| 摘要 |
<p>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 α, β and γ (wherein X represents H or Cl, with at least one of them being Cl). In formulae (II) and (III), R?1, RII, and RIII¿ each represent a group selected from among 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 2,7-naphthylene, δ, ε, ζ, and η. 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.</p> |
