Silicone diffusion pump fluids
AssigneeGeneral Electric Company
InventorEdgar D. Brown, Jr.
Life of this patent
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Abstract
The present invention relates to a variety of silicone diffusion pump fluids which are inexpensive to produce. An example of a preferred diffusion pump fluid of the present case is one of the formula, ##STR1## where .phi. is phenyl and such that the fluid boils at 245.degree. C. at 1.5 mm. of Hg pressure. The present invention also has within its scope a process for producing such silicone diffusion pump fluids by hydrolyzing the appropriate chlorosilanes by a reverse hydrolysis procedure, that is, adding the appropriate amount of water to the mixture of chlorosilanes.
Claims12
A process for forming inexpensive silicone diffusion pump fluids capable of maintaining a vacuum of 1.times.10.sup.-6 in a vacuum pump comprising (1) reacting sufficient amounts of an aliphatic alcohol having 1 to 3 carbon atoms with phenyltrichlorosilane so as to substitute on the average from 30% to 80% of the chlorine groups in said silane with alkoxy groups so as to produce an alkoxylated phenylchlorosilane at a temperature of -8 to 25.degree. C.;
- (2) adding at least the stoichiometric amount of water to the mixture of said alkoxylated phenylchlorosilane, trimethylchlorosilane and a phenyl compound selected from the class consisting of diphenyldichlorosilane and diphenylsilane diol to form a mixture of diffusion pump fluids which are phenylsiloxane fluids, and (3) separating all the different fluids by fractional distillation.
A process for forming inexpensive silicone diffusion pump fluids capable of maintaining a vacuum of 1.times.10.sup.-6 mm Hg pressure at 25.degree. C. in a vacuum pump comprising;
- (1) reacting sufficient amounts of ethanol with phenyltrichlorosilane so as to substitute on the average from 60% to 70% of the chlorine groups in said silane with alkoxy groups so as to produce an alkoxylated phenylchlorosilane at a temperature of -8 to 25.degree. C.;
- (2) adding at least the stoichiometric amount of water to the mixture of said alkoxylated phenylchlorosilane, trimethylchlorosilane and a phenyl compound selected from the class consisting of diphenyldichlorosilane and diphenylsilane diol to form a mixture of diffusion pump fluids which are phenylsiloxane fluids, and
- (3) separating all the different fluids by fractional distillation.
Dependencies are inferred from the claim text.