公开(公告)号：EP0314785A4

公开(公告)日：1989-04-05

申请号：EP86902036

申请日：1986-04-01

Applicant: TORAY INDUSTRIES

Inventor： ITOYAMA KUNIYOSHI - NANGO -CHO ,  HORITA NORIHIRO ,  SEKI SHIGEMI ,  MINAMI SATOYUKI

IPC: B29C55/00 ,  B29C55/12 ,  C08J5/18 ,  C08L67/02

CPC classification number: C08J5/18 ,  B29C55/005 ,  B29C55/12 ,  B29K2067/00 ,  C08J2367/02 ,  C08L67/02 ,  Y10S428/91 ,  C08L67/00

Abstract: Biaxially oriented polyester film, which comprises a polymer blend of polyester (A) having repeating units of general formula (I) and a copolyester (B) having repeating units of the general formulae (I) and (II) and/or (III) and having a flow-initiating temperature of not higher than 350°C and an ability of forming melting anisotropy, with the reduced molar fraction of (II) and (III) based on the total polymer blend being 0.5 to 18 mol %. In formula (I), n represents 2, 4 or 6, R represents alpha, beta and psi (wherein X represents H or Cl, with at least one of them being Cl). In formulae (II) and (III), R1, RII, and RIII each represent a group selected from among 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 2,7-naphthylene, delta, epsilon, phi, and gamma. One crystal surface of polyester (A) is oriented with respect to the film surface with a surface orientation coefficient of 0.75 to 0.95 and a crystal size of 35 to 75 Å in the direction of the crystal surface.