JPS6163837A - Photosensitve resin composition - Google Patents

Abstract

PURPOSE:To obtain a flexographic printing plate material having excellent ink transferrability, solvent resistance, wear resistance and durability by using a compsn. consisting of specific polyether ester amide and photopolymerizable vinyl monomer for a photosensitive layer. CONSTITUTION:The photosensitive compsn. consisting of 100 pts.wt. the polyether ester amide formed by polymerizing (a) the diamine expressed by the formula, (b) aliphat. or alicyclic dicarboxylic acid of 6-16C of the equal mole to the mole of said diamine (the component (a) and the component (b) may be in the form of a mixture or salt), (c) polyalkyleneoxide glycol having 300-3,000 number average mol.wt. and (d) dicarboxylic acid of 4-20C in such a manner that the polyamide unit derived from the component (a) and the component (b) is incorporated therein at 2-95wt% and that the polyether ester unit derived from the component (c) and the component (d) is incorporated therein at 98-5wt% and 5-300pts.wt. the photopolymerizable vinyl monomer having an ethylenic unsatd. bond at the terminal and >=150 deg.C b.p. is used. A relief image for printing having excellent performance is obtd. from the photosensitive layer formed on a base by using the soln. of such compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a photosensitive resin composition suitable as a material for producing printing plates, particularly flexo printing plates. More specifically, flexibility can be obtained by blending a photopolymerizable monomer with a special polyether ester amide.

The present invention relates to a photosensitive resin plate material having excellent rubber elasticity, water resistance, solvent resistance, and image reproducibility.

(Prior art) Conventionally, as a plate material for flexographic printing, an original plate is manufactured by etching a metal plate, a master mold is created by hot-pressing a thermosetting resin (for example, phenolic resin), and then a master mold is created by hot-pressing a thermosetting resin (for example, phenolic resin). It has been manufactured by pouring rubber into a mold, applying pressure, and vulcanizing it.

However, this method requires skill for one working day, is costly and time consuming, and has drawbacks such as poor image reproducibility of the obtained rubber plate itself.

In order to solve these drawbacks, in recent years, a method of directly producing flexible printing plates using a photosensitive distoma composition has been proposed. This plate material is made by attaching a negative or positive original film with one transparent part to a photosensitive layer made of an elastomer and a photopolymerizable vinyl monomer, and then irradiating actinic light through this film to correspond to the transparent part of the original film. A relief is formed by photopolymerizing the photosensitive resin layer and then dissolving the unpolymerized portion into a suitable solvent.

As described above, there are several known examples of photosensitive flexographic printing plates that utilize photopolymerization reactions in relation to the elastomer used. For example, U.S. Pat. No. 2,948,611 and U.S. Pat. No. 3,024,180 propose photosensitive resins for flexo plates in which a photopolymerizable monomer having an ethylenically terminal unsaturated bond is blended with chloroprene rubber or polyurethane rubber. Also I U.S. Patent No. 5674
No. 486 proposes a system using styrene-butadiene rubber or styrene-inobutylene rubber as an elastomer, and French Patent No. 2105825 proposes a system using acrylonitrile-butadiene rubber.
Japanese Patent Publication No. 52-28044 proposes a system containing 1,2-polybutadiene as the main resin.

[Problem that the invention seeks to solve]

A photosensitive flexo plate material using a photosensitive layer obtained by blending a photopolymerizable upper layer with Elasto i is easier to work with and has better image reproducibility than a rubber plate.

However, due to the poor rubber elasticity of printing plates, ink transferability is insufficient, and vulcanized rubber plates are also resistant to solvents.

There are problems such as poor wear resistance and durability. As a result of intensive study on solving these problems, the present inventors found that
We have arrived at the present invention.

[Means for solving problems]

The present invention provides a photosensitive resin composition that solves the drawbacks of conventional photosensitive flexographic printing plates. In particular, one aspect of the present invention is ink transferability and solvent resistance.

The present invention provides a photosensitive resin composition useful for the photosensitive layer of a flexographic printing plate material, which has excellent abrasion resistance and durability.

Specifically, the present invention relates to a photosensitive resin composition characterized by comprising secondary components A and B.

A, an aliphatic or alicyclic dicarboxylic acid (b) having 6 to 15 carbon atoms, which is substantially the same as the diamine (a) represented by the following formula (I) (provided that (a) (component (b) may be in the form of a mixture or a salt).

Poly(alkylene/OΦ) with a number average molecular weight of 300 to 3000
Cyto) glycol (G) and a dicarboxylic acid (d) having 4 to 20 carbon atoms are combined with 2 to 95 weight polyamide units derived from components (a) and (b) -9 (O) component and (
d) 9 polyetherester units derived from component
100 parts by weight of polyester amide polymerized to contain 8 to 5% by weight B, having an ethylenically unsaturated bond at the end and a boiling point of 150%
5 to 300 parts by weight of a photopolymerizable vinyl monomer having a temperature of 5 to 300 parts by weight.Next, each component of the present invention will be explained in more detail.

The polyether ester amide which is component A of the present invention is 1
It can be obtained by polymerizing the following components. First, R in diamine (a) represented by Formula 1 (r) is alkylene or alkylidene having 1 to 4 carbon atoms, and typically represents methylene, ingropylidene, etc. Such diamines include trans-trans and/or trans Representative examples include -cis and/or cis-cis-4,4'-diaminodicyclohexylmethane. Examples of the aliphatic or alicyclic dicarboxylic acid (b) having 6 to 15 carbon atoms include aliphatic dicargenic acids such as adipic acid-azesylaic acid, sebacic acid, and dodecadionic acid, 1,2-cyclohexane dicarboxylic acid, and dicyclohexyl. There are alicyclic dicarboxylic acids such as -4,4'-dicarboxylic acid, but azelaic acid,
Sebacic acid and dodecadionic acid are preferred.

The poly(alkylene oxide) glycol(0) having a number average molecular weight of 300 to 3,000 in component A is polyethylene glycol, poly(I,2-Oyohi 1.3-
propylene oxide) glycol.

Examples include poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, block or random copolymers of ethylene oxide and propylene oxide, and block or random copolymers of ethylene oxide and tetrahydrofuran. Poly(tetramethylene oxide) glycol having a number average molecular weight of 500 to 2,000 is preferably used from the viewpoints of water resistance, solvent resistance, flexibility, mechanical strength, elastic recovery, etc. of the polymer.

As the dicarboxylic acid (d) having 4 to 20 carbon atoms.

Terephthalic acid, isophthalic acid, phthalic acid, naphthalene
Aromatic dicarbo/acids such as 2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid/diphenoxyethanodicarboxylic acid, sodium 5-sulfoisophthalate, 1,4-cyclohexane alicyclic dicarboxylic acids such as dicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, dicyclohexyl-4,4-dicarboxylic acid, and succinic acid, adipic acid,
Sebacic acid.

Mention may be made of aliphatic dicarboxylic acids such as decanedicarboxylic acid. Although (d) can be used even if it is different from (b), it is preferable that they are the same from the physical properties of the resulting polyether ester amide.

The method for polymerizing polyether ester amide is not particularly limited, but after preparing the salts of (a) and (b), this salt and CO>+ (d) are heated at a temperature of 230 to 320°C. Melt polymerization under vacuum is particularly preferred since a high quality polymer can be obtained.

The composition of component A is 2 to 95% by weight of polyamide units derived from components (a) and (b), and 98 to 98% by weight of polyether ester units derived from inverse K(0) component and component (d). 5 weight -. That is, if the amide unit is less than 2 by weight, the mechanical strength of the resulting polymer will be extremely low, resulting in insufficient printing plate strength when applied to a printing plate material. In addition, the amide unit is 95 weight -
If it exceeds this amount, the polymer will become highly crystalline due to the influence of hydrogen bonds formed between amide units, and the compatibility with the photopolymerizable monomer of component B will decrease significantly. For the above reasons.

The amide units need to be in the range of 2 to 95% by weight, preferably 5 to 60% by weight.

Polyethers that have unsaturated groups introduced at the ends by reacting active hydrogen containing carboxyl groups, amines, hydroxyl groups, etc. present at the ends of polyether ester amide with unsaturated epoxy groups such as glycidyl (meth)acrylate. Ester amides can also be used.

Component B has an ethylenically unsaturated bond at the end.

Photopolymerizable vinyl monomers having a boiling point of 150° C. or higher include the following, but are not limited to these as long as they satisfy two conditions.

2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-chloro-2
-Hydroxypropyl (meth)acrylate, (meth)acryloyloxyethyl hydrogen phthalate, β-hydroxyethyl-/-(meth)acryloyloxyethyl phthalate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, succinoyloxy Ethyl (meth)
Monofunctional vinyl monomers with one ethylenically unsaturated bond in the molecule, such as acrylate, (meth)acrylamide, N-methylol (meth)acrylamide diacetone (meth)acrylamide, ethylene glycol di(meth)
acrylate, polyalkylene glycol di(meth)acrylate such as probile/glycol di(meth)acrylate), 1,4-butanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate.

Pentaerythritol tri(meth)acrylate.

Pentaerythritol tetra(meth)acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate, addition reaction product of polyvalent glycidyl ether and (meth)acrylic acid.

Addition reaction product of polyhydric carboxylic acid and glycidyl (meth)acrylate, addition reaction product of unsaturated carboxylic acid and glycidyl (meth)acrylate, addition reaction product of polyhydric alcohol and glycidyl (meth)acrylate.

Addition reaction product of unsaturated alcohol and glycidyl (meth)acrylate, addition reaction product of primary amine and glycidyl (meth)acrylate, methylenebis(meth)acrylamide, hexamethylenebis(meth)acrylamide, triacrylform! These include polyfunctional vinyl monomers having two or more ethylenically unsaturated bonds in the molecule, such as vinyl and divinylbenzene.

It is necessary that the boiling point of the photopolymerizable vinyl monomer as component B is 150°C or higher. 2 if the boiling point is below 150℃
When forming a plate material, most of it is scattered outside the plate material and sufficient image reproducibility is often not obtained.

Another serious problem is that image reproducibility changes over time because the particles scatter outside the plate even after one plate is formed.

The amount of component B used must be in the range of 5 to 500 parts by weight based on 100 parts by weight of the polyether ester amide of component A. If the amount used is less than 5 parts by weight, the density of the crosslinked structure produced by photopolymerization will be too low, making it impossible to obtain sufficient image reproducibility. On the other hand, if more than 500 parts by weight is used, the crosslinking density is too high and the photo-cured portion becomes extremely brittle, causing problems such as pricking during printing. From the above, it is necessary that the amount of component B used is in the range of 5 to 500 parts by weight, preferably in the range of 10 to 150 parts by weight.

It is also possible to incorporate a suitable plasticizer in order to improve the moldability and flexibility of the plate material obtained from the composition of the present invention. Any saturated compound that has a certain level of compatibility with the polyether ester amide of component A can be used as the plasticizer. Generally, when a large amount of plasticizer is used, image reproducibility often decreases rapidly because the crosslinking density of the photocured portion decreases. but.

Products in which unsaturated groups are introduced by reacting glycidyl methacrylate etc. with the terminals of polyether ester amide are 1.
There is a slight decrease in image reproducibility.

All conventionally known compounds can be used as the photosensitizer for quickly carrying out the photopolymerization reaction of the composition of the present invention. For example, penceyl/alkyl ethers, benzophenones, anthoquinone a, benzyls, acetopheno 7s.

Examples include diacetyls. These photosensitizers are
It can be used in the range of α01 to 10 weight for the entire composition.

In order to increase the thermal stability of the composition of the present invention, known thermal polymerization inhibitors can be used. Preferred thermal polymerization inhibitors include phenols, hydroquinones, catechols, and the like.

In order to improve heat resistance, it is also possible to add a phosphorus compound such as triphenylphosphine or L-ascorbic acid. Further, known dyes, pigments, antioxidants, ultraviolet absorbers, surfactants, etc. can also be added.

A printing plate material for printing using the photosensitive resin composition of the present invention thus obtained is manufactured by, for example, 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. Alternatively, it is also possible to form a sheet by a dry film forming method and adhere this sheet onto a support to form a photosensitive layer.

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. As the support, a metal plate such as iron, stainless steel, aluminum, or copper, a synthetic resin sheet such as polyethylene terephthalate, or a synthetic rubber sheet such as styrene-butadiene rubber is used, and the photosensitive layer is formed to a thickness of 0.1 to 10 mm. It is preferable to do so.

In order to form a relief image for printing using the photosensitive resin composition of the present invention, a negative or positive original 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 centered at a wavelength of ~400 mμ. Next, a relief is formed on the support by eluting the uncured portion with a brush or spray developing device using a suitable developer such as water or alcohol.

The photosensitive resin composition of the present invention is most effective when used as a plate material for flexographic printing, but it can also be used as letterpress materials, intaglio materials, planographic materials, stencil materials, and photoresists other than 7 lexo. It is also possible to do so.

〔Example〕

The present invention will be explained more specifically in the following examples.

Example 1 Salt of 4.4'-diaminodicyclohexylmethane and dodecadionic acid 16.3 parts by weight 197 parts by weight of dodecadionic acid and 68.4 parts of poly(tetramethylene oxide) glycol having a number average molecular weight of 800 were mixed with "Irganox" 1
098 (antioxidant) and 0.05 parts by weight of tetrabutyl titanate catalyst into a reaction vessel equipped with a helical rib/stirring blade.

After purging with N2 and heating and stirring at 250°C for 30 minutes to obtain a homogeneous transparent solution, the polymerization conditions were brought to 280°C and high vacuum of 1 aoHg or less in 50 minutes according to a temperature increase and pressure reduction program. When reacted under these conditions for 2 hours, a viscous, colorless and transparent molten polymer was obtained.

This polymer was discharged into water as a gut.

The polyamide hard segment of the polyether ester amide obtained as described above has a weight of 15. The relative viscosity (mar) measured in orthochlorophenol at 25°C 1α5 weight was 1.88.

100 parts by weight of the above polyether ester amide was dissolved by heating at 70°C in 300 parts by weight of trichlorethylene. Next, 2 parts by weight of glycidyl methacrylate was added and stirred for 1 hour to introduce a double bond at the end of the polymer. Next, 70 parts by weight of tetraethylene glycol diacrylate as a photopolymerizable vinyl monomer, 29 parts by weight of N-butylbenzenesulfonamide as a plasticizer, 1 part by weight of dimethylbenzyl ketal as a photosensitizer, and hydroquinone monomethyl ether as a thermal polymerization inhibitor. 01 parts by weight were added and thoroughly stirred and mixed.

The photosensitive resin solution thus obtained was placed on a polyester film substrate with a thickness of 150 μm, which had been coated with a polyester adhesive in advance, so that the total thickness after drying was 2 μm.
000μ.

This was placed in an audan at 60° C. for 10 hours to remove the solvent.

After storing the obtained plate material in a dark place for one week.

The entire surface was exposed for 20 seconds using a chemical lamp from the substrate surface side.

Next, test negative film (I33 line 5Ls
and 10-halftone dots, 300μ diameter independent points ζ thin line portions with line widths 50μ and 75μ) were vacuum-adhered and exposed to chemical lamp for 8 minutes. This exposed plate material was filled with tric chlorethylene and washed for 4 minutes using a nose brush type washing machine (liquid temperature: 25° C.). Obtained depth approximately 1000μ
When we examined the reliefs of Liao, we found that even the smallest details were sufficiently reproduced. The hardness of the printing plate is Shore A5.
The hardness was 0 degrees, which was suitable for flexographic printing.

Using this printing plate, a printing test was carried out on a polypropylene film using a flexographic printing ink containing 25 weight parts of ethyl monoacetate. As a result, no swelling of the relief caused by the ink, which is seen with ordinary photosensitive 7 lexo plate materials, was observed, and very sharp printed matter was obtained.

Example 2 4.1.8 parts by weight of a salt of 4.4'-diaminodicyclohexylmethane and sepacic acid, 14.6 parts by weight of sebacic acid and 48.2 parts by weight of poly(tetramethylene oxide) glycol having a number average molecular weight of 680. “Irganox” 1
Polyether ester amide was obtained by polymerizing in the same manner as in Example 1 together with 0.2 parts by weight of 098 (antioxidant) and 0.05 parts by weight of tetrabutyl titanate catalyst. The polyamide hard segment in this polymer is 40 wt.
and the relative viscosity (vr).

was 1°65.

100 parts by weight of this polyetheresteramide.

It was dissolved in 250 parts by weight of trichlorethylene by heating to 70°C. Next, 3 parts by weight of glycidyl tacrylate was added and reacted at 80°C for 90 minutes to form 2 parts at the end of the polymer.
Introduced double bonds. Furthermore, 50 parts by weight of hexaethylene glycol diacrylate and 5 parts by weight of tri'methylolpropane triacrylate were added as photopolymerizable vinyl monomers, 20 parts by weight of ethylene glycol monobutyl ether was added as a plasticizer, and pencey/isopropyl was added as a photosensitizer. 2 parts by weight of ether and 1 part by weight of benzoquinone α0 as a thermal polymerization inhibitor were added and thoroughly stirred and mixed.

The photosensitive resin solution obtained by K as described above.

A polyester adhesive was previously coated and cured, and then cast onto a polyester film substrate having a thickness of 100 μm so that the total thickness after drying would be 1000 μm. Next, the plate was placed in an open oven at 60''C for 4 hours to remove the solvent and obtain a green plate.

The same test negative film as in Example 1 was vacuum-adhered to the obtained plate material, and exposed for 3 minutes using an ultra-high pressure mercury lamp. Then,
When development was performed under the same conditions as in Example 1, the unexposed portion of the substrate surface was exposed in 3 minutes, so development was terminated. The hardness of the obtained printing plate was 60 degrees Shore A, which was suitable for flexographic printing. It was also confirmed that one image was reproduced down to the minute details.

Printing on a film was carried out using a flexo ink containing 50% toluene by weight, but no swelling of the relief was observed and sharp printing was possible.

Example 3 119 parts by weight of the salt of 4.4'-diaminodicyclohexylmethane and dodecadionic acid, 4 parts by weight of 1Q dodecadionic acid, and 81.2 parts by weight of poly(tetramethylene oxide) glycol having a number average molecular weight of 1800 were added to Polymerization was carried out in the same manner as in Example 1 with 2 parts by weight of NOX 01098 (antioxidant) α and 5 parts by weight of tetrabutyl titanate catalyst α0.

The polyamide hard segment in the obtained polymer was 10
The weight and relative viscosity (mar) were 1.80.

100 parts by weight of the above polyether ester amide was dissolved in 300 parts by weight of perchlorethylene under heating.

Next, 40 parts by weight of triethylene glycol diacrylate as a photopolymerizable vinyl monomer and 75 parts by weight of Pe/Zopheno as a photosensitizer were added and mixed with thorough stirring.

The photosensitive resin solution obtained as above.

On the same polyester film substrate as in Example 1.

Casting so that the total thickness after drying is 3000μ,
The plate material was obtained by placing it in an open oven at 60°0 for 24 hours to remove the solvent.

This plate material was exposed and developed in the same manner as in Example 1. The printing plate hardness was Shore A459, and the image reproducibility was good. When this printing plate was used to print on single-corrugated cardboard, printing could be performed without any particular problem.

〔Effect of the invention〕

The photosensitive resin composition of the present invention provides a photosensitive flexo plate material with excellent two-image reproducibility, ink transferability, and solvent resistance. These properties are derived from the polyether esteramide of component A. That is, since the polyether ester amide of the component A has good compatibility with the photopolymerizable vinyl monomer of the component B, excellent image reproducibility is exhibited. Further, the solvent resistance is extremely excellent because the A component is uniformly included in the crosslinked structure formed by the solvent resistance of the A component itself and the photopolymerization of the B component. Therefore, it has become possible to use flexographic inks containing large amounts of acetate and aromatic hydrocarbons, which cannot be applied to conventional photosensitive flexographic printing plates. Moreover, the excellent ink transferability is derived from the good rubber elasticity of the A component. As described above, the present invention has significantly superior performance compared to conventional photosensitive flexographic printing plates.

Claims (1)

[Scope of Claims] A photosensitive resin composition comprising the following components A and B. A, diamine (a) represented by the following formula (I) and an aliphatic or alicyclic dicarboxylic acid (b) having 6 to 15 carbon atoms in substantially the same molar amount as (a) (with the proviso that component (a) and (b)
The components may be in the form of a mixture or in the form of a salt), poly(alkylene oxide) glycol (c) having a number average molecular weight of 300 to 3000, and dicarboxylic acid having 4 to 20 carbon atoms (
d) contains 2 to 95% by weight of polyamide units derived from components (a) and (b), and 98 to 5% by weight of polyether ester units derived from components (c) and (d). 100 parts by weight of polyether ester amide polymerized so that B, 5 to 300 parts by weight of a photopolymerizable vinyl monomer having an ethylenically unsaturated bond at the end and a boiling point of 150°C or higher