Toray Silicone Company Limited

Ikuzo Takahashi

Takeshi Imai

Shuzo Toida

Masahiko Suzuki

Junpei Sugihara

A method for purifying impure hexamethyldisiloxane comprising as a major portion hexamethyldisiloxane and as a minor portion a mixture of low-boiling organic solvents, other organosilicon compounds, and odor-producing materials is described. The method comprises (A) first, treating the impure hexamethyldisiloxane with a condensation catalyst to convert the organosilicon compounds to additional hexamethyldisiloxane; (B) second, washing the treated impure hexamethyldisiloxane with water; (C) third, separating a water phase from the washed impure hexamethyldisiloxane; (D) fourth, distilling the washed impure hexamethyldisiloxane to yield hexamethyldisiloxane of enhanced purity; (E) fifth, contacting the hexamethyldisiloxane of enhanced purity with acid clay at a temperature of greater than about 50.degree. C.; and (F) finally, contacting the acid clay treated hexamethyldisiloxane of enhanced purity treated in (E) with activated carbon to yield hexamethyldisiloxane with enhanced purity and minimal unpleasant odor.

Method for purifying hexamethyldisiloxane

A method for purifying alkoxysilane with the general formula, R.sub.m Si(OR.sup.1).sub.4-m. The method significantly lowers the level of non-hydrolyzable chlorine-based impurities, as well as the level of hydrolyzable chlorine-based impurities. The method comprises: (i) heating the alkoxysilane in the presence of a treating agent selected from a group which consists of acid clays and metal halides; (ii) contacting the alkoxysilane with a neutralization agent; and (iii) separating the alkoxysilane from the unused neutralization agent and by-products of neutralization.

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Chiba, Japan

Ikuzo Takahashi