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US4209470A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the separation of hydrogen fluoride from its mixtures with 1-chloro-1,1-difluoroethane

Assignee: Solvay SA
•
Filing: 1979-01-10
•
Granted: 1980-06-24
•
Expires: 1999-01-10
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Abstract

Abstract Process for the separation of hydrogen fluoride from its mixtures with 1-chloro-1,1-difluoroethane, such as those obtained in the manufacture of the latter. An auxiliary solvent, chosen from among 1,1-dichloro-1-fluoroethane, vinylidene chloride, 1,1,1-trichloroethane and mixtures thereof, is added to the mixture so as to obtain two separate liquid phases, one of which contains the hydrogen fluoride and the other of which contains the 1-chloro-1,1-difluoroethane. Virtually all the hydrogen fluoride is recovered in the anhydrous form in the manufacture of monomers such as vinylidene fluoride, from chlorohydrocarbons such as vinylidene chloride and 1,1,1-trichloroethane.

Inventors

  • 👤 Robert Lorquet

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 09:26
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38; C01; C01B; C01B7/00; C01B7/19; C01B7/191; C01B7/195

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 67 words
Process for the separation of hydrogen fluoride from its liquid mixtures with 1-chloro-1,1-difluoroethane, comprising: separating the liquid mixture by decantation to obtain a liquid organic phase enriched in 1-chloro-1,1-difluoroethane and a liquid organic phase enriched in hydrogen fluoride by adding to the mixture a liquid containing an auxiliary solvent, selected from the group consisting of 1,1-dichloro-1-fluoroethane, vinylidene chloride, 1,1,1-trichloroethane and mixtures thereof, before subjecting it to decantation.
Claim 2
Dependent Claim 67 words
Process for the separation of hydrogen fluoride from its liquid mixtures with 1-chloro-1,1-difluoroethane, comprising: separating the liquid mixture by decantation to obtain a liquid organic phase enriched in 1-chloro-1,1-difluoroethane and a liquid organic phase enriched in hydrogen fluoride by adding to the mixture a liquid containing an auxiliary solvent, selected from the group consisting of 1,1-dichloro-1-fluoroethane, vinylidene chloride, 1,1,1-trichloroethane and mixtures thereof, before subjecting it to decantation.
Claim 3
Dependent Claim 21 words
Process according to claim 1, wherein the liquid added contains less than 50% by weight of 1-chloro-1,1-difluoroethane and of hydrogen fluoride.
Claim 4
Dependent Claim 18 words
Process according to claim 2, wherein the liquid added is formed exclusively of 1,1-dichloro-1-fluoroethane, vinylidene chloride and 1,1,1-trichloroethane.
Claim 5
Dependent Claim 30 words
Process according to claim 1, wherein the liquid added is employed at the rate of about 0.05 to 2.5 mols of 1,1-dichloro-1-fluoroethane, vinylidene chloride and 1,1,1-trichloroethane per mol of 1-chloro-1,1-difluoroethane.
Claim 6
Dependent Claim 17 words
Process according to claim 1, wherein the separation is carried out at a temperature below 110° C.
Claim 7
Dependent Claim 22 words
Process according to claim 1, wherein the separation is carried out at a pressure ranging from 0.8 to 30 kg/cm 2 .
Claim 8
Dependent Claim 20 words
Process according to claim 1, wherein the liquid added is a reaction mixture originating from the hydrofluorination of vinylidene chloride.
Claim 9
Dependent Claim 19 words
Process according to claim 1, wherein the liquid added is a reaction mixture originating from the hydrofluorination of 1,1,1-trichloroethane.
Claim 10
Dependent Claim 29 words
Process according to claim 1, wherein the mixture of hydrogen fluoride and 1-chloro-1,1-difluoroethane subjected to the separation contains at least 80% by weight of hydrogen fluoride and of 1-chloro-1,1-difluoroethane.
Claim 11
Dependent Claim 25 words
Process according to claim 1, wherein the mixture of hydrogen fluoride and 1-chloro-1,1-difluoroethane subjected to the separation has a composition similar to the azeotropic composition.
Claim 12
Dependent Claim 63 words
Process according to claim 1, wherein the separation is carried out in a condenser/decanter in which the top product from two distillations is condensed, to which product the liquid is added and from which the liquid organic phase is withdrawn and fed into the reflux of one distillation and the liquid inorganic phase is withdrawn and fed into the reflux of the other.
Claim 13
Dependent Claim 25 words
Process according to claim 11, wherein the top product has a composition similar to the azeotropic composition of the mixtures of hydrogen fluoride and 1-chloro-1,1-difluoroethane.

References Cited (Backward Citations)

US2894044A Cited
US3442961A Cited
US3696156A Cited
GB1323234A Cited
US3873629A Cited
US4157380A Cited
US4102981A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-06-24 1983-12-24 1984-06-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-06-24 1987-12-24 1988-06-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-06-24 1991-12-24 1992-06-24 $7700.00 Window Closed / Lapsed

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