Abstract: An apparatus for continuously preparing substantially halogen-free, in particular chlorine-free, trialkoxysilanes of the general formula I (RO)3SiH  (I) in which R is an alkyl group having from 1 to 6 carbon atoms, has a main reactor unit (1), at least one metering unit (2, 3, 4) for liquids and/or suspensions, located upstream of the main reactor, and at least one metering unit (5) for gaseous and/or vaporous substances, and also a product workup unit (6) located downstream of the main reactor. A process for preparing substantially halogen-free trialkoxysilanes of the general formula I in which silicon is reacted with alcohols in an inert solvent utilizes at least one organocopper compound catalyst.

Abstract: An apparatus for continuously preparing substantially halogen-free, in particular chlorine-free, trialkoxysilanes of the general formula I

Abstract: The invention concerns solutions of alkoxides containing titanium and/or zirconium and/or hafnium and magnesium and/or calcium and/or strontium and/or barium of general formula (I): [MII(OR)2-y(OR1)y]n.[MIV(OR1)4-z(OR)2], in which: MII means magnesium and/or calcium and/or strontium and/or barium; MIV titanium and/or zirconium and/or hafnium; R is an alkyl group with 1 to 18 carbon atoms; R1 is an alkyl group with 1 to 18 carbon atoms, y has a value of between 0 to 2; z has a value of 0 and 4; and n is a number between 0.001 and 3, with the exception that n cannot be 1 when y is 2 and z is 0, or when y is 0 and z is 4. The invention further concerns the production of these alkoxides and their use.

Abstract: Disclosed are very pure zirconium and hafnium orthoesters and a method for their preparation. In this method the reaction between the halides of these metals and the alcohols is performed in the presence of hydrocarbons or chlorinated hydrocarbons, and the alcohol is not use in excess. The obtained orthoesters are in very pure form and not as addition products with alcohol. They can be isolated as solids.

Abstract: Disclosed is a new method for the preparation of metallic acid esters of titanium, zirconium or hafnium wherein a halide of the metal reacts with an organosilane ester, resulting in the formation of partial esters of the metallic acids. The degree of esterification of the metallic acid ester can be controlled based on the organosilane ester and it is possible to obtain complete esterification of the metal halides. The metallic acid partial esters prepared by the method are very pure, and can be separated selectively from the mixture in a simple manner. The metallic acid alkyl esters obtained can very easily be further esterified to the metallic acid tetraalkyl esters with the formation of very pure tetraalkyl esters.

Abstract: The present invention relates to the esterification of the halides of titanium, zirconium or hafnium. The esterification takes place in two steps. The first step is performed in the absence of acid acceptors, and the alcohol is introduced into the metal halide dissolved in a solvent, without any appreciable contact with the gas phase. The reactor must be held at the boiling temperature. In this step at least half of the alcohol needed for the entire reaction is used. The second esterification step is performed in a known manner with the addition of acid acceptors after the hydrogen halide that formed in the first esterification step has been removed.

Abstract: A method for the continuous or batch preparation of trialkyl organo-oxysilanes by reaction of organic hydroxy compounds with trialkyl halogen silanes in the absence of acid-binding substances is disclosed. The organic hydroxy compound is added directly to the trialkoxy halogen silane in an amount which corresponds to no more than the stoichiometrically necessary amount. The trialkyl halogen silane, or the resultant mixture is always at the boiling temperature or above the boiling temperature in the gaseous state. The reaction mixture is subjected, no later than toward the end of the reaction, to a column distillation in which the column temperature is held such that the reaction is carried to the end within the column. In continuous operation, the trialkyl halogen silane is introduced in gaseous form into the bottom of a column and either kept under reflux or introduced into a reactor into which corresponding stoichiometric amounts of organic hydroxy compound are simultaneously introduced.