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US4179286A
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Silver free, low gold-noble metal alloys for firing of dental porcelain
Assignee: Evonik Operations GmbH
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Filing: 1979-01-17
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Granted: 1979-12-18
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Expires: 1999-01-17
Abstract
Abstract A silver free, low gold, noble metal alloy for firing on dental porcelain is prepared consisting of 30 to 55% gold, 30 to 60% palladium, 1 to 12% tin, 0 to 10% indium, 0.1 to 3% germanium, and 0.05 to 1% rhenium and/or 0.05 to 1% ruthenium.
Inventors
- 👤 Helmut Knosp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:50
CPC Classifications
C; C22; C22C; C22C5/00; C22C5/02; A; A61; A61K; A61K6/00; A61K6/80; A61K6/84; A61K6/844; C22C30/00; C22C5/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
55 words
A silver-free, low gold, noble metal alloy suitable for firing on dental porcelain consisting essentially of 30 to 55% gold, 30 to 60% palladium, 1 to 12% tin, 0 to 10% indium, 0.1 to 3% germanium and at least one member of the group consisting of 0.05 to 1% rhenium and 0.05 to 1% ruthenium.
Claim 2
Dependent Claim
55 words
A silver-free, low gold, noble metal alloy suitable for firing on dental porcelain consisting essentially of 30 to 55% gold, 30 to 60% palladium, 1 to 12% tin, 0 to 10% indium, 0.1 to 3% germanium and at least one member of the group consisting of 0.05 to 1% rhenium and 0.05 to 1% ruthenium.
Claim 3
Dependent Claim
24 words
An alloy according to claim 1 wherein the weight ratio of germanium to the total of rhenium and ruthenium is from 2 to 3:1.
Claim 4
Dependent Claim
17 words
An alloy according to claim 1 wherein the total of rhenium and ruthenium is 0.05 to 1%.
Claim 5
Dependent Claim
9 words
An alloy according to claim 3 free from indium.
Claim 6
Dependent Claim
8 words
An alloy according to claim 3 containing indium.
Claim 7
Dependent Claim
13 words
An alloy according to claim 5 wherein the indium is 0.05 to 9.45%.
Claim 8
Dependent Claim
39 words
An alloy according to claim 3 consisting of 31 to 53.9% gold, 31 to 59% palladium 1 to 12% tin, 0 to 9.45% indium 0.1 to 3% germanium and the total of rhenium and ruthenium is 0.05 to 1%.
Claim 9
Dependent Claim
9 words
An alloy according to claim 3 free from rhenium.
Claim 10
Dependent Claim
9 words
An alloy according to claim 3 free from ruthenium.
Claim 11
Dependent Claim
11 words
An alloy according to claim 3 containing both rhenium and ruthenium.
References Cited (Backward Citations)
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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) | 1982-12-17 | 1983-06-18 | 1983-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-17 | 1987-06-18 | 1987-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-17 | 1991-06-18 | 1991-12-18 | $7700.00 | Window Closed / Lapsed |