Evonik Degussa Gmbh

Evonik Operations Gmbh

Stefan Bade

Norbert Schladerbeck

Susann Witzsche

Markus Rudek

Burkhard Standke

Uwe Numrich

Jörg Sauer

Torsten Peterle

Matthias Koebel

Wim Malfait

Reiner Störger

Burkhard John

Claudia Drescher

Andre Nehls

Beate Seliger

Joerg Sauer

Nicolas Marion

Nicolas Vogel

Stefanie Hauser

The present invention relates to a process for producing a hydrophobized silica aerogel, comprising the following steps: a) preparing a hydrophobized silica gel comprising alkoxy groups; b) drying of the hydrophobized silica gel obtained in step a); c) treatment of the product obtained in step b) with a gas mixture comprising water and a base or an acid. A hydrophobized silica aerogel with a reduced alkoxy group content, suitable for thermal insulation applications, is also provided.

Silica aerogel with increased alkaline stability

Novel epoxy-functional alkoxysilanes have, for example, formulae II, III, IV, V, and VI. 

Epoxy-functional alkoxysilanes, method for the production and use thereof

A process can prepare a 3-glycidyloxypropylalkoxysilane of formula (I), (R')O&#x2014;(CH)&#x2014;Si(OR)(I), where R groups are independently a methyl or ethyl group and R&#x2032; represents an HC(O)CHCH&#x2014; group. The process includes reacting (i) a functionalized alkene of formula (II), (R&#x2032;)O&#x2014;CH(II), where R&#x2032; represents an HC(O)CHCH&#x2014; group, with (ii) at least one hydroalkoxysilane of formula (III), HSi(OR)(III), where R groups are independently a methyl or ethyl group. The reacting takes place in the presence of (iii) a Karstedt catalyst or a catalyst having hexachloroplatinic acid as a homogeneous catalyst, and (iv) 2-ethylhexanoic acid, isononanoic acid, or both. The process further includes obtaining a product of the reacting.

Process for preparing 3-glycidyloxypropyltrialkoxysilanes

Described is a method for producing alkenyl halosilanes by reacting alkenyl halide selected from the group comprising vinyl halide, vinylidene halide, and allyl halide with halosilane selected from the group comprising monohalosilane, dihalosilane, and trihalosilane in the gas phase in a reactor comprising a reaction tube () that has an inlet () at one end and an outlet () at the other end, said reactor further comprising an annular-gap nozzle () that is mounted on the inlet (), extends into the reaction tube (), and has a central supply duct () for one reactant () and a supply duct (), which surrounds the central supply duct (), for the other reactant (). In order to carry out said method, alkenyl halide is injected into the reaction tube () through the central supply duct (), halosilane is injected thereinto through the surrounding supply duct (), and both substances flow through the reaction tube () in the direction of the outlet (). The described method allows alkenyl halosilanes to be produced at a high yield and with great selectivity. The amount of soot formed is significantly lower than in conventional reactors. The invention also relates to a reactor for carrying out gas-phase reactions, said reactor being characterized by at least the following elements: A) a reaction tube () that has B) an inlet () at one end, C) an outlet () at the other end, and D) an annular-gap nozzle () which includes a central supply duct () for one reactant () and a supply duct (), which surrounds the central supply duct (), for another reactant (), said nozzle being mounted on the inlet () and extending into the reaction tube ().

Process for preparing alkenylhalosilanes and reactor suitable therefor

What is described is a process for continuously esterifying halosilanes of the formula I with alcohols of the formula II to give silane esters of the formula III in a single column ()RSiHal&#x2003;&#x2003;(I)R&#x2014;(OH)&#x2003;&#x2003;(II)RS&#x2014;(OR)&#x2003;&#x2003;(III) The invention also relates to a column () for continuously esterifying halosilanes of the above-described formula I with alcohols of the formula II to give silane esters of the formula III, comprising the following elements: The process described allows the preparation of silane esters of the formula III with high selectivity.

Process for esterifying silicon-halogen compounds in a column and apparatus suitable therefor

A process for preparing alkenylhalosilanes by reacting alkenyl halide in the gas phase in a reactor comprising a reaction tube () equipped with an inlet () at one end of the tube and with an outlet () at the other end of the tube, and having a gas inlet device () having a plurality of gas feed points () that are spaced apart in the direction of the longitudinal axis of the reaction tube () and open into the reaction tube (). The process permits the preparation of alkenylhalosilanes in high yield and with high selectivity. The formation of soot is distinctly lower compared to conventional reactors.

Process for preparing alkenylhalosilanes and reactor suitable therefore

The present invention relates to a process for preparing glycidyloxy-alkylalkoxysilanes of the general formula (I) (R&#x2033;)O&#x2014;CHSi(R')(OR)(I) in which R and R&#x2032; groups are each independently linear or branched alkyl groups having from 1 to 4 carbon atoms, n is 1, 2, 3, 4, 5, 6, 7 or 8 and m is 0, 1, 2 or 3, and R&#x2033; is an HC(O)CH&#x2014; or HC(O)CHCH&#x2014; group, by reacting (i) a functionalized alkene of the general formula (II) (R&#x2033;)O&#x2014;CH(II) in which R&#x2033; is an HC(O)CH&#x2014; or HC(O)CHCH&#x2014; group and n is 1, 2, 3, 4, 5, 6, 7 or 8 with (ii) at least one hydroalkoxy-silane of the general formula (III) HSi(R&#x2032;)(OR)(III) in which R and R&#x2032; groups are each independently linear or branched alkyl groups having from 1 to 4 carbon atoms and m is 0, 1, 2 or 3, in the presence (iii) of at least one homogeneous catalyst, (iv) of at least one solvent and/or of a diluent and (v) of at least one promoter.

Process for preparing glycidyloxyalkyltrialkoxysilanes

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Michelbach le Haut, France

Stefan Bade