US3716462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copper plating on zinc and its alloys
Assignee: Individual
•
Filing: 1970-10-05
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Granted: 1973-02-13
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Expires: 1990-10-05
Abstract
Abstract Production of a uniform, continuous corrosion resistant bonded copper coating on a zinc or zinc alloy body, by a process which comprises contacting the zinc or zinc alloy body with an electroless copper plating composition or solution consisting essentially of a soluble copper salt, e.g., copper sulfate, a complexing agent, e.g., citric acid, and a reducing agent, e.g., sodium hypophosphite. The resulting zinc or zinc alloy body can then be contacted with a copper electroplating bath, and according to one embodiment the resulting copper plated zinc or zinc alloy body is then treated in a nickel electroplating solution, followed by treatment in a chromic acid electroplating solution, to provide a corrosion resistant bright attractive metal coating on the zinc or zinc alloy body. The above noted novel electroless copper plating composition, and the zinc or zinc alloy article coated with an electroless copper plating.
Inventors
- 👤 D Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:11
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/10; C25D5/12; C25D5/14; C23; C23C; C23C18/00; C23C18/16; C23C18/31; C23C18/38; C23C18/40; C25D5/34; C25D5/627
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
79 words
In the process of producing a uniform continuous bonded copper coating on a metal body selected from the group consisting of zinc and its alloys, the improvement which comprises contacting said metal body with an aqueous electroless copper plating solution consisting essentially of a soluble copper salt, a complexing agent, and a reducing agent, to form an electroless copper coating on said metal body, prior to electrodepositing a coating on said metal body in a subsequent metal electroplating bath.
Claim 2
Dependent Claim
79 words
In the process of producing a uniform continuous bonded copper coating on a metal body selected from the group consisting of zinc and its alloys, the improvement which comprises contacting said metal body with an aqueous electroless copper plating solution consisting essentially of a soluble copper salt, a complexing agent, and a reducing agent, to form an electroless copper coating on said metal body, prior to electrodepositing a coating on said metal body in a subsequent metal electroplating bath.
Claim 3
Dependent Claim
118 words
The process as defined in claim 1, said copper salt being selected from the group consisting of copper sulfate, copper chloride, copper nitrate, copper acetate and copper cyanide; said complexing agent being selected from the group consisting of carboxylic acids, pyrophosphoric acid, boric acid, and the alkali metal salts of said acids, ammonia, ammonium hydroxide, amines, amine and ammonium salts of said acids, and soluble cyanides; and said reducing agent being selected from the group consisting of hypophosphorus acid and soluble salts thereof, formaldehyde, thiosulfates, borohydrides, hydeoxylamine and hydrazine; the pH of said solution ranging from about 5.0 to about 13.0, and the temperature of said electroless copper plating solution being maintained between about 55*C and about boiling.
Claim 4
Dependent Claim
44 words
The process as defined in claim 2, said complexing agent being citric acid, and said reducing agent being an alkali metal hypophosphite, the pH of said solution ranging from about 5.0 to about 8.0, and said temperature ranging from about 55*C to about 100*C.
Claim 5
Dependent Claim
23 words
The process as defined in claim 3, said copper salt being copper sulfate and said temperature ranging from about 80 to about 95*C.
Claim 6
Dependent Claim
142 words
The process as defined in claim 4, the amount of said copper salt present ranging from about 1 to about 5 percent, by weight of the electroless copper plating solution, the amount of said complexing agent employed ranging from about one-half the amount of the copper salt to about 10 times the amount of said copper salt, and the amount of said reducing agent employed ranging from about one-fourth of the amount of the copper salt employed to about 3 times the amount of said copper salt present, said solution being adjusted to a pH of about 5.8 by the addition of sodium hydroxide, the temperature of treatment in said solution ranging from about 80 to about 95*C, said metal body being contacted in said electroless copper plating solution for a period ranging from about 10 minutes up to about 1 hour.
Claim 7
Dependent Claim
107 words
The process as defined in claim 5, and after treatment of said metal body in said electroless copper plating solution, contacting said metal body containing said electroless copper coating with an aqueous acid copper electroplating bath containing a soluBle copper salt, and forming a copper electroplate coating over said electroless copper coating, including additionally contacting said metal body containing said electroless copper and copper electroplate coatings, with a nickel electroplating solution containing a nickel salt, and depositing a nickel electroplate on said copper electroplate coating, and then contacting said metal body with an aqueous chromic acid electroplating solution, and depositing a chrome electroplate over said nickel electroplate.
Claim 8
Dependent Claim
16 words
The process as defined in claim 4, wherein the electroless copper plating solution additionally contains thiourea.
Claim 9
Dependent Claim
107 words
The process as defined in claim 3, and after treatment of said metal body in said electroless copper plating solution, contacting said metal body containing said electroless copper coating with an aqueous acid copper electroplating bath containing a soluble copper salt, and forming a copper electroplate coating over said electroless copper coating, including additionally contacting said metal body containing said electroless copper and copper electroplate coatings, with a nickel electroplating solution containing a nickel salt, and depositing a nickel electroplate on said copper electroplate coating, and then contacting said metal body with an aqueous chromic acid electroplating solution, and depositing a chrome electroplate over said nickel electroplate.
Claim 10
Dependent Claim
52 words
The process as defined in claim 3, and after treatment of said metal body in said electroless copper plating solution, contacting said metal body containing said electroless copper coating with an aqueous acid copper electroplating bath containing a soluble copper salt, and forming a copper electroplate coating over said electroless copper coating.
Claim 11
Dependent Claim
36 words
The process as defined in claim 2, wherein the electroless copper plating solution additionally contains up to 50 mg per liter of a sulfur-bearing compound selected from the group consisting of thiourea, thiosulfate and dimethyl sulfoxide.
Claim 12
Dependent Claim
52 words
The process as defined in claim 1, and after treatment of said metal body in said electroless copper plating solution, contacting said metal body containing said electroless copper coating with an aqueous acid copper electroplating bath containing a soluble copper salt, and forming a copper electroplate coating over said electroless copper coating.
Claim 13
Dependent Claim
62 words
The process as defined in claim 11, including additionally contacting said metal body containing said electroless copper and copper electroplate coatings, with a nickel electroplating solution containing a nickel salt, and depositing a nickel electroplate on said copper electroplate coating, and then contacting said metal body with an aqueous chromic acid electroplating solution, and depositing a chrome electroplate over said nickel electroplate.
Claim 14
Dependent Claim
88 words
The process as defined in claim 1, the amount of said copper salt present ranging from about 1 to about 5 percent, by weight of the electroless copper plating solution, the amount of said complexing agent employed ranging from about one-half the amount of the copper salt to about 10 times the amount of said copper salt, and the amount of said reducing agent employed ranging from about one-fourth of the amount of the copper salt employed to about 3 times the amount of said copper salt present.
Claim 15
Dependent Claim
45 words
The process as defined in claim 1, including contacting said metal body with a degreaser, and then contacting said metal body with an alkaline cleaner, to remove surface dirt and soils from said metal body, prior to contacting same with said electroless copper plating solution.
Claim 16
Dependent Claim
45 words
The process as defined in claim 1, and after treatment of said metal body in said electroless copper plating solution, contacting said metal body containing said electroless copper coating with a metal electroplating bath, and forming a metal electroplate coating over said electroless copper coating.
Claim 17
Dependent Claim
47 words
The process as defined in claim 1, including subjecting said metal body to anodic cleaning in an alKaline solution containing a soluble fluoride, followed by treatment of said metal body in an aqueous zincate solution, prior to contacting said metal body with said electroless copper plating 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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |