| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-toughness sequentially biaxially-stretched optical film which exhibits negative birefringence, excels in heat resistance, mechanical characteristics and optical characteristics, and excels in toughness (elongation) particularly in an arbitrary direction in a film surface, and a method for producing the same. SOLUTION: The high-toughness sequentially biaxially-stretched optical film comprises 15-75 wt.% of a copolymer (a) comprising anα-olefin residue unit and an N-phenyl substituted maleimide residue unit in a molar ratio of 49:51 to 35:65 and having a weight average molecular weight of 5×10<SP>3</SP>-5×10<SP>6</SP>, and 85-30 wt.% of an acrylonitrile-styrene copolymer (b) having a weight average molecular weight of 5×10<SP>3</SP>-5×10<SP>6</SP>, and the optical film has a tensile breaking elongation of≥5% in directions parallel to the respective stretching directions. The method for producing the same is also provided. COPYRIGHT: (C)2009,JPO&INPIT |
