Patent ID: 7682672

Claim:
A negative C-type compensation film comprising: a) a base layer; and b) a polymer layer comprising polyarylate which comprises a repeating unit represented by the formula (1) and prepared by copolymerizing divalent phenols, divalent aromatic carboxylic acid halides, and 0.01 to 49.9 mol % of bisphenol derivatives of the formula (2), the base layer and the polymer layer being sequentially layered, wherein R 1 to R 8 are each independently hydrogen, alkyl having 1 to 12 carbon atoms, arylalkyl having 7 to 12 carbon atoms, aryl having 6 to 12 carbon atoms, nitrile, alkylenenitrile having 2 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, acyl having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, alkylalkenyl having 3 to 12 carbon atoms, arylalkenyl having 8 to 12 carbon atoms or halogen, in which the alkenyl of the above substituent(s) may be introduced with at least one functional group of an epoxide group, an alkoxy group, a hydroxy group and an amine group, provided that at least one of R 1 to R 4 or at least one of R 5 to R 8 is alkenyl having 2 to 12 carbon atoms, alkylalkenyl having 3 to 12 carbon atoms or arylalkenyl having 8 to 12 carbon atoms, in which the alkenyl of the above substituent(s) may be introduced with at least one functional group of an epoxide group, an alkoxy group, a hydroxy group and an amine group; W and W′ are each independently directly bonded, or are each independently oxygen, sulfur, sulfoxide, sulfone, alkylidene having 1 to 30 carbon atoms, alkylene having 2 to 30 carbon atoms, cycloalkylidene having 3 to 30 carbon atoms, cycloalkylene having 3 to 30 carbon atoms or phenyl-substituted alkylene having 2 to 30 carbon atoms; and —OOCYCOO— and —OOCY′COO— are each independently terephthalic acid, isophthalic acid, dibenzoic acid or naphthalene dicarboxylic acid, in which the aromatic group may be substituted with a substituent selected from the group consisting of alkyl having 1 to 8 carbon atoms, aryl, alkylaryl and halogen, and wherein R 9 to R 12 are each independently hydrogen, alkyl having 1 to 12 carbon atoms, arylalkyl having 7 to 12 carbon atoms, aryl having 6 to 12 carbon atoms, nitrile, alkylenenitrile having 2 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, acyl having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, alkylalkenyl having 3 to 12 carbon atoms, arylalkenyl having 8 to 12 carbon atoms or halogen, provided that at least one of R 9 to R 12 is alkenyl having 2 to 12 carbon atoms, alkylalkenyl having 3 to 12 carbon atoms or arylalkenyl having 8 to 12 carbon atoms; and W is directly bonded, or is oxygen, sulfur, sulfoxide, sulfone, alkylidene having 1 to 30 carbon atoms, alkylene having 2 to 30 carbon atoms, cycloalkylidene having 3 to 30 carbon atoms, cycloalkylene having 3 to 30 carbon atoms or phenyl-substituted alkylene having 2 to 30 carbon atoms.