| 摘要 |
The invention relates to a multilayer polypropylene film produced by coextrusion which has improved barrier properties with respect to water vapour and oxygen and at the same time has good slip properties and low shrinkage values in order to ensure good passage through the machine. The invention accordingly relates to a polypropylene film whose characterising features are that it is built up from a base layer comprising polypropylene and a hydrocarbon resin having a softening point of 140C and has at least one top layer which comprises a) a random ethylene-propylene copolymer having an ethylene content (high or low density) of at most 10% by weight (based on the copolymer) or b) a propylene-1-butene copolymer, preferably having a 1-butene content of from 10 to 15% by weight (based on the copolymer) or c) a propylene-ethylene--olefin terpolymer in which the -olefin preferably has 4 to 10 carbon atoms; butene, pentene and hexene are particularly preferred, or d) a mixture of two or more of the copolymers or terpolymers mentioned under a), b) and c), the top layer(s) as per a), b), c) or d) optionally additionally containing a hydrocarbon resin and the base layer and/or top layer(s) containing at least one antiblocking agent and/or a lubricant. |
