ИСТИНА

FIELD: chemistry. SUBSTANCE: invention relates to a catalyst system for producing ethylene copolymers in a high-temperature solution, a metallocene complex of formula (I), use of catalyst system and metallocene complex in high-temperature solution polymerisation of olefins at temperature of more than 100 °C and a method of producing an ethylene copolymer. Catalyst system comprises (i) a metallocene complex of formula (I), where M is Hf or Zr, X is halogen or methyl radical, L is a bridging group of formula -SiR8 2-, where each R8 independently represents methyl, ethyl, propyl, isopropyl, tert-butyl or isobutyl, n equals 0, 1 or 2, R1 and R1' are identical or can be different and can be a linear or branched C1-C6-alkyl group, R2 and R2' are identical or different and represent CH2-R9 group, where R9 is H or a linear or branched C1-C6-alkyl group, R5 and R5' are different and can be H or a linear or branched C1-C6-alkyl group OR group, where R is C1-C6-alkyl group, R6 and R6' are identical or different and can represent H or a group C(R10)3, where R10 are identical or different, and R10 can be H or a linear or branched C1-C6-alkyl group, wherein either one pair of R5 and R6 or R5' and R6' form together unsubstituted 5–6-member ring fused with a benzene ring of the indenyl moiety, and remaining residues R5 and R6 or R5' and R6' in case R5 or R5' are an OR group, where R is C1-C4-alkyl group, and in case R6 or R6' represent group C(R10)3, where R10 are identical, and R10 can represent C1-C2-alkyl group, or R5 and R6 and R5' and R6', taken together, form unsubstituted 4–7-member ring condensed with a benzene ring of the indenyl moiety, provided that if R5 and R6, as well as R5' and R6', taken together, form unsubstituted 5–member ring condensed with a benzene ring of the indenyl moiety, then R2 and R2' are not C1-alkyl group; and R7 and R7' can be identical or different and can represent H or a linear or branched C1-C6-alkyl group, (ii) aluminoxane cocatalyst and (iii) boron-containing cocatalyst. Formula (I): Figure 00000036 . EFFECT: catalyst systems have excellent activity, efficiency and stability. 16 cl, 5 tbl, 5 ex