A transesterification process for preparing alkoxysilane includes removal of metal transesterification catalyst from the alkoxysilane transesterification reaction medium.

A process for preparing an acryloyloxysilane, comprising: reacting a metal salt of a carboxylic acid having the formula
[CR.sup.2.sub.2CR.sup.1CO.sup.].sub.aM.sup.a+(I),
with a haloorganoalkoxysilane having the formula
XR.sup.3Si(OR.sup.4).sub.nR.sup.5.sub.3-n(II)
at a temperature of from 50 to 160 C. and in the presence of a catalyst, and in the presence of water, an alcohol comprising 1 to 5 carbon atoms, or a combination of water and an alcohol comprising 1 to 5 carbon atoms, to form a mixture comprising an acryloyloxysilane and a metal halide having the formula
M.sup.a+X.sup..sub.a(III),
wherein R.sup.1 is H, R.sup.7COO.sup.M.sup.a+, or C.sub.1-C.sub.6 hydrocarbyl, each R.sup.2 is independently R.sup.1 or [COO.sup.]M.sup.a+, M.sup.a+ is an alkali metal cation or alkaline earth metal cation, a is 1 or 2, X is halo, R.sup.3 is C.sub.1-C.sub.6 hydrocarbylene, each R.sup.4 is independently C.sub.1-C.sub.10 hydrocarbyl, each R.sup.5 is independently R.sup.1 and n is an integer from 1 to 3.

A process for preparing an acryloyloxysilane, comprising: reacting a metal salt of a carboxylic acid having the formula
[CR.sup.2.sub.2CR.sup.1CO.sup.].sub.aM.sup.a+(I),
with a haloorganoalkoxysilane having the formula
XR.sup.3Si(OR.sup.4).sub.nR.sup.5.sub.3-n(II)
at a temperature of from 50 to 160 C. and in the presence of a catalyst, and in the presence of water, an alcohol comprising 1 to 5 carbon atoms, or a combination of water and an alcohol comprising 1 to 5 carbon atoms, to form a mixture comprising an acryloyloxysilane and a metal halide having the formula
M.sup.a+X.sup..sub.a(III),
wherein R.sup.1 is H, R.sup.7COO.sup.M.sup.a+, or C.sub.1-C.sub.6 hydrocarbyl, each R.sup.2 is independently R.sup.1 or [COO.sup.]M.sup.a+, M.sup.a+ is an alkali metal cation or alkaline earth metal cation, a is 1 or 2, X is halo, R.sup.3 is C.sub.1-C.sub.6 hydrocarbylene, each R.sup.4 is independently C.sub.1-C.sub.10 hydrocarbyl, each R.sup.5 is independently R.sup.1 and n is an integer from 1 to 3.

A process can prepare a colourless, methanolic solution of 3-(N-benzyl-2-aminoethyl)aminopropyltrimethoxysilane hydrochloride. The process includes, in step 1 fractionally distilling the vinylbenzyl chloride reactant component with addition of at least one stabilizer, and in step 2, metering and mixing the distillate (vinylbenzyl chloride) from step 1 into an initial charge of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and methanol in a molar ratio of the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to vinylbenzyl chloride of 1.0:0.80 to 1.0:1.15 and at a temperature in the range from 40 to 60 C. and leaving them to react further. The colourless, methanolic solution has an APHA colour number of <200 mg PtCo/I.

A process can prepare a colourless, methanolic solution of 3-(N-benzyl-2-aminoethyl)aminopropyltrimethoxysilane hydrochloride. The process includes, in step 1 fractionally distilling the vinylbenzyl chloride reactant component with addition of at least one stabilizer, and in step 2, metering and mixing the distillate (vinylbenzyl chloride) from step 1 into an initial charge of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and methanol in a molar ratio of the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to vinylbenzyl chloride of 1.0:0.80 to 1.0:1.15 and at a temperature in the range from 40 to 60 C. and leaving them to react further. The colourless, methanolic solution has an APHA colour number of <200 mg PtCo/I.

A process for purifying an acryloyloxysilane comprising subjecting a mixture comprising an acryloyloxysilane, a haloorganoalkoxysilane, and an alkane-based non-polar solvent to a temperature and pressure sufficient to vaporize a portion of the non-polar solvent, the haloorganoalkoxysilane, or the non-polar solvent and the haloorganoalkoxysilane from the mixture to produce a purified mixture comprising the acryloyloxysilane. The examples disclose a three-step short-path distillation process, where in the first two passes, the residue-fraction is the one containing the product, whereas in the third path, the distillate is containing the purified product.

A process for purifying an acryloyloxysilane comprising subjecting a mixture comprising an acryloyloxysilane, a haloorganoalkoxysilane, and an alkane-based non-polar solvent to a temperature and pressure sufficient to vaporize a portion of the non-polar solvent, the haloorganoalkoxysilane, or the non-polar solvent and the haloorganoalkoxysilane from the mixture to produce a purified mixture comprising the acryloyloxysilane. The examples disclose a three-step short-path distillation process, where in the first two passes, the residue-fraction is the one containing the product, whereas in the third path, the distillate is containing the purified product.

A reversible photo-switchable isomerization of novel sterically hindered 2,2,6,6-tetramethyl-4,4-bis((trimethylsilyl)ethynyl)azobenzene and its synthesis.

A reversible photo-switchable isomerization of novel sterically hindered 2,2,6,6-tetramethyl-4,4-bis((trimethylsilyl)ethynyl)azobenzene and its synthesis.

Organosilicon compounds in a process exhaust stream from silicone production are removed by contacting the exhaust stream with a semipermeable silicone membrane which is selectively permeable to organosilicon compounds and oxygen relative to nitrogen. The pressure on the permeate side of the membrane is preferably less than the pressure on the retentate side.