POLYETHYLENE COMPOSITION FOR BLOW MOULDING, MEANT FOR MAKING LARGE CONTAINERS Russian patent published in 2009 - IPC C08L23/04 C08L23/16 C08F297/08 B29C49/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to a polyethylene composition with multimodal molecular weight distribution, which is specially suitable for blow moulding large containers with volume ranging from 10 to 150 dm³ (l). The composition has density which ranges from 0.949 to 0.955 g/cm³ at 23°C and melt flow rate (MFR_190/5) from 0.1 to 0,3 dg/min. The composition contains from 38 to 45 wt % homopolymer of ethylene A with low molecular weight, from 30-40 wt %, copolymer B with high molecular weight, obtained from ethylene and another 1-olefin, containing 4 to 8 carbon atoms, and from 18 to 26 wt % copolymer C with ultra-high molecular weight. The composition has Izod impact strength with notch (from ISO) from 30 to 60 kJ/m² and resistance to bursting under stress (FNCT) from 60 to 110 hours.

EFFECT: large blow moulded objects made from the composition have high mechanical strength.

9 cl, 1 tbl, 1 ex