Abstract: A polyimide resin has an acid dianhydride-derived structure and a diamine-derived structure, the acid dianhydride contains an acid dianhydride represented by the general formula (1) and a fluorine-containing aromatic acid dianhydride, and the diamine contains a fluoroalkyl-substituted benzidine. In the general formula (1), n is an integer of 1 or more, and R1 to R4 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a perfluoroalkyl group having 1 to 20 carbon atoms. The content of the acid dianhydride represented by the general formula (1) may be 10 to 65 mol %, and the content of the fluorine-containing aromatic acid dianhydride may be 30 to 80 mol %, based on 100 mol % of the total of the acid dianhydride.

Abstract: Provided is a polymer material containing at least one kind of a cellulose derivative having (a) an organosilyl group (the organosilyl group having a first aliphatic group, an unsaturated aliphatic group, or an aromatic group), and (b) an acyl group or a second aliphatic group.

Abstract: Provided are: a novel retardation film which has low photoelastic coefficient, while having good linear thermal expansion coefficient and water absorption; and the novel retardation film which additionally has high heat resistance. The above-described problem is solved by a retardation film which has an absolute value of the linear thermal expansion coefficient of 100 ppm/° C. or less, a glass transition temperature of 180° C. or more, a photoelastic coefficient of from 5×10?12 m2/N to 30×10?12 m2/N and a water absorption of 2.0 wt % or less, or a retardation film which has an absolute value of the linear thermal expansion coefficient of 100 ppm/° C. or less, a photoelastic coefficient of from 5×10?12 m2/N to 30×10?12 m2/N and a water absorption of 2.0 wt % or less.

Abstract: Provided is a polymer material containing at least one kind of a cellulose derivative having (a) an organosilyl group (the organosilyl group having a first aliphatic group, an unsaturated aliphatic group, or an aromatic group), and (b) an acyl group or a second aliphatic group.