Abstract:
Process for the preparation of a polyolefin Olefins of the formula R11—CH═CH—R12 (R11, R12=H or C1-C14-alkyl) are polymerized in the presence of a catalyst consisting of at least one metallocene of the formula I (M=zirconium or hafnium) and an aluminoxane. Polymers having a high molecular weight are obtained in a high yield.
Abstract:
The present invention relates to a catalyst system based on fulvene cyclopentadienyl metal complexes, to a method of producing said catalyst system and to the use thereof for the polymerization and copolymerization of olefins and/or dienes.
Abstract:
Described are certain monocyclopentadienyl Group IV B metal compounds, catalyst systems comprising such monocyclopentadienyl metal compounds and an activator, and a process using such catalyst systems for the production of polyolefins, particularly high molecular weight ethylene-&agr;-olefin copolymers having a high level of &agr;-olefin incorporation.
Abstract:
This invention provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer. This invention also provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer, wherein said catalyst composition comprises a post-contacted organometal compound, a post-contacted organoaluminum compound, and a post-contacted fluorided silica-alumina.
Abstract:
Activator solid support for metallocenes as catalysts in the polymerization of olefins, characterized in that it consists of a group of support particles for a solid catalytic component, which are formed from at least one porous mineral oxide, the said particles having been modified in order to carry, on the surface, aluminium and/or magnesium Lewis-acid sites of formula: or —Mg—F, the groups coming from a functionalization agent having reacted with —OH radicals carried by the base particles of the support, the functionalization reaction having been followed by a fluorination reaction. The catalytic system according to the invention comprises (a) a metallocene catalyst, which has, if required, been subjected to a prealkylation treatment; (b) a cocatalyst; and (c) an activator solid support for metallocene, as defined above, it being possible for the cocatalyst (b) to be absent if the metallocene catalyst (a) has been prealkylated.
Abstract:
The present invention provides a compound catalyst system useful for synthesizing polyethylenes or copolymers of ethylene having bimodal or broad molecular weight distributions, prepared by incorporating an organic alcohol as an electron-donor compound and an aluminoxane compound into the prior art compound catalyst systems, thereby promoting the activities of the two active centers, which leads to not only a large improvement in the activity of the catalyst system, but also the formation of polyethylenes and copolymers of ethylene having bimodal or broad molecular weight distributions, which in turn gives polymers having excellent processability and mechanical properties. A process for preparing the solid catalyst component used in the compound catalyst system according to the present invention and use of the compound catalyst system are also disclosed.
Abstract:
Activator solid support for metallocenes as catalysts in the polymerization of olefins, characterized in that it consists of a group of support particles for a solid catalytic component, which are formed from at least one porous mineral oxide, the said particles having been modified in order to carry, on the surface, aluminium and/or magnesium Lewis-acid sites of formula: functionalization agent having reacted with —OH radicals carried by the base particles of the support, the functionalization reaction having been followed by a fluorination reaction. Also disclosed is a catalytic system including a metallocene catalyst, which has optionally been subjected to a prealkylation treatment; a cocatalyst; and an activator solid support for metallocene, as defined above.
Abstract:
A process of forming a bimetallic catalyst composition comprising a cocatalyst (a trialkylaluminum compound) and a catalyst precursor. The precursor comprises at least two transition metals; a metallocene complex is a source of one of said two transition metals. The precursor is produced in a single-pot process by contacting a porous carrier, in sequence, with a dialkylmagnesium compound, an aliphatic alcohol, a non-metallocene transition metal compound, a contact product of a metallocene complex and a trialkyl-aluminum compound, and methylalumoxane.
Abstract:
The present invention relates to a catalyst composition and a method for making the catalyst composition of a polymerization catalyst and a carbonyl compound. The invention is also directed to the use of the catalyst composition in the polymerization of olefin(s). In particular, the polymerization catalyst system is supported on a carrier. More particularly, the polymerization catalyst comprises a bulky ligand metallocene-type catalyst system.
Abstract:
This invention provides an article, compositions, methods of making and uses of vapor-deposited metal compounds immobilized on porous substrates. The substrate is a porous substrate having an average pore size of at least about 8 Å and a surface area of at least about 10 m2/g. The methods describe the vapor-deposition of an inorganic compound onto the substrate where the deposition is accomplished with a relatively small amount of ligand loss. The substrate can be pre-treated to achieve a uniformly dispersed metal compound deposited on the substrate. The inorganic compound can decompose into a metal compound. The article can also function as a catalyst for carbon-heteroatom coupling reactions such as carbon-carbon coupling reactions, most notably, the Heck reaction.