JP2745928B2 - Photosensitive resin printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin printing plate, particularly an aqueous resin (a resin dissolved in a solvent containing water as a main component).
The present invention relates to a photosensitive resin printing plate for performing coating by a printing method.

As is well known, in recent years, with the upscaling of printed materials, a varnish is applied (so-called varnishing or burnishing) after ordinary color printing for so-called polishing of the surface of the printed materials and for enhancing the water resistance and weather resistance of the printed materials. In recent years, varnishing only a part of a pattern (referred to as partial varnishing or spot burnishing) is rapidly spreading. Another tendency is that the characteristics of varnishes change from oil-based varnishes, which dissolve resins in conventional organic solvents, to global pollution-free or global environmental protection, and dissolve resins in water-based solvents. It can be mentioned that it is rapidly migrating to an aqueous varnish. On the other hand, other than the aqueous varnished printing, the field is rapidly expanding to the field of aqueous resin coating.

[0003]

2. Description of the Related Art In these applications, a photosensitive rubber printing plate or an alcohol washable photosensitive resin plate is usually used. In the case of a photosensitive rubber printing plate, a human body is required in a washing process at the time of plate making. And the problem of using organic solvents that have a negative effect on the global environment.Also, even in the case of alcohol-washable photosensitive resin plates, there is a drawback in that highly flammable ethyl alcohol is used in the washing process,
It is a major hindrance to its spread.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and has as its object to provide high image reproducibility, printability and good water developability. Another object of the present invention is to provide a photosensitive resin printing plate that can withstand coating by an aqueous resin printing method.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
Photosensitive resin printing using a photosensitive resin composition comprising (a) a soluble polymer, (b) a photopolymerizable unsaturated compound having an ethylenic double bond in the molecule, and (c) a photopolymerization initiator as essential components. In the printing plate, the soluble polymer is mainly composed of a water-soluble polyamide and an alcohol-soluble polyamide, and the ratio of the soluble polymer in the photosensitive resin composition is not less than 20% by weight and not more than 70% by weight. The proportion of the water-soluble polyamide in the polymer is 30% by weight or more,
80% by weight or less, and the proportion of the photopolymerizable unsaturated compound in the photosensitive resin composition is 30% by weight or more and 70% by weight or more.
This is achieved by a photosensitive resin printing plate characterized by the following.

[0006] The soluble polymer in the present invention includes:
Although polymers soluble in alcohol and / or water can be used, it is preferable to mainly use polyamide from the viewpoint of compatibility between the polymers or between the polymer and the photopolymerizable unsaturated compound.

In the present invention, the term "water-soluble" means having a property of dissolving and / or dispersing in water. For example, when a polyamide formed into a film is immersed in water or warm water and rubbed with a brush or the like, the polyamide is completely coated. The film loses or disintegrates due to elution or partial elution, or when the polyamide swells and separates and disperses in water. Specifically 0.5mm
After forming the polyamide into a thick film,
For 1 hour. Film completely dissolved or poly
If more than 200% by weight of water swells
Classify as water soluble. On the other hand, alcohol solubility is low
Soluble in grade alcohols (methanol, ethanol)
Refers to quality. Specifically, a 0.5 mm thick film
After molding amide, immerse in ethanol at 25 ° C for 1 hour
I do. Complete dissolution of the film or against the polymer
Alcohol is acceptable if more than 200% by weight of water swells
Classify as soluble. Here, water soluble and alcohol
For those having both properties of solubility
Classify.

The present invention has found a photosensitive resin composition which can be developed with neutral water by utilizing such a characteristic property of polyamide and can be applied to aqueous resin coating or printing.

The water-soluble polyamide used in the present invention includes all of those conventionally proposed. For example, polyamides containing a sulfonic acid group or a sulfonate group obtained by copolymerizing sodium 3,5-dicarboxybenzenesulfonate as disclosed in JP-A-48-72250, 49-43465, which has an ether bond obtained by copolymerizing any one of dicarboxylic acids, diamines and cyclic amides having an ether bond in a molecule as disclosed in JP-A-49-43465. Polyamide, N, N'- as disclosed in JP-A-50-7605
Polyamides containing basic nitrogen obtained by copolymerizing di (γ-aminopropyl) piperazine and the like, and polyamides obtained by quaternizing these polyamides with acrylic acid or the like, have been proposed in JP-A-55-74537. Molecular weight 1
Copolymerized polyamide containing 50 to 1500 polyether segments, and ring-opening polymerization of α- (N, N′-dialkylamino) -ε-caprolactam or α-
Polyamides obtained by ring-opening copolymerization of (N, N′-dialkylamino) -ε-caprolactam and ε-caprolactam are exemplified.

[0010] Among these water-soluble polyamides, copolymerized polyamides containing a polyether segment having a molecular weight of 150 to 1500, more specifically, a polyether segment having an amino group at a terminal and having a molecular weight of 150 to 1500 are preferred.
A copolymer polyamide containing 1500 to 30% by weight of a structural unit composed of polyoxyethylene and an aliphatic dicarboxylic acid or a diamine is preferably used.

These water-soluble polyamides may be used alone or as a mixture of two or more.

The alcohol-soluble polyamide used in the present invention includes a dibasic fatty acid and a diamine;
-Amino acids, lactams or linear polyamides synthesized by known methods from lactams or derivatives thereof,
Not only homopolymers but also copolymers and block polymers can be used. Polyamide having a substituent on a carbon atom constituting the main chain or on a nitrogen atom can also be used,
Further, a polyamide containing a bond other than CC and -CN-CO- in the main chain may be used. The following are typical examples. Nylon 3, 4, 5,
6, 8, 11, 12, 13, 66, 610, 6/10,
13/13, polyamide from meta-xylylenediamine and adipic acid, trimethylhexamethylenediamine, or polyamide from isophoronediamine and adipic acid, ε-caprolactam / adipic acid / hexamethylenediamine / 4,4'-diaminodicyclohexylmethane Polymerized polyamide, ε-caprolactam / adipic acid /
Hexamethylenediamine / 2,4,4′-trimethylhexamethylenediamine copolymerized polyamide, ε-caprolactam / adipic acid / hexamethylenediamine / isophoronediamine copolymerized polyamide, polyamide containing these components, N-methylo- And N-alkoxymethyl derivatives.

These alcohol-soluble polyamides may be used alone or in combination of two or more.

The amount of the soluble polymer used must be 20% by weight or more and 70% by weight or less in the photosensitive resin composition, preferably 30% by weight or more and 6% by weight or less.
0% by weight or less.

When the ratio of the soluble polymer in the photosensitive resin composition is less than 20% by weight, the surface of the obtained composition is soft and tacky, so that when used as a printing plate, the original film is not used. Uniform vacuum contact cannot be achieved on the photosensitive layer, making uniform printing of the image impossible. In addition, it takes a lot of effort to remove the original film, and the film surface of the original film is often damaged. Further, since the amount of the photopolymerizable monomer becomes too large, the hardness of the printing plate after the exposure and plate making becomes high, and cracks occur on the plate surface during printing, so that a problem such that a good printed matter cannot be obtained occurs.

On the other hand, when the ratio of the soluble polymer in the photosensitive resin composition exceeds 70% by weight, the printing plate obtained because of the shortage of the absolute amount of the polymerizable monomer required for the photopolymerization reaction. Has a very low crosslinked structure density. For this reason, the water resistance of the photoinsolubilized portion is inferior, image reproducibility is deteriorated, and furthermore, the swelling of the plate surface in aqueous resin coating or aqueous varnish printing becomes large, so that good printed matter cannot be obtained. This can cause trouble.

The proportion of the water-soluble polyamide in the soluble polymer must be 30% by weight or more and 80% by weight or less, preferably 40% by weight or more and 70% by weight or less.
It is as follows.

When the proportion of the water-soluble polyamide contained in the soluble polymer is less than 30% by weight, the solubility of the photosensitive resin composition in neutral water is remarkably reduced, and a long time is required for water development. Or unresolved matter remains in the plate material after development. When the amount of the water-soluble polyamide is more than 80% by weight, the swelling property with respect to water is increased, and the solvent resistance of the printing plate with respect to the aqueous resin or the aqueous varnish ink is reduced. Absent.

The proportion of the alcohol-soluble polyamide in the soluble polymer is preferably from 20% by weight to 70% by weight, more preferably from 30% by weight to 60% by weight.
% By weight or less.

When the proportion of the alcohol-soluble polyamide contained in the soluble polymer component is less than 20% by weight, the water resistance of the resulting photosensitive resin plate material is remarkably reduced. In printing with water or an aqueous varnish ink, the swelling of the printing plate becomes large, which causes a destruction of the relief and a decrease in print quality. Also,
If the content of the alcohol-soluble polyamide in the soluble polymer component exceeds 70% by weight, the solubility of the photosensitive resin composition in water is reduced, making neutral water development practically impossible.

As the soluble polymer, a polymer other than the polyamide can be used in combination with the above-mentioned soluble polyamide. Examples of polymers other than polyamide usable in the present invention include, for example, alcohol-soluble polymers such as poly (meth) acrylate, polyvinyl butyral, epoxy resin, phenol resin, polyvinyl acetate, and urea. And melamine resin, methyl vinyl ether, acid anhydride, acid anhydride and the like. Examples of the water-soluble polymer include polyvinyl alcohol, polyvinyl pyrrolidone, cellulose and the like, but are not limited thereto.

When these polymers are used in combination with the above polyamide, if the amount is too large relative to the amount of the polyamide component, the compatibility of the photosensitive resin composition may be reduced, which may be a factor of impairing the photosensitive characteristics. For this reason, it is preferable that the amount of these polymers used be 20% by weight or less of the polyamide component.

The photopolymerizable unsaturated compound having an ethylenic double bond in the molecule used in the present invention includes:
Known ones are used, and those having a certain degree of compatibility with the soluble polymer are used.

Specifically, the following are mentioned. 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
Monoacrylates having a hydroxyl group such as -hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl acrylate and 3-chloro-2-hydroxypropyl methacrylate And monomethacrylate. Polyhydric acrylates and polyhydric methacrylates obtained by reacting a polyhydric alcohol such as ethylene glycol with an unsaturated carboxylic acid such as acrylic acid or methacrylic acid. Glycidyl acryle
And unsaturated epoxy compounds such as glycidyl methacrylate, 3,4-epoxycyclohexyl acrylate, and 3,4-epoxycyclohexyl methacrylate. Polyhydric acrylates and methacrylates having a hydroxyl group which are synthesized by the reaction of a polyvalent glycidyl ether such as ethylene glycol diglycidyl ether and an unsaturated carboxylic acid such as acrylic acid and methacrylic acid. Polyhydric acrylates and methacrylates having a hydroxyl group, which are synthesized by reacting an unsaturated epoxy compound such as glycidyl methacrylate with an unsaturated carboxylic acid such as acrylic acid or methacrylic acid. Condensation of acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, diacetoneacrylamide, methylenebisacrylamide, N-methylolacrylamide or N-methylolmethacrylamide with polyhydric alcohol Acrylamide-based photopolymerizable monomers such as polyhydric acrylamide and polyhydric methacrylamide obtained by the reaction, and the like, preferably acrylic or methacrylic esters having a hydroxyl group and acrylic or methacrylamides are used.

The proportion of the photopolymerizable unsaturated compound in the photosensitive resin composition must be in the range of 30 to 70% by weight.

When the proportion of the photopolymerizable unsaturated compound in the photosensitive resin composition is less than 30% by weight, the density of the crosslinked structure formed by photopolymerization becomes insufficient, so that the water-based varnish containing water as a main component is not used. It easily swells in the diluting solvent, and swelling and destruction of the solid portion during printing and poor printing are likely to occur. In addition, sufficient image reproducibility cannot be obtained due to insufficient crosslinking density. In addition, if a photopolymerizable unsaturated compound having higher crosslinkability is used to obtain high quality image reproducibility, the plate hardness of the printing plate material is increased, and the ink adhesion to a printing material is reduced, and a good printed material is obtained. become unable. Conversely, if the proportion of the photopolymerizable unsaturated compound in the photosensitive resin composition exceeds 70% by weight, the density of the crosslinked structure generated by photopolymerization becomes excessive, so that the plate-made relief is very brittle. This causes problems such as cracks in the relief during printing.

As the photopolymerization initiator in the present invention, all conventionally known photopolymerization initiators can be used. For example, there are benzoin alkyl ethers, benzophenones, anthraquinones, benzyls, acetophenones, diacetyls and the like. These photopolymerization initiators can be used in the range of 0.01 to 10% by weight based on the total amount of the photosensitive resin composition.

As a compatibilizer between the soluble polymer and the photopolymerizable unsaturated compound in the photosensitive resin composition of the present invention, ethylene glycol, diethylene glycol, triethylene glycol, glycerin, trimethylolpropane, Polyhydric alcohols such as trimethylolethane, N-ethyl-
It is also possible to add p-toluenesulfonamide, N-butylbenzenesulfonamide, N-methylbenzenesulfonamide and the like. These polyhydric alcohols and sulfonamide compounds have the effect of increasing the flexibility of the photopolymerized portion and preventing the occurrence of relief cracks. Such a polyhydric alcohol or sulfonamide compound can be used in an amount of 30% by weight or less based on the photosensitive resin composition.

In order to improve the thermal stability of the photosensitive resin composition of the present invention, a conventionally known polymerization inhibitor can be used. Preferred thermal polymerization inhibitors include phenols, hydroquinones, catechols and the like. These thermal polymerization inhibitors are used in an amount of 0.0
It can be used in the range of 01 to 5% by weight. Also,
Dyes, pigments, surfactants, defoamers, ultraviolet absorbers, fragrances and the like can be added.

The method for producing the composition of the present invention includes:
For example, a soluble polymer is heated and dissolved in a mixed solvent of water / alcohol, and then an unsaturated epoxy compound is added to cause an addition reaction to the polymer. Then, it is common to add a photopolymerizable unsaturated compound, a photopolymerization initiator, and a heat stabilizer, stir and mix well. Thus, a photosensitive resin solution is obtained.

In order to form a photosensitive layer from the above-mentioned mixed solution, for example, it is possible to distill most of the solvent and then heat it into a molten state to extrude it onto a support. Also, a photosensitive sheet is made by a dry film forming method, and this sheet is formed.
It is also possible to form a photosensitive layer by adhering a photosensitive layer on a support. Further, the photosensitive layer can be obtained by dry film formation directly on the support. As the support, a metal plate such as steel, stainless steel, aluminum, or copper, a plastic sheet such as a polyester film, or a synthetic rubber sheet such as a styrene-butadiene copolymer is used. The photosensitive layer is preferably formed to a thickness of 0.01 to 10 mm.

In order to form a printing plate using the photosensitive resin composition of the present invention, a negative or positive original film is brought into close contact with the photosensitive layer prepared as described above, and a wavelength of usually 300 to 400 mμ is applied. High pressure mercury lamp,
Ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, and chemical lamps are used to irradiate ultraviolet rays to make them insoluble by photopolymerization. Then, the unpolymerized portion is eluted into water by a spray type developing device or a brush type developing device using neutral water to form a relief on the support.

The photosensitive resin composition of the present invention has good water developability and high image reproducibility, and can provide a photosensitive resin plate material which can be used for aqueous resin coating.
In particular, in printing using an aqueous varnish, it has good durability at the time of printing and can give a good gloss of the printed matter surface.

This is because the photosensitive resin composition itself can be developed with water by adding a water-soluble polyamide to the soluble polymer in a certain ratio, and furthermore, an alcohol-soluble polyamide which is a water-insoluble soluble polymer is contained. Therefore, the resistance to an aqueous varnish ink obtained by dissolving a resin in a solvent containing water as a main component is remarkably improved. Further, by mainly using polyamide as the soluble polymer, the toughness of this polymer is combined with the improvement of the water resistance of the photosensitive resin plate material, so that the durability in the aqueous resin coating can be further improved. .

Further, by adding an unsaturated epoxy compound to the terminal carboxyl group of the soluble polymer, the polymer itself has photopolymerizability, and thus is formed by a photopolymerization reaction with a photopolymerizable unsaturated compound. -The network structure of the leaf is formed at a higher density, the resulting relief has good water resistance and can maintain a high level of image reproducibility, and the relief is tough during printing due to its toughness. Thus, problems such as cracks can be prevented.

The photosensitive resin composition of the present invention exhibits the best effect when used as a relief printing plate material, but can also be used as a lithographic printing material, an intaglio printing material or a stencil printing material.

[0037]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Toray Nylon CM- as an alcohol-soluble polyamide
8000, and a polyamide having a number average molecular weight of 6
Acrylonitrile was added to both ends of polyoxyethylene No. 00, and hydrogen reduction was performed to obtain 55 parts by weight of an equimolar salt of α, ω-diaminopolyoxyethylene and adipic acid, 25 parts by weight of ε-caprolactam, And 20 parts by weight of an equimolar salt of hexamethylenediamine and adipic acid are melt-polymerized under ordinary conditions to give a relative viscosity (1 g of polymer dissolved in 100 ml of chloral hydrate and measured at 25 ° C., the same applies hereinafter) of 2.50. 52 parts of a polyamide having the following formula: ethanol / water =
80 ° C to 160 parts by weight of a 60/40 (parts by weight) mixed solvent
And dissolved by heating.

Then, 2 parts by weight of glycidyl methacrylate was added and reacted at 80 ° C. for 1 hour to react the epoxy group of glycidyl methacrylate with the amino group and carboxyl group at the terminal of the polyamide. A methacryloyl group was introduced at the terminal. Then, propylene glycol diglycidyl ether was used as the polymerizable unsaturated compound.
20 parts by weight of an addition reaction product of ter and acrylic acid, 50 an addition reaction product of xylylenediamine and glycidyl methacrylate
Parts by weight, 30 parts by weight of β-hydroxyethyl-β′-acryloyloxyethyl phthalate, 2 parts by weight of dimethylbenzylketal as a photoinitiator, hydroquinone monomethyl ether as a thermal polymerization inhibitor 0.1 part by weight. One part by weight and 3 parts by weight of sodium methylenebisnaphthalenesulfonate were added and mixed well with stirring.

The photosensitive resin composition thus obtained was coated with an epoxy-based adhesive and cured to form a 250 μm-thick steel substrate. Delayed. Next, the hot air oven at 60 ° C.
After a period of time, the solvent was completely removed. A thin solvent of ethanol / water = 80/20 (weight ratio) was applied to the surface of the photosensitive layer thus obtained, and then a 100 μm thick polyester film matted by chemical etching was pressed. A cover film was attached.

After storing this plate material in a dark place for 10 days, the cover film of the plate material was peeled off, and a gray scale negative film for sensitivity measurement and a negative film (133) for evaluating image reproducibility were obtained.
Lines, 3%, 5%, 10% halftone dots, 200μ diameter and 30
(Independent points of 0 μ, fine lines with widths of 50 μ and 70 μ) were brought into close contact with each other under vacuum and exposed to a high-pressure mercury lamp for 2 minutes. Then 30
When the development was carried out under the condition of a water pressure of 3 kg / cm ² using a spray type developing device containing neutralized water at a temperature of 4 ° C., the non-image area was completely eluted in water in 4 minutes, and a relief image was obtained. Could be obtained. As a result of evaluating the obtained relief, it was found that the gray scale remained up to 17 steps and was very high sensitivity. It was confirmed that the image portion was sharply reproduced up to a fine portion such as a 3% halftone dot, a 200 μ independent point, and a 50 μ fine line.

A printing test was carried out on the thus obtained printing plate using a varnishing ink "LITHCOAT" 300A varnish (Toyo Ink Products). Was done. Also, 5
Printing was performed up to 100,000 passes, but no problems such as peeling of the relief and generation of cracks occurred.

Example 2 "Toresin" MF- as an alcohol-soluble polyamide
30 (N-methoxymethylated product of Nylon 6; Teikoku Chemical Co., Ltd.), 24 parts by weight, Toray Nylon CM-4000, 15 parts by weight, water-soluble polyamide, polyoxyethylene with a number average molecular weight of 400 Polyamide obtained by melt-polymerizing 50 parts by weight of equimolar salt of α, ω-diaminopolyoxyethylene and adipic acid and 50 parts by weight of ε-caprolactam under ordinary conditions by adding a nitrile and reducing it with hydrogen. 61 parts by weight were used. These three polymers were dissolved in 120 parts by weight of a mixed solvent of ethanol / water = 70/30 (weight ratio) by heating to 80 ° C. Next, 3 parts by weight of glycidyl methacrylate and 0.5 part by weight of triethanolamine were added to the solution and reacted for about 1 hour. Then, as a photopolymerizable unsaturated compound,
50 parts by weight of 2-acryloyloxyethyl-2-hydroxyethylphthalic acid and phenoxypolyethylene glyco-
20 parts by weight of luacrylate were added and mixed well with stirring. Further, 10 parts by weight of diethylene glycol, 1.5 parts by weight of benzoin methyl ether as a photoinitiator, and 0.01 parts by weight of hydroquinone as a heat stabilizer were added and sufficiently stirred and mixed.

The photosensitive resin solution thus obtained was previously coated with an epoxy-based adhesive to a thickness of 250.
The solution was cast on a .mu. steel plate so that the thickness after drying was 1300 .mu.m, and placed in a hot air oven at 60.degree. C. for 6 hours to completely remove the solvent. A thin solvent of ethanol / water = 70/30 (weight ratio) was applied to the surface of the photosensitive layer thus obtained, and then a 100 μm thick polyester film matted by chemical etching was pressed. A cover film was attached.

The plate material thus obtained was brought into vacuum contact with a gray scale negative film for sensitivity measurement and a negative film for evaluating image reproducibility used in Example 1, and exposed to an ultrahigh pressure mercury lamp for 1 minute. Subsequently, development was carried out using a brush type developing device containing neutral water at 25 ° C., and the non-image area was completely eluted in water in 4 minutes, so that a relief image could be obtained. As a result of evaluating the obtained relief, gray scale
It was found that up to 16 steps remained, indicating that the sensitivity was increased. Image area is 3% halftone dot, 200μ independent point,
It was confirmed that even a fine portion such as a 50 μ fine line was reproduced sharply.

A printing test was carried out using the thus obtained printing plate material. As a result, a printed product having a sharp print without thickening of the image was obtained. Printing was performed up to 300,000 passes, but no problem such as cracking of the plate material occurred. Furthermore, using the printing plate made with this plate material,
After normal color printing, printing was performed on the surface of the printed matter with the aqueous varnishing ink "AC Coat" PV500 (product of Sakata Inx), and a good printed matter having excellent gloss on the surface of the printed matter was obtained. Further, printing was performed up to 300,000 passes, but no problems such as chipping of the printing plate and blurring of the printed matter occurred at all. Example 3 Toray Nylon CM- as an alcohol-soluble polyamide
8000, and a polyamide having a number average molecular weight of 10 as a polyamide that can be dissolved or dispersed in 40 parts by weight of this polyamide and water.
Acrylonitrile was added to both ends of polyoxyethylene No. 00, and the resulting mixture was hydrogen-reduced. An equimolar salt of α, ω-diaminopolyoxyethylene and adipic acid was 65 parts by weight, and ε-caprolactam was 35 parts by weight. 60 parts by weight of a polyamide melt-polymerized under the following conditions: ethanol / water = 80
/ 20 (weight ratio) by heating at 80 ° C in a mixed solvent. Next, 1 part by weight of glycidyl methacrylate was added and reacted at 80 ° C. for 1 hour. The carboxyl group of the polyamide terminal disappeared from the analysis result by potentiometric titration,
It was found that an unsaturated bond was introduced into the polymer side chain by reacting with the epoxy group of glycidyl methacrylate. Next, as a photopolymerizable unsaturated compound, 30 parts by weight of polyethylene glycol diacrylate and an unsaturated compound 4 obtained by an addition reaction of glycidyl methacrylate and acrylic acid
0 parts by weight, 20 parts by weight of N-ethyl-p-toluenesulfonamide as a plasticizer, 3 parts by weight of benzyldimethylketal as a photoinitiator, and 0.1 part by weight of t-butylcatechol as a heat stabilizer. In addition, the mixture was sufficiently stirred and mixed.

The photosensitive resin solution thus obtained is dried on a polyester film substrate having a thickness of 185 μm, which is previously coated with a polyester adhesive and cured by heat and light. Was cast to 1300 μm. This was put in a hot air oven at 60 ° C. for 5 hours to completely remove the solvent. The plate material thus obtained was exposed to a chemical lamp for 4 minutes using the same negative film as in Example 1, and then developed with a neutral water brush developing device at a water temperature of 30 ° C. The development time required 4 minutes. When the obtained relief was examined, it was confirmed that the gray scale remained up to 16 steps, indicating high sensitivity.
It was found that the 0 μ fine line was reproduced without any problem.

Using the plate material, a varnishing ink "HYDLI"
When a printing test was performed using TH "2012-S (Dainippon Ink & Chemicals, Inc.), a printed matter having a thick printed image and a good surface gloss was obtained. Further, printing was performed up to 200,000 passes. No problems such as peeling of the relief and generation of cracks occurred.

Example 4 Toray Nylon CM- as an alcohol-soluble polyamide
9000 and CM8000 are used in combination. As polyamides which can be dissolved or dispersed in water at 10 parts by weight and 20 parts by weight, respectively, 30 parts by weight of ε-caprolactam, equimolar salt of hexamethylenediamine and adipic acid 3
6 parts by weight, 14 parts by weight of dimethyl isophthalate, 8 parts by weight of dimethyl 5-sodium sulfoisophthalate, 12 parts by weight of hexamethylenediamine and 8 parts by weight of water were stirred at 130 ° C. for 8 hours under a nitrogen stream, and then stirred at 270 ° C. for 5 hours. 70 parts by weight of the copolymerized polyamide obtained by the reaction was dissolved at 80 ° C. in 150 parts by weight of a mixed solvent of ethanol / water = 50/50 (weight ratio).

Next, as a photopolymerizable unsaturated compound, 2
-Hydroxyethyl methacrylate 80 parts by weight, N-methylol acrylamide 40 parts by weight, ethylene glycol
40 parts by weight of ludia acrylate were added. Further, 3 parts by weight of benzophenone as a photoinitiator and 0.01 parts by weight of phenothiazine as a heat stabilizer were added and mixed well with stirring. The photosensitive resin solution obtained in this manner was cast on an aluminum substrate coated with an epoxy adhesive so that the thickness after drying became 1000 μm, and was placed in a hot air oven at 60 ° C. for 3 hours. The solvent was removed.

After exposing the obtained plate material under the same conditions as in Example 1, development was carried out using a brush type developing device. Unexposed portions were completely removed in about 2 minutes. When the obtained relief was examined, the gray scale remained up to 17 steps, and high sensitivity was maintained. The relief is a sharp and completely reproduces 3% halftone dots, 200 μ independent points and 50 μ fine lines, and is subjected to a printing test using an aqueous varnishing ink “Aqua Pack Varnish” F-22 (manufactured by Toka Pigment Co., Ltd.). However, there were no problems such as peeling of the relief and cracking after 300,000 passes.

Example 5 "Toresin" MF- as an alcohol-soluble polyamide
30 (N-methoxymethylated modified product of Nylon 6; Teikoku Chemical Co., Ltd.), 30 parts by weight of Toray Nylon CM-4000, and N, N'-bis (γ-aminopropyl) piperazineazi 50 parts by weight of a paste and 50 parts by weight of ε-caprolactam were copolymerized, and 15 parts by weight of acrylic acid were added thereto, and 50 parts by weight of a quaternized polyamide was used by heating reaction. A mixed solvent of these polyamides in ethanol / water = 70/30 (weight ratio) 1
20 parts by weight and heated to 80 ° C. to dissolve. Then, 2 parts by weight of glycidyl methacrylate was added to the solution to prepare about 1 part.
Allowed to react for hours. Then, as a photopolymerizable unsaturated compound, 50 parts by weight of 2-acryloyloxyethyl-2-hydroxyethylphthalic acid and 50 parts by weight of phenoxypolyethylene glycol acrylate were added and thoroughly mixed. Further, N-butylbenzenesulfonamide 20
Parts by weight, benzyldimethylketal as photoinitiator
5 parts by weight and 0.01 part by weight of hydroquinone as a heat stabilizer were added and mixed well with stirring.

Next, the photosensitive resin solution was previously coated with a polyester-based adhesive and cured by heat and light.
It is cast on a 50 μm polyester film substrate so that the thickness (including the substrate) after drying becomes 1300 μm,
In a hot air oven for 4 hours to completely remove the solvent.
Ethanol / water = 70/30 on the surface of the obtained photosensitive layer.
After the solvent (weight ratio) was thinly applied, a 100 μm-thick polyester film matted by chemical etching was pressed and a cover film was mounted.

The plate material thus obtained was vacuum-contacted with a gray scale negative film for sensitivity measurement and a negative film for evaluating image reproducibility used in Example 1, and exposed to an ultra-high pressure mercury lamp for 1.5 minutes. Then, development was carried out using a brush type developing device filled with neutral water at 30 ° C. As a result, the non-image area was completely eluted in water in 5 minutes, and a relief image could be obtained. As a result of evaluating the obtained relief, it was found that the gray scale remained up to 16 steps, and the sensitivity was improved. It was confirmed that the image portion was sharply reproduced to a fine portion such as a 3% halftone dot, a 200 μ independent point, and a 50 μ fine line.

Further, when a printing test was carried out using this plate material, a sharp printed product without thickening of the image was obtained. Further, printing was performed up to 200,000 passes, but no problem such as generation of cracks in the plate material occurred. Further, using a printing plate made with this printing plate, after performing normal color printing, printing was performed on the surface of the printed material with an aqueous varnishing ink "AC Coat" PV500 (product of Sakata Inks). Good prints could be obtained. Further, printing was performed up to 200,000 passes, but no problems such as chipping of the printing plate and blurring of the printed matter occurred at all.

[0056]

Since the present invention is constructed as described above, it has excellent water developability and image reproducibility, has a strong relief,
A printing plate material having good aqueous resin coating resistance can be provided.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-278053 (JP, A) JP-A-2-125262 (JP, A) JP-A-2-125261 (JP, A) JP-A 54-1982 130680 (JP, A)

Claims (1)

(57) [Claims] 1. A photosensitive resin composition comprising (a) a soluble polymer, (b) a photopolymerizable unsaturated compound having an ethylenic double bond in a molecule, and (c) a photopolymerization initiator as essential components. In the photosensitive resin printing plate to be used, the soluble polymer is mainly composed of a water-soluble polyamide and an alcohol-soluble polyamide, and the ratio of the soluble polymer in the photosensitive resin composition is 20% by weight or more and 70% by weight or less. And
When the proportion of the water-soluble polyamide in the soluble polymer is 30
A photosensitive resin printing plate, wherein the content of the photopolymerizable unsaturated compound in the photosensitive resin composition is 30% by weight or more and 70% by weight or less.