TUBE, HAVING HIGH HEAT RESISTANCE AND USE OF POLYETHYLENE COMPOSITION IN MAKING SAID TUBE

摘要

FIELD: chemistry.;SUBSTANCE: composition contains basic polyethylene resin making up at least 90 wt % of all the composition and having time to failure equal to at least 250 hours measured according to ISO 1167 at 95°C and 4.3 MPa. The basic resin contains a copolymer of ethylene with alpha-olefin, containing 4-20 carbon atoms, as fraction (A) and a homopolymer of ethylene or copolymer of ethylene with alpha-olefin, containing 4-20 carbon atoms, as fraction (B). Fraction (A) has lower molecular weight than fraction (B). Density of the basic resin is lower than 940 kg/cm³, and melt flow rate (MFR5) at 190°C/5.00 kg is equal to at least 0.20 g/10 min.;EFFECT: higher pressure resistance at high temperature, as well as improved flexibility of the tube.;12 cl, 1 tbl, 2 ex