Patent ID: 6060576
Filing Date: 2000-05-09
Classification: C08G

Abstract:
A method for preparing a polycarbonate precursor mixture of enhanced crystallinity which comprises melt blending, under non-reactive conditions, an amorphous precursor polycarbonate consisting essentially of structural units of the formula ##STR4## wherein each of A.sup.1 and A.sup.2 is independently a divalent aromatic radical and Y is a bridging radical wherein one or two atoms separate A.sup.1 from A.sup.2, with one or more dihydroxyorganic monomers selected from the group consisting of a spiro(bis)indane bisphenol of the formula, ##STR5## a phenylindane bisphenol of the formula ##STR6## a mixture of (II) or (III) with another dihydroxy organic monomer and a mixture of (II) and (III) with another dihydroxy organic monomerwherein R.sup.1 is hydrogen or C.sub.1-4 primary or secondary alkyl and n is 0-2,to form a monomer-polymer mixture; pelletizing said mixture; and treating the pelletized mixture to enhance the crystallinity of the polymer therein.