Marine anti-fouling coating composition

A non-leaching coating composition useful in preventing fouling of marine structures submerged in water which composition is prepared as a single component composition by comingling a polyol reactive organic polyisocyanate, a hydroxy functional acylic polymer, and an organotin polymer in the presence of a reactivity suppressant solvent medium comprising a mixture of low molecular weight ketones and hydroxy-functional ether or low molecular weight aliphatic alcohol compounds.

We claim:

1. A single component coating composition having optically clear film characteristics particularly suitable for preventing growth of fouling organisms on marine structures, said composition comprising:

a hydroxy functional acrylic polymer;

a biologically active organotin polymer of the formula

R.sub.3 Sn--OOCR'

wherein R is selected from the group consisting of lower alkyl, phenyl and benzyl and R' is a polymerizable radical selected from the group consisting of vinyl, methyl vinyl and vinylphenyl;

a polyol reactive polyisocyanate; and

a reaction inhibiting solvent medium comprising a mixture of at least one low molecular weight ketone and a co-solvent selected from the group consisting of hydroxyethers, linear alcohols and isopropyl alcohol.

2. A single component coating composition according to claim 1 wherein said polyol reactive polyisocyanate is the reaction product of hexamethylene diisocyanate and water.

3. A single component coating composition according to claim 1 wherein said acrylic polymer is selected from the group consisting of hydroxy ethyl methacrylate and hydroxy propyl methacrylate.

4. A single component coating composition for preventing growth of fouling organisms on marine structures, said composition prepared by the method which comprises:

(a) obtaining a first solution comprising a mixture of low molecular weight ketones and hydroxy functional organic compounds selected from hydroxy ethers, linear alcohols and isopropyl alcohol;

(b) admixing said first solution with a hydroxy functional acrylic polymer selected from the group consisting of polyacrylates, polymethacrylates and copolymers thereof with at least one additional copolymerizable monomer, to form a second solution;

(c) adding to said second solution an organotin polymer being a biologically active compound of the formula

R.sub.3 Sn--OOCR'

wherein R is selected from the group consisting of lower alkyl, phenyl and benzyl and R' is a polymerizable radical selected from the group consisting of vinyl, methyl vinyl and vinylphenyl to form a third solution; and

(d) adding to said third solution a polyol reactive polyisocyanate to form a fourth solution as said single component coating composition.

5. A single component coating composition according to claim 4 wherein said polyol reactive polyisocyanate is the reaction product of hexamethylene diisocyanate and water.

6. A single component coating composition according to claim 4 wherein said medium comprises a mixture of low molecular weight ketones, an hydroxy ether and a linear alcohol.

7. A single component coating composition according to claim 5 wherein said acrylic polymer is selected from the group consisting of hydroxy ethyl methacrylate and hydroxy propyl methacrylate.

8. A single component coating composition having optically clear film characteristics for preventing growth of fouling organisms on marine structures prepared by the method which comprises:

(a) comingling

(i) poly(2-hydroxy ethyl methacrylate),

(ii) poly(tri-n-buyltin methacrylate), and

(iii) poly(hexamethylene diisocyanate),

(b) in the presence of a medium comprising methyl ethyl ketone, cyclohexanone, ethylene glycol ethyl ether acetate, isopropyl alcohol, and ethylene glycol mono ethyl ether.

9. A single component coating composition according to claim 8 wherein said medium additionally contains cellulose acetate butyrate.

10. A single component coating composition according to claim 8 wherein said poly(2-hydroxy ethyl methacrylate) comprises from 5% to 15% by weight, said poly(tri-n-butyltin methacrylate) comprises from 40% to 60% by weight, said poly(hexamethylene diisocyanate) comprises 2% to 5% by weight, and said medium comprises 25% to 45% by weight.

11. A single component coating composition according to claim 10 wherein said medium additionally contains from 0.5% to 3% by weight cellulose acetate butyrate.

12. The process of protecting marine structures against the growth of fouling organisms which comprises treating said structures with a hydrophobic polymeric film, said film produced by removal of solvent from a single component composition produced by comingling

a hydroxy functional acrylic polymer;

a biologically active organotin polymer of the formula

R.sub.3 Sn--OOCR'

wherein R is selected from the group consisting of lower alkyl, phenyl and benzyl and R' is a polymerizable radical selected from the group consisting of vinyl, methylvinyl and vinylphenyl;

a polyol reactive polyisocyanate; and

a reaction inhibiting solvent medium comprising a mixture of at least one low molecular weight ketone and a co-solvent selected from the group consisting of hydroxyethers, linear alcohols and isopropyl alcohol.

13. The process of protecting marine structures against the growth of fouling organisms which comprises treating said structures with a hydrophobic polymeric film, said film produced by the removal of solvent from a single component composition produced by comingling

poly(2-hydroxyethyl methacrylate);

poly(tri-n-butyltin methacrylate); and

poly(hexamethylene diisocyanate)

in the presence of a reaction inhibiting solvent medium comprising methyl ethyl ketone, cyclohexanone, ethylene glycol ethyl ether acetate, isopropyl alcohol and ethylene glycol monoethyl ether.

14. The process according to claim 13 wherein said poly(2-hydroxy ethyl methacrylate) comprises from 5% to 15% by weight, said poly(tri-n-butyltin methacrylate) comprises from 40% to 60% by weight, said poly(hexamethylene diisocyanate) comprises to 2% to 5% by weight, and said medium comprises 25% to 45% by weight.

15. The method of protecting a boat hull against fouling by organisms present in the surrounding water which comprises painting at that portion of the boat hull below the water line with a paint which is prepared as a single component composition by:

(a) comingling

(i) poly(2-hydroxy ethyl methacrylate),

(ii) poly(tri-n-butyltin methacrylate), and

(iii) poly(hexamethylene diisocyanate),

(b) in the presence of a medium comprising methyl ethyl ketone, cyclohexanone, ethylene glycol ethyl ether acetate, isopropyl alcohol, and ethylene glycol mono ethyl ether.

16. Method according to claim 15 wherein said poly(2-hydroxy ethyl methacrylate) comprises from 5% to 15% by weight, said poly(tri-n-butyltin methacrylate) comprises from 40% to 60% by weight, said poly(hexamethylene diisocyanate) comprises 2% to 5% by weight, and said medium comprises 25% to 45% by weight.

17. A single component coating composition having optically clear film characteristics for preventing growth of fouling organisms on marine structure prepared by the method which comprises:

(a) comingling

(i) 5% to 15% by weight poly(2-hydroxy ethyl methacrylate),

(ii) 40% to 60% by weight poly(tri-n-butyltin methacrylate), and

(iii) 2% to B 5% by weight poly(hexamethylene diisocyanate),

(b) in the presence of a medium comprising methyl ethyl ketone, cyclohexanone, ethylene glycol ethyl ether acetate, isopropyl alcohol, and ethylene glycol mono ethyl ether, said medium comprising 25% to 45% by weight of said composition, said medium comprising, by weight of total medium, 30% to 50% methyl ethyl ketone, 15% to 30% cyclohexanone, 15% to 30% ethylene glycol ether acetate, 5% to 15% isopropyl alcohol, and 5% to 15% ethylene glycol monoethyl ether.

18. The process of protecting marine structures against the growth of fouling organisms which comprises treating said structures with a hydrophobic polymeric film which is prepared as a single component composition by:

(a) comingling

(i) 5% to 15% by weight poly(2-hydroxy ethyl methacrylate),

(ii) 40% to 60% by weight poly(tri-n-buyltin methacrylate), and

(iii) 2% to 5% by weight poly(hexamethylene diisocyanate),

(b) in the presence of a medium comprising methyl ethyl ketone, cyclohexanaone, ethylene glycol ethyl ether acetate, isopropyl alcohol, and ethylene glycol mono ethyl ether, said medium comprising 25% to 45% by weight of said composition, said medium comprising, by weight of total medium, 30% to 50% methyl ethyl ketone, 15% to 30% cyclohexanone, 15% to 30% ethylene glycol ether acetate, 5% to 15% isopropyl alcohol, and 5% to 15% ethylene glycol monoethyl ether.

19. The method of protecting a boat hull against fouling by organisms present in surrounding water which comprises painting that portion of said boat hull below the waterline with a paint prepared as a single component system by comingling

a hydroxy-functional acrylic polymer;

a biologically active organotin polymer of the formula

R.sub.3 Sn--OOCR'

wherein R is selected from the group consisting of lower alkyl, phenyl and benzyl and R' is a polymerizable radical selected from the group consisting of vinyl, methylvinyl and vinylphenyl;

a polyol reactive polyisocyanate; and

a reaction inhibiting solvent medium comprising a mixture of at least one low molecular weight ketone and a co-solvent selected from the group consisting of hydroxyethers, linear alcohols and isopropyl alcohol.

20. The method of protecting a boat hull against fouling by organisms present in the surrounding water which comprises painting at that portion of the boat hull below the water line with a paint which is prepared as a single component composition by:

(a) comingling

(i) 5% to 15% by weight poly(2-hydroxy ethyl methacrylate),

(ii) 40% to 60% by weight poly(tri-n-buyltin methacrylate), and

(iii) 2% to 5% by weight poly(hexamethylene diisocyanate),

(b) in the presence of a medium comprising methyl ethyl ketone, cyclohexanone, ethylene glycol ethyl ether acetate, isopropyl alcohol, and ethylene glycol mono ethyl ether, said medium comprising 25% to 45% by weight of said composition, said medium comprising, by weight of total medium, 30% to 50% methyl ethyl ketone, 15% to 30% cyclohexanone, 15% to 30% ethylene glycol ether acetate, 5% to 15% isopropyl alcohol, and 5% to 15% ethylene glycol monoethyl ether.