JP2013210473A - Photosensitive resin letterpress printing plate precursor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin letterpress printing plate precursor excellent in handling property, in which a cover film is easily peeled when the film is to be peeled for platemaking, but the cover film is not peeled during manufacturing or handling the precursor.SOLUTION: A photosensitive resin letterpress printing plate precursor comprises: at least a support body; a photosensitive resin layer; an adhesion preventing layer; a peeling force adjusting layer; and a cover film with a matted surface, successively layered. The peeling force adjusting layer includes an acrylic polymer obtained by polymerizing a monomer having an aromatic benzene ring as a skeleton and a vinyl monomer copolymerizable with the monomer having the aromatic benzene ring as a skeleton, with the content of the acrylic polymer being 60 mass% or more with respect to the components of the peeling force adjusting layer.

Description

The present invention relates to a printing original plate for photosensitive resin letterpress. More specifically, the present invention relates to a printing original plate for a photosensitive resin relief plate having excellent cover film peelability.

In the printing plate for photosensitive resin relief printing, the mask is attached to the cover film after the cover film is peeled off. When the cover film is mat-treated, the cover film is removed from the strength of adhesion between the mat-treated film and the anti-adhesion layer. It may become difficult to peel off, and the anti-adhesion layer may be peeled off together with the cover film, or the photosensitive resin layer may be damaged due to the force applied to peel off the cover film. However, if a general release agent is applied to the cover film and the adhesion to the anti-adhesion layer is lowered, the cover film will be peeled off during manufacturing, transportation, and handling up to plate making, and protection of the photosensitive layer, which is the purpose of the cover film Was insufficient.

As a measure for improving the peelability of the cover film, a method of adding an auxiliary agent to the adhesion preventing layer has been proposed (for example, Patent Document 1). However, in the case of water development, such a conventional technique has a problem in that as the number of plates to be developed increases, the concentration of salt in the developer increases, causing development failure.
In addition, in the CTP plate in which an infrared absorbing layer is provided on the plate surface, an anionic surfactant is applied to a peeling force adjusting layer made of polyvinyl alcohol (for example, Patent Document 2) or a peeling force adjusting layer made of polyvinyl alcohol. There is known a technique that facilitates peeling by adding. (For example, Patent Document 3) However, such a technique is a technique for improving the peelability of the cover film and the peel force adjusting layer, and when the cover film is peeled off in a printing plate that does not use an infrared absorption layer, the peel film and the peel force are removed. There is a problem in that the function of the anti-adhesion layer is hindered because it peels between the adjustment layers and the peel force adjustment layer remains on the anti-adhesion layer.
Therefore, in the conventional technology, a photosensitive relief printing plate that is easy to peel off when the cover film is peeled off at the time of plate making but has excellent handleability without peeling off the cover film at the time of manufacturing, transportation, and handling up to plate making. The printing original plate was not obtained.

JP-A-8-234439 JP 2004-163925 A JP 2009-139599 A

The present invention has been made against the background of such prior art problems. That is, the object of the present invention is a photosensitivity that is easy to peel off when the cover film is peeled off at the time of plate making, but has excellent handleability without being peeled off at the time of manufacture, transportation and handling up to plate making. It is to provide a printing original plate for letterpress.

As a result of intensive studies to achieve such an object, the present inventors have found that at least a support, a photosensitive resin layer, an anti-adhesion layer, a peeling force adjusting layer, and a cover film having a matte surface are sequentially laminated. An acrylic polymer obtained by polymerizing a monomer having a benzene ring as a skeleton and a vinyl monomer copolymerizable with a monomer having an aromatic benzene ring as a skeleton. It has been found that the problem can be solved by using a photosensitive letterpress printing original plate characterized in that it is contained and the content is 60% by mass or more with respect to the component in the peeling adjustment layer.

According to a preferred embodiment of the present invention, the release force adjusting layer is a photosensitive resin printing original plate in which a vinyl monomer copolymerizable with a monomer having a benzene skeleton contains active hydrogen in the molecule, and more preferably, the peeling force adjusting layer. Is a printing original plate for photosensitive letterpress, comprising at least an acrylic polymer and a crosslinking component, wherein the crosslinking component is a polyvalent isocyanate.

The photosensitive printing plate precursor of the present invention is sensitive because it can be easily handled when peeling the cover film during plate making, but can be handled without being peeled off during production, transportation and handling up to plate making. It is useful as a printing original plate for a letterpress plate.

Hereinafter, the photosensitive relief printing original plate of the present invention will be described in detail.

  The relief printing plate precursor of the present invention is a photosensitive relief printing plate precursor comprising at least a support, a photosensitive resin layer, an anti-adhesion layer, a peeling force adjusting layer, and a cover film having a matte surface. And an acrylic polymer obtained by copolymerizing a monomer having a benzene ring as a skeleton and a vinyl monomer copolymerizable with a monomer having an aromatic benzene ring as a skeleton on the mat-treated cover film, It has the structure which provided the peeling force adjustment layer which is 60 mass% or more with respect to the component in a peeling adjustment layer.

The cover film used in the original plate of the present invention is flexible but is preferably a material having excellent dimensional stability, and examples thereof include thermoplastic resin supports such as polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. I can do it. Among these, a polyethylene terephthalate film having excellent dimensional stability and sufficiently high viscoelasticity is particularly preferable. Examples of the matting treatment method for the film surface include a chemical mat using an alkali treating agent, a sand mat using sand blasting, an embossing mat using embossing, and a coating mat using fine particle coating. The thickness of the support is from 50 to 350 μm, preferably from 100 to 250 μm, from the viewpoint of mechanical properties, shape stability, or handleability during plate making.

The peeling force adjusting layer used in the original plate of the present invention is an acrylic polymer obtained by polymerizing a monomer having a benzene ring as a skeleton and a vinyl monomer copolymerizable with a monomer having an aromatic benzene ring as a skeleton in the peeling adjusting layer. It contains 60 mass% or more with respect to the component.

The thickness of the peeling force adjusting layer is 0.01 μm to 2 μm, preferably 0.03 μm to 1.5 μm, and more preferably 0.05 μm to 1 μm. If the thickness is less than 0.01 μm, the peeling force cannot be adjusted, and if it exceeds 2 μm, streaks are likely to occur during production, which is not preferable.

  Examples of the benzene ring-containing monomer used in the peel force adjusting layer include benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, methylphenoxyethyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3 -Phenoxypropyl acrylate, 2-acryloyloxyethylphthalic acid, 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid, neopentyl glycol acrylate benzoate, 2-hydroxy-4-acryloyloxybenzophenone, 2 -Hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4- (2-acryloyloxy) ethoxybenzophenone, 2-hydro Cy-4- (2-methacryloyloxy) ethoxybenzophenone, 2- [2′-hydroxy-5 ′-(methacryloyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-5 ′-(acryloyloxy) phenyl] benzotriazole 2- [2′-hydroxy-3′-methyl-5 ′-(acryloyloxy) phenyl] benzotriazole, but is not limited thereto.

Examples of vinyl monomers copolymerizable with monomers having a benzene ring as a skeleton include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, butoxy acrylate, butoxy methacrylate, acrylic acid, Methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 2-acryloyloxyethyl-succinic acid, 2 -Methacryloyloxyethyl-succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methyl It can be mentioned methacryloyloxyethyl hexahydrophthalic acid. Among them, a copolymerizable monomer containing active hydrogen in the molecule is preferable because it can react with a crosslinking component such as a polyvalent isocyanate compound.

The copolymerizable monomer containing active hydrogen in the molecule includes acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl. Acrylate, 2-hydroxybutyl methacrylate, 2-acryloyloxyethyl-succinic acid, 2-methacryloyloxyethyl-succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-methacryloyloxyethyl hexahydrophthalic acid I can list them.

  As a method for producing the acrylic polymer, a known method can be used. For example, copolymerization can be performed by solution polymerization, suspension polymerization, emulsion polymerization, or the like. In the case of solution polymerization, it is desirable to use an aromatic solvent such as toluene, ethyl acetate, or methyl ethyl ketone, an ester solvent, or a ketone solvent as a solvent. As the polymerization initiator, azobisisobutylnitrile or the like can be used. A chain transfer agent such as n-dodecyl mercaptan or lauryl mercaptan may be added as necessary.

  The peeling force adjusting layer used in the present invention is preferably crosslinked by adding a crosslinking component to the acrylic polymer. The cross-linking component is preferably a polyvalent isocyanate from the viewpoint of reactivity. The polyvalent isocyanate compound that can be used in the present invention is not particularly limited as long as it has two or more isocyanate groups in the molecule. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, mexamethylene diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl diisocyanate, phenyl diisocyanate, 6-isocyanato It is obtained by adding hexylcarbamic acid 6- [3- (6-isocyanatohexyl) -2,4-dioxo-1,3-diazetidin-1-yl] hexyl, and these polyvalent isocyanates to trimethylolpropane and the like. And adduct bodies that can be used.

  As a component used for a peeling force adjustment layer, other components can be mix | blended in the range which does not affect peeling force other than an acrylic polymer and a crosslinking component. For example, an acrylic polymer having no aromatic benzene ring as a skeleton, a polymer compound compatible with the acrylic polymer other than the acrylic polymer, an ultraviolet absorber, a colorant, and the like can be given.

  As a method for providing the peeling force adjusting layer used in the present invention, a known method is possible, but a coating method is preferable from the viewpoint of productivity.

In the printing original plate of the present invention, an anti-adhesion layer is provided between the photosensitive resin and the peeling force adjusting layer. The anti-adhesion layer needs to be transparent for exposure through a mask film, and it is important that it is quickly dissolved and removed by the developer of the photosensitive layer during development after exposure. If the solubility in the developer is not sufficient, it may cause uneven development of the photosensitive layer. Examples of the substance constituting the anti-adhesion layer satisfying the above conditions include cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, polyacrylamide, polyethylene oxide, polyvinylidene chloride, and polyethyleneimine. Of course, the anti-adhesion layer is required to be transparent to actinic rays.

The printing original plate of the present invention can be applied to both a flexographic plate and a letterpress plate, and those suitable for the photosensitive resin layer can be used. A suitable example of the flexographic plate is one based on a rubber component. As the letter press plate, a polyamide resin plate, a polyether urea urethane resin plate, a polyvinyl alcohol resin plate and the like are preferable, and among these, a plate which can be developed with water is more preferable.

  The photosensitive resin layer used in the original plate of the present invention contains at least a soluble polymer, a photopolymerizable unsaturated group-containing monomer, and a photopolymerization initiator.

The soluble polymer used in the present invention refers to a polymer that can be dispersed or dissolved in a solvent (developer), and particularly a polymer that can be dispersed or dissolved in water. Further, the number average molecular weight is preferably 5,000 or more, particularly 10,000 or more. For example, polyamide, polyurethane, polyester, polyvinyl pyrrolidone, cellulose derivative, polybutadiene copolymer and the like can be mentioned. Moreover, the polymer which introduce | transduced the photopolymerizable unsaturated group into these polymers can also be used.
The content of the soluble polymer is preferably 40 to 80% by weight, more preferably 50 to 70% by weight in the photosensitive resin composition. When the content is less than 40%, the composition is likely to cold flow and the physical properties may be deteriorated. On the other hand, if it exceeds 80% by weight, the sensitivity may be lowered or the development time may be prolonged. Further, the crosslinking density is lowered, and the water resistance and solvent resistance of the image may be lowered.

  The photopolymerizable unsaturated group-containing monomer used in the present invention is a monomer containing at least one photopolymerizable unsaturated group in the molecule, and conventionally known monomers can be used, for example, acrylic acid, Methacrylic acid, itaconic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, acrylamide, methacrylamide, N-methylol acrylamide, N-acroylmorpholine, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Glycerol di (meth) acrylate, and also polyvalent glycidyl ethers such as ethylene glycol diglycidyl ether and trimethylolpropane triglycidyl ether, unsaturated carboxylic acids (acrylic acid, methacrylic acid, etc.) and unsaturated alcohols Polyethylenic (meth) acrylate, glycidyl (meth) acrylate and other unsaturated epoxy compounds obtained by addition reaction of ethylenically unsaturated bonds and compounds having active hydrogen, and compounds having active hydrogen such as carboxylic acid and amine Addition reaction products, unsaturated polyesters, unsaturated polyurethanes, and the like. These monomers may be used alone or in combination of two or more.

  The content of the photopolymerizable unsaturated group-containing monomer is preferably 5 to 60% by weight, more preferably 15 to 40% by weight in the photosensitive resin composition. When the content is less than 5% by weight, the curing rate by photopolymerization is inferior, and exposed image portions such as fine lines, small independent points, small type letters and fine halftone dots are difficult to remain after development, and conversely 60% by weight. Exceeding this ratio is not preferred because curing shrinkage may increase and physical properties of the image may deteriorate.

  Examples of the photopolymerization initiator include benzophenones, benzoins, acetophenones, benzyls, benzoin alkyl ethers, benzyl alkyl ketals, anthraquinones, thioxanthones, and the like. Specific examples include benzoin, acetophenone, benzyl, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, benzyl diethyl ketal, and benzyl diisopropyl ketal.

  The content of the photopolymerization initiator is preferably 0.05 to 5% by weight, more preferably 0.1 to 2.0% by weight in the photosensitive resin composition. When the content is less than 0.05% by weight, it is difficult to initiate photopolymerization. Conversely, when the content exceeds 5% by weight, the photopolymerization of the fragrance of the photosensitive layer using the composition deteriorates and is thin. The exposed image portion such as a line, a small independent point, a small type or a fine halftone dot tends to be lost, which is not preferable.

The support used for the printing original plate of the present invention is preferably a material that is flexible but excellent in dimensional stability. For example, a metal support such as steel, aluminum, copper, nickel, polyethylene terephthalate film, polyethylene Mention may be made of thermoplastic resin supports such as phthalate films, polybutylene terephthalate films, or polycarbonate films. Among these, a polyethylene terephthalate film having excellent dimensional stability and sufficiently high viscoelasticity is particularly preferable. The thickness of the support is from 50 to 350 μm, preferably from 100 to 350 μm, from the viewpoint of mechanical properties, shape stability, or handleability during printing plate making. Further, if necessary, a known adhesive layer may be provided in order to improve the adhesion between the support and the photosensitive resin layer.

Although it does not specifically limit as a manufacturing method of the printing original plate for photosensitive relief printing plates of this invention, Generally, it manufactures as follows.
The method for forming the peel strength adjusting layer is not particularly limited, but for ease of thin film formation, a method of removing the solvent after coating the cover film in a state where the peel strength adjusting layer component is dissolved in the solvent is preferably performed. The solvent is not particularly limited, but organic solvents such as toluene and 2-butanone are mainly used.
Although the formation method of an adhesion prevention layer is not specifically limited, The method of dissolving an adhesion prevention layer component in a suitable solvent, coating the above-mentioned peeling force adjustment layer, and removing a solvent is performed preferably.
Thereby, the laminated body which consists of a cover film, a peeling force adjustment layer, and an adhesion prevention layer is obtained.
Further, separately from this, a photosensitive resin layer is formed on the support by coating, and the other laminate is produced. The two laminates thus obtained are laminated so that the photosensitive resin layer is adjacent to the anti-adhesion layer under pressure and / or heating.

As a method for producing a relief printing plate from the photosensitive relief printing plate precursor of the present invention, first, the cover film is removed from the photosensitive relief printing plate precursor. Thereafter, when a mask film having a transparent image portion is adhered and superimposed on the anti-adhesion layer, and exposure is performed by irradiating an actinic ray from the mask film, the exposed portion is cured and insolubilized. For the actinic ray, a light source such as a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, a xenon lamp, or a chemical lamp, usually centered on a wavelength of 300 to 400 nm, can be used.
After exposure, an appropriate solvent, preferably water, particularly neutral water, is used as a solvent to dissolve and remove the non-exposed portion, whereby development can be performed quickly and a printing plate (relief plate) can be obtained. . As the developing method, it is preferable to use a spray developing device, a brush developing device, or the like.
EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not a thing limited to these Examples.

EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not a thing limited to these Examples. The evaluation method was evaluated by the following method.
[Performance evaluation]
(1) Peeling force test: A printing original plate produced as a test piece is cut into 150 mm × 50 mm, the end of the cover film is peeled off with a fingertip, set on a tensile testing machine, pulled to 90 ° C. at a rate of 1000 mm / min, and peeled off. The force was measured.
-Peelability test: An A-1 size printing original plate was placed on a desk, and the peeling method was evaluated when the cover film was peeled off with the other hand while holding the printing original plate with one hand.
○: It was able to peel off smoothly.
(Triangle | delta): It was difficult to grasp the opportunity for peeling.
X: It was difficult to peel off and could not be peeled off at once.
Cutting detachability: A-4 size printing original plate is cut with a press cutter, and the cover film is peeled off at the cut portion.
○: peeling of the edge at the time of cutting is 5 mm or less Δ: peeling of the edge at the time of cutting is less than 10 mm ×: peeling of the edge at the time of cutting is 10 mm or more

Example 1
<Creation of peel force adjusting layer polymer>
Into a flask equipped with a nitrogen inlet and a stirrer, add 50 g of benzyl methacrylate as a monomer used for polymerization, 46 g of methyl acrylate, 4 g of butyl acrylate, 1.0 g of n-dodecyl mercaptan as a chain transfer agent, and 100 g of toluene as a solvent, and introduce nitrogen. The temperature is raised to 50 ° C. while blowing nitrogen from the tube. Thereafter, 0.3 g of azobisisobutyronitrile as a polymerization initiator is added and stirred. After stirring for 1 hour, the temperature was raised to 70 ° C. and the reaction was carried out for 8 hours to obtain a polymer solution.
<Preparation of peeling force adjustment layer>
50 g of toluene and methyl ethyl ketone were added to 1 g of the obtained polymer solution, and the mixture was stirred at 25 ° C. for 1 hour to obtain a peeling force adjusting layer coating solution. The obtained peeling force adjusting layer coating liquid was applied to a chemical mat film (TC-5002 manufactured by Toyo Cloth Co., Ltd.) having a thickness of 100 μm with a wire bar # 6, dried at 100 ° C. for 3 minutes, and 0.05 μm. A peeling force adjusting layer was formed.
<Preparation of anti-adhesion layer>
3 g of PVA (AH-26 [manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree: 97.0 to 98.8%]) was added to 97 g of pure water, and the mixture was stirred at 90 ° C. for 1 hour. This PVA solution was applied onto the peel strength adjusting layer with a wire bar # 24 and dried at 120 ° C. for 3 minutes to obtain a laminated film in which a 1.0 μm anti-sticking layer was laminated on the peel strength adjusting layer.
<Preparation of photosensitive printing plate precursor>
50 parts by weight of ε-caprolactam, 40 parts by weight of N, N′-bisaminopropylpiperazine adipate and 10 parts by weight of 1,3-bis (aminomethyl) cyclohexane adipate are polymerized to have a melting point of 137 ° C. and a specific viscosity of 1.96. A tertiary nitrogen-containing polyamide was obtained. 55 parts of the obtained polyamide was dissolved in 200 parts by weight of methanol and 24 parts by weight of water. In this solution, 3 parts by weight of methacrylic acid, 35 mol% of trimethylolpropane triglycidyl ether, 35 mol% of acrylic acid and 65 mol% of methacrylic acid were added. 36 parts of the reaction product, 5 parts by weight of N-ethyl-p-toluenesulfonamide, 0.1 part by weight of hydroquinone monomethyl ether and 1 part by weight of benzyl dimethyl ketal were added to obtain a photosensitive resin composition solution. This photosensitive resin solution was sent to a concentrator and concentrated at 110 ° C. to obtain a photosensitive resin composition A. Next, the photosensitive resin composition A is sandwiched between the adhesive coating surface side of the support film obtained by coating 20 μm of the adhesive on a 250 μm polyethylene terephthalate film and the anti-adhesive layer coating side of the laminated film. , And heated and pressed at 100 ° C. to prepare a printing original plate for photosensitive relief printing plate having a total thickness of 950 μm.

Example 2
Peeling force adjusting layer in Example 1 The same manner as in Example 1 except that the monomer used for polymer polymerization was changed to 50 g of 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, 46 g of methyl methacrylate, and 4 g of butyl acrylate. A photosensitive printing plate precursor was prepared.

Example 3
Except that the monomer used for polymer polymerization in Example 1 was changed to 2- [2′-hydroxy-5 ′-(methacryloyloxy) phenyl] benzotriazole 40 g, methyl methacrylate 36 g, and butyl acrylate 24 g. Produced a photosensitive relief printing original plate in the same manner as in Example 1.

Example 4
Peeling force adjusting layer in Example 1 The monomer used for polymer polymerization was 2- [2′-hydroxy-5 ′-(methacryloyloxy) phenyl] benzotriazole 40 g, methyl methacrylate 36 g, butyl acrylate 24 g, and methacrylate 2-hydroxy. A photosensitive printing plate precursor was prepared in the same manner as in Example 1 except that 3 g of ethyl and 1 g of methacrylic acid were used.

Example 5
To 1 g of the peel strength adjusting layer polymer solution of Example 4, 0.002 g of dibutyltin laurate, 6- [3- (6-isocyanatohexyl) -2,4-dioxo-1,3-diisocyanatohexylcarbamic acid Diazetidin-1-yl] hexyl 0.04 g, toluene 50 g, and methyl ethyl ketone 50 g were added and stirred for 1 hour to obtain a peeling force adjusting layer coating solution. The obtained peeling force adjusting layer coating solution is applied to a chemical mat-treated PET film with a wire bar # 6 and dried at 100 ° C. for 3 minutes to form a peeling force adjusting layer on the chemical mat-treated PET. In the same manner as in Example 1, a photosensitive relief printing original plate was obtained.

Comparative Example 1
A printing original plate for photosensitive relief printing was obtained in the same manner as in Example 1 except that the anti-adhesion layer was directly coated on the chemical mat film without providing the peeling force adjusting layer.

Comparative Example 2
A printing original plate for photosensitive relief printing was obtained in the same manner as in Example 1 except that the heavy release agent Tesfine 322 (manufactured by Hitachi Chemical Co., Ltd.) was applied as the peeling force adjusting layer.

Comparative Example 3
Peeling force adjusting layer In Example 1, a photosensitive printing plate precursor was prepared in the same manner as in Example 1 except that the monomers used for polymer polymerization were changed to 56 g of methyl methacrylate and 44 g of butyl acrylate.

As is clear from Table 1, when the peeling force adjusting layer of the present invention was used, good results were obtained in each test.

  The printing original plate for photosensitive resin relief printing using the constitution of the present invention is useful as a printing plate for relief printing because it is excellent in the peelability of the cover film.

Claims (3)

At least a support, a photosensitive resin layer, an anti-adhesion layer, a peel force adjusting layer, and a cover film whose surface is matted, are laminated in order, and the release force adjusting layer is an aromatic benzene. It contains an acrylic polymer obtained by polymerizing a monomer having a ring as a skeleton and a vinyl monomer copolymerizable with the monomer having an aromatic benzene ring as a skeleton, and the content is 60 with respect to the components in the peeling control layer. The printing original plate for photosensitive resin letterpress characterized by being more than mass%. 2. The printing original plate for photosensitive resin letterpress according to claim 1, wherein the vinyl monomer copolymerizable with a monomer having an aromatic benzene ring as a skeleton contains active hydrogen in the molecule. 3. The printing original plate for a photosensitive resin letterpress according to claim 1, wherein the peeling force adjusting layer comprises at least an acrylic polymer and a crosslinking component, and the crosslinking component is a polyvalent isocyanate.