| abstract |
Heat resistance is high, even if it is a single layer structure, it is excellent in moldability and handling property, and the retardation Rth in the thickness direction shows a negative value, and a retardation film preferable as a negative A plate or a positive C plate, and a method for producing the same are provided. This retardation film is formed from a stretched film of a polyester resin, the diol unit (A) contains the unit (A1) represented by the following formula (1), and the dicarboxylic acid unit (B) is represented by the following formula ( It contains the unit (B1) represented by 2a) or (2b), and is a negative A plate or a positive C plate. (Wherein, Z 1 and Z 2 represent an aromatic hydrocarbon ring, R 1 , R 2a , R 2b , R 3a and R 3b represent a substituent, k, p1 and p2 represent an integer of 0 to 8, and q Represents an integer of 0 to 4, m1, m2, n1 and n2 represent an integer of 0 or more, A 1a and A 1b represent an alkylene group, and A 2a , A 2b and A 3 represent a divalent hydrocarbon group.) |