US3957553A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-chromated alkaline etching bath and etching process for aluminum
Assignee: Arkema Inc
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Filing: 1974-03-01
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Granted: 1976-05-18
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Expires: 1994-03-01
Abstract
Abstract Alkaline etching baths for aluminum are claimed in which oxidizing agents at low concentration replace chromates and fluorides in the control of galvanizing. Etching processes using these new baths are also disclosed and claimed.
Inventors
- 👤 Harold Vernon Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:26
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/14; C23G1/22; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/32; C23F1/36
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
46 words
The composition for etching aluminum and aluminum alloys comprised of an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter, at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter.
Claim 2
Dependent Claim
46 words
The composition for etching aluminum and aluminum alloys comprised of an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter, at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter.
Claim 3
Dependent Claim
34 words
The composition of claim 1 in which the oxidizing agent is selected from the group consisting of nitrites, persulfates, chlorites, peroxyphosphates, chlorates, perchlorates, peroxides, iodates, hypochlorites, perborates, periodates, bromates, nitrates, oxygen and chlorine dioxide.
Claim 4
Dependent Claim
20 words
The composition of claim 1 in which the alkali metal hydroxide concentration is from about 30 to about 75 grams/liter.
Claim 5
Dependent Claim
65 words
The process for etching aluminum and aluminum alloys comprising contacting the said aluminum with an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter, at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter for 1 to 15 minutes at a temperature within the range of 120° to 190°F.
Claim 6
Dependent Claim
65 words
The process for etching aluminum and aluminum alloys comprising contacting the said aluminum with an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter, at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter for 1 to 15 minutes at a temperature within the range of 120° to 190°F.
Claim 7
Dependent Claim
34 words
The process of claim 4 in which the oxidizing agent is selected from the group consisting of nitrites, persulfates, chlorites, peroxyphosphates, chlorates, perchlorates, peroxides, iodates, hypochlorites, perborates, periodates, bromates, nitrates, oxygen and chlorine dioxide.
Claim 8
Dependent Claim
20 words
The process of claim 4 in which the concentration of alkali metal hydroxide is about 30 to about 75 grams/liter.
Claim 9
Dependent Claim
69 words
The process for etching aluminum and aluminum alloys comprising immersing the said aluminum in an etching tank containing an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter for 1 to 15 minutes at a temperature within the range of 120° to 190°F.
Claim 10
Dependent Claim
69 words
The process for etching aluminum and aluminum alloys comprising immersing the said aluminum in an etching tank containing an aqueous solution of alkali metal hydroxide -- 15 to about 200 grams/liter at least one chelating agent -- 0.5 to about 15 grams/liter, and at least one oxidizing agent -- 0.0001 to about 1 gram/liter for 1 to 15 minutes at a temperature within the range of 120° to 190°F.
Claim 11
Dependent Claim
12 words
The process of claim 7 in which the oxidizing agent is oxygen.
Claim 12
Dependent Claim
25 words
The process of claim 8 in which the oxygen is generated by electrolysis of the etching solution using the aluminum being etched as the anode.
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) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |