METHOD FOR PRODUCING SYNDIOTACTIC POLYOLEFINS AND SYNDIOTACTIC POLYPROPYLENE Russian patent published in 1997 - IPC

FIELD: organic chemistry, metallocenic catalyst production. SUBSTANCE: method is directed to metallocenic catalyst used for production of syndiotactic polyolefins. Catalyst comprises metallocene with bridge-type bond in which one of cyclopentadienyl rings is substituted in different manner than adjacent ring. It is established that catalyst of this type is highly syndiospecific and forms polymer with new microstructure. Present invention is also directed to used of one or more proposed catalysts in polymerization process. proposed catalyst is normally described by formula: R" (Cp Rn) (CpR'm) Me Q k, wherein each of Cp represents cyclopentadiently ring or substituted cyclopentadiently ring; each of Rn and R'm is identical or different and represents hydrocarbyl radicals containing 1-20 carbon atoms; R" represents structural bridge between two Cp rings and imparts stereorigidity to catalyst; Me represents metal selected from groups, 4B, 5B or 6B of Periodic table of elements; each of Q represents hydrocarbyl radical containing 1-20 carbon atoms or is halogen; 0≅k<3; 0<n<4; 1<m<4 R'm being selected in such manner that (CpR'm) would be ring sterically different from (CpRn). EFFECT: useful method for production of syndiotactic polymers. 7 cl, 4 tbl, 4 dwg