JP5481794B2 - Method for producing molded product for laser processing, molded product for laser processing, and flexographic printing plate - Google Patents

Description

  The present invention relates to a method for producing a molded article for laser processing excellent in engraving by laser, a molded article for laser processing produced by the production method, and a flexographic printing plate.

  As a method for producing a printing plate by forming irregularities on the surface of a polymer material, a method of engraving a vulcanized rubber sheet with a stamp is common. However, this method of engraving with a sword requires advanced hand-carving techniques. Therefore, in addition to skill, there is a limit to engraving fine and complicated characters and figures. Furthermore, when producing a flexographic printing plate, it is necessary to accurately position each part produced by hand engraving on a resin sheet such as PET and affix it with an adhesive. For this reason, there is a problem that it takes time and effort.

  On the other hand, a method of engraving a desired shape or the like by irradiating a laser on a printing material made of a resin material using a laser processing machine has been developed recently. As related prior art, polymer materials for laser processing obtained by crosslinking an ethylene-based polymer or copolymer, and laminates for laser processing using the same are disclosed (for example, see Patent Documents 1 and 2). ). Also disclosed is a laser processing sheet produced by using a laser processing composition containing a predetermined amount of thermoplastic elastomer such as syndiotactic 1,2-polybutadiene and silica particles (for example, Patent Documents). 3).

  Also disclosed are flexographic printing elements having at least one laser-engravable elastomeric layer in which an elastomeric material such as a SIS (styrene-isoprene-styrene) block copolymer is reinforced with a crosslinking agent (e.g. 5).

Japanese Patent Laid-Open No. 2002-3665 JP 2002-103539 A JP 2006-206872 A Japanese Patent No. 2846954 Japanese Patent No. 2846955

  However, even the laser processing sheet disclosed in the above-mentioned patent document is still not at a sufficient level in terms of workability and transparency, and there is room for further improvement. Further, since the edge portion is easily melted by heat at the time of laser processing and the engraving property (pattern forming property) may be insufficient, there is a need for further improvement.

  The present invention has been made in view of such problems of the prior art, and the problem is that it is flexible, has good workability and transparency, and is engraved by laser. Another object of the present invention is to provide a method for producing a molded product for laser processing, which can easily produce a molded product for laser processing excellent in the above.

  Moreover, the place made into the subject of this invention is providing the molded article for laser processing which has the favorable softness | flexibility and transparency, and was excellent in the engraving property by a laser. Furthermore, an object of the present invention is to provide a flexographic printing plate having a printing pattern engraved with a laser easily and with high accuracy.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors prepared a crosslinkable composition containing a thermoplastic polymer and a specific cross-linking agent, and a part of this composition was thermally cross-linked dynamically. After that, it was found that the above problem can be achieved by further radiation crosslinking, and the present invention has been completed.

  That is, according to this invention, the manufacturing method of the molded article for laser processing shown below, the molded article for laser processing, and a flexographic printing plate are provided.

[1] (A) Syndiotactic 1,2-polybutadiene having a 1,2-vinyl bond content of 70% or more and a crystallinity of 5 to 50%, a styrene / isoprene copolymer, and a styrene / butadiene copolymer 100 parts by mass of a thermoplastic polymer that is at least one selected from the group consisting of a coalescence, (B) 0 to 50 parts by mass of silica particles, and (C) a viscosity specific gravity constant (VGC value) of 0. Including 0 to 200 parts by weight of an extending oil that is 790 to 0.999, (D) 0 to 10 parts by weight of a photopolymerization initiator, and (E) 0 to 20 parts by weight of a polyfunctional acrylate , after the oxide 0.01 parts by weight or crosslinking composition comprising (G) sulfur or a sulfur compound 0.01 to 1.0 parts by weight, and dynamically heat crosslinking, further radiation crosslinking Of manufacturing molded article for laser processing including

[ 2 ] The method for producing a molded article for laser processing according to [1 ], wherein the (B) silica particles are anhydrous particles having an average primary particle diameter of 0.005 μm or more and less than 0.1 μm.

[ 3 ] The method for producing a molded article for laser processing according to [1] or [2] , wherein (C) the extending oil is at least one of a paraffinic extending oil and a naphthenic extending oil.

[ 4 ] The method for producing a molded article for laser processing according to any one of [1] to [ 3 ], wherein the (D) photopolymerization initiator is an acylphosphine oxide compound.

[ 5 ] Production of a molded article for laser processing according to any one of [1] to [ 4 ], wherein the (E) polyfunctional acrylate is at least one of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate. Method.

[ 6 ] The laser according to any one of [1] to [ 5 ], wherein the organic peroxide (F) has a half-life of 1 minute at a temperature of 90 ° C or higher and lower than 180 ° C. A method for manufacturing a molded article for processing.

[ 7 ] The method for producing a molded article for laser processing according to any one of [1] to [ 6 ], wherein the radiation used for the radiation crosslinking is an ultraviolet ray or an electron beam.

[ 8 ] A sheet-shaped molded article having a machined surface capable of laser engraving on at least one surface, produced by the method for producing a molded article for laser processing according to any one of [1] to [ 7 ]. Molded product for laser processing.

[ 9 ] The molded product for laser processing according to [ 8 ], wherein a sheet-like base material layer is laminated on one surface.

[10] A flexographic printing plate in which the processed surface of the molded article for laser processing according to [8] or [9] is engraved with a laser to form a predetermined printing pattern.
[11] A crosslinkable composition used in the method for producing a molded article for laser processing according to any one of [1] to [7], wherein (A) a 1,2-vinyl bond content is 70% or more, a crystal 100 parts by mass of a thermoplastic polymer that is at least one selected from the group consisting of syndiotactic 1,2-polybutadiene, styrene / isoprene copolymer, and styrene / butadiene copolymer having a degree of conversion of 5 to 50% (B) 0 to 50 parts by mass of silica particles, (C) 0 to 200 parts by mass of an extension oil having a viscosity specific gravity constant (VGC value) of 0.790 to 0.999, and (D) light. 0-10 parts by weight polymerization initiator, and includes (E) a polyfunctional acrylate 0-20 parts by weight, further, (F) an organic peroxide 0.01 to 0.1 parts by weight or (G) sulfur or a sulfur Crosslinkable group containing 0.01 to 1.0 part by mass of compound Adult.

  According to the method for producing a molded article for laser processing of the present invention, it is possible to easily produce a molded article for laser machining that is flexible, has good processability and transparency, and has excellent engraving properties by laser. Can do.

  The molded article for laser processing according to the present invention has excellent flexibility and transparency, and has an effect of being excellent in engraving by a laser. Further, the flexographic printing plate of the present invention has an effect of having a printing pattern engraved easily and with high precision by a laser.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. Molded product for laser processing and manufacturing method thereof:
The method for producing a molded article for laser processing according to the present invention comprises (A) 100 parts by mass of a thermoplastic polymer, (B) 0 to 50 parts by mass of silica particles, and (C) a viscosity specific gravity constant (VGC value). ) Is 0.790-0.999 parts of extended oil 0-200 parts by weight, (D) photopolymerization initiator 0-10 parts by weight, (E) polyfunctional acrylate 0-20 parts by weight, and (F) organic Radiation after further thermally cross-linking a crosslinkable composition containing 0.01 to 0.1 part by mass of a peroxide or 0.01 to 1.0 part by mass of (G) sulfur or a sulfur compound, and further radiation. It is a manufacturing method including bridge | crosslinking. The details will be described below.

(A) Thermoplastic polymer The crosslinkable composition includes (A) a thermoplastic polymer (hereinafter also referred to as “component (A)”). Preferred examples of the component (A) include (A-1) syndiotactic 1,2-polybutadiene, (A-2) styrene / isoprene copolymer, and (A-3) styrene / butadiene copolymer. Can be mentioned. In addition, these thermoplastic polymers can be used individually by 1 type or in combination of 2 or more types.

(A-1) Syndiotactic 1,2-polybutadiene The 1,2-vinyl bond content of the syndiotactic 1,2-polybutadiene is preferably 70% or more, more preferably 80% or more, 90% or more is particularly preferable. By setting the 1,2-vinyl bond content of the syndiotactic 1,2-polybutadiene to 70% or more, the properties as a thermoplastic elastomer including flexibility are exhibited well. The “1,2-vinyl bond content” referred to in the present specification is a value determined by an infrared absorption spectrum method (Morello method).

The crystallinity of the syndiotactic 1,2-polybutadiene is preferably 5 to 50%, and more preferably 10 to 40%. Further, the melting point (Tm) of syndiotactic 1,2-polybutadiene is preferably 50 to 150 ° C, and more preferably 60 to 140 ° C. By using syndiotactic 1,2-polybutadiene whose crystallinity and melting point are within these ranges, it is possible to produce molded products for laser processing that have a good balance between mechanical strength such as tensile strength and tear strength and flexibility. can do. As used herein, “crystallinity” refers to the density of 1,2-polybutadiene having a crystallinity of 0% of 0.889 g / cm ³ and the density of 1,2-polybutadiene having a crystallinity of 100% of 0. .963 g / cm ³ is a value converted from the density measured by the underwater substitution method.

  The weight average molecular weight (Mw) of syndiotactic 1,2-polybutadiene is preferably 10,000 to 5,000,000, more preferably 10,000 to 1,500,000, and particularly preferably 50,000 to 1,000,000. preferable. If the Mw is less than 10,000, the fluidity becomes too high and the processing becomes difficult, and the resulting molded product for laser processing tends to be sticky. On the other hand, when Mw exceeds 5 million, the fluidity tends to be too low and the processing tends to be difficult.

  The syndiotactic 1,2-polybutadiene may be obtained by copolymerizing a small amount of a conjugated diene other than butadiene. Examples of conjugated dienes other than butadiene include 1,3-pentadiene, 1,3-butadiene derivatives substituted with higher alkyl groups, and 2-alkyl substituted-1,3-butadiene. Specific examples of 1,3-butadiene derivatives substituted with a higher alkyl group include 1-pentyl-1,3-butadiene, 1-hexyl-1,3-butadiene, 1-heptyl-1,3-butadiene, 1 -Octyl-1,3-butadiene and the like can be mentioned.

  Specific examples of 2-alkyl-substituted-1,3-butadiene include 2-methyl-1,3-butadiene (isoprene), 2-ethyl-1,3-butadiene, 2-propyl-1,3-butadiene, 2 -Isopropyl-1,3-butadiene, 2-butyl-1,3-butadiene, 2-isobutyl-1,3-butadiene, 2-amyl-1,3-butadiene, 2-isoamyl-1,3-butadiene, 2 -Hexyl-1,3-butadiene, 2-cyclohexyl-1,3-butadiene, 2-isohexyl-1,3-butadiene, 2-heptyl-1,3-butadiene, 2-isoheptyl-1,3-butadiene, 2 -Octyl-1,3-butadiene, 2-isooctyl-1,3-butadiene and the like can be mentioned.

  Of these conjugated dienes other than butadiene, isoprene and 1,3-pentadiene are preferred. The content of butadiene in the monomer component to be polymerized is preferably 50 mol% or more, and more preferably 70 mol% or more.

  Syndiotactic 1,2-polybutadiene can be obtained, for example, by polymerizing butadiene in the presence of a catalyst containing a cobalt compound and an aluminoxane. As a cobalt compound, Preferably, the organic acid salt of C4 or more organic acid and cobalt can be mentioned. Specific examples of organic acid salts include butyrate, hexanoate, heptylate, octylate such as 2-ethylhexylic acid, decanoate, higher fatty acid salts such as stearic acid, oleic acid, erucic acid, benzoic acid, etc. Examples thereof include alkyl, aralkyl, allyl-substituted benzoate, naphthoate, alkyl, aralkyl, and allyl-substituted naphthoate such as acid salt, tolylate, xylate, and ethylbenzoate. Of these, so-called octylates such as 2-ethylhexylic acid, stearates, and benzoates are preferable because they have excellent solubility in hydrocarbon solvents.

  As an aluminoxane, what is represented by the following general formula (1) or (2) can be mentioned, for example.

  In the general formulas (1) and (2), R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group, or a butyl group, preferably a methyl group or an ethyl group, and particularly preferably a methyl group. . M is an integer of 2 or more, preferably 5 or more, more preferably 10 to 100. Specific examples of aluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane and the like. Of these, methylaluminoxane is preferable.

It is extremely preferable that the polymerization catalyst contains a phosphine compound in addition to the cobalt compound and the aluminoxane. The phosphine compound is an effective component for activating the polymerization catalyst, controlling the vinyl bond structure and crystallinity. Suitable phosphine compounds include organophosphorus compounds represented by the following general formula (3).
P (Ar) _n (R ′) _3-n (3)

  In the general formula (3), R ′ is a cycloalkyl group or an alkyl-substituted cycloalkyl group, n is an integer of 0 to 3, and Ar is a group represented by the following general formula (4).

In the general formula (4), R ¹ , R ² , and R ³ may be the same or different and are a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group, or an aryl group. As the alkyl group represented by R ¹ , R ² , and R ³ , an alkyl group having 1 to 6 carbon atoms is preferable. ^As the alkoxy group represented by R 1, ^{R 2,} and ^{R 3,} preferably an alkoxy group having 1 to 6 carbon atoms. Furthermore, the aryl group represented by R ¹ , R ² , and R ³ is preferably an aryl group having 6 to 12 carbon atoms.

  Specific examples of the phosphine compound represented by the general formula (3) include tris (3-methylphenyl) phosphine, tris (3-ethylphenyl) phosphine, tris (3,5-dimethylphenyl) phosphine, tris (3 , 4-Dimethylphenyl) phosphine, Tris (3-isopropylphenyl) phosphine, Tris (3-t-butylphenyl) phosphine, Tris (3,5-diethylphenyl) phosphine, Tris (3-methyl-5-ethylphenyl) Phosphine), tris (3-phenylphenyl) phosphine, tris (3,4,5-trimethylphenyl) phosphine, tris (4-methoxy-3,5-dimethylphenyl) phosphine, tris (4-ethoxy-3,5- Diethylphenyl) phosphine, tris (4-butoxy-3,5- Butylphenyl) phosphine, tri (p- methoxyphenyl) phosphine, tricyclohexylphosphine, dicyclohexylphenylphosphine, tribenzylphosphine, tri (4-methylphenyl) phosphine, tri (4-ethylphenyl) phosphine and the like. Of these, triphenylphosphine, tris (3-methylphenyl) phosphine, tris (4-methoxy-3,5-dimethylphenyl) phosphine and the like are particularly preferable.

  As the cobalt compound, a compound represented by the following general formula (5) can be used.

  The compound represented by the general formula (5) is a complex having a phosphine compound in which n is 3 in the general formula (3) as a ligand with respect to cobalt chloride. In using this cobalt compound, a pre-synthesized one may be used, or a method in which cobalt chloride and a phosphine compound are brought into contact with each other in the polymerization system. By selecting various phosphine compounds in the complex, the 1,2-bond content and crystallinity of the resulting syndiotactic 1,2-polybutadiene can be controlled.

  Specific examples of the cobalt compound represented by the general formula (5) include cobalt bis (triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3-ethylphenyl). Phosphine)] dichloride, cobalt bis [tris (4-methylphenylphosphine)] dichloride, cobalt bis [tris (3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (3,4-dimethylphenylphosphine)] dichloride , Cobalt bis [tris (3-isopropylphenylphosphine)] dichloride, cobalt bis [tris (3-t-butylphenylphosphine)] dichloride, cobalt bis [tris (3,5-diethylphenylphosphine) Dichloride, cobalt bis [tris (3-methyl-5-ethylphenylphosphine)] dichloride, cobalt bis [tris (3-phenylphenylphosphine)] dichloride, cobalt bis [tris (3,4,5-trimethylphenylphosphine)] Dichloride, cobalt bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride, cobalt bis [tris (4-ethoxy-3,5-diethylphenylphosphine)] dichloride, cobalt bis [tris (4-butoxy -3,5-dibutylphenylphosphine)] dichloride, cobalt bis [tris (4-methoxyphenylphosphine)] dichloride, cobalt bis [tris (3-methoxyphenylphosphine)] dichloride, cobalt bis [to Scan (4-dodecylphenyl) phosphine] dichloride, cobalt bis [tris (4-ethylphenyl) phosphine] dichloride, and the like.

  Among these, cobalt bis [triphenylphosphine) dichloride, cobalt bis [tris (3-methylphenylphosphine)] dichloride, cobalt bis [tris (3,5-dimethylphenylphosphine)] dichloride, cobalt are particularly preferable. Bis [tris (4-methoxy-3,5-dimethylphenylphosphine)] dichloride and the like can be mentioned.

In the case of butadiene homopolymerization, a cobalt compound is used as a catalyst in an amount of 0.001 to 1 mmol in terms of cobalt atom per mol of butadiene, or in the case of copolymerization, per mol of the total amount of butadiene and conjugated diene other than butadiene. It is preferable to use 0.01 to 0.5 mmol. Moreover, the usage-amount of a phosphine compound is 0.1-50 normally as a ratio (P / Co) of the phosphorus atom with respect to a cobalt atom, it is preferable that it is 0.5-20, and it is 1-20. Further preferred. Furthermore, the usage-amount of aluminoxane is 4-10 < ⁷ > normally as a ratio (Al / Co) of the aluminum atom with respect to the cobalt atom of a cobalt compound, and it is preferable that it is 10-10 < ⁶ >. In addition, when using the complex represented by the said General formula (5), the usage-amount of a phosphine compound assumes that the ratio (P / Co) of the phosphorus atom with respect to a cobalt atom is 2, and the usage-amount of aluminoxane is as follows. Follow the above description.

  Examples of the inert organic solvent used as the polymerization solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene and cumene, aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-butane, and cyclopentane. , Alicyclic hydrocarbon solvents such as methylcyclopentane and cyclohexane, and mixtures thereof.

  The polymerization temperature is usually −50 to 120 ° C., preferably −20 to 100 ° C. The polymerization reaction may be batch or continuous. In addition, the monomer density | concentration in a solvent is 5-50 mass% normally, Preferably it is 10-35 mass%. In addition, in order to prevent the catalyst and the polymer from being deactivated in order to produce the polymer, it is necessary to consider that the mixing of compounds having a deactivating action such as oxygen, water, or carbon dioxide gas is minimized in the polymerization system. It is. When the polymerization reaction proceeds to a desired stage, the reaction mixture is added with alcohol, other polymerization terminator, anti-aging agent, antioxidant, ultraviolet absorber, etc., and then the produced polymer is separated and washed according to the usual method. If dried, syndiotactic 1,2-polybutadiene can be obtained.

(A-2) Styrene / isoprene copolymer The molecular weight of the styrene / isoprene copolymer (SIS) is not particularly limited, but the weight average molecular weight (Mw) is preferably 10,000 to 5,000,000, and preferably 10,000 to 150. Even more preferred is. Examples of commercially available SIS products include SIS5200P and SIS5229P (both are trade names) manufactured by JSR Corporation, and Quintac 3433 (trade name) manufactured by Nippon Zeon Co., Ltd.

(A-3) Styrene-butadiene copolymer The molecular weight of the styrene-butadiene copolymer (SBS) is not particularly limited, but preferably has a weight average molecular weight (Mw) of 10,000 to 5,000,000, preferably 10,000 to 150. Even more preferred is. Examples of commercially available products of SBS include TR1600, TR2000, TR2827 (all trade names) manufactured by JSR Corporation, Tufplen 125, Tufprene 126 (all trade names) manufactured by Asahi Kasei Chemicals Corporation, and the like.

  When (A-1) syndiotactic 1,2-polybutadiene is used in combination with (A-2) at least one of styrene / isoprene copolymer and (A-3) styrene / butadiene copolymer Is preferable in order to improve the flexibility of the obtained molded article for laser processing. When (A-1) syndiotactic 1,2-polybutadiene is used in combination with at least one of (A-2) a styrene / isoprene copolymer and (A-3) a styrene / butadiene copolymer. (A-1): {(A-2) + (A-3)} is a mass ratio of preferably 80:20 to 20:80, and 70:30 to 30:70. Is more preferable. By defining (A-1): {(A-2) + (A-3)} within this range, it is possible to produce a molded article for laser processing that is more excellent in flexibility and workability.

(B) Silica Particles It is preferable for the crosslinkable composition to contain (B) silica particles (hereinafter also referred to as “component (B)”). By containing the component (B), it is possible to produce a molded article for laser processing that is excellent in workability and does not have a residue after laser processing. The content of the component (B) is preferably 0 to 50 parts by mass, more preferably 0.1 to 50 parts by mass, and 1 to 45 parts by mass with respect to 100 parts by mass of the component (A). Particularly preferred is 5 to 40 parts by mass. When the content of the component (B) is more than 50 parts by mass with respect to 100 parts by mass of the component (A), the flexibility and workability of the manufactured molded product for laser processing tend to be impaired.

  As silica particles, various types can be mentioned. From the viewpoint of further suppressing the flame generated during laser processing and further suppressing the stickiness of the processed surface to improve the laser engraving accuracy, anhydrous silica particles. Is preferred. The average primary particle diameter of the silica particles is preferably 0.005 μm or more and less than 0.1 μm, more preferably 0.01 or more and less than 0.1 μm, and preferably 0.01 to 0.05 μm. It is particularly preferred. When the average primary particle diameter of the silica particles is 0.1 μm or more, the laser engraving accuracy tends to be inferior. On the other hand, when it is less than 0.005 μm, it tends to be substantially difficult to obtain. In addition, as a more specific example of suitable silica particles contained in the composition for laser processing of the present embodiment, Aerosil (trade name (manufactured by Degussa)) and the like can be mentioned. In addition, a silica particle can be used individually by 1 type or in combination of 2 or more types.

(C) Extending oil The crosslinkable composition has a viscosity specific gravity constant (also referred to as “viscosity specific gravity constant”, hereinafter referred to as “VGC”) of 0.790 to 0.999, preferably It is preferable to contain (C) extended oil (hereinafter also referred to as “component (C)”) of 0.790 to 0.949, more preferably 0.790 to 0.912. By including the component (C), flexibility and workability can be improved. Specific examples of the component (C) include an aromatic extending oil, a naphthenic extending oil, and a paraffin extending oil. Of these, naphthenic extender oil and paraffinic extender oil are preferable, and it is also preferable to use naphthenic extender oil and paraffinic extender oil in combination.

  V. above. G. C. Specific examples of aromatic extender oils satisfying the numerical range of “Diana Process Oil AC-12”, “AC460”, “AH-16”, “AH-58” (above, Idemitsu Kosan Co., Ltd.) Product names “Mobil Sol K”, “Same 22”, “Same 130” (exxon Mobil Corp.); Product names “Kyoishi Process X50”, “X100”, “X140” (above) Trade names “Rezox No. 3”, “Dutrex 729UK” (above, manufactured by Shell Chemical Co., Ltd.); trade names “Komolex 200”, “300”, “500”, “ 700 ”(above, manufactured by Nippon Oil Co., Ltd.); Trade names“ Esso Process Oil 110 ”,“ 120 ”(above, ExxonMobil Corp.); Trade names“ Mitsubishi 34 Heavy Process Oil ”,“ Mitsubishi 44 Heavy Pro ” Scan oil "," Mitsubishi 38 heavy process oil "," Mitsubishi 39 heavy process oil "(above, Mitsubishi Oil Co., Ltd.); and the like can be given.

  In addition, V. G. C. Specific examples of naphthenic extender oils satisfying the numerical value ranges of “Diana Process Oil NS-24”, “NS-100”, “NM-26”, “NM-280”, “NP” -2 "(above, manufactured by Idemitsu Kosan Co., Ltd.); trade name" Naplex 38 "(above, manufactured by ExxonMobil Corp.); trade names" Fukkor FLEX # 1060N "," same # 1150N "," same # 1400N "," # 2040N "," # 2050N "(Fuji Kosan Co., Ltd.); trade names" Kyoishi Process R25 "," R50 "," R200 "," R1000 "(Nippon Kyoishi Co., Ltd.) Product names “Shelf Rex 371JY”, “Same 371N”, “Same 451”, “Same N-40”, “Same 22”, “Same 22R”, “Same 32R”, “Same 100R”, “Same 100S” ", 100 SA" “Same 220RS”, “Same 220S”, “Same 260”, “Same 320R”, “Same 680” (above, manufactured by Shell Chemical Co., Ltd.); ); Trade names “Esso Process Oil L-2”, “same 765” (exxon Mobil, Inc.); trade names “Mitsubishi 20 Light Process Oil” (ex, Mitsubishi Petroleum); .

  Furthermore, V. G. C. Specific examples of the paraffinic extender oil satisfying the numerical value range of “Diana Process Oil PW-90”, “PW-380”, “PS-32”, “PS-90”, “PS” -430 "(manufactured by Idemitsu Kosan Co., Ltd.); trade names" Fukkor Process P-100 "," P-200 "," P-300 "," P400 "," P-500 "(and above) Product names “Kyoishi Process P-200”, “P-300”, “P-500”, “Kyoishi EPT750”, “1000”, “Kyoishi Process S90” As above, trade names “Lebrex 26”, “100”, “460” (above, manufactured by Shell Chemical); trade names “Esso Process Oil 815”, “845”, “ B-1 ”,“ Naplex 32 ”(exxonmo Building Co., Ltd.); trade name "Mitsubishi 10 light process oil" (above, Mitsubishi Oil Co., Ltd.); and the like can be given.

  The content of the component (C) is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, and particularly preferably 100 parts by mass or less, with respect to 100 parts by mass of the component (A). preferable. When the content of the component (C) is more than 200 parts by mass with respect to 100 parts by mass of the component (A), the processability of the manufactured molded product for laser processing tends to be impaired. In addition, from the viewpoint that a flexographic printing plate having sufficient engraving accuracy can be provided with less stickiness on the processed surface, the content of the component (C) is 5 with respect to 100 parts by mass of the component (A). It is preferable that it is more than a mass part.

(D) Photopolymerization initiator The crosslinkable composition preferably contains (D) a photopolymerization initiator (hereinafter also referred to as “component (D)”). (D) By containing a component, it can bridge | crosslink with the ultraviolet-ray of a low energy dose. Although there is no restriction | limiting in particular in the kind of (D) component, As a specific example, a benzophenone, a benzyl dimethyl ketal, (alpha) -hydroxy ketones, (alpha) -amino ketones, oxime esters, and an acyl phosphine oxide type compound can be mentioned. Of these, α-hydroxyketones, α-aminoketones, and acylphosphine oxide compounds are preferable, and acylphosphine oxide compounds are particularly preferable. These photoinitiators can be used individually by 1 type or in combination of 2 or more types.

  Examples of the α-hydroxy ketones include 1-hydroxy-cyclohexyl-phenyl ketone and 2-hydroxy-2-methyl-1-phenyl-propan-1-one. As α-amino ketones, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone- 1 etc. can be mentioned. Examples of oxime esters include 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], and the like.

  Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide.

  The content of the component (D) is preferably 10 parts by mass or less, more preferably 0.1 to 10 parts by mass, and 0.1 to 7 parts by mass with respect to 100 parts by mass of the component (A). Part is particularly preferred. When the content of the component (D) is more than 10 parts by mass with respect to 100 parts by mass of the component (A), there is a tendency to bleed on the surface of the manufactured molded article for laser processing. In addition, since content of (D) component is less than 0.1 mass part with respect to 100 mass parts of (A) component, since crosslinking promotion effect is not fully acquired with the low energy dose of ultraviolet rays, radiation When the crosslinking is ultraviolet crosslinking, the engraving accuracy may be inferior.

(E) Polyfunctional acrylate The crosslinkable composition preferably contains (E) a polyfunctional acrylate (hereinafter also referred to as “component (E)”). By including the component (E), the crosslinking efficiency by radiation crosslinking can be improved, and the engraving accuracy of the manufactured product for laser processing can be improved.

  (E) Although there is no restriction | limiting in particular in the kind of component, As a specific example, a trimethylol propane triacrylate, a trimethylol propane trimethacrylate, a trimethylol propane trioxyethyl methacrylate, a pentaerythritol trimetallate, ethylene glycol dimethacrylate, a trimethylol Ethylene glycol diacrylate, tetraethylene glycol dimethacrylate, tricyclodecanediyl dimethanol dimethacrylate, polyethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, tri Examples include propylene glycol dimethacrylate and neopentyl glycol dimethacrylate. Among these, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropane trioxyethyl methacrylate, pentaerythritol trimethacrylate, ethylene glycol dimethacrylate, and triethylene glycol diacrylate are preferable, and trimethylolpropane triacrylate and trimethylolpropane are preferred. Trimethacrylate is particularly preferred. These polyfunctional acrylates can be used singly or in combination of two or more.

  The content of the component (D) is preferably 10 parts by mass or less, more preferably 0.1 to 7 parts by mass, and 0.1 to 4 parts by mass with respect to 100 parts by mass of the component (A). Part is particularly preferred. When the content of the component (D) is more than 10 parts by mass with respect to 100 parts by mass of the component (A), there is a tendency to bleed on the surface of the manufactured molded article for laser processing. If the content of component (D) is less than 0.1 parts by mass with respect to 100 parts by mass of component (A), the effect of promoting crosslinking cannot be sufficiently obtained. In some cases, the engraving accuracy may be inferior.

(F) Organic peroxide The crosslinkable composition preferably contains (F) an organic peroxide (hereinafter also referred to as “component (F)”). This component (F) is a component that acts as a crosslinking agent, and specific examples thereof include those commonly used as elastomer crosslinking agents. In addition, an organic peroxide can be used individually by 1 type or in combination of 2 or more types.

  When the component (F) is contained in the crosslinkable composition, the content of the component (F) is preferably 0.01 to 0.1 parts by mass with respect to 100 parts by mass of the component (A). The amount is more preferably 0.01 to 0.05 parts by mass, and particularly preferably 0.01 to 0.03 parts by mass. When the content of (F) is less than 0.01 parts by mass, the crosslinking reactivity is low, the crosslinking density of the obtained molded article for laser processing is low, and there is a tendency that suitable engraving accuracy is not exhibited. On the other hand, when the content of (F) is more than 0.1 parts by mass, it is difficult to control the crosslinking in a stable state, and the processability tends to deteriorate.

  The component (F) preferably has a temperature at which its half-life is 1 minute, 90 ° C. or more and less than 180 ° C. When such a component (F) is used, dynamic thermal cross-linking is possible, and even when the combined cross-linking radiation is a low energy dose, a high cross-linking density is obtained, and the laser processing to be manufactured is improved. The engraving accuracy of the molded product can be improved. Specific examples of such component (F) include 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1-bis (t-butylperoxy) cyclododecane, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butyl Peroxylaurate, 2,5-dimethyl-2,5-di (m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate, t-hexylper Oxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butyl Luperoxyacetate, 2,2-bis (t-butylperoxy) butane, t-butylperoxybenzoate, n-butyl-4,4-bis (t-butylperoxy) valerate, di-t-butylperoxy Isophthalate, α, α'-bis (t-butylperoxy) diisopropylbenzene, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide , Di-t-butyl peroxide, p-menthane hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3, diisopropylbenzene hydroperoxide, t-butyltrimethylsilyl peroxide 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydro Over oxide, t-hexyl hydroperoxide, may be mentioned t-butyl hydroperoxide and the like.

(G) Sulfur / sulfur compound The crosslinkable composition preferably contains (G) sulfur or a sulfur compound (hereinafter also referred to as “component (G)”). This (G) component is a component which acts as a crosslinking agent. When the component (G) is contained in the crosslinkable composition, the content of the component (G) is preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the component (A). It is more preferable that it is -0.5 mass part, and it is especially preferable that it is 0.01-0.3 mass part. When the content of (G) is less than 0.01 parts by mass, the crosslinking reactivity is low, the crosslinking density of the obtained molded article for laser processing is low, and there is a tendency that a suitable engraving accuracy is not exhibited. On the other hand, when the content of (G) is more than 1 part by mass, it is difficult to control crosslinking in a stable state, and the processability tends to deteriorate.

  Specific examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur. Two or more kinds of sulfur can be used in combination. Specific examples of the sulfur compound include thiuram compounds such as tetramethyl thiuram monosulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, dipentamethylene thiuram tetrasulfide; thiazole compounds and the like. it can. Two or more sulfur compounds may be used in combination.

(Other ingredients)
If necessary, the crosslinkable composition may contain a crosslinking aid, an activator, a flame retardant, an antiaging agent, a pigment, a liquid rubber, other polymers, and the like.

(Dynamic thermal crosslinking)
In the method for producing a molded article for laser processing of the present invention, the crosslinkable composition is first dynamically heat-treated and crosslinked (dynamic thermal crosslinking). Here, “dynamically heat-treating” refers to both applying a shearing force and heating. Since the crosslinkable composition contains the component (F) or the component (G) together with the component (A), the polymer component including the component (A) is crosslinked by dynamic heat treatment. The However, since the blending amount of the component (F) or the component (G) is set to be small relative to the blending amount of the component (A), only a part of the component (A) is crosslinked by this dynamic heat treatment. As a result, a partially cross-linked product having a certain degree of fluidity can be obtained.

  The presence or absence of crosslinking of the component (A) by dynamic heat treatment can be confirmed by GPC analysis as to whether or not a crosslinked polymer has been formed after heat treatment. This GPC analysis method will be described later.

  As an apparatus for carrying out dynamic thermal crosslinking, a melt kneading apparatus or the like can be cited as a suitable example. The treatment by the melt kneader may be either a continuous type or a batch type. Specific examples of the melt kneader include an open type mixing roll, a non-open type Banbury mixer, a single screw extruder, a twin screw extruder, a continuous kneader, and a pressure kneader. Further, two or more continuous melt-kneading apparatuses of the same type or different types may be used in combination.

  The treatment temperature for carrying out dynamic thermal crosslinking is preferably 90 to 180 ° C, more preferably 120 to 150 ° C. The treatment time is preferably 10 seconds to 30 minutes, more preferably 20 seconds to 20 minutes. Further, the shearing force to be applied is preferably 10 to 20000 / second in terms of shear rate, and more preferably 100 to 10,000 / second.

(Radiation crosslinking)
In the method for producing a molded article for laser processing according to the present invention, radiation crosslinking is carried out following dynamic thermal crosslinking. That is, radiation crosslinking is performed on the partially crosslinked product obtained by the above-described dynamic thermal crosslinking. By this radiation cross-linking, when laser processing is performed, a peripheral portion (a portion to be left) that is not engraved on the processed surface is hardly melted, and a molded product for laser processing capable of forming a print pattern with high engraving accuracy can be obtained. . In addition, the molded product for laser processing of a desired shape can be manufactured by shape | molding before radiation bridge | crosslinking.

  When the molded product for laser processing is a sheet-shaped molded product (laser processing sheet) having a processed surface capable of laser engraving on at least one surface, a partially crosslinked product obtained by dynamic thermal crosslinking Can be formed into a desired sheet shape by extrusion molding, calendar molding, press molding or the like. In addition, when manufacturing the sheet | seat for laser processing by extrusion molding, it is also possible to carry out radiation bridge | crosslinking continuously after extrusion molding, and it is preferable from a viewpoint of manufacturing efficiency.

  When EB crosslinking is performed, the electron beam irradiation (absorption) dose is preferably 20 to 500 kGy, and more preferably 50 to 200 kGy. If the electron beam irradiation (absorption) dose is less than 20 kGy, crosslinking may be insufficient. On the other hand, when the irradiation (absorption) dose of the electron beam exceeds 500 kGy, the obtained molded article for laser processing tends to be hard and the flexibility tends to be insufficient. The acceleration voltage of the electron beam is preferably 800 kV or less. If the acceleration voltage of the electron beam exceeds 800 kV, the electron beam irradiation apparatus becomes very expensive and tends to lack practicality.

On the other hand, when UV crosslinking is performed, the wavelength of ultraviolet rays to be irradiated is preferably in the range of 100 to 500 nm. The irradiation (exposure) of the ultraviolet is preferably 200~5000mJ / cm ^2, further preferably 500~2000mJ / cm ^2. If the irradiation (exposure) amount of ultraviolet rays is less than 100 mJ / cm ² , crosslinking may be insufficient. On the other hand, when the irradiation (exposure) amount of ultraviolet rays is more than 5000 mJ / cm ² , the obtained molded article for laser processing tends to be hard and the flexibility tends to be insufficient.

  When the molded product for laser processing of the present invention is a sheet-shaped molded product (laser processing sheet), a sheet-like base material layer is preferably laminated on one surface thereof. By setting it as such a laminated body, while preventing the deformation | transformation of the molded article for laser processing, the printing pressure required in the case of printing can be made low. In addition, the entire laser processing sheet can be reduced in weight, which is suitable for a relatively large sheet. In addition, as a material which comprises a base material layer, synthetic resin materials, such as PET resin, an acrylic resin, and ABS resin; Metal materials, such as steel and aluminum, etc. can be mentioned. Among these, when it is desired to impart transparency to the laser processing sheet, a synthetic resin material having excellent transparency such as PET resin and acrylic resin is preferable.

  The thickness of the base material layer is preferably 0.02 mm to 1 mm, more preferably 0.03 mm to 0.5 mm, and particularly preferably 0.04 mm to 0.2 mm. When the thickness of the base material layer is less than 0.02 mm, sufficient strength and characteristics as a base material tend to be hardly exhibited. On the other hand, if it exceeds 1 mm, the plate tends to be too hard and workability tends to decrease.

  The thickness of the laser processing sheet is preferably 0.3 mm to 7 mm, and more preferably 0.5 mm to 3 mm. If it is less than 0.5 mm, the laser tends to penetrate easily, although it depends on the intensity of the irradiated laser. On the other hand, if it exceeds 7 mm, it is too thick, so that not only the handleability is lowered but also the crosslinkability using UV or EB tends to be lowered.

2. Flexographic printing plate:
The flexographic printing plate of the present invention is obtained by engraving a processed surface of the above-described molded product for laser processing with a laser to form a predetermined printing pattern. That is, the flexographic printing plate of the present invention can be manufactured by forming a predetermined printing pattern on the processed surface by engraving the processed surface of the molded article for laser processing with a laser. Therefore, the flexographic printing plate of the present invention can be easily manufactured with excellent engraving accuracy and has a sufficient engraving depth.

  As a laser irradiation apparatus used when engraving a processed surface of a molded product (sheet) for laser processing, a carbon dioxide laser can be mainly mentioned. The laser intensity is preferably 10 to 500 W, more preferably 10 to 300 W per light source, although it depends on the thickness of the laser processing sheet used and the desired engraving depth. If it is less than 10 W, it tends to be difficult to form a print pattern at a sufficient engraving depth. On the other hand, if it exceeds 500 W, the strength is too strong and the engraving accuracy tends to decrease. In general, in order to increase the laser processing speed, it is preferable to increase the number of light sources and simultaneously process multiple points rather than increasing the intensity per light source.

  Engraving by laser can be performed in a state where the sheet for laser processing is arranged flat, but can also be performed in a state where the sheet for laser processing is arranged on a roll made of metal or the like. After engraving with a laser, it is preferable to clean the processed surface in order to remove the generated ash (residue). The processing surface can be cleaned by cleaning with water or an organic solvent or a surfactant solution, or by blowing or sucking an air flow.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

[Presence / absence of polymer crosslinked product]: Measured under the following conditions using a differential refractometer and a light scattering detector as a detector using a GPC measuring device (trade name “GPC TDA-302” manufactured by Viscotek). Then, an elution curve before kneading and an elution curve after kneading were prepared by the LALLS method.
Column: manufactured by Tosoh Corporation, trade name “GMHHR-H”
Column temperature: 40 ° C
Mobile phase: Tetrahydrofuran Flow rate: 1.0 ml / min
Sample concentration: 50 mg / 20 ml

Comparing the elution curve before kneading with the elution curve after kneading, based on the presence or absence of peak growth in the low retention capacity region (polymer region) in the elution curve after kneading, the polymer cross-linked product is generated according to the following criteria The presence or absence was confirmed.
Yes: Peak growth can be confirmed No: Peak growth cannot be confirmed

  [Melt flow rate (MFR (g / 10 min))]: Measured under conditions of 230 ° C. and 21.2 N load according to JIS K7210.

  [100% modulus (M100 (MPa))]: Measured according to JIS K6251.

  [Tensile breaking elongation (%)]: Measured according to JIS K6251.

  [Hardness (Duro A)]: Measured using “Asker CL150 / DD2 DURMETER” (trade name) manufactured by Kobunshi Keiki Co., Ltd. in accordance with JIS K6253.

[Evaluation of laser processability (engraving)]: A laser processing machine (manufactured by Great Computer Corporation, trade name “Laser Pro”) equipped with a closed carbon dioxide laser oscillator (manufactured by Thinrad, USA, output = 25 W) Using the settings as SPEED 30 (%), POWER 95 (%), and resolution 1000 (dpi), laser processing was performed on the processed surface of the laser processing sheet. The processed surface after laser processing was observed using a surface observation device (manufactured by Keyence Corporation), and laser processing property (engraving property) was evaluated according to the following criteria.
A: There is no adhesion on the engraving surface, and the edge of the small convex part is clear.
○: There is no adhesion on the engraved surface, but the edges of the small convex portions are not partially clear.
Δ: There is no adhesion on the engraving surface, but the edge of the large convex portion is not clear.
X: Adhesive on the engraving surface, not engraving.

Example 1
Syndiotactic 1,2-polybutadiene (trade name “RB820”, manufactured by JSR, 1,2-vinyl bond content: 92%, crystallinity: 25%), 100 parts, bis (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide (trade name “Irgacure 819”, manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.5 part, and trimethylolpropane trimetallate (Shin Nakamura Chemical Co., Ltd.) 0.5 part, dipentamethylene thiuram Tetrasulfide (trade name “Sunseller TRA”, manufactured by Sanshin Chemical Industry Co., Ltd.) 0.3 part, activated zinc white (manufactured by Sakai Chemical Industry Co., Ltd.) 0.2 part, and stearic acid (produced by Kao Corporation) 0.2 part The mixture was put into a kneader adjusted to 120 ° C. and kneaded for 3 minutes, then heated to 150 ° C. and dynamically cross-linked while kneading for 15 minutes to obtain a cross-linked product. The obtained crosslinked product had an MFR of 8 g / 10 min, an M100 of 5.3 MPa, a tensile elongation at break of 650%, and a hardness (duro A) of 91. Moreover, the confirmation result of the polymer crosslinked body formation by GPC-LALLS method was “Yes”. A GPC chart of the crosslinked product is shown in FIG.

  The obtained cross-linked product was formed into a pellet shape with an extruder set at a temperature of 150 ° C., and the pellet was formed into a sheet shape with a thickness of 1.0 mm with an extruder set at a temperature of 150 ° C. Ultraviolet irradiation was carried out under the product name “Eye Grandage ECS301G1” (manufactured by Eye Graphics Co., Ltd.) to produce a laser processing sheet, where the ultraviolet irradiation surface was used as the laser processed surface, and M100 of the prepared sheet was 5.9 MPa. The tensile elongation at break was 560%, and the hardness (duro A) was 90. The laser processability (engraving property) evaluation result was “◯”.

(Examples 2-8, Comparative Examples 1-10)
A laser processing sheet was prepared in the same manner as in Example 1 except that the formulation shown in Tables 1 and 2 and the presence or absence of dynamic thermal crosslinking were used. Tables 1 and 2 show measurement results of various physical properties and evaluation results of characteristics. Moreover, the detail of each component shown to Table 1 and 2 is shown below. A GPC chart of the crosslinkable composition obtained in Comparative Example 3 is shown in FIG.

(1) RB820: trade name of syndiotactic 1,2-polybutadiene (manufactured by JSR)
(2) SIS5200P: trade name of styrene-isoprene-styrene block copolymer (manufactured by JSR)
(3) Aerosil R972: trade name of anhydrous silica particles (manufactured by Nippon Aerosil Co., Ltd., average primary particle size = 0.017 µm)
(4) Diana process oil PW90: trade name of paraffinic extension oil (manufactured by Idemitsu Kosan Co., Ltd., VGC value = 0.802)
(5) Irgacure 819: trade name of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba Specialty Chemicals)
(6) Perhexa 3M-40V: trade name of 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane (manufactured by NOF Corporation, temperature at which half-life is 1 minute = 145 ° C.)
(7) Sunseller TRA: trade name of dipentamethylene thiuram tetrasulfide (manufactured by Sanshin Chemical Industry Co., Ltd.)

  As shown in Tables 1 and 2, the laser processing sheets prepared in Examples 1 to 8 have better elongation and flexibility than the laser processing sheets prepared in Comparative Examples 1 to 6, It is clear that the engraving property by laser is excellent. In Comparative Examples 7 to 10, a crosslinked product having a high degree of crosslinking and low fluidity was obtained by dynamic thermal crosslinking, and thus could not be formed into a sheet.

  The molded product for laser processing produced by the method for producing a molded product for laser processing of the present invention is suitable as a sheet for laser processing used mainly for producing a flexographic printing plate for letterpress printing.

It is the GPC chart measured in order to confirm the presence or absence of polymeric crosslinked body production | generation.

Claims (11)

(A) It consists of syndiotactic 1,2-polybutadiene, styrene / isoprene copolymer, and styrene / butadiene copolymer having a 1,2-vinyl bond content of 70% or more and a crystallinity of 5 to 50%. 100 parts by mass of at least one thermoplastic polymer selected from the group, (B) 0 to 50 parts by mass of silica particles, and (C) a viscosity specific gravity constant (VGC value) of 0.790 to 0 0 to 200 parts by weight of an extending oil that is 999, (D) 0 to 10 parts by weight of a photopolymerization initiator, and (E) 0 to 20 parts by weight of a polyfunctional acrylate ,
Furthermore, the (F) an organic peroxide 0.01 to 0.1 parts by weight or crosslinking composition comprising (G) sulfur or a sulfur compound 0.01 to 1.0 parts by weight,
A method for producing a molded article for laser processing, comprising dynamically thermal crosslinking followed by radiation crosslinking.   The method for producing a molded article for laser processing according to claim 1, wherein the silica particles (B) are anhydrous particles having an average primary particle diameter of 0.005 µm or more and less than 0.1 µm.   The method for producing a molded article for laser processing according to claim 1 or 2, wherein the (C) extending oil is at least one of a paraffinic extending oil and a naphthenic extending oil.   The said (D) photoinitiator is an acylphosphine oxide type compound, The manufacturing method of the molded article for laser processing as described in any one of Claims 1-3.   The method for producing a molded article for laser processing according to any one of claims 1 to 4, wherein the (E) polyfunctional acrylate is at least one of trimethylolpropane trimethacrylate and trimethylolpropane triacrylate.   The molded article for laser processing according to any one of claims 1 to 5, wherein the organic peroxide (F) has a half-life of 1 minute at a temperature of 90 ° C or higher and lower than 180 ° C. Manufacturing method.   The method for producing a molded article for laser processing according to any one of claims 1 to 6, wherein the radiation used for the radiation crosslinking is an ultraviolet ray or an electron beam.   Laser processing molding, which is a sheet-like molded product having a processed surface capable of laser engraving on at least one surface, produced by the method for producing a molded product for laser processing according to any one of claims 1 to 7. Goods.   The molded product for laser processing according to claim 8, wherein a sheet-like base material layer is laminated on one surface.   A flexographic printing plate in which the processed surface of the molded article for laser processing according to claim 8 or 9 is engraved with a laser to form a predetermined printing pattern. A crosslinkable composition used in the method for producing a molded article for laser processing according to any one of claims 1 to 7,
(A) It consists of syndiotactic 1,2-polybutadiene, styrene / isoprene copolymer, and styrene / butadiene copolymer having a 1,2-vinyl bond content of 70% or more and a crystallinity of 5 to 50%. 100 parts by mass of at least one thermoplastic polymer selected from the group, (B) 0 to 50 parts by mass of silica particles, and (C) a viscosity specific gravity constant (VGC value) of 0.790 to 0 0 to 200 parts by weight of an extending oil that is 999, (D) 0 to 10 parts by weight of a photopolymerization initiator, and (E) 0 to 20 parts by weight of a polyfunctional acrylate , and (F) an organic peroxide 0 .01～0.1 parts by or (G) sulfur or a sulfur compound 0.01 to 1.0 parts by weight crosslinkable composition comprising a.

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