Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/09—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers
  • G03F7/095—Photosensitive materials characterised by structural details, e.g. supports, auxiliary layers having more than one photosensitive layer
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
  • G03F7/2014—Contact or film exposure of light sensitive plates such as lithographic plates or circuit boards, e.g. in a vacuum frame
  • G03F7/2016—Contact mask being integral part of the photosensitive element and subject to destructive removal during post-exposure processing
  • G03F7/202—Masking pattern being obtained by thermal means, e.g. laser ablation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
  • B41C1/1008—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials
  • B41C1/1033—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials by laser or spark ablation
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
  • G03F7/032—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders
  • G03F7/033—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders the binders being polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists

Definitions

• the present invention relates to a photosensitive composition for a flexographic printing plate and a method for manufacturing a flexographic printing plate.
• a method of directly drawing a digital image with a laser without using a negative film by CTP (Computer To Plate) technology has been widely used.
• CTP Computer To Plate
• a photosensitive resin composition layer, an infrared ablation layer that can be cut off by infrared rays, and a cover film are formed on a substrate such as PET (polyethylene terephthalate) resin.
• PET polyethylene terephthalate
• the infrared ablation layer that can be ablated by infrared rays generally contains an infrared absorber and a binder, which are materials opaque to radiation other than infrared rays.
• a technique of arranging microcells on the surface of a printing plate is known as a technique for further improving the definition of a printed image and improving ink transferability at the time of printing.
• the laser drawing apparatus used in the manufacturing process of the flexographic printing plate is also being improved in resolution, and the laser resolution is also increasing from the conventional 2540 DPI to 4000 DPI and further to 5080 DPI.
• the flexographic printing plate requires further microfabrication by laser drawing.
• a technique for obtaining an infrared ablation layer having excellent infrared laser drawing property is required.
• Patent Document 1 proposes a technique of using polyamide as a binder for an infrared ablation layer
• Patent Document 2 proposes a technique for partially saponifying a binder of an infrared ablation layer having a degree of saponification of 60 to 100 mol%.
• Techniques using polyvinyl acetate and cationic polymers have been proposed.
• Patent Document 3 a copolymer composed of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene or a copolymer composed of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene is hydrogenated as a binder for the infrared ablation layer.
• the technology to be used has been proposed.
• the polyamide binders and binders using partially saponified polyvinyl acetate and cationic polymers disclosed in Patent Documents 1 and 2 include styrene derivatives and conjugated diene monomers generally used for the photosensitive resin composition layer. Since the adhesion to the thermoplastic elastomer containing the polymer of the above is poor, there is a problem that the infrared ablation layer and the photosensitive resin composition layer are easily peeled off in the manufacturing process of the printing plate.
• the infrared ablation layer is obtained by hydrogenating a copolymer composed of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene or a copolymer composed of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene disclosed in Patent Document 3.
• a binder When a binder is used, there is a problem that sufficient characteristics cannot be obtained for drawing with an infrared laser.
• the present invention provides a photosensitive resin composition for a flexographic printing plate, which has no harmful effect in the manufacturing process of the flexographic printing plate and has an infrared ablation layer excellent in laser drawing property. With the goal.
• the present invention is as follows.
• the resin in the (c) infrared ablation layer contains a hydrogenated additive of a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, or a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene.
• the primary particle size of carbon black contained in the infrared ablation layer is 13 nm or more and 25 nm or less. Photosensitive resin composition for flexographic printing plate.
• the resin in the infrared ablation layer is a hydrogenated product of a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, or a hydrogen additive of a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene.
• R- calculated by the following formula (1) is 11.0 or more and 13
• the resin in the (c) infrared ablation layer is The photosensitive resin composition for a flexographic printing plate according to any one of the above [1] to [6], which contains a styrene-conjugated diene copolymer having a styrene content of 40% by mass or more and 80% by mass or less.
• the resin in the (c) infrared ablation layer is The photosensitive for a flexographic printing plate according to any one of [1] to [6] above, which contains a hydrogenated styrene-conjugated diene copolymer having a styrene content of 30% by mass or more and 70% by mass or less. Sex resin composition.
• a photosensitive resin composition for a flexographic printing plate which has no harmful effect in the manufacturing process of the printing plate and has an infrared ablation layer excellent in laser drawing property.
• the present embodiment a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
• the following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents.
• the present invention can be appropriately modified and carried out within the scope of the gist thereof.
• the photosensitive resin composition for a flexographic printing plate of the present embodiment is (A): Support and (B): A photosensitive resin composition layer on the support (a) and containing a thermoplastic elastomer having a copolymerization site of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene. (C): An infrared ablation layer, which is laminated on the photosensitive resin composition layer, contains a resin and carbon black, can be cut off by an infrared laser, and is a light shielding layer other than infrared rays.
• the resin in the (c) infrared ablation layer contains a hydrogenated product of a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, or a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene.
• the primary particle diameter of carbon black contained in the (c) infrared ablation layer is 13 nm or more and 25 nm or less.
• the (a) support used in the photosensitive resin composition for a flexographic printing plate of the present embodiment is not limited to the following, and examples thereof include a polyester film.
• the polyester used for the support include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like.
• the thickness of the support is not particularly limited, but is preferably 50 to 300 ⁇ m from the viewpoint of strength and handleability.
• an adhesive layer may be provided on the support (a) for the purpose of enhancing the adhesive force between (a) the support and (b) the photosensitive resin composition layer described later. Examples of the adhesive layer include the adhesive layer described in International Publication No. 2004/10471.
• the photosensitive resin composition for a flexographic printing plate of the present embodiment has (b) a photosensitive resin composition layer on the (a) support.
• the (b) photosensitive resin composition layer may be directly laminated on the (a) support, or a predetermined adhesive layer or the like may be formed between them.
• the photosensitive resin composition layer contains a thermoplastic elastomer (b-1) described later, preferably an ethylenically unsaturated compound (b-2), a photopolymerization initiator (b-3), and a liquid diene. May be further contained, and if necessary, an auxiliary additive component may be further contained.
• the photosensitive resin composition layer contains a thermoplastic elastomer (b-1) having a copolymerization moiety of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene. Having a copolymerization moiety means that the thermoplastic elastomer (b-1) may have an moiety formed by other monomers other than monovinyl-substituted aromatic hydrocarbons and conjugated diene. It means.
• thermoplastic elastomer (b-1) having a copolymerization moiety between the monovinyl-substituted aromatic hydrocarbon and the conjugated diene
• the (b) photosensitive resin composition layer having excellent durability can be obtained.
• the thermoplastic elastomer (b-1) is preferably a block copolymer having a polymer block made of a monovinyl-substituted aromatic hydrocarbon and a polymer block made of a conjugated diene.
• the monovinyl-substituted aromatic hydrocarbon constituting the thermoplastic elastomer (b-1) is not limited to the following, but for example, styrene, t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, and the like.
• Styrene is preferable from the viewpoint that the photosensitive resin composition layer can be smoothly molded at a relatively low temperature. These may be used alone or in combination of two or more.
• the conjugated diene constituting the thermoplastic elastomer (b-1) is not limited to the following, but is, for example, butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1, Examples thereof include 3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadien, 3-butyl-1,3-octadien, and chloroprene. These may be used alone or in combination of two or more. Butadiene is preferable as the conjugated diene from the viewpoint of the durability of the photosensitive resin composition for flexographic printing plates of the present embodiment.
• the thermoplastic elastomer (b-1) preferably has a number average molecular weight of 20,000 or more and 300,000 or less, and more preferably 30,000 or more and 250,000 or less. It is preferable, and more preferably 50,000 or more and 200,000 or less.
• the number average molecular weight of the thermoplastic elastomer (b-1) can be measured by gel permeation chromatography (GPC) and is expressed in terms of polystyrene-equivalent molecular weight.
• thermoplastic elastomer (b-1) is a block copolymer having a polymer block made of monovinyl-substituted aromatic hydrocarbons and a polymer block made of conjugated diene
• the thermoplastic elastomer (b-1) The block copolymer constituting the above is, for example, a linear block copolymer represented by the following general formula group (I) and / or a linear block represented by the following general formula group (II). Includes copolymers or radial block copolymers.
• A represents a monomer unit derived from a monovinyl-substituted aromatic hydrocarbon.
• B represents a monomeric unit derived from a conjugated diene.
• X is silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyhalogenated hydrocarbon compound, carboxylic acid ester compound, polyvinyl compound, bisphenol type epoxy compound, alkoxysilane compound, halogenated silane compound, ester compound and the like.
• the residue of the coupling agent or the residue of the polymerization initiator such as a polyfunctional organic lithium compound is shown.
• n, k and m represent integers of 1 or more, and are, for example, 1 to 5.
• the content of the monomer unit derived from the conjugated diene and the monomer unit derived from the monovinyl-substituted aromatic hydrocarbon in the thermoplastic elastomer (b-1) is determined by using a nuclear magnetic resonance apparatus ( 1 H-NMR). Can be measured. Specifically, 1 H-NMR measuring device is JNM-LA400 (manufactured by JEOL, trade name), deuterated chloroform is used as a solvent, the sample concentration is 50 mg / mL, the observation frequency is 400 MHz, and the chemical is used.
• 1 H-NMR measuring device is JNM-LA400 (manufactured by JEOL, trade name)
• deuterated chloroform is used as a solvent
• the sample concentration is 50 mg / mL
• the observation frequency is 400 MHz
• chemical is used.
• the pulse delay can be set to 2.904 seconds
• the number of scans can be set to 64
• the pulse width can be set to 45 °
• the measurement temperature can be set to 25 ° C.
• the copolymerization ratio (mass ratio) of the monovinyl-substituted aromatic hydrocarbon and the conjugated diene constitutes the photosensitive resin composition for a flexo printing plate of the present embodiment (b) photosensitive.
• the monovinyl-substituted aromatic hydrocarbon / conjugated diene 10/80 or more and 90/20 or less is preferable, and 10/90 or more and 85/15 or less is more preferable. It is more preferably 10/90 or more and 60/40 or less.
• the ratio of the monovinyl-substituted aromatic hydrocarbons is 10 or more in the mass ratio, (b) sufficient hardness can be obtained in the photosensitive resin composition layer, and appropriate printing can be performed by normal printing pressure. can.
• the ratio of the monovinyl-substituted aromatic hydrocarbon is 90 or less in the mass ratio, (b) an appropriate hardness is obtained in the photosensitive resin composition layer, and the ink can be sufficiently transferred to the printing target in the printing step.
• thermoplastic elastomer (b-1) has other functional groups introduced, chemically modified such as hydrogenation, and other than monovinyl-substituted aromatic hydrocarbons and conjugated diene.
• the components of may be copolymerized.
• the content of the thermoplastic elastomer (b-1) in the photosensitive resin composition layer is from the viewpoint of durability of the flexo printing plate obtained by using the photosensitive resin composition for the flexo printing plate of the present embodiment. Therefore, when the total amount of the photosensitive resin composition layer is 100% by mass, it is preferably 40% by mass or more, more preferably 40% by mass or more and 80% by mass or less, and 45% by mass or more and 80% by mass or less. It is more preferably 45% by mass or more, and even more preferably 75% by mass or less.
• the photosensitive resin composition layer preferably contains the ethylenically unsaturated compound (b-2).
• the ethylenically unsaturated compound (b-2) is a compound having an unsaturated double bond capable of radical polymerization.
• the ethylenically unsaturated compound (b-2) is not limited to the following, but is, for example, olefins such as ethylene, propylene, vinyltoluene, styrene and divinylbenzene; acetylenes; (meth) acrylic acid and / Or derivatives thereof; haloolefins; unsaturated nitriles such as acrylonitrile; derivatives of acrylamide and methacrylicamide; unsaturated dicarboxylic acids such as maleic anhydride, maleic acid and fumaric acid and their derivatives; vinyl acetates; N-vinyl Examples thereof include pyrrolidone; N-vinylcarbazole; N-substituted maleimide compound and the like.
• olefins such as ethylene, propylene, vinyltoluene, styrene and divinylbenzene
• acetylenes (meth) acrylic acid and / Or
• (meth) acrylic acid and / or its derivatives are preferable from the viewpoint of abundance of types.
• the derivative is not limited to the following, but is, for example, an alicyclic compound having a cycloalkyl group, a bicycloalkyl group, a cycloalkenyl group, a bicycloalkenyl group, etc .; a benzyl group, a phenyl group, a phenoxy group, or the like.
• the (meth) acrylic acid and / or a derivative thereof is not limited to the following, and for example, diacrylates and dimethacrylates of alkanediols such as hexanediol and nonanediol; ethylene glycol, diethylene glycol, propylene glycol, and the like.
• the ethylenically unsaturated compound (b-2) includes at least one (meth) acrylate. It is preferable to use, and it is more preferable to use at least one kind of bifunctional (meth) acrylate.
• the number average molecular weight (Mn) of the ethylenically unsaturated compound (b-2) is preferably 100 or more from the viewpoint of ensuring non-volatility, and is a phase with other components such as a resin in the photosensitive resin composition layer. From the viewpoint of solubility, it is preferably less than 1000, and more preferably 200 or more and 800 or less.
• the content of the ethylenically unsaturated compound (b-2) in the photosensitive resin composition layer is the printing resistance of the flexographic printing plate obtained by using the photosensitive resin composition for the flexographic printing plate of the present embodiment.
• the total amount of the photosensitive resin composition when the total amount of the photosensitive resin composition is 100% by mass, it is preferably 2% by mass or more and 30% by mass or less, and 2% by mass. It is more preferably 25% by mass or less, and further preferably 2% by mass or more and 20% by mass or less.
• the photosensitive resin composition layer preferably contains a photopolymerization initiator (b-3).
• the photopolymerization initiator (b-3) is a compound that absorbs light energy and generates radicals.
• the photopolymerization initiator (b-3) includes a site that functions as a disintegrating photopolymerization initiator, a hydrogen abstraction type photopolymerization initiator, a hydrogen abstraction type photopolymerization initiator, and a site that functions as a disintegrating photopolymerization initiator. Examples thereof include compounds having the same molecule.
• As the photopolymerization initiator (b-3) various organic carbonyl compounds can be used, and aromatic carbonyl compounds are particularly preferable.
• the content of the photopolymerization initiator (b-3) in the photosensitive resin composition layer is the printing resistance of the flexographic printing plate produced by using the photosensitive resin composition for the flexographic printing plate of the present embodiment.
• the total amount of the photosensitive resin composition is 100% by mass, it is preferably 0.1% by mass or more and 10% by mass or less, preferably 0.1. It is more preferably mass% or more and 5 mass% or less, and further preferably 0.5 mass% or more and 5 mass% or less.
• the photopolymerization initiator (b-3) is not limited to the following, and is, for example, benzophenone, 4,4-bis (diethylamino) benzophenone, 3,3', 4,4'-benzophenone tetracarboxylic acid.
• Benzophenones such as anhydrides, 3,3', 4,4'-tetramethoxybenzophenone; anthraquinones such as t-butyl anthraquinone and 2-ethylanthraquinone; 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichloro Thioxanthons such as thioxanthone; Michler ketone; diethoxyacetophenone, 2,2-dimethoxy-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1-hydroxycyclohexyl-phenylketone, 2-Methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholino-propane-1-one, 2-benzyl-2-dimethyl Amino-1- (4-morpholin
• the photosensitive resin composition layer preferably contains a liquid diene.
• a liquid diene is a compound having a liquid carbon-carbon double bond.
• the "liquid” of "liquid diene” means a property having the property of being easily fluidly deformed and solidified into a deformed shape by cooling, and when an external force is applied. It shows the property of instantly deforming in response to the external force and recovering the original shape in a short time when the external force is removed.
• the liquid diene is not limited to the following, but is not limited to, for example, liquid polybutadiene, liquid polyisoprene, modified liquid polyisoprene, modified liquid polyisoprene, liquid acrylic nitrile-butadiene copolymer, liquid styrene-. Examples include butadiene copolymers.
• the liquid diene is a copolymer having a diene component of 50% by mass or more.
• the number average molecular weight of the liquid diene is not particularly limited as long as it is liquid at 20 ° C., but the mechanical strength and handling of the flexo printing plate obtained by using the photosensitive resin composition for the flexo printing plate of the present embodiment.
• Liquid polybutadiene is preferable as the liquid diene from the viewpoint of the photosensitive resin composition for the flexographic printing plate of the present embodiment and the mechanical properties of the flexographic printing plate using the same.
• the 1,2-vinyl bond amount of the liquid diene is from the viewpoint of making the hardness of the photosensitive resin composition for the flexo printing plate of the present embodiment and the flexo printing plate using the same suitable. 1% or more and 80% or less are preferable, 5% or more and 70% or less are more preferable, and 5% or more and 65% or less are further preferable.
• the 1,2-vinyl bond amount is defined as 1,2-, among the conjugated diene monomers incorporated in the 1,2-bond, 3,4-bond, and 1,4-bond bond modes. Percentage of what is incorporated in the bond.
• the 1,2-polybutadiene which is a liquid polybutadiene having a 1,2-vinyl bond, has a high reactivity of radical polymerization because the vinyl having a double bond is a side chain, and (b) photosensitive. It is preferable from the viewpoint of increasing the hardness of the resin composition layer.
• the liquid polybutadiene is usually a mixture of 1,2-polybutadiene having a 1,2-vinyl bond and 1,4-polybutadiene having a 1,4-vinyl bond, but the flexographic printing plate of the present embodiment.
• 1,4-Polybutadiene includes cis-type 1,4-polybutadiene and trans-type 1,4-polybutadiene.
• 1,4-polybutadiene has a vinyl group as a double bond inside in both the cis type and the trans type, it has low reactivity in radical polymerization and can finally produce a flexible resin. It is possible. When a plurality of liquid polybutadienes having different 1,2-vinyl bond amounts are mixed and used, the average value thereof is taken as the 1,2-vinyl bond content.
• liquid polybutadiene having a 1,2-vinyl bond amount of 5% or less and liquid polybutadiene having a 1,2-vinyl bond amount of 80% or more are mixed to adjust the total 1,2-vinyl bond amount. It is preferable to do so.
• the 1,2-vinyl bond amount can be determined from the peak ratio of 1 H-NMR (magnetic resonance spectrum) of liquid polybutadiene.
• the content of the liquid diene in the photosensitive resin composition layer is determined from the viewpoint of the mechanical strength of the photosensitive resin composition for a flexographic printing plate of the present embodiment and the flexographic printing plate using the same.
• the total amount of the layers is 100% by mass, it is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 40% by mass or less, and further preferably 20% by mass or 40% by mass or less.
• the auxiliary additive component is not particularly limited, but is, for example, a polar group-containing polymer, a plasticizer other than liquid diene, a thermal polymerization inhibitor other than a stabilizer, an antioxidant, an ultraviolet absorber, a dye / pigment, and the like. Can be mentioned.
• the polar group-containing polymer is not limited to the following, but has, for example, a hydrophilic group such as a carboxyl group, an amino group, a hydroxyl group, a phosphoric acid group and a sulfonic acid group, and a polar group such as a salt thereof.
• a hydrophilic group such as a carboxyl group, an amino group, a hydroxyl group, a phosphoric acid group and a sulfonic acid group
• a polar group such as a salt thereof.
• Examples include water-soluble or water-dispersible copolymers.
• the carboxyl group-containing NBR contains a carboxyl group-containing NBR, a carboxyl group-containing SBR, a polymer of an aliphatic conjugated diene containing a carboxyl group, an emulsified polymer of an ethylenically unsaturated compound having a phosphoric acid group or a carboxyl group, and a sulfonic acid group.
• examples thereof include polyurethane and carboxyl group-containing butadiene latex.
• the carboxyl group-containing butadiene latex is preferable as the polar group-containing polymer from the viewpoint of obtaining high resolution in the flexographic printing plate using the photosensitive resin composition for flexographic printing plate of the present embodiment.
• These polar group-containing polymers may be used alone or in combination of two or more.
• the plasticizing agent other than the liquid diene is not limited to the following, but for example, hydrocarbon oils such as naphthenic oil and paraffin oil; liquid acrylic nitrile-butadiene copolymer, liquid styrene-butadiene copolymer and the like.
• Conjugate diene rubber mainly composed of liquid diene; polystyrene, sevatinic acid ester, phthalate ester and the like having a number average molecular weight of 2000 or less can be mentioned. These may have a hydroxyl group or a carboxyl group at the terminal. Further, these may be imparted with a photopolymerizable reactive group such as a (meth) acryloyl group.
• These plasticizers may be used alone or in combination of two or more.
• thermal polymerization inhibitor and the antioxidant those usually used in the field of resin materials or rubber materials can be used. Specific examples thereof include phenolic materials.
• the phenolic material is not limited to the following, but is, for example, vitamin E, tetrakis- (methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate. ) Methan, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methyl) Benzyl) -4-methylphenyl acrylate and the like can be mentioned.
• These thermal polymerization inhibitors and antioxidants may be used alone or in combination of two or more.
• Examples of the ultraviolet absorber include known benzophenone-based, sultylate-based, acrylonitrile-based, metal complex salt-based, and hindered amine-based compounds. Further, the dye / pigment shown below may be used as an ultraviolet absorber. Examples of the ultraviolet absorber include, but are not limited to, 2-ethoxy-2'-ethyloxalic acid bisanilide, 2,2'-dihydroxy-4-methoxybenzophenone and the like.
• the dye / pigment is effective as a coloring means for improving visibility.
• the dye include, but are not limited to, water-soluble basic dyes, acid dyes, direct dyes, etc., water-insoluble sulfide dyes, oil-soluble dyes, disperse dyes, and the like. ..
• anthraquinone-based, indigoid-based, and azo-based dyes are preferable, and azo-based oil-oil-soluble dyes and the like are more preferable.
• the pigment examples include, but are not limited to, natural pigments, synthetic inorganic pigments, synthetic organic pigments, and the like, and examples of synthetic organic pigments include azo-based, triphenylmethane-based, quinoline-based, and anthraquinone-based pigments. , Phthalocyanine type.
• the addition amount of all the above-mentioned auxiliary additive components in the photosensitive resin composition layer is 0% by mass or more and 10% by mass or less when the total amount of (b) the photosensitive resin composition layer is 100% by mass. It is preferable that it is 0% by mass or more and 5% by mass or less, and more preferably 0% by mass or more and 3% by mass or less.
• (C) Infrared ablation layer In the photosensitive resin composition for flexographic printing plates of the present embodiment, (c) an infrared ablation layer is laminated on the above-mentioned (b) photosensitive resin composition layer. (C) The infrared ablation layer contains a resin and carbon black, can be cut off by an infrared laser, and has a function as a light shielding layer other than infrared rays.
• (C) In order to process the infrared ablation layer with high definition, it is necessary to improve the sensitivity of the infrared ablation layer to the laser.
• the laser sensitivity means that when drawn with the same laser energy, the volume to be ablated is larger, especially in the depth direction.
• (C) In order to improve the laser sensitivity of the infrared ablation layer, it is effective to reduce the primary particle diameter of carbon black. This is because the surface area of carbon black increases as the primary particle size of carbon black decreases. It receives an infrared laser that has passed through the resin on the surface of carbon black and converts energy into heat to improve the temperature of the resin. By increasing the surface area of carbon black, the area of carbon black that receives the laser increases, and the area of the resin / carbon black interface also increases, so that the energy of the laser can be efficiently transferred to the resin as heat, and the laser sensitivity. Is improved.
• the carbon black in the (c) infrared ablation layer has a primary particle size of 13 nm or more and 25 nm or less.
• the primary particle size of carbon black is 13 nm or more, the self-aggregating force between carbon blacks tends to increase. Can be prevented from becoming too large, good dispersibility can be obtained, and even higher laser sensitivity can be obtained.
• the primary particle diameter is 25 nm or less, the desired high laser sensitivity can be obtained, and a high-definition image can be obtained.
• the primary particle size of carbon black is not too small, and the primary particle size of carbon black is 15 nm or more and 25 nm or less. Is preferable. Further, from the viewpoint of excellent removal of the infrared ablation layer at the interface with (b) the photosensitive resin composition layer after laser ablation, the primary particle size of carbon black is more preferably 15 nm or more and 23 nm or less. , 15 nm or more and 20 nm or less is more preferable.
• Photosensitive resin composition A photosensitive resin composition for a flexographic printing plate having a more excellent shape without uneven shielding of light rays other than infrared rays due to excellent removal of the infrared ablation layer at the interface of the layer. , And a flexographic printing plate using the same can be obtained.
• the primary particle size of carbon black contained in the infrared ablation layer can be determined by observing with an electron microscope. It can be obtained by the method described in the examples.
• the primary particle size of carbon black contained in the infrared ablation layer can be controlled within the above numerical range by selecting an appropriate particle size from various commercially available products.
• carbon black has a small structure. Due to the small structure, the contact area between carbon black and the resin is increased, the infrared laser sensitivity is improved by improving the dispersibility, and further, (c) the infrared ablation layer and (b) the photosensitive resin composition layer are used. Adhesion is improved. Specifically, the amount of DBP absorbed by carbon black is preferably 40 cm 3/100 g or more and 80 cm 3/100 g or less, more preferably 50 cm 3/100 g or more and 80 cm 3/100 g or less, and 55 cm 3/100 g or more and 80 cm. It is more preferably 3/100 g or less. The above-mentioned effects can be seen in this range.
• the amount of DBP absorbed is the amount of DBP (dibutyl phthalate) absorbed by 100 g of carbon black, and can be measured by the method defined by JIS K6217-4. Specifically, it can be measured by the method described in Examples. The larger the structure, the larger the value of DBP absorption, and the smaller the structure, the smaller the value.
• the DBP oil absorption amount of carbon black contained in the infrared ablation layer can be controlled within the above numerical range by selecting an appropriate value from various commercially available products.
• the carbon black contained in the infrared ablation layer preferably has a pH of 6.0 or more and 8.5 or less. In this range, the compatibility with the resin is excellent, the dispersibility of carbon black is improved, and the infrared laser sensitivity is improved.
• the pH of carbon black is more preferably 6.5 or more and 8.0 or less, and further preferably 7.0 or more and 8.0 or less.
• the pH of carbon black can be measured by preparing a mixed solution of carbon black and distilled water and using a pH meter equipped with a glass electrode. Specifically, it can be measured according to ASTM D1512.
• the pH of carbon black contained in the infrared ablation layer can be controlled within the above numerical range by selecting an appropriate pH value from various commercially available products.
• Carbon black is classified into, for example, furnace black, channel black, thermal black, acetylene black, lamp black, etc. according to the manufacturing method, and furnace black is preferable in order to obtain desired characteristics.
• Furnace black is a carbon black obtained by blowing petroleum-based or coal-based oil into a high-temperature gas and incompletely burning it, and can be produced by a widely known method.
• As the carbon black carbon black conventionally used for forming a black matrix can be used as long as the above-mentioned various conditions are satisfied.
• the resin of the infrared ablation layer is a copolymer of a monovinyl-substituted aromatic hydrocarbon and a conjugated diene, or a monovinyl-substituted aromatic. It shall contain a hydrogenated additive of a polymer of a group hydrocarbon and a conjugated diene. From the viewpoint of obtaining the above effects, the content of the hydrogen additive in the resin is the copolymer of the monovinyl-substituted aromatic hydrocarbon and the conjugated diene, or the copolymer of the monovinyl-substituted aromatic hydrocarbon and the conjugated diene.
• the photosensitive resin composition for a flexographic printing plate of the present embodiment has excellent dispersibility of the carbon black in the resin, and the infrared laser sensitivity is also higher than that when other resins are used. It is considered that this is because the polarities of the resin and the carbon black are at an appropriate distance. From this point of view, (c) the combination of the resin used for the infrared ablation layer and the carbon black is important.
• the Hansen solubility parameter can be used as an index of the combination of the resin used for the infrared ablation layer and the carbon black.
• the distance between the resin and the HSP of the carbon black (Hansen solubility parameter (hereinafter, may be referred to as "HSP") is important.
• HSP Hansen solubility parameter
• the Hansen solubility parameter (HSP) is a value used for predicting the solubility of a substance, which was announced by Charles M. Hansen in 1967. "Two substances with similar intramolecular interactions are: It is a parameter based on the idea that it is easy to dissolve in each other. HSP is composed of the following three parameters (unit: MPa 0.5 ).
• HSPiP Hansen Solubility Parameters in Practice
• the Hansen solubility parameter obtained by using the above-mentioned software "HSPiP: Hansen Solubility Parameters in Practice" for a personal computer is used.
• R (4 ⁇ 2 + ⁇ 2 + ⁇ 2 ) 0.5
• R is preferably 11.0 or more and 13.0 or less, and 11.0 or more and 12 It is more preferably 5.5 or less, and further preferably 11.0 or more and 12.5 or less.
• ⁇ , ⁇ , and ⁇ are as shown below.
• the Hansen solubility parameter (HSP value) of the resin in the infrared ablation layer and the Hansen solubility parameter (HSP value) of the carbon black can be controlled by selecting the composition of the resin and the type of carbon black.
• the HSP value can be controlled by adjusting the polarity of the surface. Specifically, when the carbon black is oxidized to have a high polarity (low pH), the HSP value of the carbon black shifts to the high polarity side. Further, as the particle size of carbon black is smaller, the HSP value of carbon black tends to be higher in polar ones and lower in polar ones.
• the value of R in the above formula (1) can be controlled within the above numerical range.
• the vinyl aromatic hydrocarbon compound used for the copolymer of the monovinyl-substituted aromatic hydrocarbon contained in the resin in the infrared ablation layer and the conjugated diene (hereinafter, may be referred to as a copolymer).
• styrene t-butylstyrene, divinylbenzene, 1,1-diphenylstyrene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, Examples thereof include monomers such as vinylpyridine, p-methylstyrene, tertiary butylstyrene, ⁇ -methylstyrene, and 1,1-diphenylethylene.
• styrene is preferable because the photosensitive resin composition for flexographic printing plates can be smoothly molded at a relatively low temperature (hereinafter referred to as high moldability).
• These monomers may be used alone or in combination of two or more.
• the conjugated diene used in the copolymer is not limited to the following, and for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1 , 3-Hexadiene, 4,5-diethyl-1,3-octadien, 3-butyl-1,3-octadien, and chloroprene monomers, and 1,3-butadiene in particular is from the viewpoint of wear resistance. preferable.
• These monomers may be used alone or in combination of two or more.
• the content and ratio of monovinyl-substituted aromatic hydrocarbons in the copolymer can be measured using a nuclear magnetic resonance apparatus ( 1 H-NMR).
• 1 H-NMR nuclear magnetic resonance apparatus
• the content of styrene when the monovinyl-substituted aromatic hydrocarbon is styrene that is, when the copolymer is a styrene-conjugated diene copolymer.
• the film thickness of the (c) infrared ablation layer of the photosensitive resin composition for flexographic printing plate of the present embodiment has a light-shielding property against ultraviolet rays in the step of performing an exposure treatment on the photosensitive resin composition for flexographic printing plate. From the viewpoint of securing, it is better to be thick, and from the viewpoint of enhancing ablation, it is better to be thin. From the above viewpoint, (c) the film thickness of the infrared ablation layer is preferably 0.1 ⁇ m or more and 20 ⁇ m or less, more preferably 0.5 ⁇ m or more and 15 ⁇ m or less, and further preferably 1.0 ⁇ m or more and 10 ⁇ m or less.
• the optical density of the infrared ablation layer is preferably 2 or more, and more preferably 3 or more.
• the optical density can be measured using a D200-II transmission densitometer (manufactured by GretagMacbeth). Further, the optical density is so-called ISO visual, and the light to be measured is in a wavelength region of about 400 to 750 nm.
• the infrared ablation layer may contain a dispersant for the purpose of assisting the dispersion of carbon black.
• a dispersant for example, a compound having an adsorbing portion capable of interacting with the surface functional group of the infrared absorber and a resin compatible portion capable of being compatible with the resin is preferable.
• the adsorbing portion of the dispersant is not limited to the following, and examples thereof include an amino group, an amide group, a urethane group, a carboxyl group, a carbonyl group, a sulfone group, and a nitro group, and an amino group, an amide group, and the like. Urethane groups are preferred.
• the resin compatible portion include, but are not limited to, saturated alkyl, unsaturated alkyl, polyether, polyester, poly (meth) acrylic, and polyol.
• the method for forming the infrared ablation layer is not limited to the following, but for example, first, a resin solution is prepared using a predetermined solvent, carbon black and a dispersant are added thereto, and carbon black is used as a resin solution. After being dispersed in, it is coated on a cover film such as a polyester film, and then this cover film is laminated or press-bonded to (b) a photosensitive resin composition layer to shield non-infrared rays that can be cut off by an infrared laser. There is a method of transferring the layer and the like.
• the method for dispersing carbon black in the resin solution is not limited to the following, but includes forced stirring with a stirring blade, stirring using ultrasonic waves and various mills, and the like, and a method using these in combination is effective.
• a method in which the resin, carbon black and the dispersant are pre-kneaded using an extruder or a kneader and then dissolved in a solvent is also effective for obtaining good dispersibility of the carbon black.
• carbon black may be forcibly dispersed in the resin in a solution state.
• the solvent for forming the infrared ablation layer such as a solution or a dispersion, can be appropriately selected in consideration of the solubility of the resin or carbon black used. Only one kind of solvent may be used, or two or more kinds of solvents may be mixed and used. Further, for example, mixing a low boiling point solvent and a high boiling point solvent to control the volatilization rate of the solvent is effective because (c) the film quality of the infrared ablation layer can be improved.
• the solvent for forming the infrared ablation layer is not limited to the following, but for example, toluene, xylene, cyclohexane, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, methyl ethyl ketone, acetone, cyclohexanone.
• Ethylglycol propylene glycol, ethanol, water, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dimethylacetamide, dimethylformamide, n-propyl alcohol, i-propyl alcohol, 1,4-dioxane, tetrahydrofuran, diethyl ether, n -Hexene, n-heptane, n-pentane, acetonitrile and its analogs and the like can be mentioned.
• a cover film can be used to form the (c) infrared ablation layer of the photosensitive resin composition for flexographic printing plates of the present embodiment.
• the cover film is preferably a film having excellent dimensional stability, and for example, a polyethylene terephthalate film or the like is preferable.
• a film to which functions such as mold release treatment and antistatic treatment may be added may be used, if necessary.
• a method for forming an infrared ablation layer using a cover film the method described in Examples described later can be applied.
• the following method is preferable.
• the first step of irradiating ultraviolet rays from the support side and (c) the infrared ablation layer are irradiated with infrared rays.
• a step of post-exposure treatment is performed to obtain a flexographic printing plate (toppan printing plate) made of a cured product of the photosensitive resin composition layer.
• the surface of the flexographic printing plate may be brought into contact with a liquid containing a silicone compound and / or a fluorine compound.
• the method for manufacturing the flexographic printing plate of the present embodiment is not limited to the above-mentioned method.
• the first to third steps can be appropriately rearranged or performed in parallel.
• the first step of irradiating ultraviolet rays from the support side (a) can be performed by using a conventional irradiation unit.
• ultraviolet rays ultraviolet rays having a wavelength of 150 to 500 nm can be used, and in particular, ultraviolet rays having a wavelength of 300 to 400 nm can be preferably used.
• the light source for example, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a zirconium lamp, a carbon arc lamp, a fluorescent lamp for ultraviolet rays and the like can be used.
• the first step of irradiating with ultraviolet rays may be performed before the second step of (c) drawing the pattern on the infrared ablation layer, or after the second step of drawing the pattern. good.
• the infrared ablation layer and the photosensitive resin composition layer are laminated to form a flexographic printing plate. Since the photosensitive resin composition is obtained, the layer structure of the photosensitive resin composition for the flexographic printing plate is a cover film / an infrared ablation layer / a photosensitive resin composition layer.
• the cover film is first peeled off before the drawing process. Then, (c) the infrared ablation layer is irradiated with infrared rays in a pattern, and (b) a mask is formed on the photosensitive resin composition layer.
• Suitable infrared lasers include, for example, ND / YAG lasers (eg, 1064 nm) or diode lasers (eg, 830 nm).
• a laser system suitable for the CTP plate making technique is commercially available, and for example, a diode laser system CDI Spark (ESKO GRAPHICS) can be used.
• the laser system includes a rotating cylindrical drum holding a photosensitive resin composition for a flexographic printing plate, an infrared laser irradiation device, and a layout computer, and image information is transmitted directly from the layout computer to the laser device.
• the photosensitive resin composition layer is entirely irradiated with ultraviolet rays via a mask.
• the irradiation of ultraviolet rays can be performed with the photosensitive resin composition for flexographic printing plate attached to the laser cylinder, but in general, the photosensitive resin composition for flexographic printing plate is removed from the laser device and is commonly used. This is done using an irradiation unit.
• the irradiation unit the same unit as that used for (a) ultraviolet irradiation from the support side can be used.
• a developing step is performed.
• a conventionally known method can be applied. Specifically, a method of developing by washing away the unexposed part with a solvent for solvent development or a cleaning liquid for water development, or a method of heating the unexposed part to 40 ° C. or higher and 200 ° C. or lower and heating the unexposed portion. Examples thereof include a method of developing by contacting a portion with an absorbable absorbing layer and removing the unexposed portion by absorbing and removing the unexposed portion by the absorbing layer (hereinafter referred to as thermal development). After that, a flexographic printing plate is manufactured by performing post-exposure processing as necessary.
• the developing solvent for developing by washing away the unexposed portion is not limited to the following, but for example, esters such as heptyl acetate and 3-methoxybutyl acetate; petroleum distillates, toluene and decalin.
• Hydrocarbons such as; and alcohols such as propanol, butanol, and pentanol mixed with a chlorine-based organic solvent such as tetrachloroethylene;
• the unexposed portion may be washed away by injecting a solvent from a nozzle, or brushing may be performed.
• an alkaline aqueous solution or a neutral aqueous solution can be used as the cleaning liquid for water development.
• a surfactant can be preferably used in the cleaning liquid for water development.
• the surfactant include anionic surfactants, amphoteric surfactants, nonionic surfactants and the like. These may be used alone or in admixture of two or more.
• the anionic surfactant is not limited to the following, but is not limited to, for example, sulfate ester salt, higher alcohol sulfate ester, higher alkyl ether sulfate ester salt, sulfated olefin, alkylbenzene sulfonate, ⁇ -olefin sulfonic acid.
• amphoteric tenside is not limited to the following, and examples thereof include amino acid type amphoteric tenside agents and betaine type amphoteric tenside agents.
• Nonionic surfactants are not limited to the following, but are not limited to, for example, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, and higher grades.
• polyethylene glycol-type surfactants such as alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol, and sorbitan fatty acid esters and polyhydric alcohols.
• polyhydric alcohol-type surfactants such as alkyl esters and fatty acid amides of alkanolamines.
• an alkaline aqueous solution may be prepared using a pH adjuster.
• the pH adjusting agent may be either an organic material or an inorganic material, but an agent capable of adjusting the pH to 9 or more is preferable.
• Examples of the pH adjuster include, but are not limited to, sodium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, sodium metasilicate, sodium amber and the like.
• the absorbent layer that absorbs the unexposed portion used in the thermal development is not limited to the following, but is, for example, a non-woven fabric material, a paper material, a fiber woven fabric, a fiber knitted fabric, an open cell foam, and the like. Porous materials can be mentioned.
• the preferred absorbent layer is a non-woven fabric material containing nylon, polyester, polypropylene or polyethylene, and a combination of these non-woven fabric materials.
• a particularly preferred absorbent layer is a nylon or polyester non-woven continuous web.
• HSPiP Hansen solubility parameter
• the Hansen solubility parameter was measured using the PC software HSPiP.
• HSP measurement of the resin in the infrared ablation layer acetone, 2-butanol, cyclohexanone, ethanol, ethyl acetate, hexane, butyl acetate, isobutyl acetate, MEK (methyl ethyl ketone), propylene glycol 1-monomethyl ether 2-acetate ( Using PMA), THF (tetratetra), toluene, and xylene, 10 g of each solvent was put into a 20 mL vial, and 0.1 g of the resin was mixed therein.
• the styrene content of resin was measured as follows. The measurement was carried out under the following conditions using a nuclear magnetic resonance apparatus ( 1 H-NMR) "JNM-LA400" (manufactured by JEOL). Deuterated chloroform was used as the solvent, and the resin concentration was adjusted to 50 mg / mL. Observation frequency: 400MHz, Chemical shift criteria: TMS (tetramethylsilane) Pulse delay: 2.904 seconds Number of scans: 64 times Pulse width 45 ° Measurement temperature: 26 ° C
• the photosensitive resin composition for a flexographic printing plate was cut to an appropriate size and then embedded in a resin using an ultraviolet curable resin. After embedding in the resin, the cross section prepared by the cryomicrotome method was used as an SEM observation sample.
• ⁇ Cross-section processing conditions Equipment used: Ultra Microtome UC6 (manufactured by LEICA) Set temperature: -80 ° C Set cutting thickness: 100 nm ⁇ SEM observation conditions> Measuring device: Scanning electron microscope S4800 (manufactured by Hitachi) Acceleration voltage: 1.0kV Observation magnification: 5000 times The length of the minor axis diameter of any 10 particle sizes of carbon black was measured from the obtained cross-sectional SEM observation image, and the average value (number average) was taken as the primary particle diameter of carbon black. ..
• DBP oil absorption of carbon black The amount of DBP oil absorbed by carbon black was measured by the method specified in JIS K6217-4.
• a photosensitive resin composition for a flexographic printing plate was produced.
• ((1) Manufacture of a laminate of a support and a photosensitive resin composition layer) 60 parts by mass of styrene-butadiene-styrene block copolymer (trade name: Toughprene A manufactured by Asahi Kasei), 30 parts by mass of liquid polybutadiene (trade name: B-2000 manufactured by Nippon Petrochemical), 1,9-nonanediol diacrylate 7
• a photosensitive resin composition was obtained by kneading a parts by mass, 2 parts by mass of 2,2-dimethoxy-2-phenylacetophenone and 0.3 parts by mass of 2,6-di-t-butyl-p-cresol with a pressure kneader.
• the photosensitive resin composition is put into an extrusion molding machine, and a base film (support) is attached to one surface of the photosensitive resin composition extruded from a T-shaped die to bond the photosensitive resin composition.
• a release film manufactured by Mitsubishi Chemical Corporation, trade name: Diafoil MRV100 was attached to the surface of the layer opposite to the support laminated side to obtain a laminated body of the support and the photosensitive resin composition layer.
• the carbon black dispersion is coated on a 100 ⁇ m-thick PET film to be a cover film so that the film thickness after drying is 10 ⁇ m, and dried at 90 ° C. for 2 minutes to cover the infrared ablation layer.
• An infrared ablation layer laminate 1 which is a laminate with a film was obtained. Table 1 below shows the constituent materials and physical properties of the infrared ablation layer laminate 1.
• infrared ablation layer laminates 2 to 21, 25, 26 are the same as the infrared ablation layer laminate 1 except that the resin used, the type of carbon black, and the blending ratio of each are changed as shown in Table 1 below.
• Got Table 1 below shows the constituent materials and physical properties.
• Infrared ablation which is a laminate of an infrared ablation layer and a cover film, is the same as in the production example of the infrared ablation layer laminate 23, except that carbon black is changed to carbon black (manufactured by Mitsubishi Chemical Corporation, trade name: MA100).
• a layered laminate 24 was obtained. Table 1 below shows the constituent materials and physical properties.
• Example 1 The photosensitive resin composition 1 for a flexographic printing plate produced as described above was evaluated as follows. The evaluation results are shown in Table 2 below. The evaluation was carried out by cutting out the photosensitive resin composition for a flexographic printing plate into a size of 10 cm ⁇ 15 cm and peeling off the cover film.
• the photosensitive resin composition 1 for a flexographic printing plate is installed in Esco CDI SPARK2530, and laser drawing is performed with a test image having an image pattern forming a total of 4 pixels of 2 ⁇ 2 pixels at a resolution of 4000 dpi and a laser intensity of 3.0 J. went. After that, the ablation part was observed using a laser microscope (trade name: VK-X100 manufactured by KEYENCE CORPORATION, objective lens 100 times), and the maximum depth cut by the laser was used as an index value of laser sensitivity, and according to the following criteria. evaluated.
• the photosensitive resin composition 1 for a flexographic printing plate is installed in a digital flexo imager (trade name: CDI SPARK2530 manufactured by Esko) to form a total of 4 pixels of 2 ⁇ 2 pixels at a resolution of 4000 dpi and a laser intensity of 5.0 J.
• a digital flexo imager (trade name: CDI SPARK2530 manufactured by Esko) to form a total of 4 pixels of 2 ⁇ 2 pixels at a resolution of 4000 dpi and a laser intensity of 5.0 J.
• Laser drawing was performed on a test image with an image pattern to be used. Then, the ablation part was observed using a laser microscope (VK-X100, manufactured by KEYENCE CORPORATION; objective lens 100 times).
• the length of the laser-cut portion on the surface of the infrared ablation layer and the length of the laser-cut portion at the interface with the photosensitive resin composition layer are measured, and the interface with the photosensitive resin composition layer / the surface of the infrared ablation layer.
• the ratio of the partial lengths cut by the laser was evaluated as follows as an index of the infrared ablation layer removability at the interface of the photosensitive resin composition layer.
• A The ratio of the length of the laser-cut portion on the surface of the interface / infrared ablation layer with the photosensitive resin composition is 0.55 or more.
• B Laser on the surface of the interface / infrared ablation layer with the photosensitive resin composition.
• the ratio of the length of the part cut by the laser is 0.50 or more and less than 0.55
• C The ratio of the length of the part cut by the laser on the surface of the interface / infrared ablation layer with the photosensitive resin composition is 0.45 or more.
• D Interface with photosensitive resin composition / Infrared ablation layer
• E Interface with the photosensitive resin composition /
• the ratio of the length of the laser-cut part on the surface of the infrared ablation layer is less than 0.40.
• the infrared ablation layer laminate 1 was laminated at a temperature of 120 ° C. so that the infrared ablation layer was in contact with the photosensitive resin composition layer to obtain a sample.
• the cover film of the infrared ablation layer After removing the cover film of the infrared ablation layer, it was placed on a light table and illuminated with a light table from under the sample, and it was determined that the part that appeared to shine was a pinhole.
• the number of pinholes having a major axis of 20 ⁇ m or more was counted, an average value was calculated, a value of (pieces / m 2 ) was calculated, and the evaluation was performed as follows.
• the infrared ablation layer laminate 1 is laminated in an environment of a temperature of 25 ° C. and a humidity of 40% so that the infrared ablation layer is in contact with the photosensitive resin composition layer, and is photosensitive for a flexographic printing plate.
• the sex resin composition 1 was obtained. It was evaluated whether the infrared ablation layer and the photosensitive resin composition layer were sufficiently adhered to each other only by the laminating, or whether they were sufficiently adhered to each other by further heating after the laminating.
• the photosensitive resin composition 1 for a flexographic printing plate was bent 90 ° so that the infrared ablation layer was inside, starting from the vicinity of the center. After that, it was bent 90 ° so that the support was inside. This operation was repeated three times, and it was observed whether or not the infrared ablation layer was peeled off from the photosensitive resin composition layer, and evaluated as follows.
• C Sufficient adhesion was obtained by further heating after laminating, and it did not peel off even when a bending test was performed.
• E Peeled by bending test.
• the photosensitive resin composition 1 for a flexographic printing plate was bent 180 ° so that the supports were inside, that is, in a state where the supports were in contact with each other, starting from the vicinity of the center. After that, it was observed whether wrinkles were generated on the surface of the infrared ablation layer, and evaluated as follows.
• C Multiple wrinkles were generated at the end of the photosensitive resin composition for flexographic printing plate.
• D Wrinkles were generated near the edges and the center of the photosensitive resin composition for flexographic printing plates.
• E Wrinkles were generated on the entire surface of the photosensitive resin composition for flexographic printing plates.
• Example 2 The photosensitive resin constituents 2 to 21 for flexographic printing plates were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 2 below.
• the photosensitive resin composition for a flexographic printing plate of the present invention has industrial applicability in a wide range of general commercial printing fields.

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