| 摘要 |
<p>A heat-sealing three-layer laminated film having highly sealing properties, which is not easily broken even under reduced pressure, is provided. The said three-layer laminated film is characterized in that three layers including a biaxial orientation film base layer (A) made of crystalline polypropylene, a cushion layer (B) made of olefin polymer film having a melting point lower than that of the base layer (A) and a heat seal layer (C) made of olefin polymer film are laminated in the order to (A), (B) and (C), degrees of surface orientation of the respective layers are within the range of satisfying the following expressions and, when the cushion layer (B) and the heat seal layer (C) are identical in composition with each other, the degree of plane orientation of the cushion layer (B) is smaller than that of the heat seal layer (C). 2.0 </= PA </= 15.0; 0 </= PB </= 3.5; 2.0 </= PC </= 4.0; where PA: the degree of plane orientation of the base layer (A), PB: the degree of plane orientation of the cushion layer (B), PC: the degree of plane orientation of the heat seal layer (C).</p> |
