Thermoplastic resin composition for laser-cut products and its manufacturing method, molded product for laser-cut products, and laser-cut product and its manufacturing method.

Abstract

Provided is a thermoplastic resin composition for a laser-cut product, which contains a thermoplastic resin containing a bonded sulfur atom and is capable of reducing an abnormal odor during laser cutting. 【Solution means】The thermoplastic resin composition of the present disclosure contains a thermoplastic resin (T) having a bonded sulfur atom amount of 0.001 to 0.1 mmol / g and a phosphorus-based antioxidant (AO-P) containing a chemical structure represented by formula (1) in one molecule. The content of the phosphorus-based antioxidant (AO-P) is 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin (T), and it is for a laser-cut product. P-R 1 (-R 2 )(-R 3 )···(1) (R 1 , R 2 , and R 3 are each independently an organic group, and two or more of these groups may be bonded to form one or more rings.)

Description

[Technical Field]

[0001] This disclosure relates to a thermoplastic resin composition for laser-cut products, a method for producing the same, a molded article for laser cutting, and a laser-cut product and a method for producing the same. [Background technology]

[0002] Inkjet printing has expanded to include a wider variety of printable media and is now used in various fields such as advertising media and signs / displays like posters, signs, and stickers; events and amusement; architecture and interiors; and general merchandise. Besides paper, other printing media include thin molded articles such as sheets or plates made from transparent thermoplastic resins like acrylic and styrene resins. For example, Patent Documents 1 and 2 disclose a laminate having a base layer containing a methacrylic resin and a surface layer containing a styrene copolymer such as methyl methacrylate-styrene copolymer (MS resin), which has good ink adhesion and laser cutting properties (Claim 1 of Patent Document 1, Claim 1 of Patent Document 2).

[0003] Thin molded bodies, such as sheets or plates, can be molded into desired shapes by inkjet printing images of anime characters and idols on at least one surface, followed by laser cutting. Laser-cut products obtained in this way can be preferably used for novelty goods such as keychains, charms attached to mobile phone straps, figurines or figurine stands on which they are placed, and panels; as well as accessories such as pendants and badges. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-94843 [Patent Document 2] Japanese Patent Publication No. 2021-160119 [Patent Document 3] Japanese Patent Publication No. 2013-144786 [Patent Document 4] Japanese Patent Publication No. 2013-245344 [Overview of the project] [Problems that the invention aims to solve]

[0005] Generally, in laser cutting, depending on the material of the workpiece, the laser beam irradiation can cause the workpiece to reach high temperatures (e.g., 300°C or higher), which can lead to melting, decomposition, and evaporation of the workpiece, resulting in an unpleasant odor from the evaporated gas. The above-mentioned transparent thermoplastic resin can be produced by radical polymerization of one or more vinyl monomers, such as acrylic monomers and styrene monomers. In this method, thiol-based chain transfer agents with large chain transfer constants, such as n-octyl mercaptan and n-dodecyl mercaptan, are preferably used to adjust the molecular weight. In radical polymerization reaction mechanisms using thiol-based chain transfer agents, sulfur atoms or groups containing sulfur atoms in the chain transfer agent may bond to the ends of the polymer. Polymers containing bonded sulfur atoms may emit an unpleasant odor (specifically a sulfurous odor) during laser cutting.

[0006] Patent documents 3 and 4 disclose non-thiol chain transfer agents having a specific condensed polycyclic aromatic skeleton or chain transfer agent compositions containing the same, for the purpose of solving odor problems (Claim 1 of Patent Document 3, Claim 1 of Patent Document 4). However, the non-thiol chain transfer agents (compositions) disclosed in these documents have low reactivity and poor yield of the target product. These documents do not disclose means to solve off-odors during laser cutting of molded articles containing thermoplastic resins containing bonded sulfur atoms.

[0007] This disclosure has been made in view of the above issues, and aims to provide a thermoplastic resin composition for laser-cut products that includes a thermoplastic resin containing bonded sulfur atoms and is capable of reducing off-odors during laser cutting. [Means for solving the problem]

[0008] The present disclosure provides a thermoplastic resin composition for laser cutting products, a method for producing the same, a molded body for laser cutting, a laser cutting product, and a method for producing the same, as described in [1] to

[12] below. [1] A thermoplastic resin (T) having a combined sulfur atomic weight of 0.001 to 0.1 mmol / g, and a phosphorus-based antioxidant (AO-P) containing a chemical structure represented by the following formula (1) within one molecule, and the content of the phosphorus-based antioxidant (AO-P) is 0.01 to 3.0 parts by mass with respect to 100 parts by mass of the thermoplastic resin (T), a thermoplastic resin composition for laser cutting products. P-R 1 (-R 2 )(-R 3 )···(1) (In the above formula, R 1 , R 2 , and R 3 are each independently an organic group, and two or more of these groups may be bonded to form one or more rings.)

[0009] [2] The thermoplastic resin composition according to [1], wherein the organic group is a group represented by the general formula R or OR (where R is an alkyl group having 1 to 22 carbon atoms or an aryl group which may have a substituent).

[0010] [3] The thermoplastic resin composition according to [1] or [2], wherein the thermoplastic resin (T) contains one or more thermoplastic resins selected from the group consisting of methacrylic resins (M) and styrene resins (S). [4] The thermoplastic resin composition according to any one of [1] to [3], wherein the phosphorus-based antioxidant (AO-P) contains a phosphorus-based antioxidant having a structure in which two or more of R 1 , R 2 , and R 3 are bonded to form one or more rings, a spiro structure, or a biphenyl structure. [5] The thermoplastic resin composition of [4], wherein the phosphorus-based antioxidant (AO-P) contains a phosphorus-based antioxidant having a spiro structure and an aryl group in one molecule.

[0011] [6] A molded body for laser cutting, having a single-layer structure or a laminated structure, which is made of the thermoplastic resin composition according to any one of [1] to [5]. [7] The molded body for laser cutting of [6], which is an extruded plate. [8] The molded body for laser cutting of [6] or [7], which has a printed layer on at least a part of the surface.

[0012] [9] A laser-cut product, which is made of the molded body for laser cutting according to any one of [6] to [8].

[10] The laser-cut product of [9], which is a novelty item.

[0013]

[11] A step (S1) of producing a thermoplastic resin (T) having a combined sulfur atomic weight of 0.001 to 0.1 mmol / g by radical polymerization of a polymerization raw material containing a vinyl monomer in the presence of a thiol-based chain transfer agent, and a step (S2) of adding a phosphorus-based antioxidant (AO-P) to the thermoplastic resin (T). A method for producing the thermoplastic resin composition according to any one of [1] to [5].

[12] A method for producing a laser-cut product, which comprises laser-cutting the molded body for laser cutting according to any one of [6] to [8].

Advantages of the Invention

[0014] According to the present disclosure, it is possible to provide a thermoplastic resin composition for a laser-cut product, which contains a thermoplastic resin containing a combined sulfur atom and can reduce an abnormal odor during laser cutting.

Brief Description of the Drawings

[0015] [Figure 1] It is a schematic cross-sectional view showing an example of a molded body for laser cutting having a laminated structure.

Modes for Carrying Out the Invention

[0016] Generally, the terms "film," "sheet," or "plate" are used for thin molded articles, depending on their thickness, but there are no clear definitions of these terms, and no clear distinction between them. In this specification, "plate" may include "sheet."

[0017] In this specification, (meth)acrylic is a general term for acrylic and methacrylic, and the same applies to (meth)acrylic acid, (meth)acrylamide, and (meth)acrylonitrile, etc. In this specification, unless otherwise specified, "alkyl groups having 3 or more carbon atoms" may be linear or branched. Compounds that have isomers include all isomers.

[0018] [Thermoplastic resin composition for laser-cut products] The thermoplastic resin composition for laser-cut products of this disclosure comprises one or more thermoplastic resins (T) having a bonded sulfur atom weight of 0.001 to 0.1 mmol / g, and one or more antioxidants (AO) including a phosphorus-based antioxidant (AO-P) having a specific chemical structure.

[0019] (Thermoplastic resin (T)) A thermoplastic resin (T) with a bonded sulfur atom weight of 0.001 to 0.1 mmol / g can be produced by radical polymerization of a polymerization raw material containing one or more vinyl monomers, such as acrylic monomers and styrene monomers, in the presence of one or more thiol-based chain transfer agents. Molecular weight can be suitably adjusted by using a thiol-based chain transfer agent with a large chain transfer constant. In the radical polymerization reaction mechanism using a thiol-based chain transfer agent, sulfur atoms contained in the chain transfer agent or groups containing them can be bonded to the ends of the polymer.

[0020] Thiol-based chain transfer agents are organic compounds having a thiol group (-SH), and include alkyl mercaptans such as ethyl mercaptan, n-butyl mercaptan, n-hexyl mercaptan, n-octyl mercaptan, and n-dodecyl mercaptan; thiolphenols such as phenyl mercaptan and benzyl mercaptan; hydroxyl-containing mercaptans such as thioglycolic acid and 3-mercaptopropionic acid; and mercaptans having multiple thiol groups in a single molecule, such as pentaerythritol tetrakis(3-mercapto)propionate.

[0021] The amount of bound sulfur atoms in the thermoplastic resin (T) can be adjusted by the type and amount of thiol-based chain transfer agent used during radical polymerization, polymerization temperature, polymerization time, and other polymerization conditions. The lower limit of the amount of bound sulfur atoms in the thermoplastic resin (T) can be 0.002 mmol / g or 0.003 mmol / g. The upper limit can be 0.090 mmol / g, 0.080 mmol / g, 0.070 mmol / g, 0.060 mmol / g, 0.050 mmol / g, 0.040 mmol / g, 0.030 mmol / g, 0.020 mmol / g, or 0.010 mmol / g. The amount of bound sulfur atoms in the thermoplastic resin (T) can be measured by the method described in the [Examples] section below.

[0022] Examples of thermoplastic resins (T) include (meth)acrylic resins; styrene resins; polyolefin resins such as polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and polynorbornene; polycarbonate resins and polycarbonate-ABS resin alloys; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as nylon 6, nylon 66, and polyamide elastomers; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacetal, polyvinylidene fluoride; polyurethane, phenoxy resin, modified polyphenylene ether, polyphenylene sulfide; styrene thermoplastic elastomers such as SEPS, SEBS, and SIS; olefin rubbers such as IR, EPR, and EPDM; and biodegradable resins.

[0023] The thermoplastic resin (T) may preferably include one or more thermoplastic resins selected from the group consisting of methacrylic resins (M) and styrene resins (S).

[0024] <Methacrylic resin (M)> The methacrylic resin (M) is a homopolymer or copolymer comprising one or more methacrylic acid ester units and, optionally, one or more other monomer units. In this specification, known methacrylate esters may be used, and specific examples include alkyl methacrylates such as methyl methacrylate (MMA), ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, and dodecyl methacrylate; 1-methylcyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, cyclooctyl methacrylate, and tricyclo[5.2.1.0 2,6Examples include cycloalkyl methacrylates such as deca-8-yl; aryl methacrylates such as phenyl methacrylate; and aralkyl methacrylates such as benzyl methacrylate. From the viewpoint of availability, MMA, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate are preferred, with MMA being the most preferred.

[0025] The content of methacrylic acid ester units in the methacrylic resin (M) (total amount if there are multiple types) is preferably 90 to 100% by mass. The lower limit is more preferably 95% by mass, and particularly preferably 98% by mass. The methacrylic resin (M) preferably contains methyl methacrylate (MMA) units, and the MMA unit content in the methacrylic resin (M) is preferably 80 to 100% by mass. The lower limit is more preferably 90% by mass, particularly preferably 95% by mass, and most preferably 98% by mass.

[0026] Other monomers besides methacrylic acid esters include acrylic acid esters; unsaturated carboxylic acids such as (meth)acrylic acid, maleic anhydride, maleic acid, and itaconic acid; olefins such as ethylene, propylene, 1-butene, isobutylene, and 1-octene; conjugated dienes such as butadiene, isoprene, and myrcene; aromatic vinyl monomers such as styrene (St), α-methylstyrene (αMSt), and o-, m-, or p-methylstyrene; (meth)acrylamide, (meth)acrylonitrile; vinyl acetate, vinylpyridine, vinyl ketone, vinyl chloride, vinylidene chloride, and vinylidene fluoride.

[0027] In this specification, known acrylic acid esters can be used, and specific examples include methyl acrylate (MA), ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, pentadecyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate, allyl acrylate, cyclohexyl acrylate, norborneyl acrylate, and isovonyl acrylate.

[0028] The stereoregularity of the methacrylic resin (M) is not particularly limited. Methacrylic resins having stereoregularity such as isotactic, heterotactic, and syndiotactic may be used. As the methacrylic resin (M), a modified methacrylic resin may be used, which is obtained by introducing a ring structure into the main chain, instead of a general methacrylic resin that does not have ring structural units in the main chain (also called an unmodified methacrylic resin).

[0029] Methacrylic resins that do not have ring structural units in the main chain can be produced by (co)polymerizing a monomer (mixture) containing a methacrylic acid ester (preferably methyl methacrylate (MMA)) and, if necessary, one or more other monomers, using a known method. Methods for producing methacrylic resins having ring structural units in the main chain include copolymerizing a plurality of monomers, including methacrylic acid ester (preferably MMA), a monomer having a ring structure, and other monomers as needed, by known methods; and a method in which a methacrylic resin containing methacrylic acid ester units (preferably MMA units) and lacking ring structural units is (co)polymerized by known methods, and then a ring structure is introduced into the main chain to form ring structural units. Polymerization methods for methacrylic resins include radical polymerization methods such as suspension polymerization, (continuous) bulk polymerization, solution polymerization, and emulsion polymerization; anionic polymerization, etc., with radical polymerization being preferred.

[0030] <Styrene resin (S)> The styrene-based resin (S) is a homopolymer or copolymer that contains one or more styrene-based monomer units and, if necessary, one or more other monomer units. Examples of styrene monomer units include styrene (St), α-methylstyrene (αMSt), o-, m-, or p-methylstyrene, and combinations thereof, with styrene (St) being preferred. Examples of styrene-based resins (S) include methyl methacrylate-styrene copolymer (MS resin), acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), butadiene-acrylonitrile-acrylic rubber-styrene copolymer (BAAS resin), methyl methacrylate-butadiene-styrene copolymer (MBS resin), acrylonitrile-acrylic rubber-styrene copolymer (AAS resin), and silicon-acrylonitrile-styrene copolymer (SAS resin), as well as high-impact polystyrene (HIPS resin) obtained by graft copolymerization of butadiene.

[0031] The styrene-based resin (S) may also be a styrene-based block copolymer. Examples of styrene-based block copolymers include XY-type diblock copolymers or XYX-type triblock copolymers consisting of a styrene polymer block (X) and a butadiene polymer block or isoprene polymer block (Y), and hydrogenated versions thereof.

[0032] As the styrene-based resin (S), one or more styrene-based copolymers selected from the group consisting of methyl methacrylate-styrene copolymer (MS resin), acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), and styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) are preferred. Acrylonitrile-styrene-based copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), or a combination thereof is more preferred.

[0033] The styrene (St) unit content in the acrylonitrile-styrene copolymer (AS resin) is preferably 75 to 95% by mass. The lower limit is more preferably 76% by mass, and particularly preferably 77% by mass. The upper limit is more preferably 90% by mass, even more preferably 88% by mass, particularly preferably 85% by mass, and most preferably 83% by mass. Examples of commercially available AS resins include "Lytac-A 100PCF" and "120PCF" from Nippon A&L Co., Ltd.; "Sunrex SAN-C," "SAN-R," and "SAN-H" from Techno UMG Co., Ltd.; "Denka AS AS-C-800" and "AS-C-820" from Denka Co., Ltd.; "Toyolac" from Toray Industries Inc.; and "Sebian N" from Daicel Mirise Co., Ltd.

[0034] The styrene (St) unit content in the styrene-maleic anhydride copolymer (SMA resin) is preferably 60 to 95% by mass. The lower limit is more preferably 70% by mass, and particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 85% by mass, and most preferably 80% by mass. Commercially available SMA resins include "XIRAN" and "XIBOND" from Polyscope, "SMA-700" from Jiaxing Huawen Chemical, and "SAM-020" from Fine-blendPolymer.

[0035] The styrene (St) unit content in the styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin) is preferably 60 to 95% by mass. The lower limit is more preferably 70% by mass, and particularly preferably 75% by mass. The upper limit is more preferably 90% by mass, particularly preferably 85% by mass, and most preferably 80% by mass. Examples of commercially available SMM resins include Denka's "Resifye R-200".

[0036] The styrene (St) unit content in the methyl methacrylate-styrene copolymer (MS resin) is preferably 35 to 85% by mass. The upper limit is more preferably 80% by mass, even more preferably 75% by mass, even more preferably 70% by mass, even more preferably 65% ​​by mass, even more preferably 60% by mass, even more preferably 55% by mass, particularly preferably 50% by mass, and most preferably 45% by mass. Commercially available MS resins include "Toyo MS MS600, MS200" from Toyo Styrene Co., Ltd.; "Denka TX Polymer TX-100S" from Denka Corporation; and "Sebian NAS" from Daicel Mirise Co., Ltd.

[0037] The content of thermoplastic resin (T) (total amount in the case of multiple types) in the thermoplastic resin composition of this disclosure is not particularly limited, but is preferably 90 to 100% by mass. The lower limit is more preferably 92% by mass, and particularly preferably 95% by mass.

[0038] <Antioxidant (AO)> The thermoplastic resin composition for laser-cut products of this disclosure comprises one or more antioxidants (AO), including a phosphorus-based antioxidant (AO-P) having a specific chemical structure.

[0039] Phosphorus-based antioxidants (AO-P) contain one or more chemical structures represented by the following formula (1) within a single molecule. PR 1 (-R 2 )(-R 3 )···(1) (In the above formula, R 1 , R 2, and R 3 Each of these groups is independently an organic group, and two or more of these groups may be bonded together to form one or more rings.

[0040] R 1 , R 2 , and R 3 Each of these can independently be a group represented by the general formula R or OR. Here, R is an alkyl group having 1 to 22 carbon atoms or an aryl group which may have substituents. The lower limit of the number of carbon atoms in the alkyl group is more preferably 2, particularly preferably 3, and most preferably 4. The upper limit is more preferably 21, even more preferably 20, particularly preferably 19, and most preferably 18. Alkyl groups with 3 or more carbon atoms may be linear or branched. The substituents that the aryl group may have include a methyl group, an i-propyl group, and a t-butyl group, with the t-butyl group being preferred. As the aryl group, a phenyl group is preferred, and a hindered phenyl group having sterically hindered substituents such as an i-propyl group and a t-butyl group is more preferred. That is, R 1 , R 2 , and R 3 Each of these is more preferably an alkyl group having 1 to 22 carbon atoms, an alkoxy group having 1 to 22 carbon atoms, a phenyl group which may have a substituent (preferably a hindered phenyl group), or a phenoxy group which may have a substituent (preferably a hindered phenoxy group).

[0041] Specific examples of phosphorus-based antioxidants (AO-P) include 3,9-bis(2,4-di-t-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(4-nonylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and 3,9-bis Examples include s(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphró[5.5]undecane, 2,2'-methylenebis(4,6-di-t-butylphenyl)2-ethylhexyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, trisnonylphenyl phosphite, 2-ethylhexyl-diphenyl phosphite, isodecyldiphenyl phosphite, triisodecyl phosphite, triphenyl phosphite, p,p,p',p'-tetrakis(2,4-di-t-butylphenoxy)-4,4'(or 3',4)-biphenyldiphosphine triethyl phosphite, and triethyl phosphite.

[0042] Among the above, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,4-di-t-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(4-nonylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane Preferred are 3,9-bis[2,4-bis(1-methyl-1-phenylethyl)phenoxy]-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 2,2'-methylenebis(4,6-di-t-butylphenyl)2-ethylhexyl phosphite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, p,p,p',p'-tetrakis(2,4-di-t-butylphenoxy)-4,4'(or 3',4)-biphenyldiphosphine triethyl phosphite, and triethyl phosphite.

[0043] Phosphorus-based antioxidants (AO-P) contain R in one molecule. 1 , R 2 , and R 3 It is preferable to include one or more phosphorus-based antioxidants having a structure in which two or more of the groups are bonded to form one or more rings, a spiro structure, or a biphenyl structure. The phosphorus-based antioxidant (AO-P) more preferably contains one or more phosphorus-based antioxidants having a spiro structure and an aryl group within a single molecule. Phosphorus-based antioxidants having a spiro structure and an aryl group within a single molecule include 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,4-di-t-butylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and 3,9-bis(4-nonylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane. In particular, from the viewpoint of the thermal stability of the antioxidant itself, 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane is preferred.

[0044] As the phosphorus-based antioxidant (AO-P), a multi-component phosphorus-based antioxidant containing multiple types of phosphorus-based antioxidants may be used. One or more commercially available phosphorus-based antioxidants (AO-P) can be used.

[0045] In the thermoplastic resin composition for laser-cut products of this disclosure, the content of phosphorus-based antioxidant (AO-P) (total amount if there are multiple types) is 0.01 to 3.0 parts by mass per 100 parts by mass of thermoplastic resin (T) (total amount if there are multiple types). The lower limit is more preferably 0.02 parts by mass, even more preferably 0.05 parts by mass, even more preferably 0.07 parts by mass, even more preferably 0.10 parts by mass, even more preferably 0.15 parts by mass, 0.17 parts by mass, even more preferably 0.20 parts by mass, even more preferably 0.25 parts by mass, even more preferably 0.30 parts by mass, even more preferably 0.40 parts by mass, even more preferably 0.50 parts by mass, particularly preferably 0.70 parts by mass, and most preferably 1.0 part by mass. The upper limit is more preferably 2.7 parts by mass, even more preferably 2.5 parts by mass, particularly preferably 2.2 parts by mass, and most preferably 2.0 parts by mass.

[0046] Molded articles containing thermoplastic resin (T) with bound sulfur atoms may emit an unpleasant odor (specifically a sulfurous odor) during laser cutting. According to the inventors' research, it has been found that adding an appropriate amount of a specific phosphorus-based antioxidant (AO-P) to a thermoplastic resin (T) containing bound sulfur atoms can effectively suppress off-odors (specifically sulfurous odors) during laser cutting. The mechanism is not entirely clear, but it can be inferred as follows: During laser cutting, the cutting area typically exceeds 300°C. Therefore, thermoplastic resins (T) containing bound sulfur atoms are thought to undergo thermal decomposition, generating thiyl radical compounds with a strong sulfurous odor derived from these bound sulfur atoms. Phosphorus-based antioxidants (AO-P) are thought to effectively capture the thiyl radicals derived from the bound sulfur atoms generated by the decomposition, producing compounds with a weaker sulfurous odor and a phosphorus-sulfur bond. The estimated reaction equation for this process is shown below. R'-SH+PR3→ R'-H+S=PR3

[0047] If the content of phosphorus-based antioxidants (AO-P) is below the above upper limit, the bleed-out of phosphorus-based antioxidants (AO-P) from laser-cut products can be suppressed. Furthermore, if the phosphorus-based antioxidant (AO-P) contains aromatic rings, there is a risk of off-odors originating from these rings during laser cutting. If the content of the phosphorus-based antioxidant (AO-P) is below the above upper limit, off-odors originating from the aromatic rings contained in the phosphorus-based antioxidant (AO-P) can be effectively suppressed.

[0048] The thermoplastic resin compositions of this disclosure may optionally contain one or more antioxidants other than the phosphorus-based antioxidant (AO-P). Examples of other antioxidants include phenolic antioxidants (AO-F), lactone-based antioxidants, and hydroxyl-based antioxidants. Among these, phenolic antioxidants (AO-F) are preferred.

[0049] Examples of phenolic antioxidants (AO-F) include pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-(1,6-hexanediyl)bis[3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanamide], 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate. Examples include stearyl benzoate, 4,4'-butylidenebis(6-t-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, bis[3-[3-(t-butyl)-4-hydroxy-5-methylphenyl]propanoic acid]2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl), and 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl4'-hydroxybenzyl).

[0050] <Other additives> The thermoplastic resin compositions of this disclosure may optionally contain one or more additives other than antioxidants. Examples of additives include colorants such as dyes, pigments, organic dyes, and phosphors; thermal degradation inhibitors, ultraviolet absorbers, light stabilizers; lubricants, mold release agents; polymer processing aids; antistatic agents; flame retardants; light diffusers, matting agents, and the like. The content of additives in the thermoplastic resin composition of this disclosure can be designed as appropriate. For every 100 parts by mass of thermoplastic resin (T) (or 100 parts by mass in total if there are multiple types), it is preferable that the content of the ultraviolet absorber be 0.01 to 3 parts by mass, the content of the light stabilizer be 0.01 to 3 parts by mass, and the content of the lubricant be 0.01 to 3 parts by mass. The timing of adding other additives, as needed, is not particularly limited and can be arbitrary, such as before, during, or after the production of the thermoplastic resin (T), or during the production of the thermoplastic resin composition.

[0051] [Method for producing thermoplastic resin compositions] The method for producing the thermoplastic resin composition of this disclosure is not particularly limited. A step (S1) to produce a thermoplastic resin (T) having a bonded sulfur atom weight of 0.001 to 0.1 mmol / g by radical polymerization of a polymerization raw material containing one or more vinyl monomers in the presence of one or more thiol chain transfer agents, The process may include a step (S2) of adding one or more phosphorus-based antioxidants (AO-P) to a thermoplastic resin (T). Since phosphorus-based antioxidants (AO-P) inhibit the radical polymerization reaction, it is preferable to add one or more phosphorus-based antioxidants (AO-P) to the thermoplastic resin (T) obtained after the completion of the radical polymerization step (step (S1)).

[0052] [Molded products and molding methods for laser cutting] The form of the molded body for laser cutting according to this disclosure is not particularly limited and includes planar objects with single-layer or laminated structures such as films, sheets, and plates; fibers, pipes, tubes, rods; and any three-dimensional structures. Surface treatments such as printing, painting, plating, vapor deposition, and sputtering, as well as shape processing such as bending and folding, may be performed on the molded body obtained by known molding methods as needed. The molding method is not particularly limited and includes extrusion molding, injection molding (insert method, two-color method, press method, core-back method, and sandwich method, etc.), melt molding methods such as inflation molding, blow molding, and calendering; compression molding (also called press molding); vacuum forming, pressure forming, and vacuum pressure forming; and solution casting.

[0053] The molded articles for laser cutting according to this disclosure are preferably resin plates having a single-layer or laminated structure. Examples of methods for molding the resin plates include solution casting, extrusion molding, compression molding (press molding), inflation molding, blow molding, calendering, and molten casting, with extrusion molding and compression molding (press molding) being preferred. Among these, the extrusion molding method is preferred, and the T-die method is more preferred. That is, the molded article for laser cutting according to this disclosure is preferably an extruded sheet having a single-layer structure or a laminated structure.

[0054] The following describes the molding method for single-layer extruded sheets. The thermoplastic resin composition of this disclosure is melt-kneaded using an extruder and extruded in a molten state from a T-die having a wide discharge port. Examples of extruders include single-screw extruders, twin-screw extruders, multi-screw extruders, and combinations thereof. The melting temperature is higher than the glass transition temperature (Tg) of the thermoplastic resin composition, preferably 150 to 300°C, more preferably 200 to 300°C. From the viewpoint of suppressing discoloration, it is preferable to perform melt-kneading under reduced pressure using a vent or under a nitrogen gas stream.

[0055] To remove foreign matter, it is preferable to filter the molten resin using a filter before extrusion. By molding using the filtered molten resin, a resin sheet with fewer defects caused by foreign matter and gel can be obtained. To improve the thickness accuracy of the resin sheet, a gear pump may be installed in the extrusion molding line during the molding process. The molten resin, extruded in a plate-like form from the T-die, is cooled using multiple cooling rolls. Examples of cooling rolls include rigid metal rolls and elastic metal rolls. The single-layer resin sheet obtained after cooling is taken up by a take-up roll. The above processes of extrusion, cooling, and take-up are carried out continuously.

[0056] Laminated extruded sheets can preferably be formed by co-extrusion. In co-extrusion, the constituent resin compositions of each layer are melt-kneaded using an extruder and co-extruded in a sheet form from a T-die having a wide discharge port in the desired laminated structure. Lamination methods include a feed block method in which lamination is performed before the material enters the T-die, and a multi-manifold method in which lamination is performed inside the T-die. From the viewpoint of improving inter-layer interface smoothness, the multi-manifold method is preferred. The molten thermoplastic resin laminate co-extruded from the T-die is pressurized and cooled using a plurality of cooling rolls. The laminated resin sheet obtained after cooling is taken up by a pair of take-up rolls. The above steps of extrusion, cooling, and take-up are carried out continuously. In this specification, materials in a heated and molten state are generally referred to as "thermoplastic resin laminates," while solidified materials are referred to as "thermoplastic resin laminated resin plates," but there is no clear boundary between the two.

[0057] The first embodiment of the present invention provides a single-layer molded article for laser cutting (preferably a resin plate) comprising the above-described thermoplastic resin composition comprising one or more thermoplastic resins (T) (preferably methacrylic resins (M) and / or styrene resins (S)) having a bonded sulfur atom content of 0.001 to 0.1 mmol / g, and one or more appropriate amounts of specific phosphorus-based antioxidants (AO-P).

[0058] A laser cutting molded article (preferably a resin plate) of the second embodiment of the present invention is a laser cutting molded article having a laminated structure in which multiple layers are laminated, each layer being made of the above-mentioned thermoplastic resin composition comprising one or more thermoplastic resins (T) (preferably methacrylic resins (M) and / or styrene resins (S)) having a bonded sulfur atom content of 0.001 to 0.1 mmol / g and one or more appropriate amounts of specific phosphorus-based antioxidants (AO-P).

[0059] One example of a laminated structure is a laminated structure that includes a base layer and a surface layer laminated on at least one side of the base layer. Figure 1 shows an example of a laminated structure. Each figure in Figure 1 is a schematic cross-sectional view. The first embodiment of the laser cutting molded body 1 shown in the upper figure of Figure 1 is a two-layer laminate having a surface layer 21 on one side of a base layer 11, and the second embodiment of the laser cutting molded body 2 shown in the lower figure of Figure 1 is a three-layer laminate having surface layers 22 and 23 on both sides of the base layer 11. In the three-layer laminate, the thickness and composition of the two surface layers may be the same or different. The ratio of the total thickness of the surface layers to the thickness of the base layer is preferably 1:1 to 1:200. The laser-cut molded bodies 1 and 2 may include any other layers besides the base layer and the surface layer, as needed. However, at least one surface of the surface layer must be an exposed surface, without any other layers on it. This exposed surface may be a printed surface on which printing is applied.

[0060] The surface layer may consist of a thermoplastic resin composition containing a styrene-based resin (S) and a phosphorus-based antioxidant (AO-P). The base layer may consist of a thermoplastic resin composition containing a methacrylic resin (M) and a phosphorus-based antioxidant (AO-P), or a thermoplastic resin composition containing a methacrylic resin (M), a styrene-based resin (S), and a phosphorus-based antioxidant (AO-P).

[0061] The laser-cut molded articles of this disclosure can be inkjet printed on at least a portion of their surface. Examples of inkjet printing methods include electrostatic attraction, methods that apply mechanical vibration or displacement to the ink using piezoelectric elements such as piezo elements, methods that heat the ink to cause foaming and utilize the resulting pressure, and methods that use ultraviolet (UV) curable inks. UV curable inks are preferably used as the inkjet printing inks.

[0062] Styrene-based resins (S) having an aromatic ring structure within the molecule exhibit good penetration and adhesion of inkjet printing inks, such as UV-curable inks. A single-layer molded body for laser cutting containing styrene resin (S), a single-layer molded body for laser cutting containing methacrylic resin (M) and styrene resin (S), or a laminated molded body for laser cutting containing a base layer containing methacrylic resin (M) and a surface layer containing styrene resin (S) has a surface containing styrene resin (S). The surface containing styrene resin (S) can have good penetration and good adhesion of inkjet printing inks such as UV-curable inks. Furthermore, when the laser-cut molded body of this disclosure contains styrene monomer units, it tends to effectively reduce the amount of warping change after being left to stand in a high-humidity environment.

[0063] Styrene resins (S) having an aromatic ring structure within the molecule may produce an off-odor originating from the aromatic ring during laser cutting. In a single-layer molded body for laser cutting containing methacrylic resin (M) and styrene resin (S), or a laminated molded body for laser cutting containing a base layer containing methacrylic resin (M) and a surface layer containing styrene resin (S), the proportion of styrene monomer units in the entire molded body for laser cutting is reduced, thereby suppressing the off-odor originating from the aromatic ring during laser cutting.

[0064] Depending on the type of styrene resin (S), its compatibility with methacrylic resin (M) may be poor, and thermoplastic resin compositions containing methacrylic resin (M) and styrene resin (S) may exhibit reduced transparency. By using a styrene resin (S) with good compatibility with methacrylic resin (M), good transparency can be obtained even in thermoplastic resin compositions containing methacrylic resin (M) and styrene resin (S). Examples of styrene-based resins (S) with good compatibility with methacrylic resins (M) include acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin), and methyl methacrylate-styrene copolymer (MS resin). Among these, acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), styrene-maleic anhydride-methyl methacrylate copolymer (SMM resin), or combinations thereof are preferred, and acrylonitrile-styrene copolymer (AS resin), styrene-maleic anhydride copolymer (SMA resin), or combinations thereof are more preferred.

[0065] The total thickness of the molded body for laser cutting according to this disclosure, when it is a resin plate, is not particularly limited, but is preferably 1 to 20 mm from the viewpoint of laser cuttableness. The upper limit is more preferably 18 mm, even more preferably 15 mm, even more preferably 12 mm, even more preferably 10 mm, particularly preferably 8 mm, and most preferably 5 mm. In a molded body for laser cutting having a laminated structure including a base layer and a surface layer laminated on at least one side of the base layer, when the total thickness is 3 mm, the thickness of the base layer is preferably 2.4 to 2.9 mm, the thickness of one surface layer is preferably 30 to 300 μm, and the total thickness of the surface layers is preferably 30 to 600 μm.

[0066] The laser-cut molded articles of this disclosure may have a printed layer on at least a portion of their surface. The printed layer may have patterns such as pictures, characters, figures, colors, and combinations thereof. The printed layer can preferably be formed by inkjet printing using ultraviolet (UV) curable ink.

[0067] [Laser-cut parts] The laser-cut product of the present disclosure preferably consists of the above-mentioned laser-cut molded body for laser cutting having a printed layer on at least a portion of its surface, and is obtained by laser cutting the above-mentioned laser-cut molded body for laser cutting of the present disclosure. The laser-cut molded body of this disclosure suppresses off-odors during laser cutting and has good laser-cuttable properties, enabling fine cutting. For example, laser-cut products having curved cut sections with a radius of 0.5 to 2 mm can be manufactured with high shape accuracy. Because the laser-cut molded body of this disclosure has good laser-cuttable properties, it can be cut at high speed and with good productivity using a high-power laser processing machine. For example, the laser-cut molded body of this disclosure can be cut at a speed of 350 cm / min or more using a laser processing machine with an output of 100 W or more to manufacture laser-cut products.

[0068] As described above, this disclosure provides a thermoplastic resin composition for laser-cut products that includes a thermoplastic resin containing bonded sulfur atoms and is capable of reducing off-odors during laser cutting.

[0069] [Application] The thermoplastic resin composition for laser-cut products, the molded articles for laser-cut products, and the laser-cut products of this disclosure can be used for any application, including advertising media or signs and displays such as posters, signs, and stickers; events and amusement; architecture and interiors; and general merchandise. The thermoplastic resin compositions, laser-cut molded articles, and laser-cut products of this disclosure can be preferably used for miscellaneous goods such as ornaments, and can be preferably used for novelty goods such as keychains, charms that can be attached to mobile phone straps, figurines or figurine stands in which they are placed on a base, and panels; and accessories such as pendants and badges. [Examples]

[0070] Examples and comparative examples of the present invention will be described below. [Evaluation items and evaluation methods] (polymerization rate) The polymerization conversion rate was determined by gas chromatography analysis. A Shimadzu GC-14A gas chromatograph was connected to a GL Sciences Inc. INERTAP1 column (film thickness 0.4 μm, inner diameter 0.25 mmφ, length 60 m). The analysis was performed under the following conditions, and the polymerization conversion rate was calculated from the obtained data. Injection temperature: 250℃, Detector temperature: 250℃, Temperature profile: Hold at 60°C for 5 minutes → Increase temperature to 250°C at a rate of 10°C / min → Hold at 250°C for 10 minutes.

[0071] (Weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw / Mn)) The Mw, Mn, and Mw / Mn of the methacrylic resin (M) were determined by gel permeation chromatography (GPC) analysis. A Tosoh HLC-8320 GPC instrument was used. A series-connected configuration of Tosoh TSKgelSuperMultiporeHZ-M and TSKgelSuperHZ4000 columns was used as the separation column. A differential refractive index detector (RI detector, Tosoh RI-8020) was used as the detector. A sample solution with a concentration of 8 mg / 10 mL was prepared by dissolving the target resin in tetrahydrofuran. The column oven temperature was set to 40°C. Tetrahydrofuran was used as the eluent, and the eluent flow rate was set to 0.35 ml / min. 20 μl of the sample solution was injected into the instrument, and the chromatogram was measured. GPC measurements were performed on 10 standard polymethyl methacrylate (PMMA) samples with molecular weights in the range of 400 to 5,000,000, and a calibration curve showing the relationship between retention time and molecular weight was created. Based on this calibration curve, the Mw, Mn, and Mw / Mn of the target resin in terms of standard polymethyl methacrylate (PMMA) were determined.

[0072] (Styrene unit content in styrene resin (S)) Using a nuclear magnetic resonance spectrometer (Bruker's "ULTRA SHIELD 400 PLUS"), the styrene resin (S) 1 The 1H-NMR spectrum was measured. The unit concentration of styrene was determined from the integral value of the peaks originating from hydrogen atoms bonded to carbon atoms at positions 2-6 of the aromatic ring in styrene.

[0073] (Bound sulfur atomic weight) 0.1 g of the target resin (methacrylic resin (M) or styrene resin (S)) was mixed with 10 ml of nitric acid. The resulting solution was heat-treated using a microwave irradiation device (Milestone General "ETHOS-1600") at an output of 500-1000 W for 55 minutes. 20 ml of deionized water was added to this solution to prepare the sample solution. The amount of sulfur atoms in the sample solution was quantified using a high-frequency inductively coupled plasma (ICP) emission spectrometer (Thermo Ficher Scientific "iCAP® 7400 ICP-OES Duo Full MFC"). The mass percentage concentration of sulfur atoms relative to the mass of the resin (W) was determined. L Calculate the (mass %) and use the following formula to determine the amount of bonded sulfur atoms (S L The (mmol / g) value was calculated. The constant "32" in the formula represents the atomic weight of the sulfur atom (32 g / mol). S L =[(W L (÷100) / 32]×1000

[0074] (Odor) Four panelists evaluated the odor during laser cutting on a 5-point scale (1 to 5 points), and the average score was calculated. The scoring criteria were as follows. The methacrylic resin (M3) in the reference example (ER1) was used as the standard sample for the evaluation "1 point: No odor detected." <Scoring Criteria> 5 points: I strongly detect an unpleasant odor (sulfurous smell). 4 points: I detected an unpleasant odor (sulfurous smell). 3 points: I can detect a slight off-odor (sulfurous smell). Points 2: I can smell an odor, but I don't perceive it as an unpleasant smell (sulfurous odor). 1 point: No odor detected.

[0075] The following criteria were used for the determination. <Judgment criteria> ◎(Excellent): The average score is between 1.0 and 3.0 points. ○ (Good): The average score is 3.0 or higher but less than 3.5. × (Not acceptable): The average score of the graded items is 3.5 points or higher.

[0076] [material] The materials manufactured or prepared are as follows: (Methacrylic resin (M)) <m1> 94 parts by mass of methyl methacrylate (MMA) and 6 parts by mass of methyl acrylate (MA) were mixed with 0.1 parts by mass of a polymerization initiator (2,2'-azobis(2-methylpropionitrile), hydrogen abstraction ability: 1%, half-life temperature at 1 hour: 83°C) and 0.18 parts by mass of a thiol-based chain transfer agent (n-octyl mercaptan), and the mixture was stirred to obtain the raw material solution. A mixture was obtained by stirring and mixing 100 parts by mass of deionized water, 0.03 parts by mass of sodium sulfate, and 0.45 parts by mass of a suspension dispersant. In a pressure polymerization tank, 420 parts by mass of the mixed solution and 210 parts by mass of the raw material solution were charged as polymerization raw materials. Under a nitrogen atmosphere, the polymerization reaction was carried out at 70°C for 3 hours while stirring the reaction solution, and then at 90°C for 1 hour to obtain a dispersion of bead-shaped methacrylic resin (M1). The obtained resin dispersion was washed with an appropriate amount of deionized water, and the bead-shaped resin was separated using a bucket-type centrifuge. The dispersion was then dried at 80°C for 12 hours using a hot air dryer to obtain bead-shaped methacrylic resin (M1). The obtained methacrylic resin (M1) had a content of 94% by mass of MMA units and 6% by mass of MA units, a weight-average molecular weight (Mw) of 130,000, and a bound sulfur atom content of 0.010 mmol / g.

[0077] <m2> A bead-shaped methacrylic resin (M2) was obtained in the same manner as the methacrylic resin (M1), except that the amount of thiol-based chain transfer agent (n-octyl mercaptan) added to 94 parts by mass of methyl methacrylate (MMA) and 6 parts by mass of methyl acrylate (MA) was changed to 0.10 parts by mass. The obtained methacrylic resin (M2) had an MMA unit content of 94% by mass, an MA unit content of 6% by mass, a weight-average molecular weight (Mw) of 249,000, and a bound sulfur atom content of 0.007 mmol / g.

[0078] <m3> A 5L glass reaction vessel equipped with a stirring blade and a three-way stopcock was purged with nitrogen. Into this reaction vessel, at 23°C, 1600g of toluene, 2.49g (10.8 mmol) of 1,1,4,7,10,10-hexamethyltriethylenetetramine, 53.5g (30.9 mmol) of a toluene solution of isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum at a concentration of 0.45M, and 7.07g (11.8 mmol) of a s-butyllithium solution at a concentration of 1.3M (solvent: cyclohexane / n-hexane mixed solvent (mass ratio 95 / 5)) were charged. At 15°C, 550 g of purified methyl methacrylate (MMA) was added dropwise over 30 minutes while stirring the reaction mixture. After the addition was complete, stirring was continued at 25°C for 90 minutes to complete the reaction. At the end of the reaction, the polymerization conversion rate of methyl methacrylate (MMA) was 100%. The obtained solution was diluted with 1500 g of toluene, and the resulting diluted solution was injected into 100 kg of methanol to obtain a precipitate. The obtained precipitate was dried under reduced pressure at 80°C and 140 Pa for 24 hours to obtain a methacrylic resin (M3). The obtained methacrylic resin (M3) had an MMA unit content of 100% by mass, a weight-average molecular weight (Mw) of 70,000, a molecular weight distribution (Mw / Mn) of 1.05, and the amount of bound sulfur atoms was below the detection limit (less than 0.001 mmol / g).

[0079] (Styrene resin (S)) <as1>Acrylonitrile-styrene copolymer (AS resin), "Denka AS AS-C-820" manufactured by Denka Co., Ltd., styrene (St) unit content: 82% by mass, bound sulfur atomic weight: 0.003 mmol / g.

[0080] (Phosphorus-based antioxidant (AO-P)) <pep>3,9-Bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (PEP-36, manufactured by Adekastab) [ka]

[0081] <hp>2,2'-Methylenebis(4,6-di-t-butylphenyl)2-ethylhexyl phosphite (Adekastab "HP-10") [ka]

[0082] <oep>3,9-Bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane (PEP-8, manufactured by Adekastab) [ka]

[0083] <epq>A multi-component phosphorus-based antioxidant (HOSTANOX® P-EPQ, manufactured by Clariant Chemicals) containing the following five compounds (p,p,p',p'-tetrakis(2,4-di-t-butylphenoxy)-4,4'-biphenyldiphosphine triethyl phosphite, and p,p,p',p'-tetrakis(2,4-di-t-butylphenoxy)-3',4-biphenyldiphosphine triethyl phosphite, etc.). [ka]

[0084] <tep>Triethyl phosphite (JP-302, manufactured by Johoku Chemical Co., Ltd.) P(-OC2H5)3

[0085] (Phenol-based antioxidant (AO-F)) <aoc>Pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (AO-60, manufactured by Adekastab) [ka]

[0086] (Examples (E1) to (E11), Comparative Example (EC1)) A thermoplastic resin composition was obtained by adding 0.1 to 2.0 parts by mass of a phosphorus-based antioxidant (AO-P) or a phenol-based antioxidant (AO-F) to 100 parts by mass of a thermoplastic resin (T) (methacrylic resin (M) or styrene-based resin (S)), and melt-kneading the mixture at 230°C for 3 minutes using a Laboplast Mill (manufactured by Toyo Seiki Co., Ltd.). The obtained thermoplastic resin composition was extruded at 260°C using an extrusion molding machine into a flat plate 1 m wide and 3 mm thick, and then cut into 1 m sections. The obtained flat plate (molded body for laser cutting) was subjected to laser cutting under the following conditions to obtain 48 laser-cut parts with dimensions of 20 mm in short diameter x 30 mm in long diameter and a curved cutting section with a radius of 1 mm. <Laser cutting conditions> Equipment: SEI Corporation's "MERCURY609" Temperature: room temperature (20~30℃), Laser type: CO2 laser, Laser output: 200W, Cutting speed: 350~400cm / min, Cutting time: about 20 seconds. Table 1 shows the main manufacturing conditions and evaluation results. The unit of the blending amount in the table is "parts by mass". In the examples shown in the table, conditions not listed in the table were considered common conditions.

[0087] (Comparative examples (EC2) to (EC4), reference example (ER1)) A flat plate was obtained in the same manner as in Examples (E1) to (E11), except that a thermoplastic resin (T) (methacrylic resin (M) or styrene resin (S)) was used alone instead of the thermoplastic resin composition, and laser cutting was performed. The main manufacturing conditions and evaluation results are shown in Table 1.

[0088] [Table 1]

[0089] [Summary of results] In a reference example (ER1) using a thermoplastic resin (T) with a bonded sulfur atom content below the detection limit (less than 0.001 mmol / g), the laser cutting process was odorless even without the addition of an antioxidant (AO).

[0090] In comparative examples (EC2) to (EC4) using a thermoplastic resin (T) containing bonded sulfur atoms and without the addition of an antioxidant (AO), a noticeable off-odor (sulfurous odor) was observed during laser cutting. In comparative example (EC1), where a phenolic antioxidant (AO-F) was added to a thermoplastic resin (T) containing bonded sulfur atoms, a noticeable off-odor (sulfurous odor) was observed during laser cutting.

[0091] In Examples (E1) to (E11), in which an appropriate amount of a specific phosphorus-based antioxidant (AO-P) was added to a thermoplastic resin (T) containing bound sulfur atoms, the off-odor (sulfurous odor) during laser cutting was effectively suppressed.

[0092] The present invention is not limited to the embodiments and examples described above, and design modifications can be made as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0093] 1, 2 Molded body for laser cutting 11 Base material layer 21, 22, 23 surface layer< / aoc> < / tep> < / epq> < / oep> < / hp> < / pep>

Claims

1. A thermoplastic resin (T) having a bonded sulfur atom weight of 0.001 to 0.1 mmol / g, It contains a phosphorus-based antioxidant (AO-P) with a chemical structure represented by the following formula (1) in one molecule, The content of phosphorus-based antioxidant (AO-P) is 0.01 to 3.0 parts by mass per 100 parts by mass of thermoplastic resin (T). A thermoplastic resin composition for use in laser-cut products. P-R １ (-R ２ )(-R ３ )・・・(1) (In the above formula, R １ , R ２ , and R ３ Each of these groups is independently an organic group, and two or more of these groups may be bonded together to form one or more rings.

2. The thermoplastic resin composition according to claim 1, wherein the organic group is a group represented by the general formula R or OR (where R is an alkyl group having 1 to 22 carbon atoms or an aryl group which may have substituents).

3. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin (T) comprises one or more thermoplastic resins selected from the group consisting of methacrylic resins (M) and styrene resins (S).

4. The phosphorus-based antioxidant (AO-P) contains, within one molecule, a phosphorus-based antioxidant having a structure in which two or more of the groups of R １ , R ２ , and R ３ are bonded to form one or more rings, a spiro structure, or a biphenyl structure, the thermoplastic resin composition according to claim 1.

5. The thermoplastic resin composition according to claim 4, wherein the phosphorus-based antioxidant (AO-P) comprises a phosphorus-based antioxidant having a spiro structure and an aryl group in one molecule.

6. A single-layer or laminated molded article for laser cutting, comprising the thermoplastic resin composition described in claim 1.

7. The molded body for laser cutting according to claim 6, which is an extruded plate.

8. A molded body for laser cutting according to claim 6, having a printed layer on at least a portion of its surface.

9. A laser-cut product comprising a molded body for laser cutting according to any one of claims 6 to 8.

10. A laser-cut product according to claim 9, which is a novelty item.

11. A step (S1) to produce a thermoplastic resin (T) having a bonded sulfur atom content of 0.001 to 0.1 mmol / g by radical polymerization of a polymerization raw material containing a vinyl monomer in the presence of a thiol chain transfer agent, A method for producing a thermoplastic resin composition according to any one of claims 1 to 5, comprising the step (S2) of adding a phosphorus-based antioxidant (AO-P) to a thermoplastic resin (T).

12. A method for manufacturing a laser-cut product, comprising laser-cutting a molded body for laser cutting according to any one of claims 6 to 8.

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