Metallocene catalysts and associated methods of preparation and use
申请人:SRI International
公开号:US05892079A1
公开(公告)日:1999-04-06
Novel metallocene compounds are provided which are useful as polymerization catalysts, particularly in the polymerization of addition polymerizable monomers such as olefinic or vinyl monomers. Preferred polymer compositions prepared using the novel catalysts are bimodal or multimodal in nature, typically having a bimodal or multimodal molecular weight distribution. The metallocenes are binuclear or multinuclear, and contain two or more chemically distinct active sites. Methods for synthesizing the novel catalysts are also provided, as are methods for using the novel compounds as homogeneous or heterogeneous polymerization catalysts.
Novel metallocene compounds are provided which are useful as polymerization catalysts, particularly in the polymerization of addition polymerizable monomers such as olefinic or vinyl monomers. Preferred polymer compositions prepared using the novel catalysts are bimodal or multimodal in nature, typically having a bimodal or multimodal molecular weight distribution. The metallocenes are binuclear or multinuclear, and contain two or more chemically distinct active sites. Methods for synthesizing the novel catalysts are also provided, as are methods for using the novel compounds as homogeneous or heterogeneous polymerization catalysts.
Preparation of multimodal polymer compositions using multinuclear
申请人:SRI International
公开号:US05986024A1
公开(公告)日:1999-11-16
A process is provided for preparing polymer compositions which are multimodal in nature. The process involves contacting, under polymerization conditions, a selected addition polymerizable monomer with a metallocene catalyst having two or more distinct and chemically different active sites, and a catalyst activator.