POLYETHYLENE FOR INJECTION MOULDING Russian patent published in 2010 - IPC C08F10/02 C08L23/06 C08L23/08 B29L31/56 

FIELD: chemistry.

SUBSTANCE: invention relates to polyethylene and articles made by injection moulding polyethylene. Polyethylene contains homopolymers of ethylene and/or copolymers with ethylene with molecular weight distribution M_w/M_n between 3 and 30, density of 0.945 - 0.965 g/cm³, average molecular weight M_w between 50000 g/mol and 200000 g/mol, high-load melt index (HLMI) between 10 and 300 g/10 min. The polymer contains 0.1-15 branches/1000 carbon atoms, where 1-15 wt % polyethylene with the highest molecular weight has degree of branching greater than 1 branch of side chains with length greater than CH₃/1000 carbon atoms.The polyethylene is obtained using a catalyst composition which contains at least two different polymerisation catalysts, where A) is at least one hafnocene-based polymerisation catalyst (A2), and B) is at least one polymerisation catalyst based on an iron component, having a tridentate ligand which contains at least two ortho-, ortho-disubstituted aryl radicals (B). The disclosed polyethylene can be subjected to processing treatment on standard injection moulding apparatus.

EFFECT: articles obtained through injection moulding is uniform and can further be improved by increasing rate of injection moulding or high melting point.

9 cl, 2 tbl, 2 ex