Non-stick polymer coated aluminum foil

• US 6,544,658 B2
• Filed: 05/14/2001
• Issued: 04/08/2003
• Est. Priority Date: 05/24/2000
• Status: Expired due to Term

• Current Assignee: Reynolds Consumer Products Incorporated
• Original Assignee: Reynolds Metals Company (Howmet Aerospace, Inc.)
• Inventors: Robbins, Bruce
• Primary Examiner(s): Dawson, Robert
• Assistant Examiner(s): Zimmer, Marc S
• Application Number:
  US09/853,636
• Publication Number:
  US 20020001727A1
• Time in Patent Office: 694 Days
• Field of Search: 427/374.3, 427/379, 427/388.1, 427/388.2, 428/458, 428/482
• US Class Current: 428/458
• CPC Class Codes: B05D 3/0209 Multistage baking
• CPC Class Codes: B05D 5/08 to obtain an anti-friction or anti-adhesive surface rendering particulate materials free-flowing in general, e.g. making them hydrophobic B01J2/30
• CPC Class Codes: B05D 7/14 to metal, e.g. car bodies involving a chemical reaction between the metal and the coating C23
• CPC Class Codes: Y10T 428/31681 Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]

Abstract

A non-stick polymer coated aluminum foil and method of making it. The method of making a non-stick polymer coated aluminum foil comprising applying a curable polymer coating composition on at least a portion of one side of an aluminum foil and partially curing the coating composition to allow handling and further processing of the coated aluminum foil without blocking of the coating composition. The curing of the coating composition is completed by heating the coated aluminum foil in bulk. The polymer coating composition may include a cross-linkable polyester.

Claims

1. A method of making a coated metal article comprising:

applying a curable polyester-based coating composition on at least a portion of one side of a metal article to form a coated metal article including a coating; and

partially curing the coating in a first heating step by heating the coated metal article at a sufficiently high temperature to allow completion of the curing of the coated metal article in bulk without blocking.

2. The method of claim 1, wherein the metal article is an aluminum foil.

3. The method of claim 2, wherein said first heating step further comprises passing the coated aluminum foil through an oven in a continuous process at a throughput rate and at an oven temperature sufficient to allow the temperature of the metal surface of the aluminum foil to reach a temperature of at least about 300°

F. as the coated aluminum foil exits the oven.

4. The method of claim 2, further comprising the steps of winding the partially cured coated aluminum foil in a coil;

cooling the aluminum foil in coil form; and

a second heating step comprising heating the aluminum foil in coil form to a temperature and for a time sufficient to complete the curing of the coating composition.

5. The method of claim 2, wherein said coating composition is applied on said aluminum foil in an amount of from about 0.025 lbs. to about 0.2 lbs. per 3,000 square feet.

6. The method of claim 4, wherein said cooling of the aluminum foil in coil form is done gradually.

7. The method of claim 2, wherein said coating composition comprises a cross-linkable polyester resin, a curing agent, and a solvent.

8. The method of claim 2, wherein said first heating step comprises heating the aluminum foil in web form to a temperature of from about 300°

F. to about 350°

F.

9. The method of claim 4, wherein said second heating step comprises heating the aluminum foil in coil form to a temperature of from about 350°

F. to about 425°

F.

10. The method of claim 7, wherein said coating composition further comprises a release agent.

15. The method of claim 10, wherein said coating composition comprises a cross-linkable polyester resin, a curing agent, and a solvent.

16. A non-stick, polymer coated aluminum foil formed according to the method of claim 4.

11. A method of making a non-stick, coated aluminum foil comprising:

applying a curable polyester-based coating composition on at least a portion of one side of an aluminum foil;

partially curing the coating composition sufficiently to allow winding the aluminum foil in coil form without blocking of the coating composition; and

completing the curing of the coating composition by heating the aluminum foil in coil form.

12. The method of claim 11, wherein completing the curing comprises heating the aluminum foil in coil form in an oven without blocking of the aluminum coil comprising the coating composition.

13. The method of claim 11, wherein completing the curing comprises heating the aluminum foil in coil form to a temperature of from about 350°

F. to about 425°

F., for a time of from about 1 hour to about 5 hours.

14. The method of claim 11, wherein completing the curing comprises heating the aluminum foil in coil form to a temperature of at least about 350°

F. for a time of at least about 5 minutes.

17. A non-stick, polymer coated aluminum foil formed according to the method of claim 11.

18. A non-stick polymer coated metal article comprising:

a metal article; and

a non-stick, polyester based coating bonded on at least a portion of one side of the metal article, wherein the coating is formed by;

applying a non-stick, polyester-based coating on at least a portion of one side of the metal article;

partially curing the coating in a first heating step by heating the coated metal article at a sufficiently high temperature to allow completion of the curing of the coated metal article in bulk without blocking;

gradually cooling and collecting the partially cured article in a bulk form; and

heating the metal article in bulk form to a temperature and for a time sufficient to complete the cure of the coating composition.

19. The coated metal article of claim 18, wherein said metal article is a foil.

20. The coated metal article of claim 18, wherein said metal article is made of a metal comprising aluminum, copper, silver, chromium or alloys thereof.

21. The article of claim 18, wherein collecting the partially cured coated metal article in a bulk form comprises winding the partially cured coated metal article.