JPH08297369A - Photosensitive flexographic original printing plate and photosensitive flexographic printing plate - Google Patents

Abstract

PURPOSE: To obtain an aq. solvent development type photosensitive elastomer composition high in peeling strength and excellent in dimensional stability by laminating a layer of a specific photosensitive elastomer composition and a layer of a specific adhesive composition. CONSTITUTION: After the layer 2 of the adhesive composition is formed by coating a base film 4 with the adhesive composition dissolving or swelling by the contact with an organic solvent, the photosensitive elastomer composition 1 and the adhesive composition 2 are laminated by closely adhering the base film 4 so that the photosensitive elastomer composition 1 dissolving and swelling by the contact with an aq. solvent is allowed to contact with the layer 2 of the adhesive composition. And, the photosensitive flexographic printing plate is obtained by laminating the resultant photosensitive flexographic original printing plate and a supporting plate so as to be in contact with the layer 2 of the adhesive composition of the photosensitive flexographic original printing plate. Thereby, the excellent peeling strength of the supporting plate and photosensitive elastomer composition and the improved dimensional stability are attained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive flexographic printing plate and a photosensitive flexographic printing original plate. More specifically, it relates to a photosensitive flexographic printing plate in which the support plate and the photosensitive elastomer composition are not easily peeled off and has excellent dimensional stability, and a photosensitive flexographic printing original plate for obtaining the same.

[0002]

2. Description of the Related Art Photosensitive flexographic printing plates are widely used because they can easily reproduce a rough pattern and a fine pattern.
Photosensitive flexographic printing plates for cardboard printing applications are usually
A plate thickness of 5-9 mm is required. Since it is not economical to obtain the thickness only with the photosensitive elastomer composition, a photosensitive flexographic printing plate in which the photosensitive elastomer composition and the support plate are laminated is usually used. As a method of laminating the photosensitive elastomer composition and the support, a method of laminating the photosensitive elastomer composition and the support using an adhesive is known. However, in the method of laminating using an adhesive, the volatile components in the adhesive are volatilized over a long time after the bonding, so that the adhesive layer interposed between the bonding surfaces gradually shrinks. Therefore, there is a problem that dimensions such as thickness of the photosensitive flexographic printing plate are not stable. As another method, a method has been proposed in which an organic solvent is applied to a photosensitive elastomer composition, the surface of the composition is swelled, and then the laminated composition is laminated on a support plate (Japanese Patent Laid-Open Publication No. Sho 6-62).
3-50844, etc.). However, this lamination method can be applied to an organic solvent developing type photosensitive elastomer composition that is easily swollen by an organic solvent, but is also applicable to an aqueous solvent developing type photosensitive elastomer composition that is difficult to be swollen by an organic solvent. Dimensional stability and peel strength cannot be obtained sufficiently.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a photosensitive flexographic printing plate having a strong peel strength and excellent dimensional stability of an aqueous solvent development type photosensitive elastomer composition, and a photosensitive flexographic printing original plate for obtaining the same. It is intended to provide. MEANS TO SOLVE THE PROBLEM The present inventors have conducted extensive studies in order to achieve the above object, and laminated a layer of a photosensitive elastomer composition dissolved or swollen by an aqueous solvent and a layer of an adhesive composition dissolved or swollen by an organic solvent. It was found that a photosensitive flexographic printing plate having high peel strength and excellent dimensional stability of the support plate and the photosensitive elastomer composition can be obtained by sticking the product to the support plate, and based on this finding, the present invention was completed. It came to do.

[0004]

According to the present invention, therefore, (1) a layer of a photosensitive elastomer composition which is dissolved or swelled by contact with an aqueous solvent and a layer of a photosensitive elastomer composition which is dissolved or swelled by contact with an organic solvent. There is provided a photosensitive flexographic printing original plate characterized by being laminated with a layer of the adhesive composition.

The following are provided as preferred embodiments of the photosensitive flexographic printing original plate of the present invention. (2) The photosensitive flexographic printing original plate as described in (1) above, wherein the adhesive composition contains a thermoplastic elastomer which dissolves or swells when brought into contact with an organic solvent. (3) The thermoplastic elastomer contained in the adhesive composition is polystyrene block A and polybutadiene block B.
The photosensitive flexographic printing original plate as described in (2) above, which is a block copolymer composed of or a block copolymer composed of a polystyrene block A and a polyisoprene block B.

(4) The photosensitive flexographic printing original plate as described in (2) above, wherein the thermoplastic elastomer contained in the adhesive composition is a block copolymer consisting of polystyrene block A and polybutadiene block B. (5) The photosensitive flexographic printing original plate as described in (1) to (4) above, wherein the adhesive composition contains a thermoplastic elastomer and a photopolymerizable ethylenically unsaturated monomer.

(6) The photosensitive flexographic printing original plate as described in (1) to (4) above, wherein the photosensitive elastomer composition contains a hydrophilic copolymer. (7) The photosensitive elastomer composition contains a thermoplastic elastomer, a hydrophilic copolymer, a photopolymerizable ethylenically unsaturated monomer, and a photopolymerization initiator, and the above (1) to (4) Photosensitive flexographic printing original plate. (8) The hydrophilic copolymer has a phosphoric ester group bonded to its side chain.
The photosensitive flexographic printing original plate of (7).

According to the present invention, the base film is coated with an adhesive composition which dissolves or swells when contacted with an organic solvent to form a layer of the adhesive composition, which is then contacted with an aqueous solvent. The base film is adhered to the photosensitive elastomer composition that dissolves or swells so that the layer of the adhesive composition comes into contact with the photosensitive elastomer composition, and the photosensitive elastomer composition and the adhesive composition are laminated together (1)
To (8) the method for producing a photosensitive flexographic printing original plate, and the support plate and the photosensitive flexographic printing plate so that the layer of the adhesive composition of the photosensitive flexographic printing original plate of (1) to (8) is in contact with the supporting plate. A photosensitive flexographic printing plate laminated with a printing original plate and a supporting plate, or an organic solvent is brought into contact with the layer of the adhesive composition of the photosensitive flexographic printing original plate according to (1) to (8) above, and then a supporting plate. Provided is a method for producing a photosensitive flexographic printing plate, which comprises closely contacting a layer of an adhesive composition.

The photosensitive flexographic printing original plate of the present invention comprises a layer of a photosensitive elastomer composition and a layer of an adhesive composition laminated together.

In the photosensitive flexographic printing original plate of the present invention, the adhesive composition is a composition containing a thermoplastic elastomer which dissolves or swells when contacted with an organic solvent.

Here, the organic solvent is a solvent that dissolves or swells the thermoplastic elastomer. For example, carboxylic acid alkyl esters such as ethyl acetate, methyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; aromatic hydrocarbons such as benzene, toluene and xylene;
Alicyclic hydrocarbons such as cyclopentane and cyclohexane; halogenated hydrocarbons such as trichloroethane, trichloroethylene, methylene chloride and carbon tetrachloride; and the like.

As the thermoplastic elastomer which dissolves or swells when contacted with an organic solvent, a block copolymer composed of a polystyrene block A and a polybutadiene block B, a block copolymer composed of a polystyrene block A and a polyisoprene block B, SB random copolymer containing styrene and butadiene as essential monomer units, NB random copolymer containing acrylonitrile and butadiene as essential monomer units, styrene-isoprene copolymer, methyl methacrylate-butadiene copolymer Random copolymer such as coalesce, polybutadiene, polyisoprene,
Natural rubber etc. are mentioned. The structure of the block copolymer is not limited, and examples thereof include general formulas (AB) _n and (A
_{-B) n -A, (A-} B) n -A-B, B- (A-B) n
-AB, (AB) _m- X, ((AB) _n- A) _m-
X, (B-A- (B-A) _n ) _m- X, (B-A- (B-
A) _n -B) _m -X (wherein A is a polymer block A,
B is a polymer block B, X is a residue of a coupling agent or a polyfunctional ionic polymerization initiator, n and m are integers of 1 to 10,
It is preferably an integer of 1 to 5. Examples of coupling agents include tin tetrachloride, silicon tetrachloride, epoxidized esters, polyvinyl compounds, carboxylic acid esters, and polyhalogenated hydrocarbons, and examples of polyfunctional ionic polymerization initiators include polyfunctional organic lithium compounds. To be ) Is mentioned. Among the thermoplastic elastomers, a block copolymer is preferable, and a block copolymer consisting of polystyrene block A and polybutadiene block B or a block copolymer consisting of polystyrene block A and polyisoprene block B is particularly preferable.

The layer of the adhesive composition preferably contains a photopolymerizable ethylenically unsaturated monomer in addition to the above thermoplastic elastomer. Examples of the photopolymerizable ethylenically unsaturated monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, vinyltoluene, chlorostyrene, Aromatic vinyl monomers such as vinylnaphthalene, vinylanthracene, divinylbenzene and trivinylbenzene; ethylenically unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile; methyl acrylate, ethyl acrylate, propyl acrylate, N-amyl acrylate, isoamyl acrylate, hexyl acrylate, ethylhexyl acrylate, octyl acrylate, glycidyl acrylate, methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, ethylhexyl methacrylate, octyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate,
Hydroxypropyl methacrylate, glycidyl methacrylate, ethylene glycol diacrylate, trimethylolpropane triacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, propylene glycol diacrylate, 1,6
-Hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, methoxyethylene glycol acrylate, methoxypropylene glycol methacrylate, methoxyethylene glycol methacrylate, methoxypropylene Ethylenically unsaturated carboxylic acid ester monomers such as glycol acrylate, diethyl maleate and dimethyl itaconate; ethylenically unsaturated glycidyl ethers such as allyl glycidyl ether; 1,3-butadiene, isoprene, chloroprene, 1,3-pentadiene Conjugated diene such as; ethylenically unsaturated monocarboxylic acid such as acrylic acid and methacrylic acid; maleic acid, fumaric acid, citraconic acid,
Ethylenically unsaturated polyvalent carboxylic acids such as itaconic acid; Partial esterified products of ethylenically unsaturated polyvalent carboxylic acids such as monoethyl maleate and monomethyl itaconate; Ethylene acrylate phosphate, trimethylene acrylate phosphate,
Phosphoric acid propylene acrylate, phosphoric acid tetramethylene acrylate, phosphoric acid (bis) ethylene acrylate, phosphoric acid (bis) trimethylene acrylate, phosphoric acid (bis) tetramethylene acrylate, phosphoric acid diethylene glycol acrylate, phosphoric acid triethylene glycol acrylate, phosphoric acid polyethylene glycol acrylate, phosphoric acid (bis ) Diethylene glycol acrylate, phosphoric acid (bis) triethylene glycol acrylate, phosphoric acid (bis) polyethylene glycol acrylate, and corresponding phosphoric acid ester group-containing ethylenically unsaturated monomers such as methacrylate. By incorporating the photopolymerizable ethylenically unsaturated monomer, the peel strength between the support and the photosensitive flexographic printing original plate becomes strong. The amount of the photopolymerizable ethylenically unsaturated monomer compounded in the layer of the adhesive composition is usually 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, based on 100 parts by weight of the thermoplastic elastomer. Parts by weight. If the amount is too large, the thickness of the adhesive composition layer becomes uneven, and the appearance of the photosensitive flexographic printing original plate becomes ugly. A photopolymerizable initiator may be added to the layer of the adhesive composition, if necessary. Examples of the photopolymerization initiator include α-diketones such as diacetyl and benzyl; acyloins such as benzoin and pivaloin; acyloin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether; polynuclear compounds such as anthraquinone and 1,4-naphthoquinone. Quinone; and the like.

The thickness of the layer of the adhesive composition is usually from 30 to
It is 200 μm, preferably 40 to 100 μm. 30
When it is less than μm, the peel strength is low, and when it exceeds 200 μm, the adhesive surface between the photosensitive flexographic printing original plate and the support becomes brittle, and the followability of the photosensitive flexographic printing original plate to the movement of the support is lowered.

In the photosensitive flexographic printing original plate of the present invention, the photosensitive elastomer composition layer is a layer composed of the photosensitive elastomer composition which is dissolved or swelled by contact with an aqueous solvent.

Here, the aqueous solvent means water or an aqueous solution. The solute dissolved in the aqueous solution is not particularly limited, and examples thereof include those that make the aqueous solution alkaline, such as sodium hydroxide, sodium carbonate, and ammonia; those that make the aqueous solution acidic, such as carboxylic acid, hydrogen chloride, and hydrogen sulfide. Other examples include fatty acid alkanolamides and surfactants such as sodium dodecylbenzenesulfonate.

The photosensitive elastomer composition that dissolves or swells when contacted with an aqueous solvent is not limited,
A composition containing at least a hydrophilic copolymer, preferably a composition containing a thermoplastic elastomer, a hydrophilic copolymer, a photopolymerizable ethylenically unsaturated monomer and a photopolymerization initiator.

The hydrophilic copolymer, which is a component of the photosensitive elastomer composition, has —OH, —COO in its molecular side chain.
_{H, -NH 2, -COO -,} - SO 3 H, -SO 3 -, -
PO (OH) ₂ , -PO (OH)-,> PO-, -CN
Hydrophilic groups such as -PO (OH) ₂ , -PO (O
H)-,> PO- such as phosphate groups or -CO
OH, and more preferably one having a phosphoric acid ester group bonded thereto.

The hydrophilic copolymer is usually obtained by copolymerizing an ethylenically unsaturated monomer having a hydrophilic group and a monomer copolymerizable therewith.

The ethylenically unsaturated monomer having a hydrophilic group includes ethylenically unsaturated monocarboxylic acids such as acrylic acid and methacrylic acid; ethylenically unsaturated polycarboxylic acids such as maleic acid, fumaric acid, citraconic acid and itaconic acid. Carboxylic acid;
Partial esterification products of ethylenically unsaturated polyvalent carboxylic acids such as monoethyl maleate and monomethyl itaconate; ethylenically unsaturated carboxylic acid hydroxy such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate Alkyl ester; Ethylenically unsaturated nitrile monomer such as methacrylonitrile and acrylonitrile; Phosphoric acid ethylene acrylate, phosphoric acid trimethylene acrylate, phosphoric acid propylene acrylate, phosphoric acid tetramethylene acrylate, phosphoric acid (bis) ethylene acrylate, phosphoric acid (bis) trimethylene Acrylate, Phosphoric acid (bis) tetramethylene acrylate, Diethylene glycol acrylate, Triethylene glycol acrylate, Polyethylene phosphate Ethylenically unsaturated monomers containing phosphoric acid ester groups such as glycol acrylate, phosphoric acid (bis) diethylene glycol acrylate, phosphoric acid (bis) triethylene glycol acrylate, phosphoric acid (bis) polyethylene glycol acrylate and corresponding methacrylates; sodium styrene sulfonate , 2-sulfonate fatty acid allyl sodium; t-butylaminoethyl acrylate, N, N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl acrylate, and corresponding ethylenically unsaturated aminoalkyl esters such as methacrylate. . Among these ethylenically unsaturated monomers having a hydrophilic group, a phosphoric acid ester group-containing ethylenically unsaturated monomer or an ethylenically unsaturated carboxylic acid, particularly phosphoric acid ethylene acrylate,
Propylene phosphate acrylate and their corresponding methacrylates are preferred.

The optimum range of the amount of the ethylenically unsaturated monomer having a hydrophilic group varies depending on the kind of hydrophilic group. In the case of an ethylenically unsaturated monomer having a phosphoric acid ester group, its amount is usually 3 to 50% by weight, preferably 5 to 30% by weight, based on the total monomers used for obtaining the hydrophilic copolymer. %
Is. If it is less than 3% by weight, the relief developing rate of the plate obtained by using the photosensitive elastomer composition tends to decrease. If it exceeds 50% by weight, the processability of the photosensitive elastomer composition and the resistance to water-based ink tend to decrease.

As the monomer copolymerizable with the ethylenically unsaturated monomer having a hydrophilic group, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p
Aromatic vinyl monomers such as -tert-butylstyrene, 1,3-dimethylstyrene, vinyltoluene, chlorostyrene, vinylnaphthalene, and vinylanthracene; methyl acrylate, ethyl acrylate, propyl acrylate, n-amyl acrylate. , Isoamyl acrylate, hexyl acrylate, ethylhexyl acrylate, octyl acrylate, glycidyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, ethylhexyl methacrylate Ethylenically unsaturated carboxylic acid ester monomers such as octyl methacrylate and glycidyl methacrylate; ethylenically unsaturated glycidyl ethers such as allyl glycidyl ether;
1,3-butadiene, isoprene, chloroprene, 1,
Conjugated diene monomers such as 3-pentadiene; aromatic polyvalent vinyl compounds such as divinylbenzene and trivinylbenzene; polyvalent ethylenically unsaturated carboxylic acids such as ethylene glycol diacrylate, trimethylolpropane triacrylate and propylene glycol diacrylate Acid ester monomer; and the like. Of these monomers,
In order to improve the balance between elasticity and strength of the flexographic plate, a conjugated diene, particularly 1,3-butadiene or isoprene is preferably used. The amount of the conjugated diene is usually 40 to 90 based on all the monomers used to obtain the hydrophilic copolymer.
% By weight, preferably 50-80% by weight. When it is less than 40% by weight, the strength and elasticity of the photosensitive elastomer composition are lowered. If it exceeds 90% by weight, the relief development speed of the flexographic plate is lowered.

The amount of the hydrophilic copolymer is usually 35 to 80 parts by weight, preferably 40 to 70 parts, based on 100 parts by weight of the total amount of the thermoplastic elastomer and the hydrophilic copolymer described below.
Parts by weight.

The thermoplastic elastomer which is a component of the photosensitive elastomer composition may be the same as that which can be compounded in the layer of the adhesive composition. Of these, block copolymers are preferred. The amount of the thermoplastic elastomer in the photosensitive elastomer composition is 20 to 65 parts by weight, preferably 30 to 60 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer and the hydrophilic copolymer. If it exceeds 65 parts by weight, the relief developing speed of the flexographic printing plate decreases. On the contrary, if it is less than 20 parts by weight, the water-based ink resistance of the flexographic printing plate is lowered.

The photopolymerizable ethylenically unsaturated monomer which is a component of the photosensitive elastomer composition is the same as the photopolymerizable ethylenically unsaturated monomer which can be blended in the adhesive composition. Can be mentioned. The amount of the photopolymerizable ethylenically unsaturated monomer is 5 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer and the hydrophilic copolymer. If the amount is less than 5 parts by weight, curing of the photosensitive elastomer composition due to actinic light does not proceed sufficiently, so that the mechanical strength of the flexographic plate decreases. On the other hand, if it exceeds 100 parts by weight, the elasticity and solvent resistance of the flexographic printing plate deteriorate.

The photopolymerization initiator which is a component of the photosensitive elastomer composition may be the same as the photopolymerization initiator which can be incorporated in the layer of the adhesive composition. The amount of the photopolymerization initiator is 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the total amount of the thermoplastic elastomer and the hydrophilic copolymer. If the amount is less than 0.1 parts by weight, curing of the photosensitive elastomer composition due to actinic light does not proceed sufficiently, so that the mechanical strength of the flexographic plate decreases. On the other hand, if it exceeds 10 parts by weight, the photopolymerization rate decreases.

The photosensitive elastomer composition may contain a plasticizer, a storage stabilizer and the like, if necessary.

As the plasticizer, hydrocarbon oils such as naphthene oil and paraffin oil; polystyrene or polyacrylate having a molecular weight of 3000 or less; liquid 1,2-polybutadiene,
Liquid 1,4-polybutadiene and terminal modified products thereof;
Examples include liquid acrylonitrile-butadiene copolymer, liquid styrene-butadiene copolymer, and carboxylated products thereof.

Examples of storage stabilizers are phenols such as hydroquinone, pyrogallol, p-methoxyphenol, t-butylcatechol, 2,6-di-t-butyl-p-cresol and benzoquinone; benzoquinone, p-toluquinone, p- Examples thereof include quinones such as xyloquinone; amines such as phenyl-α-naphthylamine.

In the photosensitive flexographic printing original plate of the present invention, the photosensitive elastomer composition layer usually has a plate shape. The thickness of the photosensitive elastomer composition layer is usually
It is 1 to 7 mm, preferably 2 to 6 mm.

The photosensitive elastomer composition layer is usually kneaded using a kneader such as a kneader or roll mill,
Obtained by molding. The order of kneading is not particularly limited, in order to obtain a uniform composition, after kneading the hydrophilic copolymer and the thermoplastic elastomer, the photopolymerizable ethylenically unsaturated monomer and the photopolymerization initiator It is better to add and knead.

A base film, a slip film and a protector film are preferably laminated on the photosensitive flexographic printing original plate of the present invention.

The base film is laminated so as to be in contact with the layer of the adhesive composition of the photosensitive flexographic printing original plate, and protects the layer of the adhesive composition. The base film is peeled off when the photosensitive flexographic printing original plate is laminated on the support plate. The base film is made of a flexible resin. Examples of the flexible resin include polyethylene terephthalate, polypropylene, polyimide, polyamide and the like.
Further, in order to facilitate the peeling of the base film from the layer of the adhesive composition when laminating the photosensitive flexographic printing original plate on the support plate, it is preferable to provide a release layer on the surface of the base film that contacts the layer of the adhesive composition. . The release layer is usually formed of silicone, alkyd resin, urethane resin, or the like.

The slip film is laminated so as to be in contact with the layer of the photosensitive elastomer composition of the photosensitive flexographic printing original plate. Since the surface of the photosensitive elastomer composition layer usually has a strong adhesiveness, when the original image film is directly attached to the surface, bubbles enter between the photosensitive elastomer composition and the original image film, resulting in irregular refraction of active light. When this occurs, the reproducibility of the relief deteriorates, and there is a problem in that the original film adhered to the surface of the photosensitive elastomer composition layer cannot be reused. By laminating the slip film, the above problem is solved. The slip film is formed of a non-adhesive water-soluble polymer compound. Examples of the water-soluble polymer include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, polyethylene oxide, polyethyleneimine and their derivatives. Of these, polyvinyl alcohol is preferred, with a saponification degree of 6 in particular.
Polyvinyl alcohol having a viscosity of 5 to 80 mol% and a viscosity of 10 cp or less when measured with a Hebler viscometer at a temperature of 20 ° C. is preferable. The thickness of the slip film is usually
It is 0.5 to 10 μm. If it is too thick, poor adhesion with the original film tends to occur. If it is too thin, the effect of preventing sticking of the original film is reduced. In order to laminate the slip film on the photosensitive flexographic printing original plate, a method of directly coating a solution of a water-soluble polymer compound on the photosensitive elastomer composition can be adopted, but usually, a protector film described below is water-soluble. After obtaining a laminated film of a protector film and a slip film by forming a slip film by coating a solution of a photosensitive polymer compound, the laminated film is contacted with the layer of the photosensitive elastomer composition. A crimping method is adopted.

The protector film is laminated on the photosensitive elastomer composition layer side of the photosensitive flexographic printing original plate. Usually, the slip film is laminated so as to be interposed between the photosensitive elastomer composition layer and the protector film. The protector film is for preventing the photosensitive elastomer composition layer from being deformed by an external force when the printing plate is conveyed or stored, and is peeled off before the original film is attached to the photosensitive flexographic printing original plate. It is a thing. The protector film is made of a flexible resin. Examples of the flexible resin include polyethylene terephthalate film, polyethylene film, polypropylene film, polystyrene film and the like. Further, in order to make it easier to peel the protector film from the photosensitive flexographic printing original plate before the original film is attached to the photosensitive flexographic printing original plate, it is preferable to provide a release layer on one surface of the protector film in contact with the original plate. The release layer is usually silicone, alkyd resin,
It is made of urethane resin or the like. The thickness of the protector film is usually 75 to 200 μm, preferably 100 to
It is 150 μm. If it is too thin, the film strength will be insufficient,
The formed photosensitive rubber plate is easily deformed. On the other hand, if the film is too thick, the film strength will be too strong and it will be difficult to peel the film from the layer of the photosensitive elastomer composition.

The photosensitive flexographic printing original plate of the present invention can be obtained by laminating a photosensitive elastomer composition layer and an adhesive composition layer on each other. For laminating and laminating the layer of the photosensitive elastomer composition and the layer of the adhesive composition, the plate-shaped photosensitive elastomer composition may be coated with an organic solvent solution of the adhesive composition and laminated. Usually, after coating the adhesive composition on the base film, the base film and the photosensitive elastomer composition are superposed so that the photosensitive elastomer composition comes into contact with the side of the base film coated with the adhesive composition. It is obtained by pressing with a pressing machine, a rubber roller or the like.

To coat the adhesive composition on the base film, an organic solvent solution of the adhesive composition is applied to the base film by using a bar coater, a Mayer bar, a comma coater, a gravure coater, a reverse roll coater or the like. The organic solvent in the coating film is volatilized. After coating the adhesive composition on the base film, and before pressing on the photosensitive elastomer composition, contact the layer of the adhesive composition to protect the layer of the adhesive composition coated on the base film. As described above, it is preferable to cover with a separator (release film). The separator is usually formed of polyethylene, polyamide, polyester or the like.

At the same time as the base film having the adhesive composition layer formed on the photosensitive elastomer composition is pressure-bonded and laminated, the laminated film of the protector film and the slip film is pressure-bonded to the photosensitive elastomer composition. be able to.

The photosensitive flexographic printing plate of the present invention is prepared by laminating a support plate and the photosensitive flexographic printing plate precursor such that the layer of the adhesive composition of the photosensitive flexographic printing plate precursor is in contact with the support plate. It will be.

The support plate is usually a plate made of an elastomer. Examples of the elastomer forming the support plate include natural rubber, synthetic rubber, and soft vinyl chloride resin. It is also possible to use a foam plate as the support plate for adjusting the printing pressure. The thickness of the support plate is usually 2 to 9
mm, preferably 3 to 7 mm.

In order to laminate the support plate and the photosensitive flexographic printing original plate, an adhesive may be applied to the support plate or the layer of the adhesive composition of the photosensitive flexographic printing original plate to bond them together. Alternatively, a method of applying an organic solvent to the layer of the adhesive composition to partially dissolve or swell the adhesive composition, and then laminating the adhesive composition is suitable for increasing the dimensional stability. Before laminating the support plate and the photosensitive flexographic printing original plate, the support plate of the photosensitive flexographic printing original plate is usually irradiated with active light on the side of the photosensitive flexographic printing original plate on which the adhesive composition is laminated. Harden the bonded surface.

The organic solvent used for laminating the support plate and the photosensitive flexographic printing original plate may be any solvent which dissolves or swells the adhesive composition, and is, for example, a carboxyl group such as ethyl acetate, methyl acetate or butyl acetate. Acid alkyl ester; acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone; benzene,
And aromatic hydrocarbons such as toluene and xylene; alicyclic hydrocarbons such as cyclopentane and cyclohexane; halogenated hydrocarbons such as trichloroethane, trichloroethylene, methylene chloride and carbon tetrachloride. Among these organic solvents, carboxylic acid alkyl esters, aromatic hydrocarbons or ketones, especially ethyl acetate, toluene or methyl ethyl ketone are preferable because they have high peel strength between the indicator plate and the photosensitive flexographic printing original plate and are excellent in dimensional stability.

[0043]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The parts and% in the examples and comparative examples are based on weight.

The photosensitive flexographic printing original plate and the photosensitive flexographic printing plate were evaluated based on the following test methods.

[Peeling strength test] The peeling strength between the photosensitive flexographic printing original plate and the supporting plate of the photosensitive flexographic printing plate was determined by JIS.
-K6301 (7) It carried out based on the peeling test (rectangular test piece). The tester is a model TC manufactured by Shinko Communication Industry Co., Ltd.
M-200 was used. It should be noted that the larger the peel strength value, the better the photosensitive flexographic printing plate.

[Dimensional Stability Test] The photosensitive flexographic printing plate was visually observed and evaluated according to the following indexes. ○: The dimensions of the printing original plate and the support plate are almost the same as the dimensions before lamination. △: The dimensions of the support plate are slightly smaller than the dimensions before lamination, but can be fixed to the printing roll syringe. The printed image is not distorted. X: The size of the support plate is significantly reduced as compared with the size before lamination, and it is difficult to fix the support plate to the printing roll syringe, and the printed image is distorted.

Example 1 Hydrophilic copolymer (monomer composition = 60% butadiene, 9% methyl acrylate, 20 ethylene glycol phosphate)
%, Styrene 10% and divinylbenzene 1%) 65
Parts, polystyrene-polybutadiene-polystyrene type block copolymer 35 parts, liquid polybutadiene (Nisso PB, B1000 manufactured by Nippon Soda) 50 parts and 2,6-di-
After kneading 0.2 parts of t-butyl-p-cresol in a kneader at 150 ° C. until uniform, the kneader temperature was lowered to 120 ° C., and 10 parts of 1,6-hexanediol diacrylate and 1,6- 5 parts of hexanediol dimethacrylate, 1 part of benzoin methyl ether and 0.02 part of methylhydroquinone were added and further kneaded to obtain a photosensitive elastomer composition.

On the other hand, 100 parts and 1,6 of a block copolymer (Clayton TR-1101 manufactured by Shell Kagaku Co.) consisting of polystyrene blocks and polybutadiene blocks.
10 parts of hexanediol dimethacrylate was dissolved in 100 parts of toluene to obtain a solution of an adhesive composition having a solid content of 47.6%. A 125 μm-thick polyethylene terephthalate film (hereinafter sometimes referred to as a base film) coated with silicone was coated with a solution of the adhesive composition using a bar coater at 0.1 mm intervals, and then at room temperature for 10 minutes. Leave it to stand, and then leave it in a dryer at 70 ° C for 5 minutes to give a thickness of about 5 on the polyethylene terephthalate film.
A thin film of an adhesive composition having a thickness of 0 μm (hereinafter sometimes referred to as an adhesive composition layer) was formed.

Separately, the saponification degree is 70 mol% and the temperature is 20.
10 parts of polyvinyl alcohol having a Hebrewer viscosity of 8 cp at 0 ° C. was dissolved in 90 parts of water to obtain an aqueous polyvinyl alcohol solution. A 125 μm thick polyethylene terephthalate film coated with silicone (hereinafter sometimes referred to as a protector film) was coated with the polyvinyl alcohol aqueous solution using a 1/1000 inch coater, and then left in a dryer at 110 ° C. for 1 minute. Then, a thin film of polyvinyl alcohol (hereinafter, sometimes referred to as a slip film) having a thickness of about 3 μm was formed on the polyethylene terephthalate film.

Next, the photosensitive elastomer composition was sandwiched between two sheets of a 125 μm thick polyethylene terephthalate film (hereinafter referred to as a molding film), and molded into a plate having a thickness of 3 mm using a vacuum press machine. . The molded film was in close contact with the plate-shaped photosensitive elastomer composition. Next, after peeling one molding film from the photosensitive elastomer composition, a protector film having a slip film formed on the surface thereof and a photosensitive elastomer composition are superposed so that the slip film contacts the photosensitive elastomer composition. They were combined and pressure-bonded using a roller. Next, after peeling off the other molding film, the base film having the adhesive composition layer formed on the surface thereof and the photosensitive elastomer composition are laminated so that the adhesive composition layer contacts the photosensitive elastomer composition. The layers were combined and pressure-bonded using a roller to obtain a photosensitive flexographic printing original plate.
The adhesive composition layer and the slip film are laminated in close contact with the photosensitive elastomer composition, and when the base film or the protector film is peeled off, the adhesive composition layer or the slip film is peeled off from the base film or the protector film, and is exposed to light. Does not peel from the elastomeric composition.

Next, the base film pressed to the photosensitive flexographic printing original plate was peeled off to expose the adhesive composition layer, and then the exposed surface was exposed to an ultraviolet light (illuminance 5 mW / cm ² , exposure wavelength 320 to 400 nm). ) Was used to irradiate ultraviolet rays for 2 minutes. Then, ethyl acetate was sprinkled on a rubber-made supporting plate (made by Meiwa Rubber Co., Ltd.) having a thickness of 4 mm, and then the photosensitive flexographic printing original plate after irradiation with the ultraviolet rays and the supporting plate were contacted with the adhesive composition layer. As described above, they were closely adhered to each other using a rubber roller and then left for 30 minutes to obtain a photosensitive flexographic printing plate. Table 1 shows the evaluation results of the peel strength and the dimensional stability of this photosensitive flexographic printing plate.

Example 2 Except that the block copolymer used in the adhesive composition in Example 1 was replaced with a block copolymer consisting of polystyrene blocks and polyisoprene blocks (Zeon Corporation, Quintac 3530). In the same manner as in Example 1, a photosensitive flexographic printing original plate and a photosensitive flexographic printing plate were obtained. The evaluation results are shown in Table 1.

Example 3 A photosensitive flexographic printing original plate and a photosensitive flexographic printing plate were prepared in the same manner as in Example 1 except that the 1,6-hexanediol dimethacrylate used in the adhesive composition in Example 1 was not added. Obtained. The evaluation results are shown in Table 1.

Examples 4 to 6 A photosensitive flexographic printing original plate and a photosensitive flexographic printing plate were prepared in the same manner as in Example 1 except that the organic solvent shown in Table 1 was used instead of the ethyl acetate sprayed on the support plate. Got The evaluation results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 1 except that the adhesive composition layer was not formed on the base film, a photosensitive flexographic printing original plate and a photosensitive flexographic printing plate were obtained. The evaluation results are shown in Table 1.

Comparative Example 2 The same procedure as in Example 1 except that an adhesive (DA-753 manufactured by Nogawa Chemical Co., Ltd.) was used in place of the ethyl acetate sprayed on the support plate in Comparative Example 1, and a photosensitive flexographic printing original plate and a photosensitive plate were prepared. A flexible flexographic printing plate was obtained. The evaluation results are shown in Table 1.

[0057]

[Table 1]

From the above, it can be seen that the one obtained by adhering to the supporting plate with an organic solvent without forming an adhesive composition layer and laminating (Comparative Example 1) has a low peel strength. Further, it can be seen that the dimensional stability is remarkably poor in the laminate (Comparative Example 2) which is adhered to the supporting plate with an adhesive and laminated. On the other hand, it can be seen that the photosensitive flexographic printing original plate (Example) in which the layer of the adhesive composition is laminated on the layer of the photosensitive elastomer (Example) has high peel strength and excellent dimensional stability. In particular, a layer of the adhesive composition is blended with a block copolymer consisting of a polystyrene block and a polybutadiene block and a photopolymerizable ethylenically unsaturated monomer, a carboxylic acid alkyl ester as an organic solvent,
Using aromatic hydrocarbons or ketones (Example 1,
It can be seen that 4 and 5) have high peel strength.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a laminated state of a photosensitive flexographic printing original plate of the present invention.

FIG. 2 is a cross-sectional view showing a laminated state of the photosensitive flexographic printing plate of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Layer of photosensitive elastomer composition 2 ... Layer of adhesive composition 3 ... Slip film 4 ... Base film 5 ... Support plate 7 ... Protector film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/11 503 G03F 7/11 503

Claims (4)

[Claims] 1. A laminate comprising a layer of a photosensitive elastomer composition that dissolves or swells when contacted with an aqueous solvent and a layer of an adhesive composition that dissolves or swells when contacted with an organic solvent. Characteristic photosensitive flexographic printing original plate. 2. A photosensitive material which is dissolved or swelled by contact with an aqueous solvent after a base film is coated with an adhesive composition which is dissolved or swelled by contact with an organic solvent to form a layer of the adhesive composition. The photosensitive flexographic printing original plate according to claim 1, wherein a base film is adhered to the elastomer composition so that the layer of the adhesive composition is in contact with the elastomer composition to laminate the photosensitive elastomer composition and the adhesive composition. Manufacturing method. 3. A photosensitive flexographic printing method comprising laminating a support plate and the photosensitive flexographic printing plate precursor such that a layer of the adhesive composition of the photosensitive flexographic printing plate precursor according to claim 1 is in contact with the supporting plate. Edition. 4. The support plate or the layer of the adhesive composition of the photosensitive flexographic printing original plate according to claim 1 is brought into contact with an organic solvent, and then the support plate and the layer of the adhesive composition are brought into close contact with each other to form a support plate. A process for producing a photosensitive flexographic printing plate, which comprises laminating the photosensitive flexographic printing plate and the photosensitive flexographic printing original plate.