Retardation film and applications thereof

Abstract

A retardation film includes a polyester-series resin exhibiting a negative orientation birefringence and a forward wavelength dispersibility in retardation in combination with a polyamide-series resin exhibiting a positive orientation birefringence and a flat dispersibility in retardation. The polyester-series resin may contain a constitutional unit having a fluorene-9,9-diyl group, and the polyamide-series resin may contain a constitutional unit having an alicyclic skeleton. The polyester-series resin may contain at least one constitutional unit selected from a fluorenedicarboxylic acid unit (A1) containing a unit of the formula (1) and a fluorenediol unit (B1) containing a unit of the formula (2): wherein R1 and R2 each represent a substituent; k and m each denote an integer of 0 to 8; X1a, X1b, X2a, and X2b each represent a hydrocarbon group; A1a and A1b each represent an alkylene group; n1 and n2 each denote an integer of not less than 0. The retardation film has both a high retardation expression and a reciprocal wavelength dispersibility.

Dependencies are inferred from the claim text.