| 摘要 |
<p>The polypropylene composite film of the present invention comprises (A) a crystalline polypropylene layer and (B) a propylene-1-butene random copolymer layer which is laminated on at least one surface of the crystalline polypropylene layer (A). The propylene/1-butene random copolymer (B) has the following properties: (1) the copolymer comprises 50 to 95 % by mol of constituent units derived from propylene and 50 to 5 % by mol of constituent units derived from 1-butene, (2) the intrinsic viscosity is 0.1 to 5 dl/g, (3) the molecular weight distribution (Mw/Mn) is not less than 3, and (4) the parameter B value is 1.0 to 1.5. The crystalline polypropylene layer (A) of this composite film may be unstretched, monoaxially stretched or biaxially oriented. The polypropylene composite film has excellent heat-sealing properties, such as low-temperature heat-sealing properties and heat-sealing strength, and hot tack properties. The polypropylene composite film is almost free from surface tackiness and shows good slip properties and high blocking resistance at high temperatures, so that it is suitable for high-speed packaging. In addition, this composite film also has good transparency and scratch resistance. The polypropylene composite film of the invention having the above-mentioned excellent properties can be favorably used for packaging of foods, fill packaging and fiber packaging.</p> |
