| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a retardation film having optical durability in addition to superior orientation. <P>SOLUTION: In the retardation film composed of a polymer (except cellulose-based polymers) oriented film, the polymer contains a monomer unit having a positive or negative intrinsic birefrigence (first monomer unit) and at least one monomer unit having an intrinsic birefrigence of the same symbol as the first monomer unit (second monomer unit), a homopolymer of the first monomer unit satisfying the following formula (1): R<SP>1</SP><SB>450</SB>/R<SP>1</SP><SB>550</SB><1 (1), wherein R<SP>1</SP><SB>450</SB>represents a phase difference of a homopolymer composed of the first monomer units, which is measured at wavelength 450 nm, and R<SP>1</SP><SB>550</SB>represents the phase difference of a homopolymer composed of the second monomer units, which is measured at wavelength 550 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT |
