Patent US3770596A successfully refreshed from Google Patents.
US3770596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gold plating bath for barrel plating operations
Assignee: Auric Corp
•
Filing: 1972-07-21
•
Granted: 1973-11-06
•
Expires: 1992-07-21
Abstract
Abstract An alkali gold cyanide bath particularly suited for barrel plating operations. The bath includes a chelating phosphonic acid, with quantities of hydrazine and small amounts of arsenic and/or lead ion. Bipolarity effects in plated objects are minimized through use of the composition. The bath displays reduced tendencies to attack the base metal of objects being plated or to codeposit undesired metals with the gold. Improved distribution of deposited metal is enabled with the resultant plating having excellent aesthetic qualities, and superior bakeout characteristics.
Inventors
- 👤 M Bick
- 👤 J Lochet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:07
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/48
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
27 words
A composition according to claim 1, further including quantities of a soluble alkali-metal base adequate to adjust the pH of said bath to between 4.0 and 8.0.
Claim 2
Dependent Claim
19 words
A composition according to claim 2, wherein the pH of said composition is maintained at between 6.0 and 8.0.
Claim 3
Dependent Claim
15 words
A composition according to claim 3, wherein said phosphonic acid comprises ethylenediamine tetra methylenephosphonic acid.
Claim 4
Dependent Claim
20 words
A composition according to claim 4 wherein said ion agent is present in concentrations of less than about 12 mg/l.
Claim 5
Dependent Claim
21 words
A composition according to claim 5, wherein said ion comprises As in a concentration range of from 0.4 to 12 mg/l.
Claim 6
Dependent Claim
22 words
A composition according to claim 5, wherein said ion comprises Pb in a concentration range of from about 2 to 12 mg/L.
Claim 7
Dependent Claim
90 words
An electroplating bath for barrel plating of gold, comprising per liter of aqueous solution about 160 g ethylenediamine tetra methylenephosphonic acid; as a reducing agent and agent for improving bath throwing power, about 25 ml of hydrazine, calculated as 64 percent hydrazine; potassium gold cyanide in concentrations to provide about 8.2 g of gold, calculated as the metal; and as an agent for improving the distribution and aesthetic qualities of the deposit about 0.8 mg of arsenic ion; together with sufficient alkali-metal hydroxide to yield a pH of about 7.3.
Claim 8
Independent Claim
124 words
A method for improved electroplating of complex-shaped metallic articles comprising: subjecting said articles to electroplating in a barrel-type operation utilizing as an electroplating bath an aqueous solution of alkali gold cyanide, said gold being in concentrations of from about 2g/l to saturation; from 80 to 320 g/l of a dissolved chelating phosphonic acid; as an agent for reducing bipolarity effects, from about 5 ml to 100 ml/l of hydrazine calculated as 64 percent hydrazine; and as an agent for improving the distribution and aesthetic qualities of the deposit, one or more agents selected from the group consisting of arsenic and lead ion, said ion being in sufficient quantity to provide a smoother and more evenly distributed deposit than is obtained in the absence thereof.
Claim 9
Dependent Claim
20 words
A method in accordance with claim 9, wherein said ion is present in concentrations of less than about 12 mg/l.
Claim 10
Dependent Claim
21 words
A method in accordance with claim 10, wherein said plating operation is conducted at temperatures of from about 120* to 125*F.
Claim 11
Dependent Claim
23 words
A method in accordance with claim 10, wherein said ion comprises As in the concentration range of from about 0.4 to 12 mg/l.
Claim 12
Dependent Claim
23 words
A method in accordance with claim 10, wherein said ion comprises Pb in a concentration range of from about 2 to 12 mg/l.
Claim 13
Dependent Claim
15 words
A method according to claim 9, wherein said phosphonic acid comprises ethylenediamine tetra methylenephosphonic acid.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |