GB746193A - Method of producing organo-silicon polymers - Google Patents

Abstract

Organosilicon polymers, consisting essentially of Si-O-Si units but which may contain Si-H and Si-Si units, are made by hydrolysing organosilanes containing at least one Si-H and/or Si-Si unit with liquid mixtures of alcohol, water and ammonia, and condensing the resulting products if desired by heating. The silanes used contain, in addition to SiH and/or Si-Si units, organic radicals such as alkyl, chloroalkyl and aryl and may also contain hydrolysable radicals such as Cl, OR and OCOR. Alcohols specified are methanol, ethanol, propanol, ethylene glycol and glycerine. In one embodiment water and/or ammonia is added to an alcoholic solution of the silane(s), e.g. ammonia gas, with or without a diluent such as nitrogen, may be passed into an aqueous alcoholic solution of the silane(s), or water may be added to an alcoholic solution of the silane saturated with ammonia gas. Where the silane contains hydrolysable halogen, e.g. chlorine, it is preferred to hydrolyse the chlorine in an acid medium and complete the hydrolysis in an ammoniacal medium. In examples, the product obtained by removal of the hydrolysing medium after hydrolysis by (1) adding aqueous ammonia to a methanol solution of diethylsilane, is a polysiloxane oil; (2) adding (SiCH3)x, a yellow solid obtained by reacting SiH4 with ethylene at 520 DEG C., to propanol and aqueous ammonia, is a white solid methylpolysiloxane; (3) passing ammonia gas into an aqueous 1:6-hexanediol solution of alkylsilanes (containing SiH and Si-Si units) obtained as the oily reaction product of mono-and di-silanes with ethylene at 500 DEG C., is a sticky resin which hardens on heating in air; (4) introducing liquid monoethylsilane (B.P. - 14 DEG C.) into a mixture of methanol, water and ammonia at - 80 DEG C., is an ethylpolysiloxane oil, which can be solidified by oxidation with HgO; (5) pouring an ether solution of (CH3)2SiHCl into ice water and adding ammonia and methanol, is a viscous dimethylpolysiloxane, which can be converted in known manner into silicone rubber. The products may be used in the production of damping oils, pump oils, lubricants, stopcock grease, lacquers, thermal and electrical insulation, heat-resistant packings, corrosion-proof coatings and elastic mouldings.