| 摘要 |
<p>A biaxially oriented polyester film bearing a layer (A) of a polyester comprising butylene terephthalate units and having a melting point of 240°C or below, wherein the lengthwise edge -tear resistance of the film is smaller than the widthwise edge -tear resistance thereof and the lengthwise and widthwise edge-tear resistances of the film are each 40N or below; a biaxially oriented polyester film which has a crystallization temperature (Tc) of 125°C or above and whose lengthwise and widthwise edge-tear resistances are each 80N or below; and a biaxially oriented polyester film which is a laminate obtained by sandwiching the layer (A) between two films (B) of a polyester having a melting point higher than that of the polyester of the layer(A) by at least 10°C and uniting them, wherein the lengthwise and widthwise edge-tear resistances of the film are each 80N or below and the elongation of the film at break is 50 % or below. These biaxially oriented polyester films are excellent in film-formation stability and exhibit such good hand-cutting property (tearability) as to permit practical use only through lamination with a sealant layer alone, thus being useful as substitutes for current packaging materials including cellophane, moistureproof cellophane, and K-coat cellophane.</p> |
