摘要:
Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component, This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.
摘要:
The present invention is directed to processes of polymerizing olefin monomers and copolymerizing olefin monomer(s) with functionalized alpha-olefin monomers in the presence of certain late transition metal pyrrolaldimine chelates, especially bidenate or in the presence of a combination of a transition metal in its zero valence and a pyrrolaldimine represented by the formula: wherein each R1, R2, R3, R4, R5, R6, M and L are defined in the specification herein below.
摘要:
The present invention generally relates to ruthenium and osmium carbene catalysts for use in olefin metathesis reactions. More particularly, the present invention relates to Schiff base derivatives of ruthenium and osmium carbene catalysts and methods for making the same. The inventive catalysts are generally prepared by the treatment of unmodified catalysts with the salts of the desired Schiff base ligands, in which an anionic and a neutral electron donating ligands of the unmodified catalysts are simultaneously replaced. The Schiff base derivatives of the ruthenium and osmium carbene catalysts show unexpectedly improved thermal stability while maintaining high metathesis activity, even in polar protic solvents. Although the inventive catalysts may be used in all metathesis reactions, use of these catalysts for ring-closing metathesis ("RCM") reactions is particularly preferred.