US4477487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing oxygen concentration cells
Assignee: Niterra Co Ltd
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Filing: 1983-02-25
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Granted: 1984-10-16
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Expires: 2003-02-25
Abstract
Abstract An oxygen concentration cell having a high peeling resistance of the electrode and an excellent response property can be obtained by a method wherein electrode-adhering particles, which consist essentially of a specifically limited amount of stabilized or partially stabilized zirconia granulated particles having a spherical shape and a particle size of not smaller than 44 μm and a specifically limited amount of stabilized or partially stabilized zirconia fine particles having a particle size of not larger than 10 μm as a sintering aid, are applied and adhered to the surface of a matrix consisting of stabilized or partially stabilized zirconia, the resulting assembly is sintered to form monolithically a large number of convex portions on the matrix surface, an electrode is adhered to the matrix surface having the convex portions monolithically formed thereon, and further a heat-resistant ceramic protecting film is adhered to the electrode film.
Inventors
- 👤 Takao Kojima
- 👤 Naoto Naganuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:44
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/407; G01N27/4075
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
194 words
A method for producing an oxygen concentration cell suitable for exposure to high temperature combustion gases which comprises the steps of: (a) forming a green matrix by press molding a stabilized or partially stabilized zirconia raw material powder; (b) producing electrode-adhering particles made of stabilized or partially stabilized zirconia granulated particles which have a substantially spherical shape and which contain no less than fifty percent by weight of granulated particles having a size of at least 44 microns and no less than ten percent by weight of fine particles having a size of no greater than ten microns to act as a sintering aid, said electrode-adhering particles being produced through granulation by spray drying fine primary particles; (c) preparing fluidized electrode-adhering particles by adding an organic binder to said electrode-adhering particles; (d) applying said fluidized electrode-adhering particles to a surface of said green matrix; (e) sintering the green matrix and the applied electrode-adhering particles to form a monolithic matrix having a plurality of convex portions on the surface of the sintered matrix; (f) applying an electrode to the surface of the sintered matrix; and (g) applying a heat-resistant ceramic protective film to the electrode.
Claim 2
Independent Claim
194 words
A method for producing an oxygen concentration cell suitable for exposure to high temperature combustion gases which comprises the steps of: (a) forming a green matrix by press molding a stabilized or partially stabilized zirconia raw material powder; (b) producing electrode-adhering particles made of stabilized or partially stabilized zirconia granulated particles which have a substantially spherical shape and which contain no less than fifty percent by weight of granulated particles having a size of at least 44 microns and no less than ten percent by weight of fine particles having a size of no greater than ten microns to act as a sintering aid, said electrode-adhering particles being produced through granulation by spray drying fine primary particles; (c) preparing fluidized electrode-adhering particles by adding an organic binder to said electrode-adhering particles; (d) applying said fluidized electrode-adhering particles to a surface of said green matrix; (e) sintering the green matrix and the applied electrode-adhering particles to form a monolithic matrix having a plurality of convex portions on the surface of the sintered matrix; (f) applying an electrode to the surface of the sintered matrix; and (g) applying a heat-resistant ceramic protective film to the electrode.
Claim 3
Dependent Claim
20 words
The method of claim 1 in which said granulated particles have an average particle size of 50 to 100 μm.
Claim 4
Dependent Claim
71 words
The method of claim 1 in which the raw material powder of the press-molded matrix, the primary particles of the granulated particles and the fine particles of the sintering aid are all fine particles having a particle size of not larger than 10 μm and in which the electrode-adhering particles produced therefrom contain not less than 60% by weight of the granulated particles having a size not smaller than 44 μm.
Claim 5
Dependent Claim
27 words
The method of claim 1 in which the granulated particles are applied and adhered to the press-molded matrix surface in the form of one or several layers.
Claim 6
Dependent Claim
44 words
The method of claim 1 in which the granulated particles are first adhered to the press-molded matrix surface and then the fine particles are adhered to a film of the granulated particles to form a film of the electrode-adhering particles on the matrix surface.
Claim 7
Dependent Claim
47 words
The method of claim 1 in which the granulated particles are produced by granulating a raw material mixture of stabilized or partially stabilized zirconia raw material powders having up to 5% by weight of a sintering aid based on the amount of the zirconia raw material powders.
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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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |