Color improved polycarbonate compositions and molded articles
AssigneeGeneral Electric Company
InventorsJames L. DeRudder, Richard W. Howery
Life of this patent
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Abstract
A thermoplastic molding composition including at least one polycarbonate resin which is a polycarbonate homopolymer or copolymer; and an amount of at least one tetrahalobisphenol A copolymer effective to reduce the yellowness index of the at least one polycarbonate resin as determined after thermally molding the composition into an article. The article molded from the thermoplastic molding composition has a lower yellowness index than that of an article molded from a corresponding thermoplastic molding composition which does not contain any of the at least one tetrahalobisphenol A copolymer.
Claims8
A method of preparing a thermally molded article having improved color, comprising:
- a. formulating a thermoplastic molding composition which is a blend and which comprises:
- at least one polycarbonate resin which is a polycarbonate homopolymer or copolymer;
- and
- less than about 0.4% by weight of at least one polycarbonate copolymer of tetrahalo bisphenol A and bisphenol A, having a halogen content of about 27% by weight, effective to reduce yellowness index of the at least one polycarbonate resin;
- and
- b. thermally molding an article from the thermoplastic molding composition,
- wherein the article has a lower yellowness index than that of an article molded from a corresponding thermoplastic molding composition which does not contain any of the at least one copolymer.
The process of improving color of a polycarbonate composition and articles molded therefrom, comprising:
- including in a polycarbonate composition comprised of at least one polycarbonate resin which is a polycarbonate homopolymer or copolymer, less than about 0.4% by weight of at least one polycarbonate copolymer of tetrahalobisphenol A and bisphenol A, having a halogen content of about 27% by weight, effective to reduce yellowness index of the at least one polycarbonate resin, as measured after thermally molding an article from the poly-carbonate composition.
Dependencies are inferred from the claim text.