发明名称 |
Process and catalyst for producing isotactic polyolefins. |
摘要 |
<p>This invention is for a metallocene catalyst component useful in preparing isotactic polyolefins, a catalyst system using this component and a process for polymerizing olefins using the catalyst component. The catalyst component consists of a bridged metallocene in which one of the cyclopentadienyl rings is substituted in a different manner from the other ring. One of the cyclopentadienyl ligands contains a bulky group in one and only one distal position and the other cyclopentadienyl ligand has bilateral or pseudobilateral symmetry. There is a steric difference between the two Cp rings. The catalyst component is a stereorigid metallocene described by the formula: <MATH> wherein each Cp is a cyclopentadienyl or substituted cyclopentadienyl ring; each Rn and R'm is a hydrocarbyl radical having 1-20 carbon atoms; R= is a structural bridge between the two Cp rings imparting stereorigidity to the Cp rings; Me is a transition metal; and each Q is a hydrocarbyl radical or is a halogen. R'm is selected so that (CpR'm) is a sterically different substituted cyclopentadienyl ring than (CpR'n). The use of a metallocene catalyst component with sterically different cyclopentadienyl rings in which one and only one of the distal positions of the cyclopentadienyl rings has a bulky group as a substituent produces isotactic polymer. <IMAGE></p> |
申请公布号 |
EP0537130(A1) |
申请公布日期 |
1993.04.14 |
申请号 |
EP19920870153 |
申请日期 |
1992.09.23 |
申请人 |
FINA TECHNOLOGY, INC. |
发明人 |
EWEN, JOHN A.;ELDER, MICHAEL J. |
分类号 |
C08F4/642;C08F4/60;C08F4/602;C08F4/619;C08F4/6192;C08F4/659;C08F4/6592;C08F10/00 |
主分类号 |
C08F4/642 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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