| 摘要 |
<p>The present invention relates to heat-sealable polypropylene films having an improved water vapour barrier action, having the layer structure ABCBA, where a) C, the base layer, comprises highly isotactic polypropylene which has an isotacticity of > 94% and is hydrocarbon resin with a molecular weight of up to about 2000 g/mol and a softening point of above 130@C, b) B are two hydrocarbon resin-free jacket layers of highly isotactic polypropylene having an isotacticity of > 94%, where the ratio between the thickness of the jacket layer and the thickness of the base layer is between 0.01 and 0.1, and c) A are two top layers of a heat-sealable polyolefin homopolymer, copolymer or terpolymer, where these top layers contain at least one antiblocking agent, lubricant and antistatic.</p> |
