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US 5,859,833 AGranted
Optical disk grade copolyestercarbonates derived from hydroxyphenylindanols
AssigneeGeneral Electric Company
InventorsGautam Chatterjee, Gary Charles Davis
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Abstract
Copolycarbonates having low intrinsic birefringence comprise structural units derived from hydroxyphenylindanol, from resorcinol, alkylenedioic acid or eugenolsiloxane, and, optionally, from a bisphenol, preferably bisphenol A. The copolycarbonates are useful for the fabrication of optical data recording media such as compact disks.
Claims13
A copolyestercarbonate having low birefringence, said copolyestercarbonate comprising:
- (A) about 20-90 mole percent of structural units of the formula ##STR5## (B) about 3-70 mole percent of structural units of the formula ##STR6## wherein R.sup.1 is alkyleneoxy, m-phenyleneoxy, ##STR7## R.sup.2 is C.sub.2-6 alkylene or O, R.sup.3 is C.sub.1-4 primary or secondary alkyl or fluoroalkyl or phenyl, R.sup.5 is C.sub.1-4 alkyl or alkoxy, m is 0-2, n is in the range of about 4-25 and p has an average value from 1 to 100;
- and, optionally,
- (C) structural units of the formula ##STR8## wherein each of A.sup.1 and A.sup.2 is independently unsubstituted or substituted m- or p-phenylene and Y is a single bond or a linking group wherein 1 or 2 atoms separate A.sup.1 from A.sup.2.
Dependencies are inferred from the claim text.