The present invention relates to a catalyst system comprising a transition metal compound on a solid carrier which is a surface-reacted calcium carbonate. The invention further relates to a method for manufacturing said catalyst system and to its use in heterogeneous catalysis.

The invention provides a process for preparing an alcohol by hydrogenating an ester which is obtained by alkoxycarbonylating a C2 to C20 hydrocarbon having at least one multiple bond, preferably having at least one olefinic double bond, in which the homogeneous catalyst system used is separated from the product mixture by means of membrane separation. In a development of the present invention, the ester thus formed is converted to another ester by transesterification and then hydrogenated.

A method for producing polyurethanes containing alkoxysilane groups comprises the step of reacting a compound containing at least one NCO group with a compound containing at least one Zerewitinoff-active H atom in the presence of a catalyst component, wherein the compound containing at least one NCO group and/or the compound containing at least one Zerewitinoff-active H atom contain at least one alkoxysilane group, to obtain a polyurethane containing alkoxysilane groups. The invention also relates to a polymer containing alkoxysilane groups, a method for producing a curable polymer, a curable polymer, a cured polymer, and the use thereof. The polymers contain a complex of a lanthanide with at least one beta-diketonate ligand, preferably Yb(acac).sub.3, and are free from organic tin compounds.

The invention relates to a method for preparing a silane-terminated polymer by reacting a polyol A) with a diisocyanate B), an isocyanatosilane C) and an amino silane E), wherein the polyol component A) is reacted simultaneously with a mixture of at least one diisocyanate B) and one isocyanatosilane C), and the resulting product is subsequently reacted with the amino silane E) to produce the silane-terminated polymer. The method according to the invention can be used to prepare mixed silane-terminated polymers having a low viscosity.

The present invention relates to a method for oligomerizing olefins, including the steps of: carrying out an oligomerization reaction of olefins by injecting an oligomerization transition metal catalyst, a cocatalyst, an olefin monomer and a solvent into a reactor; and injecting, into the reaction product of the oligomerization reaction, a catalyst inactivator including a gaseous inorganic material that contains oxygen.

The present invention is directed at stabilization of aqueous urea solutions containing organometallic catalyst precursors. Stabilization can be achieved by monitoring and controlling the solution pH.

A polyvinyl alcohol is produced in a method comprising: a polymerization step comprising polymerizing vinyl ester monomers by controlled radical polymerization in the presence of a radical initiator and an organic cobalt complex to obtain a polymer solution containing a polyvinyl ester; an extraction step comprising extracting a cobalt complex from the polymer solution by contacting an aqueous solution containing a water-soluble ligand with the polymer solution; and a saponification step comprising saponifying the polyvinyl ester after the extraction step to obtain a polyvinyl alcohol. A method for producing a polyvinyl alcohol is thus provided that has a narrow molecular weight distribution and a high number-average molecular weight with good hue and further good solubility in water.

Disclosed are a catalyst system capable of selectively oligomerizing olefins including ethylene and a method for preparing an olefin oligomer by using the same and, specifically, a novel catalyst system capable of trimerizing and tetramerizing olefins, unlike olefin oligomerization catalyst systems that have been reported so far, and a method for preparing an olefin oligomer by using the same. The present invention provides a catalyst system for olefin oligomerization, the catalyst system comprising: a ligand compound represented by chemical formula 1; a chromium compound; a metal alkyl compound; and an aliphatic or alicyclic hydrocarbon solvent.

A liquid phase selective oxidation process is described. The process involves the partial oxidation of alkanes to partially oxidized products. A lower alkane, a solvent, and a soluble metal catalyst are contacted in the presence of an oxidizing agent in a reaction zone under partial oxidation conditions to produce the partially oxidized products. The partially oxidized products include one or more of lower alkyl alcohols, lower alkyl ketones, and lower alkyl acetates. The soluble metal catalyst is a soluble metal salt of cobalt, manganese, chromium, titanium, copper, nickel, vanadium, iron, molybdenum, tin, cerium, zirconium, or combinations thereof, and the promoter comprises a bromine source, an imide source, or combinations thereof.

Markovnikov-selective palladium catalyst for carbonylation of alkynes is formed from a bisphosphite having formula (1): ##STR00001## The carbonylation catalyst is suited for the preparation of a branched heteroarene-keto product from an alkyne substrate, CO and heterocycle in high yields with low amounts of the linear product.