Olefin! polymerisation catalyst with chromium component - on anhydrous magnesium di:halide support forming linear polymers of increased intrinsic viscosity

摘要

Olefin polymerisation catalyst comprises the reaction prod. of (a) organometallic cpd. including hydrides of Gp. I, II or III and (b) prod. obtd. by contacting an anhydrous Cr cpd. with an anhydrous Mg dihalide support formed in situ, the Cr cpd. being present in amts. 50 wt.% based on the Mg cpd. The support has specific surface >3 m2/g and component (b) has a specific surface >3 m2/g and/or an X-ray spectrum with a halo in place of the lines of strongest intensity present in the spectrum of a normal non-activated Mg halide powder. The catalyst is esp. used for the homo-or copolymerisation of ethylene at -80 to +200 degrees C opt. in the presence fo an inert liquid. The polymer is linear c.f. the polymer obtd. using Ti based catalysts and has a higher intrinsic viscosity.