US4356069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stripping composition and method for preparing and using same
Assignee: ELECTROPLATING Inc A CORP OF TENN
•
Filing: 1981-03-09
•
Granted: 1982-10-26
•
Expires: 2001-03-09
Abstract
Abstract An aqueous solution of chromic acid, peroxide, and sulfuric acid is prepared as a stripping composition. The stripping composition is intended for use in the reverse current stripping of plated metal substrates, such as chrome and/or nickel plated metal substrate, to prepare the metal substrate for replating.
Inventors
- 👤 Ross Cunningham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:33
CPC Classifications
C; C25; C25F; C25F5/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
135 words
A method for stripping chromium or nickel from the surface of a chromium or nickel plated metal substrate selected from the group consisting of zinc, steel, aluminium, brass and copper, comprising: (a) immersing said plated metal substrate in a bath containing an aqueous solution of chromic acid, peroxide, and sulfuric acid in sufficient concentrations to remove said chromium or nickel from said plated metal substrate in a reverse current stripping process, (b) immersing a metal cathode in said bath, (c) applying a positive potential to said plated metal substrate and a negative potential to said metal cathode with a direct current therebetween at a sufficient current density and for a sufficient period of time to strip said chromium or nickel from said plated metal substrate, and (d) removing the stripped metal substrate from said bath.
Claim 2
Independent Claim
135 words
A method for stripping chromium or nickel from the surface of a chromium or nickel plated metal substrate selected from the group consisting of zinc, steel, aluminium, brass and copper, comprising: (a) immersing said plated metal substrate in a bath containing an aqueous solution of chromic acid, peroxide, and sulfuric acid in sufficient concentrations to remove said chromium or nickel from said plated metal substrate in a reverse current stripping process, (b) immersing a metal cathode in said bath, (c) applying a positive potential to said plated metal substrate and a negative potential to said metal cathode with a direct current therebetween at a sufficient current density and for a sufficient period of time to strip said chromium or nickel from said plated metal substrate, and (d) removing the stripped metal substrate from said bath.
Claim 3
Independent Claim
56 words
A method for preparing stripping composition, comprising: (a) adding 225-1500 ml of a 20-25% concentration chromic acid solution per gallon of 55°-35° Baume sulfuric acid, (b) cooling the chromic acid-sulfuric acid solution, and (c) adding 100-300 ml of a 35% concentration hydrogen peroxide per gallon of chromic acid-sulfuric acid solution to said chromic acid-sulfuric acid solution.
Claim 4
Independent Claim
56 words
A method for preparing stripping composition, comprising: (a) adding 225-1500 ml of a 20-25% concentration chromic acid solution per gallon of 55°-35° Baume sulfuric acid, (b) cooling the chromic acid-sulfuric acid solution, and (c) adding 100-300 ml of a 35% concentration hydrogen peroxide per gallon of chromic acid-sulfuric acid solution to said chromic acid-sulfuric acid solution.
Claim 5
Dependent Claim
47 words
A stripping composition for use in reverse current stripping of plated metal substrates, comprising: (a) 6-38 parts by volume of a 20-25% aqueous chromic acid solution, (b) 2-8 parts by volume of a 35% aqueous hydrogen peroxide solution, and (c) the remainder a 55°-35° Baune sulfuric acid.
Claim 6
Dependent Claim
47 words
A stripping composition for use in reverse current stripping of plated metal substrates, comprising: (a) 6-38 parts by volume of a 20-25% aqueous chromic acid solution, (b) 2-8 parts by volume of a 35% aqueous hydrogen peroxide solution, and (c) the remainder a 55°-35° Baune sulfuric 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) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |