17622-94-5Relevant articles and documents
Avoiding carbothermal reduction: Distillation of alkoxysilanes from biogenic, green, and sustainable sources
Laine, Richard M.,Furgal, Joseph C.,Doan, Phi,Pan, David,Popova, Vera,Zhang, Xingwen
supporting information, p. 1065 - 1069 (2016/01/20)
The direct depolymerization of SiO2 to distillable alkoxysilanes has been explored repeatedly without success for 85 years as an alternative to carbothermal reduction (1900 °C) to Simet, followed by treatment with ROH. We report herein the base-catalyzed depolymerization of SiO2 with diols to form distillable spirocyclic alkoxysilanes and Si(OEt)4. Thus, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, or ethylene glycol (EGH2) react with silica sources, such as rice hull ash, in the presence of NaOH (10 %) to form H2O and distillable spirocyclic alkoxysilanes [bis(2-methyl-2,4-pentanediolato) silicate, bis(2,2,4-trimethyl-1,3-pentanediolato) silicate or Si(eg)2 polymer with 5-98 % conversion, as governed by surface area/crystallinity. Si(eg)2 or bis(2-methyl-2,4-pentanediolato) silicate reacted with EtOH and catalytic acid to give Si(OEt)4 in 60 % yield, thus providing inexpensive routes to high-purity precipitated or fumed silica and compounds with single Si-C bonds. No detours: The base-catalyzed depolymerization of SiO2 from different sources with diols led directly to distillable alkoxysilanes, including spirocyclic compounds, thus providing inexpensive routes to high-purity silica and compounds with single Si-C bonds (see scheme): The alkoxysilanes could be converted either into Si(OEt)4 by treatment with EtOH and a catalytic amount of acid or into high-purity precipitated (ppt) or fumed silica.
WATER-SOLUBLE METAL ALCOHOLATE DERIVATIVE, PROCESS FOR PRODUCTION OF THE DERIVATIVE, AND SOLID GELATINOUS AGENT FOR EXTERNAL APPLICATION COMPRISING THE DERIVATIVE
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Page/Page column 9, (2008/12/06)
The object of the present invention is to provide a production method of water-soluble silane derivatives, the separation and purification of which are easy, and the reaction for which can be conducted under an industrially practicable temperature condition (under the temperature condition of 90 °C or lower) and to provide compounds with which solid gelatinous external preparations, with excellent stability against a temperature change and against an effect of additives and with excellent usability, can be prepared. The water-soluble silane derivative could be formed by the substitution reaction of a metal alkoxide with a polyhydric alcohol under the presence of a solid catalyst. According to this production method, the separation of the catalyst from the product is very easy, and the reaction can be carried out under the temperature condition of 90 ° C or lower. The obtained water-soluble metal alcoholate derivative can satisfactory solidify an aqueous formulation of an external preparation by its blending thereinto. The obtained solid gelatinous external preparation has excellent stability against a temperature change and against the effect of additives. In addition, the external preparation is easily disintegrated during use; thus the usability such as easiness to be scooped up with fingers and spreadability during application is excellent.
