formaldehyde resins, m
-Includes cresol formaldehyde resin, etc. Further, as described in U.S. Pat. No. 4,123,279, along with the above-mentioned phenolic resin, t
It is even more preferable to use a condensate of formaldehyde and phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms, such as -butylphenol formaldehyde resin. The alkali-soluble resin is contained in an amount of about 50 to about 85% by weight, more preferably 60 to 80% by weight, based on the total amount with the o-quinonediazide compound. The photosensitive composition made of the o-quinonediazide compound can further contain pigments, dyes, plasticizers, etc., if necessary. (3) Composition Comprising a Photosensitive Azide Compound Suitable photosensitive azide compounds include aromatic azide compounds in which an azide group is bonded to an aromatic ring directly or via a carbonyl group or a sulfonyl group. In these, the azide group is decomposed by light to produce nitrene, which undergoes various reactions and becomes insolubilized. Preferred aromatic azide compounds include compounds containing one or more groups such as azidophenyl, azidostyryl, azidobenzal, azidobenzoyl and azidocinnamoyl, such as 4,4'-diazidochalcone,
4-azido-4'-(4-azidobenzoylethoxy)chalcone, N,N-bis-p-azidobenzal-p-phenylenediamine, 1,2,6-tri(4'-azidobenzoxy)hexane, 2-azide -3-chloro-benzoquinone, 2,4-diazide-4'-ethoxyazobenzene, 2,6-di(4'-
azidobenzal)-4-methylcyclohexanone 4,4'-diazidobenzophenone, 2,5-diazido-3,6-dichlorobenzoquinone, 2,5-
Bis(4-azidostyryl)-1,3,4-oxadiazole, 2-(4-azidocinnamoyl)
Thiophene, 2,5-di(4'-azidobenzal)
Cyclohexanone, 4,4'-diazidiphenylmethane, 1-(4-azidophenyl)-5-furyl-2-pent-2,4-dien-1-one, 1-
(4-azidophenyl)-5-(4-methoxyphenyl)-penta-1,4-dien-3-one, 1
-(4-azidophenyl)-3-(1-naphthyl)
Propen-1-one, 1-(4-azidophenyl)
-3-(4-dimethylaminophenyl)-propan-1-one, 1-(4-azidophenyl)-5-phenyl-1,4-pentadien-3-one, 1-
(4-azidophenyl)-3-(4-nitrophenyl)-2-propen-1-one, 1-(4-azidophenyl)-3-(2-furyl)-2-propene-
1-one, 1,2,6-tri(4'-azidobenzoxy)hexane, 2,6-bis-(4-azidobenzylidine-pt-butyl)cyclohexanone, 4,4'-diazidobenzalacetone , 4-
4'-Diazidostilbene-2,2'-disulfonic acid, 4'-azidobenzalacetophenone-2-sulfonic acid, 4,4'-diazidostilbene-α-carboxylic acid, di-(4-azido -2'-Hydroxybenzal)acetone-2-sulfonic acid, 4-azidobenzalacetophenone-2-sulfonic acid, 2-
Azido-1,4-dibenzenesulfonylaminonaphthalene, 4,4'-diazide-stilbene-2,
Examples include 2'-disulfonic acid anilide. In addition to these low molecular weight aromatic azide compounds, there are also
No. 9613, No. 45-24915, No. 45-25713, JP-A-Sho
No. 50-5102, No. 50-84302, No. 50-84303, No.
The azide group-containing polymers described in Patent Publications No. 53-12984 are also suitable. These photosensitive azide compounds are preferably used together with a polymer compound as a binder. Preferred binders include alkali-soluble resins, such as natural resins such as silica and rosin, novolak-type phenolic resins such as phenol formaldehyde resins and m-cresol formaldehyde resins, and polyacrylic acid, polymethacrylic acid, methacrylic acid-styrene resins, etc. Polymers, homopolymers of unsaturated carboxylic acids such as methacrylic acid-methyl acrylate copolymers, styrene-maleic anhydride copolymers, or copolymers of these with other copolymerizable monomers, polyvinyl acetate Examples include resins obtained by partially or completely saponifying aldehydes such as hydroxybenzaldehyde and carboxybenzaldehyde, and polyhydroxystyrene. It is preferable that the binder and the anionic polyurethane resin be contained in an amount ranging from about 10% by weight to about 90% by weight based on the total weight of the composition comprising the photosensitive azide compound. The composition comprising the photosensitive azide compound may further contain dyes and pigments, plasticizers such as phthalates, phosphoric esters, aliphatic carboxylic esters, glycols, and sulfonamides, such as Michler's ketone, 9-fluorenone, 1 -Nitropyrene, 1,8-dinitropyrene, 2-chloro-
1,2-benzanthraquinone, 2-bromo-
1,2-benzanthraquinone, pyrene-1,6
Additives such as sensitizers such as -quinone, 2-chloro-1,8-phthaloylnaphthalene, and cyanoacridine can be added. (4) In the main chain or side chain of the polymer

[Formula] A composition consisting of a polymer compound containing a group as a photosensitive group in the main chain or side chain of the polymer.

〔Effect of the invention〕

By using the photosensitive composition of the present invention, it is possible to obtain a photosensitive lithographic printing plate which has excellent abrasion resistance and can be developed with an aqueous developer. The present invention will be illustrated below with reference to Examples, but the embodiments of the present invention are not limited thereto. Example 1 [Aqueous polyurethane resin synthesis] 80/20 tolylene diisocyanate (80% of 2.4 units, 20% of 2.6 units of tolylene diisocyanate) was placed in a four-necked flask equipped with a thermometer, condenser, stirring bar, and dropping funnel. Take 87g and dissolve 100g of polypropylene glycol (molecular weight 400) in acetone solution.
201g was added and reacted at 60°C for 3 hours with stirring to produce an NCO-terminated prepolymer. Then a chain extender A solution of 65 g dissolved in 35 g dimethylformamide was gradually added dropwise to the above prepolymer and reacted at 56° C. for 3 hours. After that, 40 dimethylamine aqueous solution
Add 70g and mix well, then add 200g of demineralized water.
After stirring for 30 minutes, a pale yellow transparent urethane aqueous solution was obtained. A 2S aluminum plate with a thickness of 0.3 mm is degreased by immersing it in a 10% aqueous solution of trisodium phosphate held at 80°C for 30 seconds, and the pumice slurry is poured onto the aluminum plate while being rubbed with a nylon brush. It was then etched with sodium aluminate at 60°C for 10 seconds, followed by washing with a 3% aqueous solution of sodium hydrogen sulfate. This aluminum plate was anodized in 20% sulfuric acid at a current density of 2 A/dm ² for 2 minutes, and in a subsequent step at 70°C for 2.5 min.
% sodium silicate aqueous solution for 1 minute, washed with water and dried. Subsequently, the following photosensitive solution was applied using a wheeler and dried at 100°C for 2 minutes. Methyl methacrylate/methacrylic acid (molar ratio
85/15, MEK solution, intrinsic viscosity at 30°C
0.166) 48g Trimethylolpropane triacrylate 48g 3-methyl-2-benzoylmethylenenaphtho[1,2-d]thiazole 5g Water-based polyurethane resin described in the synthesis example above 24g Phthalocyanine blue (CI.Blue#15) 3g Ethylene dichloride 500g Methyl 500 g of cellosolve acetate After drying, a 3% by weight aqueous solution of polyvinyl alcohol was applied to the surface of the photosensitive layer. The membrane weights after drying were 3 g/m ² and 1.5 g/m ² , respectively. This is called sample A. For comparison, the above photosensitive solution was coated and dried in the same manner except for the aqueous polyurethane resin, and a 3% by weight aqueous solution of polyvinyl alcohol was coated on the surface of the photosensitive layer. The membrane weight after drying is 3g/m ² and 1.5, respectively.
g/ ^m2 . This is called sample B. This photosensitive lithographic printing plate was exposed to 30 counts of light through a negative image film using a Nuark printer equipped with a 2KW metal halide lamp, and then developed. The developing machine used was manufactured by Fuji Photo Film Co., Ltd.
A PS processor 400S, a developing time of 30 seconds, and a developer having the following composition were used. Benzyl alcohol 10g Monoethanolamine 1g Triethanolamine 10g Sodium isopropylnaphthalene sulfonate 2g Pure water 1000ml In Sample A according to the present invention, the photosensitive layer was dissolved and a negative image was formed as in Sample B, which is a comparative example. After washing with water, a gum arabic solution of 14°Be' was applied to the plate surface and buff-dried. After storing the printing plate thus completed for 7 days, it was mounted on a Heidelberg GTO printing press and printed. After printing, the number of sheets printed until the ink density reaches a predetermined density (number of inked sheets) and the number of sheets printed until the printing plate wears out and the ink density becomes thinner (number of printed sheets) are as shown in Table 1. .

[Table] Sample A according to the present invention is sample B as a comparative example.
The results showed that the number of printed sheets was smaller and the number of printed sheets was longer than that of the previous method. Example 2 The following photosensitive solution was applied to the support used in Example 1 using a wheeler and dried at 100°C for 2 minutes. Acetone - naphthoquinone of pyrogallol resin -
1,2-diazide(2)-5-sulfonic acid ester (synthesis method is described in US Pat. No. 3,635,709, Example 1)
2.5g Cresol-formaldehyde resin (Hitanol #3110, manufactured by Hitachi Chemical Co., Ltd.) 4g Water-based polyurethane resin HYDRAN, HW-102
(Sold by Nippon Reichhold Co., Ltd.) 1.5g Oil Blue #603 (manufactured by Orient Chemical Industry Co., Ltd.)
0.4 g Methyl ethyl ketone 75 g Cyclohexanone 60 g The weight of the membrane after drying was 2.5 g/m ² . This is called sample C. For comparison, the aqueous polyurethane resin was removed from the above photosensitive solution, and cresol-
A photosensitive solution containing 5 g of formaldehyde resin was similarly applied and dried. The membrane weight after drying was 2.5 g/m ² . This is called sample D. Furthermore, for comparison, the same amount of Estan 5715 polyurethane resin (sold by BF Gridrich Co., Ltd.) disclosed in Japanese Patent Publication No. 49-36961 was used in place of the water-based polyurethane resin used in the photosensitive solution, and the same amount was applied and dried in the same manner. The membrane weight after drying was 2.5 g/m ² . This is called sample E. The photosensitive planographic printing plate made in this way is passed through a transparent positive film in a vacuum printing frame.
Exposure was performed for 30 seconds from a distance of 1 m using a Fuji Film PS light (equipped with a Toshiba metal halide lamp MU2000-2-OL type 3 kW light source, sold by Fuji Photo Film Co., Ltd.). Subsequently, the plate is immersed in a developer having the following composition:
I developed it. JIS No. 1 Sodium silicate 10g Sodium metasilicate 5g Pure water 180ml Sample C according to the present invention had a photosensitive layer dissolved and a positive image was formed in the same manner as Sample D, which is a comparative example, but in Sample E, the photosensitive layer did not dissolve and an image was formed. was not formed. After washing with water, a gum arabic solution of 14°Be' was applied to the plate surface and buff-dried. After storing the printing plate thus completed for 7 days, it was mounted on a Heidelberg GTO printing press and printed. The results of the number of inked sheets and the number of printed sheets are shown in Table 2.

[Table] Sample C according to the present invention is sample D as a comparative example.
The results showed that the number of printed sheets was smaller and the number of printed sheets was larger than that of . Example 3 The following photosensitive solution was applied to the support used in Example 1 using a wheeler and dried at 100°C for 2 minutes. 2-Hydroxyethyl methacrylate copolymer (used in Example 1 of U.S. Pat. No. 4,123,276) 0.67 g 2-methoxy-4-hydroxy-5-benzoylbenzene, a condensate of p-diazodiphenylamine and paraformaldehyde sulfonate
0.1g Water-based polyurethane used in Example 1 0.2g Oil Blue-#603 (manufactured by Orient Chemical Industry Co., Ltd.)
0.03 g 2-methoxyethanol 6 g Methanol 6 g Ethylene dichloride 6 g The weight of the film after drying was 2.1 g/m ² . This is called sample F. For comparison, a photosensitive solution containing 0.87 g of the 2-hydroxyethyl methacrylate copolymer except that the aqueous polyurethane resin was removed from the above photosensitive solution was coated and dried in the same manner. The weight of the membrane after drying was 2.1 g/m ² , which is designated as Sample G. The photosensitive lithographic printing plate made in this way was exposed in a vacuum printing frame through a transparent negative film for 50 seconds with a Fujifilm PS light (using a 2KW metal halide lamp) from a distance of 1m, as shown below. After immersing it in a developer for 1 minute at 25°C, the surface was lightly rubbed with absorbent cotton to remove the unexposed areas to obtain a lithographic printing plate. Sodium sulfite 3g Benzyl alcohol 30g Triethanolamine 20g Monoethanolamine 5g Perex NBL (sodium t-butylnaphthalene sulfonate, manufactured by Kao Atlas Co., Ltd.) 30g Water 1000ml Sample F according to the present invention is the same as Sample G, which is a comparative example. The photosensitive layer was dissolved and a negative image was formed. After washing with water, a gum arabic solution of 14°Be′ was applied to the plate surface and puff-dried. After storing the printing plate thus completed for 7 days, it was mounted on a Heidelberg GTO printing press and printed.
The results of the number of inked sheets and the number of printed sheets are as shown in Table 3.

[Table] Sample F according to the present invention is sample G of the comparative example.
The results showed that the number of printed sheets was smaller and the number of printed sheets was larger than that of .

Claims (1)

[Claims] 1. A photosensitive composition for a lithographic printing plate, comprising an anionic polyurethane resin having an anionic group selected from a ^-COO- group and ^a _-SO3- group.