| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin retardation film which can develop desired retardation. SOLUTION: The retardation film comprises a thermoplastic resin, wherein the thermoplastic resin has the maximum strain hardening parameter (λn) satisfying the following relation, the parameter represented by the ratio of uniaxial elongational viscositiesη<SB>A</SB>,η<SB>B</SB>with respect to elongational strains A, B at optional two points measured at an elongational strain rate of 0.1 S<SP>-1</SP>at a temperature higher by 50°C than the glass transition temperature of the thermoplastic resin. The relation is:λn=η<SB>B</SB>/η<SB>A</SB>=5.0 to 80.0 at B/A=1, wherein A, B represent elongational strains of a sample on measurement, and the elongational strain A is within the range of 0.1 to 0.3. COPYRIGHT: (C)2007,JPO&INPIT |
