Reactive distillation of chlorosilanes
AssigneeDow Corning Corporation
InventorsAndrew Bruce Gammie, Christopher Darren Gatti, Roland Lee Halm, Christopher James Kozenski, Dennis Gene Van Koevering
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Abstract
Chlorosilanes such as dimethyldichlorosilane are hydrolyzed in a first super-azeotropic hydrochloric acid distillation column A to produce cyclosiloxanes, chlorosiloxanes, and hydrogen chloride gas. The cyclosiloxanes and the chlorosiloxanes are washed and separated according to their volatility in a second sub-azeotropic hydrochloric acid distillation column B, to produce a substantially chloride free volatile cyclosiloxane stream and a substantially chloride free non-volatile siloxane stream. The process is substantially chloride efficient.
Claims17
A method of hydrolyzing chlorosilanes comprising:
- (i) feeding one or more chlorosilanes to a first super-azeotropic hydrochloric acid distillation column, and removing cyclosiloxanes and linear chlorosiloxanes from the first column;
- (ii) feeding substantially chloride free water to a second sub-azeotropic hydrochloric acid distillation column;
- (iii) removing HCl gas from the upper portion of the first column;
- (iv) removing saturated aqueous HCl from the lower portion of the first column and recirculating it to the upper portion of the first column;
- (v) feeding cyclosiloxanes and linear chlorosiloxanes from the first column to the second column;
- (vi) removing substantially chloride free cyclosiloxanes from the upper portion of the second column and non-volatile substantially chloride free siloxanes from a lower portion of the second column;
- and
- (vii) removing aqueous HCl from the lower portion of the second column and recirculating it to the first column.
Dependencies are inferred from the claim text.