US4294627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of tinplate surfaces
Assignee: Crown Packaging UK Ltd
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Filing: 1980-05-28
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Granted: 1981-10-13
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Expires: 2000-05-28
Abstract
Abstract A metal surface, particularly a tinplate surface of a can for canned food, is treated by contact with a solution containing a zirconium compound, particularly ammonium zirconium carbonate or zirconium acetate. An inorganic salt may also be present in the solution. The concentration of the zirconium compound, calculated as ZrO 2 , is in the range between 0.1 and 10% w/w. The surface is thereafter heated to a temperature in the range between 20° and 300° C. until it is dry. The surface may be cleaned prior to contact with the solution. In this way a coating is provided on the surface which improves the stain resistance of the surface.
Inventors
- 👤 Peter J. Heyes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:32
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/73; C23C22/74
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
82 words
A method of treating a tinplate surface comprising the steps: wetting said tinplate surface with a solution free of organic polymeric materials and consisting essentially of a solvent, and a zirconium compound selected from the group consisting of ammonium zirconium carbonate and zirconium acetate at a concentration, calculated as ZrO 2 , in the range between 0.1 and 10% w/w; and thereafter heating said tinplate surface to a temperature in the range between 20° and 300° C. until said surface is dry.
Claim 2
Independent Claim
82 words
A method of treating a tinplate surface comprising the steps: wetting said tinplate surface with a solution free of organic polymeric materials and consisting essentially of a solvent, and a zirconium compound selected from the group consisting of ammonium zirconium carbonate and zirconium acetate at a concentration, calculated as ZrO 2 , in the range between 0.1 and 10% w/w; and thereafter heating said tinplate surface to a temperature in the range between 20° and 300° C. until said surface is dry.
Claim 3
Dependent Claim
28 words
A method according to claim 1, wherein said solution also contains a minor amount of an inorganic salt selected from the group consisting of phosphates, silicates and borates.
Claim 4
Dependent Claim
17 words
A method according to claim 1 or claim 2, wherein said zirconium compound is ammonium zirconium carbonate.
Claim 5
Dependent Claim
16 words
A method according to claim 1 or claim 2, wherein said zirconium compound is zirconium acetate.
Claim 6
Dependent Claim
30 words
A method according to claim 1 or claim 2, wherein the concentration of said zirconium compound, calculated as ZrO 2 , is in the range between 0.2 and 2% w/w.
Claim 7
Dependent Claim
14 words
A method according to claim 1 or claim 2, wherein said solvent is water.
Claim 8
Dependent Claim
31 words
A method according to claim 1 or claim 2, further comprising cleaning said tinplate surface, so as to make it capable of wetting by said solvent, prior to said wetting step.
Claim 9
Dependent Claim
25 words
A method according to claim 7, wherein said cleaning step comprises passing a current between said tinplate surface and an auxiliary electrode in said solution.
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) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |