| 摘要 |
A polyolefin composition, comprising: (A) from 5 to 95 parts by weight of a crystalline propylene polymer having an isotactic index greater than 80, selected from polypropylene homopolymer and propylene copolymers containing 0.5 to 15 mol % of ethylene and/or an alpha-olefin having 4 to 10 carbon atoms, and (B) from 5 to 95 parts by weight of an ethylene/alpha-olefin copolymer containing from 35 to 70% by weight of ethylene, from 30 to 65% by weight of an olefin CH<SUB>2</SUB>-CHR, in which R a hydrocarbyl radical with 1-12 carbon atoms, and from 0 to 10% of a polyene characterized by (i) a Molecular Weight Distribution expressed by Mw/Mn of higher than 3, (ii) a content of 2-1 regioinvertions of the alpha-olefin units of lower than 5% and (iii) a value of Shore A and content by weight of ethylenic units, calculated on the basis of the whole polymer, such that the point defined by such values falls below the curve defined by the following equation: <?in-line-formulae description="In-line Formulae" end="lead"?>Y=0.0438X<SUP>2</SUP>-4.1332X+A<?in-line-formulae description="In-line Formulae" end="tail"?> where Y is the value of the Shore A, X is the weight percentage of ethylene units in the polymer calculated by NMR and A is 145.
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