Patent US2525287A successfully refreshed from Google Patents.
US4518705A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three layer laminate
Assignee: Eltech Systems Corp
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Filing: 1982-09-28
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Granted: 1985-05-21
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Expires: 2002-09-28
Abstract
Abstract The disclosure is directed to preparing three-layer laminated electrodes suitable for use as oxygen (air) cathodes in chlor-alkali and other electrochemical cells, fuel cells and in other electrochemical applications. This three-layer laminate includes an active layer or sheet containing from about 60 to about 85 wt. % active carbon, the remainder being unsintered, fibrillated polytetrafluoroethylene in intimate admixture with said active carbon, said active layer laminated on its working surface to a current distributor and on its opposite surface to a porous, coherent, hydrophobic polytetrafluoroethylene-containing wetproofing layer.
Inventors
- 👤 Frank Solomon
- 👤 Charles Grun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:04
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8817; H01M4/8821; C; C25; C25B; C25B11/00; C25B11/04; C25B11/042; C25B11/043; H01M4/8663; H01M4/96; H01M8/00; H01M8/02; H01M8/0202; H01M8/023; H01M8/0234; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A process for forming an electrode comprising adding a dilute aqueous dispersion of polytetrafluoroethylene particles to an aqueous suspension of larger active carbon particles to discontinuously coat said active carbon particles with smaller polytetrafluoroethylene particles; shear blending said discontinuously coated particles to form an intimate mix of active carbon particles and attenuated and fibrillated polytetrafluoroethylene; comminuting said intimate mix to yield a granular mix; forming said granular mix into an active sheet; and laminating the working surface of said active sheet to a current distributor and the opposite surface thereof to a polytetrafluoroethylene-containing wetproofing layer.
Claim 2
Dependent Claim
95 words
A process for forming an electrode comprising adding a dilute aqueous dispersion of polytetrafluoroethylene particles to an aqueous suspension of larger active carbon particles to discontinuously coat said active carbon particles with smaller polytetrafluoroethylene particles; shear blending said discontinuously coated particles to form an intimate mix of active carbon particles and attenuated and fibrillated polytetrafluoroethylene; comminuting said intimate mix to yield a granular mix; forming said granular mix into an active sheet; and laminating the working surface of said active sheet to a current distributor and the opposite surface thereof to a polytetrafluoroethylene-containing wetproofing layer.
Claim 3
Dependent Claim
27 words
A process as in claim 1 wherein said granular mix is formed into a sheet by rolling it at temperatures of from about 60° to 90° C.
Claim 4
Dependent Claim
22 words
A process as in claim 1 wherein said active carbon particles have a particle size ranging from about 1 to 30 microns.
Claim 5
Dependent Claim
27 words
A process as in claim 1 wherein a pore-forming agent is added to said discontinuously coated active carbon particles and blended therewith prior to said shear blending.
Claim 6
Dependent Claim
17 words
A process as in claim 1 wherein said intimate mix is chopped to yield said granular mix.
Claim 7
Dependent Claim
24 words
A process as in claim 1 wherein said granular mix contains from about 60 to 85 wt.% active carbon particles, the remainder being polytetrafluoroethylene.
Claim 8
Dependent Claim
34 words
A process as in claim 1 wherein said active carbon particles have an ash content of less than about 4 wt.% and a B.E.T. surface area of about 1000 m 2 /g and higher.
Claim 9
Dependent Claim
25 words
A process as in claim 1 which includes depositing a precious metal catalyst on said active carbon particles before adding said dilute polytetrafluoroethylene dispersion thereto.
Claim 10
Dependent Claim
12 words
A process as in claim 8 wherein said precious metal is platinum.
Claim 11
Dependent Claim
12 words
A process as in claim 8 wherein said precious metal is silver.
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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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |