Single-component coating having alkoxysilane-terminated N-substituted urea resins
View Patent ↗The coating described herein attempts to provide this solution by synthesizing alkoxysilane-terminated N-substituted urea resins, then formulating them into moisture-curable single-component (1K) topside coatings. These coatings will provide greater external stability (to UV and visible radiation), cleanability, flexibility, cure times and lower VOC content than the currently qualified silicone alkyd topside coatings that are found on Navy ships. The single-component coating can include at least an alkoxysilane-terminated N-substituted urea resin, a reactive diluent, a pigment, a filler, and a catalyst. The resin can include an amino-functional silane substituted at the N-position and a non-aromatic isocyanate.
1. A single-component coating comprising:
an alkoxysilane-terminated N-substituted urea resin, formed by reacting (i) an aliphatic polyisocyanate and a mixture of (ii) an amino-functional siloxane which is substituted at the N-position with a group selected from C3-C6 alkyl, cyclohexyl, and phenyl and (iii) a disubstituted amine NR 1 R 2 , where each of R 1 and R 2 is independently an aliphatic, cycloaliphatic, or aromatic group;
such that said resin has no free isocyanate groups;
and further comprising a reactive diluent; a pigment; a filler; and a catalyst.
2. The single-component coating according to claim 1 , wherein the alkoxysilane-terminated N-substituted urea resin is formed from said mixture of amino-functional siloxane (ii) and disubstituted amine (iii), in a 1:2 ratio, and said aliphatic polyisocyanate.
3. The single-component coating according to claim 1 , wherein the alkoxysilane-teiminated N-substituted urea resin is formed from said mixture of amino-functional siloxane (ii) and disubstituted amine (iii), in a 2:1 ratio, and said aliphatic polyisocyanate.
4. The single-component coating according to claim 1 , wherein the amino-functional siloxane is selected from the group consisting of:
N-butyl-3-aminopropyltrimethoxysilane,
N-butyl-3-aminopropylmethyldimethoxysilane,
N-butyl-3-aminopropyltriethoxysilane,
N-ethyl-3-aminopropyltriethoxysilane,
N-cyclohexyl-3-aminopropyltrimethoxysilane,
N-phenyl-3-aminopropyltrimethoxysilane,
N-hexyl-3-aminopropyltrimethoxysilane,
N-pentyl-3-aminopropyltrimethoxysilane,
N-isopropyl-3-aminopropyltrimethoxysilane, and
N-isobutyl-3-aminopropyltrimethoxysilane.
5. The single-component coating according to claim 1 , wherein the aliphatic polyisocyanate is selected from the group consisting of:
aliphatic polyisocyanate based on HDI trimer,
aliphatic polyisocyanate based on HDI uretdione,
aliphatic polyisocyanate based on HDI biuret,
aliphatic polyisocyanate based on HDI allophanate trimer, and
aliphatic polyisocyanate based on asymmetric HDI trimer.
6. The single-component coating according to claim 1 , wherein the reactive diluent is a silicone-based diluent.
7. The single-component coating according to claim 6 , wherein the reactive diluent is selected from the group consisting of:
oligomeric methyl silicates,
hexyltrimethoxysilane,
octylmethyldiethoxysilane,
n-octyltrimethoxysilane, and
methoxy functional silicone.
8. The single-component coating according to claim 1 , wherein the alkoxysilane-terminated N-substituted urea resin comprises about 61 to 71 percent of the coating by weight.
9. A resin formed by reacting
(i) an aliphatic polyisocyanate and a mixture of (ii) an amino-functional siloxane which is substituted at the N-position with a group selected from C3-C6 alkyl, cyclohexyl, and phenyl and (iii) a disubstituted amine NR 1 R 2 , where each of R 1 and R 2 is independently an aliphatic, cycloaliphatic, or aromatic group; such that said resin has no free isocyanate groups.
10. The resin according to claim 9 , wherein the amino-functional siloxane is selected from the group consisting of:
N-butyl-3-aminopropyltrimethoxysilane,
N-butyl-3-aminopropylmethyldimethoxysilane,
N-butyl-3-aminopropyltriethoxysilane,
N-ethyl-3-aminopropyltriethoxysilane,
N-cyclohexyl-3-aminopropyltrimethoxysilane,
N-phenyl-3-aminopropyltrimethoxysilane,
N-hexyl-3-aminopropyltrimethoxysilane,
N-pentyl-3-aminopropyltrimethoxysilane,
N-isopropyl-3-aminopropyltrimethoxysilane, and
N-isobutyl-3-aminopropyltrimethoxysilane.
11. The resin according to claim 9 , wherein the aliphatic polyisocyanate is selected from the group consisting of:
aliphatic polyisocyanate based on HDI trimer,
aliphatic polyisocyanate based on HDI uretdione,
aliphatic polyisocyanate based on HDI biuret,
aliphatic polyisocyanate based on HDI allophanate trimer,
aliphatic polyisocyanate based on asymmetric HDI trimer.
12. A method for producing a single-component coating, the method comprising:
synthesizing a resin from
an aliphatic polyisocyanate and a mixture of (ii) an amino-functional siloxane which is substituted at the N-position with a group selected from C3-C6 alkyl, cyclohexyl, and phenyl and (iii) a disubstituted amine NR 1 R 2 , where each of R 1 and R 2 is independently an aliphatic, cycloaliphatic, or aromatic group; such that said resin has no free isocyanate groups; and
mixing the synthesized resin with a reactive diluent, a pigment, a filler, and a catalyst.
13. The method according to claim 12 , wherein the amino-functional siloxane is selected from the group consisting of:
N-butyl-3-aminopropyltrimethoxysilane,
N-butyl-3-aminopropylmethyldimethoxysilane,
N-butyl-3-aminopropyltriethoxysilane,
N-ethyl-3-aminopropyltriethoxysilane,
N-cyclohexyl-3-aminopropyltrimethoxysilane,
N-phenyl-3-aminopropyltrimethoxysilane,
N-hexyl-3-aminopropyltrimethoxysilane,
N-pentyl-3-aminopropyltrimethoxysilane,
N-isopropyl-3-aminopropyltrimethoxysilane, and
N-isobutyl-3-aminopropyltrimethoxysilane.
14. The method according to claim 12 , wherein the aliphatic polyisocyanate is selected from the group consisting of:
aliphatic polyisocyanate based on HDI trimer,
aliphatic polyisocyanate based on HDI uretdione,
aliphatic polyisocyanate based on HDI biuret,
aliphatic polyisocyanate based on HDI allophanate trimer,
aliphatic polyisocyanate based on asymmetric HDI trimer.
15. The method according to claim 12 , wherein the reactive diluent is a silicone-based reactive diluent.
16. The method according to claim 12 , wherein the reactive diluent is selected from the group consisting of:
oligomeric methyl silicates,
hexyltrimethoxysilane,
octylmethyldiethoxysilane,
n-octyltrimethoxysilane, and
methoxy functional silicone.