Patent US4477296A successfully refreshed from Google Patents.
US4477296A
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Method for activating metal particles
Assignee: EIDP Inc
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Filing: 1982-09-30
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Granted: 1984-10-16
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Expires: 2002-09-30
Abstract
Abstract A method for activating the surface of finely divided particles of conductive metals having a thin surface coating of an oxide of the conductive metal comprising the steps of (a) treating the surface with an aqueous solution of a reducing agent when the conductive metal is a noble metal and either a reducing agent for the oxide or an inorganic acid when the conductive metal is a base metal, (b) washing the surface of the treated particles with an aqueous liquid, and (c) drying the surface of the washed particles.
Inventors
- 👤 Kumaran M. Nair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 16:45
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/005; H01G4/008; H01G4/0085; B; B22; B22F; B22F1/00; B22F1/14; B22F1/145; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
138 words
A method for activating the surface of finely divided particles of conductive metals having a thin surface coating of oxide of the conductive metal comprising the steps of (a) treating the surface with an aqueous solution of a reducing agent for the oxide when the conductive metal is a noble metal and either a reducing agent for the oxide or an inorganic acid capable of reacting with the oxide to form a water-soluble salt of the metal ion when the conductive metal is a base metal, the reactive component of the aqueous solution being in molar excess of the oxide, (b) washing the surface of the treated particles with an aqueous liquid having a pH of 5.5-7.0 until essentially no change in pH takes place in the wash liquid, and (c) drying the surface of the washed particles.
Claim 2
Independent Claim
138 words
A method for activating the surface of finely divided particles of conductive metals having a thin surface coating of oxide of the conductive metal comprising the steps of (a) treating the surface with an aqueous solution of a reducing agent for the oxide when the conductive metal is a noble metal and either a reducing agent for the oxide or an inorganic acid capable of reacting with the oxide to form a water-soluble salt of the metal ion when the conductive metal is a base metal, the reactive component of the aqueous solution being in molar excess of the oxide, (b) washing the surface of the treated particles with an aqueous liquid having a pH of 5.5-7.0 until essentially no change in pH takes place in the wash liquid, and (c) drying the surface of the washed particles.
Claim 3
Dependent Claim
44 words
The method of claim 1 in which the conductive metal is a noble metal selected from the group consisting of palladium, gold, silver and mixtures and alloys thereof, and the reactive component of the aqueous treating solution is a reducing agent for the oxide.
Claim 4
Dependent Claim
27 words
The method of claim 2 in which the conductive metal is a mixture of palladium and silver and the reducing agent is H 3 PO 2 .
Claim 5
Dependent Claim
51 words
The method of claim 1 in which the conductive metal is a base metal selected from the group consisting of aluminum, copper, nickel, and mixtures and alloys thereof and the rective component of the aqueous treating solution is reactive with the oxide to form a water-soluble salt of the metal ion.
Claim 6
Dependent Claim
28 words
The method of claim 4 in which the inorganic acid is selected from the group consisting of HNO 3 , H 2 SO 4 , and phosphorus acids.
Claim 7
Dependent Claim
46 words
The method of claim 1 in which the conductive metal is a base metal selected from the group consisting of copper, nickel, aluminum and mixtures and alloys thereof, and the reactive component of the aqueous treating solution is a reducing agent for the conductive metal oxide.
Claim 8
Dependent Claim
16 words
The method of claim 6 in which the reducing agent is H 3 PO 2 .
Claim 9
Dependent Claim
27 words
The method of claim 1 in which the concentration of the reactive compound in the aqueous treating solution does not exceed 10% by weight of the solution.
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) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |