GB648406A - Process for making organo-silicon compounds - Google Patents

Abstract

Alkoxy silanes of the general formula RySi(OR1)4-y, where R and R1 are alkyl or aromatic hydrocarbon radicals and y is an integer from 1 to 3, are hydrolyzed by heating them under substantially anhydrous conditions with a paratoluene sulphonic acid, a strong inorganic acid or an acid salt or a halide or an amphoteric metal, to produce a mixture of a silanol and a siloxane and an organic ester. The ester may be distilled or dissolved out of the mixture or may remain to act as a plasticizer for the product. The heating may be sufficient to polymerize the silanol to a siloxane. Fabrics, paper, glass, ceramics may be made water-repellent by treating with the reaction mixture, heating to drive of volatile ester and continuing heating at 150 DEG C. The alkoxysilane may be trimethylmethoxy-, diethyldiethoxy, amyltributoxy, dibenzyldimethoxy, phenyltriethoxy, trimethylphenoxy, triethyl-3-hydroxypyridyloxy-silane. The acid may be aliphatic, e.g. formic, acetic, propionic, oleic, stearic, abietic, adipic; aliphatic-hydroxy, e.g. glycollic, malic, lactic, or dicarboxylic, e.g. maleic, citric, tartaric; or aromatic, e.g. benzoic, salicylic, phthalic. In examples: (1) mono-amyl-triethoxysilane was acidolyzed by formic acid using paratolnenesulphonic acid as catalyst to give a mixture of mono-amyl-silantriol and polyamylsiloxane which, further heated, became solid; (2) mono-amyl triethoxy silane was acidolyzed by the complex of acetic acid-boron fluoride, and (3), (4), (5), (6) by benzoic phthalic, maleic and lactic acids; (4) monoethyl triethoxy silane was refluxed with acetic acid. The Specification as open to inspection under Sect. 91 comprises also an example in which a cotton fabric was impregnated with ammonium bifluoride, immersed in a mixture of p monoamyltriethoxysilane, ethyl silicate and acetic acid, dried and ironed while damp to produce in situ a silanol/siloxane mixture imparting water-repelling properties. It also states that the acidolysis may be carried out by hydrolysis with water, e.g. a mixture of an organo-silicon halide and an organo-alkery silane may be treated first with water to hydrolize the halide and then with the organic acid and catalyst. It also contains a further example (7) which states that one mol. monoethyl triethoxy silane was refluxed with 3 moles acetic acid and 1 mol. HCL. After 2 hours the ethyl acetate was distilled from the reaction mixture yeld of mono-ethyl-silane trial was obtained. This subject-matter does not appear in the Specification as accepted.ALSO:Alkoxy silanes of the general formula RySi(OR1)4-y, where R and R1 are alkyl or aromatic hydrocarbon radicals and y is an integer from 1 to 3 are hydrolysed by heating them under substantially anhydrous conditions with a paratoluene sulphonic acid, a strong inorganic acid or an acid salt or a halide of an amphoteric metal, to produce a mixture of a silanol and a siloxane and an organic ester. The ester may be distilled or dissolved out of the mixture. The alkoxysilane may be trimethylmethoxy-, diethyldiethoxy-, amyltributoxy-, dibenzyldimethoxy-, phenyltriethoxy-, trimethylphenoxy-, or triethyl-3-hydroxypyridyloxy-silane. The acid may be aliphatic, e.g. formic, acetic, propionic, oleic, stearic, abietic, adipic; aliphatic-hydroxy, e.g. glycollic, malic, lactic, or dicarboxylic, e.g. maleic, citric, tartaric; or aromatic, e.g. benzoic, salicylic, phthalic. In examples: (1) mono-amyl-triethoxysilane was acidolyzed by formic acid using paratoluenesulphonic acid as catalyst to give a mixture of mono-amyl-silantriol and polyamylsiloxane; (2) mono-amyl-triethoxysilane was acidolyzed by the complex of acetic acid-boron fluoride and (3), (4), (5), (6) by benzoic, phthalic, maleic and lactic acids to give a product as in (1). The Specification as open to inspection under Sect. 91 comprises also an example (7) which states that one mol. monoethyl triethoxy silane was refluxed with 3 moles acetic acid and 1 mol. HCL. After 2 hours the ethyl acetate was distilled from the reaction mixture and a theoretical yield of mono-ethyl silane triol was obtained. This subject-matter does not appear in the Specification as accepted.