JPS58100126A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain a material for a printing plate developable with water and having high image reproducibility by using partially saponified polyvinyl acetate contg. introduced (meth)acryloyl groups and multifunctional (meth)acrylate. CONSTITUTION:Polyvinyl acetate having >=60mol% saponification degree is reacted with a compound contg. a (meth)acryloyl group and an epoxy group in the same molecule such as glycidyl acrylate or glycidyl alpha-chloroacrylate. To the resulting saponified polyvinyl acetate (A) contg. introduced (meth)acryloyl groups are added photopolymerizable multifunctional (meth)acrylate (B) having <=2,000mol.wt. and contg. a hydroxyl group and >=2 (meth)acryloyl groups in the same molecule and a satd. compound (C) having <=1,000mol.wt. and >=150 deg.C b.p., contg. hydroxyl groups, and improving the compatibility of the component A with the component B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel water-developable photosensitive resin composition, and in particular, a photosensitive resin composition based on saponified polyvinyl acetate that provides a printing plate material with extremely high image reproducibility. This invention relates to a resin composition.

There are several known examples of systems using fully saponified or partially saponified polyvinyl acetate↓ as the main resin, which are photosensitive resin compositions that can be developed with neutral water by utilizing a photoinsolubilization reaction caused by photopolymerization. be.

Known examples can be roughly divided into two types.

The first system imparts photosensitivity by blending completely saponified or partially saponified polyvinyl acetate with polymerizable monomers (Japanese Patent Publication No. 46-39401, Japanese Patent Publication No. 48-87903, 1976-27602). Second
The system imparts photopolymerizability by reacting the hydroxyl group of completely saponified or partially saponified polyvinyl acetate with a compound having an unsaturated group (Japanese Patent Publication No. 4B-6).
962, Special Publication No. 49-5923. Japanese Patent Publication No. 48-5528
2. Japanese Patent Publication No. 48-65292. Japanese Patent Publication No. 48-66151
．． Japanese Patent Publication No. 50-30602. Unexamined Japanese Patent Publication No. 5 [1-45 [1]
87, Japanese Patent Publication No. 54-13890).

In the case of compounds containing photopolymerizable monomers as shown in the known examples of the first system, the saponified polyvinyl acetate polymer is physically included in the crosslinked structure formed by polymerization of the photopolymerizable monomers. It is not incorporated into the cross-linked structure through chemical bonding.For this reason, the water resistance of the relief-forming part cured by photopolymerization is insufficient.Therefore, the reproducibility of fine images is is insufficient, making it difficult to put it to practical use in high-grade printing plates that require reproduction of 3-inch halftone dots or 40 μm fine lines.

Regarding the second system of introducing ↑ saturated groups into saponified polyvinyl acetate, see 9. Special Publication Showa 48-6962゜Special Publication Showa 4
8-66151. JP-A-50-45087 introduces unsaturated groups by reacting maleic acid or its derivatives with the hydroxyl groups of saponified polyvinyl acetate.
JP-A-48-55282 is cinnamic acid ester, JP-A-48-55282
8-65292 reacts unsaturated lactone in the same way.

However, just by introducing the saponified polyvinyl acetate unsaturated paper base in this way, it is necessary to introduce a very large number of unsaturated groups in order to impart image reproducibility to the paper as a second printing material. However, in this case, the amount of hydroxyl groups that impart water solubility to the saponified polyvinyl acetate also decreases significantly, resulting in a rapid decrease in water developability. Therefore, it is extremely difficult to achieve both good image reproducibility and water developability.

In order to improve these shortcomings, the Special Publication Act of 1973-1985 was introduced.
In 23, unsaturated groups were introduced into partially saponified polyvinyl acetate by reacting N-methylolacrylamide.

It is proposed to blend this polymer with photopolymerizable acrylate. Also, in JP-A-54-138090,
An unsaturated group is introduced into partially saponified polyvinyl acetate by reacting an unsaturated aldehyde such as acrolein,
It has been proposed to add a photopolymerizable acrylate or methacrylate to this. However, in these cases, since the unsaturated group introduced into the partially saponified polyvinyl acetate is not a (meth)acryloyl group, copolymerizability with the (meth)acryloyl group of the photopolymerizable monomer is extremely poor. Therefore, the probability that the partially saponified polyvinyl acetate polymer itself will be incorporated through chemical bonds into the crosslinked structure formed by polymerization of the photopolymerizable monomer is extremely low. Therefore, even if a photopolymerizable monomer is added, the expected improvement in image reproducibility cannot be achieved.

The present inventor has extremely high image reproducibility.

Moreover, as a result of intensive studies on completely saponified or partially saponified polyvinyl acetate photosensitive resin compositions that can be developed with neutral water, the present invention as described below has been achieved.

That is, the present invention relates to a photosensitive resin composition characterized by comprising 9-order A, B, and C components.

A. 0.1 to 40 parts by weight of a compound having an epoxy group and a (meth)acryloyl group in the same molecule, based on 100 parts by weight of partially saponified or completely saponified polyvinyl acetate with a degree of saponification of 60 molar or higher. Partially saponified or completely saponified water into which an acryloyl group has been introduced (containing ÷→hemeta) obtained by the reaction IJ l'i + vinyl acid
100 parts t-8 parts B0 A photopolymerizable polyfunctional (meth)acrylate with a molecular weight of 2000 or less and having hydroxyl J+ (and two or more (meth)acryloyl groups in the same molecule) 10 to 500""ii Iiii, 1 to 100 parts by weight of a saturated compound having a hydroxyl group in the molecule having a molecular weight of 100 e or less and a boiling point of 150° or more Each component of the present invention will be described in detail.

As the saponified polyvinyl acetate used as a raw material for component A, one having a saponification degree of 60 mol or more is used. If the saponification degree is less than 60 molar, water solubility is lost, so the lower limit of the saponification degree is 60 molar. In addition, the degree of saponification is 1
00 parts by weight of completely saponified polyvinyl acetate is also known to have poor water solubility, but in the present invention, as described later, (
An epoxy compound having a meth)acryloyl group also reacts with active hydrogen in the hydroxyl group of saponified polyvinyl acetate.
It is possible to obtain good water solubility, similar to that of partially saponified products, by selecting reaction conditions for this purpose. Therefore, the saponified polyvinyl acetate that can be used as a raw material for component A may have a saponification degree of 60 molti or more. Any molecular weight can be used, but a polymerization degree of 200 to 2000 is preferred from the viewpoint of compatibility with component B.

Examples of compounds having a (meth)acryloyl group and an epoxy group in the same molecule to be reacted with this saponified polyvinyl acetate include the following.

glycidyl acrylate, glycidyl methacrylate,
a-glycidyl chloroacrylate, etc.

It can also be obtained by reacting a known epoxy resin (diepoxide) with an unsaturated compound having active hydrogen, such as an unsaturated carbodiic acid, an unsaturated amine, or an unsaturated oroalcohol. That is, a carboxylic acid having an epoxy group and a (meth)acryloyl group in the same molecule obtained by reacting one epoxy group of an epoxy resin with a compound such as a carboxylic acid having a (meth)acryloyl group. The present invention also includes a compound having an epoxy group and a (meth)acryloyl group in the same molecule, which is obtained by reacting the following compounds. It is of course possible to use not only tp but also two or more of these compounds in combination to obtain component A.

In this compound having an epoxy group and a (meth)acryloyl group in the same molecule, the carboxylic acid terminal and some hydroxyl groups of saponified polyvinyl acetate react with the epoxy group. As a result, a (buta)acryloyl group is introduced into the saponified polyvinyl acetate.

It is already known that a carboxyl group exists at the end of partially saponified polyvinyl acetate (for example, in ``Polymer Chemistry'').
Volume 14, No. 143, pp. 11-16.

It was also confirmed by conductivity titration and polarography that the epoxy group of the compound easily reacts with the carboxyl group.

This reaction can be roughly expressed as follows.

OHR (saponified polyvinyl acetate into which a (meth)acryloyl group has been introduced) (where R is H) or cHI) This reaction involves the reaction of saponified polyvinyl acetate in water alone or in a mixed solvent of alcohol/water. After completely dissolving in (meta)
Adding an epoxy compound with an acryloyl group, 60~
The process proceeds easily at a temperature of 80°C in a short time of one hour or less without the addition of a catalyst. Through this reaction, a (meth)acryloyl group is introduced at the end of the saponified polyvinyl acetate.

In addition to this reaction, a reaction between the hydroxyl group of the saponified polyvinyl acetate and the epoxy group also occurs, and a pendant (meth)acryloyl group is introduced. This reaction is used to quantify the hydroxyl value,
As estimated from infrared absorption spectra, etc., the reaction is extremely slow in the absence of catalysts.To promote these reactions, suitable ebogi/ring-opening catalysts1 such as triethylbenzylammonium chloride, aluminum chloride, triphenyl Phosphine, phosphoric acid, etc. may also be added. However, the reaction between the carboxyl groups and epoxy groups of the saponified poly-61-acid vinyl wood ends can easily proceed in a short time by applying a temperature of 60°C or higher, so the addition of a catalyst is often unnecessary.Hydroxyl groups and epoxy groups The reaction with the epoxy group is much slower than this, so it is necessary to add a catalyst.However, if too much catalyst is added, an addition reaction of the epoxy compound will often occur and gelation will occur, so the reaction conditions should be adjusted accordingly. It is necessary to choose f1 carefully.

The compound having a (meth)acryloyl group and an epoxy group is used based on 100 parts by weight of completely saponified or partially saponified polyvinyl acetate as a raw material.

It is necessary that the amount is in the range of 0.1 to 40 parts by weight.

If it is less than 0.1 part by weight, the amount of (meth)acryloyl group introduced is so small that no effect on improving image reproducibility is observed. On the other hand, if the amount exceeds 4 parts by weight, depending on the reaction conditions, the hydroxyl groups may react excessively and the water solubility of the saponified polyvinyl acetate may be lost, or the unreacted epoxy groups and (meth) Since a large amount of the compound having an acryloyl group remains in the composition, the photosensitive properties are often adversely affected.

For these reasons, it is necessary that the amount of the compound having an epoxy group and a (meth)acryloyl group used is in the range of 0.1 to 40 parts by weight per 10 parts by weight of saponified polyvinyl acetate. More preferably, 1 to 20 parts by weight provides the best image reproducibility improvement effect.

Photopolymerizable polyfunctional (meth)acrylates having a molecular weight of 2000 or less and having a hydroxyl group and two or more (meth)acryloyl groups in the same molecule include the following: There is no limitation to this as long as it satisfies one condition. Glycerol di(meth)acrylate, trimethyl□ropropane di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, torino f-role di(meth)acrylate, deto'
Epoxy groups of polyvalent glycidyl ethers such as nomethylolethane di(meth)acrylate, detone methylolethane tri(meth)acrylate, and ethylene glycol diglyndyl ether, and (meth)acryloyl groups such as (meth)acrylic acid. Polyfunctional (meth)acrylates that have a hydroxyl group produced by the reaction of the active hydrogen of a carboxylic acid with a plurality of (meth)acryloyl groups, as well as polyvalent glycidyl ethers and 2-hydroquinethyl Compounds having a hydroxyl group and multiple (meth)acryloyl groups produced by the addition reaction of a compound having a (meth)acryloyl group and a hydroxyl group such as (meth)acrylate, and conversely a (meth)acryloyl group such as glycidyl (meth)acrylate. having a hydroxyl group and multiple (meth)acryloyl groups produced by the reaction of a compound having an epoxy group with a compound having an active hydrogen such as a saturated or unsaturated carboxylic acid, alcohol, IIIT or secondary amine These include polyfunctional (meth)acrylates.

These photopolymerizable polyfunctional (meth)acrylates as component B have a hydroxyl group in the molecule, so A, which is a water-soluble polymer,
It shows relatively good compatibility with the component saponified polyvinyl acetate into which (meth)acryloyl groups have been introduced. Therefore, curing by photopolymerization proceeds uniformly and efficiently. Also,(')
1) Since it has an acryloyl group, it has extremely good copolymerizability with the (meth)acryloyl group introduced into component A. Therefore, the saponified polyvinyl acetate is efficiently and firmly incorporated through chemical bonds into the extremely dense crosslinked structure produced as a result of photopolymerization of the polyfunctional (meth)acrylate of disposal B. Therefore, in cases where saponified polyvinyl acetate is only physically included in the crosslinked structure, or when (
Compared to cases where unsaturated groups other than meth)acryloyl groups are introduced into saponified polyvinyl acetate, curing progresses more rapidly in areas irradiated with actinic rays, resulting in a plate material with high sensitivity and extremely good image reproducibility. is obtained. Further, since the water resistance of the hardened portion is good, a part of the hardened portion is prevented from being eluted into water during immersion in neutral water.

Since component B has hydroxyl groups in nine molecules, it exhibits relatively good compatibility with component A, but when the molecular weight exceeds 20,110, the compatibility decreases rapidly. The molecular weight of the -C18 component is preferably 2000 or less.

The amount of component B used is 100 parts by weight of component A by χj.
If the amount is less than 1 part by weight, the crosslinked structure produced by photopolymerization will not be sufficiently dense, making it impossible to obtain good image reproducibility. In addition, if it is above 600 cm, the crosslinked structure due to photopolymerization will become overcrowded and the photocured part will become brittle.
Problems such as cracks may occur. Therefore, B
The amount of component used is 10 to 60 parts by weight per 100 parts by weight of component A.
It is necessary that the weight is in the range of 0 weight 1 part, and 20 to 15 parts.
0 parts by weight is more preferred. 2 or more types as B component, 1-
It is also possible to use these together.

Further, photopolymerizable components other than component B may be included to the extent that the objects of the present invention are not impaired or to the extent that they are promoted. Examples of such photopolymerizable components include (methane acrylamide and derivatives thereof).

When the molecular weight of component C is 1000 or less, the boiling point isO.

As a saturated compound having a hydroxyl group in the above 6 molecules, 0
Examples include: n-hexyl alcohol, hegetyl alcohol, isohexyl alcohol, n-
'-octyl alcohol, iaoctyl alcohol, nonyl alcohol, n-acyl alcohol, benzyl alcohol, cyclohexanol, butyl cellosolve, phenyl cellosolve.

Benzyl cellosolve, 'hexyl cellosolve, 2-methoxyethoxyethanol, ethylene glycol, ethylene glycol monoacetate, diethylene glycol,
Methyl calpitol, ethyl calpitol, butyl calbi) -A/, diethylene glycol monoacetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol.

Propylene glycol, diethylene glycol.

Triglopylene glycol or polyethylene glycol with a molecular weight of 1000 or less.

Polypropylene glycol with a molecular weight of 1000 or less, 1.4-butanediol, 1.5-bentanediol, glycerin, glycerin monoacetate, glycerin diacetate, glycerin heptanobutyrate, glycerin cyphthylate, diglycerin, -trimethylolmethane, trimethylolethane, trimethylolpropane, hexanetriol, tetramethylolmethane, tetramethyl 1J-ruethane, and the like. It is also possible to use two or more types of C components together.

The zero-order component plays a role in improving the compatibility between the A component and the B component. Since component B has a hydroxyl group, it exhibits relatively good compatibility with (meth)acryloyl group-introduced saponified component 1) and vinyl acetate. If fc is removed or rapidly cooled, part of the B component often seeps out onto the plate surface, or the A component and B component phase separate within one plate material, resulting in cloudiness. Furthermore, if the zero plate material is stored at high temperatures for a long period of time, a phenomenon may be observed in which part of the B component seeps out onto the plate surface. However, when component C is added, component C becomes A due to the action of its hydroxyl group.
Since both the component and the B component have a certain degree of compatibility, these problems are solved by helping the A component and the B component to be compatible with each other. Furthermore, by adding the C component, moldability during plate material production is also improved. Furthermore, octyl alcohol and the like can be expected to have the effect of eliminating air bubbles generated when a saponified polyvinyl acetate plate material is developed with water.

Generally, when a low molecular weight saturated compound such as component C is added, image reproducibility is usually sharply reduced. However, in the present invention, component B is a polyfunctional (meth)acrylate, so the crosslinked structure formed by photopolymerization of this is extremely dense. Moreover,
Since component A has introduced a (meth)acryloyl group, saponified polyvinyl acetate itself is firmly incorporated into this crosslinked structure through chemical bonds. Therefore, it has the characteristic that image reproduction f1 does not deteriorate even if it contains a considerably large amount of saturated low-molecular-weight compound. Furthermore, when a large amount of a saturated low-molecular compound is contained, the flexibility of the exposure plate becomes good, the problem of cracking in cold weather can be solved, and the transferability of the ink is also improved. Depending on the composition, it is also possible to use shore A (f degree 60 or less) plates, such as those used in flexographic printing.

It is safe that the molecular weight of the C component is 1000 or less; if it is more than that, the compatibility with the A component and the B component will be poor. Also, regarding the boiling point.

If the temperature is below 150°C, it will be volatilized and removed from the plate material during the drying process during plate molding, so it will not be able to perform its original function of improving the compatibility of components A and C. Furthermore, if it remains in the plate after molding, it evaporates over time, causing changes in plate hardness over time. Therefore, it is necessary that the boiling point is 150°C or higher.

If the amount of component C used is less than 1 part by weight per 100 parts by weight of component A, it will not be able to play a role in promoting compatibility between components A and B. On the other hand, if 100 parts by weight or more is added,
The water resistance of the photo-cured portion is significantly reduced. From now on, C
The amount of the component used is 1 to 1 per 100 parts by weight of component A.
00 parts by weight, preferably 5 to 70 parts by weight.

A photosensitizer can be used to quickly carry out the photopolymerization reaction of the composition of the present invention. As a photosensitizer,
All conventionally known compounds can be used. Examples include benzoin alkyl ethers, benzophenones, anthracite benzyls, acetophenones, and diacetyls. These photosensitizers can be used in an amount of 0.01 to 10% by weight based on the total composition.

Furthermore, all known thermal polymerization inhibitors can be used to increase the heat resistance stability of the composition of the present invention.

Preferred main polymerization inhibitors include phenols.

Examples include hydroquinones and catechols.

It can be used in an amount of 0.01 to 5% by weight based on the total amount of the composition. Furthermore, it is also possible to add dyes, pigments, surfactants, antifoaming agents, etc.1, and the various components constituting the photosensitive resin composition of the present invention can be mixed by conventionally known methods. You can do good luck. The photosensitive resin K (acid) of the present invention thus obtained can be used in printing plate materials such as letterpress materials, intaglio printing materials, and printing plates.

It can be applied to photoresist etc.

Among these, it is most suitable for use as a plate material for letterpress printing as it exhibits its characteristics the most.

A photosensitive resin letterpress material using the photosensitive resin composition of the present invention is produced, for example, by the following method. That is, a photosensitive layer is formed from a solution of a photosensitive resin composition. The photosensitive layer can be formed by distilling off the solvent in the solution, drying it, granulating it, applying heat and pressure onto a support using a press, etc. to form the photosensitive layer. or.

It is also possible to form a photosensitive layer by forming the photosensitive layer into a sheet using a dry film forming method and then fastening this sheet onto a support. Alternatively, the photosensitive layer can also be obtained by dry film forming directly on the support. Furthermore, it is of course possible to provide an adhesive layer, a single layer of primer, etc. between the support and the photosensitive layer. Iron as a support.

Metal plates such as stainless steel, aluminum, and copper, and synthetic resin sheets such as polyethylene terephthalate.

A synthetic comb sheet such as styrene-butadiene rubber is used, and the photosensitive layer is preferably formed to a thickness of 0.1 to IQ mm.

In order to form a relief image for printing using the photosensitive resin composition of the present invention, a negative film having a transparent image area is closely adhered to the photosensitive layer prepared as described above.
The photosensitive composition is cured by irradiation with ultraviolet light having a wavelength of 00 to 4QQmμ. Next, a relief is formed on the support by dissolving a portion corresponding to the valve surface line segment using, for example, a spray type developing device or a brush type developing device using water.

A feature of the photosensitive composition of the present invention is that the polyfunctional (meth)acrylate of the component B, which is relatively difficult to completely miscible with the saponified polyvinyl acetate of the component A, is saturated with a hydroxyl group as the component C. By allowing the compounds to coexist, it is possible to make them completely and uniformly compatible. By completely dissolving component A and component B, photopolymerization of the polyfunctional (meth)acrylate of component B proceeds uniformly and easily in the relief forming area. Furthermore, the light resistance of the relief area is extremely good because the saponified polyvinyl acetate polymer of component A is uniformly incorporated into the dense crosslinked structure generated by photopolymerization of the polyfunctional (meth)acrylate of component B. . however.

In general, when a low molecular weight saturated compound such as C component coexists, the water resistance of the relief area often decreases and good image reproducibility cannot be obtained6.To solve this problem, In the composition of the present invention.

Because the (meth)acryloyl group is introduced into the saponified polyvinyl acetate polymer itself of the A component, the A component also efficiently participates in the crosslinking reaction by photopolymerization, and the saponified polyvinyl acetate polymer itself has a high density. It is firmly incorporated into the highly cross-linked structure through chemical bonds. Therefore, the reduction in water resistance of the relief portion due to the coexistence of the C component is minimized, and a high degree of image reproducibility can be maintained. Also, for the C component, Δ
In addition to the role of helping the compatibility of component and B component, after photocuring,
The ink transfer property has been improved by adding flexibility to the relief part and lowering the hardness of the printing plate.

It can also be expected to work to prevent cracks from occurring during printing. Also, in the process of forming a zero plate material.

Adding component C often improves moldability. As described above, the composition of the present invention has a high degree of image reproducibility that has not been previously obtained due to the coexistence of component A, component B, and component C, and has flexibility and good ink transferability. It provides a printing plate material that can be developed with neutral water.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1. Comparative Example 1 1 mole of ethylene glycol diglycidyl ether, 2 moles of methacrylic acid, 1% by weight of triethylbenclammonium chloride, 0% of hydroquinone monomethyl ether
1% by weight was placed in a 6-volume flask and stirred for 8 hours at 80° C. under nitrogen gas flow for reaction. As a result of examining the infrared absorption spectrum of the obtained reaction product, it was found that there were two hydroxyl groups as shown below.

It was confirmed that a methacrylate monomer having two methacryloyl groups was produced.

OHuH A partially saponified polyvinyl acetate having a degree of saponification of about 78 mol/1 and a degree of polymerization of 500 was selected. 92 parts by weight of this partially saponified polyvinyl acetate were mixed with 60 parts by weight of ethanol and 60 parts by weight of water.
The mixture was dissolved by heating at 80° C. for 1 hour in a mixed solvent containing parts by weight. Then, 8 parts by weight of glycidyl methacrylate was added, and 8 parts by weight of glycidyl methacrylate were added.
The reaction was carried out at 0°C for 1 hour. Poly6/poly6 by potentiometric dropping method
1: As a result of examining the end of the vinyl acid, it was found that the carboxyl group end had completely disappeared, and a methacryloyl group was introduced at the end by reaction with glycidyl methacrylate. Changes in hydroxyl groups were also investigated using hydroxyl value and infrared absorption spectra, but it was found that most of the changes were made and no methacryloyl groups were introduced into the pendants.

Into the ethanol/water mixed solvent solution of the partially saponified polyvinyl acetate having methacryloyl groups at the terminals thus obtained, the previously obtained photopolymerizable methacrylate having two hydroxyl groups and two methacryloyl groups was added. 87 parts by weight and 10 parts by weight of diethylene glycol per 100 parts by weight of partially saponified polyvinyl acetate into which groups have been introduced.

6 parts by weight of benzoin methyl ether as a photosensitizer;
0.1 part by weight of t-butylcatechol was added as a thermal polymerization inhibitor, and the mixture was stirred at 80°C for 1 hour.

For comparison, a stock solution was similarly prepared in which the amount of the same photopolymerizable methacrylate was increased to 97 parts by weight, diethylene glycol was not added, and the other components were the same.

The obtained stock solution was cast onto a 200 μm thick polyester film coated with a polyester adhesive in advance so that the thickness after drying was 500 μm. This is 70℃
The solvent was completely removed after 2 hours. At this time, with the stock solution to which diethylene glycol was not added, a phenomenon in which the monomer seeped onto the surface of the dry sheet was observed, but with the stock solution to which diethylene glycol was added, there was no such problem, and a good dry sheet was obtained. Ta.

A solvent of water/ethanol-5o15o (weight ratio) was applied onto the surface of the diethylene glycol-added composition thus obtained, covered with a 100μ polyester film, and kept in a dark place for 1011 days. .

The cover film of this plate material was removed, and a grayscale negative film for sensitivity measurement (5 touffer
Manufactured by 215 teps 5 intensity Gu
ide) and negative film for image reproducibility evaluation (15
0 line 3%, 5%, IQ% halftone dot, diameter 150μ and 2
50μ independent points (with widths of 40μ and 60μ thin line portions) were vacuum-adhered and exposed for 1 minute with a high-pressure mercury lamp. : After the exposure was completed, development was carried out using a 197 type washing machine (liquid temperature: 60°C) containing neutral water. The non-image area was completely eluted into water after a development time of 1 minute, and a relief image could be obtained.

As a result of evaluating the obtained relief, it was found that the gray scale part remained up to 16 steps, indicating high sensitivity. It was confirmed that even the smallest details such as 3-chip halftone dots, 150μ independent dots, and 40μ thin lines were completely reproduced in the image area. The hardness of the printing plate was Shore D60.

When a printing test was conducted using the plate material thus obtained, a sharp printed product was obtained without any thick lines.

Example 2. Comparative Example 2 1 mole of propylene glycol diglycidyl ether, 2 moles of acrylic acid, 2% by weight of triethylbenjaammonium chloride, 0% of hydroquinone monomethyl ether
．． 1 part by weight was placed in a 6-tube flask and reacted at 80°C for 6 hours. From the infrared absorption spectrum of the resulting reaction product, it was found that a photopolymerizable acrylate monomer having 1 or 2 hydroxyl groups and 1 or 2 acryloyl groups as shown below was produced.

OHOH A saponified polyvinyl acetate having a degree of saponification of 71 molti and a degree of polymerization of 600 was selected. 96 parts by weight of this partially saponified polyvinyl acetate was completely dissolved in a mixed solvent of 60 parts by weight of ethanol and 40 parts by weight of water at 80'C.1. Next, 4 parts by weight of glycidyl methacrylate was added and heated at 80°C for 60 minutes.
Allowed to react for minutes. As a result of examining the reactant, it was confirmed that glycidyl methacrylate was added to the carboxyl terminal and a methacryloyl group was introduced.

In this solution, 57 parts by weight of the previously obtained photopolymerizable acrylate having two hydroxyl groups and two AcIJ Cl groups, 40 parts by weight of glycerin, and 100 parts by weight of partially saponified polyvinyl acetate into which methacryloyl was introduced, 8 by adding 6 parts by weight of dimethylbenzyl ketal as a photosensitizer.
The mixture was stirred and mixed at 0°C for 1 hour.

The stock solution obtained in this way was cast onto a 150μ thick polyester film coated with vinyl acetate adhesive in advance to a thickness of 850μ, and then placed in an open oven at 60°C for 5 hours to remove the solvent. Completely removed. This substrate was exposed to light for 2 minutes using a sheetra high-pressure mercury lamp for photocuring. Next, the same stock solution was cast onto this photocurable sheet to a thickness of 700 μm, and the sheet was placed in an oven at 60°0 for 5 hours to dry. In this way, a plate material having a laminated structure with a photocurable layer as the lower layer and having a total thickness of 1700 μm was obtained.

The same negative film as in Example 1 was vacuum-adhered to this plate material, and exposed to a chemical lamp for 8 minutes. Next, development was carried out using a brush-type washing machine containing neutral water at a temperature of 35°C.
A relief statue was obtained.

When the obtained relief was evaluated, it was found that 6-chi halftone dots,
It was found that both the 150μ independent point and the 40μ thin line were reproduced without any problems. The hardness of the printing plate is Shore A60.
It was found that the material had been made flexible to the point where it could be used as a plate material for flexographic printing.

For comparison, a plate material was obtained in exactly the same manner except that only the part in which a -C methacryloyl group was introduced by reacting glycidyl methacrylate with 9-partly saponified polyacetate pyrryl was omitted.

When this plate material was similarly evaluated, less than 10% of the halftone dots were reproduced, and the top of independent point 1 was rounded.

It was confirmed that significant distortion occurred in the 40 inch thin wire.

Example 3 70 parts by weight of completely saponified polyvinyl acetate having a polymerization degree of 100° was completely dissolved at 80° C. in a mixed solvent of 100 parts by weight of water and 2 Oij parts of ethanol. Next, 501 parts of glycidyl methacrylate and 0.5 IC, fl: part of tri'ethylbenzylammonium chloride were added,
The reaction was carried out at 80°C for 2 hours. As a result of examining the reactant, it was found that glycidyl methacrylate was completely added to the carboxyl terminal, and glycidyl methacrylate was also added to about 6 moles of the hydroxyl group.

After introducing the methacryloyl group in this way, into a saponified polyvinyl acetate solution, for 100 parts by weight of this polymer,
Glycerol dimethacrylate 8 as a photopolymerizable monomer
0 parts by weight, 10 parts by weight of ethylene glycol, and 8 parts by weight of octyl alcohol.

2 parts by weight of dimethylbenzyl ketal as a photosensitizer and 0.1 part by weight of hydroquinone as a heat stabilizer.

was added and stirred and mixed at 80°0 for 1 hour.

The stock solution obtained in this way was placed on a 250μ thick iron plate coated with epoxy adhesive to a thickness of 700μ after drying.
It spread to become. This was placed in an open oven at 60°C for 4 hours to completely remove the solvent.

is.

Using the same negative film as in Example 1, the plate material thus obtained was exposed to light for 2 minutes using a high-pressure mercury lamp, and developed using a spray washing machine containing neutral water (liquid temperature: 35'C). A relief image was obtained. Due to the effect of octyl alcohol added to the printing plate, very little bubbles were generated during spray development.

As a result of evaluating the relief, Brace N'ru is 1
It was found that up to 6 steps remained, indicating high sensitivity. The lines are 5% halftone dots, 150μ independent 7 white.

It was confirmed that a 40μ fine line was reproduced and that the image reproducibility was extremely good.

Despite the high hardness of the printing plate Noyoa D70, it was relatively flexible, and it was confirmed that no cracks were generated during printing.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Claims] (1) A photosensitive resin composition comprising the following components A, B, and C. A. 0.1 to 40 parts by weight of a compound having an epoxy group and a (meth)acryloyl group in the same molecule per 100 parts by weight of partially saponified or completely saponified polyvinyl acetate with a degree of saponification of 60 molar or more. 100 parts by weight of partially saponified or fully saponified polyvinyl acetate into which meth Y acryloyl groups have been introduced 10 to 600 parts by weight of a photopolymerizable polyfunctional (meth)acrylate having C8 1 to 100 parts by weight of a saturated compound having a hydroxyl group in the molecule with a molecular weight of 1000 or less and a boiling point of 150°C or higher