Methods of making highly durable superhydrophobic, oleophobic and anti-icing coatings

• US 9,279,073 B2
• Filed: 06/30/2014
• Issued: 03/08/2016
• Est. Priority Date: 10/07/2008
• Status: Active Grant

• Current Assignee: ADT Technology LLC
• Original Assignee: Ross Technology Corporation
• Inventors: Harsh, Philip, Hurley, Michael, Jones, Andrew K., Ross, Russell, Sikka, Vinod K., Zielke, Donald, Bleecher, Douglas
• Primary Examiner(s): FLETCHER III, WILLIAM P
• Application Number:
  US14/320,358
• Publication Number:
  US 20150030779A1
• Time in Patent Office: 617 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C03C 15/00 Surface treatment of glass, not in the form of fibres or filaments, by etching etching or surface-brightening compositions, in general C09K13/00
• CPC Class Codes: C03C 17/30 with silicon-containing compounds
• CPC Class Codes: C03C 19/00 Surface treatment of glass, not in the form of fibres or filaments, by mechanical means sand-blasting, grinding, or polishing glass B24
• CPC Class Codes: C03C 2217/20 Materials for coating a single layer on glass
• CPC Class Codes: C03C 2217/76 Hydrophobic and oleophobic coatings
• CPC Class Codes: C03C 2218/11 from solutions or suspensions
• CPC Class Codes: C03C 2218/17 from a solid phase
• CPC Class Codes: C03C 2218/31 Pre-treatment
• CPC Class Codes: C03C 2218/34 Masking
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08K 3/40 Glass
• CPC Class Codes: C08K 9/08 Ingredients agglomerated by treatment with a binding agent
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/67 Particle size smaller than 100 nm
• CPC Class Codes: C09D 7/68 Particle size between 100-1000 nm
• CPC Class Codes: C09D 7/69 Particle size larger than 1000 nm
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• 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
• CPC Class Codes: C23C 4/10 Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
• CPC Class Codes: C23C 4/12 : characterised by the method of spraying
• CPC Class Codes: C23C 4/126 : Detonation spraying
• CPC Class Codes: C23C 4/129 : Flame spraying
• CPC Class Codes: D06M 11/79 : with silicon dioxide, silicic acids or their salts
• CPC Class Codes: D06M 15/564 : Polyureas, polyurethanes or other polymers having ureide or urethane links; Precondensation products forming them
• CPC Class Codes: D06M 2200/11 : Oleophobic properties
• CPC Class Codes: D06M 2200/12 : Hydrophobic properties
• CPC Class Codes: D06M 23/08 : Processes in which the treating agent is applied in powder or granular form adhesives for multi-layer textile fabrics D06M17/00
• CPC Class Codes: F25D 23/00 : General constructional features F25D21/00 takes precedence
• CPC Class Codes: F25D 2325/022 : Shelves made of glass or ceramic
• CPC Class Codes: F25D 2400/22 : Cleaning means for refrigerating devices
• CPC Class Codes: F25D 25/02 : by shelves
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• 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 442/2172 : Also specified as oil repellent

Abstract

Disclosed are methods of preparing durable hydrophobic, oleophobic, and anti-icing coatings on a substrate comprising the application of a binder containing particles to the substrate and the application of hydrophobic and oleophobic particles to the binder. In the resulting coating, the particles applied with the binder are primarily distributed within and coated by the binder and the hydrophobic/oleophobic particles are distributed on or at the exposed surface where they can interact with liquids.

Claims

1. A method of preparing a hydrophobic coating on a substrate comprising:

a) applying to said substrate a coating composition, comprising i) a binder, ii) first particles having a size of about 30 microns to about 225 microns, and iii) a solvent, to provide a base coating; and

b) applying to said base coating a composition comprising second particles, wherein, prior to the application of the second particles to the base coating,

i) the second particles have been modified with hexamethyldisilazane,

ii) the second particles comprise covalently bound polydimethylsiloxane, or

iii) the second particles comprise one or more covalently bound moieties independently selected from the group consisting of alkyl, haloalkyl, and perfluoroalkyl moieties, which one or more moieties are covalently bound to said second particles by reaction of particles with a silanizing agent of formula (I), said silanizing agent of formula (I) having the structure;

R_4-nSi—

X_n 

 

(I)

where n is an integer from 1 to 3;

each R is independently selected from

(i) C_{1 to 20} alkyl optionally substituted with one or more fluorine atoms;

or

(ii) —

Z—

((CF₂)_q(CF₃))_r, wherein Z is a C_1-12 divalent alkane radical or a C_2-12 divalent alkene or alkyne radical, q is an integer from 1 to 12, and r is an integer from 1-4;

each X is independently selected from the group consisting of —

H, —

Cl, —

I, —

Br, —

OH, —

OR², NHR³, and —

N(R³)₂;

each R² is an independently selected C_{1 to 4} alkyl or haloalkyl group; and

each R³ is an independently selected H, C_{1 to 4} alkyl or haloalkyl group;

wherein the hydrophobic coating has a contact angle with water that is greater than about 120°

at a temperature of 18°

C. to 23°

C.;

wherein the hydrophobic coating has a surface in contact with the substrate and an exposed surface comprising the binder that is not in contact with the substrate, the exposed surface having an arithmetical mean roughness from about 0.2 microns to about 20 microns, or a ten point mean roughness from about 1 micron to about 100 microns;

wherein, in the resulting hydrophobic coating, the first particles are primarily distributed within and coated with the binder and the second particles are primarily distributed on the exposed surface; and

wherein the hydrophobic coating has a greater number of second particles on the exposed surface than on the surface in contact with the substrate.

2. The method of claim 1, wherein the binder comprises a polyurethane, lacquer, fluoropolymer, epoxy or thermoplastic powder coating.

3. The method of claim 2, wherein the binder comprises a polyurethane.

4. The method of claim 2, wherein the binder comprises a lacquer.

5. The method of claim 2, wherein the binder comprises a fluoropolymer or an epoxy.

6. The method of claim 1, wherein said first particles comprise a material selected from the group consisting of:

cellulose, glass, metal oxides, metalloid oxides, plastics, carbides, nitrides, borides, spinels, diamond, fibers, and thermoplastic.

7. The method of claim 1, wherein said second particles comprise:

a metal oxide, an oxide of a metalloid, a silicate, or a glass.

8. The method of claim 1, wherein said second particles comprise one or more alkyl, fluoroalkyl or perfluoroalkyl moieties that are covalently bound to the second particles directly or indirectly through one or more atoms bound to the second particles.

9. The method of claim 1, wherein, prior to the application of the second particles to the base coating, said second particles have been modified with an agent selected from the group consisting of:

(tridecafluoro-1,1,2,2-tetrahydrooctyl)silane;

(tridecafluoro-1,1,2,2-tetrahydrooctyl) trichlorosilane;

(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane;

(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane;

(heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethyl(dimethylamino)silane;

(heptadecafluoro-1,1,2,2-tetrahydrodecyl)tris(dimethylamino)silane;

n-octadecyltrimethoxysilane;

n-octyltriethoxysilane;

nonafluorohexyldimethyl(dimethylamino)silane; and

polydimethylsiloxane; and

wherein, following the modification, the second particles comprise at least one moiety selected from the group consisting of alkyl, haloalkyl, and perfluoroalkyl.

10. The method of claim 1, wherein the hydrophobic coating has an arithmetical mean roughness from about 0.2 microns to about 20 microns.

11. The method of claim 1, wherein said hydrophobic coating retains its hydrophobicity when subject to at least 200 abrasion cycles, as measured with a Taber Abrasion tester model 503 using CS-10 wheels and 250 g loads, wherein a surface is no longer considered to retain its hydrophobicity when more than half of the water droplets placed on the abraded surface are retained on the abraded surface when the abraded surface is inclined at an angle of 6°

.

12. The method of claim 1, wherein said hydrophobic coating retains its hydrophobicity when subject to at least 100 abrasion cycles, as measured with a Taber Abrasion tester model 503 using CS-10 wheels and 250 g loads, wherein a surface is no longer considered to retain its hydrophobicity when more than half of the water droplets placed on the abraded surface are retained on the abraded surface when the abraded surface is inclined at an angle of 6°

.

13. The method of claim 1, wherein the composition at step (b) further comprises a solvent.

14. The method of claim 1, wherein the second particles comprise silica or alumina.

15. The method of claim 1, wherein the hydrophobic coating has a contact angle with water that is greater than about 130°

at a temperature of 18°

C. to 23°

C.

16. The method of claim 1, wherein said second particles that comprise one or more covalently bound moieties independently selected from the group consisting of alkyl, haloalkyl, and perfluoroalkyl moieties are second particles that have been modified with a silanizing agent of formula (I):

R_4-nSi—

X_n 

 

(I)

where n is an integer from 1 to 3;

each R is an independently selected —

Z—

((CF₂)_q(CF₃))_r group, wherein Z is a C_1-12 divalent alkane, q is an integer from 1 to 12, and r is an integer from 1-4;

each X is independently selected from the group consisting of —

H, —

Cl, —

I, —

Br, —

OH, —

OR², —

NHR³, and —

N(R³)₂;

each R² is an independently selected C_{1 to 4} alkyl or haloalkyl group; and

each R³ is an independently selected H, C_{1 to 4} alkyl or haloalkyl group.

17. The method of claim 1, wherein said second particles have a size of about 1 nanometer to 25 microns.

18. The method of claim 1, wherein the binder comprises an acrylic lacquer.