Patent ID: 6770341
Filing Date: 2004-08-03
Classification: C09D,Y10T

Abstract:
Polyethylene molding material having a bimodal molecular weight distribution which has an overall density of >0.948 g/cm3 and an MFI5/190Â° of <0.2 dg/min, characterized in that it comprises an amount of from 35 to 65% by weight of low-molecular-weight ethylene homopolymer A which has a viscosity VNA in the range from 40 to 90 cm3/g, a melt flow index MFI190/2.16 A in the range from 40 to 2000 dg/min and a density dA of &gE;0.965 g/cm3, and an amount of from 35 to 65% by weight of high-molecular-weight ethylene copolymer B which has a viscosity number VNB in the range from 500 to 2000 cm3/g, a melt flow index MFI190/5 B in the range from 0.02 to 0.2 dg/min and a density dB in the range from 0.922 to 0.944 g/cm3, and in that the fraction obtained during a preparative TREF analysis at a temperature of 78Â° C.Â±3 K using p-xylene has an average molecular weight of &gE;200,000 g/mol.