| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyethylene terephthalate resin film in which its dimensional change in a heat treatment process during post-processing is suppressed and which is good in planarity, cuttability, and thickness and reduced in injury. SOLUTION: In the polyethylene terephthalate resin film, the differenceΔn<SB>ab</SB>between the refractive index in the angle direction at 45°to the winding direction and the refractive index crossing at right angles is 0.015-0.060, HS150 in the longitudinal direction is -0.25-0.25%, the difference of HS150 (thermal contraction difference) in the width direction is≤0.1%, HS180 in the longitudinal direction is≥0.4% and <1.15%, the difference (thermal contraction difference) of HS180 in the width direction is≤0.10%, each of the ratios TS/TE between rupture strength and rupture elongation in the four directions is 0.6-2.6 (MPa/%), the rate of thickness change is≤6%, and the thickness is 70-400μm. A method for producing the film is disclosed. COPYRIGHT: (C)2009,JPO&INPIT |
