METHOD FOR CO-POLYMERIZATION OF OLEFINS WITH BRIDGING HAFNOCENES Russian patent published in 2004 - IPC

FIELD: organic chemistry, chemical technology, polymers. SUBSTANCE: invention relates to methods for polymerization of olefins using hafnocene catalytic complexes. Invention describes method of polymerization in preparing ethylene copolymers with density from about 0.850 to about 0.930. Method involves addition of ethylene and one or some co-monomers able to polymerization by incorporation in contact with hafnocene catalytic complex with bridging linkage and this process is carried out under homogeneous polymerizating conditions at reaction temperature in the range 60-225 C. Hafnocene catalytic complex with bridging linkage is derived among: A) bicyclopentadienyl hafnium-containing metalloorganic compound comprising: 1) at least one unsubstituted cyclopentadienyl ligand or cyclopentadienyl ligand substituted with aromatic condensed rings; II) one cyclopentadienyl ligand substituted with aromatic condensed rings and III) covalent bridge binding both cyclopentadienyl ligands being such bridge comprises one carbon or silicon atom with two aryl groups wherein each group is substituted with C₁-C₂- hydrocarbyl or hydrocarbylsilyl group and at least one of these groups represents linear substituent C₃ or with more number of carbon atoms; B) activating co-catalyst. Invention describes method providing preparing high-molecular mass copolymers. EFFECT: improved co-polymerization method. 18 cl, 3 tbl, 9 ex