US4735926A
Expired / Lapsed
US
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Alumina ceramic body
Assignee: Niterra Co Ltd
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Filing: 1986-03-14
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Granted: 1988-04-05
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Expires: 2006-03-14
Abstract
Abstract A dielectric alumina ceramic body having a constant dielectric loss tangent tan δ is obtained by sintering a composition consisting essentially of: 100 parts by weight of a ternary formulation consisting of 92.4 to 98.7 mol % Al 2 O 3 , at least 0.5 mol % CaO, and 1.3 to 7.6 mol % TiO 2 ; and at least one selected from the group consisting of Cr 2 O 3 and NiO subject to the relation of: ##EQU1## where x is the weight part of Cr 2 O 3 per 100 parts by weight of said formulation, y is the weight part of NiO per 100 parts by weight of said formulation, and z is the mol % of Al 2 O 3 in the formulation, provided that x≧0 and y≧0, except x=y=0.
Inventors
- 👤 Minato Ando
- 👤 Masaaki Ito
- 👤 Fumio Mizuno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:49
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
122 words
An alumina ceramic body obtained by sintering a composition consisting essentially of: 100 parts by weight of a ternary formulation consisting of 92.4 to 98.7 mol% Al 2 O 3 , and 1.3 to 7.6 mol% in total of CaO and TiO 2 , provided that the CaO is at least 0.5 mol%; and at least one selected from the group consisting of Cr 2 O 3 and NiO subject to the relation of: ##EQU11## where x is the weight part of Cr 2 O 3 per 100 parts by weight of said formulation, y is the weight part of NiO per 100 parts by weight of said formulation, and z is the mol% of Al 2 O 3 in the formulation.
Claim 2
Dependent Claim
122 words
An alumina ceramic body obtained by sintering a composition consisting essentially of: 100 parts by weight of a ternary formulation consisting of 92.4 to 98.7 mol% Al 2 O 3 , and 1.3 to 7.6 mol% in total of CaO and TiO 2 , provided that the CaO is at least 0.5 mol%; and at least one selected from the group consisting of Cr 2 O 3 and NiO subject to the relation of: ##EQU11## where x is the weight part of Cr 2 O 3 per 100 parts by weight of said formulation, y is the weight part of NiO per 100 parts by weight of said formulation, and z is the mol% of Al 2 O 3 in the formulation.
Claim 3
Dependent Claim
27 words
The alumina ceramic body as defined in claim 1, wherein x is 0.6 to 5 parts by weight, and y is 0.2 to 2 parts by weight.
Claim 4
Dependent Claim
27 words
The alumina ceramic body as defined in claim 2, wherein x is 0.7 to 3 parts by weight, and y is 0.3 to 1 parts by weight.
Claim 5
Dependent Claim
14 words
The alumina ceramic body as defined in claim 1, wherein said relation is: ##EQU12##
Claim 6
Dependent Claim
25 words
The alumina ceramic body as defined in claim 1, wherein the molar ratio of CaO to TiO 2 (CaO/TiO 2 ) is 0.8 to 1.3.
Claim 7
Dependent Claim
21 words
The alumina ceramic body as defined in claim 5, wherein the molar ratio of CaO to TiO 2 is about one.
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) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |