| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a retardation film such as a half wavelength plate or the like having heat resistance when stored at high temperature. <P>SOLUTION: The retardation film consists of an oriented film containing a lactone compound expressed by formula (I) and a synthetic polymer having a fluorene ring group expressed by general formula (II). The retardation film contains the lactone compound by ≥0.001 wt.% and <3.0 wt.% on the basis of the weight of an aligned film of the synthetic polymer and has excellent thermal stability. In formula (I), each of R<SB>1</SB>and R<SB>2</SB>represent a hydrogen atom and/or a 1-10C alkyl group and Ar<SB>1</SB>is a 6-20C aromatic group which may have a substituent. In formula (II), each of R<SB>3</SB>and R<SB>4</SB>independently represents at least one kind selected from a hydrogen atom, halogen atoms or 1-3C hydrocarbon groups. <P>COPYRIGHT: (C)2004,JPO |
