Compositions and methods for fabricating durable, low-ice-adhesion coatings

Patent metadata

Field	Value
Publication number	US-10619057-B2
Application number	US-201715608975-A
Country	US
Kind code	B2
Filing date	May 30, 2017
Priority date	Aug 19, 2015
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

This invention provides durable, low-ice-adhesion coatings with excellent performance in terms of ice-adhesion reduction. Some variations provide a low-ice-adhesion coating comprising a microstructure with a first-material phase and a second-material phase that are microphase-separated on an average length scale of phase inhomogeneity from 1 micron to 100 microns. Some variations provide a low-ice-adhesion material comprising a continuous matrix containing a first component; and a plurality of discrete inclusions containing a second component, wherein the inclusions are dispersed within the matrix to form a phase-separated microstructure that is inhomogeneous on an average length scale from 1 micron to 100 microns, wherein one of the first component or the second component is a low-surface-energy polymer, and the other is a hygroscopic material. The coatings are characterized by an AMIL Centrifuge Ice Adhesion Reduction Factor up to 100 or more. These coatings are useful for aerospace surfaces and other applications.

First claim

What is claimed is:

1. A low-ice-adhesion coating comprising a microstructure characterized in that said microstructure contains at least a first-material phase and a second-material phase that is microphase-separated from said first-material phase on an average length scale of phase inhomogeneity from about 1 micron to about 100 microns, wherein said phase inhomogeneity of said microstructure results in low ice adhesion of said coating, characterized in that said coating, when subjected to an AMIL Centrifuge Ice Adhesion Test, generates an AMIL Centrifuge Ice Adhesion Reduction Factor of about 10 or more,
wherein said first-material phase and said second-material phase are covalently connected in a block copolymer that is a segmented copolymer composition comprising:
(a) one or more first soft segments selected from fluoropolymers having an average molecular weight from about 500 g/mol to about 10,000 g/mol, wherein said fluoropolymers are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated;
(b) one or more second soft segments selected from polyesters or polyethers, wherein said polyesters or polyethers are (α,ω)-hydroxyl-terminated and/or (α,ω)-amine-terminated;
(c) one or more isocyanate species, or a reacted form thereof, possessing an isocyanate functionality of 2 or greater; and
(d) one or more polyol or polyamine chain extenders or crosslinkers, or a reacted form thereof,
wherein the molar ratio of said second soft segments to said first soft segments is less than 2.0.

2. The low-ice-adhesion coating of claim 1 , wherein said average length scale of phase inhomogeneity is from about 1 micron to about 50 microns.

3. The low-ice-adhesion coating of claim 1 , wherein said coating is characterized by an AMIL Centrifuge Ice Adhesion Reduction Factor of about 25 or more.

4. The low-ice-adhesion coating of claim 3 , wherein said coating is characterized by an AMIL Centrifuge Ice Adhesion Reduction Factor of about 100 or more.

5. The low-ice-adhesion coating of claim 1 , wherein one of said first-material phase and said second-material phase is hydrophobic, and the other is hydrophilic.

6. The low-ice-adhesion coating of claim 1 , wherein one of said first-material phase and said second-material phase is omniphobic, and the other is hydrophilic.

7. The low-ice-adhesion coating of claim 1 , wherein one of said first-material phase and said second-material phase is hydrophobic, and the other is hygroscopic.

8. The low-ice-adhesion coating of claim 7 , wherein said hygroscopic phase includes polyethylene glycol.

9. The low-ice-adhesion coating of claim 1 , wherein one of said first-material phase and said second-material phase is hygroscopic, and the other comprises a low-surface-energy polymer having a surface energy between about 5 mJ/m 2 to about 50 mJ/m 2 .

10. The low-ice-adhesion coating of claim 9 , wherein said low-surface-energy polymer consists of said fluoropolymers.

11. The low-ice-adhesion coating of claim 10 , wherein said fluoropolymers are is selected from the group consisting of polyfluoroethers, perfluoropolyethers, polyfluoroacrylates, polyfluorosiloxanes, polytetrafluoroethylene, polyvinylidene difluoride, polyvinylfluoride, polychlorotrifluoroethylene, copolymers of ethylene and trifluoroethylene, copolymers of ethylene and chlorotrifluoroethylene, and combinations thereof.

12. The low-ice-adhesion coating of claim 11 , wherein said fluoropolymers consist of perfluoropolyether.

13. The low-ice-adhesion coating of claim 1 , wherein said first-material phase and said second-material phase are connected by polymer chain extension.

14. The low-ice-adhesion coating of claim 1 , wherein said first-material phase and said second-material phase are connected by polymer crosslinking.

15. The low-ice-adhesion coating of claim 1 , wherein said block copolymer is a segmented urethane/urea block copolymer.

16. The low-ice-adhesion coating of claim 1 , wherein said fluoropolymers include a fluoropolymer having the structure:

wherein:
X, Y=CH 2 —(O—CH 2 —CH 2 ) p —OH wherein p=0 to 50 and wherein X and Y are independently selected;
m=1 to 100; and
n=1 to 100.

Assignees

• Hrl Lab Llc

Inventors

• Nowak Andrew P
• Rodriguez April R
• Sherman Elena
• Gross Adam F

Classifications

• C08G18/12

  using two or more compounds having active hydrogen in the first polymerisation step · CPC title

• C09D175/08

  from polyethers · CPC title

• B05D5/083

  involving the use of fluoropolymers · CPC title

• B05D3/007

  After-treatment · CPC title

• B05D1/02

  performed by spraying · CPC title