US4175061A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing resistor paste
Assignee: Sumitomo Metal Mining Co Ltd
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Filing: 1978-02-21
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Granted: 1979-11-20
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Expires: 1998-02-21
Abstract
Abstract A method of manufacturing resistor paste having excellent voltage resistance properties, high resistivity and low TCR by fusing a mixture composed of 1 to 40 weight % of ruthenium dioxide, 40 to 85 weight % of lead oxide, 10 to 30 weight % of silica, 1 to 15 weight % of alumina and 0 to 5 weight % of another inorganic oxide at a temperature of 800° to 1,200° C., cooling and grinding the fused mixture, then adding a TCR modifier and an organic vehicle to the ground material, the TCR modifier being selected from the group consisting of 2 to 10 weight % ZrO 2 ; 3 to 15 weight % of Al 2 O 3 ; 0.5 to 20 weight % of tin oxide and a mixture of 0.5 to 20 weight % of tin oxide and up to 15 weight % of Al 2 O 3 , the sum of which does not exceed 25 weight % with respect to the total weight of the ground material and organic vehicle, and blending the admixture.
Inventors
- 👤 Kenji Fujimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:03
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/06; H01C17/065; H01C17/06506; H01C17/06513; H01C17/06533; H01C17/0654; C; C03; C03C; C03C14/00; C03C14/006; C03C3/00; C03C3/04; C03C3/062; C03C3/07; C03C3/072; C03C8/00; C03C8/02; C03C8/10; C03C8/14; C03C8/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
157 words
A method of manufacturing a resistor paste comprising the steps of (a) mixing together 1 to 40 weight percent ruthenium dioxide, 40 to 85 weight percent lead oxide, 10 to 30 weight percent silica, and 1 to 15 weight percent alumina to form a mixture, (b) fusing the mixture of step (a) at 800° to 1200° C., (c) cooling and grinding the fused mixture of step (b), and (d) adding a TCR modifier and an organic vehicle to the cooled and ground mixture of step (c), said TCR modifier being selected from the group consisting of 2 to 10 weight percent of ZrO 2 ; 0.5 to 20 weight percent of tin oxide; and 0.5 to 20 weight percent of tin oxide and up to 15 weight percent of Al 2 O 3 , the sum of which does not exceed 25 weight percent with respect to the total weight of the ground material and organic vehicle.
Claim 2
Independent Claim
157 words
A method of manufacturing a resistor paste comprising the steps of (a) mixing together 1 to 40 weight percent ruthenium dioxide, 40 to 85 weight percent lead oxide, 10 to 30 weight percent silica, and 1 to 15 weight percent alumina to form a mixture, (b) fusing the mixture of step (a) at 800° to 1200° C., (c) cooling and grinding the fused mixture of step (b), and (d) adding a TCR modifier and an organic vehicle to the cooled and ground mixture of step (c), said TCR modifier being selected from the group consisting of 2 to 10 weight percent of ZrO 2 ; 0.5 to 20 weight percent of tin oxide; and 0.5 to 20 weight percent of tin oxide and up to 15 weight percent of Al 2 O 3 , the sum of which does not exceed 25 weight percent with respect to the total weight of the ground material and organic vehicle.
Claim 3
Dependent Claim
30 words
The method of claim 1 wherein said TCR modifier consists of 0.5 to 20 weight percent of tin oxide, based on the total weight of ground material and organic material.
Claim 4
Dependent Claim
42 words
The method of claim 1 wherein up to 5 weight percent of inorganic oxides selected from the group consisting of MgO, CaO, BaO, B 2 O 3 , SrO, CdO, SnO and Bi 2 O 3 are adding to mixing step (a).
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the fusing temperature of step (b) is maintained on the mixture of step (a) for more than 30 minutes.
Claim 6
Dependent Claim
21 words
The method of claim 2 wherein said tin oxide is selected from the group consisting of stannic oxide and stannous oxide.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein the cooling in step (c) is effected by pouring the fused mixture of step (b) in water.
Claim 8
Dependent Claim
19 words
The method of claim 1 including (e) blending the TCR modifier, organic vehicle and ground mixture of step (d).
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein the TCR modifier consists of 3.0 weight percent of tin oxide and 4.0 weight percent of Al 2 O 3 .
Claim 10
Dependent Claim
17 words
The method of claim 1 wherein the organic vehicle comprises a pine oil solution of ethyl cellulose.
Claim 11
Independent Claim
110 words
A method of manufacturing a resistor paste comprising the steps of (a) mixing together 1 to 40 weight percent ruthenium dioxide, 40 to 85 weight percent lead oxide, 10 to 30 weight percent silica, and 1 to 15 weight percent alumina to form a mixture, (b) fusing the mixture of step (a) at 800° to 1200° C., cooling and grinding the fused mixture of step (b), and (d) adding a TCR modifier and an organic vehicle to the cooled and ground mixture of step (c), said TCR modifier consisting of 2 to 10 weight percent of ZrO 2 , based on the total weight of ground material and organic vehicle.
Claim 12
Independent Claim
110 words
A method of manufacturing a resistor paste comprising the steps of (a) mixing together 1 to 40 weight percent ruthenium dioxide, 40 to 85 weight percent lead oxide, 10 to 30 weight percent silica, and 1 to 15 weight percent alumina to form a mixture, (b) fusing the mixture of step (a) at 800° to 1200° C., cooling and grinding the fused mixture of step (b), and (d) adding a TCR modifier and an organic vehicle to the cooled and ground mixture of step (c), said TCR modifier consisting of 2 to 10 weight percent of ZrO 2 , based on the total weight of ground material and organic vehicle.
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) | 1982-11-19 | 1983-05-21 | 1983-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-19 | 1987-05-21 | 1987-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-19 | 1991-05-21 | 1991-11-20 | $7700.00 | Window Closed / Lapsed |