Patent ID: 7834125

Claim:
A melt polymerized polycarbonate comprising repeat units derived from the melt polymerization of monomers (II), (IV), and optionally (VIII), or from the melt polymerization of monomers (III), (IV), and optionally (VIII), or from the melt polymerization of monomers (II), (III), (IV), and optionally (VIII), wherein monomer (II) is a first dihydroxy compound of structure (II): wherein n is 0 to 4, and each R f1 is independently a halogen, a C 1-12 hydrocarbyl group, or a C 1-12 halogen substituted hydrocarbyl group; monomer (III) is a second dihydroxy compound not the same as monomer (II) and of structure (III): wherein m is 1 to 4, and R f2 is independently a halogen, a C 1-12 hydrocarbyl group, or a C 1-12 halogen substituted hydrocarbyl group; monomer (IV) is a third dihydroxy compound of structure (IV): wherein R a and R b are each independently a halogen or C 1-12 hydrocarbyl group that is meta to the hydroxy group on the same aromatic ring; R c and R d are each independently a halogen or a C 1 -C 12 hydrocarbyl group that is ortho to the hydroxy group on the same aromatic ring; p and q are each independently 0 to 2; v and w are each independently 1 or 2; and X a is a single bond or a C 1-18 organic bridging group connecting the two hydroxy-substituted aromatic groups; and monomer (VIII) is a fourth dihydroxy compound of structure (VIII): wherein R a and R b are each independently a halogen or C 1-12 hydrocarbyl group that is meta to the hydroxy group on the same aromatic ring; p and q are each independently integers of 0 to 2; and X a is a single bond or a C 1-18 organic group connecting the two hydroxy-substituted aromatic group; wherein the mole ratio of repeat units in the polycarbonate derived from monomers [(II)+(III)]:(IV):(VIII) is 15-70:1-85:0-50, the sum of the mole percent of repeat units in the polycarbonate derived from monomers [(II)+(III)]+(IV) is greater than or equal to 50 mole %, and the sum of the mole percent of units in the polycarbonate derived from monomers [(II)+(III)]+(IV)+(VIII) is 100 mole %; and wherein the polycarbonate has an L* value that is at least 1 L* unit value higher than the same polycarbonate in which monomer (IV) is replaced by bisphenol A.