Flexographic printing plate master and method for manufacturing flexographic printing plates

Abstract

To provide a flexographic printing plate master that offers excellent image reproduction and is resistant to swelling of the relief when used with any of the following inks: solvent inks, water-based inks, UV-curing inks, and EB-curing inks. A flexographic printing plate master having a resin layer on a substrate containing a total of 40% by mass or more of silicone polymer and / or silicone rubber, and a photoreaction initiator.

Description

[Technical Field]

[0001] This invention relates to a flexographic printing plate master, a method for manufacturing a flexographic printing plate, and a method for manufacturing printed materials. [Background technology]

[0002] Flexographic printing, leveraging its flexibility, is widely used in paper packaging, labels, flexible packaging, and electronics applications. Flexographic printing is a printing method in which ink is applied to the raised relief of a flexographic printing plate, and then the relief is pressed onto the substrate, transferring the ink from the relief to the substrate.

[0003] One method for forming the relief on a flexographic printing plate used in flexographic printing is to selectively photo-cure the image portion by irradiating the photosensitive resin layer of the photosensitive flexographic printing plate master with ultraviolet light through an image mask or original film, and then removing the uncured portion with a developer. By such a method, fine images can be formed with high precision.

[0004] As a material for the relief of a photosensitive flexographic printing plate, an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with high rubber elasticity is preferably used. For example, a photosensitive resin composition for solvent-developable or heat-developable flexographic printing plates (see, for example, Patent Document 1) has been proposed, characterized by containing (a) a block copolymer including a polymer block mainly composed of a conjugated diene and a polymer block mainly composed of a vinyl aromatic hydrocarbon, (b) a photopolymerizable monomer, (c) a photopolymerization initiator, and (d) an organosilicon compound. Alternatively, a method for manufacturing a printing plate using a photopolymerizable element that includes a composition layer comprising a composition layer that is partially liquefiable, comprising at least one elastomer block copolymer including a mixture of a polystyrene-polybutadiene-polystyrene tri-block copolymer and a polystyrene-polybutadiene di-block copolymer, an ethylene-unsaturated compound, and a photoinitiator (see, for example, Patent Document 2). Furthermore, a photosensitive resin plate (see, for example, Patent Document 3) has been proposed as a water-developable flexographic plate that can be developed with water, using a photosensitive resin composition comprising a resin (A) containing an ionic functional group, a photopolymerization initiator (B), a photopolymerizable monomer (C), and a fluorine-containing compound (D) having an ionic functional group that can form a counterion with resin (A). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2007 / 116941 [Patent Document 2] Japanese Patent Publication No. 2010-107981 [Patent Document 3] International Publication No. 2018 / 88336 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In addition to solvent-based inks that use organic solvents as solvents, water-based inks that primarily use water as a solvent and active energy ray-cured inks that harden with active energy rays such as ultraviolet (UV) or electron beams (EB) have recently come into use in flexographic printing, from the perspective of reducing environmental impact. From the perspective of suppressing image swelling during printing and maintaining stable print quality, flexographic printing plates are required to be resistant to swelling with these various inks. However, the flexographic printing plates described in Patent Documents 1 and 2 had the problem of being prone to swelling with solvent-based inks, UV-cured inks, and EB-cured inks. Furthermore, the flexographic printing plate described in Patent Document 3 had the problem of being prone to swelling with water-based inks.

[0007] Therefore, the present invention aims to provide a flexographic printing plate master that can be obtained that has excellent image reproducibility and is less prone to swelling of the relief when used with any of the following inks: solvent inks, water-based inks, UV-curing inks, and EB-curing inks. [Means for solving the problem]

[0008] To solve the above problems, the present invention mainly has the following configuration. (1) A flexographic printing plate master having a resin layer on a substrate containing a total of 40% by mass or more of silicone polymer and / or silicone rubber and a photoreaction initiator. (2) The flexographic printing plate according to (1), wherein the silicone polymer has a functional group selected from a hydrosilyl group, a silanol group, an alkenyl group having 2 to 8 carbon atoms, a (meth)acryloyl group, an epoxy group, a glycidyl group, an alcoholic hydroxyl group, and a phenolic hydroxyl group. (3) The flexographic printing plate according to (1) or (2), wherein the silicone polymer has two or more functional groups selected from silanol groups and alkenyl groups having 2 to 8 carbon atoms in its polymer chain. (4) A flexographic printing plate according to any one of (1) to (3), further containing a crosslinking agent in the resin layer. (5) The flexographic printing plate precursor according to (4), wherein the crosslinking agent has a hydrosilyl group or a mercapto group. (6) The flexographic printing plate precursor according to any one of (1) to (5), wherein the photoinitiator contains a metal compound. (7) The flexographic printing plate precursor according to (6), wherein the metal compound contains a platinum compound. (8) The flexographic printing plate precursor according to (7), wherein the platinum compound has absorption at a wavelength of 365 nm. (9) The flexographic printing plate precursor according to any one of (1) to (8), wherein the photoinitiator contains a photo radical generator. (10) The flexographic printing plate precursor according to any one of (1) to (9), wherein the resin layer further contains a reinforcing material. (11) A method for manufacturing a flexographic printing plate, comprising an exposure step of irradiating light to the flexographic printing plate precursor according to any one of (1) to (10) to partially photocrosslink the resin layer, and a development step of removing the uncrosslinked portion of the resin layer in this order. (12) A method for manufacturing a printed matter, comprising a step of attaching ink to the relief of the flexographic printing plate obtained by the manufacturing method according to (11), and a step of transferring the ink to a printing object.

Advantages of the Invention

[0009] The flexographic printing plate precursor of the present invention is excellent in image reproducibility, and a flexographic printing plate with a relief that is difficult to swell can be obtained for any of solvent inks, water-based inks, UV-curable inks, and EB-curable inks.

Embodiments for Carrying Out the Invention

[0010] The flexographic printing plate master of the present invention (hereinafter sometimes abbreviated as "printing plate master") is a printing plate master having a resin layer on a substrate, wherein the resin layer contains a total of 40% by mass or more of silicone polymer and / or silicone rubber and a photoreaction initiator. The resin layer may contain two or more types of silicone polymer or silicone rubber, or it may contain both silicone polymer and silicone rubber. The substrate has the function of supporting the resin layer and the relief in the flexographic printing plate master or flexographic printing plate (hereinafter sometimes abbreviated as "printing plate"). The resin layer of the flexographic printing plate master is a layer for forming the relief, and by forming the unevenness by photolithography, it becomes the relief of the flexographic printing plate. It is preferable to have a floor layer between the substrate and the resin layer, which can improve the reproducibility of fine lines and independent points, and further improve image reproducibility.

[0011] In this invention, "silicone" refers to a general term for organopolysiloxanes having repeating siloxane bonds (-Si-O-Si-) in the main chain and organic groups in the side chains. Among these, "silicone polymer" refers to a chain-like polydiorganosiloxane consisting of repeating bifunctional siloxane units (D units). Furthermore, "silicone rubber" refers to a material obtained by crosslinking a silicone polymer. When a silicone polymer is contained in the resin layer of a printing plate master, the silicone polymer is crosslinked during the exposure process to become silicone rubber. Because silicone rubber has high rubber elasticity, it can improve the flexibility of the relief of a flexographic printing plate.

[0012] The printing plate original of the present invention can be made into a printing plate having a relief containing 40% by mass or more of a silicone polymer and / or silicone rubber in the resin layer. Since silicone rubber is excellent in chemical resistance and solvent resistance, it is difficult to swell in solvents generally contained in solvent inks, or acrylic monomers generally contained in UV-curable inks and EB-curable inks. Also, silicone rubber is difficult to swell in water. Therefore, a relief containing 40% by mass or more of silicone rubber is difficult to swell in any of solvent inks, aqueous inks, UV-curable inks, and EB-curable inks. On the other hand, a relief with a silicone rubber content of less than 40% by mass has a relatively higher content of other components, and since these are likely to swell in any of solvent inks, aqueous inks, UV-curable inks, and EB-curable inks, the relief is likely to swell. The content of silicone rubber in the relief is more preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. For this reason, the total content of the silicone polymer and / or silicone rubber in the resin layer of the printing plate original of the present invention is more preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. Here, the total content of the silicone polymer and / or silicone rubber in the resin layer means the content when only one kind of silicone polymer or silicone rubber is contained, and the total content when both the silicone polymer and silicone rubber are contained or two or more kinds of either are contained.

[0013] From the viewpoint of further improving image reproducibility, the printing plate master of the present invention preferably contains a silicone polymer as an essential component in the resin layer. The content of the silicone polymer in the resin layer is preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more, from the viewpoint of suppressing swelling with any of the solvent inks, aqueous inks, UV-curing inks, and EB-curing inks. On the other hand, from the viewpoint of promoting photocuring, the content of the silicone polymer in the resin layer is preferably 99.5% by mass or less, and more preferably 99% by mass or less. Furthermore, from the viewpoint of suppressing the flow of the resin layer before photocrosslinking and maintaining its shape, and from the viewpoint of increasing the mechanical strength of the resin layer after photocrosslinking and hysteresis loss during repeated deformation, the content of the silicone polymer in the resin layer is more preferably 95% by mass or less, and even more preferably 90% by mass or less. The resin layer may contain both silicone polymer and silicone rubber. The preferred total content when both silicone polymer and silicone rubber are included is as described above.

[0014] The printing plate master of the present invention contains a photoinitiator in the resin layer. The photoinitiator absorbs light to generate active species, which can promote the crosslinking reaction of the silicone polymer in the resin layer. As a result, the crosslinking density of the resulting relief is increased, making it less susceptible to swelling with any of the following inks: solvent inks, water-based inks, UV-curing inks, and EB-curing inks. Furthermore, by performing a photocrosslinking reaction using short-wavelength light, a flexographic printing plate with excellent image reproduction can be obtained.

[0015] The printing plate master of the present invention preferably contains a crosslinking agent in the resin layer, and more preferably contains a silicone polymer and a crosslinking agent in the resin layer. By containing a silicone polymer and a crosslinking agent, the crosslinking agent crosslinks the silicone polymer during the exposure process, forming silicone rubber. Therefore, the resin layer is given photosensitivity, and a relief pattern can be easily formed by the exposure and development processes described later.

[0016] The silicone polymer preferably has functional groups selected from hydrosilyl groups, silanol groups, alkenyl groups having 2 to 8 carbon atoms, (meth)acryloyl groups, epoxy groups, glycidyl groups, alcoholic hydroxyl groups, and phenolic hydroxyl groups. Because these functional groups are highly reactive, they promote crosslinking between silicone polymers having these functional groups and with crosslinking agents described later, thereby further suppressing swelling of the relief in relation to the ink. Furthermore, since the silicone polymer having these functional groups can be photocrosslinked by photoinitiators described later, the resin layer can be given photosensitivity, and the relief can be easily patterned by the exposure and development processes described later. The polymer chain of the silicone polymer may contain two or more of these functional groups. Here, "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups.

[0017] Among these functional groups, silanol groups or C2-C8 alkenyl groups are preferred. Examples of C2-C8 alkenyl groups include vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptenyl groups, and octenyl groups. From the viewpoint of crosslinking, vinyl groups are preferred.

[0018] It is more preferable that the silicone polymer has two or more functional groups selected from silanol groups and C2-C8 alkenyl groups in its polymer chain. The silanol groups in the polymer chain react with silanol groups and alkoxysilyl groups of other silicone polymers, and with silanol groups and alkoxysilyl groups of crosslinking agents. The C2-C8 alkenyl groups in the polymer chain react with C2-C8 alkenyl groups and hydrosilyl groups of other silicone polymers, and with hydrosilyl groups and mercapto groups of crosslinking agents. Therefore, by having two or more of these functional groups in a single polymer chain, the crosslinking density of the resulting relief can be increased, and swelling of the relief in relation to the ink can be further suppressed.

[0019] Examples of silicone polymers having two or more silanol groups in their polymer chains include DMS-S27, DMS-S32, DMS-S33, DMS-S35, DMS-S42, DMS-S45, DMS-S51, and PDS-0338 (all manufactured by Gelest, INC.). Two or more of these may be used.

[0020] Among silicone polymers having two or more vinyl groups in the polymer chain, examples of silicone polymers having vinyl groups at both ends of the polymer chain include DMS-V22, DMS-V25, DMS-V31, DMS-V33, DMS-V35, DMS-V41, DMS-V42, DMS-V46, DMS-V51, DMS-V52, DMS-Vm31, DMS-Vm35, and DMS Examples include the V25R, DMS-V35R, PDV-0325, PDV-0331, PDV-0341, PDV-0346, PDV-0525, PDV-0535, PDV-0541, PDV-1631, PDV-1635, PDV-1641, PDV-2331, PDV-2335, FMV-4042, and EDV-2022 (all manufactured by Gelest, INC.). Furthermore, examples of silicone polymers having two or more vinyl groups in the side chains of the polymer chain include VDT-123, VDT-127, VDT-131, VDT-163, VDT-431, VDT-731, VDT-954, VDT-5053, VDV-0131, VGM-021, VGP-061, VGF-991, VDH-422 (all manufactured by Gelest, INC.) and TF-26, TF-36, TF-40 (all manufactured by Dow Toray Industries, Inc.). Two or more of these may be used.

[0021] The weight-average molecular weight (Mw) of the silicone polymer is preferably 10,000 or more, and more preferably 20,000 or more, from the viewpoint of further suppressing swelling of the relief in relation to various inks. On the other hand, from the viewpoint of improving the crosslinkability of the silicone polymer and adhesion to the relief substrate, the Mw of the silicone polymer is preferably 300,000 or less, and more preferably 120,000 or less, in the case of a silicone polymer having the aforementioned functional groups at both ends of the polymer chain. Furthermore, in the case of a silicone polymer having the aforementioned functional groups in the side chains of the polymer chain, the Mw is preferably 1,000,000 or less, and more preferably 800,000 or less. Here, the Mw of the silicone polymer can be measured by gel permeation chromatography (GPC) using polystyrene as a standard. When two or more types of silicone polymers are included, the Mw refers to the Mw of the two or more silicone polymers as a whole.

[0022] When the printing plate master of the present invention contains silicone rubber in the resin layer, examples of silicone rubber include those obtained by crosslinking the aforementioned silicone polymer, or silicone rubber powder. Examples of silicone rubber powder include KMP-402 (average particle size 30 μm), KMP-597 (average particle size 5 μm), and KMP-598 (average particle size 13 μm) (all manufactured by Shin-Etsu Chemical Co., Ltd.). Two or more of these may be used.

[0023] Photoinitiators absorb light to generate active species, thereby promoting the crosslinking reaction of silicone polymers. Examples of active species include metals and / or metal compounds that act as catalysts for the crosslinking reaction, acids, bases, and radicals. Examples of photoinitiators include metal compounds, photoacid generators, and photoradical generators.

[0024] It is preferable that the metal compound generates a catalyst by absorbing light. Examples of metals to be included in the metal compound include platinum, palladium, titanium, zirconium, tin, bismuth, ruthenium, rhodium, osmium, and iridium. Examples of the metal compound include chlorides of the aforementioned metals, complexes with β-diketone compounds, complexes with β-ketoester compounds, complexes with β-diester compounds, and complexes with cyclic diene compounds. Two or more of these may be included.

[0025] Among these, platinum compounds are preferred, as they promote crosslinking of the silicone polymer, increase the crosslinking density of the relief, and further suppress swelling of the relief in relation to the ink. In particular, when the silicone polymer and / or crosslinking agent have alkenyl groups or hydrosilyl groups with 2 to 8 carbon atoms, hydrosilylation can be efficiently promoted, further increasing the crosslinking density of the relief and further suppressing swelling of the relief in relation to the ink.

[0026] Among these, platinum compounds having absorption at a wavelength of 365 nm are preferred. By having absorption at a wavelength of 365 nm, they are activated by light emitted from a light source containing light at a wavelength of 365 nm and exhibit catalytic activity that promotes the addition reaction between a component having an alkenyl group with 2 to 8 carbon atoms and a component having a hydrosilyl group. That is, when the resin layer contains a silicone polymer having an alkenyl group or hydrosilyl group with 2 to 8 carbon atoms and a crosslinking agent described later, by including a platinum compound having absorption at a wavelength of 365 nm, the resin layer is given photosensitivity to light at a wavelength of 365 nm, and a relief pattern can be formed by the exposure and development processes described later. Examples of platinum compounds having absorption at a wavelength of 365 nm include β-diketone platinum complexes and platinum complexes having a cyclic diene compound as a ligand.

[0027] Examples of β-diketone platinum complexes include trimethyl(acetylacetonate) platinum complex, trimethyl(2,4-pentanedionate) platinum complex, trimethyl(3,5-heptanedionate) platinum complex, trimethyl(methylacetoacetate) platinum complex, bis(2,4-pentanedionate) platinum complex, bis(2,4-hexanedionate) platinum complex, bis(2,4-heptanedionate) platinum complex, bis(3,5-heptanedionate) platinum complex, bis(1-phenyl-1,3-butanedionate) platinum complex, and bis(1,3-diphenyl-1,3-propanedionate) platinum complex. Two or more of these may be used.

[0028] Examples of platinum complexes having cyclic diene compounds as ligands include (1,5-cyclooctadienyl)dimethylplatinum complex, (1,5-cyclooctadienyl)diphenylplatinum complex, (1,5-cyclooctadienyl)dipropylplatinum complex, (2,5-norboradienene)dimethylplatinum complex, (2,5-norboradienene)diphenylplatinum complex, (cyclopentadienyl)dimethylplatinum complex, (methylcyclopentadienyl)diethylplatinum complex, (trimethylsilylcyclopentadienyl)diphenylplatinum complex, and (methylcycloocta-1,5 Examples include (-dienyl)diethylplatinum complex, (cyclopentadienyl)trimethylplatinum complex, (cyclopentadienyl)ethyldimethylplatinum complex, (cyclopentadienyl)acetyldimethylplatinum complex, (methylcyclopentadienyl)trimethylplatinum complex, (methylcyclopentadienyl)trihexylplatinum complex, (trimethylsilylcyclopentadienyl)trimethylplatinum complex, (dimethylphenylsilylcyclopentadienyl)triphenylplatinum complex, and (cyclopentadienyl)dimethyltrimethylsilylmethylplatinum complex. Two or more of these may be used.

[0029] Among these, bis(2,4-heptanedionato)platinum complex or (methylcyclopentadienyl)trimethylplatinum complex are even more preferred from the viewpoint of activity to light at a wavelength of 365 nm.

[0030] When a metal compound is contained in the resin layer, from the viewpoint of further enhancing the catalytic activity of the crosslinking reaction and further suppressing swelling of the relief with respect to various inks, the content of the metal compound in the resin layer is preferably 1 ppm or more, and more preferably 10 ppm or more, as metal, relative to the total mass of the silicone polymer and silicone rubber. On the other hand, from the viewpoint of improving the storage stability of the printing plate, the content of the metal compound in the resin layer is preferably 5,000 ppm or less, and more preferably 2,000 ppm or less, as metal, relative to the total mass of the silicone polymer and silicone rubber.

[0031] Preferably, the photoacid generator has absorption at a wavelength of 365 nm. By having absorption at a wavelength of 365 nm, it is activated by light emitted from a light source containing light at a wavelength of 365 nm and exhibits catalytic activity that promotes the condensation reaction between the component having a silanol group and the component having an alkoxysilyl group. That is, when the resin layer contains a silicone polymer having a silanol group and a crosslinking agent described later, by including a photoacid generator that has absorption at a wavelength of 365 nm, the resin layer is given photosensitivity to light at a wavelength of 365 nm, and a relief pattern can be formed by the exposure and development processes described later.

[0032] Examples of photoacid generators having absorption at a wavelength of 365 nm include onium salt-type ionic photoacid generators and nonionic photoacid generators. Among these, nonionic photoacid generators are preferred. Preferred nonionic photoacid generators include oxime sulfonate compounds and imido sulfonate compounds. Oxime sulfonate compounds and imido sulfonate compounds generate sulfo groups with high acid dissociation constants (pKa) upon exposure to light, thereby increasing the sensitivity of printing plates.

[0033] Examples of oxime sulfonate compounds include “Irgacure®” PAG-103 (benzeneacetonitrile, 2-methyl-α-[[(propylsulfonyl)oxy]imino]-3(2H)-thienylidene), PAG-121 (benzeneacetonitrile, 2-methyl-α-[[(4-methylphenyl)oxy]imino]-3(2H)-thienylidene), PAG-108 (benzeneacetonitrile, 2-methyl-α-[[(n-octyl)oxy]imino]-3(2H)-thienylidene), PAG-203 (all manufactured by BASF Japan Ltd.), and PAI-101 ((Z)-4-methoxy-N-(tosiloxy)benzimidoylcyanide, manufactured by Midori Chemical Co., Ltd.). Two or more of these may be used.

[0034] Examples of imidosulfonate compounds include N-hydroxynaphthalimide triflate, "ADEKA ARCULUS®" SP-606 (4-butyl-N-hydroxynaphthalimide triflate, manufactured by ADEKA Corporation), NA-101 (N-hydroxynaphthalimide-p-toluenesulfonate), and NA-106 (N-hydroxynaphthalimide camphor sulfonate, all manufactured by Midori Chemical Co., Ltd.). Two or more of these may be used.

[0035] When a photoacid generator is included in the resin layer, from the viewpoint of further enhancing the catalytic activity of the condensation reaction and further suppressing swelling of the relief with respect to various inks, the content of the photoacid generator in the resin layer is preferably 0.1 parts by mass or more, and more preferably 0.2 parts by mass or more, per 100 parts by mass of the total of the silicone polymer and silicone rubber. On the other hand, from the viewpoint of improving the storage stability of the printing plate, the content of the photoacid generator in the resin layer is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total of the silicone polymer and silicone rubber.

[0036] Preferably, the photoradical generator has absorption at a wavelength of 365 nm. By having absorption at a wavelength of 365 nm, it generates radicals when exposed to light from a light source containing light at a wavelength of 365 nm, promoting ene / thiol reactions between components having alkenyl groups with 2 to 8 carbon atoms and components having mercapto groups, as well as radical polymerization reactions between components having alkenyl groups with 2 to 8 carbon atoms and between components having (meth)acryloyl groups. In other words, when the resin layer contains alkenyl groups with 2 to 8 carbon atoms in the silicone polymer or crosslinking agent, or contains a silicone polymer having alkenyl groups with 2 to 8 carbon atoms and a crosslinking agent having mercapto groups, or contains (meth)acryloyl groups in the silicone polymer or crosslinking agent, including a photoradical generator that absorbs at a wavelength of 365 nm imparts photosensitivity to light at a wavelength of 365 nm to the resin layer, allowing for the formation of a relief pattern through the exposure and development processes described later.

[0037] Examples of photoradical generators having absorption at a wavelength of 365 nm include 2,2-diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by BASF Japan Ltd., “Irgacure®” 651), 1-hydroxycyclohexylphenyl-ketone (manufactured by BASF Japan Ltd., “Irgacure®” 184), 2-hydroxy-2-methyl-1-phenylpropan-1-one (manufactured by BASF Japan Ltd., “Irgacure®” 1173), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one (manufactured by BASF Japan Ltd., “Irgacure®” 127), and phenylglyoxy Examples include ric acid methyl ester (manufactured by BASF Japan Ltd., “Irgacure®” MBF), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by BASF Japan Ltd., “Irgacure®” 907), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone (manufactured by BASF Japan Ltd., “Irgacure®” 369), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (manufactured by BASF Japan Ltd., “Irgacure®” 819), and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (manufactured by BASF Japan Ltd., “Irgacure®” TPO). Two or more of these may be used. Among these, 2,2-diethoxyacetophenone, "Irgacure®" 1173, "Irgacure®" 819, and "Irgacure®" TPO are preferred from the viewpoint of compatibility and solubility with the silicone polymer in the resin layer.

[0038] When a photoradical generator is included in the resin layer, from the viewpoint of promoting the ene / thiol reaction and radical polymerization reaction and further suppressing swelling of the relief with respect to various inks, the content of the photoradical generator in the resin layer is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more, per 100 parts by mass of the total of the silicone polymer and silicone rubber. On the other hand, from the viewpoint of improving the storage stability of the printing plate, the content of the photoradical generator in the resin layer is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total of the silicone polymer and silicone rubber.

[0039] The crosslinking agent preferably has a functional group selected from hydrosilyl groups, silanol groups, C2-C8 alkenyl groups, (meth)acryloyl groups, epoxy groups, glycidyl groups, mercapto groups, alcoholic hydroxyl groups, phenolic hydroxyl groups, and alkoxysilyl groups, and more preferably has two or more of these functional groups in the molecule. Because these functional groups are highly reactive, they promote crosslinking with the aforementioned silicone polymer and other crosslinking agents, and can further suppress swelling of the relief in relation to the ink. Two or more of these functional groups may be present.

[0040] When the resin layer contains a silicone polymer having hydrosilyl groups, the crosslinking agent is preferably one having C2 to C8 alkenyl groups. Having C2 to C8 alkenyl groups in the crosslinking agent further promotes crosslinking and further suppresses swelling of the relief with respect to the ink. Examples of crosslinking agents having C2 to C8 alkenyl groups include vinylmethylsiloxane-dimethylsiloxane copolymers such as VDT-123, VDT-127, VDT-131, VDT-431, VDT-731, VDT-5053, VDV-0131, and VDH-422 (all manufactured by Gelest Inc.).

[0041] When the resin layer contains a silicone polymer having a silanol group, the crosslinking agent preferably has a silanol group or an alkoxysilyl group, and more preferably has an alkoxysilyl group. Having these functional groups further promotes crosslinking and further suppresses swelling of the relief relative to the ink. Examples of crosslinking agents having an alkoxysilyl group include silicate oligomers such as ethyl silicate 40, ethyl silicate 48, and methyl silicate 51 (all manufactured by Colcoat Co., Ltd.).

[0042] When a silicone polymer having C2-C8 alkenyl groups is contained in the resin layer, the crosslinking agent is preferably a C2-C8 alkenyl group, a hydrosilyl group, or a mercapto group. Here, as the silicone polymer having C2-C8 alkenyl groups, various polymers are commercially available, such as those having vinyl groups as exemplified earlier, allowing for a wide range of compositional designs.

[0043] When the crosslinking agent has alkenyl groups having 2 to 8 carbon atoms, it can further promote crosslinking with the alkenyl groups having 2 to 8 carbon atoms in the silicone polymer, thereby further suppressing swelling of the relief in relation to the ink. Examples of crosslinking agents having alkenyl groups having 2 to 8 carbon atoms include the crosslinking agents mentioned above.

[0044] When a crosslinking agent has a hydrosilyl group, the presence of hydrogen directly bonded to Si further promotes crosslinking and suppresses swelling of the relief in relation to the ink. Examples of crosslinking agents having a hydrosilyl group include "SILASTIC®" RD-1 Rubber Additive (manufactured by Dow Toray Industries, Inc.), HMS-151, and HMS-301 (all manufactured by Gelest, Inc.), which are methylhydrogensiloxane-dimethylsiloxane copolymers, and polymethylhydrogensiloxanes such as HMS-993 (manufactured by Gelest, Inc.) and "DOWSIL®" SH 1107 Fluid (manufactured by Dow Toray Industries, Inc.).

[0045] When the crosslinking agent has mercapto groups, it further promotes crosslinking via ene / thiol reactions with the C2-C8 alkenyl groups of the silicone polymer, thereby further suppressing swelling of the relief in relation to the ink. Examples of crosslinking agents having mercapto groups include mercapto-modified silicone oils having mercapto groups at both ends of the molecule or on the side chains of the molecule. Examples of mercapto-modified silicone oils having mercapto groups at both ends of the molecule include X-22-167B, X-22-167C (both manufactured by Shin-Etsu Chemical Co., Ltd.), and DMS-SM21 (manufactured by Gelest, INC.). Examples of mercapto-modified silicone oils having mercapto groups on the side chains of the molecule include KF-2001, KF-2004 (both manufactured by Shin-Etsu Chemical Co., Ltd.), SMS-022, SMS-042, SMS-142, and SMS-992 (all manufactured by Gelest, INC.).

[0046] When a silicone polymer having (meth)acryloyl groups is contained in the resin layer, it is preferable that the crosslinking agent also has (meth)acryloyl groups. Having (meth)acryloyl groups further promotes crosslinking and further suppresses swelling of the relief in relation to the ink. Examples of crosslinking agents having (meth)acryloyl groups include 1,10-bis(acryloyloxy)decane, tricyclodecanedimethanol diacrylate, trimethylolpropane triacrylate, and X-22-2445, X-22-164, X-22-164AS, X-22-164A, X-22-164B, X-22-164C, and X-22-164E (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0047] When a silicone polymer having epoxy groups, glycidyl groups, alcoholic hydroxyl groups, or phenolic hydroxyl groups is contained in the resin layer, the crosslinking agent is preferably an epoxy group or a glycidyl group. Having these functional groups further promotes crosslinking and further suppresses swelling of the relief in relation to the ink. Examples of crosslinking agents having these functional groups include "TEPIC®" (manufactured by Nissan Chemical Corporation) and "TECHMORE®" VG3101L (manufactured by Printec Co., Ltd.).

[0048] Among these, crosslinking agents having hydrosilyl groups or mercapto groups are preferred. Having hydrosilyl or mercapto groups in the crosslinking agent further promotes crosslinking with the silicone polymer, increases the crosslinking density of the relief, and further suppresses swelling of the relief in relation to the ink. Furthermore, systems using crosslinking agents with mercapto groups have superior pot life compared to systems using crosslinking agents with silanol or alkoxysilyl groups. Additionally, systems using crosslinking agents with mercapto groups have superior surface crosslinking and deep crosslinking properties compared to systems using crosslinking agents with (meth)acryloyl groups, thus improving image reproducibility. Moreover, systems using crosslinking agents with mercapto groups have superior thermal stability compared to systems using crosslinking agents with hydrosilyl groups.

[0049] From the viewpoint of improving the crosslinkability of the silicone polymer and its adhesion to the relief substrate, the content of the crosslinking agent in the resin layer is preferably 1.0 part by mass or more, and more preferably 2.0 parts by mass or more, per 100 parts by mass of the silicone polymer. In the case of a crosslinking agent having a hydrosilyl group, it is even more preferable to have 4.0 parts by mass or more. On the other hand, from the viewpoint of improving the flexibility of the relief, the content of the crosslinking agent in the resin layer is preferably 35 parts by mass or less, and more preferably 20 parts by mass or less, per 100 parts by mass of the silicone polymer.

[0050] Preferably, the resin layer further contains a reinforcing material. In this invention, the reinforcing material refers to a material that, when compounded into the resin layer, reinforces the crosslinked structure of the relief and exhibits a "reinforcing effect" that increases the mechanical strength of the relief and hysteresis loss during repeated deformation. The reinforcing material may also be called a filler, reinforcing filler, or reinforcing filler. In particular, reinforcing materials for rubber compounding may be called rubber fillers, rubber reinforcing fillers, or rubber reinforcing fillers. Fillers may also be called fillers. By including a reinforcing material, the actual or apparent crosslinking density in the relief can be increased, and swelling of the relief in relation to ink can be further suppressed. In addition, the mechanical strength of the relief can be increased, and the print durability of the flexographic printing plate can be improved. Furthermore, by compounding the reinforcing material into the pre-crosslinked resin layer, which has fluidity, and inducing thixotropy, the flow of the resin layer can be suppressed and its shape can be maintained. Examples of reinforcing materials include MQ silicone resin and silica powder.

[0051] MQ silicone resin is a monofunctional functional siloxane segment (R3SiO 1 / 2 :M units) and a tetrafunctional siloxane segment (SiO 4 / 2 The molecule contains (Q units), chemical formula: (R3SiO 1 / 2 ) m (SiO 4 / 2 ) n MQ is a general term for silicone compounds represented by , and numerous compounds exist depending on the ratio of M units to Q units and the type of functional group R contained in the M units. Because MQ silicone resin has higher transparency than silica powder, which will be described later, it can suppress light scattering in the exposure process described later and further improve image reproduction. Examples of functional groups R contained in the M units include organic groups such as methyl groups, vinyl groups, and phenyl groups, as well as hydrogen. The three functional groups R bonded to the Si atom may be the same or different.

[0052] Examples of such MQ silicone resins include methyl MQ silicone resin, vinyl MQ silicone resin, phenyl MQ silicone resin, methyl vinyl MQ silicone resin, methyl hydrogen MQ silicone resin, and methyl phenyl MQ silicone resin. Two or more of these may be used. Among these, MQ silicone resins selected from methyl MQ silicone resin, methyl vinyl MQ silicone resin, and methyl hydrogen MQ silicone resin are preferred from the viewpoint of further increasing the mechanical strength of the relief.

[0053] Examples of methyl MQ silicone resins include SQO-299 (manufactured by Gelest, INC.), Silmer Q20, Silmer Q12IDD, Silmer Q12XYL, Silmer Q9IDD, and Silmer Q9XYL (all manufactured by GSI Creos Corporation).

[0054] Examples of methyl vinyl MQ silicone resins include VQX-221 (manufactured by Gelest, INC.), Silmer VQ20, Silmer VQ92XYL, Silmer VQ92IDDD, Silmer G-180, Silmer G-181, and Silmer G-182 (all manufactured by GSI Creos Corporation).

[0055] Examples of methyl hydrogen MQ silicone resins include HQM-105, HQM-107 (both manufactured by Gelest, INC.), Silmer HQ20, and Silmer HQ203 (both manufactured by GSI Creos Corporation).

[0056] Examples of silica powder include fumed silica, precipitated silica, and calcined silica. Two or more of these may be used. Among these, fumed silica is more preferred from the viewpoint of rubber strength and transparency. The specific surface area of ​​silica powder by the BET method is 50 to 400 m². 2 / g is preferred. The silica powder may also be treated to be hydrophobic on the surface. Examples of hydrophobic silica powders include the "Aerosil®" R series (manufactured by Nippon Aerosil Co., Ltd.), which is fumed silica that has been hydrophobized, and FUMED SILICA, HEXAMETHYLDISILAZANE TREATED (manufactured by Gelest, INC., manufacturing code: SIS6962.0), and the "Nipseal®" SS series (manufactured by Tosoh Silica Co., Ltd.), which is precipitated silica that has been hydrophobized.

[0057] A commercially available silicone rubber compound in which a reinforcing material is uniformly dispersed in the silicone polymer may be used. Examples of commercially available silicone rubber compounds in which silica powder is uniformly dispersed in the silicone polymer include KE-931-U, KE-941-U, KE-951-U, KE-961T-U, KE-971T-U, KE-981T-U, KE-541-U, KE-551-U, KE-561-U, KE-571-U, KE-581-U, KE-5441-U, KE-5451-U, KE-5461-U, KE-5471-U, KE-520-U, KE-530B-2-U, KE-540B-2-U, and KE-40. Examples include 1EM-U, KE-501EM-U, KE-601EM-U, KE-701EM-U, KE-9411-U, KE-9511-U, KE-9611-U, KE-5142-U, KE-5182-U, KE-9390-U, KE-9490-U, KE-9590-U, KE-9690-U, KE-9790-U, KE-5490-U, KE-5590-U, KE-5690-U, KE-5790-U, KE-5890-U, KE-183-U, and KE-186-U (all manufactured by Shin-Etsu Chemical Co., Ltd.).

[0058] From the viewpoint of further suppressing swelling of the relief with respect to various inks, the content of reinforcing material in the resin layer is preferably 5% by mass or more, and more preferably 10% by mass or more. On the other hand, from the viewpoint of ensuring the flexibility of the relief, the content of reinforcing material in the resin layer is preferably 50% by mass or less, and more preferably 40% by mass or less.

[0059] The resin layer preferably further contains an ultraviolet absorber. An ultraviolet absorber refers to a material that absorbs ultraviolet rays and converts them into other energies such as heat and infrared rays and then emits them. It is sometimes called a UV absorber. By containing an ultraviolet absorber, the ultraviolet rays leaking in the lateral direction in the resin layer with respect to the incident direction of light during exposure can be absorbed, thereby suppressing the thickening of the image. As a result, a higher-definition image can be reproduced, particularly in the shadow region. As the ultraviolet absorber, benzotriazole-based ultraviolet absorbers, hydroxyphenyltriazine-based ultraviolet absorbers, malonic ester-based ultraviolet absorbers, etc. can be used. Among them, benzotriazole-based ultraviolet absorbers are preferred. Benzotriazole-based ultraviolet absorbers have both the ability to absorb the above-mentioned ultraviolet rays and the ability to capture radicals. Therefore, when the resin layer contains a photo radical generator as a photoinitiator, an unnecessary radical chain reaction in the lateral direction in the resin layer during exposure is also suppressed. Therefore, an even higher-definition image can be reproduced, particularly in the shadow region. Among them, in the present invention, it is preferable to use a benzotriazole-based ultraviolet absorber that is readily soluble in the silicone polymer in the resin layer. With such an ultraviolet absorber, aggregation and bleed-out of the ultraviolet absorber in the resin layer can be suppressed, and thus the above-mentioned high-definition effect can be efficiently obtained. Specifically, a benzotriazole-based ultraviolet absorber that can be dissolved at 0.01 mass% or more in dimethyl silicone oil having a kinematic viscosity of 100 mm 2 / s at 25°C is preferred. As commercially available benzotriazole-based ultraviolet absorbers that can be dissolved at 0.01 mass% or more in dimethyl silicone oil having a kinematic viscosity of 100 mm 2 / s at 25°C, there are "Tinuvin (registered trademark)" 213, "Tinuvin (registered trademark)" P, "Tinuvin (registered trademark)" 234, "Tinuvin (registered trademark)" 320, "Tinuvin (registered trademark)" 328, "Tinuvin (registered trademark)" 578 (all manufactured by BASF Japan Ltd.), RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.), etc.

[0060] From the viewpoint of achieving high resolution, the content of ultraviolet absorber in the resin layer is preferably 0.001% by mass or more, and more preferably 0.005% by mass or more. On the other hand, from the viewpoint of maintaining photocurability in the depth direction, the content of ultraviolet absorber in the resin layer is preferably 0.5% by mass or less, and more preferably 0.3% by mass or less.

[0061] The thickness of the resin layer is preferably 0.3 mm or more, which allows for sufficient relief depth in the printing plate described later and improves printability. The thickness of the resin layer is more preferably 0.5 mm or more. On the other hand, the thickness of the resin layer is preferably 5 mm or less, which allows the active light rays during exposure to reach the bottom sufficiently and further improves image reproduction. The thickness of the resin layer is more preferably 3 mm or less.

[0062] The printing plate master of the present invention has a substrate. The substrate is preferably one that exhibits excellent dimensional stability against heat and physical stress. Examples include plastic sheets such as polyester, and metal plates such as steel, stainless steel, and aluminum.

[0063] From the viewpoint of handling and flexibility, the substrate thickness is preferably 100 μm to 350 μm.

[0064] It is preferable to provide a primer layer or adhesive layer on at least one side of the substrate. By providing these layers, the adhesion strength between the substrate and the resin layer or floor layer can be improved.

[0065] The printing plate master according to the present invention may further have a floor layer between the substrate and the resin layer. The same material as the resin layer described above can be used as the floor layer material, but unlike the resin layer, the floor layer is not patterned. Examples of floor layers include a rubber layer obtained by photocrosslinking the same material as the resin layer described above, or a rubber layer obtained by thermal crosslinking a composition containing a silicone polymer or silicone rubber compound having 2 to 8 C12s, to which a thermal radical generating agent such as an organic peroxide has been added. It is also possible to make a portion of the resin layer closest to the substrate into a floor layer by exposing the entire surface from the substrate side for a short time. By providing a floor layer, the reproducibility of fine lines and independent points can be improved, and image reproducibility can be further improved. The silicone rubber content in the floor layer is preferably 40% by mass or more from the viewpoint of further suppressing swelling by various inks. More preferably 50% by mass or more, even more preferably 55% by mass or more, and still more preferably 60% by mass or more.

[0066] The floor layer may contain additives such as dyes, UV absorbers, and anti-halation agents.

[0067] From the viewpoint of improving the flexibility of the printing plate and printing plate, the thickness of the floor layer is preferably 30 μm or more, and more preferably 150 μm or more. On the other hand, from the viewpoint of improving the processability and handling of the printing plate and printing plate, the thickness of the floor layer is preferably 1,000 μm or less, and more preferably 800 μm or less.

[0068] The printing plate according to the present invention preferably has a cover film on a resin layer, which protects the surface of the resin layer and suppresses the adhesion of foreign matter. The resin layer may be in contact with the cover film, or there may be one or more other layers between the resin layer and the cover film. Examples of layers between the resin layer and the cover film include an anti-adhesion layer that prevents adhesion of the resin layer surface.

[0069] As the cover film, plastic sheets such as polyester (e.g., polyethylene terephthalate) or polyolefins (e.g., polyethylene and polypropylene) are preferably used. These plastic sheets have low ultraviolet absorption and high transparency, which can suppress light scattering in the exposure process described later. The thickness of the cover film is preferably 10 to 150 μm. The surface of the cover film may also be roughened to improve adhesion to the original image film.

[0070] The printing plate according to the present invention may further have a thermal mask layer on the resin layer. The thermal mask layer has the function of blocking ultraviolet light, and when irradiated with an infrared laser, part or all of the irradiated area sublimes or melts. This creates a difference in optical density between the irradiated and unirradiated areas. By drawing on the thermal mask layer with an infrared laser, it can perform the same function as a conventional original drawing film.

[0071] Furthermore, an adhesion adjustment layer may be provided between the thermal mask layer and the resin layer to improve adhesion between the thermal mask layer and the resin layer. Additionally, a release assist layer may be provided between the thermal mask layer and the cover film to suppress cohesive failure of the thermal mask layer when the cover film is peeled off.

[0072] Next, the method for manufacturing a printing plate according to the present invention will be explained using the case in which a resin layer is present on the substrate as an example.

[0073] A resin layer is formed on the substrate. Methods for forming the resin layer include, for example, casting and drying a resin layer-forming composition, bonding a separately formed resin layer sheet to a substrate on which a primer layer and adhesive layer have been formed as needed, or forming the resin layer by applying pressure to the resin layer-forming composition between the substrate and a cover film under heating or non-heating conditions. The resin layer-forming composition can be obtained, for example, by adding a crosslinking agent, reinforcing agent, ultraviolet absorber, and other additives and solvents as needed to a silicone polymer and / or silicone rubber and a photoreaction initiator, and stirring or kneading to thoroughly mix them.

[0074] When a floor layer is present between the substrate and the resin layer, for example, a method can be used in which a resin layer is formed on the substrate using the method described above, the entire resin layer is exposed to light, the entire resin layer is photocrosslinked to convert it into a floor layer, and then another resin layer is formed on this floor layer using the method described above. In particular, when the reproducibility of fine lines and independent points is required, it is also possible to form the floor layer by short-time exposure (back exposure) from the substrate side before peeling off the cover film.

[0075] Next, a method for manufacturing a printing plate according to the present invention will be described. From the viewpoint of productivity and image reproducibility of the printing plate, a method for manufacturing a printing plate can be described as having, in this order, an exposure step in which light is irradiated onto the printing plate master to partially photocrosslink the resin layer, and a development step in which the uncrosslinked portion of the resin layer is removed.

[0076] First, the exposure process will be explained. In the case of a so-called CTP plate having a thermal mask layer, if there is a cover film, it is peeled off, and an image corresponding to the original image film is drawn using a laser drawing machine. Then, the resin layer is partially photocrosslinked by ultraviolet irradiation. If the printing plate does not have a thermal mask layer, the resin layer is partially photocrosslinked by ultraviolet irradiation through the original image film. If the resin layer contains a silicone polymer, it is preferable to crosslink the silicone polymer in the exposure process to form silicone rubber. As ultraviolet light, light with a wavelength of 300 to 400 nm is preferred. Examples of lamps used for ultraviolet irradiation include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, and chemical lamps.

[0077] Next, the development process will be described. The exposed printing plate is immersed in a developer solution, and the uncrosslinked portions of the resin layer are removed with the developer solution using a brush-type or spray-type developer, thereby forming a relief on the substrate and obtaining a printing plate. The developer solution preferably contains a solvent that can dissolve or swell the silicone polymer, and may contain additives such as surfactants as needed. The developer solution temperature during development is preferably 15 to 40°C.

[0078] After development, it is preferable to dry the printing plate at 50-70°C for about 10 minutes. If necessary, a post-exposure procedure may be performed by irradiating it with active light in air or vacuum.

[0079] A printing plate obtained using the printing plate master according to the present invention has a relief on a substrate containing 40% by mass or more of silicone rubber. Examples of the substrate include those exemplified as the substrate for the printing plate master. Examples of the silicone rubber that forms the relief include those exemplified as the silicone rubber that forms the resin layer of the printing plate master.

[0080] Next, the method for manufacturing printed materials according to the present invention will be described. Flexographic printing is a printing method in which ink is applied to the upper surface of a relief on a printing plate and the ink is transferred from the relief to the substrate by pressing the relief onto the substrate. The method for manufacturing printed materials according to the present invention preferably includes the steps of applying ink to the relief of the printing plate obtained by the above method and transferring the ink to the substrate.

[0081] Examples of printing presses used in the method for manufacturing printed materials of the present invention include flexographic printing presses such as inline type, center drum type, and stack type.

[0082] Preferably, solvent inks, water-based inks, UV-curing inks, or EB-curing inks are used. Preferably, solvent inks contain pigments or dyes, vehicles, organic solvents, etc. Specifically, for example, XA-55 (manufactured by Sakata Inx Co., Ltd.) is an example. Preferably, water-based inks contain pigments, water-soluble resins, water, alcohols, etc. Specifically, for example, XS-903 (manufactured by DIC Corporation) is an example. Preferably, UV-curing inks contain pigments, resins such as acrylic oligomers, acrylate monomers, polymerization initiators, etc. Specifically, for example, PHA (manufactured by T&K TOKA Corporation), "FLASH DRY" (registered trademark) (manufactured by Toyo Ink Co., Ltd.), "UVAFLEX" (registered trademark) Y77 (manufactured by Zeller + Gmelin) is an example. Preferably, EB-curing inks contain pigments, resins such as acrylic oligomers, acrylate monomers, etc. Specifically, examples include "GelFlex EB" (registered trademark) (manufactured by Sakata Inx Corporation). [Examples]

[0083] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these. The names of the compounds used, for which abbreviations are used, are shown below.

[0084] (Silicone polymer) DMS-V35: α,ω-terminal vinyl polydimethylsiloxane (manufactured by Gelest, INC., weight-average molecular weight: 49,000, number of vinyl groups in the polymer chain: 2) DMS-S35: α,ω-terminal silanol polydimethylsiloxane (manufactured by Gelest, INC., weight-average molecular weight: 49,000, number of silanol groups in the polymer chain: 2) VGM-021: Vinyl silicone gum (manufactured by Gelest, INC., weight-average molecular weight: 500,000, vinylmethylsiloxane units: 0.2-0.3 mol%) TF-36: Vinyl silicone gum (manufactured by Dow Toray Industries, Ltd., weight-average molecular weight: 500,000, vinylmethylsiloxane units: 2.5~2.7 mol%).

[0085] (Silicone rubber) KMP-597: Silicone rubber powder (manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 5 μm).

[0086] (Crosslinking agent) RD-1: Methylhydrogensiloxane-dimethylsiloxane copolymer “SILASTIC®” RD-1 Rubber Additive (manufactured by Dow Toray Industries, Inc.) Methyl silicate 51: Silicate oligomer (manufactured by Colcoat Co., Ltd.) KF-2001: Mercapto-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0087] (Photoacid generator) PAG-121: PAG-121 is an oxime sulfonate-based nonionic photoacid generator with absorption at a wavelength of 365 nm (manufactured by BASF Japan Ltd).

[0088] (Photoradical generator) "Irgacure (registered trademark)" 1173: (Manufactured by BASF Japan Ltd.).

[0089] (UV absorber) "Tinuvin (registered trademark)" 328: (Manufactured by BASF Japan Ltd., kinematic viscosity at 25°C: 100 mm) 2 The soluble concentration of / s in dimethyl silicone oil is 1% by mass or more.

[0090] (Reinforcement material) VQX-221: Methyl vinyl MQ silicone resin dispersion (manufactured by Gelest, INC., 50% xylene dispersion of methyl vinyl MQ silicone resin, vinyl group: 0.4~0.6 Eq / kg) KE-951-U: Silicone rubber compound (manufactured by Shin-Etsu Chemical Co., Ltd., vinyl silicone gum: 80% by mass, hydrophobic fumed silica: 20% by mass).

[0091] The evaluation of each example and comparative example was performed using the following method.

[0092] (1) Photosensitivity Using the flexographic printing plate masters and flexographic printing plates prepared in each example and comparative example, the difference in the insolubilization rate of the resin layer before and after exposure was calculated by the following method, and the photosensitivity was evaluated. A larger difference in the insolubilization rate of the resin layer before and after exposure indicates superior photosensitivity.

[0093] (1-1) Insolubilization rate of the resin layer before exposure Three 50ml screw-cap bottles (Laboran screw-cap bottles No. 7, manufactured by AS ONE Corporation) were prepared, and 45ml each of the following three types of immersion solvents was injected into each screw-cap bottle. [Immersion Solvent-1] Toluene / Isooctane = 50 / 50% by mass [Immersion Solvent-2] Water / Ethanol = 50 / 50% by mass [Immersion Solvent-3] Tetrahydrofuran / N,N-dimethylformamide = 50 / 50% by mass In each example and comparative example, the flexographic printing plates prepared were cut into three 2cm x 2cm pieces. For plates with a cover film, the cover film was peeled off, and the weight (Weight A) of each sample was measured. After weight measurement, each sample was placed in a screw-top tube filled with one of the three types of immersion solvents, sealed, and left to stand at 40°C for 24 hours. After standing, each screw-top tube was placed in a high-speed shaker: Cute Mixer ASCM-1 (manufactured by AS ONE Corporation) and shaken at a speed of 1,500 rpm for 3 hours. After removing each sample from the screw-top tube, it was dried at 120°C for 1 hour, and the weight (Weight B) of each dried sample was measured. After weight measurement, each sample was rubbed on both sides for 15 minutes each with a cloth soaked in the immersion solvent to completely remove any remaining resin layer. Then, it was dried at 120°C for 1 hour, and the weight (Weight C) of each dried sample was measured. Using the obtained weights, the insolubilization rate [mass%] of the resin layer before exposure was calculated using the following formula. {(Weight B-Weight C) / (Weight A-Weight C)}×100.

[0094] For Comparative Example 3, where the resin layer was thermally crosslinked at the flexographic printing plate stage and weight C could not be measured, the insolubilization rate [mass%] of the resin layer before exposure was calculated using the following formula. (Weight B / Weight A) x 100.

[0095] Of the calculated insolubilization rates, the lowest value was used as the insolubilization rate of the resin layer before exposure.

[0096] (1-2) Insolubilization rate of the resin layer after exposure In Examples 1-13, Comparative Examples 1-2, and Comparative Examples 4-5, the solid areas of the flexographic printing plates were cut to a size of 2 cm x 2 cm. For plates with a cover film, the cover film was peeled off, and the weight (weight D) of each sample was measured. Here, the solid area of ​​the flexographic printing plate refers to the raised relief portion where ink adheres to the entire surface at a uniform size during printing. In halftone printing, it refers to the raised portion with a halftone area ratio of 100%. In Comparative Example 3, the prepared flexographic printing plate original 10 was subjected to a high-intensity chemical lamp (TL-K 40W / 10R, manufactured by Philips) with an integrated light intensity of 12,000 mJ / cm². 2 After full exposure from the resin layer side, the samples were cut to a size of 2 cm x 2 cm, the cover film was peeled off, and the weight (weight D) of the sample was measured. Each sample after weight measurement was placed in a screw tube into which the immersion solvent that yielded the lowest insolubilization rate in (1-1) was injected, sealed, and left to stand at 40°C for 24 hours. After standing, each screw tube was set in a Cute Mixer ASCM-1 and shaken at a shaking speed of 1,500 rpm for 3 hours. Each sample removed from the screw tube was dried at 120°C for 1 hour, and the weight (weight E) of each sample after drying was measured. Using the obtained weights D and E, as well as the weight C of each example and comparative example obtained in (1-1), the insolubilization rate [mass %] of the resin layer after exposure was calculated using the following formula. {(Weight E-Weight C) / (Weight D-Weight C)}×100.

[0097] For Comparative Example 3, where the resin layer was thermally crosslinked at the flexographic printing plate stage and weight C could not be measured in (1-1), the insolubilization rate [mass%] of the resin layer after exposure was calculated using the following formula. (Weight E / Weight D) x 100.

[0098] (1-3) Difference in the insolubilization rate of the resin layer before and after exposure Using the insolubilization rates of the resin layer before and after exposure for each sample obtained in (1-1) and (1-2) above, the difference in the insolubilization rate of the resin layer before and after exposure [mass %] was calculated using the following formula. (Isolubilization rate of the resin layer after exposure) - (Isolubilization rate of the resin layer before exposure).

[0099] (2) Swelling tendency with various inks As an indicator of swelling properties for various inks in each example and comparative example, the swelling properties for the following components, which are commonly used in various inks and are particularly prone to swelling the relief, were evaluated. • Water-based ink: Water was prepared as a typical solvent. • Solvent ink: Ethanol was prepared as a typical solvent. • UV-curing inks and EB-curing inks: Trimethylolpropane ethoxylate triacrylate (TMP(EO)3TA) and 1,6-hexanediol diacrylate (HDDA) were prepared as typical acrylic monomers.

[0100] After measuring the weight of samples cut from the solid areas of the flexographic printing plates prepared in each example and comparative example to a size of 2 cm x 2 cm, the samples were immersed in the above components of various inks at 40°C for 24 hours, and the weight after immersion was measured. The ease of swelling was evaluated using the following scoring system based on the weight change rate before and after immersion ({(weight after immersion - weight before immersion) / weight before immersion} × 100).

[0101] Excellent: Weight change rate before and after ink immersion is less than 5%. Very good: Weight change rate before and after ink immersion is between 5% and less than 10%. Good: Weight change rate before and after ink immersion is between 10% and 15%. Bad: The weight change rate before and after ink immersion is 15% or more.

[0102] (3) Image reproducibility The reproducibility of the halftone dots in the flexographic printing plates prepared in Examples 4-7, 10-13, and Comparative Examples 1-4 was observed using an optical microscope: "ECLIPSE®" L200N (manufactured by Nikon Solutions Co., Ltd.). In the highlight region with a halftone dot area ratio of 1% to 30%, the better the reproduction of halftone dots with smaller area ratios, the better the image reproducibility. On the other hand, in the shadow region with a halftone dot area ratio of 70% to 99%, the better the reproduction of halftone dots with larger area ratios, the better the image reproducibility. In other words, the wider the reproducible range from halftone dots with small area ratios to those with large area ratios, the better the image reproducibility.

[0103] (Example 1) [Preparation of flexographic printing plates] In a container, 95.14 g of DMS-V35 as a silicone polymer and 4.76 g of RD-1 as a crosslinking agent were added, and the mixture was stirred until the components were homogeneous to obtain mixture A. Next, in a separate container, 50 g of 2-pentanone as a solvent and 0.10 g of bis(2,4-heptanedionato)platinum complex (0.05 g as platinum), a platinum compound that absorbs at a wavelength of 365 nm, were added, and the mixture was stirred until the components were homogeneous to obtain mixture B. Mixture B was added to mixture A, and the mixture was stirred until the components were homogeneous to obtain resin layer forming composition 1.

[0104] A 188 μm thick polyester (PET) film (Panaclea® ACM188, manufactured by Panac Co., Ltd.) with an adhesive layer was used as the substrate. The resin layer forming composition 1 was cast onto the adhesive layer so that the plate thickness (substrate + resin layer) after drying was 1.14 mm, and the plate was dried at 60°C for 2.5 hours to form a resin layer and obtain a flexographic printing plate original 1.

[0105] [Preparation of flexographic printing plates] Flexographic printing plate 1 was cut to a size of 10cm x 10cm, and a high-intensity chemical lamp TL-K 40W / 10R was used to achieve an integrated light intensity of 12,000 mJ / cm². 2 The entire surface was exposed from the resin layer side to obtain a flexographic printing plate 1 having a solid area across its entire surface.

[0106] The photosensitivity and susceptibility to swelling with various inks of the obtained flexographic printing plate 1 and flexographic printing plate 1 were evaluated using the method described above. The evaluation results are shown in Table 1.

[0107] (Example 2) In a container, 76.10 g of DMS-V35 as a silicone polymer, 20.00 g of KMP-597 as a silicone rubber, and 3.80 g of RD-1 as a crosslinking agent were added and stirred until the components were homogeneous to obtain mixture A. Next, in a separate container, 50 g of 2-pentanone as a solvent and 0.10 g of bis(2,4-heptanedionato)platinum complex (0.05 g as platinum) as a metal compound were added and stirred until the components were homogeneous to obtain mixture B. Mixture B was added to mixture A and stirred until the components were homogeneous to obtain resin layer forming composition 2.

[0108] A flexographic printing plate master 2 and a flexographic printing plate 2 having a solid area covering the entire surface were obtained in the same manner as in Example 1, except that resin layer forming composition 2 was used instead of resin layer forming composition 1.

[0109] The photosensitivity and susceptibility to swelling with various inks of the obtained flexographic printing plate 2 and flexographic printing plate 2 were evaluated using the method described above. The evaluation results are shown in Table 1.

[0110] (Example 3) In a container, 94.34 g of DMS-S35 as a silicone polymer and 4.72 g of methyl silicate 51 as a crosslinking agent were added, and the mixture was stirred until the components were homogeneous to obtain mixture A. Next, in a separate container, 50 g of 2-pentanone as a solvent and 0.94 g of PAG-121 as a photoacid generator were added, and the mixture was stirred until the components were homogeneous to obtain mixture B. Mixture B was added to mixture A, and the mixture was stirred until the components were homogeneous to obtain resin layer forming composition 3.

[0111] Except for using resin layer-forming composition 3 instead of resin layer-forming composition 1, a flexographic printing plate master 3 and a flexographic printing plate 3 having a solid area covering the entire surface were obtained in the same manner as in Example 1.

[0112] The photosensitivity and susceptibility to swelling with various inks of the obtained flexographic printing plate 3 and flexographic printing plate 3 were evaluated using the method described above. The evaluation results are shown in Table 1.

[0113] (Example 4) [Preparation of flexographic printing plates] A 300ml resin container containing 95.90g of VGM-021 as a silicone polymer, 4.00g of RD-1 as a crosslinking agent, and 0.10g of bis(2,4-heptanedionato) platinum complex (0.05g as platinum) as a metal compound was placed in a rotation / revolution type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000 rpm for 20 minutes to homogenize the components, thereby obtaining resin layer forming composition 4.

[0114] A 188 μm thick polyester (PET) film with an adhesive layer (Panac Co., Ltd.'s "Panacrea®" ACM188) was used as the substrate, and a biaxially oriented polypropylene film "Trefan®" #10 (thickness: 10 μm, manufactured by Toray Industries, Inc.) was used as the cover film. A resin layer was formed between the adhesive layer surface of the substrate and the cover film by applying pressure to form a resin layer with a plate thickness (substrate + resin layer + cover film thickness) of 0.70 mm. After that, a high-brightness chemical lamp TL-K 40W / 10R was used to achieve an integrated light intensity of 12,000 mJ / cm². 2 The entire surface was exposed from the cover film side to form a floor layer approximately 0.50 mm thick on the substrate. Next, the cover film was peeled off from the floor layer, and then a resin layer was formed between the floor layer surface and the cover film by applying pressure to form a resin layer so that the plate thickness (thickness of substrate + floor layer + resin layer + cover film) was 1.15 mm, thus creating the flexographic printing plate original 4.

[0115] [Preparation of flexographic printing plates] A negative film for print image evaluation was vacuum-sealed onto the cover film of the flexographic printing plate 4, and a high-intensity chemical lamp TL-K 40W / 10R was used to achieve an integrated light intensity of 12,000 mJ / cm².2 The negative film used for print image evaluation was exposed from the side. The negative film for print image evaluation contained two different halftone images with AM screen rulings of 175 lpi and 300 lpi, each with halftone images in 1% increments with a halftone area ratio of 1% to 30% as highlight areas, halftone images in 1% increments with a halftone area ratio of 70% to 99% as shadow areas, and a 50 mm x 50 mm solid image (100% halftone area ratio). After peeling off the cover film, the film was developed using a batch exposure and developing machine (Inglese W43, manufactured by Inglese, srl) with "Isopar®" E (isoparaffin-based solvent, manufactured by ExxonMobil Chemical) at a developer temperature of 25°C, dried at 60°C for 10 minutes, and then further exposed using a high-intensity chemical lamp TL-K 40W / 10R with an integrated light intensity of 12,000 mJ / cm². 2 After post-exposure, a flexographic printing plate 4 was obtained.

[0116] The obtained flexographic printing plate 4 and flexographic printing plate 4 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0117] (Example 5) A 300ml resin container containing 95.80g of VGM-021 as a silicone polymer, 4.00g of KF-2001 as a crosslinking agent, and 0.20g of "Irgacure®" 1173 as a photoradical generator was placed in a rotation / revolution type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000 rpm for 20 minutes to homogenize the components, thereby obtaining resin layer forming composition 5.

[0118] A flexographic printing plate master 5 and a flexographic printing plate 5 were obtained in the same manner as in Example 4, except that resin layer forming composition 5 was used instead of resin layer forming composition 4.

[0119] The obtained flexographic printing plate master 5 and flexographic printing plate 5 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0120] (Example 6) A 300ml resin container containing 85.80g of VGM-021 as a silicone polymer and 20.00g of VQX-221 as a reinforcing material was placed in a rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000rpm for 20 minutes. Then, 10.00g of xylene contained in VQX-221 was volatilized and removed using a vacuum dryer. Next, 4.00g of KF-2001 as a crosslinking agent and 0.20g of "Irgacure(registered trademark)" 1173 as a photoradical generator were added, and the resin container was placed in a rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000rpm for 20 minutes to homogenize the components and obtain resin layer forming composition 6.

[0121] A flexographic printing plate master 6 and a flexographic printing plate 6 were obtained in the same manner as in Example 4, except that resin layer forming composition 6 was used instead of resin layer forming composition 4.

[0122] The obtained flexographic printing plate master 6 and flexographic printing plate 6 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0123] (Example 7) 95.80g of KE-951-U as a silicone rubber compound, 4.00g of KF-2001 as a crosslinking agent, and 0.20g of "Irgacure®" 1173 as a photoradical generator were added to the mixing section of a batch kneader (Batch Kneader KDRJ-2, manufactured by Dalton Co., Ltd.), and the mixture was kneaded for 20 minutes under the conditions of drive shaft: 120 rpm and driven shaft: 80 rpm. The resulting mixture was passed between the rolls of a two-roll mill (tabletop two-roll kneading mill φ75, manufactured by Kodaira Seisakusho Co., Ltd.) 10 times to homogenize the components and obtain resin layer forming composition 7.

[0124] A flexographic printing plate master 7 and a flexographic printing plate 7 were obtained in the same manner as in Example 4, except that resin layer forming composition 7 was used instead of resin layer forming composition 4.

[0125] The obtained flexographic printing plate master 7 and flexographic printing plate 7 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0126] (Comparative Example 1) As the flexographic printing plate master, "RESOLUCIA®" DF114HR2 (manufactured by Toray Industries, Inc., content of silicone polymer and / or silicone rubber in the resin layer: 0% by mass) was used.

[0127] [Preparation of flexographic printing plates] Cut a DF114HR2 sheet to 10cm x 10cm, and use a high-brightness chemical lamp (TL-K 40W / 10R) from the substrate side to achieve an integrated light output of 700mJ / cm². 2 Back exposure was performed. Next, the cover film was peeled off and the substrate was mounted on an external drum-type platesetter (CDI SPARK2530 manufactured by ESCO Graphics Co., Ltd.) equipped with a fiber laser that emits light in the infrared region, with the substrate side in contact with the drum, and a test pattern was output at 2.4 J / cm². 2 The image was drawn using a laser, and an image mask was formed from the thermal mask layer. The test pattern included two different halftone images with AM screen rulings of 175 lpi and 300 lpi, each containing halftone images with halftone areas ranging from 1% to 30% in 1% increments as highlight areas, halftone images with halftone areas ranging from 70% to 99% in 1% increments as shadow areas, and a 50 mm x 50 mm solid image (100% halftone area). Subsequently, under atmospheric conditions, the same high-intensity chemical lamp TL-K 40W / 10R was used for back exposure, with an integrated light intensity of 12,000 mJ / cm². 2The main exposure was performed from the image mask side. Then, using a batch exposure and developing machine (Inglese W43), the image was developed for 80 seconds with tap water adjusted to 25°C, and dried in a 60°C oven for 10 minutes. Next, a high-intensity chemical lamp TL-K 40W / 10R was used to achieve an integrated light intensity of 12,000 mJ / cm². 2 Post-exposure was then performed to obtain a flexographic printing plate 8.

[0128] The flexographic printing plate master, "RESOLUCIA®" DF114HR2, and the resulting flexographic printing plate 8 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0129] (Comparative Example 2) A flexographic printing plate 9 was obtained in the same manner as in Comparative Example 1, except that "AWP(registered trademark)-DEW (manufactured by Asahi Kasei Corporation, content of silicone polymer and / or silicone rubber in the resin layer: 0% by mass) was used as the flexographic printing plate master instead of "RESOLUCIA(registered trademark)" DF114HR2.

[0130] The flexographic printing plate master, "AWP(registered trademark)"-DEW, and the resulting flexographic printing plate 9 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0131] (Comparative Example 3) [Preparation of flexographic printing plates] In the mixing section of a batch kneader (KDRJ-2), 89.35 g of KE-951-U as a silicone rubber compound, 0.65 g of C-1A (benzoyl peroxide, active ingredient: 50% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.) as a vulcanizing agent, and 10.00 g of carbon black as a laser radiation absorber were added, and the mixture was kneaded for 20 minutes under the conditions of driving shaft: 120 rpm and driven shaft: 80 rpm. The resulting mixture was passed between the rolls of a two-roll mill (tabletop two-roll kneading machine, φ75) 10 times to homogenize the components and obtain resin layer forming composition 8.

[0132] A 188 μm thick polyester (PET) film with an adhesive layer (Panaclea® ACM188, manufactured by Panac Co., Ltd.) was used as the substrate, and a biaxially oriented polypropylene film "Trefan®" #10 (thickness: 10 μm, manufactured by Toray Industries, Inc.) was used as the cover film. A resin layer was formed by applying pressure to the adhesive layer surface of the substrate and the cover film to form a resin layer, so that the plate thickness (thickness of substrate + resin layer + cover film) was 1.15 mm. After peeling off the cover film, the resin layer was thermally crosslinked by heating at 120°C for 10 minutes to obtain a flexographic printing plate master 10.

[0133] [Preparation of flexographic printing plates] A flexographic printing plate 10 was engraved using a fiber laser direct engraving machine ("Premium" 1300S, Hell Gravure Systems) under the following conditions: resolution: 2,540 dpi, laser power: 100%, and dot shape profile: slope 60°, so that the shape of the image area conformed to a predetermined test pattern. The test pattern included two different halftone images with AM screen rulings of 175 lpi and 300 lpi, with halftone images in 1% increments ranging from 1% to 30% as highlight areas, halftone images in 1% increments ranging from 70% to 99% as shadow areas, and a solid 50 mm x 50 mm image (100% halftone area). Afterwards, the plate surface was rubbed with a pig bristle brush and washed with running water to remove engraving residue, thereby obtaining the flexographic printing plate 10.

[0134] The obtained flexographic printing plate master 10 and flexographic printing plate 10 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0135] (Comparative Example 4) [Preparation of flexographic printing plates] In a pressure-resistant reaction vessel equipped with a stirring device and a temperature-controlling jacket, 125 g of water and 2 g of Adekarya Soap SE1025 (ammonium salt of α-sulfo(1-nonylphenoxy)methyl-2-(2-propenyloxy)ethoxy-poly(oxy-1,2-ethanediyl), manufactured by ADEKA Corporation), a reactive emulsifier, were charged. The internal temperature was raised to 80°C, and an oily mixture of monomers consisting of 10 g of styrene, 60 g of butadiene, 23 g of butyl acrylate, 5 g of methacrylic acid, and 2 g of acrylic acid, and 2 g of t-dodecyl mercaptan, and an aqueous solution consisting of 28 g of water, 1.2 g of sodium peroxodisulfate, 0.2 g of sodium hydroxide, and 2 g of Adekarya Soap SE1025, were added at a constant flow rate over 5 and 6 hours, respectively. Next, the polymerization reaction was completed by maintaining the temperature at 80°C for 1 hour to produce a copolymer latex, which was then cooled. Furthermore, the resulting copolymer latex was adjusted to pH 7 with sodium hydroxide, unreacted monomers were removed by steam stripping, and the mixture was filtered through a 200-mesh wire mesh. Finally, the solid content of the filtrate was adjusted to 40% by mass to obtain an aqueous dispersion of the hydrophilic copolymer.

[0136] In the mixing section of a batch kneader (KDRJ-2), 110 g of an aqueous dispersion of the hydrophilic copolymer prepared by the above method and 75 g of D-KX405 (manufactured by Kraton), a styrene-butadiene-styrene block copolymer, were added and kneaded at 140°C. Subsequently, a mixture of 40g of liquid polybutadiene LBR-352 (manufactured by Kuraray Co., Ltd.), 5g of liquid carboxylic acid-modified acrylic polymer CB-3060 (manufactured by Soken Chemical Co., Ltd.), 10g of photopolymerizable monomers 1,9-nonanediol diacrylate and 10g of 1,6-hexanediol dimethacrylate, 5g of photopolymerization initiator 2,2-dimethoxyphenylacetophenone, 2g of surfactant NT-12 (polyoxyethylene alkyl ether, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and 5g of polymerization inhibitor 2,6-di-t-butyl-p-cresol was added in small amounts over 15 minutes, and then kneaded for a further 20 minutes. The resulting mixture was passed through the gap between the rolls of a two-roll mill (tabletop two-roll kneading mill, φ75) 10 times to homogenize the components and obtain resin layer forming composition 9.

[0137] A 188 μm thick polyester (PET) film with an adhesive layer (Panaclea® ACM188, manufactured by Panac Co., Ltd.) was used as the substrate, and a biaxially oriented polypropylene film "Trefan®" #10 (thickness: 10 μm, manufactured by Toray Industries, Inc.) was used as the cover film. A resin layer was formed between the adhesive layer surface of the substrate and the cover film by applying pressure to the resin layer-forming composition 9 so that the plate thickness (thickness of substrate + resin layer + cover film) was 1.15 mm, thereby forming a resin layer and creating a flexographic printing plate master 11. A flexographic printing plate 11 was obtained in the same manner as in Comparative Example 1, except that the flexographic printing plate master 11 was used instead of "RESOLUCIA®" DF114HR2 as the flexographic printing plate master.

[0138] The obtained flexographic printing plate master 11 and flexographic printing plate 11 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0139] (Comparative Example 5) 70.00 g of the resin layer forming composition 9 and 30.00 g of KMP-597 as silicone rubber were placed in the mixing section of a batch kneader (batch kneader KDRJ-2), and the mixture was kneaded for 20 minutes under the conditions of a driving shaft at 120 rpm and a driven shaft at 80 rpm. The resulting mixture was passed through the gap between the rolls of a two-roll mill (tabletop two-roll kneading machine, φ75) 10 times to homogenize the components and obtain the resin layer forming composition 10.

[0140] A 188 μm thick polyester (PET) film with an adhesive layer (Panaclea® ACM188, manufactured by Panac Co., Ltd.) was used as the substrate, and a biaxially oriented polypropylene film "Trefan®" #10 (thickness: 10 μm, manufactured by Toray Industries, Inc.) was used as the cover film. A resin layer was formed by applying a resin layer composition 10 between the adhesive layer surface of the substrate and the cover film under pressure to create a plate thickness (substrate + resin layer + cover film thickness) of 1.15 mm, thereby obtaining a flexographic printing plate master 12. A high-intensity chemical lamp (TL-K 40W / 10R) was used to illuminate the resin layer side of the obtained flexographic printing plate master 12 with an integrated light intensity of 12,000 mJ / cm². 2 The entire surface was exposed from the resin layer side to obtain a flexographic printing plate 12 with a solid area across its entire surface.

[0141] The photosensitivity and susceptibility to swelling with various inks of the obtained flexographic printing plate master 12 and flexographic printing plate 12 were evaluated using the method described above. The evaluation results are shown in Table 1.

[0142] (Example 8) 60.00 g of the resin layer forming composition 9 and 40.00 g of KMP-597 as silicone rubber were placed in the mixing section of a batch kneader (KDRJ-2), and the mixture was kneaded for 20 minutes under the conditions of a driving shaft at 120 rpm and a driven shaft at 80 rpm. The resulting mixture was passed through the rollers of a two-roll mill (tabletop two-roll kneading machine, φ75) 10 times to homogenize the components and obtain the resin layer forming composition 11.

[0143] Except for using resin layer-forming composition 11 instead of resin layer-forming composition 10, the same procedure as in Comparative Example 5 was used to obtain a flexographic printing plate master 13 and a flexographic printing plate 13 having a solid area covering the entire surface. The obtained flexographic printing plate master 13 and flexographic printing plate 13 were evaluated for photosensitivity and susceptibility to swelling with various inks using the method described above. The evaluation results are shown in Table 1.

[0144] (Example 9) 50.00 g of the resin layer forming composition 9 and 50.00 g of KMP-597 as silicone rubber were added to the mixing section of a batch kneader (KDRJ-2), and the mixture was kneaded for 20 minutes under the conditions of a driving shaft at 120 rpm and a driven shaft at 80 rpm. The resulting mixture was passed through the rollers of a two-roll mill (tabletop two-roll kneading machine, φ75) 10 times to homogenize the components and obtain the resin layer forming composition 12.

[0145] Except for using resin layer-forming composition 12 instead of resin layer-forming composition 10, the same procedure as in Comparative Example 5 was used to obtain a flexographic printing plate master 14 and a flexographic printing plate 14 having a solid area covering the entire surface. The obtained flexographic printing plate master 14 and flexographic printing plate 14 were evaluated for photosensitivity and susceptibility to swelling with various inks using the method described above. The evaluation results are shown in Table 1.

[0146] (Example 10) A 300ml resin container containing 89.80g of VGM-021 as a silicone polymer and 20.00g of VQX-221 as a reinforcing material was placed in a rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000rpm for 20 minutes. Then, 10.00g of xylene contained in VQX-221 was volatilized and removed using a vacuum dryer. Next, 0.20g of "Irgacure(registered trademark)" 1173 was added as a photoradical generator, and the resin container was placed in the rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310 again and stirred and mixed at 2,000rpm for 20 minutes to homogenize the components and obtain resin layer forming composition 13.

[0147] Instead of resin layer forming composition 4, resin layer forming composition 13 was used, and the integrated light amount during exposure was 60,000 mJ / cm². 2 A flexographic printing plate master 15 and a flexographic printing plate 15 were obtained in the same manner as in Example 4, except for the change made to [specific part of the original].

[0148] The obtained flexographic printing plate master 15 and flexographic printing plate 15 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality, respectively, using the method described above. The evaluation results are shown in Table 1.

[0149] (Example 11) A 300ml resin container containing 87.50g of TF-36 as a silicone polymer and 20.00g of VQX-221 as a reinforcing agent was placed in a rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000rpm for 20 minutes. Then, 10.00g of xylene contained in VQX-221 was volatilized and removed using a vacuum dryer to obtain a precursor for resin layer forming composition 14. Next, 97.50g of the resin layer forming composition 14 precursor as a silicone rubber compound and 2.50g of "Irgacure®" 1173 as a photoradical generator were added to the kneading section of a kneader (batch kneader KDRJ-2, manufactured by Dalton Co., Ltd.), and kneaded for 20 minutes under the conditions of driving shaft: 120rpm and driven shaft: 80rpm. The resulting mixture was passed through the gap between the rolls of a two-roll mill (tabletop two-roll mixing mill, φ75, manufactured by Kodaira Seisakusho Co., Ltd.) 10 times to homogenize its components and obtain a resin layer forming composition 14.

[0150] When resin layer forming composition 14 is used instead of resin layer forming composition 4, the integrated light amount during exposure is 60,000 mJ / cm². 2 A flexographic printing plate master 16 and a flexographic printing plate 16 were obtained in the same manner as in Example 4, except for the change made to [specific part of the original].

[0151] The obtained flexographic printing plate master 16 and flexographic printing plate 16 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0152] (Example 12) A 300ml resin container containing 87.46g of TF-36 as a silicone polymer and 20.00g of VQX-221 as a reinforcing material was placed in a rotational / revolving type mixer "Awatori Rentaro" atmospheric pressure type ARE-310, and stirred and mixed at 2,000rpm for 20 minutes. Then, 10.00g of xylene contained in the VQX-221 was volatilized and removed using a vacuum dryer to obtain a precursor for resin layer forming composition 15. Next, 97.46 g of the resin layer forming composition 15 precursor as a silicone rubber compound, 2.50 g of "Irgacure®" 1173 as a photoradical generator, and 0.04 g of "Tinuvin®" 328 as an ultraviolet absorber were added to the mixing section of a mixer (batch kneader KDRJ-2, manufactured by Dalton Co., Ltd.), and the mixture was kneaded for 20 minutes under the conditions of driving shaft: 120 rpm and driven shaft: 80 rpm. The resulting mixture was passed between the rolls of a two-roll mill (tabletop two-roll kneading mill φ75, manufactured by Kodaira Seisakusho Co., Ltd.) 10 times to homogenize the components and obtain the resin layer forming composition 15.

[0153] Instead of resin layer forming composition 4, resin layer forming composition 15 was used, and the integrated light amount during exposure was 60,000 mJ / cm². 2 A flexographic printing plate master 17 and a flexographic printing plate 17 were obtained in the same manner as in Example 4, except for the change made to [specific part of the original].

[0154] The obtained flexographic printing plate master 17 and flexographic printing plate 17 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0155] (Example 13) A 188 μm thick polyester (PET) film with an adhesive layer (Panac Co., Ltd.'s "Panacrea®" ACM188) was used as the substrate, and a biaxially oriented polypropylene film "Trefan®" #10 (thickness: 10 μm, manufactured by Toray Industries, Inc.) was used as the cover film. A resin layer was formed between the adhesive layer surface of the substrate and the cover film by applying pressure to the resin layer-forming composition 15 described in Example 12, so that the plate thickness (thickness of substrate + resin layer + cover film) was 1.15 mm, thereby obtaining a flexographic printing plate master 18. A high-intensity chemical lamp (TL-K 40W / 10R) was used to illuminate the substrate side of the obtained flexographic printing plate master 18 with an integrated light intensity of 5,000 mJ / cm². 2 Back exposure was performed to form the floor layer.

[0156] Instead of the flexographic printing plate 4, a flexographic printing plate 18 was used, which had a floor layer formed by back exposure, and the integrated light intensity during exposure was 60,000 mJ / cm². 2 A flexographic printing plate 18 was obtained in the same manner as in Example 4, except for the change made to [specific component].

[0157] The obtained flexographic printing plate master 18 and flexographic printing plate 18 were evaluated for photosensitivity, susceptibility to swelling with various inks, and image reproduction quality using the method described above. The evaluation results are shown in Table 1.

[0158] [Table 1]

Claims

1. A flexographic printing plate master having a resin layer on a substrate containing a total of 40% by mass or more of silicone polymer and / or silicone rubber and a photoreaction initiator, The resin layer contains 40% by mass or more of silicone polymer, A flexographic printing plate master, wherein the silicone polymer has functional groups selected from hydrosilyl groups, silanol groups, C2-C8 alkenyl groups, (meth)acryloyl groups, epoxy groups, glycidyl groups, alcoholic hydroxyl groups, and phenolic hydroxyl groups.

2. The flexographic printing plate according to claim 1, wherein the silicone polymer has two or more functional groups selected from silanol groups and alkenyl groups having 2 to 8 carbon atoms in its polymer chain.

3. The flexographic printing plate according to claim 1, further comprising a crosslinking agent in the resin layer.

4. The flexographic printing plate according to claim 3, wherein the crosslinking agent has a hydrosilyl group or a mercapto group.

5. The flexographic printing plate according to claim 1, wherein the photoreaction initiator contains a metal compound.

6. The flexographic printing plate according to claim 5, wherein the metal compound contains a platinum compound.

7. The flexographic printing plate according to claim 6, wherein the platinum compound has absorption at a wavelength of 365 nm.

8. The flexographic printing plate according to claim 1, wherein the photoreaction initiator contains a photoradical generator.

9. The flexographic printing plate according to claim 1, wherein the resin layer further contains a reinforcing material.

10. A method for manufacturing a flexographic printing plate, comprising, in this order, an exposure step of irradiating the flexographic printing plate master according to claim 1 with light to partially photocrosslink the resin layer, and a development step of removing the uncrosslinked portion of the resin layer.

11. A method for manufacturing a printed material, comprising the steps of: applying ink to the relief of a flexographic printing plate obtained by the manufacturing method described in claim 10; and transferring the ink to a substrate.

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