POLYETHYLENE COMPOSITION WITH MULTIMODAL MOLECULAR WEIGHT DISTRIBUTION FOR BLOW MOULDING ARTICLES AND PREPARATION METHOD THEREOF Russian patent published in 2010 - IPC C08L23/04 C08L23/16 C08F297/08 B29C49/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to a polyethylene composition with multimodal molecular weight distribution for blow moulding canisters with volume ranging from 2 to 20 dm³ and a method of preparing the said composition. The composition has density ranging from 0.950 to 0.958 g/cm³ at 23°C and melt flow rate (MFR_190/5) from 0.30 to 0.50 dg/min. The composition also contains 40 to 50 wt % low molecular weight ethylene homopolymer A and 25 to less than 30 wt % high molecular weight copolymer B obtained from ethylene and another 1-olefin containing 4 to 8 carbon atoms, and 24 to 28 wt % ethylene copolymer C having ultra-high molecular weight.

EFFECT: obtained composition has good resistance to chemical effect, especially high mechanical strength, high corrosion resistance and is a naturally light material; high melt strength of the composition enables prolonged extrusion without breaking the workpiece, and an accurately selected swelling index of the composition enables optimisation of controlling thickness of the wall of the article.

10 cl, 1 tbl, 1 ex