Patent US2326402A successfully refreshed from Google Patents.
US4096098A
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US
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Semiconductor ceramic composition
Assignee: TDK Corp
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Filing: 1975-11-17
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Granted: 1978-06-20
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Expires: 1995-11-17
Abstract
Abstract A semiconductor ceramic composition having positive temperature characteristics which comprises titanates of barium, lead and calcium which have 1 - 40 mole % of lead titanate and 1 - 22 mole % of calcium titanate and 38 - 98 mole % of barium titanate and 0.03 - 0.6 mole % of a semiconductor-forming component based on said titanates.
Inventors
- 👤 Kazumasa Umeya
- 👤 Kazunari Yonezuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:15
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/465; C04B35/468; C04B35/4682; C04B35/4684; H; H01; H01C; H01C7/00; H01C7/02; H01C7/022; H01C7/023; H01C7/025
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
102 words
A semiconductor ceramic composition having positive temperature characteristics, which comprises: (a) titanates of barium, lead and calcium which have 1 - 40 mole % of lead titanate, 1 - 22 mole % of calcium titanate and 38 - 98 mole % of barium titanate, wherein said contents of barium, lead and calcium titanates are based on 100 mole % of titanate present in said composition; and (b) 0.03 - 0.6 mole % of a semiconductor forming component of a metal derived from the metal oxides selected from the group consisting of Nb, Ta, Bi, Sb, W, and the rare earth element oxides.
Claim 2
Dependent Claim
102 words
A semiconductor ceramic composition having positive temperature characteristics, which comprises: (a) titanates of barium, lead and calcium which have 1 - 40 mole % of lead titanate, 1 - 22 mole % of calcium titanate and 38 - 98 mole % of barium titanate, wherein said contents of barium, lead and calcium titanates are based on 100 mole % of titanate present in said composition; and (b) 0.03 - 0.6 mole % of a semiconductor forming component of a metal derived from the metal oxides selected from the group consisting of Nb, Ta, Bi, Sb, W, and the rare earth element oxides.
Claim 3
Dependent Claim
19 words
The semiconductor ceramic composition of claim 1 which further comprises 0.06 - 0.9 wt. % of SiO 2 .
Claim 4
Dependent Claim
17 words
The semiconductor ceramic composition of claim 1 which further comprises 0.002 - 0.03 wt. % of Mn.
Claim 5
Dependent Claim
26 words
The semiconductor ceramic composition of claim 1 which further comprises 0.06 - 0.9 wt. % of SiO 2 and 0.002 - 0.03 wt. % of Mn.
Claim 6
Dependent Claim
89 words
The semiconductor ceramic composition of claim 1, which is produced by mixing sources of barium titanate, lead titanate, calcium titanate and said semiconductor-forming component of a metal selected from the group consisting of Nb, Ta, Bi, Sb, W and the rare earth elements, wherein said source of said semiconductor-forming component is an oxide or a compound of said metal convertible to an oxide, calcining the mixture at a temperature of 1000° - 1200° C, crushing, molding and then sintering said mixture at a temperature of 1230° - 1330° C.
Claim 7
Dependent Claim
22 words
The semiconductor ceramic composition of claim 1, wherein the semiconductor-forming component is an oxide of yttrium, niobium, tantalum, bismuth, antimony or tungsten.
Claim 8
Dependent Claim
14 words
The semiconductor ceramic composition of claim 6, wherein the semiconductor-forming component is yttrium oxide.
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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) | 1981-06-19 | 1981-12-19 | 1982-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-19 | 1985-12-19 | 1986-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-19 | 1989-12-19 | 1990-06-20 | $7700.00 | Window Closed / Lapsed |