Abstract:
Especially homogeneous supported Ziegler-Natta catalysts may be prepared in a simple one reaction vessel process from a magnesium hydrocarbyloxy starting material which is soluble in a hydrocarbon solvent. The process comprises: (I) reacting a magnesium hydrocarbyloxy compound with a chlorine-containing compound in a non-polar hydrocarbon solvent in which said magnesium hydrocarbyloxy compound is soluble whereby to produce a solution (A); and then either: (II) contacting the solution (A) with a chlorine containing tetravalent titanium compound to produce a solution (B); (III) impregnating solution (B) into a porous particulate support; or (II) impregnating solution (A) into a porous particulate support; and (III) contacting the solid support with a chlorine containing tetravalent titanium compound; or (II) impregnating solution (A) into a porous particulate support pretreated with a chlorine containing tetravalent titanium compound.
Abstract:
The present invention relates to a solid catalyst component for the polymerization of olefins CH2═CHR in which R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, comprising Mg, Ti, halogen and an electron donor selected from substituted succinates of a particular formula. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give polymers in high yields and with high isotactic index expressed in terms of high xylene insolubility.
Abstract:
Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a triple-decker bimetallic complex. The complex includes two Group 3-10 transition metals and a delocalized dianionic ligand that is pi-bonded to each of the metals. The behavior of the catalysts can be modified by choice of each metal, by the choice of the dianionic ligand, or by choice of the ancillary ligands. The invention provides a new way to make a large variety of catalyst systems.
Abstract:
The present invention relates to a catalyst for homo- or co-polymerization of ethylene, or more particularly to a solid titanium catalyst supported on a magnesium-containing carrier, having high catalytic activity and excellent polymerization properties, which can provide polymers of high bulk density and reduce the amount of polymers dissolvable in a medium during polymerization.
Abstract:
A catalyst system for the polymerization of ethylene, comprising a particulate inorganic oxide supporting a chromium oxide being in a reduced oxidation state and a metallocene compound having the formula Cp2ZrR′R″, wherein each Cp, being equal or different, is an unsubstituted or substituted cyclopentadienyl compound, and R′ and R′, independent of each other, are selected from the group comprising alkyls having 1 to 6 carbon atoms, unsubstituted or substituted benzyl, and phenoxy substituted with alkyls having 1 to 6 carbon atoms; or R′ or R″ may be a halide. The catalyst system is prepared by a method comprising the steps of calcining the support, joining onto the surface of the support a chronium-organic compound, subjecting the obtained catalyst precursor to oxidizing conditions to obtain the chromium in an oxidized state, reducing the oxidized chromium to obtain a main part thereof in a bivalent oxidation state, and contacting the reduced catalyst with the metallocene compound.
Abstract:
A photocatalytic material having titanium oxide crystals and anions X incorporated therein, which is prepared by at least one of a method comprising substituting anions X for some of the oxygen sites of titanium oxide crystals, a method comprising doping anions X between lattices of a titanium crystal and a method comprising doping grain boundaries of titanium oxide, or a combination of these method. The photocatalytic material has acquired a new energy level formed in a band gap of titanium oxide, which results in its exhibition of a photocatalytic activity by absorbing visible lights. The photocatalytic material can thus exhibit a satisfactory photocatalytic activity under sunlight and also in a room with a fluorescent lamp.
Abstract:
Process of preparing silica-supported catalysts. A support material comprising silica particles impregnated with an alumoxane co-catalyst with at least one-half of the co-catalyst disposed within the internal pore volume of the silica is contacted with a dispersion of a metallocene catalyst in an aromatic solvent. The dispersion and support are mixed at a temperature of about 10° C. or less to enable the metallocene to become reactively supported on and impregnated within the alumoxane-impregnated silica particles. The supported catalyst is recovered from the aromatic solvent and washed with an aromatic hydrocarbon and then a paraffinic hydrocarbon at a temperature of about 10° C. or less. The washed catalyst is dispersed in a viscous mineral oil.
Abstract:
A gas treatment device, comprises a substrate disposed within a shell. The substrate comprises a catalyst composition comprising a support, a catalyst, and a sufficient amount of SMSI material such that, upon exposure to a gas stream (at a gas treatment device operating temperature), less than or equal to about 35 wt % of hydrocarbons in the gas stream are burned. A method for forming a gas treatment device, comprises applying a slurry to a substrate, wherein the slurry comprises a support and a sufficient amount of SMSI material such that, upon exposure to a gas stream at a gas treatment device operating temperature, greater than or equal to about 50 wt % of hydrocarbons in the gas stream are cracked to a light fraction; applying a catalyst to the substrate; calcining the catalyst; and disposing the calcined substrate into a shell, with a retention material disposed between the shell and the calcined substrate.
Abstract:
A reductive system including a silane, preferably PMHS, and an active zinc compound, which is monomeric and not a hydride, wherein a reduction of a carbonyl substrate to a corresponding alcohol is achievable.
Abstract:
Organolead compounds such as tetraethyllead are useful in catalyst compositions for the oxidative carbonylation of hydroxyaromatic compounds to diaryl carbonates. They are employed in combination with a Group 8, 9, or 10 metal such as palladium, or a compound thereof, and a bromide or chloride such as tetraethylammonium bromide.