Method for producing purified polycarbonate resin with fluid containing CO.sub.2
AssigneeMitsubishi Gas Chemical Company, Inc.
InventorsShigeo Kondoh, Toshikazu Umemura
Life of this patent
Estimating the term…
Abstract
A method for producing a purified polycarbonate resin is disclosed, comprising contacting a solid polycarbonate resin with a fluid comprising at least 70% by weight of carbon dioxide and having a temperature of 30.degree. to 120.degree. C. and a pressure of at least 10 kg/cm.sup.2. The method can effectively remove almost all the impurities contained in the polycarbonate resin within a very short period of time, thereby providing highly purified polycarbonate resin materials which are suitably used in the fields of information, electronic and medical industries.
Claims4
A method for producing a purified polycarbonate resin, which comprises contacting a solid polycarbonate resin selected from the group consisting of a polycarbonate resin, a resin composition comprising the polycarbonate resin in combination with a polyester resin selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, cyclohexanedimethanol/terephthalic acid/isophthalic acid copolymer or cyclohexanedimethanol/ethylene glycol/terephthalic acid copolymer, a polystyrene, a styrene/maleic anhydride copolymer, a styrene/maleimide copolymer, a styrene/maleic anhydride/maleimide copolymer or a styrene/(meth)acrylic acid ester copolymer, and a polycarbonate copolymer selected from the group consisting of graft copolymers comprising the polycarbonate and a polystyrene, a styrene/maleic anhydride copolymer, a styrene/maleimide copolymer, a styrene/maleic anhydride/maleimide copolymer and a styrene/(meth)acrylic acid ester copolymer, with a fluid comprising at least 70% by weight of carbon dioxide and having a temperature of 30.degree. to 120.degree. C. and a pressure of at least 10 kg/cm.sup.2.
Dependencies are inferred from the claim text.