| abstract |
A retardation film according to the present invention is formed by combining a polyester resin exhibiting negative orientation birefringence and with a phase difference exhibiting normal wavelength dispersibility, and a polyamide resin exhibiting positive orientation birefringence and with a phase difference exhibiting a flat dispersibility. The polyester resin includes a constituent unit having a fluorene-9,9-diyl group, and the polyamide resin may include a constituent unit having an alicyclic skeleton. The polyester resin may include at least one type of constituent unit selected from a fluorenedicarboxylic acid unit (A1) including a unit represented by formula (1), and a fluorenediol unit (B1) including a unit represented by formula (2). (In the formulas, R1 and R2 denote substituent groups, k and m are integers of 0-8, X1a, X1b, X2a, and X2b denote hydrocarbon groups, A1a and A1b denote alkylene groups, and n1 and n2 are integers of 0 or higher.)　The retardation film exhibits both high phase difference expressibility and reverse wavelength dispersibility. |