TRANSITION METAL COMPLEXES, CATALYST SYSTEM COMPRISING THEREOF, METHOD OF PREPARING POLYOLEFINS, AND POLYOLEFINIC COMPOSITION Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: described is new catalyst precursor which, in combination with current cocatalyst, is used for preparing polyolefins. Catalyst precursor corresponds to formula I: wherein M is zirconium or hafnium; I is substituted or unsubstituted ligand with π-bonds; Q may be identical or different, and they are independently selected from group consisting of -O-, -NR- end- S-; Y is carbon or sulfur atom; Z is selected from group consisting of -NR₂, then Z is -NR₂-; n is 1 or 2, W is monovalent anionic group, if n is 2 or W is divalent anionic group, if n is 1; R are identical and they are selected from group consisting of alkyl or cycloalkyl; B is bridge alkylene group containing from 1 to 10 carbon atoms, and m is 2″.. Described are catalyst for preparing polyolefins, method of preparing polyofins, and polyolefinic composition. EFFECT: catalyst having very high activity. 22 cl, 17 ex, 11 tbl