Granular flame retardant composition and thermoplastic resin composition

Abstract

Provided is a granular flame retardant composition which has low mutual adhesion and a certain degree of strength, and which enables increased productivity. The granular flame retardant composition contains a bromine-containing organic compound (A) and a binder (B), the granular flame retardant composition being characterized in that: the bromine-containing organic compound (A) contains at least one bromine-containing organic compound (A1) which is selected from the group consisting of a specific bromine-containing organic compound (A1-1) that has a 2,3-dibromo-2-alkylpropyl group and a specific bromine-containing organic compound (A1-2) that has a 2,3-dibromopropyl group; and the binder (B) contains a fatty acid (B1) which has 16 to 22 carbon atoms and a melting point of 40°C to 90°C.

Description

Granular flame retardant composition and thermoplastic resin composition

[0001] The present invention relates to a granular flame retardant composition and a thermoplastic resin composition.

[0002] Bromine-containing organic compounds are widely used as flame retardants for thermoplastic resins such as polystyrene resins and ABS resins. However, when the flame retardant is in powder form, for example, it tends to scatter when measured or added to the resin, which can cause problems such as a deterioration in the working environment, adverse effects on the health of workers, and the risk of dust explosions. Furthermore, depending on the particle size and specific gravity of the flame retardant, poor fluidity can lead to problems such as clogging of the hopper when adding the flame retardant from the hopper or difficulty in pneumatic transport of the flame retardant. Therefore, a granular flame retardant composition that is less likely to scatter, has excellent fluidity, and is easy to handle is desired.

[0003] For example, Patent Document 1 discloses a granular flame retardant composition that uses an ethylene vinyl acetate copolymer as a binder for a brominated flame retardant.

[0004] Japanese Patent Application Laid-Open No. 2007-70586

[0005] However, there has been a problem in that particles of the granular flame retardant composition adhere to each other immediately after granulation, making it difficult to use the granular flame retardant composition. (Hereinafter, the property in which particles of the granular flame retardant composition adhere to each other after granulation and before cooling and solidifying, and thereafter become inseparable, is also referred to as "mutual adhesion.")

[0006] Furthermore, the granular flame retardant composition is required to be granulatable even at a high granulation speed, ie, to have high productivity, and to have a strength sufficient to prevent it from easily crumbling.

[0007] The present invention has been made to solve the above problems, and its object is to provide a granular flame retardant composition that has low mutual adhesion, a certain degree of strength, and allows for increased productivity.

[0008] The present invention includes, for example, the embodiments shown below.

[0009] [1] A granular flame retardant composition containing a bromine-containing organic compound (A) and a binder (B), wherein the bromine-containing organic compound (A) contains at least one bromine-containing organic compound (A1) selected from the group consisting of bromine-containing organic compounds (A1-1) having a 2,3-dibromo-2-alkylpropyl group and bromine-containing organic compounds (A1-2) having a 2,3-dibromopropyl group, and the bromine-containing organic compound (A1-1) is selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol-S-bis(2,3-dibromo-2-methylpropyl ether), and tetrabromobisphenol-B-bis(2,3-dibromo-2-methylpropyl ether). a bromobisphenol-F-bis(2,3-dibromo-2-methylpropyl ether); the bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromopropyl ether); and the binder (B) contains a fatty acid (B1) having 16 to 22 carbon atoms and a melting point of 40 to 90°C.

[0010] [2] The granular flame retardant composition according to the above [1], wherein the content of the fatty acid (B1) is 1 to 20% by weight of the granular flame retardant composition.

[0011] [3] The granular flame retardant composition according to [1] or [2] above, wherein the content of the bromine-containing organic compound (A1) is 20 to 99% by weight of the granular flame retardant composition.

[0012] [4] A thermoplastic resin composition containing the granular flame retardant composition according to any one of [1] to [3] above and a thermoplastic resin.

[0013] [5] A composition containing a bromine-containing organic compound (A) and a binder (B), wherein the bromine-containing organic compound (A) contains at least one bromine-containing organic compound (A1) selected from the group consisting of bromine-containing organic compounds (A1-1) having a 2,3-dibromo-2-alkylpropyl group and bromine-containing organic compounds (A1-2) having a 2,3-dibromopropyl group, and the bromine-containing organic compound (A1-1) is selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol-S-bis(2,3-dibromo-2-methylpropyl ether), and tetrabromobisphenol-B-bis(2,3-dibromo-2-methylpropyl ether). the bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromopropyl ether); and the binder (B) contains a fatty acid (B1) having 16 to 22 carbon atoms and a melting point of 40 to 90°C. Use of the composition as a granular flame retardant composition.

[0014] According to the granular flame retardant composition of the present invention, when at least one of a bromine-containing organic compound having a 2,3-dibromo-2-alkylpropyl group and a bromine-containing organic compound having a 2,3-dibromopropyl group is used as the flame retardant, a granular flame retardant composition can be provided which has low mutual adhesion, a certain degree of strength, and enables increased productivity.

[0015] Preferred embodiments of the present invention will now be described.

[0016] The granular flame retardant composition according to the present invention is a granular flame retardant composition containing a bromine-containing organic compound (A) and a binder (B), wherein the bromine-containing organic compound (A) contains at least one bromine-containing organic compound (A1) selected from the group consisting of bromine-containing organic compounds (A1-1) having a 2,3-dibromo-2-alkylpropyl group and bromine-containing organic compounds (A1-2) having a 2,3-dibromopropyl group, and the bromine-containing organic compound (A1-1) is selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol-S ... The bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromo-2-methylpropyl ether), the bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromopropyl ether), and the binder (B) contains a fatty acid (B1) having 16 to 22 carbon atoms and a melting point of 40 to 90°C. Each component will be described below.

[0017] The bromine-containing organic compound (A) of the present invention contains, for example, a bromine-containing organic compound (A1-1) having a 2,3-dibromo-2-alkylpropyl group. Specifically, the bromine-containing organic compound (A1-1) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol-S-bis(2,3-dibromo-2-methylpropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromo-2-methylpropyl ether). These compounds may be used alone or in combination of two or more.

[0018] The bromine-containing organic compound (A) of the present invention contains, for example, a bromine-containing organic compound (A1-2) having a 2,3-dibromopropyl group. Specifically, the bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether), and tetrabromobisphenol-F-bis(2,3-dibromopropyl ether). These compounds may be used alone or in combination of two or more.

[0019] The bromine-containing organic compound (A) of the present invention may contain a bromine-containing organic compound (A2) other than the bromine-containing organic compound (A1). Examples of such compounds include tris(2,3-dibromopropyl)isocyanurate and tris(2,3-dibromopropyl)cyanurate, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, tetrabromobisphenol-A, hexabromobenzene, pentabromotoluene, polybromodiphenyl ether, polybromodiphenylethane, bispolybromophenoxyethane, trispolybromophenoxytriazine, polybromophenylindane, polypentabromobenzyl acrylate, ethylenebistetrabromophthalimide, tris(tribromoneopentyl)phosphate, and brominated epoxy oligomers. These compounds may be used alone or in combination of two or more.

[0020] The content of the bromine-containing organic compound (A) of the present invention is preferably 70 to 98 parts by weight, more preferably 80 to 98 parts by weight, based on 100 parts by weight of the granular flame retardant composition. When the content of the bromine-containing organic compound (A) is within the above range, there is an advantage that the flame retardancy of the thermoplastic resin is superior even when the amount of the granular flame retardant composition added is relatively small.

[0021] From the viewpoint of improving productivity and strength, the content of the bromine-containing organic compound (A1) is preferably 20 to 99% by weight, more preferably 40 to 97% by weight, even more preferably 60 to 95% by weight, still more preferably 80 to 93% by weight, and even more preferably 86 to 92% by weight, of the total granular flame retardant composition.

[0022] From the viewpoint of improving productivity and strength, the content of the bromine-containing organic compound (A1) is preferably 30% by weight or more of the bromine-containing organic compound (A), more preferably 40% by weight or more, even more preferably 50% by weight or more, and still more preferably 60% by weight or more, and this ratio may be 70% by weight or more, 80% by weight or more, or 90% by weight or more.

[0023] The binder (B) of the present invention contains a fatty acid (B1) having a melting point of 40 to 90°C and 16 to 22 carbon atoms. From the viewpoints of increasing productivity and strength and reducing mutual adhesion, the melting point of the fatty acid (B1) is more preferably 50 to 80°C, more preferably 55 to 75°C, and even more preferably 60 to 72°C. Furthermore, from the viewpoints of increasing productivity and strength and reducing mutual adhesion, the number of carbon atoms contained in the fatty acid (B1) is more preferably 16 to 20, and even more preferably 16 to 18. Here, the melting point of the fatty acid (B1) is the melting point measured in accordance with JIS K0064.

[0024] Examples of fatty acids (B1) include palmitic acid, stearic acid, arachidic acid, behenic acid, 2-hydroxypalmitic acid, 10-hydroxypalmitic acid, 12-hydroxystearic acid, 2-hydroxyarachidic acid, and 2-hydroxybehenic acid. Of these, stearic acid and palmitic acid are preferred from the viewpoints of increasing productivity and strength and reducing mutual adhesion. These may be used alone or in combination of two or more.

[0025] From the viewpoints of increasing productivity and strength and reducing mutual adhesion, the content of fatty acid (B1) is preferably 1 to 20% by weight, more preferably 2 to 20% by weight, more preferably 4 to 15 parts by weight, more preferably 5 to 11 parts by weight, and even more preferably 6 to 8 parts by weight, of the total granular flame retardant composition.

[0026] From the viewpoints of increasing productivity and strength and reducing mutual adhesion, the content of the fatty acid (B1) in the binder (B) is preferably 20 to 100% by weight, more preferably 40 to 100% by weight, even more preferably 60 to 100% by weight, and still more preferably 65 to 100% by weight.

[0027] From the viewpoint of increasing productivity and strength and reducing mutual adhesion, the content of the binder (B) of the present invention is preferably 1 to 20% by weight, more preferably 3 to 20% by weight, more preferably 5 to 15% by weight, and even more preferably 6 to 10% by weight of the total granular flame retardant composition.

[0028] The binder (B) of the present invention may contain a binder (B2) other than the fatty acid (B1). Examples of such a compound include an ethylene-vinyl acetate copolymer and an acrylic resin.

[0029] The weight ratio (A1 / B1) of the bromine-containing organic compound (A1) to the fatty acid (B1) is preferably 0.5 to 50, more preferably 1 to 40, more preferably 2 to 35, still more preferably 5 to 30, and even more preferably 8 to 20, from the viewpoints of increasing productivity and strength and reducing mutual adhesion.

[0030] The amount of the bromine-containing organic compound (A1-1) contained in the bromine-containing organic compound (A1) is preferably 30% by weight or more, more preferably 40% by weight or more, and even more preferably 50% by weight or more, from the viewpoints of increasing productivity and strength and reducing mutual adhesion.

[0031] The granular flame retardant composition of the present invention may further contain a stabilizer (C). Specifically, the stabilizer (C) is, for example, a heat stabilizer that improves the durability of the thermoplastic resin.

[0032] Examples of such stabilizers (C) include phosphite compounds, thioether compounds, hindered phenol compounds, hindered amine compounds, tin compounds, natural minerals, and synthetic minerals.

[0033] Examples of the phosphite compound include tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, tetrakis(2,4-di-t-butylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonite, bis(nonylphenyl)pentaerythritol diphosphite, bisstearylpentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyl) hexatridecyl-1,1,3-tris(3-t-butyl-6-methyl-4-oxyphenyl)-3-methylpropane triphosphite, mono(dinonylphenyl)mono-p-nonylphenyl phosphite, tris(mononylphenyl)phosphite, tetraalkyl(C=12-16)-4,4'-isopropylidene-(bisphenyl)diphosphite, mono- or diphenyl mono- or dialkyl (or alkoxyalkyl, C=8-13) phosphite, diphenyl isodecyl phosphite, trisdecyl phosphite, triphenyl phosphite, and the like. Examples of thioether compounds include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythryltetrakis(3-laurylthiopropionate), ditridecyl-3,3'-thiodipropionate, and 2-mercaptobenzimidazole.

[0034] Examples of hindered phenol compounds include 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], glycerin tris[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], Octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, Calcium diethyl bis[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 3,3',3",5,5',5"-hexa-t-butyl-a,a',a"-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-t-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-t-butyl-4- hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-t-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-t-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, and the like.Examples of the hindered amine compound include 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperilidinyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate, tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylate, and tetrakis(1,2,2,6,6-pentamethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylate.

[0035] Examples of tin compounds include dioctyltin dilaurate and dioctyltin maleate.

[0036] Examples of natural or synthetic minerals include hydrotalcite and zeolite.

[0037] The content of the stabilizer (C) is preferably 0.1 to 20 parts by weight, more preferably 0.3 to 15 parts by weight, and even more preferably 0.8 to 10 parts by weight, based on 100 parts by weight of the granular flame retardant composition.

[0038] The granular flame retardant composition of the present invention may further contain a phosphoric acid ester (D). Examples of such phosphoric acid esters include triphenyl phosphate, tricresyl phosphate, and trixylenyl phosphate.

[0039] The granular flame retardant composition of the present invention may contain conventionally known additives as long as the additives do not impair the effects of the present invention. Examples of such additives include fatty acid amides, fatty acids, waxes, pigments, etc. The fatty acids are, for example, fatty acids other than the fatty acid (B1).

[0040] Examples of fatty acid amides include fatty acid monoamides such as caprylic acid amide, capric acid amide, myristic acid amide, palmitic acid amide, lauric acid amide, erucic acid amide, stearic acid amide, arachidinamide, behenic acid amide, lignoceric acid amide, stearic acid monoethanolamide, oleic acid amide, linoleic acid amide, and arachidonic acid amide, ethylene biscaprylic acid amide, butylene biscaprylic acid amide, hexamethylene biscaprylic acid amide, m-xylylene biscaprylic acid amide, ethylene biscapric acid amide, butylene biscapric acid amide, hexamethylene biscapric acid amide, m-xylylene biscapric acid amide, ethylene bislauric acid amide, butylene bislauric acid amide, hexamethylene bislauric acid amide, m-xylylene bislauric acid amide, ethylene bisstearic acid amide, butylene bisstearic acid amide, hexamethylene bisstearic acid amide, m-xylylene bisstearic acid Amides, ethylene bisarachidic acid amide, butylene bisarachidic acid amide, hexamethylene bisarachidic acid amide, m-xylylene bisarachidic acid amide, ethylene bisbehenic acid amide, butylene bisbehenic acid amide, hexamethylene bisbehenic acid amide, m-xylylene bisbehenic acid amide, ethylene bislignoceric acid amide, butylene bisoleic acid amide, hexamethylene bislignoceric acid amide, m-xylylene bislignoceric acid amide, ethylene bisoleic acid amide and fatty acid bisamides such as linoleic acid amide, butylene bisoleic acid amide, hexamethylene bisoleic acid amide, m-xylylene bisoleic acid amide, ethylene bislinoleic acid amide, butylene bislinoleic acid amide, hexamethylene bislinoleic acid amide, m-xylylene bislinoleic acid amide, ethylene bisarachidonic acid amide, butylene bisarachidonic acid amide, hexamethylene bisarachidonic acid amide, and m-xylylene bisarachidonic acid amide.

[0041] Examples of fatty acids other than the fatty acid (B1) that can be used as additives include lauric acid, myristic acid, lignoceric acid, and oleic acid.

[0042] The thermoplastic resin composition of the present invention contains a granular flame retardant composition and a thermoplastic resin. The thermoplastic resin is not particularly limited, and various resins such as polystyrene resin, ABS resin, and polyurethane resin can be used. The thermoplastic resin is preferably polystyrene resin. The thermoplastic resin composition containing polystyrene resin may be foamed or non-foamed.

[0043] The granular flame retardant composition of the present invention can be obtained, for example, by mixing the bromine-containing organic compound (A), the binder (B), and, if necessary, other compounds, and kneading the mixture using a conventionally known extrusion granulator or kneading granulator, for example, at 40 to 80° C. Examples of extrusion granulators include screw-type extrusion granulators, roll-type extrusion granulators, blade-type extrusion granulators, tablet-type extrusion granulators, and briquette-type extrusion granulators.

[0044] The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto. Those skilled in the art may make various changes, modifications, and alterations without departing from the scope of the present invention.

[0045] The raw materials for producing the granular flame retardant composition will be described in detail below.

[0046] <Raw Materials Used> [Bromine-Containing Organic Compounds (A1)] (A1-1): Tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether) (trade name: Pyroguard SR-130, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., bromine content: 66% by weight) (A1-2): Tetrabromobisphenol-A-bis(2,3-dibromopropyl ether) (trade name: Pyroguard SR-720N, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., bromine content: 67% by weight)

[0047] [Bromine-containing organic compounds (A2)] (A2-1): 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (trade name: Pyroguard SR-245, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., bromine content: 67% by weight) (A2-2): tris(2,3-dibromopropyl)isocyanurate (trade name: Pyroguard SR-750, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., bromine content: 65% by weight) (A2-3): tris(tribromoneopentyl)phosphate (trade name: CR-900, manufactured by Daihachi Chemical Industry Co., Ltd., bromine content: 73% by weight)

[0048] [Fatty acids (B1)] (B1-1): Stearic acid (trade name: Stearic acid 98, manufactured by Miyoshi Oil & Fats Co., Ltd., melting point 68°C, number of carbon atoms 18) (B1-2): Palmitic acid (trade name: Palmitic acid 98, manufactured by Miyoshi Oil & Fats Co., Ltd., melting point 61°C, number of carbon atoms 16) (B1-3): Arachidic acid (trade name: Arachidic acid, manufactured by Tokyo Chemical Industry Co., Ltd., melting point 77°C, number of carbon atoms 20) (B1-4): Behenic acid (trade name: Behenic acid 85, manufactured by Miyoshi Oil & Fats Co., Ltd., melting point 76°C, number of carbon atoms 22) (b1-1): Lauric acid (trade name: Lauric acid 98, manufactured by Miyoshi Oil & Fats Co., Ltd., melting point 43°C, number of carbon atoms 12) (Comparative material) (b1-2): Myristic acid (trade name: Myristic acid 98, manufactured by Miyoshi Oil & Fats Co., Ltd., melting point 53°C, number of carbon atoms 14) (Comparative material) (b1-3): Oleic acid (trade name: Oleic acid D-100, manufactured by New Japan Chemical Co., Ltd., melting point 17°C, carbon number 18) (comparative material) (b1-4): Lignoceric acid (trade name: Lignoceric acid, manufactured by Tokyo Chemical Industry Co., Ltd., melting point 84°C, carbon number 24) (comparative material)

[0049] [Binders (B2) other than fatty acids (B1)] (B2-1): Ethylene-vinyl acetate copolymer (trade name: Ultrathene 684, manufactured by Tosoh Corporation, VA (vinyl acetate) = 20 mol%, MI (melt index) = 2000) (B2-2): Ethylene-vinyl acetate copolymer (trade name: Ultrathene 735, manufactured by Tosoh Corporation, VA = 28 mol%, MI = 1000) (B2-3): Ethylene-vinyl acetate copolymer (trade name: Ultrathene 720, manufactured by Tosoh Corporation, VA = 28 mol%, MI = 150) (B2-4): Ethylene-vinyl acetate copolymer (trade name: Ultrathene 760, manufactured by Tosoh Corporation, VA = 42 mol%, MI = 70) (B2-5): Ethylene-ethyl methacrylate copolymer (trade name: NUC-6940, manufactured by ENEOS Corporation, EA (ethyl methacrylate) = 35 mol%, MI = 20) (B2-6): Ethylene-methyl methacrylate copolymer (trade name: Acryft CM5021, manufactured by Sumitomo Chemical Co., Ltd., MMA (methyl methacrylate) = 28 mol%, MI = 450) (B2-7): Ethylene-methacrylic acid copolymer (trade name: Nucrel N0200H, manufactured by Mitsui-Dow Polychemicals Co., Ltd., MA (methacrylic acid) = 2 mol%, MI = 130)

[0050] [Stabilizers (C)] (C-1): Tris(2,4-di-t-butylphenyl)phosphite (trade name: Adekastab 2112, manufactured by ADEKA Corporation) (C-2): Tetrakis(2,2,6,6-tetramethyl-4-piperidinyl)-1,2,3,4-butanetetracarboxylate (trade name: Adekastab LA-57, manufactured by ADEKA Corporation) (C-3): Distearyl-3,3'-thiodipropionate (trade name: Lasmit SG, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) (C-4): Pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (trade name: IRGANOX 1010, manufactured by BASF) (C-5): Dioctyltin dilaurate (trade name: OL-1, manufactured by Tokyo Fine Chemical Co., Ltd.) (C-6): Hydrotalcite (product name: STABIACE HT-1, manufactured by Sakai Chemical Industry Co., Ltd.)

[0051] [Phosphate ester (D)] (D-1): Triphenyl phosphate (trade name: TPP, manufactured by Daihachi Chemical Industry Co., Ltd.)

[0052] <Evaluation of Granular Flame Retardant Composition> The amounts (by weight) of raw materials blended, the ratios of blended amounts, and the evaluation results for each Example and Comparative Example are shown in the table below.

[0053] According to the formulations shown in the table, the bromine-containing organic compound (A), the binder (B), and, if necessary, other compounds were mixed for 5 minutes at 600 rpm using a mixer (product name: High-Speed ​​Mixer, manufactured by Fukae Powtec Co., Ltd.). Hereinafter, the mixture obtained in this manner will also be referred to as the "evaluation composition." Using the evaluation compositions of each Example and Comparative Example, productivity, mutual adhesion, and strength were evaluated. Furthermore, the flame retardancy of the thermoplastic resin compositions obtained by adding each evaluation composition to a thermoplastic resin was evaluated.

[0054] (Productivity) Using an extrusion granulator (product name: EXDF-100, manufactured by Dalton Co., Ltd.) set at a temperature of 70° C., the composition for evaluation was used as a material to perform granulation while adjusting the discharge speed from the extrusion granulator, and the productivity of the granular flame retardant composition was determined. Specifically, the highest discharge speed (hereinafter also referred to as the "maximum discharge speed") within the range of discharge speeds at which granulation is possible was used to determine the productivity.

[0055] Here, the discharge rate is the weight of the flame retardant composition (whether granular or not) discharged from the extrusion granulator per unit time, and its unit is [kg / h]. Although there is some variation, the granular flame retardant composition obtained by granulation with the extrusion granulator is typically cylindrical, with a bottom diameter of 3 mm and a height of 5 mm (the same applies to the evaluation of mutual adhesion and strength described below). The productivity evaluation criteria are shown below. Evaluation "A" is the most productive and is preferred. Evaluation compositions with evaluation "D" were not evaluated for mutual adhesion and strength, etc., as described below. A: Granulation is possible, and the maximum discharge rate is 150 kg / h or more. B: Granulation is possible, and the maximum discharge rate is 100 kg / h or more but less than 150 kg / h. C: Granulation is possible, and the maximum discharge rate is 50 kg / h or more but less than 100 kg / h. D: Granulation is possible, but the maximum discharge rate is less than 50 kg / h, or granulation is not possible regardless of the discharge rate.

[0056] (Mutual Adhesion) The mutual adhesion of the granular flame retardant composition was determined by the following method. Specifically, using the above-mentioned extrusion granulator set at a temperature of 70°C, granulation was performed using the evaluation composition as a material. The discharge rate from the extrusion granulator at this time was the maximum discharge rate obtained in the above-mentioned productivity evaluation. A horizontal wooden board was placed 20 cm below the discharge port of the extrusion granulator, and the discharged granular flame retardant composition was piled up on the wooden board. 1 kg of the evaluation composition was used in this evaluation. The granular flame retardant composition was allowed to stand in an atmosphere at room temperature (25°C) for 30 minutes after granulation to sufficiently cool and solidify, and the mutual adhesion was evaluated using the granulated composition. The criteria for evaluating mutual adhesion are as follows. Note that a rating of "A" indicates the lowest mutual adhesion and is preferable. Furthermore, the term "separable" below means that, for example, each of the granular flame retardant compositions that have been aggregated into a mass can be broken apart without using any tools while maintaining its original shape. A: The granular flame retardant compositions are not adhered to each other at all. B: Some or all of the granular flame retardant compositions are adhered to each other but can be separated. C: Some or all of the granular flame retardant compositions are adhered to each other and cannot be separated.

[0057] (Strength) The granular flame retardant composition is required to have a strength sufficient to prevent it from easily crumbling. The strength of the granular flame retardant composition was determined by the following method. That is, using the above-mentioned extrusion granulator set at a temperature of 70°C, granulation was performed using the evaluation composition as a material. The discharge rate from the extrusion granulator at this time was the maximum discharge rate obtained in the above-mentioned productivity evaluation. 20 g of the obtained granular flame retardant composition was placed on a sieve with a mesh size of 1 mm and shaken for 10 minutes using a shaker (tap-type sieve shaker AS200tap, manufactured by Retsch Co., Ltd.), and the weight of the granular flame retardant composition remaining on the sieve was measured, and the ratio (wt%) to the weight (20 g) before the test was calculated. Using the calculated ratio, the strength of the granular flame retardant composition was evaluated according to the following criteria. Note that rating "A" is the highest and is preferable. A: 90 wt% or more B: 80 wt% or more but less than 90 wt% C: Less than 80 wt%

[0058] (Flame retardancy of thermoplastic resin composition) It was confirmed that the thermoplastic resin composition obtained by adding the granular flame retardant composition of each of the examples and comparative examples to a thermoplastic resin had flame retardancy.

[0059] Specifically, a styrene-based resin (trade name: PSJ Polystyrene G9305, manufactured by PS Japan Co., Ltd.) and a granular flame retardant composition were charged into an extruder with a bore of 65 mm, and the interior of the extruder was heated to 200°C to melt and plasticize the resin, followed by continued kneading to prepare a styrene-based resin composition in the extruder. The blending ratio of the styrene-based resin to the granular flame retardant composition was adjusted so that the bromine-containing organic compound (A) in the granular flame retardant composition accounted for 3 wt% of the total. The extruder used was a two-stage extruder connected in series with bore diameters of 65 mm to 90 mm.

[0060] Next, a predetermined amount of blowing agent was injected into the tip of the 65 mm extruder (opposite the nozzle of the 90 mm extruder) via a separate line, and the resin temperature (internal temperature) was cooled to 120°C using the 90 mm extruder. As the blowing agents, 3 parts by weight of isobutane and 3 parts by weight of dimethyl ether (per 100 parts by weight of styrene-based resin) were used. The resin composition was then extruded into the atmosphere through a die lip with a rectangular cross section measuring 2.5 mm in thickness and 45 mm in width attached to the tip of the 90 mm extruder, yielding a rectangular shaped extruded foam molded product of the styrene-based resin. The oxygen index of the resulting extruded foam molded product was measured according to JIS K-7201, and the flame retardancy of the extruded foam molded product was evaluated. The flame retardancy evaluation criteria are shown below. Note that a rating of "A" indicates higher flame retardancy and is preferable. Furthermore, products with an oxygen index of 26 or higher are not subject to the designated flammable material requirement under Japan's Fire Service Act. A: Oxygen index is 26 or more B: Oxygen index is less than 26

[0061] Here, confirmation of the flame retardancy of expanded styrene resin has been described as an example, but it was also confirmed that the thermoplastic resin composition had the desired flame retardancy when other thermoplastic resins (such as non-expanded styrene resin and ABS resin) were used.

[0062]

[0063]

[0064]

[0065] From each table, it can be seen that the granular flame retardant composition of the present invention, that is, the granular flame retardant composition shown in each example, is excellent in productivity, has low mutual adhesion, and is excellent in strength.

[0066] In this specification, for example, the expression "XX to YY" means "XX or more and YY or less."

[0067] The granular flame retardant composition of the present invention can be used as a flame retardant for thermoplastic resins.

Claims

1. A granular flame retardant composition containing a bromine-containing organic compound (A) and a binder (B), wherein the bromine-containing organic compound (A) contains at least one bromine-containing organic compound (A1) selected from the group consisting of bromine-containing organic compounds (A1-1) having a 2,3-dibromo-2-alkylpropyl group and bromine-containing organic compounds (A1-2) having a 2,3-dibromopropyl group, and the bromine-containing organic compound (A1-1) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromo-2-methylpropyl ether), tetrabromobisphenol-S-bis(2,3-dibromo-2-methylpropyl ether) and tetrabromobisphenol-F-bis(2,3-dibromo-2-methylpropyl ether), The bromine-containing organic compound (A1-2) is at least one selected from the group consisting of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-S-bis(2,3-dibromopropyl ether) and tetrabromobisphenol-F-bis(2,3-dibromopropyl ether), and the binder (B) contains a fatty acid (B1) having 16 to 22 carbon atoms and a melting point of 40 to 90° C.

2. The granular flame retardant composition according to claim 1, wherein the content of the fatty acid (B1) is 1 to 20% by weight of the granular flame retardant composition.

3. The granular flame retardant composition according to claim 1, wherein the content of the bromine-containing organic compound (A1) is 20 to 99% by weight of the granular flame retardant composition.

4. A thermoplastic resin composition comprising the granular flame retardant composition according to any one of claims 1 to 3 and a thermoplastic resin.

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