US4554049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective nickel stripping compositions and method of stripping
Assignee: MacDermid Enthone Inc
•
Filing: 1984-06-07
•
Granted: 1985-11-19
•
Expires: 2004-06-07
Abstract
Abstract Stripping solutions comprising hydrogen peroxide and sulfamic acid in correlated amounts are effective for the rapid and selective removal of nickel from mild steel surfaces and nickel, nickel alloy and nickel reaction products from alloy substrates. The compositions contain sulfamate, nitrate and chloride and peroxide ions and, preferably, an iron complexing agent such as ethylene diamine tetraacetic acid.
Inventors
- 👤 Edwin W. Bastenbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:23
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/44
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
81 words
An aqueous solution for selectively stripping electrolytic nickel and low phosphorous electroless nickel from a ferrous metal substrate comprising, in grams/liter: (a) Sulfamate ions (calculated as OSO 2 NH 2 ) in an amount about 25 to saturation; (b) Nitrate ions in an amount about 1 to 25; (c) Chloride ions in an amount about 0.1 to 8; (d) Hydrogen peroxide in an amount about 30 to 250; and (e) An iron complexing agent in an amount about 2 to 60.
Claim 2
Dependent Claim
81 words
An aqueous solution for selectively stripping electrolytic nickel and low phosphorous electroless nickel from a ferrous metal substrate comprising, in grams/liter: (a) Sulfamate ions (calculated as OSO 2 NH 2 ) in an amount about 25 to saturation; (b) Nitrate ions in an amount about 1 to 25; (c) Chloride ions in an amount about 0.1 to 8; (d) Hydrogen peroxide in an amount about 30 to 250; and (e) An iron complexing agent in an amount about 2 to 60.
Claim 3
Dependent Claim
69 words
The solution of claim 1 wherein the constituents are present in the following amounts, in grams/liter: (a) Sulfamic acid in an amount about 45 to 90; (b) Nitrate ions in an amount about 3 to 17; (c) Chloride ions in an amount about 0.5 to 4; (d) Hydrogen peroxide in an amount about 75 to 150; and (e) An iron complexing agent in an amount about 2 to 60.
Claim 4
Dependent Claim
69 words
The solution of claim 2 wherein the constituents are present in the following amounts, in grams/liter; (a) Sulfamic acid in an amount about 55 to 75; (b) Nitrate ions in an amount about 7 to 15; (c) Chloride ions in an amount about 1 to 3; (d) Hydrogen peroxide in an amount about 100 to 150; and (e) An iron complexing agent in an amount about 2 to 60.
Claim 5
Dependent Claim
15 words
The solution of claim 1 wherein the source of the sulfamate ions is sulfamic acid.
Claim 6
Dependent Claim
19 words
The solution of claim 4 wherein the source of the nitrate and chloride ions are the ammonium salts thereof.
Claim 7
Dependent Claim
15 words
The solution of claim 5 wherein the iron complexing agent is ethylene diamine tetraacetic acid.
Claim 8
Dependent Claim
15 words
The solution of claim 1 wherein the iron complexing agent is ethylene diamine tetraacetic acid.
Claim 9
Dependent Claim
48 words
A method for selectively stripping electrolytic nickel and low phosphorous electroless nickel from a ferrous metal substrate comprising: (a) contacting the deposit on the ferrous metal substrate with the solution of claim 1; and (b) continuing the contacting until the deposit is selectively removed from the substrate surface.
Claim 10
Dependent Claim
14 words
The method of claim 8 wherein the solution is the solution of claim 2.
Claim 11
Dependent Claim
14 words
The method of claim 8 wherein the solution is the solution of claim 6.
Claim 12
Dependent Claim
26 words
The method of claim 8 wherein the solution is at a temperature in the range of about 50° F. to about 120° F. during the contacting.
Claim 13
Dependent Claim
14 words
The method of claim 11 wherein the temperature range is below about 100° F.
Claim 14
Dependent Claim
42 words
A method for selectively stripping nickel sulfidation compounds from nickel-base alloy substrates comprising: (a) contacting the deposit on the alloy substrate with the solution of claim 1; and (b) continuing the contacting until the deposit is selectively removed from the substrate surface.
Claim 15
Dependent Claim
14 words
The method of claim 13 wherein the solution is the solution of claim 2.
Claim 16
Dependent Claim
14 words
The method of claim 13 wherein the solution is the solution of claim 6.
Claim 17
Dependent Claim
26 words
The method of claim 13 wherein the solution is at a temperature in the range of about 50° F. to about 120° F. during the contacting.
References Cited (Backward Citations)
US3367874A
Cited
US3399143A
Cited
US3801512A
Cited
JPS4923800A
Cited
US3856694A
Cited
US3931030A
Cited
JPS5518502A
Cited
US4244833A
Cited
US4302246A
Cited
JPS5782473A
Cited
JPS5798676A
Cited
JPS58174584A
Cited
US4459216A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |