Abstract:
Single site catalysts which contain a transition metal, a cyclopentadienyl may be activated with alumoxanes in the gas, solution or group-containing ligand, and a phosphinimine ligand slurry phase polymerization of olefin. Alumoxanes contain residual aluminum alkyls which may poison the catalysts. The residual aluminum alkyls may be bound and/or removed from the alumoxanes by treatment with carbohydrates such as cellulose, starch or sugar.
Abstract:
A supported catalyst composition comprising: A1) a mixture of aluminum containing Lewis acids of the formulas: [(—AlQ1—O—)z(—AlArf—O—)z′] and (Arfz″Al2Q16−z″) where; Q1 independently each occurrence is C1-20 alkyl; Arf is a fluorinated aromatic hydrocarbyl moiety of from 6 to 30 carbon atoms; z is a number from 1 to 50; z′ is a number from 1 to 50; and z″ is an number from 0 to 6; or A2) a fluorohydrocarbyl-substituted alumoxane compound corresponding to the formula: R1—(AlR3O)m—R2, wherein: R1 and R2 independently each occurrence is a C1-40 aliphatic or aromatic group or a fluorinated derivative thereof or R1 and R2 together form a covalent bond; R3 independently each occurrence is a monovalent, fluorinated organic group containing from 1 to 100 carbon atoms or R1, with the proviso that in at least one occurrence per molecule, R3 is a monovalent, fluorinated organic group containing from 1 to 100 carbon atoms, and m is a number from 1 to 1000; B) a Group 3, 4, or Lanthanide metal complex containing from 1 to 3 &pgr;-bonded anionic or neutral ligand groups; and C) a support.
Abstract:
A method for making single-site catalysts useful for olefin polymerization is disclosed. A nitrogen-functional heterocycle is first deprotonated with an alkyllithium compound, followed by reaction of this anionic ligand precursor with about 0.5 equivalents of a Group 4 transition metal tetrahalide in a hydrocarbon solvent at a temperature greater than about 10° C. to give an organometallic complex-containing mixture. When combined with exceptionally low levels of an activator (e.g., methyl alumoxane), the mixture actively polymerizes olefins to give polymers with a favorable balance of physical properties, including low density and narrow molecular weight distribution.
Abstract:
A catalyst for the polymerization of olefins is disclosed. The catalyst comprises a complex comprising (a) a ligand of the formula X, (b) a group 8-10 transition metal, and optionally (c) a Bronsted or Lewis acid, wherein R1 and R6 are each, independently, hydrocarbyl, substituted hydrocarbyl, or silyl; N represents nitrogen; and A and B1 are each, independently, a heteroatom connected mono-radical wherein the connected heteroatom is selected from Group 15 or 16 of the Periodic Table; in addition, A and B1 may be linked to each other by a bridging group. The complex is attached to a solid support. The solid support, the Bronsted or Lewis acid, and the complex may be combined in any order to form the catalyst. A process for making the catalyst is also described. Olefin polymerization and copolymerization processes are also described.
Abstract:
A prepolymerization catalyst for use in a gas phase polymerization of an olefin or combinations of olefins which comprises (A) a solid catalyst component comprising magnesium, halogen, titanium and an electron donor and having a weight-average particle diameter of 15 to 45 &mgr;m, (B) at least one organoaluminum compound and (C) a prepolymer of an ethylene and/or at least one &agr;-olefin, wherein the molar ratio of aluminum to titanium in the prepolymerization catalyst (Al/Ti ratio) is 3 to 11 (mol/mol), the weight ratio of the prepolymerization catalyst to the solid catalyst component (prepolymerization catalyst/solid catalyst component) is 2 to 35 (g/g), the content of volatile materials (VM) in the prepolymerization catalyst is 2.0% by weight or less, and the intrinsic viscosity [&eegr;] measured in tetralin at 135° C. is 2.0 dl/g or less, and a process for a production thereof. According to the present invention, a prepolymerization catalyst for gas phase polymerization of olefins showing a high activity in gas phase polymerization, not forming aggregates and coarse particles markedly at the time of prepolymerization, having a high bulk density and an excellent fluidity, not causing a marked entraining of prepolymerization catalyst and product powder out of the fluidized bed and nearly completely free from a formation of aggregates, at the time of gas phase polymerization, and giving an olefin polymer having a low content of cold xylene-soluble fraction can be provided.
Abstract:
A catalyst system suitable for preparing substantially terminally unsaturated atactic polymers or copolymers of &agr;-olefins having a number average molecular weight in the range 300-500,000 comprises (A) a metallocene complex and (B) a cocatalyst comprising (i) a Group III Metal alkyl compound and (ii) a triaryl boron compound. Preferred metallocenes are those having alkyl ligands on the metal atom. The preferred Group III metal alkyl compound is triisobutyl aluminum and the preferred triaryl boron compounds is tris(pentafluorophenyl)boron.
Abstract:
A catalyst composition which includes palladium and zirconium is formed as a suspension which can be coated onto a metal strip. The composition is formed by combining palladium nitrate with a solution of an alkyl ammonium hydroxide, and mixing the combination with a hydrous zirconium oxide, to form the suspension. The alkyl ammonium hydroxide is preferably tetramethylammonium hydroxide or tetrabutylammonium hydroxide. Nitric acid may be added to the palladium nitrate. The resulting composition shows superior activity and good adhesion to a metal strip. The composition can catalyze a combustion reaction, as well as a steam reforming reaction.
Abstract:
A catalyst precursor having the formula: AqMLn wherein each A has the formula: M is a metal selected from the group consisting of Group elements; each L is a monovalent, bivalent, or trivalent anion; X and Y are each heteroatoms; Cyclo is a cyclic moiety; each R1 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R1 groups may be joined to form a cyclic moiety; each R2 is a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R2 groups may be joined to form a cyclic moiety; Q is a bridging group; each m is independently an integer from 0 to 5; n is an integer from 1 to 4; q is 1 or 2; and when q is 2, the A groups are optionally connected by a bridging group Z is provided. The catalyst precursor, when combined with an activating cocatalyst, is useful for the polymerization of olefins.
Abstract:
This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for supporting the catalyst of the invention provides for a supported metallocene catalyst formed by vacuum or pressurized impregnation.
Abstract:
Functionalized amine derivatives are prepared by reacting an amine, a carbonyl derivative, and an organoboron compound under mild conditions. Organoboronic acids react with amines and alpha-hydroxy aldehydes to give anti-alpha-amino alcohols with very high diastereoselectivities (>99% de). When optically pure alpha-hydroxy aldehydes are used in this process, no racemization occurs and the products are obtained with very high enantioselectivities (>99% ee). The reaction also works with unprotected glyceraldehyde to give the corresponding amino diol derivatives, while unprotected carbohydrates give the corresponding amino polyols. The chiral amino alcohol products of this process or their derivatives, react further with metals or non-metals to give adducts that are effective catalysts for a variety of asymmetric reactions. Overall, the present invention relies on the facile synthesis of the chiral amino alcohol ligands for the rapid construction of combinatorial libraries of chiral catalysts. These libraries can then be used to identify the most suitable catalyst for a particular asymmetric transformation.