POLYETHYLENE COMPOSITION FOR INJECTION MOULDING Russian patent published in 2018 - IPC C08L23/06 C08L23/08 C08F10/02 C08K3/04 

FIELD: technological processes.

SUBSTANCE: invention relates to a polyethylene composition for injection moulding large hollow articles. Polyethylene composition has a density from 0.943 to 1.1 g/cm³ and comprising A) 0.25–50 % by weight of pure carbon or 0.25–50 % by weight of pure carbon and 0.01–10 % by weight of UV stabilizer selected from light-weight stabilizers based on hindered amines, and B) an ethylene polymer containing from 0.7 to 20 CH₃/1,000 carbon atoms. Said polyethylene A) comprises copolymers of ethylene with 1-alkenes, or a mixture of ethylene homopolymers with said copolymers of ethylene with 1-alkenes, which has molar mass distribution width M_w/M_n of from 7 to 15, density of from 0.942 to 0.954 g/cm³, a weight average molar mass M_w of from 20,000 g/mol to 500,000 g/mol, a MIE of from 1.0 to 3.0 g/10 min, a MIF of from 100 to 200 g/10 min and a ratio MIF/MIE of from 40 to 50, where MIE is the melt flow rate at 190 °C with a load of 2.16 kg and MIF is the melt flow rate at 190 °C with a load of 21.6 kg. Polyethylene A) is obtained by polymerization in the presence of a catalyst containing at least two different polymerization catalysts with a single active center.

EFFECT: polyethylene composition according to the invention has improved properties that exclude strong warpage and reduce the amount of molding pressure required to manufacture large hollow articles.

10 cl, 1 tbl, 2 ex