- Determination of Reactive Components in Silicone Foams
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Analytical methods have been developed for the determination of reactive components used in the formulation of room temperature vulcanized (RTV) sislicone foams.The reactive components include total silanol (SiOH), silane hydrogen (SiH), tetrapropoxysilane (TPS), and diphenylmethylsilanol (DPMS).Total SiOH and SiH are determined by Fourier transform infrared (FTIR) spectrometry. the SiOH peak at 3687 cm-1 and the SIH peak at 2168 cm-1 were used for quantitation.The TPS content was determined by gas chromatography (GC), using a solid capillary open tubular (SCOT) column and linear programmed temperature control.The DPMS content was determined by gel permeation chromatography (GPC) using THF solvent.
- Dubiel, S. V.,Griffith, G. W.,Long, C. L.,Baker, G. K.,Smith, Robert E.
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- Method for removing methyldichlorosilane and silicon tetrachloride impurities in trimethyl chlorosilane
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The invention relates to a method for removing methyldichlorosilane and silicon tetrachloride impurities in trimethyl chlorosilane, which comprises a hydrosilylation reaction, a partial esterification reaction and a complete esterification reaction. Firstly, a mixture of trimethylsilyl chloride containing methyldichlorosilane and silicon tetrachloride impurities is added to a reactor for hydrosilylation reaction, and the reaction product enters a separation system. The silicon tetrachloride in the mixture is partially esterified and reacted by adding the low-carbon alcohol as an esterifying agent, and the reaction product enters a separation system. Finally, the partially esterified product is further fully esterified to valuable tetraalkoxy silicon products. The high-efficiency recycling of trimethylchlorosilane is realized, and high-value utilization is also realized.
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Paragraph 0054-0066; 0073-0074; 0078
(2021/08/25)
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- METHOD FOR PRODUCING TETRAALKOXYSILANE
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An object of the present invention is to provide a method capable of producing a tetraalkoxysilane with a high energy efficiency and with a high yield. The present invention provides a method for producing a tetraalkoxysilane, the method including: a first step of reacting an alcohol with a silicon oxide; and a second step of bringing a vaporized component of the reaction mixture obtained in the first step into contact with a molecular sieve.
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Paragraph 0055; 0068; 0073
(2020/12/01)
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- Reaction of silicon with alcohols in autoclave
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A reaction of activated silicon with alcohols in an autoclave at 240—270 °C was studied. It was found that primary alcohols form tetraalkoxysilanes Si(OR)4 with high selectivity (up to 97%), while the secondary PriOH gave a mixture of compounds HSi(OPri)3, Si(OPri)4, HSi(OPri)2OSi(OPri)2H, HSi(OPri)2OSi(OPri)3, and Si(OPri)3OSi(OPri)3 with the predominance of trialkoxysilane (up to 67%). Carrying out the reaction under the indicated conditions has the advantage of experimental simplicity, reagent availability, high conversion of silicon, good isolated yields of products.
- Krylova,Egorov,Nefedov
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p. 260 - 266
(2017/07/11)
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- Direct synthesis of tetraalkoxysilanes from silica and alcohols
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A new simple and efficient process for synthesizing tetraalkoxysilanes (TROS) directly from silica and alcohols was developed using molecular sieves as dehydrating agents. Using this method, a variety of TROS (R = ethoxy, n-propoxy, or n-butoxy) were obtained over 70% yields within 6 h. We also employed various natural silica sources in this process for practical applications.
- Fukaya, Norihisa,Choi, Seong Jib,Horikoshi, Toshio,Kataoka, Sho,Endo, Akira,Kumai, Hiroshi,Hasegawa, Minoru,Sato, Kazuhiko,Choi, Jun-Chul
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supporting information
p. 2224 - 2226
(2017/03/21)
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- COSMETIC TREATMENT METHOD COMPRISING THE APPLICATION OF A COATING BASED ON AN AEROGEL COMPOSITION OF LOW BULK DENSITY
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The present invention relates to a cosmetic treatment method comprising the formation of a coating on keratin fibres characterized in that it comprises: 1) the preparation of an aerogel precursor composition comprising:—at least one organic solvent chosen from acetone, C1-C4 alcohols, C1-C6 alkanes, C1-C4 ethers, which may or may not be perfluorinated, and mixtures thereof and at least one precursor compound that contains:—at least one atom chosen from silicon, titanium, aluminium and zirconium,—at least one hydroxyl or alkoxy function directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by an oxygen atom, and,—optionally an organic group directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by a carbon atom, 2) the removal of the solvent or solvents resulting in the formation of an aerogel composition having a bulk density less than or equal to 0.35 g/cm3, 3) the application to the keratin fibres of the aerogel composition resulting from step 2) or of the aerogel precursor composition resulting from step 1). Advantageously, the molar ratio between the precursor compounds and the solvent is at most 1/20.
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Paragraph 0067
(2014/02/15)
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- Process for preparing low-chloride or chloride-free alkoxysilanes
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A process for preparing an alkoxysilane with an acidic chloride content of less than 10 ppm by weight, comprising: reacting a chlorosilane with an alcohol in a water-free and solvent-free phase to form a product mixture containing alkoxysilane and residual acidic chloride, with removal of resultant hydrogen chloride from the product mixture, then adding liquid or gaseous ammonia, in an amount corresponding to a stoichiometric excess, based on the content of acidic chloride, to form an ammonia-containing product mixture, treating the ammonia-containing product mixture at a temperature between 10 and 50 DEG C., wherein the ammonia and acidic chloride undergo neutralization, to form a crude product, and optionally, then separating off a salt formed in the course of neutralization, from the crude product, and recovering the alkoxysilane by distilling the crude product.
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