Patent ID: 7504472
Filing Date: 2009-03-17
Classification: C08K,Y10T

Abstract:
1. A polycarbonate nanocomposite composition, comprising: at least one crystallized polycarbonate; and exfoliated sepiolite clay or exfoliated attapulgite clay, prepared by a process comprising the steps: (a) preparing a nanocomposite of polycarbonate and sepiolite clay or attapulgite clay, by polymerizing at least one polycarbonate precursor in the presence of sepiolite clay or attapulgite clay and a catalyst to form a polycarbonate; (b) heating the nanocomposite to a temperature above the glass transition temperature of the polycarbonate produced in step (a) at which the polycarbonate is formable; (c) optionally, melt-mixing the nanocomposite with one or more additional ingredients; (d) forming the product of step (b) or (c) into particles; (e) cooling the particles to a temperature below a melting point of said polycarbonate and above the glass transition temperature of said polycarbonate; and (f) allowing the particles to crystallize at the temperature to which they were cooled in step (e).