Patent GB-611425-A (GB)
Title: Improved method of preparing organo-silicon esters
IPC: C07F7/02
Filed: 1946-04-23
Abstract: The surfaces of metals or wood are modified and rendered water repellent by applying thereto an organo silicon ester of the general formula <FORM:0611425/III/1> where R represents the same or different hydrocarbon or hydrocarbonoxy radicals at least one of which is an alkyl or alkoxy radical containing 8 or more carbon atoms, R1 represents hydrogen or a hydrocarbon radical and n is an integer not greater than 3, followed by heating.  Specific compounds mentioned are tridodecoxy silicon formate, tridodecoxy silicon acetate, trioctadecoxy silicon acetate, dioctadecoxy-propoxy-silicon acetate, octadecoxy-dodecoxy-propoxy-silicon acetate, didodecoxy-silicon diacetate, dodecoxy silicon triacetate, trimyricyloxy silicon acetate, trioctyloxy silicon acetate, didodecoxy-iso-amyl silicon acetate, dodecoxy-diphenyl silicon acetate, tridodecyl-silicon acetate, dodecyl diphenyl silicon acetate, dodecoxy - dioctyloxy silicon stearate and dodecyl silicon triacetate.ALSO:Organo-silicon esters of the general formula <FORM:0611425/IV(a)/1> where R represents the same or different hydrocarbon or hydrocarbonoxy radicals at least one of which is an alkyl or alkoxy radical containing 8 or more carbon atoms, R1 represents hydrogen or a hydrocarbon radical and n is an integer not greater than 3, are hydrolysed to form organo-silicols which can undergo condensation reactions to form viscous liquid or solid products.ALSO:Organo-silicon esters of the general formula <FORM:0611425/IV(b)/1> where R represents the same or different hydrocarbon or hydrocarbonoxy radicals at least one of which is an alkyl or alkoxy radical containing 8 or more carbon atoms, R1 represents hydrogen or a hydrocarbon radical and n is an integer not greater than 3, are prepared by reacting the corresponding organo silicon halide with a carboxylic acid or a salt thereof, the proportion of the latter being equivalent to or in excess of the equivalent of the halogen atoms of the organo silicon halide, at an elevated temperature, and the reaction may be effected in the presence of an inert organic solvent, e.g. petroleum ether, ligroin, benzene or toluene.  Suitable organo-silicon halides are octyl-silicon trichloride, decyl-silicon trichloride, di-octyl-silicon dichloride, tridodecyl-silicon chloride, di-myricyl-silicon dichloride, octyloxy-silicon trichloride, di-octyloxy-silicon dichloride, trioctyloxy-silicon chloride, dodecoxy-silicon trichloride, phenyl-octyl-dodecoxy-silicon chloride, di - dodecyl - dodecoxy - silicon chloride, and dodecyl-myricyloxy-silicon chloride, and the corresponding bromides. Suitable salts of organic carboxylic acids are sodium formate, potassium acetate, sodium propionate, potassium butyrate, the sodium salts of valeric, crotonic, oleic, stearic, benzoic and cinnamic acids, and salts of polycarboxylic acids. The organo-silicon esters may be hydrolysed to form organo-silicols which can undergo condensation reactions to form viscous liquid or solid products, or they may be reacted with hydroxy compounds, e.g. alcohols, phenols or cellulose to form corresponding alkoxy - silicon derivatives.  In example (1), the following organo-silicon esters are prepared: tridodecoxy silicon formate, tridodecoxy silicon acetate, trioctadecoxy silicon acetate, dioctadecoxy-propoxy-silicon acetate, octadecoxy-dodecoxy-propoxysilicon acetate, didodecoxy silicon diacetate, dodecoxy silicon triacetate, trimyricyloxy-silicon acetate, trioctyloxy silicon acetate, didodecoxy-iso-amyl silicon acetate, dodecoxy-di-phenyl silicon acetate, tridodecyl silicon acetate, dodecyl - di - phenyl silicon acetate, dodecoxy-di-octyloxy silicon stearate and a mixture of dodecyl silicon triacetate and C12H25SiO3CCH3.  Organo-silicon halides for the process of the invention are prepared by reacting a silicon tetrahalide with an alkyl magnesium halide.  Alkoxy silicon halides suitable for the process of the invention are prepared by reacting an alcohol with a polyhalo-silicon compound, e.g. silicon tetrachloride or bromide, diethyl-silicon dichloride or phenyl-silicon trichloride.