US4110153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a microporous diaphragm
Assignee: PPG Industries Inc
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Filing: 1977-09-08
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Granted: 1978-08-29
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Expires: 1997-09-08
Abstract
Abstract Disclosed is a method of forming an unsintered, nonwoven, wettable, microporous diaphragm of a fluorocarbon polymer. The diaphragm is prepared by maintaining a nonwoven, fibrous mat of a leachable material in contact with the external surfaces of the fluorocarbon polymer film while hot pressing the halocarbon polymer film above its flow temperature and below its thermal decomposition temperature, and thereafter leaching the fibrous mat out of the halocarbon film. Additionally, monomers having acidic or basic groups may be grafted to the pore walls. Also disclosed is a method of rendering a hydrophobic fluorocarbon polymer film wettable by compressing the film between a pair of nonwoven mats of a leachable fibrous material while maintaining the film above the flow temperature thereof but below its decomposition temperature and then leaching the fibrous material out of the film.
Inventors
- 👤 Thomas A. Rechlicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:54
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2287; C08J5/2293; H; H01; H01M; H01M50/00; H01M50/40; H01M50/403; H01M50/409; H01M50/411; H01M50/414; H01M50/426; C08J2327/00; C08J2327/02; C08J2327/12; H01M50/489; H01M50/491; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
55 words
A method of forming an unsintered, wettable, microporous polyfluorocarbon diaphragm comprising: maintaining a nonwoven mat of a leachable fibrous material in contact with the external surfaces of a polyfluorocarbon film while hot pressing the polyfluorocarbon film above the flow temperature thereof but below the thermal decomposition temperature thereof; and thereafter leaching out the fibrous material.
Claim 2
Independent Claim
55 words
A method of forming an unsintered, wettable, microporous polyfluorocarbon diaphragm comprising: maintaining a nonwoven mat of a leachable fibrous material in contact with the external surfaces of a polyfluorocarbon film while hot pressing the polyfluorocarbon film above the flow temperature thereof but below the thermal decomposition temperature thereof; and thereafter leaching out the fibrous material.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein the fluorocarbon has the repeating units: ##STR5## where R 1 is chosen from the group consisting of --CF 3 , --O--CF 2 --CF 3 , and --O--CF 2 --CF 2 --CF 3 .
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the fluorocarbon is a copolymer of tetrafluoroethylene and a perfluoro(alkyl vinyl ether).
Claim 5
Independent Claim
32 words
A method of rendering a hydrophobic fluorocarbon polymer film wettable comprising: compressing the film between a pair of nonwoven mats of a leachable, fibrous material; and thereafter leaching out the fibrous material.
Claim 6
Independent Claim
32 words
A method of rendering a hydrophobic fluorocarbon polymer film wettable comprising: compressing the film between a pair of nonwoven mats of a leachable, fibrous material; and thereafter leaching out the fibrous material.
Claim 7
Dependent Claim
39 words
The method of claim 4 wherein the fluorocarbon has the repeating units: ##STR6## where R 1 is chosen from the group consisting of --CF 3 , --O--CF 2 --CF 3 , and --O--CF 2 --CF 2 --CF 3 .
Claim 8
Dependent Claim
18 words
The method of claim 5 wherein the fluorocarbon is a copolymer of tetrafluoroethylene and a perfluoro(alkyl vinyl ether)
Claim 9
Independent Claim
90 words
A method of preparing a microporous diaphragm comprising a poly(fluorocarbon) with pendant active groups which method comprises: maintaining a nonwoven mat of a leachable fibrous material in contact with the external surfaces of a poly(fluorocarbon) film while hot pressing the poly(fluorocarbon) film above the flow temperature thereof but below the thermal decomposition temperature thereof; leaching the fibrous material out of the poly(fluorocarbon) film whereby to provide a network of pores within the poly(fluorocarbon) film; and grafting a monomer having vinyl unsaturation and active groups on the walls of the pores.
Claim 10
Independent Claim
90 words
A method of preparing a microporous diaphragm comprising a poly(fluorocarbon) with pendant active groups which method comprises: maintaining a nonwoven mat of a leachable fibrous material in contact with the external surfaces of a poly(fluorocarbon) film while hot pressing the poly(fluorocarbon) film above the flow temperature thereof but below the thermal decomposition temperature thereof; leaching the fibrous material out of the poly(fluorocarbon) film whereby to provide a network of pores within the poly(fluorocarbon) film; and grafting a monomer having vinyl unsaturation and active groups on the walls of the pores.
Claim 11
Dependent Claim
45 words
The method of claim 7 wherein the fluorocarbon has the repeating units: --CF.sub.2 --CF.sub.2 -- and --CF.sub.2 --CFR.sub.1 -- where R 1 is chosen from the group consisting of --CF 3 , --O--CF 2 --CF 3 , and --O--CF 2 --CF 2 --CF 3 .
Claim 12
Dependent Claim
39 words
The method of claim 7 wherein the monomer has the formula ##STR7## where A is chosen from the group consisting of acidic groups and basic groups and X is chosen from the group consisting of the halogens and hydrogen.
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) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |