US4376140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a fluorinated copolymer membrane
Assignee: Asahi Kasei Corp
•
Filing: 1980-09-05
•
Granted: 1983-03-08
•
Expires: 2000-09-05
Abstract
Abstract A method for producing a fluorinated copolymer membrane comprising a first layer made from a fluorinated copolymer having pendant sulfonylchloride groups and a second layer made from a fluorinated copolymer having sulfonylfluoride groups. The membrane is treated with a reducing agent to introduce carboxylic acid groups onto the surface of said first layer. The membrane may be used as a cation exchange membrane. If necessary, a supporting material may be embedded in the second layer.
Inventors
- 👤 Kyoji Kimoto
- 👤 Mikio Ebisawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:39
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2218; C08J5/2231; C08J5/2237; C08J2327/00; C08J2327/02; C08J2327/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A method of producing a fluorinated copolymer membrane comprising a first layer substantially parallel to the surface of said membrane and said first layer being made from a fluorinated copolymer containing pendant sulfonylchloride groups, and a second layer substantially parallel to the surface of said membrane and said second layer being made from a fluorinated copolymer containing pendant sulfonylfluoride groups, which comprises bringing a starting fluorinated copolymer membrane into contact with phosphorous pentachloride or a mixture of phosphorous trichloride and chlorine at a temperature of 80°-140° C., said starting membrane comprising (1) a first layer substantially parallel to the membrane, said first layer being made from a fluorinated copolymer containing pendant sulfonic acid groups or salts thereof, and (2) a second layer substantially parallel to the membrane, said second layer being made from a fluorinated polymer containing pendant sulfonylfluoride groups.
Claim 2
Independent Claim
140 words
A method of producing a fluorinated copolymer membrane comprising a first layer substantially parallel to the surface of said membrane and said first layer being made from a fluorinated copolymer containing pendant sulfonylchloride groups, and a second layer substantially parallel to the surface of said membrane and said second layer being made from a fluorinated copolymer containing pendant sulfonylfluoride groups, which comprises bringing a starting fluorinated copolymer membrane into contact with phosphorous pentachloride or a mixture of phosphorous trichloride and chlorine at a temperature of 80°-140° C., said starting membrane comprising (1) a first layer substantially parallel to the membrane, said first layer being made from a fluorinated copolymer containing pendant sulfonic acid groups or salts thereof, and (2) a second layer substantially parallel to the membrane, said second layer being made from a fluorinated polymer containing pendant sulfonylfluoride groups.
Claim 3
Dependent Claim
19 words
A method as defined in claim 1, in which a supporting material is incorporated substantially in said second layer.
Claim 4
Dependent Claim
26 words
A method as defined in claim 2 or 1, in which the thickness of said first layer is 1/100-5/10 of the total thickness of the membrane.
Claim 5
Dependent Claim
25 words
A method as defined in claim 2 or 1, in which said second layer comprises two laminae each having a different density of sulfonylfluoride groups.
Claim 6
Dependent Claim
27 words
A method as defined in claim 1, in which the first layer of said starting fluorinated copolymer membrane contains pendant sulfonic acid groups and/or ammonium salts thereof.
References Cited (Backward Citations)
JPS4861582A
Cited
US3770567A
Cited
US3849243A
Cited
JPS5224176A
Cited
JPS5224177A
Cited
GB1523047A
Cited
US4151053A
Cited
JPS52134888A
Cited
JPS53104583A
Cited
JPS53116287A
Cited
JPS544289A
Cited
JPS546887A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-07 | 1986-09-06 | 1987-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-07 | 1990-09-06 | 1991-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-07 | 1994-09-06 | 1995-03-08 | $7700.00 | Window Closed / Lapsed |