US4282162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovery of fluorinated emulsifying acids from basic anion exchangers
Assignee: Hoechst AG
•
Filing: 1980-01-28
•
Granted: 1981-08-04
•
Expires: 2000-01-28
Abstract
Abstract To elute fluorinated emulsifying acids, especially perfluoro-carboxylic acids, from basic anion exchangers a mixture of dilute mineral acid and polar organic solvents is used. The solvent should be miscible with water preferably to an extent of at least 40%. By this process the required amount of eluent and the time of elution can be reduced while simultaneously the amount of recovered emulsifying acid can be improved. The process is especially suitable for the recovery of fluorinated emulsifiers in the coagulation or concentration of fluoropolymer latices.
Inventors
- 👤 Jurgen Kuhls
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:34
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/14; C08F6/16; B; B01; B01J; B01J47/00; B01J47/014; B01J49/00; B01J49/05; B01J49/07; C07; C07C; C07C51/00; C07C51/42; C07C51/47
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
35 words
Process for eluting fluorinated emulsifying acids adsorbed on basic anion exchangers, which comprises eluting the adsorbed fluorinated emulsifying acid from the anion exchanger with a mixture of a dilute mineral acid and an organic solvent.
Claim 2
Dependent Claim
35 words
Process for eluting fluorinated emulsifying acids adsorbed on basic anion exchangers, which comprises eluting the adsorbed fluorinated emulsifying acid from the anion exchanger with a mixture of a dilute mineral acid and an organic solvent.
Claim 3
Dependent Claim
39 words
The process of claim 1, wherein 0.5 to 10 N mineral acid is used in admixture with an organic solvent and the proportion of aqueous mineral acid to organic solvent is in the range of from 1:0.25 to 1:20.
Claim 4
Dependent Claim
39 words
The process of claims 1 and 2, wherein the fluorinated emulsifying acid to be eluted is a perfluorocarboxylic acid of the formula CF 3 (CF 2 ) n COOH in which n is a number from 3 to 10.
Claim 5
Dependent Claim
16 words
The process of claims 1 to 3, wherein hydrochloric acid is used as dilute mineral acid.
Claim 6
Dependent Claim
24 words
The process of claims 1 to 4, wherein the organic solvent is miscible with water to an extent of at least 40% by volume.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-03 | 1985-02-02 | 1985-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-03 | 1989-02-02 | 1989-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-03 | 1993-02-02 | 1993-08-04 | $7700.00 | Window Closed / Lapsed |