Patent US4305848A successfully refreshed from Google Patents.
US4305848A
Expired / Lapsed
US
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Method of producing high conductive sinters
Assignee: Tokai Rika Co Ltd
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Filing: 1979-11-21
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Granted: 1981-12-15
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Expires: 1999-11-21
Abstract
Abstract This application is directed to a method of manufacturing high conductive sinters of a conductive lanthanum, chromium composite oxide material in which the specific resistance is extremely reduced with a rise in temperature, and whereby an extremely superior sinter can be provided as a heat resisting conductive material. The method of manufacturing sinters in accordance with the present invention is free from the conventional disadvantages of manufacturing sinters with conductive composite oxides of La and Cr as major components, which serves to improve the sintering properties and qualities of the product. The sinters can be easily manufactured at a temperature as low as approximately 1,500 DEG C., which is lower than temperatures previously used.
Inventors
- 👤 Shigeyuki Hikita
- 👤 Tamotsu Horiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:31
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/42; C04B35/50; H; H01; H01B; H01B1/00; H01B1/06; H01B1/08; H01C; H01C17/00; H01C17/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
136 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 60% by weight of the La ion in the oxide is solid solution substituted by a rare earth element selected from the group consisting of Nd and Y ions, said method comprising (1) mixing an oxide or a carbonate of the metal La, Sr and Cr and rare earth element selected from the groups consisting of Nd and Y in an amount sufficient to replace 1 to 60% by weight of the La ion; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 2
Independent Claim
136 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 60% by weight of the La ion in the oxide is solid solution substituted by a rare earth element selected from the group consisting of Nd and Y ions, said method comprising (1) mixing an oxide or a carbonate of the metal La, Sr and Cr and rare earth element selected from the groups consisting of Nd and Y in an amount sufficient to replace 1 to 60% by weight of the La ion; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 3
Dependent Claim
13 words
A method according to claim 1 wherein the rare earth element is Nd.
Claim 4
Dependent Claim
13 words
A method according to claim 1 wherein the rare earth metal is Y.
Claim 5
Dependent Claim
23 words
A method according to claim 1 in which the composite oxide forming temperature is 1350° C. and the sintering temperature is 1500° C.
Claim 6
Independent Claim
116 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 20% by weight of the Cr ion in the oxide is solid solution substituted by a Co ion, said method comprising (1) mixing an oxide or a carbonate of the metals La, Sr, Cr, and Co in an amount sufficient to replace 1 to 20% of the Cr ion in a solid solution; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure and in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 7
Independent Claim
116 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 20% by weight of the Cr ion in the oxide is solid solution substituted by a Co ion, said method comprising (1) mixing an oxide or a carbonate of the metals La, Sr, Cr, and Co in an amount sufficient to replace 1 to 20% of the Cr ion in a solid solution; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure and in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 8
Dependent Claim
23 words
A method according to claim 5 in which the composite oxide forming temperature is 1350° C. and the sintering temperature is 1500° C.
Claim 9
Independent Claim
153 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 60% by weight of the La ion in a solid solution is replaced by an Nd or Y ion and 1 to 20% by weight of the Cr ion is replaced by a Co ion in a solid solution, said method comprising (1) mixing an oxide or a carbonate of the metals La, Sr, Cr, Co and Nd or Y in such amounts so that 1-20% of the Cr ion is replaced by the Co ion and 1-60% of the La ion is replaced by Nd or Y in solid solution; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 10
Independent Claim
153 words
A method of manufacturing highly conductive sinters consisting essentially of an oxide of La, Sr and Cr in which 1 to 60% by weight of the La ion in a solid solution is replaced by an Nd or Y ion and 1 to 20% by weight of the Cr ion is replaced by a Co ion in a solid solution, said method comprising (1) mixing an oxide or a carbonate of the metals La, Sr, Cr, Co and Nd or Y in such amounts so that 1-20% of the Cr ion is replaced by the Co ion and 1-60% of the La ion is replaced by Nd or Y in solid solution; (2) heating the mixture at temperatures sufficient to form a composite oxide of the aforementioned metals; (3) crushing the composite oxide and (4) sintering the composite oxide under pressure in an oxidation atmosphere at temperatures sufficient to produce a sintered product.
Claim 11
Dependent Claim
23 words
A method according to claim 6 in which the composite oxide forming temperature is 1350° C. and the sintering temperature is 1500° C.
Claim 12
Dependent Claim
25 words
A method according to claim 1 in which the sintered product has the composition (La 0 .3 Nd 0 .3 Sr 0 .4)CrO 3 .
Claim 13
Dependent Claim
30 words
A method according to claim 7 in which the sintered product has the composition (La 0 .3 Nd 0 .3 Sr 0 .4)(Cr 0 .99 Co 0 .01)O 3 .
Claim 14
Dependent Claim
30 words
A method according to claim 7 in which the sintered product has the composition (La 0 .3 Nd 0 .3 Sr 0 .4)(Cr 0 .95 Co 0 .05)O 3 .
Claim 15
Dependent Claim
30 words
A method according to claim 7 in which the sintered product has the composition (La 0 .3 Nd 0 .3 Sr 0 .4)(Cr 0 .9 Co 0 .1)O 3 .
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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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |