| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of an acrylic film excellent in quality, productivity and optical isotropy, and the acrylic film using it. SOLUTION: The manufacturing method of the acrylic film, which is obtained substantially within 30 min after a film with a thickness of 20-80μm comprising an acrylic polymer is cast, has a process (1) an organic solvent solution of the acrylic polymer is cast on a base material and dried until the cast solution shows self-supporting properties, a process (2) the self-supporting film of the acrylic polymer is peeled from the base material, a process (3) the self-supporting film is heat-treated under a condition satisfying formulae (A)-(B) when the glass transition temperature of the acrylic polymer is set to Tg(°C), the heat treatment temperature thereof is set to T<SB>1</SB>(°C) and the heat treatment time is set toθ<SB>1</SB>(s) using a method for grasping both ends of the self-supporting film by a tenter or a method for bonding a heat-resistant tape to both ends of the self-supporting film to reinforce the film and a process (4) the heat-treated film is stretched under a condition satisfying (D)-(H) when the stretching temperature of the film is set to T<SB>2</SB>(°C), the stretching time thereof is set toθ<SB>2</SB>(s) and the stretching factor thereof is set to E<SB>2</SB>(times). COPYRIGHT: (C)2007,JPO&INPIT |
