US3768994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gold powder
Assignee: OI Glass Inc
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Filing: 1971-03-15
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Granted: 1973-10-30
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Expires: 1991-03-15
Abstract
Abstract Gold powder useful in the formation of thick film microelectronic circuitry is formed by dissolving a gold bearing material in aqua regia, thereafter adding to the solution so formed a sufficient amount of an emulsifying agent or a particle size inhibitor such that upon precipitation of the gold from the solution, the average particle size of the precipitate will be less than about 20 microns, and thereafter adding, in a rapid fashion, a precipitating agent to the solution in an amount sufficient to precipitate the gold from the solution. The freshly formed gold particles are encapsulated with the emulsifier and a powder formed. By using the described tenchinque, the powder so formed, after washing and drying, generally has a bulk density of greater than about 5.0 grams per cc. and each of the fine particles of gold have a coating of the emulsifying agent that acts as a lubricant when used with an organic binder in a thick film printing formulation.
Inventors
- 👤 V Daiga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:19
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04; C01; C01P; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/80; C01P2006/00; C01P2006/10; H; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
39 words
A method of forming a gold powder in accordance with claim 1 wherein the bulk density of the powder is greater than about 6.8 grams/cc. and the average particle size of the powder is less than about 5 microns.
Claim 2
Dependent Claim
31 words
A method in accordance with claim 1 which also includes the step of removing the precipitate from said solution and drying said precipitate to form a substantially dry, pure gold powder.
Claim 3
Dependent Claim
22 words
A method in accordance with claim 1 wherein said precipitation is effected by the addition of a reducing agent to said solution.
Claim 4
Dependent Claim
38 words
A method in accordance with claim 4 wherein said reducing agent is added rapidly to said solution and said addition is accompanied by agitation of the solution in an amount sufficient to place the solution in turbulent flow.
Claim 5
Dependent Claim
45 words
A method in accordance with claim 1 which also includes the step of, prior to adding the emulsifying agent to said solution, heating said solution at a temperature below its boiling point for a sufficient period of time to remove substantially all nitric acid therefrom.
Claim 6
Dependent Claim
61 words
A method in accordance with claim 6 which also includes the step of adjusting the concentration of the solution prior to precipitation such that the concentration of the gold in the solution is in an amount of from about 1 part by weight gold: 2.5 parts by volume solution to about 1 part by weight gold: 100 parts by volume solution.
Claim 7
Dependent Claim
32 words
A method in accordance with claim 7 wherein the concentration of gold is adjusted prior to precipitation to an amount of about 1 part by weight gold: 20 parts by volume solution.
Claim 8
Dependent Claim
23 words
A method in accordance with claim 1 wherein said gold bearing material is substantially pure refined gold and said acid is aqua regia.
Claim 9
Dependent Claim
16 words
A method in accordance with claim 9 wherein the ratio of HCl: HNO3 is about 2:1.
Claim 10
Dependent Claim
18 words
A method in accordance with claim 1 wherein said emulsifying agent is an ester of a fatty acid.
Claim 11
Dependent Claim
27 words
A method in accordance with claim 11 wherein said emulsifying agent is a fatty acid represented by the formula CnH2 COOH wherein n is greater than 10.
Claim 12
Dependent Claim
14 words
A method in accordance with claim 1 wherein said emulsifying agent is butyl stearate.
Claim 13
Dependent Claim
33 words
A method in accordance with claim 1 wherein said emulsifying agent is a fatty acid and is employed in an amount of 1 part by volume inhibitor to 500 parts by volume solution.
Claim 14
Dependent Claim
21 words
A method in accordance with claim 1 wherein said precipitation is carried out at a temperature not exceeding about 50* C.
Claim 15
Dependent Claim
39 words
A method as defined in claim 1 in which the emulsifying agent is an alkyl ester of an aliphatic monocarboxylic acid, the acid having 12 to 22 carbon atoms and the alkyl group having two to six carbon atoms.
References Cited (Backward Citations)
US2086384A
Cited
US3558288A
Cited
US3421885A
Cited
US3576620A
Cited
US3539114A
Cited
US3542540A
Cited
US3565608A
Cited
US3473921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |