Patent ID: 8916259

Claim:
A multilayer thermoplastic film comprising: a first layer comprising a first polycarbonate polymer that comprises repeat units derived from monomers (II), (III), and (IV), wherein monomer (II) is a first dihydroxy compound of the formula: wherein n is 0 to 4, and R f1 is a halogen, a C 1-10 hydrocarbon group, or a C 1-10 halogen-substituted hydrocarbon group; monomer (III) is a second dihydroxy compound not the same as monomer (II) and of the formula: wherein m is 1 to 4, and R f2 is a halogen, a C 1-10 hydrocarbon group, or a C 1-10 halogen-substituted hydrocarbon group; and monomer (IV) is a third dihydroxy compound of the formula: wherein R a and R b are each independently a halogen or C 1-12 alkyl group that is meta to the hydroxy group on the same aromatic ring; R c and R d each independently represent a C 1 -C 12 alkyl group that is ortho to the hydroxy group on the same ring; p and q are each independently integers of 0 to 2; v and w are each independently integers 0 to 2; and X a is a single bond or a bridging group; wherein the sum of the mole percent of the repeat units derived from monomers (II) and (III) is greater than or equal to 30 mole percent, based on the total moles of the repeat units derived from monomers (II), (III), and (IV) in the first polycarbonate polymer, the mole percent of the repeat units derived from monomer (IV) is 5 to 70 mole percent, based on the total moles the repeat units derived from monomers (II), (III), and (IV), and the total wt. % of the repeat units derived from monomers (II), (III), and (IV) is greater than or equal to 80 wt. % of the first polycarbonate polymer; an additional polycarbonate polymer that is not the same as the first polycarbonate polymer, wherein the additional polycarbonate polymer comprises 50 to 100 mole percent of repeat units derived from a bisphenol cyclohexane of the formula (VI): wherein R c1 and R d1 are each independently C 1-12 alkyl, R c2 and R d2 are each independently hydrogen or C 1-12 alkyl, R g is C 1-12 alkyl or halogen, and t is 0 to 10; and 0 to 50 mole percent of repeat units derived from a dihydroxy aromatic compound of formula (VIII): wherein R e and R f are each independently a halogen or C 1-10 alkyl group; r and s are each independently integers of 0 to 4; X a is a single bond or a bridging group connecting the two hydroxy-substituted aromatic groups; and the dihydroxy aromatic compound of formula (VIII) is not the same as the bisphenol cyclohexylidene of formula (VI); and 0.002 wt. % to 0.07 wt. % of a catalyst for the reaction of the first polycarbonate polymer and the additional polycarbonate polymer, based on the total weight of the polycarbonate polymers; and a second layer in contact with the first layer, wherein the second layer comprises a second polycarbonate polymer that is not the same as the first polycarbonate polymer in the first layer.