Low-adhesion coatings with solid-state lubricants

Patent metadata

Field	Value
Publication number	US-2017298286-A1
Application number	US-201715638340-A
Country	US
Kind code	A1
Filing date	Jun 29, 2017
Priority date	Mar 14, 2014
Publication date	Oct 19, 2017
Grant date	—

Abstract

Some variations provide a low-adhesion coating comprising a continuous matrix containing a first component, a plurality of inclusions containing a second component, and a solid-state lubricant distributed within the coating, wherein one of the first component or the second component is a low-surface-energy polymer, and the other of the first component or the second component is a hygroscopic material. The solid-state lubricant may be selected from graphite, graphene, molybdenum disulfide, tungsten disulfide, hexagonal boron nitride, or poly(tetrafluoroethylene) or other fluoropolymers. The solid-state lubricant particles may be coated with a metal selected from cadmium, lead, tin, zinc, copper, nickel, or alloys containing one or more of these metals. The solid-state lubricant is typically characterized by an average particle size from about 0.1 μm to about 500 μm. The solid-state lubricant is preferably distributed throughout the coating.

First claim

What is claimed is:

1 . A low-adhesion composition comprising:
(a) fluoropolymers that are present in the triblock structure:

wherein:
X, Y═CH 2 —(O—CH 2 —CH 2 ) p -T, and X and Y are independently selected;
p=1 to 50;
T is a hydroxyl or amine terminal group;
m=1 to 100; and
n=1 to 100;
(b) one or more isocyanate species possessing an average isocyanate functionality of about 2 or greater, or a reacted form thereof;
(c) one or more polyol or polyamine chain extenders or crosslinkers possessing an average functionality of about 2 or greater, or a reacted form thereof; and
(d) one or more solid-state lubricants distributed throughout said composition.

2 . The low-adhesion composition of claim 1 , wherein said solid-state lubricants are selected from the group consisting of graphite, graphene, molybdenum disulfide, tungsten disulfide, hexagonal boron nitride, poly(tetrafluoroethylene), fluoropolymers, and combinations thereof.

3 . The low-adhesion composition of claim 1 , wherein said solid-state lubricants are particles having outer surfaces containing a metal selected from the group consisting of cadmium, lead, tin, zinc, copper, nickel, and combinations or alloys thereof.

4 . The low-adhesion composition of claim 1 , wherein said solid-state lubricants have an average particle size from about 0.1 μm to about 500 μm.

5 . The low-adhesion composition of claim 1 , wherein said solid-state lubricants are distributed uniformly throughout said composition.

6 . The low-adhesion composition of claim 1 , wherein said fluoropolymers have an average molecular weight from about 1,000 g/mol to about 10,000 g/mol.

7 . The low-adhesion composition of claim 1 , wherein p is selected from 6 to 50 for each of X and Y.

8 . The low-adhesion composition of claim 1 , wherein said isocyanate species are selected from the group consisting of 4,4′-methylenebis(cyclohexyl isocyanate), hexamethylene diisocyanate, cycloalkyl-based diisocyanates, tolylene-2,4-diisocyanate, 4,4′-methylenebis(phenyl isocyanate), isophorone diisocyanate, and combinations or derivatives thereof.

9 . The low-adhesion composition of claim 1 , wherein said polyol or polyamine chain extenders or crosslinkers are selected from the group consisting of 1,3-butanediol, 1,4-butanediol, 1,3-propanediol, 1,2-ethanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, ethanol amine, diethanol amine, methyldiethanolamine, phenyldiethanolamine, glycerol, trimethylolpropane, 1,2,6-hexanetriol, triethanolamine, pentaerythritol, ethylenediamine, 1,3-propanediamine, 1,4-butanediamine, diethyltoluenediamine, dimethylthiotoluenediamine, isophoronediamine, diaminocyclohexane, N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine, and homologues, derivatives, or combinations thereof.

10 . The low-adhesion composition of claim 1 , wherein said composition contains, in a hard segment, said reacted form of said one or more isocyanate species, combined with said reacted form of said one or more polyol or polyamine chain extenders or crosslinkers.

11 . A low-adhesion coating comprising:
(a) a substantially continuous matrix containing a first component; (b) a plurality of inclusions containing a second component, wherein said inclusions are dispersed within said matrix; and (c) a solid-state lubricant distributed within said matrix and/or within said inclusions, wherein one of said first component or said second component is a low-surface-energy polymer having a surface energy between about 5 mJ/m 2 to about 50 mJ/m 2 , and the other of said first component or said second component is a hygroscopic material.

12 . The low-adhesion coating of claim 11 , wherein said solid-state lubricant is distributed throughout said coating.

13 . The low-adhesion coating of claim 11 , wherein said solid-state lubricant is selected from the group consisting of graphite, graphene, molybdenum disulfide, tungsten disulfide, hexagonal boron nitride, poly(tetrafluoroethylene), fluoropolymers, and combinations thereof.

14 . The low-adhesion coating of claim 11 , wherein said solid-state lubricant is a plurality of particles having outer surfaces containing a metal selected from the group consisting of cadmium, lead, tin, zinc, copper, nickel, and combinations or alloys thereof.

15 . The low-adhesion coating of claim 11 , wherein said solid-state lubricant is characterized by an average particle size from about 0.1 μm to about 500 μm.

16 . The low-adhesion coating of claim 11 , wherein said polymer is a fluoropolymer selected from the group consisting of polyfluoroethers, perfluoropolyethers, polyfluoroacrylates, polyfluorosiloxanes, and combinations thereof.

17 . The low-adhesion coating of claim 16 , wherein said fluoropolymer is perfluoropolyether and wherein said hygroscopic material is poly(ethylene glycol).

18 . The low-adhesion coating of claim 16 , wherein said hygroscopic material is covalently connected to said fluoropolymer in a triblock copolymer.

19 . The low-adhesion coating of claim 18 , wherein said triblock copolymer has the structure:

wherein:
X, Y═CH 2 —(O—CH 2 —CH 2 ) p -T, and X and Y are independently selected;
p=1 to 50;
T is a hydroxyl or amine terminal group;
m=1 to 100; and
n=1 to 100.

20 . The low-adhesion coating of claim 11 , wherein said hygroscopic material is selected from the group consisting of poly(acrylic acid), poly(ethylene glycol), poly(2-hydroxyethyl methacrylate), poly(vinyl imidazole), poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), poly(vinylpyrolidone), cellulose, modified cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydrogels, PEG diacryalate, monoacrylate, and combinations thereof.

21 . The low-adhesion coating of claim 11 , wherein said continuous matrix further contains (i) one or more isocyanate species possessing an average isocyanate functionality of about 2 or greater, or a reacted form thereof and (ii) one or more polyol or polyamine chain extenders or crosslinkers possessing an average functionality of about 2 or greater, or a reacted form thereof.

22 . The low-adhesion material of claim 21 , wherein said isocyanate species are selected from the group consisting of 4,4′-methylenebis(cyclohexyl isocyanate), hexamethylene diisocyanate, cycloalkyl-based diisocyanates, tolylene-2,4-diisocyanate, 4,4′-methylenebis(phenyl isocyanate), isophorone diisocyanate, and combinations or derivatives thereof.

23 . The low-adhesion coating of claim 21 , wherein said polyol or polyamine chain extenders or crosslinkers are selected from the group consisting of 1,3-butanediol, 1,4-butanediol, 1,3-propanediol, 1,2-ethanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, ethanol amine, diethanol amine, methyldiethanolamine, phenyldiethanolamine, glycerol, trimethylolpropane, 1,2,6-hexanetriol, triethanolamine, pentae

Assignees

• Hrl Lab Llc

Inventors

• Nowak Andrew P
• Sherman Elena
• Gross Adam F

Classifications

• C10N2050/08

  Solids · CPC title

• C10M2213/0606

  used as base material · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C09D175/08

  from polyethers · CPC title

• C10M2217/0453

  used as base material · CPC title