WO2009084800A1

WO2009084800A1 - Flameproof thermoplastic resin composition and method for preparing the same

Info

Publication number: WO2009084800A1
Application number: PCT/KR2008/005906
Authority: WO
Inventors: Seon Ae Lee; Sang Hyun Hong; Kyung Hoon Shin; Jin Seong Lee; Seong Ho Kong
Original assignee: Cheil Industries Inc.
Priority date: 2007-12-28
Filing date: 2008-10-08
Publication date: 2009-07-09
Also published as: US8367754B2; EP2231780A4; CN101910299B; JP5350391B2; JP2011508044A; EP2231780B1; US20110034587A1; CN101910299A; TWI393738B; EP2231780A1; TW200932817A

Abstract

A flameproof thermoplastic resin composition comprises (A) 100 parts by weight of a thermoplastic resin; (B) about l~40 parts by weight of a sublimational filler; and (C) about l~30 parts by weight of a flame retardant. The thermoplastic resin composition can solve the problems of high specific gravity and deterioration of flame retardancy caused by adding a conventional filler.

Description

FLAMEPROOF THERMOPLASTIC RESIN COMPOSITION AND METHOD FOR PREPARING THE SAME

Technical Field

[1] The present invention relates to a flameproof thermoplastic resin composition. More particularly, the present invention relates to a thermoplastic resin composition solving the problems of high specific gravity and the deterioration of flame retardancy resulting from adding a conventional filler by adding a sublimational material which sublimates at high temperature to a thermoplastic resin as a filler.

[2]

Background Art

[3] Generally, thermoplastic resins have good processability and mechanical properties such that the resins have been widely used in various products including electronic goods. Some of these thermoplastic resins have been used as flameproof resins after adding some flame retardant in order to decrease the danger of fire while using them. The most applicable and general method for imparting flame retardancy is to add halogen containing compounds or phosphorus compounds as a flame retardant to thermoplastic resins. However, since a flame retardant itself cannot provide an acceptable level of flame retardancy, a flame retardant is used together with a flame retardant aid. For example, bromine containing compounds can be used with antimony containing compounds, and phosphorus containing compounds can be used together with a char- forming agent such as polycarbonate resin or polyphenylene ether resin in order to impart flame retardancy.

[4] On the other hand, a filler is also added to reduce the cost of raw materials, in addition to improve processability. In general, examples of the filler for a thermoplastic resin include calcium carbonate, talc, silica, mica, barium sulfate, and the like. However, because the filler has a high specific gravity, the addition of the filler increases the specific gravity of the composition, the weight per volume, and eventually, the weight of the molded articles. Therefore, the addition of the filler can significantly undermine the cost reducing effect of the filler.

[5] Furthermore, when a filler is added to a resin, it markedly lowers flame retardancy such that it is difficult to obtain a desirable flame retardancy in a flameproof resin.

[6] Accordingly, in order to prevent high specific gravity and deterioration of flame retardancy which are caused by addition of a filler to a flameproof resin, the present inventors have developed a flameproof resin composition having low specific gravity and good flame retardancy by adding a sublimational filler having low specific gravity which sublimates at high temperature. [7]

Disclosure of Invention

Technical Problem [8] An object of the present invention is to provide a thermoplastic resin composition having excellent flame retardancy and stability against fire. [9] Another object of the present invention is to provide thermoplastic resin composition having low specific gravity by adding a sublimational filler which sublimates at high temperature to prevent high specific gravity and deterioration of flame retardancy caused by addition of a filler to a flameproof resin. [10] Another object of the present invention is to provide a thermoplastic resin composition having good flame retardancy and impact resistance as well as low specific gravity. [11] Another object of the present invention is to provide a thermoplastic resin composition which can increase processability and reduce the cost of raw materials. [12] Another object of the present invention is to provide molded articles having good flame retardancy and low specific gravity by using the above flameproof thermoplastic resin composition.

[13] Another object of the present invention is to provide a method for preparing a thermoplastic resin composition having good flame retardancy by adding a filler which sublimates at high temperature. [14] Another object of the present invention is to provide a method for improving flame retardancy by using the sublimational filler. [15] Other objects and advantages of this invention will be apparent from the ensuing disclosure and appended claims. [16]

Technical Solution [17] An aspect of the present invention provides a flameproof thermoplastic resin composition. The resin composition comprises (A) 100 parts by weight of a thermoplastic resin; (B) about l~40 parts by weight of a sublimational filler; and (C) about l~30 parts by weight of a flame retardant. [18] In some exemplary embodiments, the thermoplastic resin (A) may include an aromatic vinyl resin, a rubber modified aromatic vinyl resin, a polyphenylene ether resin, a polycarbonate resin, a polyester resin, a methacrylate resin, a polyaryle- nesulfide resin, a polyamide resin, a polyvinylchloride resin, a polyolefin resin and the like. In an exemplary embodiment, the thermoplastic resin (A) may comprise about 50~90 % by weight of an aromatic vinyl resin and about 10~50 % by weight of a polyphenylene ether resin.

[19] The sublimational filler (B) which has a sublimation temperature of about 200~500

⁰C may be used. Additionally, the sublimational filler (B) which has an average particle diameter of about l~150 μm may be used, in which 90 % of the total volume fraction has an average particle diameter of about l~20 μm.

[20] The sublimational filler (B) may include terephthalic acid, isophthalic acid or a mixture thereof

[21] The flame retardant (C) may be a phosphorus -containing flame retardant. Examples of the phosphorous-containing flame retardants may include red phosphorus, phosphate, phosphonate, phosphinate, phosphine oxide, phosphazene, a metal salt thereof, and the like. These may be used alone or in combination with one another.

[22] The flame retardant may be a halogen-containing flame retardant. Examples of the halogen-containing flame retardant may include decabromo diphenyl oxide, decabromo diphenyl ethane, decabromodiphenyl ether, tetrabromo bisphenol A, tetrabromo bisphenol A-epoxy oligomer, brominated epoxy oligomer, octabromo trimethylphenyl phosphate, ethylene bistetrabromophthalimide, 2,4,6-tris (2,4,6-tribromophenoxy)- 1 ,3,5-triazine, l,2,3,4,7,8,9,10,13,13,14-dodecachloro-l,4,4a,5,6,6a,7,10,10a,l l,12,12a-dodecahydro- 1,4,7, 10-dimethanodibenzo(a,e) cyclooctene, and the like. These may be used alone or in combination with one another.

[23] In an exemplary embodiment, the flameproof thermoplastic resin composition may further comprise antimony oxide together with the halogen-containing flame retardant. The antimony oxide may be used in an amount of l~10 parts by weight per 100 parts by weight of a thermoplastic resin. In another exemplary embodiment, the flameproof thermoplastic resin composition may further comprise antimony oxide together with the phosphorus -containing flame retardant.

[24] The resin composition of the present invention may further comprise other additives such as flame retardant aids, plasticizers, heat stabilizers, anti-dripping agents, antioxidants, compatibilizers, light-stabilizers, releasing agents, lubricants, impact modifiers, coupling agents, antistatic agents, dispersant, weather resistant agents, pigments, dyes, inorganic fillers and the like.

[25] Another aspect of the present invention provides a molded article produced by using the thermoplastic resin composition. The molded article may be prepared by extruding the flameproof thermoplastic resin composition. The molded article may have a specific gravity of about 1.1 to 1.5 measured in accordance with ASTM D792 and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12". In another embodiment, the molded article may have an Izod impact strength of about 6.8 to about 15 kgf-cm/cm measured in accordance with ASTM-D256 at a thickness of 1/8" at 23 ⁰C and a specific gravity of about 1.1 to 1.5 measured in accordance with ASTM D792, and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12".

[26] Another aspect of the present invention provides a method for preparing a flameproof thermoplastic resin composition. The method comprises extruding a thermoplastic resin composition at 120~280 ⁰C which includes 100 parts by weight of a thermoplastic resin, about l~40 parts by weight of a sublimational filler, and about l~30 parts by weight of a flame retardant.

[27] Another aspect of the present invention provides a method for improving flame retardancy by adding a sublimational filler having a sublimation temperature of about 200~500 ⁰C to a flameproof resin which comprises a thermoplastic resin and a flame retardant.

[28] The present invention now will be described more fully hereinafter in the following detailed description of the invention.

[29]

Best Mode for Carrying Out the Invention

[30] (A) Thermoplastic resin

[31] The thermoplastic resin suitable for use in the present invention can be without limitation any thermoplastic resin. Examples of the thermoplastic resin may include, but are not limited to, an aromatic vinyl resin, a rubber modified aromatic vinyl resin, a polyphenylene ether resin, a polycarbonate resin, a polyester resin, a methacrylate resin, a polyarylenesulfide resin, a polyamide resin, a polyvinylchloride resin, a poljolefin resin, and the like. The thermoplastic resin can be used alone or in combination with one another.

[32] In an exemplary embodiment, the thermoplastic resin may comprise a polymer having a weight average molecular weight of about 10,000 or more.

[33] The aromatic vinyl resin may include a homopolymer of an aromatic vinyl monomer or a rubber modified aromatic vinyl resin of an aromatic vinyl monomer and rubbery polymer. The rubber modified aromatic vinyl resin may be prepared by polymerizing an aromatic vinyl monomer and rubbery polymer. Examples of the rubbery polymer may include without limitation butadiene rubbers, isoprene rubbers, styrene/butadiene rubbers, acrylic rubbers such as alkylacrylate, ethylene-propylene-diene terpolymer (EPDM), ethylene/propylene rubbers, silicon rubbers, and the like. The rubbery polymer may be used alone or in combination with one another. Furthermore, the rubbery polymer may have a particle size of about 0.1 to about 4 μm. The rubbery polymer may be used in an amount of about 3~30 % by weight, preferably about 5~15 % by weight.

[34] The aromatic vinyl monomer may be used in an amount of about 70 to 97 % by weight, preferably about 85 to 95 % by weight. Examples of the aromatic vinyl monomer may include styrene, α-methyl styrene, vinyl toluene, and the like. These may be used alone or in combination with one another.

[35] In addition, other monomers copolymerizable with the aromatic vinyl monomer can be used. Examples of the monomers copolymerizable with the aromatic vinyl monomer may include acrylonitrile, methacrylonitrile, alkyl(meth)acrylate, acrylic acid, methacrylic acid, maleic anhydride, N-substituted maleimide, epoxy-containing monomer, and the like. These monomers may be used alone or in combination with one another. The amount of copolymerizable monomers used may be in a range of about 40 % by weight or less, preferably about 0.01~40 % by weight, more preferably about 0.1 ~25 % by weight, per total aromatic vinyl resin.

[36] In some exemplary embodiments, examples of the aromatic vinyl resin may include

GPPS, sPS, HIPS, ABS, ASA, SAN, MSAN, MABS, and the like. These resins can be used alone or in combination with one another.

[37] The polyphenylene ether resin may be added to improve flame retardancy and thermal resistancy. Examples of the polyphenylene ether resin may include poly(2,6-dimethyl-l,4-phenylene) ether, poly(2,6-diethyl-l,4-phenylene) ether, poly(2,6-dipropyl-l,4-phenylene) ether, poly(2-methyl-6-ethyl-l,4-phenylene) ether, poly(2-methyl-6-propyl-l,4-phenylene) ether, poly(2-ethyl-6-propyl-l,4-phenylene) ether, poly(2,6-diphenyl-l,4-phenylene) ether, copolymer of poly(2,6-dimethyl-l,4-phenylene) ether and poly(2,3,6-trimethyl-l,4-phenylene) ether, and copolymer of poly(2,6-dimethyl-l,4-phenylene) ether and poly(2,3,5-triethyl-l,4-phenylene) ether. Although the degree of polymerization of the polyphenylene ether is not limited, inherent viscosity measured in chloroform solution at 25 ⁰C is preferably about 0.2~0.8, considering thermal stability and workability of the resin composition.

[38] As for the thermoplastic resin, a polycarbonate resin having a weight average molecular weight of about 10,000 to 200,000 can be used. The polycarbonate resin may include homopolymers using one type of dihydric phenol compounds, or copolymers or mixtures thereof using at least two types of dihydric phenol compounds. Further, linear polycarbonate resin, branched polycarbonate resin or polyester- carbonate copolymer resin can be used.

[39] The thermoplastic resin may also include terephthalic acid ester resin such as polyethylene terephthalate and polybutylene terephthalate.

[40] The thermoplastic resin of the present invention may be methacrylic resin. The methacrylic resin is a copolymer comprising about 50 to 100 % by weight of methyl- methacrylate (MMA) and about 0 to 50 % by weight of a mono-functional unsaturated monomer. Examples of the mono-functional unsaturated monomer may be a copoly- merizable monomer and may include without limitation methacrylate monomers such as ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, phenyl methacrylate, and glycidyl methacrylate; acrylate monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; unsaturated carboxylic acid monomers such as methacrylic acid; acid anhydride monomers such as maleic anhydride, and mono-functional vinyl containing monomers such as styrene, acrylonitrile, and methacrylonitrile; and the like. These monomers may be used alone or in combination with one another.

[41] In another exemplary embodiment, the thermoplastic resin may be a polyolefin resin.

The polyolefin resin may include polyethylene, polypropylene, and the like. The polyolefin may also be used as modified with a glycidyl group or a (meth) acrylate group. The polyethylene can be any form such as HDPE, LDPE, and LLDPE, and it can have any structure such as atactic, syndiotactic, isotactic, and the like. The polyolefin resin may be copolymerized with monomers having other ethylene -based unsaturated groups.

[42] The thermoplastic resin of the present invention may not be limited to the aforementioned resins, and may be an alloy prepared by blending alone or in combination with one another. In an exemplary embodiment, the thermoplastic resin may comprise about 50~90 % by weight of an aromatic vinyl resin and about 10~50 % by weight of a polyphenylene ether resin. In another exemplary embodiment, the thermoplastic resin may comprise about 50~90 % by weight of a rubber modified aromatic vinyl resin and about 10-50 % by weight of a polyphenylene ether resin. In other exemplary embodiments, the thermoplastic resin may comprise about 60-90 % by weight of a polycarbonate resin and about 10-40 % by weight of a rubber modified aromatic vinyl resin polyphenylene ether resin. In other exemplary embodiments, the thermoplastic resin may comprise about 55-90 % by weight of a polycarbonate resin and about 10-45 % by weight of a methacrylate resin.

[43]

[44] (B) Sublimational filler

[45] The sublimational filler sublimates at high temperatures and absorbs combustion heat generated while combusting, otherwise the combustion heat can cause products obtained after decomposition of resin to be burned. This characteristic results in good flame retardancy. Since the phase of the sublimational filler changes directly from solid to gas as temperature increases, compared to general materials which change from solid to liquid and then to gas, the sublimational filler can absorb a considerable amount of heat during the phase change.

[46] Generally, sublimational materials may include dry ice, iodine, naphthalene, benzoic acid, isophthalic acid, terephthalic acid, and the like. Among these, sublimational materials having a low sublimation temperature may not be applicable for a flameproof resin since the material can sublimate at room temperature and during the production process of a polymer. Accordingly, in the present invention, materials having a sublimation temperature of about 200 ⁰C or more may be used, preferably about 210-500 ⁰C, more preferably about 250-500 ⁰C, most preferably about 290-500 ⁰C. In some exemplary embodiments, sublimational fillers may include terephthalic acid, isophthalic acid, and the like. These fillers may be used alone or in combination with one another.

[47] In exemplary embodiments, terephthalic acid which has a sublimation temperature of about 300 ⁰C, sublimation heat about 139 kJ/mol, and a melting temperature of about 450 ⁰C can be used. The terephthalic acid can be added to resins in a solid state which can remain stable during the production processes such as extrusion and injection, since the sublimation temperature of the terephthalic acid is about 300 ⁰C. Furthermore, the sublimational filler can absorb heat of about 139 kJ/mol at about 300 0C, during combustion. In a general combustion process, combustion heat plays a role in the supply of fuel gas which can decompose a polymer resin. In contrast, terephthalic acid can prevent combustible fuel gas from decomposing the polymer resin by absorbing the combustion heat. The sublimation heat of terephthalic acid is about a half of the absorption heat of aluminum hydroxide which is widely used as a poljolefin containing flame retardant and which has an absorption heat of about 298 kJ/mol. In addition, the sublimation temperature of terephthalic acid is higher than the decomposition temperature of aluminum hydroxide which ranges about 180~200 ⁰C so that it is possible to obtain good appearance despite being subjected to a production process such as extrusion and injection, and that it is suitable for products having a high processing heat.

[48] The sublimational filler suitable for use in the present invention may have an average particle diameter of about l~150 μm, preferably about l~50 μm, more preferably about l~20 μm, most preferably about l~10 μm. In an exemplary embodiment, 90 % of the total volume fraction may have a particle diameter of about l~120 μm, about l~100 μm, or about 1~95 μm. In another exemplary embodiment, 90 % of the total volume fraction may have a particle diameter of about l~20 μm, about 1 — 15 μm or about 1 — 13 μm.

[49] In the present invention, the sublimational filler (B) may be used in an amount of about l~40 parts by weight, preferably about 3~30 parts by weight, more preferably about 3~20 parts by weight, most preferably about 3~15 per 100 parts by weight of a thermoplastic resin. If the amount of the sublimational filler is less than about 1 part by weight, the combustion heat absorption effect may be decreased, and if the amount of the sublimational filler is more than about 40 parts by weight, the mechanical properties may be deteriorated.

[50]

[51] (C) Flame retardant

[52] In an exemplary embodiment, the flame retardant may be a phosphorus-containing flame retardant. Examples of the phosphorus-containing flame retardant may include, but are not limited to, red phosphorus, phosphate, phosphonate, phosphinate, phosphine oxide, phosphazene, a metal salt thereof, and the like. These can be used alone or in combination with one another.

[53] In an exemplary embodiment, the phosphorus-containing flame retardant may be phosphate. The phosphate is an aromatic phosphoric ester compound represented by the following Chemical Formula 1.

[54]

[55] [Chemical Formula 1]

[57] wherein R , R , and R are independently hydrogen or a C -C alkyl group; X is a C -

C aarryyll g grroouupp oorr aann aallkkyyll--ssuubbssttiittuutteedd CC --CC aarryyll group derived from resorcinol, hy-

2200 66 2200 droquinol, and bisphenol-A; and n is about 0~4.

[58] [59] When n is 0, the compounds represented in the Chemical Formula 1 include triphenyl phosphate, tri(2,6-dimethyl) phosphate, and the like. When n is 1, the compounds include resorcinol bis(diphenyl) phosphate, resorcinol bis(2,6-dimethyl phenyl) phosphate, resorcinol bis(2,4-ditertiary butyl phenyl) phosphate, hydroquinol bis(2,6-dimethyl phenyl) phosphate, hydroquinol bis(2,4-ditertiary butyl phenyl) phosphate, and the like. The aromatic phosphate ester compounds can be used alone or in combination therewith.

[60] In some exemplary embodiments, the flame retardant may be a halogen containing flame retardant. The halogen containing flame retardant may be a bromide containing flame retardant or a chloride containing flame retardant. Preferably, a halogen containing flame retardant including chloride or bromide in an amount of 50 % or more may be used, taking into account the desired mechanical properties and flame retardancy. Examples of the halogen-containing flame retardant may include decabromo diphenyl oxide, decabromo diphenyl ethane, decabromodiphenylether, tetrabromo bis phenol A, tetrabromo bis phenol A-epoxy oligomer, brominated epoxy oligomer, octabromo trimethylphenyl phosphate, ethylene bistetrabromophthalimide, 2,4,6-tris(2,4,6-tribromophenoxy)-l,3,5-triazine, l,2,3,4,7,8,9,10,13,13,14-dodecachloro-l,4,4a,5,6,6a,7,10,10a,l l,12,12a-dodecahydro- 1,4,7, 10-dimethanodibenzo(a,e) cyclooctene, and the like. These can be used alone or in combination with one another.

[61] The flame retardant of the present invention may be used in an amount of about 1 part by weight to 30 parts by weight, preferably about 5 to 27 parts by weight, more preferably about 10 to 25 parts by weight. If the amount is more than about 30 parts by weight, impact strength may be deteriorated.

[62] In some exemplary embodiments, flame retardant aids may be used together with the flame retardant. In an exemplary embodiment, antimony oxide may be used as a flame retardant aid together with the halogen containing flame retardant. In another exemplary embodiment, antimony oxide may be used together with the phosphorus containing flame retardant. The antimony oxide may include antimony trioxide, antimony pentoxide, or a mixture thereof In an exemplary embodiment, the antimony oxide having antimony in an amount of about 75~90 % by weight may be used. The antimony trioxide may have a 50 cumulative percent particle size of 0.01~6 μm, preferably 0.02~3.0 μm, and the antimony pentoxide may have a 50 cumulative percent particle size of 0.01~ 1.0 μm, preferably 0.02~0.5 μm. The antimony oxide may be used in an amount of l~10 parts by weight, preferably 2.5~7 parts by weight per 100 parts by weight of a thermoplastic resin. If the amount of the antimony oxide is more than 10 parts by weight, the balance of physical properties of the resin may be deteriorated.

[63] The thermoplastic resin composition of the present invention may further comprise other additives such as plasticizers, heat stabilizers, anti-dripping agents, antioxidants, compatibilizers, light-stabilizers, releasing agents, lubricants, impact modifiers, coupling agents, antistatic agents, dispersant, weather resistant agents, pigments, dyes, inorganic fillers and the like. These additives may be used alone or in combination with one another. The additives may be used in an amount of about 0.01 to 30 parts by weight per 100 parts by weight of a thermoplastic resin. Examples of the inorganic fillers may include without limitation glass fibers, talc, ceramic, and sulfates.

[64] Another aspect of the present invention provides a method for preparing a flameproof thermoplastic resin composition. The method may comprise extruding a thermoplastic resin composition at about 120~280 ⁰C which includes 100 parts by weight of a thermoplastic resin, about l~40 parts by weight of a sublimational filler, and about l~30 parts by weight of a flame retardant. In an exemplary embodiment, the extrusion of the thermoplastic resin composition can be conducted at about 150 to 280 0C. In another exemplary embodiment, the extrusion can be conducted at about 180 to 250 ⁰C. Preferably, the extrusion can be conducted without limitation at a temperature lower than the sublimation temperature of the sublimational filler.

[65] The resin composition of the present invention may be prepared in pellet form by mixing the aforementioned components and selective additives in a mixer at the same time and melt-extruding the mixture through a conventional extruder. The resin pellets were molded into various molded articles using molding methods such as extrusion, injection, vacuum molding, casting molding and the like, but are not limited to these methods.

[66] Another aspect of the present invention provides molded articles produced by the resin composition. In an exemplary embodiment, the molded articles have a specific gravity of about 1.1 to 1.5 measured in accordance with ASTM D792 and flame retardancy of V-O or V-I measured in accordance with UL-94 at a thickness of 1/12". In another exemplary embodiment, the molded articles have a specific gravity of about 1.1 to 1.3 measured in accordance with ASTM D792 and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12". In other exemplary embodiments, the molded articles have an impact strength of about 6.8 to 15 kgf-cm/cm or more measured in accordance with ASTM D256 at a thickness of 1/8", a specific gravity of about 1.1 to 1.5 measured in accordance with ASTM D792, and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12".

[67] The molded articles of the present invention may be suitable for precision parts of automobiles, structural materials, interior goods, electrical and electronic goods such as TV housings, computers, audio sets, and air conditioners, housings for office automation devices, and the like, in addition to small household and personal items/ amenities, since the molded articles have excellent mechanical properties, flame retardancy, processability, and a low specific gravity.

[68] The invention may be better understood by reference to the following examples which are intended for the purpose of illustration and are not to be construed as in any way limiting the scope of the present invention, which is defined in the claims appended hereto.

[69]

Mode for the Invention

[70] Examples

[71]

[72] Application of phosphorus containing flame retardant

[73] The specifications of components used in Examples 1~12 and Comparative

Examples 1~3 will be described more fully hereinafter.

[74]

[75] (A) Thermoplastic resin

[76] (al) HIPS: HIPS resin (product name: HG- 17605) manufactured by Cheil Industries

Inc. of South Korea was used.

[77] (a2) ABS: g-Aa2S manufactured by Cheil Industries Inc. of South Korea was used. [78] (a3) Polyphenylene ether resin: poly(2,6-dimethyl-phenylether) (product name: PX-

100F) manufactured by Mitsubishi Engineering Plastics was used.

[79] (a4) Polycarbonate resin: bisphenol-A type linear polycarbonate resin manufactured by TEIJIN Go. of Japan (PANLITE L-1250WP) having a weight average molecular weight of 25,000 g/mol was used.

[80] (a5) PMMA resin: PMMA IH 830 Grade manufactured by LG Chem, Ltd. of South

Korea was used.

[81]

[82] (B) Sublimational filler: a product having an average particle size of 3 μm obtained from pulverizing purified terephthalic acid with an average particle diameter of 50 μm manufactured by SK Chemicals Go., Ltd. of South Korea was used.

[83]

[84] (C) Phosphorus-containing flame retardant: bisphenol A bis (diphenyl)phosphate manufactured by Daihachi Gompany of Japan (product name: CR741S) was used.

[85]

[86] Examples 1-9

[87]

[88] The components as shown in Table 1 were mixed in a conventional mixer and the mixture was extruded at 200~280 ⁰C through a conventional twin screw extruder into pellets. The resin pellets were then dried at 80 ⁰C for 2 hours and molded into test specimens for evaluation of physical properties and flame retardancy using a 10-oz injection molding machine at 180~260 ⁰C with a barrel temperature of 40~80 ⁰C. Thereafter, the flame retardancy was measured for the specimens in accordance with UL-94 VB regulations at a thickness of 1/12", and the specific gravity was measured in accordance with ASTM D792.

[89]

[90] Table 1

[Table 1] [Table ]

[91] [92] Comparative Examples 1~3 [93] [94] Comparative Example 1 was conducted in the same manner as in Example 1 except the sublimational filler was not added. Comparative Example 2 was conducted in the same manner as in Example 4 except the sublimational filler was not added. Comparative Example 3 was conducted in the same manner as in Example 7 except the sublimational filler was not added. The results of the physical properties and input amount of components in Examples and Comparative Examples are shown in Tables 2, 3, and 4.

[95] [96] Table 2 [Table 2] [Table ]

[97] [98] Table 3

[Table 3] [Table ]

[99] [100] Table 4

[Table 4] [Table ]

[101] [102] As shown in Tables 1~4, when a sublimational filler is added, it can be seen that both good flame retardancy and low specific gravity were exhibited.

[103] [104] Examples 10~12 [105] [106] Examples 10~12 were conducted in the same manner as in Example 1 except polypropylene, polyamide, and polyethyleneterephthalate were used respectively in an amount of 100 parts by weight as a thermoplastic resin. It can be seen that a flame retardancy of V-I or more and a specific gravity of 1.1 to 1.5 were exhibited.

[107] [108] Application of halogen containing flame retardant [109] Each component used in Examples 1~12 and Comparative Examples 1~3 is as follows.

[HO] (A) Thermoplastic resin [111] (al) HIPS-I: HIPS (product name: HG1760S) manufectured by Cheil Industries Inc. of South Korea was used. [112] (a2) HIPS-2: HIPS (product name: HG 1690H) manufactured by Cheil Industries Inc. of South Korea was used. [113] (a3) ABS: ABS (product name: HR5330) manufactured by Cheil Industries Inc. of South Korea was used.

[114] [115] (B) Sublimational filler [116] F-I: purified terephthalic acid having an average particle diameter of 50 μm manufactured by SK Chemicals Go., Ltd. was used.

[117] F-2: F-2 was obtained by pulverizing F-I to have an average particle diameter of 5 μm. [118] Particle size distribution of purified terephthalic acid used is represented in the following Table 5.

[119] [120] Table 5 [Table 5] [Table ]

[121] F-3: talc, UPN HS-T 0.5 (manufactured by Hayashi G)., Ltd.) [122] F-4: calcium carbonate, OMYA BSH (manufactured by Omya GmbH) [123] F-5: mica, MICA 20-S (manufactured by Suzorite Mica Go., Ltd.) [124] F-6: barium sulfate, BALIUM SULFATE (manufactured by Nippon Solvey G)., Ltd.)

[125] [126] (C) Halogen compound [127] HF-I: deca bromo diphenyl ethane [128] HF-2: 2,4,6-tris(2,4,6-tribromophenoxy)-l,3,5-triazine [129] HF-3: brominated epoxy oligomer, Non-Capping type. (Kukdo Chemical Go., Ltd. product name:YDB-406)

[130] HF-4: brominated epoxy oligomer, Capping type. (Kukdo Chemical Go., Ltd., product name: KB- 560)

[131] [132] (D) Antimony oxide

[133] ANTIS N, antimony trioxide manufactured by Ilsung Go., Ltd. was used.

[134]

[135] Examples 13~20 and Comparative Examples 4~12

[136]

[137] The aforementioned (A) thermoplastic resin, (B) sublimational filler, (C) halogen compound and (D) antimony oxide were mixed in the amounts as shown in Tables 6 and 7, and the mixture was extruded at 190~230 ⁰C through a conventional twin screw extruder into pellets. The resin pellets were then dried at 70 ⁰C for 3 hours and molded into test samples for evaluation of physical properties and flame retardancy using a 6-oz injection molding machine at 180~220 ⁰C with a barrel temperature of 30~50 ⁰C.

[138] Thereafter, the flame retardancy was measured for the test samples in accordance with UL-94 VB regulations at a sample thickness of 1/12", impact strength was measured in accordance with ASTM D256(l/8", notched, kgf-cm/cm), and the specific gravity was measured in accordance with ASTM D792. The results are shown in Tables 6 and 7 below.

[139]

[140] Table 6

[Table 6] [Table ]

[141] [142] Table 7

[Table 7] [Table ]

[143] [144] As shown in Tables 6 and 7, when the sublimational filler having a high sublimation temperature is added to the flameproof thermoplastic resin, it can be seen that the flameproof thermoplastic resin composition which solves a problem of high specific gravity caused by adding a conventional filler can be obtained, while maintaining good flame retardancy.

[145] In the above, the present invention was described based on the specific preferred em- bodiments, but it should be apparent to those ordinarily skilled in the art that various changes and modifications can be added without departing from the spirit and scope of the present invention which will be defined in the appended claims.

Claims

Claims[1] A flameproof thermoplastic resin composition comprising (A) 100 parts by weight of a thermoplastic resin; (B) about l~40 parts by weight of a sub- limational filler; and (C) about l~30 parts by weight of a flame retardant.[2] The flameproof thermoplastic resin composition of Claim 1, wherein said thermoplastic resin (A) is selected from the group consisting of an aromatic vinyl resin, a rubber modified aromatic vinyl resin, a polyphenylene ether resin, a polycarbonate resin, a polyester resin, a methacrylate resin, a polyarylenesulfide resin, a polyamide resin, a polyvinylchloride resin, a poljolefin resin, and a mixture thereof[3] The flameproof thermoplastic resin composition of Claim 1, wherein said sub- limational filler (B) has a sublimation temperature of about 200~500 0C.[4] The flameproof thermoplastic resin composition of Claim 1, wherein said sub- limational filler (B) has an average particle diameter of about l~150 /M, 90 % of the total volume fraction of said sublimational filler (B) having an average particle diameter of about l~20 /M.[5] The flameproof thermoplastic resin composition of Claim 1, wherein said sublimational filler (B) is terephthalic acid, isophthalic acid or a mixture thereof[6] The flameproof thermoplastic resin composition of Claim 1, wherein said flame retardant (C) is a phosphorus-containing flame retardant.[7] The flameproof thermoplastic resin composition of Claim 1, wherein said flame retardant is a halogen-containing flame retardant.[8] The flameproof thermoplastic resin composition of Claim 6, wherein said phosphorus flame retardant is at least one selected from the group consisting of red phosphorus, phosphate, phosphonate, phosphinate, phosphine oxide, phosphazene, a metal salt thereof, and a mixture thereof[9] The flameproof thermoplastic resin composition of Claim 7, wherein said halogen-containing flame retardant is at least one selected from the group consisting of decabromo diphenyl oxide, decabromo diphenyl ethane, decabro- modiphenyl ether, tetrabromo bisphenol A, tetrabromo bisphenol A-epoxy oligomer, brominated epoxy oligomer, octabromo trimethylphenyl phosphate, ethylene bistetrabromophthalimide, 2,4,6- tris( 2,4,6-tribromophenoxy)- 1 ,3,5-triazine, l,2,3,4,7,8,9,10,13,13,14-dodecachloro-l,4,4a,5,6,6a,7,10,10a,l l,12,12a-dodeca hydro-l,4,7,10-dimethanodibenzo(a,e) cyclooctene, and a mixture thereof[10] The flameproof thermoplastic resin composition of Claim 7, further comprising l~10 parts by weight of an antimony oxide. [H] The flameproof thermoplastic resin composition of Claim 8, wherein said phosphate is represented by the following Chemical Formula 1 :

[Chemical Formula 1]

wherein R , R , and R are independently hydrogen or a C -C alkyl group; X is a

3 4 5 1 4

C -C aryl group or an alkyl-substituted C -C aryl group derived from

6 20 6 20 resorcinol, hydroquinol, and bisphenol-A; and n is about 0~4.

[12] The flameproof thermoplastic resin composition of Claim 1, wherein said resin composition further comprises at least one additive selected from flame retardant aids, plasticizers, heat stabilizers, anti-dripping agents, antioxidants, compat- ibilizers, light- stabilizers, releasing agents, lubricants, impact modifiers, coupling agents, antistatic agents, dispersant, weather resistant agents, pigments, dyes, and inorganic fillers.

[13] A molded article prepared by extruding the flameproof thermoplastic resin composition of any one of Claims 1~12, wherein the molded article has a specific gravity of about 1.1 to about 1.5 measured in accordance with ASTM

D792 and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12".

[14] A molded article prepared by extruding the flameproof thermoplastic resin composition of Claim 10, wherein the molded article has an Izod impact strength of about 6.8 to 15 kgf-cm/cm measured in accordance with ASTM-D256 at a thickness of 1/8", a specific gravity of about 1.1 to about 1.5 measured in accordance with ASTM D792, and flame retardancy of V-O measured in accordance with UL-94 at a thickness of 1/12".

[15] A method for preparing a flameproof thermoplastic resin composition, the method comprising extruding a thermoplastic resin composition at 120~280 ⁰C, wherein said thermoplastic composition comprises 100 parts by weight of a thermoplastic resin, about l~40 parts by weight of a sublimational filler, and about l~30 parts by weight of a flame retardant.

[16] A method for improving flame retardancy by adding a sublimational filler which has a sublimation temperature of about 200~500 ⁰C to a flameproof resin comprising a thermoplastic resin and a flame retardant.