US4173662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming a fuel cell matrix
Assignee: RTX Corp
•
Filing: 1977-12-23
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Granted: 1979-11-06
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Expires: 1997-12-23
Abstract
Abstract A process for forming a fuel cell electrolyte matrix on the surface of an electrode involves passing the electrode through a vertically falling curtain or waterfall of the matrix material carried in a liquid vehicle. The coated electrode is then heat treated to remove the liquid vehicle, leaving a layer of matrix material on the electrode surface. This curtain coating process has been used to produce matrix layers of 2.5 mils having a variation in thickness of no more than 0.2 mils.
Inventors
- 👤 Robert C. Stewart, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:40
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8878; H01M4/8892; H01M4/8882; H01M4/8885; H01M8/00; H01M8/02; H01M8/0289; H01M8/0293; B; B05; B05D; B05D1/00; B05D1/30; B05D3/00; B05D3/02; B05D3/0254; B05D5/00; B05D5/08; B05D5/083; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
A process for making a fuel cell electrode/matrix element comprising the steps of: creating a continuous falling curtain of material having a viscosity of between 50 and 1000 centipoise and comprising between 15% and 60%, by weight, fuel cell electrolyte matrix material carried in a balance of liquid vehicle by flowing said curtain material through a slot of constant width between 25 and 80 mils, the rate of mass flow of the curtain being maintained substantially constant; passing a fuel cell electrode through said curtain at a constant speed to coat a surface of said electrode with said curtain material; and heat treating the coated electrode to remove the liquid vehicle leaving a layer of matrix material on the electrode surface.
Claim 2
Dependent Claim
121 words
A process for making a fuel cell electrode/matrix element comprising the steps of: creating a continuous falling curtain of material having a viscosity of between 50 and 1000 centipoise and comprising between 15% and 60%, by weight, fuel cell electrolyte matrix material carried in a balance of liquid vehicle by flowing said curtain material through a slot of constant width between 25 and 80 mils, the rate of mass flow of the curtain being maintained substantially constant; passing a fuel cell electrode through said curtain at a constant speed to coat a surface of said electrode with said curtain material; and heat treating the coated electrode to remove the liquid vehicle leaving a layer of matrix material on the electrode surface.
Claim 3
Dependent Claim
27 words
The process according to claim 1 wherein said curtain material comprises 45% to 55% matrix material, by weight, and has a viscosity between 175 and 700 centipoise.
Claim 4
Dependent Claim
23 words
The process according to claim 2 wherein said matrix material comprises at least 90% silicon carbide, by weight, and up to 10% binder.
Claim 5
Dependent Claim
18 words
The process according to claim 3 wherein said curtain material has a viscosity between 350 and 500 centipoise.
Claim 6
Dependent Claim
16 words
The process according to claim 2 wherein said slot width is between 30 and 50 mils.
Claim 7
Dependent Claim
21 words
The process according to claim 5 wherein said matrix material comprises at least 90% silicon carbide and a balance of polytetrafluoroethylene.
Claim 8
Dependent Claim
22 words
The process according to claim 6 wherein said liquid vehicle comprises water as a liquid carrier and polyethylene oxide as a thickener.
Claim 9
Dependent Claim
26 words
The process according to claim 1 wherein said layer of matrix material left on the surface of the electrode is between 2.0 and 10.0 mils thick.
Claim 10
Dependent Claim
35 words
The process according to claim 8 wherein said layer of matrix material varies in thickness by no more than 0.2 mil and includes at least 90% by weight silicon carbide and up to 10% binder.
References Cited (Backward Citations)
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US3407249A
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US3694310A
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US4008121A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |