| 摘要 |
PURPOSE:To provide a drawn tape excellent in resistance to thermal shrinkage and appearance after wound and small in weaving deterioration, made from polyethylene terephthalate having intrinsic viscosity of specified range and polypropylene having melt flow rate of specified range. CONSTITUTION:A blend of (A) 80-95 (pref. 82-93)wt.% of polyethylene terephthalate 0.7-1.1 (pref. 0.8-1.0) in intrinsic viscosity. (B) 20-5 (pref. 18-7)wt.% of polypropylene (pref. homopolymer) 1-10 (pref. 1.5-8)g/10min in melt flow rate, and, if needed, (C) such ingredient(s) as thermal stabilizer, light stabilizer, anti-blocking agent, etc., is kneaded in a molten state to make a composition, which is then formed into film using e.g. a T-die. The film is then slit at specified width into tapes. The tape is then drawn, along with heat treatment, in the machine direction by a factor of ca.4-8 at elevated temperatures using a drawing machine, thus obtaining the objective tape. |
