US4670047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing finely divided spherical metal powders
Assignee: Osram Sylvania Inc
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Filing: 1986-09-12
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Granted: 1987-06-02
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Expires: 2006-09-12
Abstract
Abstract A process is disclosed for producing finely divided spherical metal powders. The process comprises forming a coating of a surface active agent which can be of the nonionic or anionic type on the surfaces of the particles of a metal powder, feeding the coated particles and a carrier gas into a high temperature zone and maintaining the particles in the zone for a sufficient time to melt at least about 50% by weight of the particles and to form droplets therefrom, and cooling the droplets to form metal particles having essentially a spherical shape with the majority of the particles having a size less than about 50 micrometers.
Inventors
- 👤 Nelson E. Kopatz
- 👤 Lori S. Pruyne
- 👤 Howard H. Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:05
CPC Classifications
B; B22; B22F; B22F1/00; B22F1/06; B22F1/065; B22F2998/00; B22F2998/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
109 words
A process comprising: a. forming a coating of a surface active agent selected from the group consisting of nonionic surface active agents and anionic surface active agents on the surfaces of the particles of a metal powder; b. feeding the resulting coated particles and a carrier gas into a high temperature zone and maintaining said particles in said zone for a sufficient time to melt at least about 50% by weight of said particles, and to form droplets therefrom; and c. cooling said droplets to form metal particles having essentially a spherical shape with a majority of said metal particles having a size of less than about 50 micrometers.
Claim 2
Dependent Claim
109 words
A process comprising: a. forming a coating of a surface active agent selected from the group consisting of nonionic surface active agents and anionic surface active agents on the surfaces of the particles of a metal powder; b. feeding the resulting coated particles and a carrier gas into a high temperature zone and maintaining said particles in said zone for a sufficient time to melt at least about 50% by weight of said particles, and to form droplets therefrom; and c. cooling said droplets to form metal particles having essentially a spherical shape with a majority of said metal particles having a size of less than about 50 micrometers.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein said metal is a precious metal.
Claim 4
Dependent Claim
12 words
A process according to claim 2 wherein said precious metal is silver.
Claim 5
Dependent Claim
17 words
A process according to claim 2 wherein said high temperature zone is created by a plasma torch.
Claim 6
Dependent Claim
14 words
A process according to claim 1 wherein said carrier gas is an inert gas.
Claim 7
Dependent Claim
15 words
A process according to claim 1 wherein essentially all of said metal particles are melted.
Claim 8
Dependent Claim
24 words
A process according to claim 1 wherein at least about 50% by weight of said particles have a size less than about 50 micrometers.
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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) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |