Patent US574570A successfully refreshed from Google Patents.
Patent US4055438A successfully refreshed from Google Patents.
US4055438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Barium titanate ceramic
Assignee: NGK Insulators Ltd
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Filing: 1975-07-11
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Granted: 1977-10-25
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Expires: 1995-07-11
Abstract
Abstract A ceramic is disclosed which maintains a high electric resistance over a wide temperature range and has a large temperature coefficient of resistance variation at temperatures just below the aforesaid range, the PTC ceramic consisting essentially of 100 parts by weight of four ingredients including A. 1 mol of barium titanate composition, B. 0.003 to 0.05 mol of titania, C. 0.003 to 0.05 mol of alumina, and D. 0.005 to 0.06 mol of silica; 0.05 to 0.3 part by weight of E. tantalum pentoxide and/or antimony pentoxide; and 0.005 to 0.03 part by weight of F. manganese and/or copper.
Inventors
- 👤 Shigetaka Wada
- 👤 Senji Atsumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:16
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: 14
Claim 1
Independent Claim
169 words
A ceramic having a positive temperature coefficient of electric resistance, consisting essentially of: 100 parts by weight of four ingredients including a. 1 mol of one barium titanate composition which is selected from the group consisting of barium titanate, 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate, 0.0001 to 0.4 mol of strontium titanate and the remainder of barium titanate, and 0.0001 to 0.15 mol of barium stannate and the remainder of barium titanate, b. 0.003 to 0.05 mol of titania, c. 0.003 to 0.05 mol of alumina, and d. 0.005 to 0.06 mol of silica; 0.05 to 0.3 part by weight of at least one oxide selected from the group consisting of tantalum pentoxide and antimony pentoxide based on the preceding 100parts by weight of ingredients (a) to (d); and 0.005 to 0.03 part by weight of at least one metal selected from the group consisting of manganese and copper based on the preceding 100 parts by weight of ingredients (a) to (d).
Claim 2
Dependent Claim
169 words
A ceramic having a positive temperature coefficient of electric resistance, consisting essentially of: 100 parts by weight of four ingredients including a. 1 mol of one barium titanate composition which is selected from the group consisting of barium titanate, 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate, 0.0001 to 0.4 mol of strontium titanate and the remainder of barium titanate, and 0.0001 to 0.15 mol of barium stannate and the remainder of barium titanate, b. 0.003 to 0.05 mol of titania, c. 0.003 to 0.05 mol of alumina, and d. 0.005 to 0.06 mol of silica; 0.05 to 0.3 part by weight of at least one oxide selected from the group consisting of tantalum pentoxide and antimony pentoxide based on the preceding 100parts by weight of ingredients (a) to (d); and 0.005 to 0.03 part by weight of at least one metal selected from the group consisting of manganese and copper based on the preceding 100 parts by weight of ingredients (a) to (d).
Claim 3
Dependent Claim
25 words
The ceramic according to claim 1, wherein said barium titanate composition is 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate.
Claim 4
Dependent Claim
17 words
The ceramic according to claim 1, wherein the quantity of said titania is 0.01 to 0.03 mol.
Claim 5
Dependent Claim
17 words
The ceramic according to claim 1, wherein the quantity of said alumina is 0.005 to 0.025 mol.
Claim 6
Dependent Claim
17 words
The ceramic according to claim 1, wherein the quantity of said silica is 0.01 to 0.04 mol.
Claim 7
Dependent Claim
19 words
The ceramic according to claim 1, wherein the quantity of said oxide is 0.1 to 0.2 part by weight.
Claim 8
Dependent Claim
19 words
The ceramic according to claim 1, wherein the quantity of said metal is 0.01 to 0.02 part by weight.
Claim 9
Dependent Claim
170 words
A ceramic having a positive temperature coefficient of electric resistance, consisting essentially of: 100 parts by weight of four ingredients including a. 1 mol of one barium titanate composition which is selected from the group consisting of barium titanate, 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate, 0.0001 to 0.4 mol of strontium titanate and the remainder of barium titanate, and 0.001 to 0.15 mol of barium stannate and the remainder of barium titanate, b. 0.01 to 0.03 mol of titania, c. 0.005 to 0.25 mol of alumina, and d. 0.01 to 0.04 mol of silica; 0.1 to 0.2 part by weight of at least one oxide selected from the group consisting of tantalum pentoxide and antimony pentoxide based on the preceding 100 parts by weight of ingredients (a) to (d); and 0.01 to 0.02 part by weight of at least one metal selected from the group consisting of manganese and copper based on the preceding 100 parts by weight of ingredients (a) to (d).
Claim 10
Dependent Claim
170 words
A ceramic having a positive temperature coefficient of electric resistance, consisting essentially of: 100 parts by weight of four ingredients including a. 1 mol of one barium titanate composition which is selected from the group consisting of barium titanate, 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate, 0.0001 to 0.4 mol of strontium titanate and the remainder of barium titanate, and 0.001 to 0.15 mol of barium stannate and the remainder of barium titanate, b. 0.01 to 0.03 mol of titania, c. 0.005 to 0.25 mol of alumina, and d. 0.01 to 0.04 mol of silica; 0.1 to 0.2 part by weight of at least one oxide selected from the group consisting of tantalum pentoxide and antimony pentoxide based on the preceding 100 parts by weight of ingredients (a) to (d); and 0.01 to 0.02 part by weight of at least one metal selected from the group consisting of manganese and copper based on the preceding 100 parts by weight of ingredients (a) to (d).
Claim 11
Dependent Claim
14 words
The ceramic according to claim 8, wherein said barium titanate composition is barium titanate.
Claim 12
Dependent Claim
25 words
The ceramic according to claim 8, wherein said barium titanate composition is 0.0001 to 0.35 mol of lead titanate and the remainder of barium titanate.
Claim 13
Dependent Claim
12 words
The ceramic according to claim 8, wherein said oxide is antimony pentoxide.
Claim 14
Dependent Claim
11 words
The ceramic according to claim 8, wherein said metal is manganese.
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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) | 1980-10-24 | 1981-04-25 | 1981-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-24 | 1985-04-25 | 1985-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-24 | 1989-04-25 | 1989-10-25 | $7700.00 | Window Closed / Lapsed |