Super water-repellent coating material, and super water-repellent coating film using the same

• US 6,068,911 A
• Filed: 04/17/1997
• Issued: 05/30/2000
• Est. Priority Date: 04/18/1996
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shouji, Mitsuyoshi, Kawashima, Ken'ichi, Ito, Yutaka, Hamada, Tomoyuki
• Primary Examiner(s): Le, Hoa T.
• Application Number:
  US08/838,258
• Time in Patent Office: 1,139 Days
• Field of Search: 428/323, 428/421, 428/422, 428/143, 428/149, 428/212, 428/219, 428/220, 428/340, 428/457, 428/461, 428/463
• US Class Current: 428/143
• CPC Class Codes: B05D 5/083 involving the use of fluoropolymers
• CPC Class Codes: B05D 7/52 Two layers
• CPC Class Codes: F28F 13/18 by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
• CPC Class Codes: F28F 2245/04 hydrophobic
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/27 Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31544 Addition polymer is perhalogenated

Abstract

A super water-repellent coating film is formed of a super water-repellent coating material comprising an organic coating material composed of organic polymer, a filler mixture composed of plural kinds of fillers of at least 5 nm in average particle diameter, which is dispersed in the coating material, and a perfluoropolyoxyalkyl group compound. Because the surface of various solid bodies can be made super water-repellent by a simple process using this water-repellent coating material, the coating film can be utilized in various fields, such as preventing snow covering, frosting, ice coating, water adhering, and other applications.

Claims

1. A solid body having a super water-repellent coating film comprising an organic coating film formed on a surface of the solid body, surface roughness of said surface being at least 200 nm, wherein

said organic coating film comprises:

a first layer having fractal dimension of at least 2.4, which is obtained by coating said surface of the solid body with a coating material containing an organic polymer and having dispersed therein at least two kinds of fillers, and

a second layer composed of a perfluoropolyoxyalkyl group compound or a perfluoropolyoxyalkylene group compound on the surface of said first layer.

3. A solid body as claimed in either of claims 1 and 2, wherein

said filler has an average particle diameter of at least 5 nm.

4. A solid body as claimed in claim 3, wherein the at least two kinds of fillers have different diameters from each other.

5. A solid body as claimed in claim 3, wherein said fillers have a specific surface area of at least 100 m² /g.

6. A solid body as claimed in claim 3, wherein said solid body is an evaporator fin, having a fin member and said coating film covering said fin member.

7. A solid body as claimed in claim 3, wherein said solid body is a refrigerating air conditioner provided with an evaporator fin, said evaporator fin having a fin member and said coating film covering said fin member.

8. A solid body as claimed in claim 3, wherein said solid body is an electric wire coated with said coating film.

9. A method for forming the solid body claimed in claim 3, comprising the steps of:

dispersing a filler mixture composed of at least two kinds of fillers into a solution containing perfluoropolyoxyalkyl group compound or perfluoropolyoxyalkylene group compound, and

applying said dispersed solution onto the solid body.

10. A solid body as claimed in either of claims 1 and 2, wherein

said perfluoropolyoxyalkyl group compound or said perfluoropolyoxyalkylene group compound is expressed by the following general chemical formula (I)

11. A solid body as claimed in claim 10, wherein

said perfluoropolyoxyalkyl group contains the oxyalkylene repeating unit expressed by the following formulas (II), (III), or (Iv), individually or as a mixture of these units;

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12. A solid body as claimed in claim 11, wherein said solid body is an evaporator fin, having a fin member and said coating film covering said fin member.

13. A solid body as claimed in claim 11, wherein said solid body is a refrigerating air conditioner provided with an evaporator fin, said evaporator fin having a fin member and said coating film covering said fin member.

14. A solid body as claimed in claim 11, wherein said solid body is an electric wire coated with said coating film.

15. A method for forming the solid body claimed in claim 11, comprising the steps of:

dispersing a filler mixture composed of at least two kinds of fillers into a solution containing perfluoropolyoxyalkyl group compound or perfluoropolyoxyalkylene group compound, and

applying said dispersed solution onto the solid body.

16. A solid body as claimed in claim 10, wherein said solid body is an evaporator fin, having a fin member and said coating film covering said fin member.

17. A solid body as claimed in claim 10, wherein said solid body is a refrigerating air conditioner provided with an evaporator fin, said evaporator fin having a fin member and said coating film covering said fin member.

18. A solid body as claimed in claim 10, wherein said solid body is an electric wire coated with said coating film.

19. A method for forming the solid body claimed in claim 10, comprising the steps of:

dispersing a filler mixture composed of at least two kinds of fillers into a solution containing perfluoropolyoxyalkyl group compound or perfluoropolyoxyalkylene group compound, and

applying said dispersed solution onto the solid body.

20. A solid body as claimed in either of claims 1 and 2, wherein the at least two kinds of fillers have different diameters from each other.

21. A solid body as claimed in either of claims 1 and 2, wherein said fillers have a specific surface area of at least 100 m² /g.

22. A solid body as claimed in either of claims 1 and 2, wherein said solid body is an evaporator fin, having a fin member and said coating film covering said fin member.

23. A solid body as claimed in either of claims 1 and 2, wherein said solid body is a refrigerating air conditioner provided with an evaporator fin, said evaporator fin having a fin member and said coating film covering said fin member.

24. A solid body as claimed in either of claims 1 and 2, wherein said solid body is an electric wire coated with said coating film.

25. A method for forming the solid body claimed in either of claims 1 and 2, comprising the steps of:

dispersing a filler mixture composed of at least two kinds of fillers into a solution containing perfluoropolyoxyalkyl group compound or perfluoropolyoxyalkylene group compound, and

applying said dispersed solution onto the solid body.

2. A solid body having a super water-repellent coating film comprising an organic coating film formed on a surface of the solid body, surface roughness of said surface being at least 200 nm, wherein

said organic coating film comprises:

a first layer having fractal dimension of at least 2.4, which is obtained by coating said surface of the solid body with a coating material containing an organic polymer and having dispersed therein at least two kinds of fillers, and a surface multiple coefficient, which is a coefficient giving the ratio of actual area of a rough surface to the projected area, in the range of at least 2.0, and

a second layer composed of a perfluoropolyoxyalkyl group compound or a perfluoropolyoxyalkylene group compound on the surface of said first layer.