Abstract:
A catalyst solution for polymerizing &agr;-olefins is obtainable by reacting a metallocene compound with an activator compound which can react with the metallocene compound so as to displace a ligand from the central atom and stabilize the resulting cationic complex by a non-coordinating anion as an ion pair, adding one or more &agr;-olefins in a molar ratio of metallocene compound: &agr;-olefins of from 1:1 und 1:100 and mixing with at least 10 parts by volume of an aliphatic hydrocarbon.
Abstract:
Transition metal complexes of the formula (Ia) or (Ib), in which the substituents and indices have the following meanings: M is titanium, zirconium, hafnium, vanadium, niobium or tantalum or an element of the third subgroup of the Periodic Table or of the lanthanoids, X is fluorine, chlorine, bromine, iodine, hydrogen, C1-C10-alkyl, C6-C15-aryl, alkylaryl having 1 to 10 carbon atoms in the alkyl radical and 6 to 20 carbon atoms in the aryl radical, —OR5 or —NR5R6, n is 1, 2 or 3, where n is the valency of M minus the number 2, Z is a three-way bridge and A and A1 are two-way bridges. Process for preparing the transition metal complexes, compounds which are used as intermediates for their preparation, the use of the transition metal complexes for polymerizing olefins, processes for polymerizing olefins, homo- or copolymers of ethylene or of propylene with other C2-C12-alk-1-enes, their use for preparing films, fibers or moldings and the films, fibers or moldings made of these polymers.
Abstract:
Supported inonic metallocene catalyst prepared by a process comprising the following steps; (i) mixing together in a suitable solvent (a) an metallocene complex, (b) an ionic compound comprising a cation and an anion having up to 100 non-hydrogen atoms and containing at least one substituent comprising a moiety having an active hydrogen, and (c) optionally a support material, (ii) treating the mixture obtained in (i) with an organometallic compound, and (iii) addition of a support material if not added in step (i), and (iv) removing the solvent.
Abstract:
Functional polymers containing hydroxyl groups as supports for use with catalysts can increase the activity of these catalysts which results in improved ethylene polymerization. The present invention seeks to provide catalysts with improved activity by incorporating 2-hydroxyethyl methacrylate (HEMA) into the support of the catalyst.
Abstract:
This description addresses a process for the preparation of polyolefins from one or more olefinic monomers comprising combining under polymerization conditions said olefins with the product of combining i) an organometallic catalyst compound and ii) a cocatalyst complex comprising a trialkylsilyl-substituted carbenium cation and a suitable noncoordinating or weakly coordinating anion. These complexes exhibit good solubility in aliphatic solvents such that use in aliphatic solution based polymerization reaction processes can be conducted without the use of aromatic solvents or co-solvents and without the need for slurry means of introduction into chemical reaction environments. High number-average molecular weight polymers and copolymers at high rates of productivity were observed from the use of metallocene catalysts complexes when activated with [(3,5-(Et3Si)2Ph)3C]+[(C6F5)B]− and used in a hexane-based solution polymerization.
Abstract:
Catalysts, catalyst systems and processes for production of alternating copolymers of ethylene and alpha olefins, and to novel classes of atactic and isotactic alternating copolymers of ethylene and alpha olefins, which copolymers include a wide range of crystallinity and exhibit commercially useful properties. Appropriate selection of ligand substituents permit the catalysts to be symmetric or assymetric, resulting in atactic, or isotactic or atactic, respectively, alternating copolymers of ethylene with alpha olefins. The novel class of bridged flourenyl metallocene catalysts of the invention is assymetric structural form interconvert between states during polymerization of ethylene with alpha olefins to produce alternating isotactic or atactic copolymers. Exemplary metallocene components of the inventive catalyst systems comprised bridged cyclopentadienly-fluorenyl complexes of the general formula: in which: M is a Group 3, 4 or 5 Transition metal, a Lanthanide or an Actinide; X and X′ are the same or different uninegative ligands; L is a substituted or unsubstituted cyclopentadienyl (Cp) or indenyl ligand; Flu is a substituted or unsubstituted fluorenyl ligand; and Y is a bridging group. When the Cp ligand is symmetric, atactic alternating E/&agr;-olefin copolymers are produced and when the Cp ligand is assymetric, alternating isotactic or atactic E/&agr;-olefin copolymers are produced.
Abstract:
A catalyst system comprises at least one metallocene and at least one passivated support and preferably at least one cocatalyst. The passivated support is prepared by treating at least one inorganic oxide with at least one organometallic compound, preferably in an inorganic solvent. A polymer having a melting point of ≧158° C., a proportion of reverse insertions of 98.0% can be obtained using this catalyst system.
Abstract:
Disclosed is the homogenous reaction at 40-200° C. of MgX12−nR1OH (where n=2.0-6.4) with TiX24 and a higher (C6-C20) alkyl ester of a carboxylic acid, optionally in the presence of a solvent. In such a completely homogenous reaction, no carrier appears. In order to obtain a product in the liquid stage, the molar ratio between the ester and the MgX12.nR1OH should be at least 0.8/j wherein j is the number of carboxyl groups in the ester. If the ester has two carboxyl groups, for instance, j is 2 and the molar ratio should be at least 0.8/2, that is, 0.4.
Abstract:
Disclosed are polymerization catalyst activator complexes prepared from the reaction of a carbenium salt and Lewis base containing an aromatic group. Also disclosed are polymerization catalyst activator complexes prepared via the reaction of a Group 13 element containing salt including a Lewis base containing an aromatic group and a tritylhalide compound. Also disclosed are polymerization catalyst systems including the activator complex of the invention, and processes for polymerizing olefin(s) utilizing same.
Abstract:
The present invention relates to mixed catalyst system of a Group 15 containing metal catalyst compound, a bulky ligand metallocene-type catalyst compound, and a Lewis acid aluminum containing activator and to a supported version thereof and for their use in a process for polymerizing olefin(s).