JP2018205542A - Method for manufacturing photosensitive resin plate for printing plate - Google Patents

Abstract

To provide a photosensitive resin plate for a printing plate, which shows uniform tackiness elimination property on a plate surface, achieves stabilized qualities of a printing plate and gives excellent production efficiency in printing.SOLUTION: The following steps are successively performed: a step (B-1) of irradiating a photosensitive resin plate precursor (A) for a printing plate having a support body (a) and a photosensitive resin composition layer (b) with active rays through the support body (a) to form a uniform cured layer; a step (B-2) of irradiating the photosensitive resin composition layer (b) with active rays through an image pattern to perform image exposure; a step (B-3) of developing the image by use of a developer (B) to remove an unexposed part not irradiated with the active rays; a step (B-4) of drying the plate; and a step (B-5) of removing tackiness on the surface by irradiation with the active rays. In the step (B-5), the plate is irradiated with UV-C active rays by using such an active ray source that an exposure distribution of UV-C active rays ((the minimum of the irradiation intensity of active rays)/(the maximum of the irradiation intensity of active rays)) within an exposure surface is 60% or more.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a photosensitive resin plate for a printing plate.

As the printing method, a method that enables printing by applying a three-dimensional shape to a printing plate and a method that can be printed by adding chemical characteristics are known. As a representative example of the former, letterpress printing, There is intaglio printing.
In letterpress printing, printing can be performed by attaching ink to the convex portions of the printing plate, while intaglio printing allows printing by attaching ink to the concave portions of the printing plate.
Printing plates used for letterpress printing, particularly printing plates used for flexographic printing, which is a type of letterpress printing method, are generally photosensitive resins in which a photosensitive resin composition layer is laminated on a polyester film as a support. Made from sexual composition.
Examples of a method for producing a printing plate by making a photosensitive resin plate for a printing plate using this photosensitive composition include the following methods.
First, the entire surface is exposed to ultraviolet light (back exposure) through a polyester film that is a support for the photosensitive structure to provide a thin uniform cured layer. Next, a negative film is placed on the photosensitive resin composition layer, image exposure (relief exposure) is performed on the photosensitive resin composition layer through the negative film, and the photosensitive resin composition layer is irradiated with light according to the pattern of the negative film. Harden. Thereafter, the unexposed portion (that is, the uncured portion) in the photosensitive resin composition layer is washed with a developing solution to form a desired image, that is, a relief image, and a photosensitive resin plate for a printing plate is obtained. Subsequently, a predetermined finishing process is performed to obtain a printing plate.

In recent years, printing presses have become more precise, specifically, computerized printing pressure has been digitized, making it possible to adjust with high precision, and printing plates are required to have higher plate accuracy than before. ing.
On the other hand, in order to increase the efficiency of the printing process, multi-sided printing for printing a plurality of print images on the same plate cylinder is progressing, and a technique for obtaining a desired printed material by slitting after printing has been developed.
Under such circumstances, the printing plate is becoming larger, but on the other hand, high accuracy that matches the high accuracy of the printing press has been demanded of the printing plate.
In particular, the relief depth, which indicates the height of the image area, is an important factor in the quality of the printing plate, and this variation in the relief depth is the quality in printing, specifically, the size of halftone dots, the quality of white lines. Therefore, stabilization is required.

  Also, in response to the recent increase in print quality requirements, a technology has been developed to provide a thin film that can be ablated with an infrared laser instead of the conventional negative film, and to provide a portion that is not UV cured by laser ablation. Has been.

Due to the higher resolution of infrared lasers and the higher accuracy of flexographic printing presses, higher resolution has been required for flexographic printing plates, especially in halftone printing that expresses the density of printed matter by the size of halftone dots. There is a need to improve the fineness of halftone dots that can be expressed.
As a value indicating the degree of fineness of the halftone dots, there is a numerical value represented by the number of halftone dots arranged per inch. As the unit of the number of halftone dots, a line (line / inch) is used, and in order to increase the resolution of the printing plate, the printing plate requires a high line number (line / inch) resolution. It is becoming.

Due to the higher resolution of the printing plate as described above, there is a problem in that the print quality is deteriorated due to the adhesion of impurities adhering to the printing plate during printing, for example, paper dust generated during printing on paper. . This is because printing defects that cannot be recognized by conventional resolutions can be distinguished by higher resolution.
On the other hand, printing machines capable of high-speed printing have been introduced due to demands for improving printing productivity, and the ratio of printing without removing impurities attached to the surface of the printing plate during printing has increased. There is a problem of reduction in printing productivity due to adhesion of impurities on the plate surface.

Patent Document 1 describes a method for producing a printing plate from a printing original plate, and describes a method for stabilizing the dimensions of a photopolymerized flexographic printing plate by post-exposure treatment using a high energy irradiation source. .
Patent Document 2 describes a method for performing surface treatment of a printing plate by irradiating ultraviolet rays having a wavelength of 200 to 300 nm at a certain level or more.
Patent Document 3 describes a method of irradiating a printing plate by adjusting a light amount ratio between 250 nm and 350 nm.

JP-A-4-232955 JP 2007-264178 A JP 2011-154251 A

  However, in any of the techniques described in Patent Documents 1, 2, and 3, no investigation has been made regarding the distribution of the active irradiation intensity in the step of removing the surface tack, and the tack removal of the plate surface is not performed. There is a problem that it is not performed uniformly. As a result, there is a problem that foreign matter adheres during printing and printing efficiency decreases.

  Therefore, in the present invention, in view of the above-described problems of the prior art, the tack removal property of the plate surface is uniform, the quality of the printing plate is stabilized, and the production efficiency in printing is excellent. It aims at providing the manufacturing method of the photosensitive resin plate.

In order to solve the above-mentioned problems, the present inventors have conducted extensive research on a method for producing a photosensitive resin plate for a printing plate using a photosensitive resin original plate for a printing plate. By controlling the distribution (minimum value / maximum value in a predetermined area), it was found that the quality of the photosensitive resin plate for printing plates was stabilized, and the present invention was completed.
That is, the present invention is as follows.

[1]
A method for producing a photosensitive resin plate for a printing plate using a photosensitive resin original plate (A) for a printing plate having a support (a) and a photosensitive resin composition layer (b),
Step (B-1) of irradiating the photosensitive resin original plate for printing plate (A) with actinic rays through the support (a) to provide a uniform cured layer;
Irradiating the photosensitive resin composition layer (b) with an actinic ray through an image pattern to perform image exposure (B-2);
Using the developer (B) to develop the exposed portion irradiated with actinic rays and removing the non-exposed portion not irradiated with actinic rays (B-3);
A step (B-4) of performing a drying treatment;
Irradiating actinic rays to remove surface tack (B-5);
In order,
In the step (B-5) of removing the tack on the surface, the exposure distribution of the actinic ray in the UV-C exposure surface (minimum value of irradiation intensity of actinic light / maximum value of irradiation intensity of actinic light) is 60 Irradiating UV-C actinic rays using an active light source that is at least%,
A method for producing a photosensitive resin plate for a printing plate.
[2]
In the step (B-5) of removing the tack on the surface, in addition to the irradiation with the actinic ray of UV-C, the exposure distribution of the actinic ray in the exposure surface (minimum value of the actinic ray irradiation intensity / actinic ray Using an active light source UV-A having a maximum irradiation intensity of 60% or more, UV-C irradiation and UV-A irradiation are simultaneously performed.
The manufacturing method of the photosensitive resin plate for printing plates as described in said [1].
[3]
The photosensitive resin composition layer (b) is
The manufacturing method of the photosensitive resin plate for printing plates as described in said [1] or [2] containing a thermoplastic elastomer, an ethylenically unsaturated compound, and a photoinitiator.

  According to the present invention, it is possible to produce a photosensitive resin plate for a printing plate with uniform tack removal on the surface of the plate, stabilization of the quality of the printing plate, and excellent production efficiency in printing. .

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
The present invention is not limited to the following description, and various modifications can be made within the scope of the gist thereof.

[Method for producing photosensitive resin plate for printing plate]
The method for producing a photosensitive resin plate for a printing plate of the present embodiment,
A method for producing a photosensitive resin plate for a printing plate using a photosensitive resin original plate (A) for a printing plate having a support (a) and a photosensitive resin composition layer (b),
Step (B-1) of irradiating the photosensitive resin original plate for printing plate (A) with actinic rays through the support (a) to provide a uniform cured layer;
Irradiating the photosensitive resin composition layer (b) with an actinic ray through an image pattern to perform image exposure (B-2);
Using the developer (B) to develop the exposed portion irradiated with actinic rays and removing the non-exposed portion not irradiated with actinic rays (B-3);
A step (B-4) of performing a drying treatment;
Irradiating actinic rays to remove surface tack (B-5);
In order,
In the step (B-5) of removing the tack on the surface, the exposure distribution of the actinic ray in the UV-C exposure surface (minimum value of irradiation intensity of actinic light / maximum value of irradiation intensity of actinic light) is 60 Using an active light source that is at least%, UV-C actinic rays are irradiated.

(Photosensitive resin original plate for printing plate (A))
The photosensitive resin original plate (A) for a printing plate has a support (a) and a photosensitive resin composition layer (b).

<Support (a)>
The support (a) is not limited to the following, but for example, a polyester film can be used.
Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Although the thickness of the film is not limited, a film having a thickness of 50 to 300 μm is exemplified.

<Photosensitive resin composition layer (b)>
The photosensitive resin composition layer (b) preferably contains a thermoplastic elastomer, a liquid diene, an ethylenically unsaturated compound, a photopolymerization initiator, and an auxiliary additive component as necessary, which will be described later.

[Thermoplastic elastomer]
The photosensitive resin composition layer (b) preferably contains a thermoplastic elastomer having a polymer block composed of a monovinyl-substituted aromatic hydrocarbon and a polymer block composed of a conjugated diene.
The monovinyl substituted aromatic hydrocarbon constituting the thermoplastic elastomer is not limited to the following, but examples thereof include styrene, t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-dimethyl. -P-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, vinylpyridine, p-methylstyrene, p-methoxystyrene, tertiary butylstyrene, α-methylstyrene, 1,1-diphenylethylene, etc. Is mentioned.
In particular, styrene is preferable from the viewpoint that the photosensitive resin composition layer can be molded smoothly at a relatively low temperature.
These may be used alone or in combination of two or more.
The conjugated diene constituting the thermoplastic elastomer is not limited to the following, but examples thereof include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1 , 3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like.
These may be used alone or in combination of two or more.
From the viewpoint of durability of the photosensitive resin plate for printing plates obtained by the production method of the present embodiment, butadiene is preferred as the conjugated diene.

The thermoplastic elastomer preferably has a number average molecular weight of 20,000 to 300,000, more preferably 50,000 to 200,000, from the viewpoint of viscosity at room temperature.
The number average molecular weight can be measured by gel permeation chromatography (GPC) and is expressed in terms of polystyrene equivalent molecular weight.
The block copolymer constituting the thermoplastic elastomer is, for example, a linear block copolymer represented by the following general formula group (I) and / or a straight chain represented by the following general formula group (II). It includes a chain block copolymer or a radial block copolymer.
(A-B) _n , A- (BA) _n , A- (BA) _n- B, B- (AB) _n (I)
[(AB) _k ] _m -X, [(AB) _k -A] _m -X, [(BA) _k ] _m -X, [(BA) _k -B] _m- X (II)
A represents a monovinyl substituted aromatic hydrocarbon.
B represents a conjugated diene.
X is, for example, silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyhalogenated hydrocarbon compound, carboxylic acid ester compound, polyvinyl compound, bisphenol type epoxy compound, alkoxysilane compound, halogenated silane compound, ester compound, etc. A residue of a coupling agent or a residue of an initiator such as a polyfunctional organolithium compound.
n, k, and m show an integer greater than or equal to 1, for example, 1-5.

The contents of the conjugated diene and the monovinyl-substituted aromatic hydrocarbon in the thermoplastic elastomer can be measured using a nuclear magnetic resonance apparatus ( ¹ H-NMR).
Specifically, JNM-LA400 (manufactured by JEOL, trade name) is used as a ¹ H-NMR measuring instrument, deuterated chloroform is used as a solvent, sample concentration is 50 mg / mL, observation frequency is 400 MHz, chemical shift. The measurement can be performed by using TMS (tetramethylsilane) as a reference, setting the pulse delay to 2.904 seconds, the number of scans to 64 times, the pulse width to 45 °, and the measurement temperature to 25 ° C.
In the thermoplastic elastomer, the copolymerization ratio (mass ratio) of the monovinyl substituted aromatic hydrocarbon and the conjugated diene is determined from the viewpoint of the hardness of the photosensitive resin composition layer constituting the printing plate. Diene is preferably 10/80 to 90/20, more preferably 10/90 to 85/15, and still more preferably 10/90 to 60/40.
When the ratio of the monovinyl-substituted aromatic hydrocarbon is 10 or more, sufficient hardness can be obtained in the photosensitive resin composition layer (b), and appropriate printing can be performed by normal printing pressure. When it is 90 or less, appropriate hardness can be obtained in the photosensitive resin composition layer (b), and the ink can be sufficiently transferred to the printing object in the printing process.

If necessary, the thermoplastic elastomer may be introduced with other functional groups, chemically modified such as hydrogenation, or other components may be copolymerized.
The content of the thermoplastic elastomer in the photosensitive resin composition layer (b) is the total amount of the photosensitive resin composition from the viewpoint of the durability of the photosensitive resin plate for printing plates obtained by the production method of the present embodiment. When it is 100% by mass, it is preferably 40 to 80% by mass, more preferably 45 to 80% by mass, and further preferably 45 to 75% by mass.

[Liquid diene]
The liquid diene is a compound having a liquid carbon / carbon double bond.
Here, in this specification, “liquid” of “liquid diene” means a property having the property of being easily deformed by flow and solidified into a deformed shape by cooling, and when an external force is applied. It is a term corresponding to an elastomer having the property of recovering its original shape in a short time when the external force is deformed instantaneously according to the external force and the external force is removed.
Examples of liquid dienes include, but are not limited to, liquid polybutadiene, liquid polyisoprene, modified liquid polybutadiene, modified liquid polyisoprene, liquid acrylonitrile-butadiene copolymer, liquid styrene A butadiene copolymer may be mentioned.
The liquid diene is a copolymer having a diene component of 50% by mass or more.
Further, the number average molecular weight of the liquid diene is not particularly limited as long as it is liquid at 20 ° C., but from the viewpoint of mechanical strength and handling properties of the photosensitive resin plate for printing plates obtained by the production method of the present embodiment, Preferably they are 500 or more and 60000 or less, More preferably, they are 500 or more and 50000 or less, More preferably, they are 800 or more and 50000 or less.

From the viewpoint of mechanical properties of the photosensitive resin plate for printing plates, liquid polybutadiene is preferred as the liquid diene.
The 1,2-vinyl bond content of the liquid diene, preferably liquid polybutadiene, is preferably 10% or more and 70% or less, and preferably 20% or more and 60% from the viewpoint of making the hardness of the photosensitive resin plate for printing plates appropriate. % Or less is more preferable, and 30% or more and 60% or less is more preferable.
The amount of 1,2-vinyl bond refers to 1,2-bond among 1,2-bond, 3,4-bond, and 1,4-bond conjugated diene monomers incorporated. It is the ratio of what is incorporated in the bond.
The 1,2-polybutadiene having a 1,2-vinyl bond has a high reactivity of radical polymerization because vinyl as a double bond is a side chain, and the photosensitive resin composition layer (b) This is preferable from the viewpoint of increasing the hardness. On the other hand, in the photosensitive resin plate for printing plates, since it is necessary to ensure flexibility from the viewpoint of handling properties and ink transferability in the printing process, the content of 1,2-polybutadiene should be controlled within the above range. Is preferred.

In order to improve the flexibility of the photosensitive resin plate for printing plates, it is effective to contain 1,4-polybutadiene in the liquid diene. The 1,4-polybutadiene includes cis-type 1,4-polybutadiene and trans-type 1,4-polybutadiene. 1,4-polybutadiene has a vinyl group which is a double bond in both cis type and trans type, and therefore has low reactivity in radical polymerization, and can finally produce a flexible resin. Is possible.
When a mixture of liquid polybutadienes having a plurality of different 1,2-vinyl bond amounts is used, the average value is defined as the 1,2-vinyl bond content.
From the viewpoint of easily adjusting the reactivity of the photosensitive resin composition, liquid polybutadiene having a 1,2-vinyl bond content of 10% or less and liquid polybutadiene having a 1,2-vinyl bond content of 80% or more are mixed. It is preferable to adjust the total amount of 1,2-vinyl bonds. More preferably, liquid polybutadiene having a 1,2-vinyl bond amount of 5% or less and liquid polybutadiene having a 1,2-vinyl bond amount of 80% or more are mixed to adjust the total 1,2-vinyl bond amount. It is preferable to do.
The amount of 1,2-vinyl bonds can be determined from the peak ratio of proton NMR (magnetic resonance spectrum) of liquid polybutadiene.

  The content of the liquid diene in the photosensitive resin composition layer (b) is 10 to 40 masses when the total amount of the photosensitive resin composition is 100 mass% from the viewpoint of mechanical strength of the photosensitive resin plate for printing plates. % Is preferable, 15 to 40% by mass is more preferable, and 20 to 40% by mass is further preferable.

[Ethylenically unsaturated compound]
An ethylenically unsaturated compound refers to a compound having an unsaturated double bond capable of radical polymerization.
Examples of the ethylenically unsaturated compound include, but are not limited to, olefins such as ethylene, propylene, vinyltoluene, styrene, and divinylbenzene; acetylenes; (meth) acrylic acid and / or derivatives thereof; Haloolefins; Unsaturated nitriles such as acrylonitrile; Derivatives of acrylamide and methacrylamide; Unsaturated dicarboxylic acids such as maleic anhydride, maleic acid and fumaric acid and their derivatives; Vinyl acetates; N-vinylpyrrolidone; N-vinyl Carbazole; N-substituted maleimide compounds and the like.
In particular, (meth) acrylic acid and / or a derivative thereof is preferable from the viewpoint of abundant variety.
Examples of the derivative include, but are not limited to, for example, an alicyclic compound having a cycloalkyl group, a bicycloalkyl group, a cycloalkenyl group, a bicycloalkenyl group, and the like; a benzyl group, a phenyl group, a phenoxy group, or Aromatic compounds having naphthalene skeleton, anthracene skeleton, biphenyl skeleton, phenanthrene skeleton, fluorene skeleton, etc .; compounds having alkyl group, alkyl halide group, alkoxyalkyl group, hydroxyalkyl group, aminoalkyl group, glycidyl group, etc .; alkylene glycol , Ester compounds with polyhydric alcohols such as polyoxyalkylene glycol, polyalkylene glycol and trimethylolpropane; compounds having a polysiloxane structure such as polydimethylsiloxane and polydiethylsiloxane And the like.
Moreover, the heteroaromatic compound containing elements, such as nitrogen and sulfur, may be sufficient.

Examples of the (meth) acrylic acid and / or derivatives thereof include, but are not limited to, for example, diacrylates and dimethacrylates of alkanediols such as hexanediol and nonanediol; ethylene glycol, diethylene glycol, propylene glycol, Dipropylene glycol, polyethylene glycol, butylene glycol diacrylate and dimethacrylate; trimethylolpropane tri (meth) acrylate; dimethyloltricyclodecane di (meth) acrylate; isobornyl (meth) acrylate; phenoxypolyethylene glycol (meth) acrylate; Examples include pentaerythritol tetra (meth) acrylate.
These may be used alone or in combination of two or more.

From the viewpoint of the mechanical strength of the photosensitive resin plate for printing plates, as the ethylenically unsaturated compound, it is preferable to use at least one kind of (meth) acrylate, and to use at least one kind of bifunctional (meth) acrylate. It is more preferable.
The number average molecular weight (Mn) of the ethylenically unsaturated compound is preferably 100 or more from the viewpoint of ensuring non-volatility, preferably less than 1000 from the viewpoint of compatibility with other components such as a polymer, and 200 or more. More preferably, it is 800 or less.

  The content of the ethylenically unsaturated compound in the photosensitive resin composition layer (b) is sensitive to the printing process of the photosensitive resin composition layer (b) from the viewpoint of the printing durability of the photosensitive resin plate for printing plates. 2% to 30% by weight, more preferably 2% to 25% by weight, and more preferably 2% to 20% by weight when the total amount of the conductive resin composition is 100% by weight. More preferably.

[Photopolymerization initiator]
A photopolymerization initiator is a compound that absorbs light energy and generates radicals. A photopolymerization initiator, a hydrogen abstraction type photopolymerization initiator, a site that functions as a hydrogen abstraction type photopolymerization initiator and decay. And compounds having a site functioning as a type photopolymerization initiator in the same molecule.
As the photopolymerization initiator, various organic carbonyl compounds and particularly aromatic carbonyl compounds are suitable.
The content of the photopolymerization initiator in the photosensitive resin composition layer (b) is photosensitive in the production process of the photosensitive resin composition layer (b) from the viewpoint of printing durability of the photosensitive resin plate for printing plates. When the total amount of the resin composition is 100% by mass, it is preferably 0.1 to 10% by mass, more preferably 0.1 to 5% by mass, and 0.5 to 5% by mass. More preferably, it is set as the range.

Examples of the photopolymerization initiator include, but are not limited to, benzophenone, 4,4-bis (diethylamino) benzophenone, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid anhydride, 3, Benzophenones such as 3 ′, 4,4′-tetramethoxybenzophenone; anthraquinones such as t-butylanthraquinone and 2-ethylanthraquinone; thioxanthones such as 2,4-diethylthioxanthone, isopropylthioxanthone and 2,4-dichlorothioxanthone Michler's ketone; diethoxyacetophenone, 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2 - Ruphorino (4-thiomethylphenyl) propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) -butanone, acetophenones such as trichloroacetophenone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2 , 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, acylphosphine oxides such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; Formate; 1,7-bis acridinyl heptane; 9-phenyl acridine; azobisisobutyronitrile, diazonium compounds, azo compounds such as tetrazene compounds.
These may be used alone or in combination of two or more.

[Auxiliary additive ingredients]
The photosensitive resin composition layer (b) may contain a predetermined auxiliary additive component as necessary.
The auxiliary additive component is not particularly limited. For example, polar group-containing polymer, plasticizer other than liquid diene, thermal polymerization inhibitor other than stabilizer, antioxidant, ultraviolet absorber, dye / pigment, etc. Is mentioned.
Examples of the polar group-containing polymer include, but are not limited to, a water-soluble group having a polar group such as a hydrophilic group such as a carboxyl group, an amino group, a hydroxyl group, a phosphoric acid group, or a sulfonic acid group, or a salt thereof. Or water-dispersible copolymers. More specifically, carboxyl group-containing NBR, carboxyl group-containing SBR, a polymer of an aliphatic conjugated diene containing a carboxyl group, an emulsion polymer of an ethylenically unsaturated compound having a phosphate group or a carboxyl group, a sulfonate group Examples thereof include polyurethane containing, carboxyl group-containing butadiene latex.

From the viewpoint of obtaining high resolution in the photosensitive resin plate for printing plates, the polar group-containing polymer is preferably a carboxyl group-containing butadiene latex.
These polar group-containing polymers may be used alone or in combination of two or more.

Examples of the plasticizer other than the liquid diene include, but are not limited to, hydrocarbon oils such as naphthenic oil and paraffin oil; liquid acrylonitrile-butadiene copolymer, liquid styrene-butadiene copolymer, and the like. Conjugated diene rubber mainly composed of a liquid diene; polystyrene having a number average molecular weight of 2000 or less, sebacic acid ester, phthalic acid ester and the like. These may have a hydroxyl group or a carboxyl group at the terminal. These may be provided with a photopolymerizable reactive group such as a (meth) acryloyl group.
These plasticizers may be used alone or in combination of two or more.

As the thermal polymerization inhibitor and antioxidant, those usually used in the field of resin materials or rubber materials can be used.
Specifically, a phenol type material is mentioned.
Examples of the phenolic material include, but are not limited to, vitamin E, tetrakis- (methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate, for example. ) Methane, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methyl) Benzyl) -4-methylphenyl acrylate and the like.
These thermal polymerization inhibitors and antioxidants may be used alone or in combination of two or more.

Examples of the ultraviolet absorber include known benzophenone-based, salicylate-based, acrylonitrile-based, metal complex-based, and hindered amine-based compounds. Moreover, you may use the dye and pigment shown below as a ultraviolet absorber.
Examples of the ultraviolet absorber include, but are not limited to, 2-ethoxy-2′-ethyl oxalic acid bisanilide, 2,2′-dihydroxy-4-methoxybenzophenone, and the like.
The dye / pigment is effective as a coloring means for improving visibility.
Examples of the dye include, but are not limited to, water-soluble basic dyes, acid dyes, direct dyes, water-insoluble sulfur dyes, oil-soluble dyes, disperse dyes, and the like. . In particular, anthraquinone-based, indigoid-based, and azo-structured dyes are preferable, and azo-based oil-soluble dyes are more preferable.
Examples of the pigment include, but are not limited to, natural pigments, synthetic inorganic pigments, synthetic organic pigments, and the like. Synthetic organic pigments include azo, triphenylmethane, quinoline, and anthraquinone. And phthalocyanine series.

  The added amount of all the auxiliary additive components described above is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and 0 to 3% by mass when the total amount of the photosensitive resin composition is 100% by mass. Further preferred.

<Method for producing photosensitive resin composition layer (b)>
The photosensitive resin composition layer (b) can be produced by various methods.
For example, the raw material of the photosensitive resin composition is dissolved and mixed in an appropriate solvent, for example, a solvent such as chloroform, tetrachloroethylene, methyl ethyl ketone, or toluene, and cast into a mold to evaporate the solvent. It can be.
Moreover, it can also knead | mix with a kneader or a roll mill, without using a solvent, and can shape | mold into the board of desired thickness with an extruder, an injection molding machine, a press, etc.

<Image carrier having an image pattern>
The photosensitive resin original plate (A) for a printing plate may have an image carrier having a predetermined image pattern in addition to the support (a) and the photosensitive resin composition layer (b).
In addition, the image carrier may be separately provided in an exposure process for performing pattern exposure.
The photosensitive resin composition may have adhesiveness at room temperature depending on the composition. Therefore, if necessary, a photosensitive resin composition is applied or an extruder is used in order to improve the contact property with the image carrier superimposed on the plate carrier, and at the same time, to improve the peelability of the image carrier. It is preferable to laminate a thin film (cover sheet) on the surface of the photosensitive resin composition layer (b) formed by using an injection molding machine or by pressing. The material for the cover sheet is not particularly limited, and examples thereof include polyethylene, polypropylene, polyester, polystyrene, and the like. The film (cover sheet) is removed before the image carrier is attached.
In addition, in order to improve the contact between the photosensitive resin composition layer (b) and the image carrier having a predetermined image pattern, a solvent-soluble, thin flexible protective layer (hereinafter referred to as the film) is used instead of the film. May be simply referred to as “protective layer”) (for example, Japanese Patent Publication No. 5-13305).
This protective layer is provided as follows, for example. That is, solvent-soluble polyamide, partially saponified polyvinyl acetate, cellulose ester, etc. are dissolved in a solvent such as toluene or isopropyl alcohol to obtain a solution, and this solution is directly applied to the surface of the photosensitive resin composition layer (b). Can be coated to form a protective layer. Further, this solution is coated on a cover sheet such as a polyester film or a polypropylene film to form a protective layer, and then the cover sheet provided with the protective layer is laminated on the surface of the photosensitive resin composition layer (b). Alternatively, the protective layer may be transferred by press-bonding.
The protective layer is formed by attaching an image carrier having a predetermined image pattern on the protective layer and exposing in an image exposure step described later, and then washing out an unexposed portion of the photosensitive resin composition layer (b). At the same time, it is removed simultaneously by dissolution or the like.
Further, instead of the protective layer, an ultraviolet shielding layer containing an infrared sensitive substance may be formed, and the ultraviolet shielding layer may be used as an image carrier by performing direct drawing with an infrared laser. Also in this case, the ultraviolet shielding layer containing the infrared sensitive substance is removed at the same time when the unexposed portion is washed out after the exposure process is completed.
After forming the photosensitive resin composition layer (b) on the support (a), for example, the adhesive layer laminated on the polyester film, laminating using a roll or the like, the polyester film and the photosensitive layer The resin composition layer (b) is brought into close contact, and a photosensitive resin original plate (A) for a printing plate is formed.
The photosensitive resin original plate (A) for printing plates with better thickness accuracy can be obtained by further heat-pressing after laminating.

(Step of providing a hardened layer (B-1))
The manufacturing method of the photosensitive resin plate for printing plates of this embodiment irradiates actinic rays through the support body (a) with respect to the photosensitive resin original plate for printing plates (A) mentioned above in the process (B-1). And providing a uniform hardened layer.
Specifically, for example, exposure is performed through a support (a) made of a polyester film, the photosensitive resin composition layer (b) is photocured, and a thin uniform cured layer is provided (back exposure).
Here, the “uniform cured layer” means that the difference between the maximum thickness and the minimum thickness of the cured layer is 0.10 mm or less.

(Step of performing image exposure (B-2))
In the step (B-2), the photosensitive resin composition layer (b) is irradiated with actinic rays using an image carrier having an image pattern to perform image exposure.
For example, a negative film such as polyester is partially formed on the photosensitive resin composition layer (b), image exposure is performed on the photosensitive resin composition layer (b) through the negative film, and according to the pattern of the negative film Then, the photosensitive resin composition layer is cured (relief exposure).
Moreover, it replaces with a negative film and the thin film which can be ablated with an infrared laser may be provided, a desired image may be formed in the said thin film, and image exposure may be performed.

In the step (B-1) and the step (B-2), the actinic ray light source used for photocuring the photosensitive resin composition layer (b) or performing image exposure is limited to the following. For example, a high pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, a xenon lamp, sunlight, and the like can be given.
During exposure, the relief image is more stable with respect to the stress at the time of washing out the unexposed area, in order to make the adhesion between the support (a) and the photosensitive resin composition layer (b) stronger. In order to achieve this, it is preferable to perform the step (B-2) of performing image exposure after performing the entire surface exposure from the support (a) side as in the step (B-1).
Thereby, it becomes uniform irradiation of actinic rays, and the effect on stability of relief depth and stability of highlight formation is acquired.

In the step (B-1) and the step (B-2), the central wavelength of the actinic ray is preferably 320 nm to 380 nm from the viewpoint of increasing the efficiency of the chemical reaction. The central wavelength of the actinic ray can be measured by a commercially available optical spectrum analyzer.
The central wavelength of the actinic ray is more preferably 330 to 380 nm, and further preferably 340 to 380 nm.

In the said process (B-1) and the said process (B-2) in the manufacturing method of the photosensitive resin plate for printing plates of this embodiment, the average irradiation intensity | strength of actinic light is from a viewpoint of shortening of exposure time. It is preferably 10 mW / cm ² or more. More preferably, it is 11 mW / cm < ² > or more, More preferably, it is 12 mW / cm < ² > or more.
The irradiation intensity of actinic rays refers to the ultraviolet intensity in the UV-A region.
Here, UV-A indicates actinic rays in the wavelength region of 315 to 400 nm.
The irradiation intensity of actinic rays can be measured with a commercially available ultraviolet illuminometer, and an illuminometer that can measure the wavelength region of UV-A (315 to 400 nm) can be used. Specifically, it can be measured using an Oak UV measuring instrument UV-MO2 manufactured by Oak Seisakusho. For example, it can measure by the method described in the Example mentioned later.

(Development process (B-3))
In the step (B-3), using the developer (B), the exposed portion irradiated with actinic rays is developed, the non-exposed portion not irradiated with actinic rays is removed, and a desired image, that is, a relief is obtained. Form an image.

  The developer (B) used in the method for producing a photosensitive resin plate for a printing plate of the present embodiment is not limited to the following, but for example, chlorine such as 1,1,1-trichloroethane, tetrachloroethylene, etc. Organic solvents; esters such as heptyl acetate and 3-methoxybutyl acetate; hydrocarbons such as petroleum hydrocarbons, toluene and decalin; and those mixed with alcohols such as propanol, butanol and pentanol. Can be mentioned.

As the developer (B), an aqueous developer can also be used, and a mixture of water and alcohol, or a mixture of a surfactant or the like can also be used.
Examples of the aqueous developer include, but are not limited to, a developer containing one or more anionic, nonionic, cationic, or amphoteric surfactants.

Examples of the anionic surfactant include, but are not limited to, for example, linear alkylbenzene sulfonate having alkyl having an average carbon number of 8 to 16, and α-olefin sulfonic acid having an average carbon number of 10 to 20. Salt, dialkylsulfosuccinate having 4 to 10 carbon atoms of alkyl group or alkenyl group, sulfonate of fatty acid lower alkyl ester, alkyl sulfate having an average carbon number of 10 to 20, straight chain having an average carbon number of 10 to 20 or Examples thereof include alkyl ether sulfates having branched alkyl groups or alkenyl groups, to which an average of 0.5 to 8 mol of ethylene oxide is added, and saturated or unsaturated fatty acid salts having an average carbon number of 10 to 22.
Examples of the cationic surfactant include, but are not limited to, alkylamine salts, alkylamine ethylene oxide adducts, alkyltrimethylammonium salts, alkyldimethylbenzylammonium salts, sapamine-type quaternary ammonium salts, Or a pyridium salt etc. are mentioned.

  Examples of the nonionic surfactant include, but are not limited to, for example, polyethylene glycol type higher alcohol alkylene oxide adduct, alkylphenol alkylene oxide adduct, fatty acid alkylene oxide adduct, polyhydric alcohol fatty acid ester alkylene. Oxide adducts, higher alkylamine alkylene oxide adducts, fatty acid amide alkylene oxide adducts, fat and oil alkylene oxide adducts, polypropylene glycol alkylene oxide adducts, polyhydric alcohol glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol And fatty acid esters of sorbitan, fatty acid esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines, etc. It is.

Examples of the amphoteric surfactant include, but are not limited to, sodium laurylaminopropionate and lauryldimethylbetaine.
The concentration of the surfactant in the developing solution is not particularly limited, but is usually preferably in the range of 0.5 to 10% by mass with respect to the total amount of the cleaning solution.
In addition to the above-described surfactant, the aqueous developer may contain a cleaning aid such as a cleaning accelerator or a pH adjuster, if necessary.

  The unexposed portion may be washed out by spraying from a nozzle or by brushing with a brush. After washing out, post-exposure may be performed through a rinse cleaning / drying step.

(Drying process (B-4))
After the development processing as described above, the plate is dried.
Examples of the drying method include, but are not limited to, a drying process using heat. Specifically, drying can be performed by storing the developed plate in a dryer adjusted to 40 to 60 ° C.
The plate drying time in the drying step (B-4) is preferably 1 to 4 hours from the viewpoint of efficiency of plate making time and the volatility of the developer (B). Furthermore, it is preferable that there is a mechanism for discharging the air containing the vapor of the developing solvent in the dryer to the outside of the machine.

(Step of removing surface tack (B-5))
As above-mentioned, after the process (B-4) which performs a drying process, actinic light is irradiated, the surface tack is removed, and the photosensitive resin plate for printing plates is obtained.
This step of removing tack on the surface is also called post-exposure.

The actinic ray used in this step (B-5) is UV-C, and UV-C is an actinic ray having a wavelength region of less than 250 nm.
The central wavelength of the actinic ray can be measured with a commercially available optical spectrum analyzer, and the light source used in the step (B-5) of removing the surface tack is not limited to the following. For example, germicidal lamps, mercury lamps, metal halide lamps, LED lamps, sunlight, and the like can be used.

In the method for producing a photosensitive resin plate for a printing plate of the present embodiment, the illuminance intensity of the actinic ray in the step (B-5) can be measured by using a commercially available ultraviolet irradiator, and the UV-C wavelength region is measured. A luminometer that can be used.
Specifically, it can be measured using an Oak UV measuring instrument UV-MO2 manufactured by Oak Seisakusho.
The average irradiation intensity of the actinic ray in the step (B-5) is preferably ² to 5 mW / cm ² from the viewpoint of shortening the exposure time.
The average irradiation intensity can be measured by the method described in Examples described later.

In the step (B-5) in the method for producing a photosensitive resin plate for a printing plate of the present embodiment, the exposure distribution of active light within the exposure surface (minimum value of active light irradiation intensity / active light irradiation intensity). UV-C actinic rays are irradiated using an actinic light source having a maximum value of 60% or more.
The exposure distribution is calculated by (minimum value of irradiation intensity of active light / maximum value of irradiation intensity of active light) × 100 (%).
From the viewpoint of uniformity of tack removability on the plate surface, the exposure distribution is preferably 70% or more, and more preferably 75% or more.

When irradiating the photosensitive resin original plate for printing plate (A) with actinic rays, it is preferable that the photosensitive resin original plate for printing plates (A) is placed on a smooth substrate and irradiated with actinic rays.
The material of the smooth substrate is not limited. For example, a glass plate, a metal such as iron or stainless steel, or a plastic plate such as ABS resin or polystyrene can be used.

  When a plurality of light sources are used, the exposure distribution of actinic rays is controlled to the above numerical value range by adjusting the distance between adjacent light sources and the distance between the light source and the printing photosensitive resin original plate (A). be able to.

In addition, in the step (B-5) for removing tack on the surface, in addition to UV-C actinic ray irradiation, the actinic ray exposure distribution in the exposure surface (minimum value of actinic ray irradiation intensity / activity) It is also preferable to irradiate actinic rays UV-A having a maximum value of the irradiation intensity of light rays of 60% or more.
UV-A here means actinic rays in the wavelength region of 315 to 400 nm, and the center wavelength of the UV-A is preferably 330 to 380 nm, and more preferably 340 to 380 nm.
The UV-A light source is not limited to the following, and examples thereof include a high-pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, a xenon lamp, and sunlight.

There is no particular limitation on the timing of irradiation with UV-A, and irradiation with UV-A is performed before irradiation with UV-C. UV-C irradiation and UV-A irradiation are started simultaneously. Either UV-A irradiation may be used later. However, from the viewpoint of shortening the plate-making process and improving the photoreaction by UV-A and UV-C, irradiation of UV-C actinic rays and UV-A actinic rays is started at the same time, and irradiation is performed simultaneously. It is more preferable to do so.
The actinic ray light source used for UV-A irradiation at this time is the actinic ray light source used in the step (B-1) of providing a uniform cured layer or the step (B-2) of irradiating through an image pattern. be able to.

In step (B-5), when the photosensitive resin original plate (A) for printing plate is placed on a predetermined substrate and each step is performed, the substrate is used from the viewpoint of the stability of the chemical reaction by the active light source. The difference between the maximum value and the minimum value of the temperature in the exposure surface is preferably 10 ° C. or less.
The temperature in the exposure surface of the substrate can be measured with a thermometer.
The difference between the maximum value and the minimum value in the exposure surface of the substrate is more preferably 8 ° C. or less, and further preferably 6 ° C. or less.
The difference between the maximum value and the minimum value of the temperature in the exposure surface of the substrate is 10 by changing the material of the substrate to a material having high thermal conductivity, providing a cooling time after exposure, and cooling the substrate. It can be controlled to below ℃.

  Hereinafter, the present invention will be described with reference to specific examples and comparative examples, but the present invention is not limited thereto.

[Examples 1 to 4] [Comparative Examples 1 and 2]
In Examples 1 to 4 and Comparative Examples 1 and 2, printing plate photosensitivity was described later (production of photosensitive resin original plate for printing plate used in [Examples 1 to 4] and [Comparative Examples 1 to 2]). The photosensitive resin original plate was manufactured, and the photosensitive resin plate for printing plates was manufactured by the method described in the following (evaluation method used in the Example and the comparative example).

(Production of photosensitive resin original plate for printing plate used in [Examples 1-4] and [Comparative Examples 1-2])
A photosensitive resin composition was prepared as follows to produce a photosensitive resin original plate for a printing plate.

First, according to the material composition shown in Table 1 below, these were kneaded for 60 minutes at 140 ° C. with a kneader (Paurec Co., Ltd., FM-MW-3 type) to prepare a photosensitive resin composition.
The ratios shown in Table 1 below all indicate parts by mass.
The components in Table 1 are as follows.
Polymer A: Thermoplastic elastomer “D-KX405” which is a block copolymer of styrene-butadiene (Clayton Polymer Japan, trade name)
Liquid polybutadiene A: number average molecular weight 6000, weight average molecular weight / number average molecular weight = 1.15, 1,2-vinyl bonding amount 55%, liquid polybutadiene having a viscosity of 5.3 Pa · s at 38 ° C. liquid polybutadiene B: number average Molecular weight 3200, weight average molecular weight / number average molecular weight = 1.29, 1,2-vinyl bond content 90%, liquid polybutadiene having a viscosity of 25.0 Pa · s at 45 ° C. Liquid polybutadiene C: number average molecular weight 4600, weight average molecular weight / Number average molecular weight = 3.79, 1,2-vinyl bond content 1%, liquid polybutadiene 1,9-nonanediol diacrylate 2,2-dimethoxy-phenylacetophenone phenolic stabilizer having a viscosity at 40 ° C. of 0.70 Pa · s : 2,6-di-t-butyl-p-cresol

Next, a polyethylene terephthalate film (support) having an undercoat layer was produced as follows.
Ethylene glycol 93 g, neopentyl glycol 374 g, and phthalic acid 382 g were subjected to a condensation reaction in an air atmosphere at a reaction temperature of 180 ° C. and a reduced pressure of 1.33 × 10 ³ Pa for 6 hours, and then 4,4-diphenylene diisocyanate. 125 g was added and further reacted at 80 ° C. for 5 hours to obtain a resin.
The resin was made into a 10% aqueous solution and applied to a melt-extruded polyethylene terephthalate film. After application, the resin was biaxially stretched to obtain a polyethylene terephthalate film having an undercoat layer.
The thickness of the obtained polyethylene terephthalate film (corresponding to a support) having an undercoat layer was 100 μm, and the thickness of the undercoat layer was 0.05 μm.

Next, an ultraviolet shielding layer was manufactured.
65 parts by mass of “Asaflex 810” (trade name, manufactured by Asahi Kasei Chemicals Co., Ltd.), which is a block copolymer of styrene and 1,3-butadiene, and 35 parts by mass of carbon black as an infrared sensitive substance are kneaded in a kneader. And cut into pellets.
Thereafter, 90 parts by mass of the pellets and 10 parts by mass of 1,6-hexanediol adipate were mixed into a mixed solvent prepared with a mass ratio of ethyl acetate / butyl acetate / propylene glycol monomethyl ether acetate = 50/30/20 by ultrasonication. Was used to prepare a uniform solution having a solid content of 12% by mass.
This solution was applied onto a polyester film serving as a cover sheet having a thickness of 100 μm by using a knife coater so that the coating amount after drying was 4 to 5 g / m ^2, and dried at 80 ° C. for 1 minute. The structure which comprises the ultraviolet-ray shielding layer which can be excised by this was obtained.

Next, the photosensitive resin original plate for printing plates was manufactured using the photosensitive resin composition manufactured as mentioned above, the polyester film which has an undercoat layer, and the structure which has an ultraviolet-ray shielding layer.
The undercoat layer side of the support is matched with the photosensitive resin composition prepared as described above, and the ultraviolet shielding layer side of the structure is faced to the photosensitive resin composition. The resin composition layer is sandwiched between the polyester film having the undercoat layer and the structure having the ultraviolet shielding layer, and is heated and compression-molded so as to have a total thickness of 1.5 mm. I got the original version.
In this hot press, a pressure of 1.96 × 10 ⁷ Pa was applied at 130 ° C.
The size of one photosensitive resin original plate for a printing plate was 10 cm × 15 cm.

(Evaluation methods used in Examples and Comparative Examples)
<(1) Evaluation of UV-C active light source>
TUV75W (trade name: Philips Co., Ltd.) connected to a ballast was arranged in a line, and a post-exposure apparatus having an ultraviolet irradiation range of 900 mm × 1200 mm was produced. Moreover, the photosensitive resin original plate for printing plates produced as mentioned above was installed in the predetermined board | substrate. A stainless steel plate was used as the substrate.
The distance between each lamp of TUV75W (trade name: Philips) and the distance between each lamp and the substrate on which the photosensitive resin original plate for printing plate is placed are adjusted as shown in Table 2, and the ultraviolet ray measuring device UV- With MO2 (product name, manufactured by Oak Manufacturing Co., Ltd.), 18 points were measured at equal intervals so that the light intensity was uniform, and the average irradiation intensity (average value when measured over 10 points with the exposure range evenly distributed) was measured. ) And exposure distribution (minimum value of irradiation intensity of actinic rays / maximum value of irradiation intensity of actinic rays).
The exposure distribution was expressed as% (minimum value of active light irradiation intensity / maximum value of active light irradiation intensity) × 100.
The temperature of the substrate is measured by bringing a contact-type thermometer into contact with the substrate, measuring the temperature at 18 points, and calculating the average temperature of the substrate and the difference between the highest value and the lowest value in the exposure surface of the substrate (maximum value − The lowest value was calculated.
In the post-exposure device, TL60W10R (product name: Philips) was arranged in a row on top of TUV75W (product name: Philips), and UV-A irradiation was also possible. The irradiation intensity of UV-A at this time was 5.0 mw / cm ^{2 as} measured by the ultraviolet ray measuring device UV-MO2.
Also in TL60W10R (trade name: Philips), the exposure distribution of UV-A was calculated as described above.

<(2) Image exposure, tack removal>
In the photosensitive resin original plate for a printing plate produced as described above, only the polyester film was peeled off so that the ultraviolet shielding layer was transferred to the photosensitive resin composition layer, The drum was loaded on a “classic” (Esko-Graphics, trade name, 1064 nm YAG laser).
The laser power is set to 20 W, the drum rotation speed is set to 1600 rpm, laser drawing is performed on the ultraviolet shielding layer on the photosensitive resin original plate for the printing plate, a part of the ultraviolet shielding layer is cut out, and a test pattern having a solid of 5 × 5 cm is formed. Laser drawing was performed.
First, 25 photosensitive resin original plates for printing plates on which a pattern is drawn are arranged at regular intervals in an exposure machine having a predetermined exposure surface (900 mm × 1200 mm), and 100 mJ / cm from the side of the polyethylene terephthalate film having an undercoat layer. ² back exposure was performed.
As an active light irradiation light source, an ultraviolet fluorescent lamp TL80W-10R (product name: Philips) was used.
Moreover, the irradiation intensity | strength of the actinic light was measured using the ultraviolet-ray measuring device UV-MO2 (product name, product made by Oak Manufacturing).
Subsequently, the photosensitive resin original plate for printing plate was inverted and irradiated with 8000 mJ / cm ² of ultraviolet rays from the ultraviolet shielding layer side to perform image exposure.
Using a Quickline 912 developing machine (trade name, manufactured by Asahi Kasei Co., Ltd.) using Sorbit (made by McDermid, trade name, mixed organic solvent of hydrocarbons 60 wt%, aliphatic alcohol 40 wt%, boiling point 155 to 205 ° C.) as a developer. Then, development was performed at a liquid temperature of 30 ° C.
Next, the drying process for 2 hours was performed at 60 degreeC.
Thereafter, under the conditions shown in Table 2, the entire plate surface after drying was exposed to 2000 mJ / cm ² as UV-C to obtain a photosensitive resin plate for a printing plate. The amount of post-exposure by UV-C was calculated from the illuminance measured using the UV-25 filter of the “UV-MO2” machine. Moreover, UV-A measured the amount of post-exposure with “UV-MO2” and performed exposure at 1000 mJ / cm ² .
In Examples 1 to 3 and Comparative Example 1, UV-C and UV-A started and ended actinic ray irradiation simultaneously. In Example 4 and Comparative Example 2, UV-A irradiation was started. After finishing, UV-C irradiation was performed.

<(3) Evaluation of tack removal uniformity>
Tack removability evaluation was performed about 25 printing plates obtained on each condition.
The surface tack of the photosensitive resin original plate for printing plates was measured using a “PICMA tack tester” (manufactured by Toyo Seiki Co., Ltd.).
At 20 ° C., the solid part of the photosensitive resin original plate for printing plate was brought into contact with the aluminum ring having a radius of 50 mm and a width of 13 mm, and a load of 0.5 kg was applied to the aluminum ring and left for 4 seconds. The aluminum ring was pulled up at a constant speed of 30 mm, and the resistance force when the aluminum ring was separated from the sample was read with a push-pull gauge.
The larger this value, the greater the tack.
Evaluation was made according to the following criteria.
The case where 20 or more of 25 sheets are 100 N / m or less.
When 25 or more of 15 sheets are 100 N / m or less
When 25 sheets, 100 N / m or less is less than 15 sheets, ×
It was.
25 sheets of photosensitive resin plate for printing plate obtained after the step of removing tack on the surface was fixed to a plate cylinder of a flexographic printing press having a width of 40 cm and a circumference of 60 cm using double-sided tape, and XS-716 (DIC stock) Company, trade name) was used to print on polyethylene film.
As a result, when the tackiness evaluation was ◎, all printed plates could be printed without adhesion of foreign matters such as paper dust.
Even in the case of ○, foreign matter such as paper dust was small, and visual discrimination was difficult, and printing was possible sufficiently.
On the other hand, in the doubled printing plate which became x, about 5 sheets of visible paper dust were generated, and there was a problem in printing the solid part.

  In Examples 1 to 4, it was possible to stably produce a printing plate having uniform tack removability on the plate surface and excellent solid quality with excellent production efficiency.

  The method for producing a photosensitive resin plate for a printing plate of the present invention has industrial applicability as a method for producing a flexographic printing plate.

Claims (3)

A method for producing a photosensitive resin plate for a printing plate using a photosensitive resin original plate (A) for a printing plate having a support (a) and a photosensitive resin composition layer (b),
Step (B-1) of irradiating the photosensitive resin original plate for printing plate (A) with actinic rays through the support (a) to provide a uniform cured layer;
Irradiating the photosensitive resin composition layer (b) with an actinic ray through an image pattern to perform image exposure (B-2);
Using the developer (B) to develop the exposed portion irradiated with actinic rays and removing the non-exposed portion not irradiated with actinic rays (B-3);
A step (B-4) of performing a drying treatment;
Irradiating actinic rays to remove surface tack (B-5);
In order,
In the step (B-5) of removing the tack on the surface, the exposure distribution of the actinic ray in the UV-C exposure surface (minimum value of irradiation intensity of actinic light / maximum value of irradiation intensity of actinic light) is 60 Irradiating UV-C actinic rays using an active light source that is at least%,
A method for producing a photosensitive resin plate for a printing plate. In the step (B-5) of removing the tack on the surface, in addition to the irradiation with the actinic ray of UV-C, the exposure distribution of the actinic ray in the exposure surface (minimum value of the actinic ray irradiation intensity / actinic ray Using an active light source UV-A having a maximum irradiation intensity of 60% or more, UV-C irradiation and UV-A irradiation are simultaneously performed.
The manufacturing method of the photosensitive resin plate for printing plates of Claim 1. The photosensitive resin composition layer (b) is
The manufacturing method of the photosensitive resin plate for printing plates of Claim 1 or 2 containing a thermoplastic elastomer, an ethylenically unsaturated compound, and a photoinitiator.