| 摘要 |
This composition comprises a mixture of 20 to 70 parts by weight of polynorbornene, from 80 to 30 parts by weight of a crystalline polyolefin and of an amount of plasticiser of the polynorbornene sufficient to lower its glass transition temperature to the rubber range. According to the invention, there is chosen, as crystalline polyolefin, a mixture of a copolymer of ethylene and of at least one alpha -olefin having from 3 to 10 carbon atoms, the said copolymer having a density of between 0.89 and 0.93, a degree of crystallinity of between 15 and 50 % and a melt index of between 0.5 and 15 dg/min, and of a copolymer of ethylene and of at least one alkyl acrylate in which the alkyl group has from 1 to 8 carbon atoms, the said copolymer having a melt index of between 0.1 and 20 dg/min. Concrete applications of these compositions comprise especially flexible tubing, seals for the building and automobile industries, dust boots (dust-protection bellows) for the automobile industry, injected articles, such as solid wheels for the toy industry, and the like.
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