Merchandisers having anti-fog coatings and methods for making the same

• US 20060127586A1
• Filed: 02/02/2006
• Published: 06/15/2006
• Est. Priority Date: 05/02/2002
• Status: Abandoned Application

• Current Assignee: Hussmann Corporation (Panasonic Holdings Corporation)
• Original Assignee: Hussmann Corporation (Panasonic Holdings Corporation)
• Inventors: Madireddi, Sesha C., Raglin, Benjamin W., Bernheim, Edward A., Roche, John R.
• Application Number:
  US11/346,129
• Publication Number:
  US 20060127586A1
• Time in Patent Office: Days
• US Class Current: 427/372.200
• CPC Class Codes: A47F 3/0434 Glass or transparent panels
• CPC Class Codes: C03C 17/322 Polyurethanes or polyisocyanates
• CPC Class Codes: C08G 18/283 Compounds containing ether groups, e.g. oxyalkylated monohydroxy compounds
• CPC Class Codes: C08G 18/4277 Caprolactone and/or substituted caprolactone
• CPC Class Codes: C08G 18/4833 Polyethers containing oxyethylene units
• CPC Class Codes: C08G 18/8074 Lactams
• CPC Class Codes: C08G 18/8093 Compounds containing active methylene groups
• CPC Class Codes: C08G 2290/00 Compositions for creating anti-fogging
• CPC Class Codes: C09D 175/04 Polyurethanes

Abstract

A variety of refrigerators and merchandisers having glass or plastic substrates that are substantially fog-resistant are provided. For example, refrigerator doors having a substantially transparent substrate including an anti-fog coating on at least a portion thereof are provided. The portion of the substrate may substantially not fog when the portion has an initial surface temperature and is then exposed to a moist air ambient with a dewpoint temperature equal to or greater than the surface temperature for a period of time. The surface temperature may be less than about 0° C. and the period of time may be greater than about 6 seconds.

Claims

1. A method of manufacturing a refrigerator door having a substantially transparent substrate, the method comprising the acts of:

mixing a blocked hexamethylene diisocyanate and a polyol to form a mixture;

applying the mixture to at least a portion of the substantially transparent substrate; and

curing the mixture,

wherein the substrate is part of a refrigerator door or is used to manufacture a refrigerator door.

2. The method of claim 1, wherein the diisocyanate is blocked by 3,5-dimethylpyrazole.

3. The method of claim 1, wherein the polyol comprises polyalkylene glycols.

4. The method of claim 1, wherein the blocked hexamethylene diisocyanate comprises 3,5-dimethylpyrazole blocked biuret of hexamethylene diisocyanante.

5. The method of claim 1, wherein the blocked hexamethylene diisocyanate comprises 3,5-dimethylpyrazole blocked biuret of hexamethylene diisocyanante and the polyol comprises a block polymer of polyethylene glycol and polypropylene glycol.

6. The method of claim 5, wherein the mixture comprises about 15% to about 90% by weight 3,5-dimethylpyrazole blocked biuret of hexamethylene diisocyanate and about 10.0% to about 85.0% by weight block polymer of polyethylene glycol and polypropylene glycol.

7. The mixture of claim 6 further comprising dibutyl tin dilaurate in an amount not greater than about 2% by weight.

8. The method of claim 1, wherein the mixture further comprises dibutyl tin dilaurate.

9. The method of claim 8, wherein the mixture further comprises diacetone alcohol.

10. The method of claim 1, wherein the mixture comprises about 15% to about 90% by weight blocked hexamethylene diisocyanate and about 10.0% to about 85.0% by weight polyol.

11. The method of claim 10 further comprising dibutyl tin dilaurate in an amount not greater than about 2% by weight.

12. The method of claim 1, wherein the mixture is applied to a transparent substrate having a low-emissivity surface or a low-emissivity coating thereon.

13. The method of claim 12, wherein the low-emissivity surface or coating does not emit radiation between about 0.7 microns and about 2.7 microns.

14. The method of claim 1, wherein the cured mixture forms a coating comprising a hydrophobic surface having a surface tension.

15. The method of claim 14, wherein the surface tension of the hydrophobic surface is less than about 58 dynes/cm.

16. The method of claim 14, wherein the surface tension of the hydrophobic surface is less than about 39 dynes/cm.

17. The method of claim 14, wherein the surface tension of the hydrophobic surface is less than about 26 dynes/cm.

18. The method of claim 1, wherein the portion of the substrate does not substantially fog when the portion has an initial surface temperature and is then exposed to a moist air ambient with a dewpoint temperature equal to or greater than the surface temperature for a period of time, wherein the surface temperature is less than about 0°

C. and the period of time is greater than about 6 seconds.

19. The method of claim 18, wherein the period of time is greater than about five minutes.

20. The method of claim 1, wherein the portion of the substrate does not substantially fog when the portion has an initial surface temperature and is then exposed to a moist air ambient with a dewpoint temperature equal to or greater than the surface temperature for a period of time, wherein the surface temperature is less than about −

18°

C. and the period of time is greater than about 6 seconds.

21. The method of claim 20, wherein the period of time is greater than about five minutes.