| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially stretched resin film in which the occurrence of a rainbow pattern is suppressed in the inspection of a cross-Nicols method. SOLUTION: In the biaxially stretched resin film, layers each containing a polyethylene terephthalate based resin (A) and layers each containing a syndiotactic polystyrene based resin (B) are laminated alternately to form at least five layers, the absolute value of retardation measured by a polarization microscope using a Berek compensator is 500 nm or below, after a biaxially stretched film of 10 mm<SP>2</SP>is held between two cover glass sheets, melt-pressed at 290°C, and quenched, 20 view fields are observed with a 100-power phase difference microscope, and the number of particles of at least 5μm per 2.4 mm<SP>2</SP>counted with an image analyzer is 30 or below. Preferably, the mass ratio of the polyethylene terephthalate based resin (A) to the syndiotactic polystyrene based resin (B) is 10/90-90/10. COPYRIGHT: (C)2008,JPO&INPIT |
