Patent EP0143991A2 successfully refreshed from Google Patents.
US4138314A
Expired / Lapsed
US
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Method of forming diaphragms from discrete thermoplastic fibers requiring no bonding or cementing
Assignee: BASF Corp
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Filing: 1977-07-05
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Granted: 1979-02-06
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Expires: 1997-07-05
Abstract
Abstract Diaphragms for electrolytic cells are prepared by depositing onto a cathode screen, discrete thermoplastic fibers. The fibers are highly branched, and which, when deposited form an entanglement or network thereof, which does not require bonding or cementing.
Inventors
- 👤 Arvind S. Patil
- 👤 Eugene Y. Weissman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:26
CPC Classifications
C; C25; C25B; C25B13/00; C25B13/04; C25B13/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
84 words
In a method for manufacturing a diaphragm for use in an electrolytic cell of the type comprising depositing a fiber onto an electrolytic cathode screen, the improvement comprising: (a) dispersing a slurry consisting essentially of highly branched thermoplastic fibers in a water-acetone medium containing a surfactant to form a slurry thereof said slurry being free of bonding or cementing agents, (b) depositing the slurry onto a cathode screen to form a diaphragm of entangled highly branched thermoplastic fibers thereon, (c) drying the deposited diaphragm.
Claim 2
Dependent Claim
84 words
In a method for manufacturing a diaphragm for use in an electrolytic cell of the type comprising depositing a fiber onto an electrolytic cathode screen, the improvement comprising: (a) dispersing a slurry consisting essentially of highly branched thermoplastic fibers in a water-acetone medium containing a surfactant to form a slurry thereof said slurry being free of bonding or cementing agents, (b) depositing the slurry onto a cathode screen to form a diaphragm of entangled highly branched thermoplastic fibers thereon, (c) drying the deposited diaphragm.
Claim 3
Dependent Claim
24 words
The improvement of claim 1 wherein the water and acetone are present in a respective, volumetric ratio ranging from about 0.5:1 to about 1:0.5.
Claim 4
Dependent Claim
29 words
The improvement of claim 1 wherein the surfactant is present in an amount ranging from about 0.01% to about 10% by weight, based on the weight of the slurry.
Claim 5
Dependent Claim
20 words
The improvement of claim 1 wherein the thermoplastic fiber is a fluorinated hydrocarbon and the surfactant is a fluorocarbon surfactant.
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) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |