Amphiphilic siloxane-polyurethane fouling-release coatings

1 . A curable coating composition comprising:

a) at least one surface modifying amphiphilic additive (SMAA), comprising the reaction product of:

a1) at least one Si-H functional siloxane; and

a2) at least one allyl-functional poly (ethylene glycol) methyl ether (allyl-functional mPEG);

b) at least one polyisocyanate;

c) at least one polyol; and

d) at least one amphiphilic mPEG-polydimethylsiloxane (PDMS) isocyanate pre-polymer, comprising the reaction product of:

d1 at least one polyisocyanate;

d2) at least one monocarbinol-terminated PDMS; and

d3) at least one poly (ethylene glycol) methyl ether (mPEG),

wherein the at least one amphiphilic mPEG-PDMS isocyanate prepolymer, d), has an overall isocyanate to total hydroxyl equivalent ratio such that isocyanate is in excess, and wherein the SMAA, a), has the following structure:

wherein:

X is

l ranges from 5 to 6;

m ranges from 0 to 13; and

n ranges from 2 to 18.

2 . The curable coating composition of claim 1 , wherein the SMAA, a), is present in an amount ranging from about 0.1-40 wt. %, based on the solid content of the curable coating composition.

3 . The curable coating composition of claim 1 , wherein the Si—H functional siloxane, a1), and the allyl-functional mPEG, a2), are reacted in a 1.0:1.0 molar equivalent ratio.

4 . The curable coating composition of claim 1 , wherein the Si—H functional siloxane, a1), has the following structure:

wherein:

m ranges from 0 to 13; and

n ranges from 2 to 18.

5 . The curable coating composition of claim 1 , wherein the Si—H functional siloxane, a1), is selected from the group consisting of a 100 mol % Si—H polymethylhydrosiloxane, a copolymer of methylhydrosiloxane-dimethylsiloxane of varying mol % Si—H, a tetra functional Si—H cyclosiloxane, and mixtures thereof.

6 . The curable coating composition of claim 1 , wherein the polyisocyanate, b) and d1), are, independent of one another, selected from the group consisting of an aliphatic polyisocyanate, a cycloaliphatic polyisocyanate, an araliphatic polyisocyanate, an aromatic polyisocyanate, and mixtures thereof.

7 . The curable coating composition of claim 6 , wherein the polyisocyanate, b) and d1), are, independent of one another, selected from the group consisting of:

wherein R is independently divalent C 1 -C 15 alkyl, C 3 -C 15 cycloalkyl, or a group selected from:

8 . The curable coating composition of claim 6 , wherein the polyisocyanate, b) and d1), are isophorone diisocyanate and trimers thereof.

9 . The curable coating composition of claim 1 , wherein the polyol, c), is selected from the group consisting of a polyester polyol, a polyether polyol, a polycarbonate polyol, an acrylic polyol, and mixtures thereof.

10 . The curable coating composition of claim 9 , wherein the polyol, c), is selected from an acrylic polyol.

11 . The curable coating composition of claim 1 , wherein the isocyanate to total hydroxyl equivalent ratio in the amphiphilic mPEG-PDMS isocyanate prepolymer, d), ranges from 1.5:1 to 1.1:1.

12 . The curable coating composition of claim 1 , wherein the at least one amphiphilic mPEG-PDMS isocyanate prepolymer, d), contains monocarbinol-terminated PDMS, d2): mPEG, d3) in a ratio ranging from 0.1:20 wt. % to 20:0.1 wt. %, based on the solid content of the amphiphilic mPEG-PDMS isocyanate prepolymer, d).

13 . The curable coating composition of claim 1 , wherein the monocarbinol-terminated PDMS, d2), has the following structure:

wherein R, independent of one another, is a C 3 -C 12 straight chain alkyl or an alkylene ether;

wherein n ranges from 0 to about 270.

14 . A cured coating composition comprising the curable coating composition of claim 1 .

15 . An object coated with the curable coating composition of claim 1 .

16 . A method for reducing or preventing biofouling of a surface exposed to an aqueous environment comprising the steps of:

coating at least a portion of the surface with a curable coating composition of claim 1 to form a coated surface, and

curing the coating composition on the coated surface.

17 . A marine fouling-release coating comprising the curable coating composition of claim 1 .