フマル酸ジイソプロピル−ケイ皮酸共重合体およびそれを用いた位相差フィルム

摘要

PROBLEM TO BE SOLVED: To provide a novel diisopropyl fumarate-cinnamic acid copolymer which is expected to provide a retardation film having excellent optical characteristics such as a large refractive index in a direction of film thickness and outer phase difference, a large outer phase difference even in a thin film, and the like; and a retardation film using the same.SOLUTION: Provided is a diisopropyl fumarate-cinnamic acid copolymer comprising diisopropyl fumarate residue units and cinnamic acid residue units.