US4477290A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cleaning and etching process for aluminum containers
Assignee: Arkema Inc
•
Filing: 1983-01-10
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Granted: 1984-10-16
•
Expires: 2003-01-10
Abstract
Abstract Drawn and ironed (D & I) aluminum can bodies are prepared for conversion coating by cleaning and etching using a spray of a dilute aqueous solution of caustic and chelating agent at temperatures of up to about 130° F. The dilute aqueous alkaline solution consists essentially of from about 6 to 12 grams per liter of an alkali metal hydroxide and from about 3 to 6 grams per liter of a chelating agent. The cleaning and etching can be accomplished in a single step without smut formation.
Inventors
- 👤 James W. Carroll
- 👤 James E. Comstock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:51
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/14; C23G1/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
71 words
A process for cleaning and etching the surface of an aluminum container comprising spraying the surface with a dilute aqueous alkaline solution consisting essentially of from about 6 to 12 grams per liter of an alkali metal hydroxide and from about 3 to 6 grams per liter of a chelating agent at an elevated temperature from about 80° to 130° F. so as to form a clean, bright surface without desmutting.
Claim 2
Dependent Claim
71 words
A process for cleaning and etching the surface of an aluminum container comprising spraying the surface with a dilute aqueous alkaline solution consisting essentially of from about 6 to 12 grams per liter of an alkali metal hydroxide and from about 3 to 6 grams per liter of a chelating agent at an elevated temperature from about 80° to 130° F. so as to form a clean, bright surface without desmutting.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the temperature of the solution ranges of from about 100°-120° F.
Claim 4
Dependent Claim
31 words
The process of claim 1 wherein the surface is sprayed with a solution for from about 30 to 60 seconds at a spray pressure of from about 10 to 40 psi.
Claim 5
Dependent Claim
16 words
The process of claim 1 including the step of pre-cleaning the container before cleaning and etching.
Claim 6
Dependent Claim
19 words
The process of claim 4 wherein the container is pre-cleaned in a spray of an uninhibited alkaline pre-cleaning bath.
Claim 7
Dependent Claim
30 words
The process of claim 5 wherein the alkaline pre-cleaning bath is an aqueous solution including an alkali metal hydroxide at concentration of from about 0.1 to 3 grams per liter.
Claim 8
Dependent Claim
48 words
The process of claim 5 wherein the alkaline pre-cleaning bath includes from about 0.6 to 2.0 grams per liter of tetra potassium pyrophosphate, from about 0.5 to 1.8 grams per liter of sodium gluconate and from about 0.5 to 1.8 grams per liter of soda ash in water.
Claim 9
Dependent Claim
19 words
The process of claim 1 including the steps of forming a conversion coating on the cleaned and etched surface.
Claim 10
Dependent Claim
18 words
The process of claim 1 wherein the chelating agent is selected from gluconic acid, glucoheptoic acid, and sorbitol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-16 | 1988-04-16 | 1988-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-16 | 1992-04-16 | 1992-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-16 | 1996-04-16 | 1996-10-16 | $7700.00 | Window Closed / Lapsed |