US4185131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen printing method for making an electrochemical cell electrode
Assignee: RTX Corp
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Filing: 1978-06-28
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Granted: 1980-01-22
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Expires: 1998-06-28
Abstract
Abstract Fuel cell electrodes of uniform quality are made on a continuous basis using screen printing. A wet floc is first made by floccing a co-suspension of carbon and hydrophobic polymer. The floc is dried, reduced to a fine powder, and re-suspended in an inking vehicle. The ink is then screen printed onto a porous substrate and the inking vehicle is removed such as by heating. The layer is compacted, sintered, and then catalyzed such as with platinum.
Inventors
- 👤 Glen J. Goller
- 👤 Vincent J. Petraglia
- 👤 George Dews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:03
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8803; H01M4/8807; H01M8/00; H01M8/02; H01M8/0202; H01M8/023; H01M8/0234; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
A method for making an electrochemical cell electrode comprising the steps of: floccing a co-suspension of carbon particles and hydrophobic fluorocarbon polymer particles; drying the floc so produced and reducing it to a powder; resuspending the floc powder in an inking vehicle to form an ink; screen printing the ink onto a porous substrate to form a layer; drying the layer to remove the inking vehicle; compacting the layer; sintering the compacted layer; and catalyzing the layer.
Claim 2
Independent Claim
77 words
A method for making an electrochemical cell electrode comprising the steps of: floccing a co-suspension of carbon particles and hydrophobic fluorocarbon polymer particles; drying the floc so produced and reducing it to a powder; resuspending the floc powder in an inking vehicle to form an ink; screen printing the ink onto a porous substrate to form a layer; drying the layer to remove the inking vehicle; compacting the layer; sintering the compacted layer; and catalyzing the layer.
Claim 3
Dependent Claim
11 words
The method according to claim 1 wherein the substrate is carbon.
Claim 4
Dependent Claim
12 words
The method according to claim 1 wherein the hydrophobic polymer is PTFE.
Claim 5
Dependent Claim
32 words
The method according to claim 1 wherein the step of reducing the floc to a powder includes reducing the floc to a particle size of less than about ten microns in diameter.
Claim 6
Dependent Claim
43 words
The method according to claim 1 wherein the step of floccing comprises blending isopropanol, distilled water, and aqueous suspension of PTFE, and carbon powder to form a uniform co-suspension of carbon powder and PTFE, and causing the solids in said co-suspension to floc.
Claim 7
Dependent Claim
18 words
The method according to claim 3 wherein the weight percent of solids in the printed ink is 14-18%.
Claim 8
Dependent Claim
27 words
The method according to claim 6 wherein the inking vehicle is one of the following liquids or combinations thereof: ethylene glycol, glycerin, dibasic alcohols, and tribasic alcohols.
Claim 9
Dependent Claim
68 words
The method for making an electrochemical cell electrode according to claim 1 wherein the hydrophobic polymer is PTFE; the inking vehicle is one of the following liquids or combinations thereof: ethylene glycol, glycerin, a dibasic alcohol and tribasic alcohols; the substrate is porous carbon; and the step of reducing the floc to a powder includes reducing the floc to a particle size of less than about ten microns.
Claim 10
Independent Claim
81 words
A method for making an electrochemical call electrode using a powder made by floccing a co-suspension of carbon particles and hydrophobic fluorocarbon polymer particles, drying the floc so-produced and reducing it to a powder, comprising the steps of: suspending the floc powder in an inking vehicle to form an ink; screen printing the ink onto a porous substrate to form a layer; drying the layer to remove the inking vehicle; compacting the layer; sintering the compacted layer; and, catalyzing the layer.
Claim 11
Independent Claim
81 words
A method for making an electrochemical call electrode using a powder made by floccing a co-suspension of carbon particles and hydrophobic fluorocarbon polymer particles, drying the floc so-produced and reducing it to a powder, comprising the steps of: suspending the floc powder in an inking vehicle to form an ink; screen printing the ink onto a porous substrate to form a layer; drying the layer to remove the inking vehicle; compacting the layer; sintering the compacted layer; and, catalyzing the layer.
Claim 12
Dependent Claim
26 words
The method according to claim 9 wherein the polymer is PTFE and the dry floc powder has a particle size of less than about ten microns.
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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) | 1983-01-21 | 1983-07-23 | 1984-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-21 | 1987-07-23 | 1988-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-21 | 1991-07-23 | 1992-01-22 | $7700.00 | Window Closed / Lapsed |