JP2022115173A - Photosensitive resin printing plate original plate and method for producing printing plate using the same - Google Patents

Abstract

To provide a photosensitive resin printing plate original plate which suppresses coagulation of a development waste liquid and can afford a printing plate having low plate surface stickiness under a high humidity atmosphere, that is, to provide a photosensitive resin composition and a photosensitive resin printing plate original plate which can reduce adhesion of paper powder during printing.SOLUTION: A photosensitive resin printing plate original plate comprises at least a substrate and a photosensitive resin layer, where the photosensitive resin layer comprises: (A) 30 to 70 mass% of a polyamide resin having a basic nitrogen(s) or a polyether(s) in the main chain; (B) 10 to 60 mass% of a compound having an ethylenic double bond(s); (C) 0.5 to 10 mass% of a photopolymerization initiator; and (D) 0.1 to 5.0 mass% of a fluorine compound having a polar group(s) and/or a silicone compound having a polar group(s).SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a photosensitive resin printing plate precursor and a method for producing a printing plate using the same.

As a method of forming a relief from a photosensitive resin printing plate precursor, the photosensitive resin layer is irradiated with ultraviolet light through an image mask or original film to selectively cure the image areas, and the uncured areas are treated with a developing solution. is generally used.

Compositions used for photosensitive resin printing plate precursors and photosensitive resin layers have hitherto been known for letterpress printing containing at least a water-soluble polymer compound, a photopolymerizable unsaturated compound, and a photopolymerization initiator as essential components. wherein the water-soluble polymer compound comprises (A) an ω-amino acid or its lactam, (B) a hydrophilic diamine, (C) a hydrophobic diamine, (D) an amino-modified silicone compound, and (E) a photosensitive resin composition for letterpress printing characterized by being a copolycondensate obtained by a polycondensation reaction of a dicarboxylic acid (see, for example, Patent Document 1).

JP 2016-71044 A

A photosensitive resin printing plate precursor having a photosensitive resin layer using a polyamide resin having such a hydrophilic group can be easily dissolved or dispersed in a developer in the preparation of a printing plate, and the durability of the printing plate is excellent. Therefore, it is preferably used.

By the way, as a printing method using a printing plate obtained from a photosensitive resin printing plate precursor, ink is supplied to the relief surface formed from the photosensitive resin layer, and the ink on the relief surface is transferred to a printing medium such as paper. The letterpress printing method is common. In the letterpress printing method, the relief of the printing plate and the material to be printed come into contact with each other through the ink. Therefore, if foreign matter such as paper dust derived from the material to be printed adheres to the surface of the relief, printing defects are induced. In order to suppress the generation of static electricity during printing, it is effective to maintain humidity, for example, a relative humidity of 50 RH% or more, but in particular, polyamide resins having hydrophilic groups such as basic groups are hydrophilic. The adhesiveness of the relief surface was high depending on the group, and there was a tendency that foreign substances such as paper dust originating from the printed material tended to adhere during printing under high humidity.

Further, a photosensitive resin printing plate precursor using a polyamide resin having a hydrophilic group such as a basic group can be developed using a developer containing water, but the polyamide resin dissolved or dispersed in the developer is However, there is a problem in the treatment of developer waste, because aggregates are likely to occur depending on conditions such as the temperature of the developer and the hardness of the water used in the developer.

In view of the above problems, an object of the present invention is to provide a photosensitive resin printing plate precursor capable of suppressing aggregation of developer waste and obtaining a printing plate with low plate surface tackiness in a high humidity environment.

In order to solve the above problems, the present invention mainly has the following configurations.
A photosensitive resin printing plate precursor having at least a support and a photosensitive resin layer, wherein the photosensitive resin layer contains (A) 30 to 70% by mass of a polyamide resin having basic nitrogen and/or polyether in the main chain. , (B) 10 to 40% by mass of a compound having an ethylenic double bond, (C) 0.5 to 10% by mass of a photopolymerization initiator, and (D) a fluorine compound having a polar group and/or a silicone having a polar group A photosensitive resin printing plate precursor containing 0.1 to 5.0% by mass of a compound.

With the photosensitive resin printing plate precursor of the present invention, it is possible to obtain a printing plate that suppresses aggregation of developer waste and has low plate surface tackiness in a high-humidity environment.

Embodiments of the present invention will be described below.

The photosensitive resin printing plate precursor of the present invention has at least a support and a photosensitive resin layer. The support has a function of holding the photosensitive resin layer. The photosensitive resin layer includes (A) a polyamide resin having a basic nitrogen and / or polyether in the main chain, (B) a compound having an ethylenic double bond, (C) a photopolymerization initiator and (D ) refers to a layer containing a fluorine compound having a polar group and/or a silicone compound having a polar group, and may have two or more photosensitive resin layers.

Examples of the support include plastic sheets such as polyester, synthetic rubber sheets such as styrene-butadiene rubber, and metal plates such as steel, stainless steel, and aluminum. The thickness of the support is preferably in the range of 100 to 350 μm from the viewpoint of handleability and flexibility.

The support is preferably treated for easy adhesion, so that the adhesion to the relief and floor layer can be improved. Examples of the adhesive treatment method include mechanical treatment such as sandblasting, physical treatment such as corona discharge, and chemical treatment such as coating. Among these, from the viewpoint of adhesion, it is preferable to provide an easy-adhesion layer by coating.

In the photosensitive resin printing plate precursor of the present invention, the photosensitive resin layer comprises at least (A) a polyamide resin having basic nitrogen and/or polyether in the main chain, (B) a compound having an ethylenic double bond, ( C) a photopolymerization initiator and (D) a fluorine compound having a polar group and/or a silicone compound having a polar group. When the photosensitive resin layer is imagewise irradiated with light such as ultraviolet rays, free radicals are generated from the (C) photopolymerization initiator in the photosensitive resin layer in the exposed areas. The generated free radicals can induce radical polymerization between (B) compounds having an ethylenic double bond and form a relief for obtaining a desired printed image due to the crosslinked structure. Furthermore, by containing (D) a fluorine compound having a polar group and/or a silicone compound having a polar group, the tackiness of the relief surface of the printing plate obtained from the photosensitive resin printing plate precursor in a high humidity environment is reduced. , adhesion of foreign matter such as paper dust derived from the printing medium can be suppressed. In addition, by including the above-mentioned (D) compound, it is possible to suppress aggregation of the developer waste liquid.

The photosensitive resin layer in the present invention contains (A) a polyamide resin having basic nitrogen and/or polyether in its main chain. Inclusion of basic nitrogen and/or hydrophilic groups of the polyether allows removal of uncured portions by aqueous developers during the development step.

Examples of the basic nitrogen in the polyamide resin having a basic nitrogen in the main chain include nitrogen of a piperazine group and an amino group. You may use 2 or more types of these. The polyamide resin having a basic nitrogen in its main chain preferably has a piperazine group or an amino group such as an N,N-dialkylamino group in its main chain, and preferably has a piperazine group in its main chain. Polyamide resins having these basic nitrogens in the main chain promote the reaction of unsaturated epoxy compounds such as glycidyl methacrylate with amino groups and carboxyl groups at the ends of polyamide resins, active hydrogens of amide bonds, etc., so that polyamide An ethylenic double bond can be easily introduced into the resin using an unsaturated epoxy compound. The ethylenic double bond in the polyamide resin is radically polymerized with the ethylenic double bond in the polyamide resin or (B) the compound having an ethylenic double bond by exposure, so that a fine relief can be formed. , the image reproducibility can be improved.

Polyamide resin having a basic nitrogen in the main chain, for example, a monomer having a basic nitrogen, optionally together with other diamines, dicarboxylic acids, ω-amino acids, lactams, etc., condensation polymerization or polyaddition reaction can be obtained by As a monomer having a basic nitrogen, a monomer having a piperazine group or an N,N-dialkylamino group is preferable, and a monomer having a piperazine group is more preferable.

Monomers having a basic nitrogen include, for example, N,N'-bis(aminomethyl)-piperazine, N,N'-bis(β-aminoethyl)-piperazine, N,N'-bis(γ- aminobenzyl)-piperazine, N-(β-aminoethyl)piperazine, N-(β-aminopropyl)piperazine, N-(ω-aminohexyl)piperazine, N-(β-aminoethyl)-2,5-dimethyl Piperazine, N,N-bis(β-aminoethyl)-benzylamine, N,N-bis(γ-aminopropyl)-benzylamine, N,N'-dimethyl-N,N'-bis(γ-aminopropyl )-ethylenediamine, N,N'-dimethyl-N,N'-bis(γ-aminopropyl)-tetramethylenediamine; N,N'-bis(carboxymethyl)-piperazine, N,N'- Bis(carboxymethyl)-methylpiperazine, N,N'-bis(carboxymethyl)-2,6-dimethylpiperazine, N,N'-bis(β-carboxyethyl)-piperazine, N,N-bis(carboxymethyl )-methylamine, N,N-bis(β-carboxyethyl)-ethylamine, N,N-bis(β-carboxyethyl)-methylamine, N,N-di(β-carboxyethyl)-isopropylamine, N , N'-dimethyl-N,N'-bis-(carboxymethyl)-ethylenediamine, N,N'-dimethyl-N,N'-bis-(β-carboxyethyl)-ethylenediamine or other dicarboxylic acids or lower thereof Alkyl esters and acid halides, N-(aminomethyl)-N'-(carboxymethyl)-piperazine, N-(aminomethyl)-N'-(β-carboxyethyl)-piperazine, N-(β-aminoethyl )-N′-(β-carboxyethyl)-piperazine, N-carboxymethylpiperazine, N-(β-carboxyethyl)piperazine, N-(γ-carboxyhexyl)piperazine, N-(ω-carboxyhexyl)piperazine, N-(aminomethyl)-N-(carboxymethyl)-methylamine, N-(β-aminoethyl)-N-(β-carboxyethyl)-methylamine, N-(aminomethyl)-N-(β- ω-amino acids such as carboxyethyl)-isopropylamine, N,N'-dimethyl-N-(aminomethyl)-N'-(carboxymethyl)-ethylenediamine, and the like.

Examples of the polyether of the polyamide resin having polyether in the main chain include polyethylene oxide and polypropylene oxide. You may use 2 or more types of these. Among these, polyethylene oxide is preferable, and the number average molecular weight of the polyethylene oxide portion is preferably 200 or more and 6,000 or less. By setting the number average molecular weight of the polyethylene oxide to 200 or more, the solubility in the water-containing developer can be further improved, and the aggregation of the waste developer can be further suppressed. On the other hand, by setting the number average molecular weight of the polyethylene oxide portion to 6,000 or less, compatibility with other components in the photosensitive resin layer can be improved. The polyamide resin having these polyethers in the main chain imparts flexibility to the relief obtained by photocuring the photosensitive resin layer, and can be easily adjusted to a hardness suitable for various printing methods.

Polyamide resins having a polyether in the main chain are, for example, α, ω-diaminopolyoxyethylene obtained by adding acrylonitrile to both ends of polyethylene glycol or the like and hydrogen-reducing this, or polyethylene glycol at both ends A monomer having a polyether such as a compound to which a dicarboxylic acid such as succinic anhydride is added is subjected to condensation polymerization or polyaddition reaction, optionally together with other diamines, dicarboxylic acids, ω-amino acids, lactams, etc. can be obtained by

Polyamide resin contains all the components constituting the polyamide resin, that is, the sum of aminocarboxylic acid units (including lactam as a raw material), dicarboxylic acid units and diamine structural units, monomers and polyethers having basic nitrogen It is preferable to use a total of 20 to 90 mol% of monomers having By using 20 mol % or more of the above-mentioned monomer, the solubility in a water-containing developer can be further improved, and aggregation of developer waste can be further suppressed. It is more preferable to use 30 mol % or more of the above monomers. On the other hand, by using 90 mol % or less of the above-mentioned monomer, it is possible to suppress water absorption during storage of the printing plate and maintain the thickness accuracy of the printing plate at a high level. Here, the sum of the monomers having a basic nitrogen and the monomers having a polyether means that when only either the monomers having a basic nitrogen or the monomers having a polyether are used, Either means the sum when both the basic nitrogen-bearing monomer and the polyether-bearing monomer are used.

(A) Other monomers constituting the polyamide resin having a basic nitrogen and/or polyether in the main chain include, for example, ω-aminocaproic acid, ω-aminoenanthic acid, ω-aminocaprylic acid, ω- aminocarboxylic acids such as aminobergonic acid, ω-aminocapric acid, 11-aminoundecanoic acid and 12-aminododecanoic acid; lactams such as caprolactam, enantholactam, capryllactam and laurolactam; diamines such as hexamethylenediamine and dodecamethylenediamine , terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, sodium 5-sulfoisophthalate aromatic dicarboxylic acids such as; 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, dicyclohexyl-4,4'-dicarboxylic acid and other aliphatic dicarboxylic acids; succinic acid, oxalic acid, adipic acid, sebacic acid , and aliphatic dicarboxylic acids such as decanedicarboxylic acid. You may use 2 or more types of these.

(A) The weight average molecular weight of the polyamide resin having basic nitrogen and/or polyether in the main chain is preferably 10,000 or more and 200,000 or less. Here, the weight average molecular weight can be determined by GPC measurement. More specifically, using a Wyatt Technology gel permeation chromatograph-multi-angle light scattering photometer, the weight average molecular weight can be measured under the conditions of column temperature: 40 ° C. and flow rate: 0.7 mL / min. . Polyethylene oxide and polyethylene glycol are used as standard samples.

The content of (A) the polyamide resin having basic nitrogen and/or polyether in the main chain in the photosensitive resin layer is 30 to 70% by mass based on the total solid content of the photosensitive resin layer. Here, (A) the content of the polyamide resin having a basic nitrogen and/or polyether in the main chain is either a polyamide resin having a basic nitrogen in the main chain or a polyamide resin having a polyether in the main chain When it contains only the basic nitrogen in the main chain, it means the content, and when it contains both the polyamide resin having the basic nitrogen in the main chain and the polyamide resin having the polyether in the main chain, it means the total content. (A) By containing 30% by mass or more of the polyamide resin having basic nitrogen and/or polyether in the main chain, the moldability of the photosensitive resin layer can be improved. (A) The content of the polyamide resin having basic nitrogen and/or polyether in the main chain is preferably 35% by mass or more. On the other hand, by containing 70% by mass or less of (A) a polyamide resin having basic nitrogen and/or polyether in the main chain, uncured portions can be easily removed with a developer containing water. (A) The content of the polyamide resin having basic nitrogen and/or polyether in the main chain is preferably 65% by mass or less. The content of (A) the polyamide resin having a basic nitrogen and/or polyether in the main chain in the photosensitive resin layer is obtained by separating the polyamide resin by GPC from the solution in which the photosensitive resin layer is dissolved, It can be quantified by combining pyrolysis GC-MS analysis, ¹ H-NMR analysis, ¹³ C-NMR analysis under inert gas, and LC-MS analysis for alkaline hydrolyzate of polyamide resin.

(B) A compound having an ethylenic double bond refers to a compound having an ethylenic double bond and having a molecular weight of less than 10,000. (B) The compound having an ethylenic double bond preferably has a molecular weight of 2,000 or less.

(B) Compounds having an ethylenic double bond include, for example, (meth)acrylates described in WO 2017/038970, glycerol di(meth)acrylate, and (meth)acryl of propylene glycol diglycidyl ether acid adducts, tetrahydrofurfuryl (meth)acrylate and the like. You may contain 2 or more types of these. Here, (meth)acrylate is a generic term for acrylate and methacrylate, and (meth)acrylic acid is a generic term for acrylic acid and methacrylic acid.

The content of (B) the compound having an ethylenic double bond in the photosensitive resin layer is 10 to 60% by mass. By containing 10% by mass or more of (B) a compound having an ethylenic double bond, a fine relief can be formed and image reproducibility can be improved. (B) The content of the compound having an ethylenic double bond is preferably 15% by mass or more. On the other hand, by containing 60% by mass or less of (B) a compound having an ethylenic double bond, a photosensitive resin layer can be easily formed. The content of (B) the compound having an ethylenic double bond in the photosensitive resin layer was determined by sampling low molecular weight components by GPC, ¹ H-NMR analysis, ¹³ C-NMR analysis, LC-MS, and GC. -Can be quantified by combining MS and the like.

As the photopolymerization initiator (C), those having a function of generating radicals by self-decomposition or hydrogen abstraction upon absorption of light are preferably used. Examples include benzoin alkyl ethers, benzophenones, anthraquinones, benzyls, acetophenones, diacetyls and the like. You may contain 2 or more types of these.

The content of (C) the photopolymerization initiator in the photosensitive resin layer is 0.5 to 10% by mass. By containing 0.5% by mass or more of the photopolymerization initiator (C), a fine relief can be formed and image reproducibility can be improved. (C) The content of the photopolymerization initiator is preferably 1% by mass or more. On the other hand, when the photopolymerization initiator (C) is contained in an amount of 10% by mass or less, fine concave portions such as cutout characters can be formed, and image reproducibility can be improved. (C) The content of the photopolymerization initiator is preferably 8% by mass or less. The content of the photopolymerization initiator (C) in the photosensitive resin layer was measured by collecting low-molecular-weight components by GPC, ¹ H-NMR analysis, ¹³ C-NMR analysis, LC-MS, GC-MS, and the like. By combining, it is possible to quantify.

(D) In the fluorine compound having a polar group and/or the silicone compound having a polar group, the polar group refers to a group containing an oxygen atom and/or a nitrogen atom with high electronegativity, such as a sulfonic acid group. , a quaternary ammonium group, a phosphate group, a carboxyl group, a hydroxyl group, an amino group, a phenol group, and the like. By having these groups, (A) compatibility with the polyamide resin having a basic nitrogen and / or polyether in the main chain is improved, (D) a fluorine compound having a polar group and / or having a polar group It is possible to suppress bleeding out of the silicone compound from the photosensitive resin layer and obtain a printing plate having a relief surface with low tackiness in a high-humidity environment. In addition, by containing (D) a fluorine compound having a polar group and/or a silicone compound having a polar group, aggregation of developer waste liquid can be suppressed, and a printing plate having a relief surface with low tackiness in a high-humidity environment can be obtained. Obtainable.

Examples of the fluorine compound having a polar group include a polar group such as a sulfonic acid group, a quaternary ammonium group, a phosphoric acid group, a carboxyl group, and a hydroxyl group, and a fluorine-containing group such as a perfluoroalkyl group and a perfluoroalkenyl group. compound. Examples of such compounds include "Ftergent" (registered trademark) 100 (Neos Co., Ltd.) as a fluorine compound having a sulfonic acid group, and "Ftergent" 300 (Neos Co., Ltd.) as a fluorine compound having a quaternary ammonium group. Co., Ltd.), FPE-50 (AGC Seimi Chemical Co., Ltd.) as a fluorine compound having a phosphate group, and "Futhergent" 251 (Neos Co., Ltd.) as a fluorine compound having a hydroxyl group.

Betaine is also preferred as a fluorine compound having a polar group. Betaine, for example, has a positive charge such as a polar quaternary ammonium group and a negative charge such as a carboxylic acid or sulfonic acid at positions not adjacent to each other in the same molecule, and dissociates into atoms having a positive charge. It is a compound (inner salt) in which the hydrogen atoms are not bonded and the molecule as a whole has no electric charge. Point. Aggregation resulting from deposition of salt of an ionic substance in the waste developer can be suppressed.

Among fluorine compounds having a polar group, examples of betaine include "Futergent" 400SW (Neos), S-231 (AGC Seimi Chemical Co., Ltd.) and the like.

(D) The silicone compound having a polar group includes, for example, a part of the side chain of dimethylsilicone oil, a methyl group at both ends or one end, and a polar group such as an amino group, a hydroxyl group, a carboxyl group, and a phenol group. Examples include compounds substituted with a group containing.

Among these, those having a hydroxyl group as a polar group include, for example, X-22-4039, X-22-4015, X-22-4952, X-22-4272, X-22-170BX, X-22-170DX , KF-6000, KF-6001, KF-6002, KF-6003, KF-6123, X-22-176F (manufactured by Shin-Etsu Chemical Co., Ltd.), "Silaplane" FM-4411, "Silaplane" FM- 4421, "Silaplane" FM-4425, "Silaplane" FM-0411, "Silaplane" FM-0421, "Silaplane" FM-DA11, "Silaplane" FM-DA21, "Silaplane" FM-DA26 ( manufactured by JNC Co., Ltd.) and the like. Those having an amino group include KF-868, KF-865, KF-864 (manufactured by Shin-Etsu Chemical Co., Ltd.), "Silaplane" FM-3311, "Silaplane" FM-3321, and "Silaplane" FM -3325, (manufactured by JNC Corporation) and the like. Those having a carboxyl group include X-22-3701 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The content of (D) the fluorine compound having a polar group and/or the silicone compound having a polar group in the photosensitive resin layer is 0.1 to 5.0% by mass based on the total solid content of the photosensitive resin layer. Here, (D) the content of the fluorine compound having a polar group and/or the content of the silicone compound having a polar group refers to the content of either the fluorine compound having a polar group or the silicone compound having a polar group, if only The content means the total content when both the fluorine compound having a polar group and the silicone compound having a polar group are included. By containing 0.1% by mass or more of such a compound, it is possible to reduce the tackiness of the relief surface in a high-humidity environment and obtain a printing plate to which foreign substances such as paper dust are less likely to adhere. In addition, aggregation of developer waste can be suppressed. The content of such compounds is more preferably 0.3% by mass or more. On the other hand, by setting the content of (D) the fluorine compound having a polar group and/or the silicone compound having a polar group to 5.0% by mass or less, bleeding out from the photosensitive resin layer is suppressed, and paper dust, etc. It is possible to obtain a printing plate to which foreign matter is less likely to adhere. The content of such compounds is more preferably 2.0% by mass or less. The content of (D) the fluorine compound having a polar group and/or the silicone compound having a polar group in the photosensitive resin layer was determined by collecting a low molecular weight component by GPC and ^{performing 1} H-NMR analysis. It can be quantified by a combination of C-NMR analysis, LC-MS, GC-MS and the like.

In the photosensitive resin layer, together with the above components, if necessary, (A) a polymer other than a polyamide resin having a basic nitrogen and / or polyether in the main chain, a compatibility aid, a polymerization inhibitor, a dye, It may contain pigments, surfactants, antifoaming agents, UV absorbers, fragrances, and the like.

By including a compatibility aid in the photosensitive resin layer, the compatibility of the components constituting the photosensitive resin layer is enhanced, and the bleeding out of low-molecular-weight components is further suppressed, while improving the flexibility of the photosensitive resin layer. can be made Examples of compatible aids include polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol and derivatives thereof. The content of the compatibility aid in the photosensitive resin layer is preferably 30% by mass or less.

Thermal stability can be improved by containing a polymerization inhibitor in the photosensitive resin layer. Examples of polymerization inhibitors include phenols, hydroquinones, catechols, and hydroxylamine derivatives. You may contain 1 or more types of these. The content of the polymerization inhibitor in the photosensitive resin layer is preferably 0.001 to 5 mass %.

The photosensitive resin printing plate precursor of the present invention may have a cover film or a heat-sensitive mask layer on the photosensitive resin layer, if necessary, in addition to the aforementioned support and photosensitive resin layer.

By providing the cover film on the photosensitive resin layer, the surface of the photosensitive resin layer can be protected and the adhesion of foreign matter and the like can be suppressed. The photosensitive resin layer and the cover film may be in direct contact, or one or more anti-tack layers may be provided between the photosensitive resin layer and the cover film.

Examples of cover films include plastic sheets made of polyester, polyethylene, polypropylene and the like. The thickness of the cover film is preferably 10 to 150 μm from the viewpoint of handleability and flexibility. Also, the surface of the cover film may be roughened to improve adhesion with the original film. Examples of roughening methods include sandblasting, chemical etching, and coating with a coating agent containing matting particles.

Also, the photosensitive resin printing plate precursor of the present invention is subjected to laser irradiation based on image data controlled by a digital device, forming an image mask on the spot from the mask layer element, and exposing and developing a so-called CTP platemaking method. , the photosensitive resin printing plate precursor may further have a heat-sensitive mask layer. Preferably, the heat-sensitive mask layer practically blocks ultraviolet light, absorbs infrared laser light during writing, and is partially or wholly sublimated or ablated instantaneously by the heat. As a result, there is a difference in optical density between the laser-irradiated portion and the non-irradiated portion, and the same function as a conventional original film can be achieved. When the photosensitive resin printing plate precursor has a heat-sensitive mask layer, it may have an adhesive strength adjusting layer between the photosensitive resin layer and the heat-sensitive mask layer, and a peeling aid layer may be provided between the heat-sensitive mask layer and the cover film. may have.

Examples of the heat-sensitive mask layer, the adhesive strength adjusting layer, and the release assisting layer include those described in International Publication No. 2017/038970.

Next, the method for producing a photosensitive resin printing plate precursor of the present invention will be described by taking as an example a case where a photosensitive resin layer and a cover film are provided on a support.

For example, components (A) to (D) and, if necessary, other additives are heated and dissolved in a solvent to obtain a photosensitive resin composition solution. Examples of solvents include water/alcohol mixed solvents.

A photosensitive resin composition solution is cast on a support having an easily adhesive layer, if necessary, and dried to form a photosensitive resin layer. Next, a photosensitive resin printing plate precursor can be obtained by adhering a cover film coated with an anti-adhesion layer, if necessary, onto the photosensitive resin layer.

A method for producing a printing plate using the photosensitive resin printing plate precursor of the present invention will be described. It is preferable to have an exposure step of partially photocuring the photosensitive resin layer of the photosensitive resin printing plate precursor and a developing step of removing the uncured portion of the photosensitive resin layer with a developer containing water.

In the exposure step, a negative or positive original image film is adhered onto the photosensitive resin layer from which the cover film has been peeled off if it has a cover film, and ultraviolet rays having a wavelength of 300 to 400 nm are irradiated to expose the exposed area of the photosensitive resin layer. is preferably photocured. When a heat-sensitive mask layer is provided, it is preferable to form a negative or positive image on the heat-sensitive mask layer and irradiate ultraviolet rays through this. Examples of the exposure light source include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, UV-LED lamps, and the like.

In the developing step, it is preferable to remove the photosensitive resin layer in the unexposed areas with a liquid containing water. Examples of the developing device include a spray type developing device and a brush type washing machine.

Furthermore, if necessary, a post-exposure step of irradiating with ultraviolet rays may be provided after development. In the post-exposure step, the reaction of the unreacted (B) ethylenic double bond-containing compound can make the relief stronger.

The photosensitive resin printing plate precursor and the printing plate of the present invention can be used for letterpress printing and flexographic printing using a label printing rotary press or an intermittent rotary press. Among these, it can be preferably used for letterpress printing.

EXAMPLES The present invention will be specifically illustrated by examples below, but the present invention is not limited to these. The evaluation methods in Examples and Comparative Examples are shown below.

(1) Bleed-out "GATSBY" (registered trademark) oil blotting paper film type (manufactured by Mandom) was cut into a size of 2 cm x 2 cm, and the weight was measured. A weighed "GATSBY" blotting paper film type (manufactured by Mandom) was attached to the surface of the photosensitive resin printing plate precursor obtained in each example and comparative example, and after absorbing the bleed-out component, the same was applied. The weight was measured at The amount of bleed-out was calculated from the change in weight before and after absorption of the bleed-out component (weight after absorption - weight before absorption). A bleed-out amount of less than 0.1 g was considered acceptable.

(2) Plate surface tackiness From the 20 cm × 20 cm photosensitive resin printing plate precursor obtained in each example and comparative example, only the polyester film of the cover film was peeled off, and a CDI2120 laser drawing machine (manufactured by Esko Graphics Co., Ltd.) was used. was used to draw a relief surface adhesion evaluation chart (having a solid image of 15×15 cm) at a laser energy of 4.0 J/cm ² . Exposure was performed for 9 minutes (main exposure) using a chemical lamp FL20SBL-360, 20 watts (manufactured by Mitsubishi Electric Osram Co., Ltd.) through the mask layer after drawing. After that, it is developed with a brush type developing device using water at a liquid temperature of 25° C. as a developer, dried at 60° C. for 10 minutes, and further using a chemical lamp FL20SBL-360 20 watts (manufactured by Mitsubishi Electric Osram Co., Ltd.). Post-exposure was performed under the same conditions as the main exposure to obtain a printing plate for plate surface tackiness evaluation.

After the obtained printing plate for plate surface adhesion evaluation was stored for one day in an environment of 25° C. and 75 RH%, a 5 cm×15 cm OK top coat paper (manufactured by Oji Paper Co., Ltd.) was applied to the relief surface using a roller. pressed and adhered. After that, it was fixed to the 5 cm side of the digital force gauge AD-4932A-50N (manufactured by A&E Co., Ltd.) using double-sided tape, and the OK top coat paper was peeled off from the relief at a speed of 1 cm / sec. Measure the maximum stress and use it as the plate adhesion force. A plate surface adhesive force of less than 0.2 N was considered acceptable.

(3) Image reproducibility From the 10 cm × 10 cm CTP photosensitive printing plate precursor obtained in each example and comparative example, only the polyester film of the cover film was peeled off, and a laser drawing machine CDI2120 (manufactured by Esko Graphics Co., Ltd.) was used. ) was used to draw an image reproducibility evaluation chart (having 175-line 2% halftone dots formed in an area of 1 cm×1 cm) at a laser energy of 4.0 J/cm ² . Exposure was performed for 9 minutes (main exposure) using a chemical lamp FL20SBL-360, 20 watts (manufactured by Mitsubishi Electric Osram Co., Ltd.) through the mask layer after drawing. After that, it is developed with a brush-type developing device using water at a developer temperature of 25°C as a developer for 2 minutes, dried at 60°C for 10 minutes, and further chemical lamp FL20SBL-360 20 watts (manufactured by Mitsubishi Electric Osram Co., Ltd.). was used to post-expose under the same conditions as the main exposure to obtain a printing plate for image reproducibility evaluation.

175-line 2% halftone dots formed on the obtained printing plate for evaluation of image reproducibility were observed using a 20-fold magnifying glass and evaluated according to the following criteria.
5: No chipping 4: Chipping is observed in halftone dots in the outermost area 3: Chipping is detected in the outermost area and the area in the second row from the outermost circumference 2: Internal area including the third row from the outermost circumference 1: Chipping is observed in 20% or more of the entire halftone dot area.

(4) Aggregation of developer waste The photosensitive resin layer is left standing at 40° C. in water with a concentration of 5% by weight aqueous solution, and the presence or absence of aggregation is visually observed every 24 hours for up to 168 hours. It was measured. A time of 48 hours or longer until aggregation was observed was considered acceptable.

Next, methods for producing the materials used in each example and comparative example will be described.

<Synthesis of polyamide resin>
Synthesis Example 1: Synthesis of polyamide resin 1 Acrylonitrile was added to both ends of polyethylene glycol having a number average molecular weight of 600, and hydrogen reduction was performed to obtain an equimolar salt of α,ω-diaminopolyoxyethylene and adipic acid 80. 20 mol % of an equimolar salt of hexamethylenediamine and adipic acid was melt-polymerized to obtain a water-soluble polyamide resin 1 having polyethylene oxide in the main chain. In addition, using Wyatt Technology's gel permeation chromatograph-multi-angle light scattering photometer, column temperature: 40 ° C., flow rate: 0.7 mL / min, weight using polyethylene oxide and polyethylene glycol as standard samples The average molecular weight was measured to be 80,000.

Synthesis Example 2: Synthesis of polyamide resin 2 Acrylonitrile was added to both ends of polyethylene glycol having a number average molecular weight of 600, and hydrogen reduction was performed to obtain an equimolar salt of α,ω-diaminopolyoxyethylene and adipic acid 40. 100 parts by mass of a mixture of 20 mol% of ε-caprolactam, 40 mol% of an equimolar salt of N-(2-aminoethyl)piperazine and adipic acid, and 100 parts by mass of water were placed in a stainless steel autoclave, and the air inside was was replaced with nitrogen gas, heated at 180° C. for 1 hour, and then water was removed to obtain a water-soluble polyamide resin 2 having a polyethylene oxide skeleton and basic nitrogen in the main chain. When the weight average molecular weight was measured in the same manner as in Synthesis Example 1, it was 70,000.

<Preparation of Support Having Easily Adhesive Layer>
100 parts by mass of a polyester adhesive (“Vylon” (registered trademark) 30SS (copolyester, manufactured by Toyobo Co., Ltd.) on a polyester film “Lumirror” (registered trademark) S10 (manufactured by Toray Industries, Inc.) having a thickness of 188 μm and "Coronate" (registered trademark) L (polyvalent isocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd.) 3 parts by mass solution) was applied using a bar coater so that the thickness after drying was 20 μm, It was dried at 90° C. for 10 minutes to form a support having an easy-adhesion layer.

<Preparation of thermal mask layer element>
Partially saponified polyvinyl acetate "Gosenol" (registered trademark) KL-05 manufactured by Mitsubishi Chemical Corporation (degree of polymerization: about 500, degree of saponification: 78 to 82 mol%) and polyamide resin 2, 10 parts by mass each, water 5 parts by mass of carbon black "MA100" manufactured by Mitsubishi Chemical Corporation was dispersed in a solution dissolved in 100 parts by mass of a mixed solvent of methanol = 50:50 (mass ratio), and a coating solution for a thermal mask layer was prepared. Obtained. The heat-sensitive mask layer coating solution thus obtained was applied to a 100 μm-thick “Lumirror” (registered trademark) S10 (polyester film, manufactured by Toray Industries, Inc.) and dried at 120° C. for 20 seconds to form a heat-sensitive mask layer. / A thermal mask element consisting of a cover film was obtained. The optical density (orthochromatic filter, transmission mode) of this thermal mask element was 2.5.

The following compounds were used as compounds having an ethylenic double bond.
B-1: glycidyl methacrylate B-2: 2-methacryloyloxyethyl-2-hydroxyethyl-phthalic acid B-3: acrylic acid adduct of propylene glycol diglycidyl ether B-4: tetrahydrofurfuryl methacrylate fluorine-containing organic The following products were used as compounds.
"Phtergent" 100: manufactured by NEOS Co., Ltd., containing sulfonic acid group "Phtergent" 300: manufactured by NEOS Co., Ltd., containing quaternary ammonium salt "Phtergent" 400SW: manufactured by NEOS Co., Ltd., betaine-containing "Ftergent""730LM: manufactured by Neos Co., Ltd., no polar group The following products were used as silicone compounds.
KF6001: manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl group-containing KF-96L-1cs: manufactured by Shin-Etsu Chemical Co., Ltd., no polar group.

[Example 1]
<Preparation of photosensitive resin layer>
A mixed solvent of polyamide resin 1 and polyamide resin 2 and ethanol/water = 30/70 (mass ratio) was added in an amount shown in Table 1 in a three-necked flask equipped with a stirring spatula and a cooling tube, and 90 It was dissolved by heating at ℃ for 2 hours. After cooling the resulting mixture to 70° C., other components listed in Table 1 were added and stirred for 30 minutes to obtain a solution for a photosensitive resin layer. The solution for the photosensitive resin layer obtained as described above is cast on the easy-adhesion layer side of the support having the easy-adhesion layer, and dried at 60° C. for 2.5 hours to improve the photosensitivity of the printing plate precursor. A resin layer was formed. At this time, the plate thickness after drying (support + photosensitive resin layer) was adjusted to 0.95 mm.

A mixed solvent of water/ethanol=50/50 (mass ratio) is applied onto the photosensitive resin layer thus obtained, and the heat-sensitive mask layer side of the above-mentioned heat-sensitive mask layer element is pressure-bonded to the surface, followed by exposure. A flexible resin printing plate precursor 1 was obtained.

Table 1 shows the results of evaluation of the photosensitive resin printing plate precursor 1 by the method described above.

[Examples 2 to 12]
Photosensitive resin printing plate precursors 2 to 12 were obtained in the same manner as in Example 1, except that the composition of the photosensitive resin layer was changed as shown in Tables 1 and 2. Tables 1 and 2 show the results of evaluation by the method described above.

[Comparative Examples 1 to 5]
Photosensitive resin printing plate precursors 13 to 17 were obtained in the same manner as in Example 1 except that the composition of the photosensitive resin layer was changed as shown in Table 3, and evaluated by the method described above. However, Comparative Examples 2 to 5 had a large amount of bleeding out and were not suitable for evaluation. Table 3 shows the evaluation results.

Claims (6)

A photosensitive resin printing plate precursor having at least a support and a photosensitive resin layer, wherein the photosensitive resin layer contains (A) 30 to 70% by mass of a polyamide resin having basic nitrogen and/or polyether in the main chain. , (B) 10 to 60% by mass of a compound having an ethylenic double bond, (C) 0.5 to 10% by mass of a photopolymerization initiator, and (D) a fluorine compound having a polar group and/or a silicone having a polar group A photosensitive resin printing plate precursor containing 0.1 to 5.0% by mass of a compound. The photosensitive resin printing plate precursor according to claim 1, wherein (A) the polyamide resin having a basic nitrogen in its main chain has a piperazine group. 2. The photosensitive resin printing plate precursor according to claim 1, wherein (A) the polyamide resin having a polyether in the main chain contains polyethylene oxide. The photosensitive resin according to any one of claims 1 to 3, wherein the photosensitive resin layer contains 0.3 to 2.0% by mass of (D) a fluorine compound having a polar group and/or a silicone compound having a polar group. Original printing plate. The photosensitive resin printing plate precursor according to any one of claims 1 to 4, wherein (D) the fluorine compound having a polar group and/or the silicone compound having a polar group has a hydroxyl group, a quaternary ammonium group and/or a carboxyl group. . An exposure step of partially photocuring the photosensitive resin layer of the photosensitive resin printing plate precursor according to any one of claims 1 to 5, and removing an uncured portion of the photosensitive resin layer with a developer containing water. A method for producing a printing plate, comprising a development step.