METHOD OF PREPARING LINEAR AVERAGE DENSITY POLYETHYLENE Russian patent published in 1999 - IPC

FIELD: manufacture of plastic materials. SUBSTANCE: linear average density polyethylene is prepared by polymerization of ethylene in gas phase in the presence of catalyst and organoaluminium cocatalyst. Catalyst is essentially titanium tetrachloride, magnesium dichloride and zirconium organoaluminium compound applied onto inorganic substrate which is product of reaction of zirconium tetrachloride with diene and triisobutyl aluminium. Catalyst further comprises product of reaction of nickel dichloride with diene, triisobutyl aluminium and with or without acceptor additive fixed on inorganic substrate. Said additional component makes it possible to regulate melt flow index and vary other properties of polyethylene without decreasing yield of product per catalyst unit. EFFECT: more efficient preparation method. 2 tbl