Patent ID: 6461703
Filing Date: 2002-10-08
Classification: C08L,F16L,Y10T

Abstract:
A polyolefin composition comprising:(A) 60-90% by weight of at least one heavy mineral filler with a specific weight greater than or equal to 3; (B) 10-40% by weight of a non-crosslinked heterophasic polyolefin composition; and (C) a compatibilizer for fillers in quantities ranging from 0.1% to 4% by weight with respect to the weight of components (A)+(B): said composition (B) being characterized in that it comprises (weight percentages):1Â°) 30-60% of a propylene homopolymer fraction with an insolubility in xylene at ambient temperature of greater than 80%, or a copolymer of propylene with ethylene or a C4-C10 &agr;-olefin or combinations thereof, containing more than 80% of propylene, and having an insolubility in xylene at ambient temperature of greater than 80% (Fraction 1Â°); 2Â°) 40-70% of a copolymer fraction of ethylene with propylene or a C4-C10 &agr;-olefin or combinations thereof, and optionally minor quantities of diene; said copolymer containing from 15 to 70% of ethylene, and being soluble in xylene at ambient temperature (Fraction 2Â°); and 3Â°) 0-30%, with respect to the sum of Fractions (1Â°) and (2Â°), of a copolymer fraction of ethylene with propylene or a C4-C10 &agr;-olefin or combinations thereof, containing at least 75% of ethylene, said fraction being insoluble in xylene at ambient temperature (Fraction 3Â°); wherein the polyolefin composition comprising components (A), (B), and (C) has a flow index from 0.5 to 10 g/10 minutes, an elongation at break of from over 100% to 800%, and a flexural modulus from 100 to less than 3,000 MPa.