Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-11-15
2002-01-29
Yoon, Tae H. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S166000, C524S463000, C524S504000
Reexamination Certificate
active
06342550
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a flame-retardant polycarbonate resin composition, more particularly to a flame-retardant polycarbonate resin composition which contains only a small amount or none of a phosphorus-containing flame-retardant, but has an excellent flame resistance.
BACKGROUND OF THE INVENTION
Polycarbonate resins are widely used in automobile industry, office automation instrument industry, electric/electronic industry and the like. Flame-retardant resin materials are eagerly required for office automation instruments, home electric appliances, and other products. In order to answer the requirement, many kinds of flame-retardants are being developed. For flame-retardants for polycarbonate resins, brominated compounds are usually used singly or together with antimony trioxide. These resin compositions have, however, such a problem that they can cause an environmental pollution because of generation of bromine-containing gases when burnt.
Recently in order to reduce the amount of using those brominated compounds considering the above-mentioned problem, polycarbonate resin compositions containing, for example, phosphorus-containing flame-retardants such as phosphate esters have been reported. These compositions, however, have such faults that impact and heat resistances are low. In addition, the above-mentioned environmental pollution problem is not solved completely by those compositions. Phosphorus-free flame-retardant materials include a flame-retardant polycarbonate resin composition prepared by adding an organic alkaline metal salt or an organic alkaline earth metal salt and polytetrafluoroethylene to an aromatic polycarbonate (see Japanese Patent Laid-Open Publication No. 51-45159). It was difficult, however, to obtain a resin material which has excellent heat and impact resistances, and satisfies a severe UL flame resistance level of V-0 in a molded product, having a thickness of 1 mm or thinner, which is required for thin wall molding.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a flame-retardant polycarbonate resin composition containing a small amount or none of a phosphorus-containing flame-retardant, which is safe to the environment, whose properties are not deteriorated by decomposition of a phosphorus-containing flame-retardant when use, and which has excellent impact and heat resistances as well as an excellent moldability, and can satisfy the flame resistance level as high as a conventional composition containing a phosphorus-containing flame-retardant.
The present inventors carried out zealous research in order to achieve the above-mentioned object, and found that an excellent flame-retardant polycarbonate resin composition having desired properties can be obtained by admixing a specific amount of each of an organic sulfonic acid metal salt, a fluorinated polyolefin and a diene-containing multi-layered polymer, to an aromatic polycarbonate resin. The present invention was completed on the basis of these findings.
According to the present invention, there is provided a flame-retardant polycarbonate resin composition which comprises (A) 100 parts by weight of an aromatic polycarbonate resin, (B) 0.01-5 parts by weight of an organic sulfonic acid metal salt, (C) 0.01-5 parts by weight of a fluorinated polyolefin, (D) 0.2-20 parts by weight of a diene-containing multi-layered polymer, and wherein the content of a phosphorus-containing flame-retardant is less than 0.5 parts by weight.
Preferably, the aromatic polycarbonate resin (A) is a polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane. Preferably, the aromatic polycarbonate resin (A) has a viscosity-average molecular weight of 15,000-30,000.
Preferably, the organic sulfonic acid metal salt (B) is a perfluoroalkane-sulfonic acid metal salt. Preferably, the metal of said organic sulfonic acid metal salt (B) is an alkaline metal or an alkaline earth metal.
Preferably, the fluorinated polyolefin (C) is polytetrafluoroethylene, and more preferably polytetrafluoroethylene having an ability of forming fibril.
Preferably, the diene-containing multi-layered polymer (D) has an inner layer consisting mainly of a diene-containing elastic polymer, and an outer layer consisting mainly of a polymer other than a diene-containing elastic polymer. Preferably, the outer layer of the multi-layered polymer consists mainly of a thermoplastic resin which improves adhesiveness or miscibility with an aromatic polycarbonate resin. More preferably, the polymer of the outer layer of a multi-layered polymer is a polymer obtained by polymerizing one or more monomers selected from a group consisting of aromatic vinyl monomers, vinyl cyanide monomers, methacrylate ester monomers, and acrylate ester monomers. Particularly preferably, the diene-containing multi-layered polymer (D) has an inner layer consisting mainly of an elastic polymer obtained by polymerizing monomers containing butadiene, and an outer layer consisting mainly of a polymer obtained by polymerizing monomers containing methyl methacrylate.
In a particularly preferred embodiment of the present invention, the aromatic polycarbonate resin (A) is a polycarbonate resin derived from 2,2-bis(4-hydroxyphenyl)propane, the organic sulfonic acid metal salt (B) is an alkaline metal salt or an alkaline earth metal salt of a perfluoroalkane-sulfonic acid, the fluorinated polyolefin (C) is a polytetrafluoroethylene, and the diene-containing multi-layered polymer (D) has a core layer consisting mainly of an elastic polymer obtained by polymerizing monomers containing butadiene, and an outer layer consisting mainly of a polymer obtained by polymerizing monomers containing methyl methacrylate.
In the present invention, the content of a phosphorus-containing flame-retardant is preferably 0.3 parts by weight or less, and more preferably 0.1 parts by weight or less per 100 parts by weight of an aromatic polycarbonate resin. Particularly preferably, the composition contains substantially no phosphorus-containing flame-retardant.
According to another aspect of the present invention, there is provided a molded product which is made of a flame-retardant polycarbonate resin composition which comprises (A) 100 parts by weight of an aromatic polycarbonate resin, (B) 0.01-5 parts by weight of an organic sulfonic acid metal salt, (C) 0.01-5 parts by weight of a fluorinated polyolefin, (D) 0.2-20 parts by weight of a diene-containing multi-layered polymer, and wherein the content of a phosphorus-containing flame-retardant is less than 0.5 parts by weight.
Preferably, the molded product of the present invention has an Izod impact strength of 392 J/m (40 kgf-cm/cm) or larger.
Preferably, the molded product of the present invention has a deflection temperature under load of 129° C. or higher.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below. The values on both ends of symbol “-” in this specification mean a range from a lower limit to an upper limit, wherein the range includes both values.
The flame-retardant polycarbonate resin composition of the present invention comprises (A) 100 parts by weight of an aromatic polycarbonate resin, (B) 0.01-5 parts by weight of an organic sulfonic acid metal salt, (C) 0.01-5 parts by weight of a fluorinated polyolefin, (D) 0.2-20 parts by weight of a diene-containing multi-layered polymer, and the content of a phosphorus-containing flame-retardant is less than 0.5 parts by weight.
The aromatic polycarbonate resin used for the present invention includes a homopolymer or copolymer of an optionally blanched thermoplastic aromatic polycarbonate which is prepared by reacting an aromatic hydroxyl compound or a mixture of an aromatic hydroxyl compound and a small amount of polyhydroxyl compound with a phosgene or carbonate diester. The polymerization for preparing the aromatic polycarbonate resin includes “interfacial polycondensation (phosgenation method)” and “fusion cook method (ester exchange process)”.
The aromatic hydroxyl compound used for the present
Ishii Kazuhiko
Shimomai Ken
Mitsubishi Engineering Plastics Corporation
Sughrue Mion Zinn Macpeak & Seas, PLLC
Yoon Tae H.
LandOfFree
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