Anti-fog refrigeration door and method of making the same

• US 8,613,179 B2
• Filed: 01/03/2011
• Issued: 12/24/2013
• Est. Priority Date: 09/20/2004
• Status: Expired due to Fees

• Current Assignee: AGC Flat Glass North America Incorporated (AGC, Inc.)
• Original Assignee: AGC Flat Glass North America Incorporated (AGC, Inc.)
• Inventors: Cording, Christopher R.
• Primary Examiner(s): GILBERT, WILLIAM V
• Application Number:
  US12/983,734
• Publication Number:
  US 20110165399A1
• Time in Patent Office: 1,086 Days
• Field of Search: 521/712, 521/713, 522/045, 522/046, 522/047.1, 527/861, 527/411, 428/447, 428/448, 428/429
• US Class Current: 52/741.1
• CPC Class Codes: A47F 3/0434 Glass or transparent panels
• CPC Class Codes: C03C 17/322 Polyurethanes or polyisocyanates
• CPC Class Codes: C03C 17/34 with at least two coatings having different compositions C03C17/44 takes precedence
• CPC Class Codes: C03C 2217/75 Hydrophilic and oleophilic coatings
• CPC Class Codes: C09D 175/04 Polyurethanes
• CPC Class Codes: C09K 3/18 for application to surfaces to minimize adherence of ice, mist or water thereto rendering particulate materials free flowing, in general, e.g. making them hydrophobic B01J2/30; Thawing or antifreeze materials for application to surfaces used in liquids for heat-transfer, heat-exchange or heat-storage or for the production of heat or cold other than by combustion, e.g. radiator liquids, C09K5/00

Abstract

The energy-free refrigeration door of the present application provides a way to control condensation when the door of a refrigeration unit is opened by providing thermal insulation to the door with glass panels which have a low emissivity coating. The door includes a door frame housing and an insulating glass unit comprising inner, middle and outer sheets of glass. A first sealant assembly disposed around the periphery of the inner and middle sheets of glass forms a first chamber between the inner and middle sheets of glass. A second sealant assembly disposed around the periphery of the middle and outer sheets of glass forms a second chamber between the middle and outer sheets of glass. A gas, such as krypton, air, or argon is held in the first and second chambers. The outer sheet of glass and inner sheet of glass each have an unexposed surface that faces the middle sheet of glass. A low emissivity coating is disposed on the unexposed surfaces of the inner and outer sheets of glass so that the glass door as a whole avoids formation of condensation on the outer surface of the outer sheet of the glass door, without the application of electricity to heat the door, while also providing the desired evaporation rate of condensation from the inner side of the inner sheet of the glass door. An anti-fog or anti-frost coating is included on a surface of one of the sheets of glass.

Claims

1. A method of forming an anti-fog or anti-frost coating on at least a portion of a substrate, the method comprising:

treating, prior to application of the anti-fog or anti-frost coating, at least a portion of the substrate with a solution consisting essentially of a first silane in water;

preparing a mixture of;

i) a first component comprising about 46% diacetone alcohol, about 4% N-methyl Pyrrolidone, about 4% t-butanol, about 8% Cyclohexane, about 6% 2,4-pentanedione, and about 2% Aromatic 150; and

ii) a second component comprising about 66% polyisocyanate, about 1% free monomeric isocyanates, about 11% xylene, about 11% n-butyl acetate, and about 11% toluene;

wherein the mixture ratio of the first component to the second component is about 100;

about 30-33;

adding a second silane to the mixture, wherein the second silane is different than the first silane;

applying the mixture to the substrate; and

curing the substrate.

2. The method of claim 1, wherein the mixture does not contain additional solvents.

3. The method of claim 1, wherein the mixture ratio of the first component to the second component is about 100:

about 30.

4. The method of claim 1, wherein the mixture is applied with a single coating step.

5. The method of claim 1, wherein the curing is achieved in a single curing cycle.

6. The method of claim 1, wherein the second silane comprises 3-glycidoxypropyl trimethoxysilane.

7. The method of claim 6, wherein the second silane is present in an amount of about 1% to about 8%.

8. The method of claim 7, wherein the second silane is present in an amount of about 6%.

9. The method of claim 1, wherein the first silane comprises amino alkyl silicone.

10. The method of claim 1, wherein the treating comprises preparing a rinse water mixture comprising about 1% or less of the first silane and applying said mixture to said portion of the substrate.

11. The method of claim 10, wherein the rinse water mixture comprises about 0.031% of the first silane.

12. The method of claim 1, wherein the coating is applied on top of a mirror.

13. The method of claim 1, wherein the coating is applied on top of a mirror designed for use in a sauna or steam room.

14. The method of claim 1, wherein the coating is applied on top of a transparent or semi-transparent substrate designed for use in a bathroom.

15. The method of claim 1, wherein the coating is applied on top of a window designed for use on the exterior of a building.

16. The method of claim 1, wherein the coating is applied on top of a mirror that is a part of an automobile.

17. The method of claim 1, wherein the substrate is cured using radiant energy.

18. The method of claim 1, wherein the mixture is applied with a curtain coater.

19. The method of claim 18, wherein the mixture is applied with a curtain coater that is modified to give the mixture a laminar flow as it is applied to the substrate.

20. The method of claim 19, wherein the mixture is applied with a weir-type curtain coater wherein the size of the weir lip is modified to avoid a semi-turbulent flow of the mixture as it is applied to the substrate.

21. The method of claim 1, whereby when applied to a substrate, the anti-fog or anti-frost coating results in a substrate and anti-fog or anti-frost coating structure that is substantially transparent to visible light.

22. The method of claim 1, whereby when applied to a reflective substrate, the anti-fog or anti-frost coating results in a reflective substrate and anti-fog or anti-frost coating structure that substantially reflects visible light.