Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-10-13
2003-03-11
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S145000
Reexamination Certificate
active
06531534
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a thermoplastic resin composition that is useful as a material for parts of OA equipment, communication equipment, housing for electric appliances, chassis and the like, and materials for parts of automobiles.
PRIOR ART
Hitherto, a polymer blend of a polycarbonate resin and a styrene resin has been widely used in automobiles, OA equipment, electronic and electric fields, and the like. However, the polycarbonate resin is poor in resistance against hydrolysis. Thus, in the case that various products composed of the above-mentioned polymer blend are used or allowed to stand under a high temperature and high humidity for a long time, there arises a problem that their strength drops.
Since flame resistance is required for OA equipment, electric appliances and the like, various kinds of flame retardants are blended in the base resin thereof. Conventionally, a halogen flame retardant such as bromine or chlorine is widely used as the flame retardant. However, there remains a problem that a corrosive gas is generated at the time of processing or burning. Therefore, research and development on organic phosphorus compounds are being made as a flame retardant in place of the halogen flame retardant. However, the organic phosphorus compounds also function as plasticizers so as to make the thermal deformation temperature very low. Thus, there arises a problem that uses of the resin composition are restricted.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a thermoplastic resin composition which makes it possible to improve the resistance against hydrolysis of a molded article obtained from a composition comprising, as a base resin, a polymer blend of a polycarbonate resin and a styrene resin, and decrease the amount of an organic phosphorus compound blended without any drop in flame resistance.
The present invention is a thermoplastic resin composition comprising 100 parts by weight of (a) a polycarbonate resin, 1 to 40 parts by weight of (c) an organic phosphorus compound and 0.1 to 5 parts by weight of (e) talc. Preferably, a mixture of 30 to 95% by weight of (a) a polycarbonate resin and 5 to 70% by weight of (b) a styrene resin may be used in place of the above-mentioned component (a).
The composition of the invention preferably comprises 100 parts by weight of a mixture of 30 to 95% by weight of (a) a polycarbonate resin and 5 to 70% by weight of (b) a styrene resin, 1 to 40 parts by weight of (c) an organic phosphorus compound and 0.1 to 5 parts by weight of (e) talc, and further comprises 0.05 to 5 parts by weight of a polymer of (d) a fluoroethylene.
Further, it optionally comprises 0.1 to 20 parts by weight of (f) an anti-impact improver.
It is preferable that (f) the anti-impact improver is at least one copolymer selected from the group consisting of (f-1) to (f-4) below defined:
(f-1) a copolymer of an aromatic vinyl compound and a conjugated diene compound or a hydrogenated product of the copolymer;
(f-2) an epoxydized product of a copolymer of an aromatic vinyl compound and a conjugated diene compound or a hydrogenated product of the epoxydized product;
(f-3) a copolymer of an aromatic vinyl compound and a monomer polymerizable with the aromatic vinyl compound; and
(f-4) a graft copolymer obtained by graft-polymerizing an aromatic vinyl compound and a monomer polymerizable with the aromatic vinyl compound on the body of a rubbery polymer having a glass transition point of −30° C. or lower.
In a preferred embodiment of the present invention, the anti-impact improver (f) comprises (f-3) and (f-4), the monomer polymerizable with the aromatic vinyl compound is a (meth)acrylic ester monomer; and (f-3) is a graft copolymer. Specifically, (f-3) is a graft copolymer of an aromatic vinyl compound and a (meth)acrylic ester monomer and contains 50% by weight or less of the (meth)acrylic ester monomer in terms of starting monomers. More specifically, (f-3) is a copolymer of methyl methacrylate and styrene and (f-4) is a graft copolymer of methyl methacrylate, styrene and butadiene.
Further, the composition of the present invention optionally comprises 0.1 to 20 parts by weight of (g) polyphenylene ether resin.
The present invention is a molded article of the above-mentioned composition, which has an excellent resistance to hydrolysis. The number-average molecular weight of the component (a) is reduced by 0 to 20% when the molded article has been allowed to stand in an atmosphere of 40° C. and 90%RH for 1000 hr.
The thermoplastic resin compositions of the present invention can be classified into a three-component type composition comprising (a) a polycarbonate resin, (c) an organic phosphorus compound and (e) talc, and a five-component type composition comprising (a) a polycarbonate resin, (b) a styrene resin, (c) an organic phosphorus compound, (d) a fluoroethylene polymer and (e) talc. Since the components contained in these compositions overlap with each other, the following will describe the five-component type composition comprising a larger number of the components, thereby describing the three-component type composition.
DETAILED DESCRIPTION OF THE INVENTION
The polycarbonate resin of the component (a) used in the present invention can be obtained by reacting a bivalent phenol with a carbonate precursor in the known solution or melting method.
The bivalent phenol may be one or more selected from 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)sulfone and the like. Among these, bis(4-hydroxyphenyl)alkanes are preferable. Bisphenol A is especially preferable.
The carbonate precursor may be one or more selected from a diarylcarbonate such as diphenylcarbonate; dialkylcarbonate such as dimethylcarbonate and diethylcarbonate; carbonyl halide such as phosgene; haloformate such as a dihaloformate of a bivalent phenol; and the like.
The number-average molecular weight of the polycarbonate resin (a) is not especially limited. In order to give practically-required mechanical strength to the molded article obtained from the composition, it is preferably in the range of from about 17000 to 32000.
The styrene resin (b) used in the present invention may be any one of (b-1) a rubber-unmodified styrene resin containing no rubber, and (b-2) a rubber-modified styrene resin.
The component (b-1) may be a homopolymer or a copolymer of one or more selected from aromatic vinyl monomers; or a copolymer of an aromatic vinyl monomer and a non-styrene vinyl monomer which can be copolymerized with it.
Examples of the aromatic vinyl monomer include styrene monomers such as styrene, alkyl-substituted styrene (for example, o-methylstyrene, p-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene and p-tert-butylstyrene), and -alkyl-substituted styrene (for example, -methylstyrene and -methyl-p-methylstyrene). Among these, styrene, p-methylstyrene and -methylstyrene are preferable, and styrene and -methylstyrene are particularly preferable.
Examples of the non-styrene vinyl monomer which can be copolymerized with the aromatic vinyl monomer include cyanovinyl monomers (for example, acrylonitrile and methacrylonitrile), (meth)acryl monomers (for example, an alkyl(meth)acrylate having 1 to 10 carbon atoms, such as methyl methacrylate, ethyl acrylate and butyl acrylate; (meth)acrylic esters having a functional group, such as 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate), maleic anhydride, and N-substituted maleimide. Among these, acrylonitrile, methacrylonitrile, (meth)acrylic esters having 1 to 4 carbon atoms, maleic anhydride, and N-substituted maleimide are preferable. Acrylonitrile and methyl methacrylate are especially preferable.
Examples of the blend ratio of the respective monomers in the case that the component (b-1) is a copolymer are as follows. The aromatic vinyl mo
Cain Edward J.
Daicel Chemical Industries Ltd.
Flynn ,Thiel, Boutell & Tanis, P.C.
LandOfFree
Thermoplastic resin composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermoplastic resin composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoplastic resin composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3069939