Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-11-16
2002-04-09
Hoke, Veronica P. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C524S164000
Reexamination Certificate
active
06369141
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 has an excellent weather-resistance.
BACKGROUND OF THE INVENTION
Polycarbonate resin compositions have excellent mechanical properties, so that they have been used as engineering plastics in various fields such as automobiles, office automation instruments, and electric/electronic products, in particular for products which require flammability, such as office automation instruments and home electric appliances. Conventionally, halogenated compounds have been mainly used for flame-retardant polycarbonate resins. Recently many resin compositions which contain halogen-free materials such as phosphorus-containing flame retardants (e.g., phosphate esters) have been reported in order to overcome problems such as environmental pollution. However, these resin compositions may have problems that the impact resistance and the heat stability are low.
Also reported are use of condensed phosphate esters having a structure which is derived from resorcinol in order to overcome a problem of mold deposit when molded.
Japanese Patent Laid-Open Publication No. 6-228426 and Japanese Patent Laid-Open Publication No. 7-53876 disclose resin compositions obtained by mixing condensed phosphate esters having a structure which is derived from Bisphenol A with thermoplastic resins such as polycarbonate resins, in which the bleeding property or hydrolysis resistance is improved. However, these conventional polycarbonate resin compositions have imbalanced combination of flammability, impact resistance and heat stability, and have no good weather-resistance and no good appearance after they stayed under a severe molding conditions or a molding machine.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a flame-retardant polycarbonate resin composition which has an excellent mechanical properties, an excellent heat stability, an excellent flammability, as well as an excellent mold-depositing property, more preferably, which has an excellent weather-resistance and an excellent appearance when it stayed under a severe molding condition or in a molding machine.
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 mixing a specific amount of each of a phosphorus-containing flame retardant, polyfluoroethylene and a multi-layered polymer with an aromatic polycarbonate resin. The present invention has been 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) 0.5-40 parts by weight of a phosphorus-containing flame retardant, (c) 0.01-5 parts by weight of polyfluoroethylene, (d) 0-5 parts by weight of sulfonic acid metal salt, and (e) 0.5-30 parts by weight of a multi-layered polymer having a core layer made of an elastic polymer having a glass-transition temperature (Tg) lower than a room temperature, and an outer layer made of a thermoplastic resin having an adhesiveness or miscibility to polycarbonate, provided that the composition comprises 3-40 parts by weight of a phosphorus-containing flame retardant when said composition comprises substantially no sulfonic acid metal salt.
Preferably, the composition according to the present invention comprises 3-40 parts by weight of a phosphorus-containing flame retardant (b), and comprises substantially no sulfonic acid metal salt (d).
Preferably, the composition according to the present invention further comprises (f) 2 parts by weight or less of a UV-light absorber.
Preferably, the composition according to the present invention further comprises (g) 0.1-20 parts by weight or less of a surface-treated titanium oxide.
Preferably, the aromatic polycarbonate resin (a) is derived from 2,2-bis(4-hydroxyphenyl)propane.
Preferably, the aromatic polycarbonate resin (a) has a viscosity-average molecular weight of 16,000-30,000.
Preferably, the phosphorus-containing flame retardant (b) is represented by formula I or II below:
wherein Ra, Rb, and Rc are each independently a C1-C6 alkyl group or a C6-C20 aryl group optionally substituted with a C1-C6 alkyl group; h, i and j are each independently 0 or 1;
wherein Rd, Re, Rf, and Rg are each independently a C1-C6 alkyl group or a C6-C20 aryl group optionally substituted with a C1-C6 alkyl group; p, q, r and s are each independently 0 or 1; m is an integer of 1-5; and X is an arylene group.
Preferably, the phosphorus-containing flame retardant (b) is represented by formula III below:
wherein R
1
and R
2
are each independently methyl group, hydrogen atom or phenyl group; n is an integer from 1 to 5.
Preferably, polyfluoroethylene (c) has a fibril-forming ability.
Preferably, the multi-layered polymer (e) contains alkyl(meth)acrylate polymer.
Preferably, the multi-layered polymer (e) has an outer layer consisting of alkyl (meth)acrylate polymer.
Preferably, the multi-layered polymer (e) has a core layer made of an elastic polymer consisting of alkyl(meth)acrylate polymer.
Preferably, the multi-layered polymer (e) has a core layer made of an elastic polymer consisting of crosslinked alkyl(meth)acrylate polymer having a glass-transition temperature of 0° C. or lower, and an outer layer made of alkyl (meth)acrylate polymer.
Preferably, the multi-layered polymer (e) has a core layer made of a diene-containing polymer.
Preferably, the multi-layered polymer (e) has a core layer made of a polybutadiene or a butadiene/styrene copolymer.
Preferably, the multi-layered polymer (e) has a core layer made of a crosslinked butadiene-containing copolymer.
According to another aspect of the present invention, there is provided a molded product made of a flame-retardant polycarbonate resin composition which comprises (a) 100 parts by weight of an aromatic polycarbonate resin, (b) 0.5-40 parts by weight of a phosphorus-containing flame retardant, (c) 0.01-5 parts by weight of polyfluoroethylene, (d) 0-5 parts by weight of sulfonic acid metal salt, and (e) 0.5-30 parts by weight of a multi-layered polymer having a core layer made of an elastic polymer having a glass-transition temperature (Tg) lower than a room temperature, and an outer layer made of a thermoplastic resin having an adhesiveness or miscibility to polycarbonate, provided that the composition comprises 3-40 parts by weight of a phosphorus-containing flame retardant when said composition comprises substantially no sulfonic acid metal salt.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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 according to the present invention comprises (a)100 parts by weight of an aromatic polycarbonate resin, (b)0.5-40 parts by weight of a phosphorus-containing flame retardant, (c)0.01-5 parts by weight of polyfluoroethylene, (d)0-5 parts by weight of sulfonic acid metal salt, and (e)0.5-30 parts by weight of a multi-layered polymer having a core layer made of an elastic polymer having a glass-transition temperature (Tg) lower than a room temperature, and an outer layer made of a thermoplastic resin having an adhesiveness or miscibility to polycarbonate, provided that said composition comprises (d)0.01-5 parts by weight of sulfonic acid metal salt when said composition comprises (b) 0.5-3 parts by weight of a phosphorus-containing flame retardant.
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
Ishii Kazuhiko
Nakata Michio
Shimomai Ken
Hoke Veronica P.
Mitsubishi Engineering-Plastics Corporation
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