| 摘要 |
A polyolefin composition comprising (parts by weight): A) 50-90% of of polypropylene homopolymer with an isotactic index (percentage by weight of fraction insoluble in boiling n-heptane) higher than 80, preferably between 90 and 98, or crystalline copolymer of propylene with ethylene and/or an alpha-olefin having 4-10 carbon atoms, containing 85% or more of propylene and having an isotactic index equal to or higher than 80; B) 10-50% of Butene-1 (co)polymers having a content of butene-1 units in the form of isotactic pentads (mmmm) from 25 to 70%; intrinsic viscosity [&eegr;] measured in tetraline at 135° C. from 1 to 3 dL/g; a content of xylene insoluble fraction at 0° C. from 3 to 60%. Fibers and spun bond (woven non woven) thereof.
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