Water repellent coating film, method and apparatus for manufacturing the same, and water repellent coating material composition

• US 6,042,948 A
• Filed: 01/31/1997
• Issued: 03/28/2000
• Est. Priority Date: 02/01/1996
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ogawa, Kazufumi, Takebe, Yasuo, Mino, Norihisa
• Primary Examiner(s): Moore, Margaret G.
• Application Number:
  US08/792,133
• Time in Patent Office: 1,152 Days
• Field of Search: 428/447, 428/377, 428/405, 428/457, 428/704, 106/287.16, 106/287.19, 106/287.13
• US Class Current: 428/447
• CPC Class Codes: B05D 1/185 applying monomolecular layers B05D1/204 takes precedence
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: F28F 17/005 Means for draining condensates from heat exchangers, e.g. from evaporators F28B9/08 takes precedence
• CPC Class Codes: F28F 2245/02 hydrophilic
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]
• CPC Class Codes: Y10T 428/2995 Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

By forming a film that comprises a microcrystalline polymer having at least a fluorocarbon group and has a rough surface on a surface of a base material, super-water-repellency is provided, the dew condensation water of an air conditioner, for example, can be easily removed, and the freezing of the fin of the heat exchanger can be prevented. A fin that is made of aluminium is coated with a solution for forming a coating film, in which CF₃ (CF₂)₇ --(CH₂)₂ --SiCl₃ is diluted with nonaqueous cyclohexamethyl trisiloxane at a concentration of 10 vol. % for preparation, to a thickness of 1 to 10 μm by a brush, and then the cyclohexamethyl trisiloxane is vaporized in an atmosphere having a relative humidity of about 75% at room temperature. CF₃ (CF₂)₇ --(CH₂)₂ --SiCl₃ that remained on the fin is rapidly hydrolyzed with the moisture in the atmosphere, and the moisture in air and a --SiCl₃ group dehydrochlorinated to form a microcrystalline polymer on the fin. As a result, a coating film having a surface roughness in the range of 1 to 40 μm and a contact angle of about 171° to water can be formed.

Claims

1. A water repellent coating film comprising a polymer comprising a fluorocarbon group formed on a surface of a substrate, wherein the polymer of the film is a microcrystalline polymer and has a rough surface, and at least some of the molecules forming the film are covalently bonded to the surface of the substrate.

2. The water repellent coating film according to claim 1, wherein the microcrystalline polymer comprises a fluorocarbon group and is crosslinked by at least one bond selected from the group consisting of a siloxane (--SiO--) bond and a titanium-oxygen (--TiO--) bond.

3. The water repellent coating film according to claim 1, wherein the film further comprises a core comprising at least one material selected from the group consisting of a fine particle and a whisker.

4. The water repellent coating film according to claim 3, wherein the microcrystalline polymer having a fluorocarbon group is crosslinked by at least one bond selected from the group consisting of a siloxane (--SiO--) bond and a titanium-oxygen (--TiO--) bond and is chemically bonded to the core.

5. The water repellent coating film according to claim 2, wherein the microcrystalline polymer having a fluorocarbon group that is crosslinked by at least one bond selected from the group consisting of a siloxane bond and a titanium-oxygen (--TiO--) bond is formed by a hydrolysis reaction.

6. The water repellent coating film according to claim 1, wherein the roughness of the surface is in the range of 0.1 to 100 μ

m.

7. The water repellent coating film according to claim 1, wherein the roughness of the film is in the range of 0.1 to 100 μ

m.

8. The water repellent coating film according to claim 1, wherein the film is cloudy with a color of white or is opaque.

9. The water repellent coating film according to claim 1, wherein the water repellent coating film is formed on a surface of a fin of a heat exchanger.

10. The water repellent coating film according to claim 9, wherein a surface of a base material of the fin is roughened.

11. The water repellent coating film according to claim 10, wherein the roughness of the surface of the base material is in the range of 0.1 to 50 μ

m.

12. The water repellent coating film according to claim 9, wherein the fin is incorporated in a heat exchange part of an air conditioner.