Patent ID: 7524919

Claim:
A copolycarbonate comprising 90 to 100 mol % of units derived from a cycloalkylidene-bridged alkyl-substituted bisphenol of the formula wherein R a′ and R b′ are each independently C 1-12 alkyl, T is a C 5-16 cycloalkylene, or a C 5-16 cylcloalkylidene, and r and s are each independently 1 to 4; 2 to 35 wt % of units derived from a polysiloxane diol of the formulas or a combination thereof, wherein Ar is a substituted or unsubstituted C 6-36 arylene group, each R is the same or different C 1-13 monovalent organic group, each R 6 is the same or different divalent C 1 -C 30 organic group, and E is an integer from 40 to 60; and 0 to 10 mol % of units derived from a dihydroxy aromatic compound of formula wherein R a and R b are each independently halogen or C 1-12 alkyl group, X a is a C 1-18 organic group, p and q are each independently integers of 0 to 4, and the dihydroxy aromatic compound is not the same as the cycloalkylidene-bridged bisphenol or the polysiloxane diols; and wherein each of the foregoing mole percents is based on the total moles of bisphenol of formula (1) and dihydroxy aromatic compound of formula (3) used to manufacture the copolycarbonate, and the weight percent is based on the total weight of the bisphenol of formula (1), polysiloxane diols of formula (2a) and/or (2b), and dihydroxy aromatic compound of formula (3) used to manufacture the copolycarbonate.