US3882153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for recovering fluorinated carboxylic acid
Assignee: Kureha Corp
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Filing: 1973-04-04
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Granted: 1975-05-06
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Expires: 1993-04-04
Abstract
Abstract Fluorinated carboxylic acid is efficiently recovered by passing its diluted solution in adsorptive contact with a weak basic anion-exchange resin to cause the fluorinated carboxylic acid contained in the diluted solution to be absorbed onto the anionexchange resin, then eluting the anion-exchange resin with an aqueous ammonia solution to transfer the adsorbed fluorinated carboxylic acid to the eluent.
Inventors
- 👤 Shigeru Seki
- 👤 Koji Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:54
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/47; C08; C08F; C08F6/00; C08F6/14; C08F6/16; C02; C02F; C02F1/00; C02F1/42; C02F2001/422; C02F2101/00; C02F2101/30; C02F2101/36
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A METHOD FOR RECOVERING A FLUORINATED CARBOXYLIC ACID FROM A DILUTE AQUEOUS SOLUTION, WHICH COMPRISES CONTACTING A WEAK BASIC ANION EXCHANGE RESIN WITH A DILUTE AQUEOUS SOLUTION OF A FLUORINATED CARBOXYLIC ACID OF THE FORMULA X-CYZCF2)NCOOM, WHERE X IS H, CL, F, CF3, OR CF2CL; Y IS H OR F; Z IS H, CL, OR F; M IS H, NH4, K OR NA; AND N IS AN INTEGER OF 2 TO 6, AND CONTAINING A TOTAL OF 5-13 CARBON ATOMS IN THE X-CYZ-CF2)N GROUP TO ADSORB THE FLUORINATED CARBOXYLIC ACID ONTO THE BASIC ANION EXCHANGE RESIN, AND THEN CONTACTING THE AMINO EXCHANGE RESIN WITH AN AQUEOUS SOLUTION OF NH3 AS AN ELUENT TO TRANSFER THE FLUORINATED CARBOXYLIC ACID FROM THE ANION EXCHANGE RESIN INTO THE ELUENT TO ISOLATE THE FLUORINATED CARBOXYLIC ACID; AND SAID WEAK BASIC ANION EXCHANGE RESIN (A) CONTAINING AT LEAST ONE AMINE GROUP, AS AN EXCHANGE GROUP SELECTED FROM PRIMARY, SECONDARY AND TERTIARY AMINES, AND (B) HAVING A PH IN THE RANGE OF 0 TO 7.0.
Claim 2
Independent Claim
169 words
A METHOD FOR RECOVERING A FLUORINATED CARBOXYLIC ACID FROM A DILUTE AQUEOUS SOLUTION, WHICH COMPRISES CONTACTING A WEAK BASIC ANION EXCHANGE RESIN WITH A DILUTE AQUEOUS SOLUTION OF A FLUORINATED CARBOXYLIC ACID OF THE FORMULA X-CYZCF2)NCOOM, WHERE X IS H, CL, F, CF3, OR CF2CL; Y IS H OR F; Z IS H, CL, OR F; M IS H, NH4, K OR NA; AND N IS AN INTEGER OF 2 TO 6, AND CONTAINING A TOTAL OF 5-13 CARBON ATOMS IN THE X-CYZ-CF2)N GROUP TO ADSORB THE FLUORINATED CARBOXYLIC ACID ONTO THE BASIC ANION EXCHANGE RESIN, AND THEN CONTACTING THE AMINO EXCHANGE RESIN WITH AN AQUEOUS SOLUTION OF NH3 AS AN ELUENT TO TRANSFER THE FLUORINATED CARBOXYLIC ACID FROM THE ANION EXCHANGE RESIN INTO THE ELUENT TO ISOLATE THE FLUORINATED CARBOXYLIC ACID; AND SAID WEAK BASIC ANION EXCHANGE RESIN (A) CONTAINING AT LEAST ONE AMINE GROUP, AS AN EXCHANGE GROUP SELECTED FROM PRIMARY, SECONDARY AND TERTIARY AMINES, AND (B) HAVING A PH IN THE RANGE OF 0 TO 7.0.
Claim 3
Dependent Claim
43 words
A method according to claim 1 wherein the weak basic anion exchange resin is a copolymer selected from the group consisting of copolymers of styrene and divinyl benzene containing a weak base selected from the group consisting of primary, secondary and tertiary amines.
Claim 4
Dependent Claim
34 words
The method according to claim 1, wherein the pH value of the aqueous solution of the fluorinated carboxylic acid before the step of the anion exchange resin treatment, is adjusted to less than 4.
Claim 5
Dependent Claim
27 words
The method according to claim 1, wherein the concentration of the aqueous solution of NH3 to be used as the eluent ranges from 0.5 to 2.0 normal.
Claim 6
Dependent Claim
66 words
The method according to claim 1, in which said aqueous solution of fluorinated carboxylic acid is one selected from the group consisting of a mother liquid obtained after the fluorinated olefin polymer has been isolated by deposition from a polymer latex thereof and containing therein the fluorinated carboxylic acid, and a waste liquid obtained from washing the fluorinated olefin polymer as separated from the polymer latex.
References Cited (Backward Citations)
US2580325A
Cited
US2863889A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |