Thermoplastic molding compositions and process
AssigneeGeneral Electric Company
InventorsStuart C. Cohen, Robert J. Kostelnik, Allen D. Wambach
Life of this patent
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Abstract
Flame-retardant thermoplastic molding compositions having improved physical and electrical arc track resistant properties are provided, the compositions comprising an intimate admixture of (a) a high molecular weight poly(1,4-butylene terephthalate) homo- or co-polyester, (b)(i) a copolymer of ethylene and vinyl acetate in combination with an aromatic polycarbonate; (ii) poly(ethylene terephthalate); or (iii) reinforcing glass; (c) a flame retardant agent; and (d) a mineral filler.
Claims17
A flame retardant thermoplastic molding composition having improved physical properties, the composition consisting essentially of an intimate mixture of:
- (a) a high molecular weight poly(1,4-butylene terephthalate) homo- or copolyester resin;
- (b) (i) a copolymer comprised of ethylene and vinyl acetate in combination with an aromatic polycarbonate derived from bisphenol A;
- or (ii) a mixture of a reinforcing amount of glass fibers and a copolymer comprised of ethylene and vinyl acetate in combination with an aromatic polycarbonate derived from bisphenol-A;
- (c) a flame retardant amount of a flame retardant additive;
- and
- (d) a mineral filler selected from the group consisting of silica, mica, talc, pysophillite, wollastonite and mineral wool, and mixtures of any of the foregoing;
- component (d) being present in an amount of from about 5 to about 40% by weight sufficient to provide electrical arc track resistance superior to that of a corresponding composition in which mineral filler component (d) is not present.
In a process for the preparation of a flame retardant molding composition having improved physical properties comprising forming an intimate melt-blended admixture consisting essentially of:
- (a) a high molecular weight poly(1,4-butylene terephthalate) homo- or copolyester resin;
- (b) (i) a copolymer comprised of ethylene and vinyl acetate in combination with an aromatic polycarbonate derived from bisphenol-A;
- or (ii) a reinforcing amount of glass fibers and a copolymer comprised of ethylene and vinyl acetate in combination with an aromatic polycarbonate derived from bisohenol-A and
- (c) a flame retardant amount of a flame retardant additive;
- the improvement comprising the step of including in said intimate admixture
- (d) a mineral filler selected from the group consisting of silica, mica, talc, pyrophillite, wollastonite and mineral wool, and mixtures of any of the foregoing in an amount of from about 5 to 40% by weight at least sufficient to provide the composition with electrical arc track resistance superior to that of a corresponding composition in which mineral filler component (d) is not present.
A flame retardant thermoplastic molding composition having improved physical properties, the composition consisting of an intimate admixture of:
- (a) a high molecular weight poly(1,4-butylene terephthalate) homo- or copolyester resin;
- (b) (i) a copolymer comprised of ethylene and vinyl acetate in combination with an aromatic homopolycarbonate;
- (ii) a high molecular weight polyethylene terephthalate resin;
- (iii) a mixture of a reinforcing amount of glass fibers and a copolymer comprised of with an aromatic homopolycarbonate;
- (iv) a mixture of a reinforcing amount of glass fibers and a high molecular weight polyethylene terephthalate resin, or (v) a mixture of (i), (ii) and a reinforcing amount of glass fibers;
- (c) a flame retardant amount of a flame retardant additive;
- and
- (d) a mineral filler selected from the group consisting of silica, mica, talc, pyrophillite, wollastonite and mineral wool, and mixtures of the foregoing;
- component (d) being present in an amount of from about 5 to about 40% by weight sufficient to provide electrical arc track resistance superior to that of a corresponding composition in which mineral filler component (d) is not present.
A flame retardant thermoplastic molding composition having improved physical properties, the composition consisting of an intimate admixture of:
- (a) a high molecular weight poly(1,4-butylene terephthalate) homo or copolyester resin;
- (b) (i) a copolymer consisting of ethylene and vinyl acetate in combination with an aromatic homopolycarbonate;
- (ii) a high molecular weight polyethylene terephthalate resin;
- (iii) a mixture of a reinforcing amount of glass fibers and component (b) (i);
- (iv) a mixture of a reinforcing amount of amount of glass fibers and component (b) (ii);
- or (v) a mixture of a reinforcing amount of glass fibers, component (b) (i) and component (b) (ii);
- (c) a flame retardant amount of a flame retardant additive;
- and
- (d) a mineral filler selected from the group consisting of silica, mica, talc, pyrophillite, wollastonite and mineral wool, and mixtures of the foregoing;
- component (d) being present in an amount of from about 10 to about 30% by weight sufficient to provide electrical arc track resistance superior to that of a corresponding composition in which mineral filler component (d) is not present.
Dependencies are inferred from the claim text.