US4382904A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrode backing layer and method of preparing
Assignee: Diamond Shamrock Chemicals Co
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Filing: 1980-10-31
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Granted: 1983-05-10
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Expires: 2000-10-31
Abstract
Abstract This disclosure is directed to the preparation of cohesive, self-sustaining electrode backing layers by a method comprising mixing from about 20 to about 50 weight parts of polytetrafluoroethylene (PTFE) having a particle size ranging from 0.05 to 0.5 micron with from about 50 to about 80 weight parts of a partially fluorinated carbon black of the formula CF x , where x is from about 0.1 to about 0.18 and having particles of a size ranging from about 50 to about 3000 angstroms to produce an electrode backing layer having a combination of enhanced electrical conductivity and hydrophobicity.
Inventors
- 👤 Lawrence J. Gestaut
- 👤 Frank Solomon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:43
CPC Classifications
B; B01; B01J; B01J31/00; B01J31/26; B01J27/00; B01J27/06; B01J27/08; B01J27/12; B01J31/02; B01J31/06; B01J33/00; C; C01; C01B; C01B32/00; C09; C09C; C09C1/00; C09C1/44; C09C1/48; C09C1/56; C25; C25B; C25B11/00; C25B11/04; C25B11/051; C25B11/073; C25B11/091; C25B11/095; H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8817; H01M4/8821; H01M4/96; C01P; C01P2006/00; C01P2006/40; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
163 words
A method for preparing an electrically conductive, hydrophobic, cohesive, self-sustaining electrode wetproofing sheet for use with an oxygen cathode comprising the steps of: intimately mixing from about 50 to about 80 wt. percent partially fluorinated carbon black particles of the formula CF x , where x is from 0.1 to 0.18, with from about 20 to about 50 wt. percent of liquid dispersed polytetrafluoroethylenated particles, to form a polytetrafluoroethylenated carbon black mix that can include a wetting agent; drying the polytetrafluoroethylenated carbon black mix, removing any wetting agent associated with forming the polytetrafluoroethylenated carbon black mix; chopping the polytetrafluoroethylenated carbon mix to form a granular mix, and then forming the granular mix into a sheet by one of passing said granular mix through rollers heated to between about 65° C. and 90° C. and by dispersing said granular mix in a liquid dispersion medium capable of wetting said granular mix then filtering said granular mix from said dispersion on a salt bed-filter medium.
Claim 2
Independent Claim
163 words
A method for preparing an electrically conductive, hydrophobic, cohesive, self-sustaining electrode wetproofing sheet for use with an oxygen cathode comprising the steps of: intimately mixing from about 50 to about 80 wt. percent partially fluorinated carbon black particles of the formula CF x , where x is from 0.1 to 0.18, with from about 20 to about 50 wt. percent of liquid dispersed polytetrafluoroethylenated particles, to form a polytetrafluoroethylenated carbon black mix that can include a wetting agent; drying the polytetrafluoroethylenated carbon black mix, removing any wetting agent associated with forming the polytetrafluoroethylenated carbon black mix; chopping the polytetrafluoroethylenated carbon mix to form a granular mix, and then forming the granular mix into a sheet by one of passing said granular mix through rollers heated to between about 65° C. and 90° C. and by dispersing said granular mix in a liquid dispersion medium capable of wetting said granular mix then filtering said granular mix from said dispersion on a salt bed-filter medium.
Claim 3
Dependent Claim
15 words
A method as in claim 1 wherein said carbon black is an acetylene carbon black.
Claim 4
Dependent Claim
27 words
A method as in claim 1 wherein a particulate pore-former is added to the polytetrafluoroethylene/CF x =0.1 to 0.18 mix before formation of said layer or sheet.
Claim 5
Dependent Claim
13 words
A method as in claim 3 wherein said pore-former is a soluble pore-former.
Claim 6
Dependent Claim
13 words
A method as in claim 4 wherein said soluble pore-former is sodium carbonate.
Claim 7
Dependent Claim
13 words
A method as in claim 3 wherein said pore-former is a volatile pore-former.
Claim 8
Dependent Claim
13 words
A method as in claim 6 wherein said volatile pore-former is ammonium benzoate.
Claim 9
Dependent Claim
39 words
A method as in claim 1 wherein said wetproofing sheet is released from said salt bed-filter medium by washing said wetproofing layer on said salt bed-filter medium with a solvent for said salt, and then lightly pressing said sheet.
Claim 10
Dependent Claim
18 words
A method as in claim 8 wherein said soluble salt is sodium chloride and said solvent is water.
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) | 1986-05-09 | 1986-11-08 | 1987-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-09 | 1990-11-08 | 1991-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-09 | 1994-11-08 | 1995-05-10 | $7700.00 | Window Closed / Lapsed |