Patent US4045374A successfully refreshed from Google Patents.
US4045374A
Expired / Lapsed
US
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Zinc oxide voltage-nonlinear resistor
Assignee: Panasonic Holdings Corp
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Filing: 1975-10-10
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Granted: 1977-08-30
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Expires: 1995-10-10
Abstract
Abstract A voltage-dependent resistor (varistor) of the bulk type comprising a sintered body consisting essentially of, as a main constituent, ZnO and additives of various metal oxides and further containing an additive of at least one of Al2O3, In2O3 Ga2O3 provide much improved characteristics, especially superior limiting voltage ratio, surge resistance and life of the varistor.
Inventors
- 👤 Masahiro Nagasawa
- 👤 Yasuo Wakahata
- 👤 Kensuke Kuchiba
- 👤 Kunio Nishi
- 👤 Hiroshi Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:55
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/108; H01C7/112
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
127 words
A voltage-dependent resistor of bulk type comprising a sintered body consisting essentially of a voltage-dependent composition which comprises, as a main constituent, zinc oxide (ZnO) and, as an additive, at least one member selected from the group consisting of bismuth oxide (Bi 2 O 3 ), barium oxide (BaO), strontium oxide (SrO), lead oxide (PbO) and uranium oxide (UO 2 ), and, as a further additive, at least one member selected from the group consisting of aluminum oxide (Al 2 O 3 ), indium oxide (In 2 O 3 ) and gallium oxide (Ga 2 O 3 ) in an amount of 1 × 10.sup. -4 to 5 × 10.sup. -3 mole per 100 moles of ZnO, and electrodes applied to opposite surfaces of said sintered body.
Claim 2
Dependent Claim
127 words
A voltage-dependent resistor of bulk type comprising a sintered body consisting essentially of a voltage-dependent composition which comprises, as a main constituent, zinc oxide (ZnO) and, as an additive, at least one member selected from the group consisting of bismuth oxide (Bi 2 O 3 ), barium oxide (BaO), strontium oxide (SrO), lead oxide (PbO) and uranium oxide (UO 2 ), and, as a further additive, at least one member selected from the group consisting of aluminum oxide (Al 2 O 3 ), indium oxide (In 2 O 3 ) and gallium oxide (Ga 2 O 3 ) in an amount of 1 × 10.sup. -4 to 5 × 10.sup. -3 mole per 100 moles of ZnO, and electrodes applied to opposite surfaces of said sintered body.
Claim 3
Dependent Claim
17 words
A voltage-dependent resistor according to claim 1, wherein said further additive is Ga 2 O 3 .
Claim 4
Dependent Claim
17 words
A voltage-dependent resistor according to claim 1, wherein said further additive is Al 2 O 3 .
Claim 5
Dependent Claim
50 words
A voltage-dependent resistor according to claim 1, wherein said voltage dependent composition further comprises at least one member selected from the group consisting of cobalt oxide (CoO), manganese oxide (MnO), antimony oxide (Sb 2 O 3 ), chromium oxide (Cr 2 O 3 ) and silicon oxide (SiO 2 ).
Claim 6
Dependent Claim
85 words
A voltage-dependent resistor according to claim 1, wherein said voltage-dependent composition comprises 80 to 99.95 mole % of ZnO, 0.01 to 10 mole % of Bi 2 O 3 , 0.01 to 10 mole % of CoO, 0.01 to 10 mole % of MnO, 0.01 to 10 mole % of Sb 2 O 3 and 0.01 to 10 mole % of at least one member selected from the group consisting of Cr 2 O 3 , SnO 2 , SiO 2 , NiO and MgO.
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) | 1980-08-29 | 1981-02-28 | 1981-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-29 | 1985-02-28 | 1985-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-29 | 1989-02-28 | 1989-08-30 | $7700.00 | Window Closed / Lapsed |