BIAXIALLY ORIENTED POLYESTER FILM FOR USE AS STENCIL PAPER FOR THERMAL STENCIL PRINTING

摘要

A biaxially oriented polyester film: (A) which comprises a composition comprising at least two thermoplastic polyesters; (B) which has at least two melting peaks which satisfy difference between being in range of 5 to 20 DEG C and average of the both melting peak temperature being in range of 200 to 230 DEG C when measured by DSC at a temperature elevation rate of 2 DEG C/min by superimposing a periodic temperature variation of +/-1 DEG C/min; the highest melting peak temperature ( DEG C) and the lowest melting peak temperature ( DEG C); (C) which has on the film plane two crossing directions having a thermal shrinkage factor at 100 DEG C for 10 minutes of 16 to 25 %; and (D) which has a thickness of 0.2 to 7 mu m. This film is suitable for use in a thermosensitive stencil printing base sheet which enables clear character printing and solid printing, is free from nonuniformity in printing thickness, nonuniformity in printing density and wrinkles, and excellent in durability, and has high perforation sensitivity.