JPS6252547A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having less tendencys for lowering the sensitivity and for increasing the sticking property immediately after the preparation of the photosensitive plate or after a lapse of time under heating it by incorporating a specific polymerizable compd. having an ethylenically unsatd. double bond and a sticking agent of the polymer soluble to an alkaline aqueous solution or capable of swelling to said solution and a photopolymerization initiator to the titled composition. CONSTITUTION:The titled composition comprises the polymerizable compd. (a) having the ethylenically unsatd. double bond, and sticking agent (b) of the polymer soluble to the alkaline aqueous solution or capable of swelling to said solution and the photopolymerization initiator (c) as main components. The component (a) comprises the compd. shown by the formula. The compounding ratio of the compd. (a) is 5-70wt%, preferably 20-50wt% on the weight basis of the whole composition. The component (a) comprises the compd. shown by the formula, and may be used said compd. together with a pentaerythritol tetraacrylate, a pentaerythritol triacrylate, a trimethylolpropane triacrylate, a dipentaerythritol hexaacrylate etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive resin composition useful for manufacturing plate surfaces of lithographic printing plates, etc. More specifically, the present invention provides a photosensitive resin composition mainly consisting of a polymer binder, a polymerizable compound, and a photopolymerization initiator, and by using a specific compound as the polymerizable compound, the plate surface of a lithographic printing plate can be improved. This invention relates to novel photosensitive resin compositions which have been improved to reduce or eliminate surface tackiness and provide products with excellent photosensitivity, thermal stability and storage stability when used in the production of products such as .

In particular, the present invention relates to a novel photosensitive resin composition that prevents increase in surface tackiness due to long-term storage or thermal aging.

[Conventional technology]

Generally, in order to produce a printing plate by a photoforming method, a photosensitive resin is usually laminated on a support such as an aluminum plate, and subjected to image-forming exposure and development.

[Problem that the invention seeks to solve]

In this case, if a solid polymerizable compound is used, the mobility of active radicals during image-forming exposure is low and chain reactions are difficult to occur, resulting in a disadvantage that the curing rate becomes extremely slow. Although it is possible to increase the curing speed to some extent by increasing the amount of the polymerizable compound added, the amount of addition also depends on the compatibility between the polymerizable compound and the polymer binder. Naturally, there are limits.

On the other hand, when a liquid polymerizable compound is used, the curing speed is increased, but the surface has a disadvantage of significant stickiness.

Means for Solving Problem C] The present inventors have conducted extensive research in order to obtain a photosensitive resin composition suitable for plate production that overcomes the above-mentioned drawbacks of conventional photosensitive resin compositions. As a result of stacking, by combining a polymer binder and a specific polymerizable compound, it has excellent thermal stability and storage stability, and sensitivity does not decrease even with heat aging and long-term storage, and the surface tackiness is reduced. It has been discovered that a new photosensitive resin composition can be obtained which provides a printing plate that does not increase, and the present invention has been completed based on this finding.

That is, the photosensitive resin composition of the present invention comprises a) a compound having a polymerizable ethylenically unsaturated double bond, b) an alkaline water-soluble or swellable polymer binder, and C) a photopolymerization initiator. In the photosensitive resin composition containing as a main component, the component (a) at least has the general formula (1): [in the formula R
is a hydrogen atom or a methyl group, and X is a linking group or an optionally substituted alkylene group, cycloalkylene group, or arylene group.

In the composition of the present invention, the proportion of the compound having a polymerizable ethylenically unsaturated double bond (component (a)) is in the range of 5 to 70% by weight, preferably 20 to 50% by weight based on the total composition. It is.

In the general formula (1), the alkylene group represented by Y is represented by the general formula +C[(d-, where n is from 1 to 12, preferably from 1 to 6). Specific examples include methylene, ethylene, propylene, and butylene.

The arylene group refers to an aromatic ring or a heteroaromatic ring with a divalent linking group attached, and typical examples include phenylene group, naphthylene group, etc.

The above alkylene group or cycloalkylene group may contain an unsaturated group, examples of which include ethylene and cyclohexene.

Further, the alkylene group may contain a heteroatom such as oxygen, sulfur, or nitrogen within the alkylene group. The alkylene group, cycloalkylene group, and arylene group may each have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, an aromatic group having 6 to 12 carbon atoms, and a substituent group having 1 to 6 carbon atoms. Examples include an alkoxy group having an alkyl group of 1 to 4, a halogen atom, a carboalkoxy group having an alkyl group having 1 to 4 carbon atoms, a carboxyl group, a methylene group, and the like.

As the component (a) of the composition of the present invention, the above general formula (1) is used.
In addition to the compound represented by, compounds such as pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, and dipentaerythritol hexaacrylate can be used in combination.

The proportion of the compound represented by general formula (1) in component (a) is suitably 20 to 100% by weight, preferably 30 to 100% by weight.

The compound having a polymerizable ethylenically unsaturated double bond, represented by the general formula (1), contained in the composition according to the present invention can be prepared by a known method, for example, as described in "Organic Functional Group. Prevaluation “Academic Press” (authored by R. 5adler) Or
ganic Functional Group1'r
eparation"Academic Press)
(1968) P246.

That is, it can be easily obtained by reacting pentaerythritol triacrylate or pentaerythritol trimethacrylate with the corresponding dicarboxylic acid chloride or disulfonyl chloride in the presence of a base catalyst.

Specific examples of compounds having polymerizable ethylenically unsaturated double bonds contained in the composition according to the invention include the following.

Compound No. -X-Y-X
The alkaline water-soluble or swellable polymeric binder contained in the composition according to the invention may be an addition polymer having a carboxylic acid in its side chain, such as a methacrylic acid copolymer (for example, a methacrylic acid copolymer). Copolymers of methyl methacrylate and methacrylic acid, copolymers of ethyl methacrylate and methacrylic acid,
Copolymers of allyl methacrylate and methacrylic acid, copolymers of butyl methacrylate and methacrylic acid, copolymers of ethyl acrylate and methacrylic acid, copolymers of methacrylic acid and styrene and methacrylic acid, etc.) , acrylic acid copolymer, copolymer of ethyl acrylate and acrylic acid, copolymer of butyl acrylate and acrylic acid,
Ethyl acrylate and sulfur.

copolymers with tyrene and acrylic acid, etc.), as well as itaconic acid copolymers, crotonic acid copolymers, partially esterified maleic acid copolymers, and similar acidic celluloses with carboxylic acids in their side chains. There are derivatives.

These high molecular weight polymers may be used alone as a binder, but two or more types of high molecular weight polymers that are compatible enough to not cause demixing during the manufacturing process from preparation of the coating solution to application and drying may be used. Molecular polymers can be mixed in appropriate ratios and used as binders.

The molecular weight of the high molecular weight polymer used as a binder varies widely depending on the type of polymer, but generally ranges from 5,000 to 5,000.
A value in the range of 2,000,000, more preferably 10,000 to 1,000,000 is suitable.

Particularly preferred among these are polymers containing double bonds in their side chains;
Those described in Japanese Patent Application Laid-Open No. 7-157198 and Japanese Patent Application Laid-Open No. 48-30504 can be advantageously used. The amount of polymer binder is 20-95% by weight based on the total composition
, preferably from 50 to 90% by weight.

The photopolymerization initiator contained in the composition of the present invention includes U.S. Pat. No. 2,367,661 and U.S. Pat.
.
．． Aromatic acyloin compounds substituted with alpha-hydrocarbons as described in US Pat. No. 512, U.S. Pat.
．． No. 127, U.S. Patent No. 2.951.758, polynuclear quinone compounds described in each specification, U.S. Patent No. 3.5
49,367, triarylimidazole dimer/p-aminophenyl ketone combinations, trihalomethyl-3-)lyazine compounds described in U.S. Pat. No. 4,239,850. , acridine and phenazine compounds described in U.S. Pat. No. 3,751.259, U.S. Pat. No. 4.21
The oxadiazole compound described in the specification of No. 2.970 is included, and the amount used is about 0.
5-15% by weight, more preferably 2-10% by weight is suitable.

It is advantageous to add a negative-acting diazo resin to the composition of the present invention in order to improve adhesion to the printing plate support or to improve printing durability.

Suitable negative-acting diazo resins include those that are substantially water-insoluble and soluble in organic solvents. Specific examples of such diazo resins include 4-diazo-diphenylamine and -diazo 4-N.

N-dimethylaminobenzene, 1-diazo-4-N,N
-diethylaminobenzene, ■-diazo4-N-ethyl-N-hydroxyethylaminobenzene, 1-diazo-4-N-methyl-N-hydroxyethylaminobenzene, ■-diazo2゜5-jethoxy-4-benzoylaminobenzene , l-diazo-4-N-benzylaminobenzene, 1-diazo-4-N, N-dimethylaminobenzene, 1-diazo-4-morpholinobenzene, 1-
Diazo-2,5-dimethoxy-4-p-)lylmercabutobenzene, 1-diazo-2-ethoxy-4-N,N-
Dimethylaminobenzene, p-diazo-dimethylaniline, 1-diazo-2,5-dibutoxy-4-morpholinobenzene, 1-diazo-2,5-jethoxy-4-morpholinobenzene, ■-diazo2.5- Dimethoxy-4-morpholinobenzene, 1-diazo-2,5-jethoxy-4-morpholinobenzene, 1-cya/-2
, 5-jethoxy-4-p-)lylmercabutobenzene, ■-diazo-3-ethoxy-4-N-methyl-N-benzylaminobenzene, 1-diazo-3-chloro-4-
N,N-diethylaminobenzene, 1-diazo-3-methyl-4-pyrrolidinobenzene, 1-diazo-2-chloro-4-N,N-dimethylamino-5-methoxybenzene, 1-diazo-3-methoxy -4-pyrrolidinobenzene, 3-methoxy-4-diazodiphenylamine, 3-
Diazo monomers such as ethoxy-4-diazodiphenylamine, 3-(n-propoxy)-4-diazodiphenylamine, 3-(isopropoxy)-4-diazodiphenylamine and formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde. or a condensing agent such as benzaldehyde in a molar ratio of 1:1 to 1:0.5, preferably 〇, 8.
~l: It is a reaction product of a condensate obtained by condensing o, 6 in a conventional manner and an anion. Anions include tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitroortho-toluenesulfonic acid,
5-sulfosalicylic acid, 2.5-dimethylbenzenesulfonic acid, 2゜4.6-1-dimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2- Examples include fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, -naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and para-toluenesulfonic acid. Among these, phosphorus hexafluoride, alkyl aromatic sulfonic acids such as triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid are particularly preferred.

The amount of these diazo resins added to the total composition is 1 to 3
0% by weight, more preferably 3 to 15% by weight.

In addition to the above, it is preferable to add a thermal polymerization inhibitor, such as hydroquinone, p-methoxyphenol,
Di-t-butyl-p-cresol, pyrogallol, t-
Butylcatechol, benzoquinone, 4.4'-thiobis(3-methyl-6-butylphenol), 2.2'
-Methylenebis(4-methyl-6-t-butylphenol), 2-mercaptobenzimidazole, etc. are useful, and in some cases, dyes or pigments and pH indicators etc. are added as printing agents for the purpose of coloring the photosensitive layer. be able to.

Furthermore, phosphoric acid, phosphorous acid,
Tartaric acid, citric acid, malic acid, dipicolinic acid, polynuclear aromatic sulfonic acid and its salts, sulfosalicylic acid, etc. can be added as necessary. It is also useful to add waxes such as higher fatty acids.

In order to prepare a lithographic printing plate using the above-mentioned photosensitive composition, for example, 2-methoxy, shetanol, 2-methoxyethyl acetate, propylene glycol monomethyl ether, 3-methoxypropanol, 3-methoxypropyl acetate can be used. , methyl ethyl ketone, ethylene dichloride, etc. alone or in a mixed solvent of an appropriate combination thereof, and coated on the support. The coating amount is about 0.1 g/m2 to about 1 g/m2 after drying.
A range of 0 g/m2 is suitable, more preferably 0
．． 5-5 g/m2.

The supports used for this purpose are dimensionally stable plates. Such dimensionally stable plates include those conventionally used as supports for printing plates, such as paper, laminated plastics (e.g. polyethylene, polypropylene, polystyrene, etc.). sheets of metal such as aluminum (including aluminum alloys), zinc, copper, etc., such as heptalulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene Films of plastics such as terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc., paper or plastic films laminated or vapor-deposited with metals such as those mentioned above (included). Among these supports, aluminum plates are It is particularly preferred because it is extremely dimensionally stable and inexpensive.Furthermore, a composite sheet in which an aluminum sheet is bonded to a polyethylene terephthalate film as described in Japanese Patent Publication No. 18327/1983 is also preferred.

In addition, in the case of a support having a metal surface, especially aluminum, surface treatments such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate, etc., or anodization treatment are performed. Preferably. In addition, as described in U.S. Pat.
As described in Japanese Patent No. 7-5125, an aluminum plate which is anodized and then immersed in an aqueous solution of an alkali metal silicate is also preferably used. The above-mentioned anodizing treatment may be carried out by electrolysis using an aqueous or non-aqueous solution of an inorganic acid such as phosphoric acid, chromic acid, sulfuric acid, or boric acid, or an organic acid such as oxalic acid or sulfamic acid, or a salt thereof alone or in combination of two or more. This is carried out by passing an electric current through a liquid using an aluminum plate as an anode.

Also effective is silicate electrodeposition as described in US Pat. No. 3,658,662.

Furthermore, Japanese Patent Publication No. 46-27481, Japanese Patent Publication No. 52-5
Also useful is a surface treatment that combines a support subjected to electrolytic duplexing and the above-mentioned anodic oxidation treatment and sodium silicate treatment as disclosed in JP-A-8602 and JP-A-58-30503.

Furthermore, it is also preferable to use brush grain, electrolytic duplex, anodic oxidation, and sodium silicate treatment as disclosed in Japanese Patent Application Laid-Open No. 56-28893.

Furthermore, after these treatments, it is also suitable to undercoat with a water-soluble resin such as polyvinyl 7-osphonic acid, polymers and copolymers having sulfonic acid groups in their side chains, polyacrylic acid, and the like.

These hydrophilic treatments are performed not only to make the surface of the support hydrophilic, but also to prevent harmful reactions with the photosensitive composition provided thereon, and to improve the adhesion with the photosensitive layer. This is done for the purpose of improving the quality of life.

On the layer of the photosensitive composition provided on the support, a material with excellent oxygen barrier properties such as polyvinyl alcohol, acidic cellulose, etc. is used to completely prevent the polymerization inhibition effect caused by oxygen in the air. A protective layer made of polymer may also be provided. A method for applying such a protective layer is described in, for example, U.S. Pat.
-49729 specification in detail.

A photosensitive plate on which the photosensitive composition of the present invention is provided on a support is imagewise exposed using a light source rich in ultraviolet rays such as a metal halide lamp or a high-pressure mercury lamp, and then treated with a developer to remove any remaining photosensitive layer. A lithographic printing plate is prepared by removing the exposed area and finally applying a gum solution. Preferred as the developer is an alkaline aqueous solution containing a small amount of an organic solvent such as benzyl alcohol, 2-7 enoxyethanol, or 2-butoxycetanol.
175,171 and 3,615.480. Furthermore, JP-A-5
No. 0-26601, Special Publication No. 56-39464, No. 56
The developing solutions described in each publication of No. 42860 are also excellent as developing solutions for photosensitive printing plates prepared using the composition of the present invention.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Examples.

Note that % indicates weight %.

Synthesis Example 1 Synthesis of Compound (4) Pentaerythritol triacrylate (Toagosei M
2O3) and 14 g of triethylamine in 150 mI of acetonitrile! dissolved in. While cooling with water, 23.6 g of glutaric acid chloride was added dropwise over 17 minutes, stirring was continued for 20 minutes, and further stirring was continued for 3 hours at room temperature. The reaction solution was poured into 500 ml of water and extracted with ethyl acetate. The extract was washed successively with an aqueous sodium bicarbonate solution and a saline solution, and then dried using magnesium sulfate. The extract was filtered and ethyl acetate was distilled off under reduced pressure to yield 52 gf8 of compound (4). Compound (4) was analyzed by GPC (HL, C-8021R manufactured by Toyo Soda Kogyo@) using T I-I F as a solvent, and a large peak was observed at a polystyrene equivalent number average molecular weight (MN) of 890.

Note that the pentaerythritol triacrylate used as the raw material at this time was MN390.

Examples 1 to 5 Substrates were obtained by the method disclosed in JP-A-56-28893. That is, an aluminum plate with a thickness of 0.30, a nylon brush and a 400 mesh pumice stone with water%! After the surface was grained using the slurry, it was thoroughly washed with water. After etching by immersing it in 10% sodium hydroxide at 70° C. for 60 seconds, it was washed with running water, neutralized with 20% HNO3, and washed with water. 1 in a 1% nitric acid aqueous solution using a sinusoidal alternating current waveform under the condition of = 12.7 V.
Electrolytic surface roughening treatment was carried out with an amount of electricity of 60 ron/dm2.

When the surface roughness was measured, it was 0.6μ (Ra display)
Met. Subsequently, it was immersed in a 30% 82304 aqueous solution and treated with desmart at 55°C for 2 minutes, followed by 20% H
It was anodized in a 2SO4 aqueous solution at a current density of 2 A/dm' for 2 minutes to a thickness of 2.7 g/m2. Thereafter, it was immersed in a 2.5% sodium silicate aqueous solution at 70° C. for 1 minute, washed with water, and dried.

The following photosensitive solution was prepared.

Photosensitive liquid Compound of Table 1 20g Photopolymerization initiator dioyl blue #603 with the following structure 1. Og(
Orient Chemical Industry GL) F17? (Manufactured by Dainichi Ink σ Kiku) 1.
After filtering 150 g of Og methyl alcohol and 300 g of methyl ethyl ketone, the photosensitive solution was coated onto the substrate using a spin coating machine so that the weight after drying was 2.0 g/m'. Drying is 10
The test was carried out at 0° C. for 2 minutes to obtain samples of Examples 1 to 5.

As comparative examples, the compounds of Table 1 were removed from the photosensitive solutions of Examples, and pentaerythritol tetraacrylate was used instead, and the sample of Comparative Example 1 was used. I created a sample.

In order to compare the decrease in sensitivity and increase in tackiness after heating of these samples, the samples immediately after preparation and the samples after preparation, 6
A comparison was made with a sample heated at 0°C for 3 days.

The tackiness was measured before exposure and development, and the sensitivity was compared by the number of steps when exposure and development was performed under the following conditions. Table 1 shows the results.
Shown below.

Fuji PS step guide (ΔD=0.1
5) with a gray scale in which the transmission density changes discontinuously), and the printer PT26V2UPN manufactured by Nuark, USA.
Exposure was performed using S (light source: 2 kW metal halide lamp).

Development conditions After immersing in the following developer for 50 seconds, the surface was lightly rubbed with absorbent cotton to remove unexposed areas.

Developer Sodium Sulfite 5g Benzyl Alcohol Jetanolamine 5g Isopropyl Naphthalene 7 12g Sodium Sulfonate Pure Water 1
000g Table 1 0... Not sticky at all.

Δ...Slightly sticky.

X: Sticky enough to be unusable.

〔Effect of the invention〕

A photosensitive plate using the photosensitive resin composition of the present invention exhibits an excellent effect that there is no decrease in sensitivity or increase in tackiness immediately after preparation or after heating.

Claims (1)

[Scope of Claims] A photosensitive resin composition containing a) a compound having a polymerizable ethylenically unsaturated double bond, b) an alkaline water-soluble or swellable polymer binder, and c) a photopolymerization initiator. In the product, the component (a)
There is at least a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (1) [In the formula, R is a hydrogen atom or a methyl group, and X is ▲ mathematical formula,
Photosensitivity characterized by containing a compound represented by ▼ or ▲ where there are chemical formulas, tables, etc., and Y is a cycloalkylene group or arylene group containing no atoms. Resin composition.