摘要 |
<P>PROBLEM TO BE SOLVED: To provide a biaxial stretched polyethylene terephthalate based resin film preferable for a base film of a laminated body. Ž<P>SOLUTION: The polyethylene terephthalate based resin film has a difference Δn<SB>ab</SB>between a refractive index of a direction forming an angle of 45° with a longitudinal direction of the film and a refractive index of a direction forming an angle of 90° to it of 0.015-0.060, and satisfies the following requirements (1)-(5). (1) An average of height of warps of the four corners when it is heat-treated at 150°C for 30 min is 0.5-5.0 mm, (2) HS150 is -0.25% to 0.25%, (3) difference in a width direction of HS150 is not more than 0.10%, (4) HS180 is 0.4% to less than 1.15%, and (5) difference in the width direction of HS180 is not more than 0.10%. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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