Amphiphilic siloxane-polyurethane fouling-release coatings and uses thereof

Patent metadata

Field	Value
Publication number	US-10647878-B2
Application number	US-201615576399-A
Country	US
Kind code	B2
Filing date	Jun 1, 2016
Priority date	Jun 1, 2015
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

The invention is directed to curable polyurethane coating compositions which may be used to form fouling release coatings, e.g., for use in protecting boat hulls. The curable polyurethane coating compositions of the invention comprise (a) a prepolymer made by reacting at least one polyisocyanate with (i) at least one monocarbinol-terminated poly(dimethylsiloxane), (ii) at least one methoxy-terminated poly(ethylene glycol), or (iii) mixtures thereof, (b) at least one polyol, and (c) at least one polyisocyanate crosslinker. The invention also relates to the prepolymer used in the curable coating compositions. The invention further relates to methods for reducing or preventing biofouling of a surface exposed to an aqueous environment comprising the steps of coating the surface with a curable coating composition of the invention to form a coated surface, and curing the coating coating composition on the coated surface.

First claim

The claimed invention is:

1. A curable polyurethane coating composition comprising:
a) a prepolymer made by reacting at least one polyisocyanate with
i) at least one monocarbinol-terminated poly(dimethylsiloxane); and
ii) at least one methoxy-terminated poly(ethylene glycol);

b) at least one polyol; and
c) at least one polyisocyanate crosslinker,

wherein the polyisocyanate in a) may be the same or different as the polyisocyanate crosslinker c).

2. A curable coating composition of claim 1 , wherein the prepolymer has a 3:2 isocyanate to hydroxyl ratio and having 5-10 weight % of polyl(dimethylsiloxane) and poly(ethylene glycol) content based on the overall coating formulation.

3. A curable coating composition of claim 2 , wherein
the polyisocyanate is a trimer of methylene diphenyl diisocyanate, hexamethylene diisocyanate, or isophorone diisocyanate; and
the polyol is an acrylic polyol or a polyether polyol.

4. A prepolymer of claim 2 , wherein:
the monocarbinol-terminated poly(dimethylsiloxane) has a molecular weight from 500 to 15,000 g/mole, and
the methoxy-terminated poly(ethylene glycol) has a molecular weight ranging from 400 to 1,000 g/mole.

5. A curable coating composition of claim 2 , wherein:
the prepolymer (a) is present in an amount ranging from 20 wt. % to 60 wt. %,
the polyol (b) is present in an amount ranging from 20 wt. % to 60 wt. %, and
the polyisocyanate crosslinker is present in an amount ranging from 10 wt. % to 40 wt. %;
further comprising a solvent in an amount from 0.5 wt. % to 50 wt. %, and
having an overall isocyanate to total hydroxyl ratio of 1.2:1 or 1.1:1.

6. The curable coating composition of claim 5 , wherein the polyisocyanate is a polyisocyanate derived from isophorone diisocyanate and the polyol is an acrylic polyol.

7. A curable coating composition of claim 1 , having an overall isocyanate to total hydroxyl equivalence where the isocyanate is in a slight molar excess.

8. A curable coating composition of claim 1 , wherein:
the prepolymer (a) is present in an amount ranging from 20 wt. % to 60 wt. %,
the polyol (b) is present in an amount ranging from 20 wt. % to 60 wt. %, and
the polyisocyanate crosslinker is present in an amount ranging from 10 wt. % to 40 wt. %;
further comprising a solvent in an amount from 0.5 wt. % to 50 wt. %, and
having an overall isocyanate to total hydroxyl ratio of 1.2:1 or 1.1:1.

9. The curable coating composition of claim 8 , wherein the polyisocyanate is a polyisocyanate derived from isophorone diisocyanate and the polyol is an acrylic polyol.

10. A cured coating composition of claim 1 .

11. An object coated with the coating composition of claim 1 .

12. An object of claim 11 , wherein the object is a boat hull.

13. A method for reducing or preventing biofouling of a surface exposed to an aqueous environment comprising the steps of:
coating the surface with a curable coating composition of claim 1 to form a coated surface, and
curing the coating composition on the coated surface.

14. A marine fouling-release coating having the composition of claim 1 .

15. A prepolymer made by reacting at least one polyisocyanate with
i) at least one monocarbinol-terminated poly(dimethylsiloxane); and
ii) at least one methoxy-terminated poly(ethylene glycol).

16. A prepolymer of claim 15 , wherein the prepolymer has a 3:2 isocyanate to hydroxyl ratio.

17. A prepolymer of claim 15 , wherein the polyisocyanate is a trimer of methylene diphenyl diisocyanate, hexamethylene diisocyanate, or isophorone diisocyanate.

18. A prepolymer of claim 15 , wherein:
the monocarbinol-terminated poly(dimethylsiloxane) has a molecular weight from 500 to 15,000 g/mole, and
the methoxy-terminated poly(ethylene glycol) has a molecular weight ranging from 400 to 1,000 g/mole.

Assignees

• Ndsu Res Foundation

Inventors

• Webster Dean C
• Galhenage Teluka

Classifications

• C09D175/08 Primary

  from polyethers · CPC title

• C08G18/792

  formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates · CPC title

• C08G18/289

  containing silicon · CPC title

• C08G18/725

  Combination of polyisocyanates of C08G18/78 with other polyisocyanates · CPC title

• C08G18/8064

  with monohydroxy compounds · CPC title