Patent ID: 6376613
Filing Date: 2002-04-23
Classification: C08L

Abstract:
A thermoplastic composition comprising:(A) from 1 to 99% by weight of an amorphous propylene polymer having the following characteristics: (i) intrinsic viscosity greater than 1 dl/g; (ii) percentage of syndiotactic diads (r) minus percentage of isotactic diads (m) greater than 0; (iii) less than 2% of the CH2 groups contained in the sequences (CH2)n, with n greater than or equal to 2; (iv) Bernouillianity index (B)=1Â±0.2; (v) melting enthalpy value lower than 10 J/g; and (vi) a ratio of Mw/Mn lower than 4; and (B) from 1 to 99% by weight of a component BII having the following composition: (a) 10-50% by weight of at least one polymer selected from the group consisting of propylene homopolymers having an isotactic index higher than 80, and copolymers of propylene with at least one comonomer selected from ethylene and the &agr;-olefins of formula CH2&boxH;CHR wherein R is an alkyl radical containing from 2 to 8 carbon atoms, said copolymer containing at least 85% by weight of units deriving from propylene, (b) 0-20% by weight of a copolymer containing ethylene, insoluble in xylene at room temperature, and (c) 40-80% by weight of a copolymer containing 10-40% by weight of units deriving from ethylene, 90-60% by weight of units deriving from at least one comonomer selected from the group consisting of propylene and the &agr;-olefins of formula CH2&boxH;CHR wherein R is an alkyl radical containing from 2 to 8 carbon atoms, and 0-5% of units deriving from a diene, said copolymer being soluble in xylene at room temperature and having an intrinsic viscosity from 1.5 to 4 dl/g; wherein the sum of components (b) and (c) is from 50 to 90% by weight of the polyolefinic composition and the ratio of the amounts by weight of components (b)/(c) is lower than 0.4.