ARTICLES HAVING DURABLE HYDROPHOBIC SURFACES

• US 20070298216A1
• Filed: 06/23/2006
• Published: 12/27/2007
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jing, Naiyong, Spurgeon, Kathryn M., Tiers, George Van Dyke, Jones, Vivian W., Kolb, Brant U., Cao, Chuntao, Dams, Rudolf J.
• Granted Patent: US 8,354,160 B2
• Time in Patent Office: Days
• US Class Current: 428/141
• CPC Class Codes: B05D 2601/20 used for non-pigmentation effect
• 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 7/04 to surfaces of films or sheets producing layered products by applying coatings of pasty or pulverulent plastics B29C41/00
• CPC Class Codes: C09D 5/00 Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced electrically insulating plastics, resins or waxes H01B3/30; Filling pastes
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/24405 Polymer or resin [e.g., natural or synthetic rubber, etc.]
• CPC Class Codes: Y10T 428/24413 Metal or metal compound
• CPC Class Codes: Y10T 428/24421 Silicon containing
• CPC Class Codes: Y10T 428/251 Mica
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/257 Iron oxide or aluminum oxide
• CPC Class Codes: Y10T 428/258 Alkali metal or alkaline earth metal or compound thereof
• CPC Class Codes: Y10T 428/259 Silicic material

Abstract

Method of forming a very hydrophobic, extremely hydrophobic or superhydrophobic surface comprising depositing a composition comprising hydrophobic microparticles, hydrophobic nanoparticles, or a mixture thereof and a binder in sufficient quantity to provide a hydrophobic or a superhydrophobic surface on a substrate having a micropatterned surface having raised portions, recessed portions or a combination thereof.

Claims

1. A method of forming a very hydrophobic or superhydrophobic surface comprising:

depositing a liquid composition comprising a binder and hydrophobic microparticles, hydrophobic nanoparticles, or a mixture thereof in sufficient quantity to provide a very hydrophobic or superhydrophobic surface on a substrate having a micropatterned surface comprising raised portions, recessed portions or a combination thereof; and

drying or otherwise hardening the liquid composition.

2. The method of claim 1, wherein the dried or hardened composition forms a discontinuous coating interrupted by projecting features of the micropatterned surface.

3. The method of claim 1, wherein the microparticles or nanoparticles comprise surface-modified particles comprising insoluble metal oxides or metal salts.

4. The method of claim 1, wherein the microparticles or nanoparticles comprise surface-modified particles comprising silicon oxide, aluminum oxide, calcium carbonate, titanium oxide or zirconium oxide.

5. The method of claim 1, wherein the microparticles and nanoparticles comprise silica particles.

6. The method of claim 1, wherein the microparticles or nanoparticles have been modified by contacting with a hydrolytically reactive silane bearing at least one hydrolyzable group, and catalyst for sufficient time to enhance the hydrophobicity of the particles.

7. The method of claim 1, wherein the raised portions of the micropatterned surface are regular repeating features about 5 μ

m to about 150 μ

m above the recessed or other portions of the surface.

8. The method of claim 1, wherein the micropatterned surface exhibits repeating projecting features having a pitch of about 10 μ

m to about 250 μ

m in length.

9. The method of claim 1, wherein the binder comprises a hydrocarbon polymer or a fluoropolymer.

10. The method of claim 9, wherein the fluoropolymer is selected from the group consisting of poly-1,1-difluoroethylene;

a copolymer of tetrafluoroethylene and hexafluoropropylene;

a terpolymer of hexafluoropropylene, tetrafluoroethylene, and ethylene; and

a terpolymer of tetrafluoroethylene, hexafluoropropylene and 1,1-difluorethylene.

11. The method of claim 1, wherein the substrate is selected from the group consisting of polyacrylates, polymethacrylates, polyesters, polypropylene, polyethylene, polystyrene, polycarbonates, polyimides, polyvinyl chloride, polyvinyl butyral, cellulose acetates and co-butyrates, fluoropolymers, and silicone rubbers.

12. The method of claim 11, wherein the substrate is selected from the group consisting of polyacrylates, polymethacrylates, polyesters, fluoropolymers, and a fluorinated acrylic polymer.

13. An article comprising a substrate having a micropatterned surface comprising raised portions, recessed portions or a combination thereof, and a coating composition on the substrate located at least on the portions between the raised portions or in the recessed portions and comprising a binder and hydrophobic microparticles, hydrophobic nanoparticles, or a mixture thereof;

in sufficient quantity to provide a very hydrophobic or superhydrophobic surface.

14. The article of claim 13, wherein the coating composition forms a discontinuous layer interrupted by raised portions of the micropatterned surface.

15. The article of claim 13, wherein the microparticles or nanoparticles comprise a material selected from silicon oxide, aluminum oxide, calcium carbonate, titanium oxide, zirconium oxide, and mixtures thereof.

16. The article of claim 15, wherein the microparticles or nanoparticles have been modified by contacting with a hydrolytically reactive silane bearing at least one hydrolyzable group, and catalyst for sufficient time to enhance the hydrophobicity of the particles.

17. The article of claim 16, wherein the microparticles and nanoparticles comprise silica particles.

18. The article method of claim 13, wherein the material of the substrate is selected from the group consisting of polyacrylates, polymethacrylates, polyesters, polypropylene, polyethylene, polystyrene, polyvinyl butyral, polycarbonates, polyimides, polyvinyl chloride, cellulose acetates and co-butyrates, fluoropolymers, and silicone rubbers.

19. The article of claim 18, wherein the substrate is selected from the group consisting of polyacrylates, polymethacrylates, polyesters, fluoropolymers, and a fluorinated acrylic polymer.

20. The article of claim 13, wherein the binder comprises a hydrocarbon polymer or a fluoropolymer.

21. The article of claim 20, wherein the fluoropolymer is selected from the group consisting of poly-1,1-difluoroethylene;

copolymers of tetrafluoroethylene and hexafluoropropylene;

terpolymers of hexafluoropropylene, tetrafluoroethylene, and ethylene; and

terpolymers of tetrafluoroethylene, hexafluoropropylene and 1,1-difluorethylene.