GB657169A - Alkylsilsesquioxanes - Google Patents

Abstract

Soluble, completely condensed alkylsilsesquioxanes, having the formula (R.SiO1,5)n, where R is an alkyl radical containing 2 to 6 carbon atoms and n is an integer from 8 to 24, are made by destructive distillation of an alkylsilsesquioxane hydrolysate (i.e. the hydrolysis product of a silane having the formula R.SiX3, where R is an alkyl radical containing 2 to 6 carbon atoms and X is a readily hydrolysable group such as alkoxy or halogen atom), or by distillation above 200 DEG C., but preferably below 500 DEG C., and at a pressure below 5 mm. of a mixture of an alkali metal hydroxide and either the hydrolysis product of an alkyltrichlorosilane or an incompletely condensed alkylsilsesquioxane polymer, in which the alkyl radical contains 2 to 6 carbon atoms. The products may be separated into their components by fractional distillation or by crystallization. In examples: (1) C3H5SiC13; (2) C2H7SiC13 and (3) n-C4H9SiC13 were hydrolysed and the resulting oily-products mixed with powdered NaOH and distilled under reduced pressure to give paste-like products from which were separated by crystallization from acetone (C3H7SiO1,5)8, (C2H5SiO1,5)8 and (C4H9SiO1,5)8, respectively, the p uncrystallized material remaining in each case being a viscous oil; (4) distillation of NaOH and the hydrolysis product of C6H13SiC13 gave a mixture of polymers containing an average of 14.8 units of the formula (C6H13SiO1,5). The liquid compounds may be employed as lubricants and damping fluids. When heated to above 150 DEG C. with or without catalysts such as alkali metal hydroxide or alcoholate and organo metallic salts such as lead naphthenate, they form insoluble resinous compounds, and consequently find use in coatings, adhesives and potting compounds.