Microencapsulated nitrification inhibitor compositions
The present disclosure relates to an improved nitrification inhibitor composition and its use in agricultural applications.
1. A microcapsule suspension formulation comprising:
(a) a suspended phase of a plurality of microcapsules having a volume median particle size of from about 1 to about 10 microns, wherein the microcapsules comprise:
(1) a microcapsule wall produced by an interfacial polycondensation reaction between a polymeric isocyanate and a polyamine to form a polyurea shell;
(2) at least one organic nitrification inhibiting compound encapsulated within the polyurea shell;
(3) at least one polymeric ultra-hydrophobe compound encapsulated within the polyurea shell; and
(b) an aqueous phase including a hydrophobic crystal inhibitor additive.
2. The microcapsule suspension formulation according to claim 1 , wherein the aqueous phase further includes at least one additional ingredient selected from the group consisting of: a dispersant, a nonionic polymer, an antifoam, and a biocide.
3. The microcapsule suspension formulation according to claim 1 , wherein the microcapsules comprise 2-chloro-6-(trichloromethyl)pyridine.
4. The microcapsule suspension formulation according to claim 1 , wherein the formulation further comprises an agricultural active ingredient selected from the group consisting of: arthropodicides, bactericides, fungicides, herbicides, insecticides, miticides, nematicides, fertilizers, dicyandiamide, urease inhibitors, and pesticidal mixtures thereof.
5. The microcapsule suspension formulation according to claim 3 , wherein the formulation comprises between about 25 weight percent and about 35 weight percent 2-chloro-6-(trichloromethyl)pyridine.
6. The microcapsule suspension formulation according to claim 1 , wherein the formulation comprises between about 0.1 weight percent and about 2.00 weight percent of the at least one polymeric ultra-hydrophobe compound.
7. The microcapsule suspension formulation according to claim 6 , wherein the microcapsules comprise a polybutene.
8. The microcapsule suspension formulation according to claim 1 , wherein the aqueous phase comprises between about 1.0 weight percent and about 4.0 weight percent of the hydrophobic crystal inhibitor additive.
9. The microcapsule suspension formulation according to claim 1 , wherein the hydrophobic crystal inhibitor additive includes at least one compound selected from the group consisting of: aromatic solvents and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.
10. The microcapsule suspension formulation according to claim 2 , wherein the aqueous phase comprises between about 1.0 weight percent and about 10 weight percent nonionic polymer.
11. The microcapsule suspension formulation according to claim 10 , wherein the nonionic polymer is a polyvinyl alcohol.
12. The microcapsule suspension formulation according to claim 1 , wherein the aqueous phase includes at least one additive selected from the group consisting of: modified styrene acrylic polymeric surfactant, nonionic polymer, aqueous emulsion of polydimethylsiloxane concentrate, xanthan gum, microcrystalline cellulose, carboxymethyl-cellulose sodium, and propylene glycol.
13. The microcapsule suspension formulation according to claim 1 , wherein the formulation comprises between about 40 weight percent and about 70 weight percent of the aqueous phase.
14. A method for making a microcapsule suspension formulation comprising the steps of:
(a) preparing a lipophilic phase comprising at least one lipophilic isocyanate and at least one polymeric ultra-hydrophobe by mixing said at least one lipophilic isocyanate and said at least one polymeric ultra-hydrophobe in at least one molten organic nitrification inhibiting compound;
(b) preparing an aqueous phase by dissolving and mixing in water at least one first additive selected from the group consisting of: a dispersant, a nonionic polymer, an antifoam, and a biocide;
(c) combining the lipophilic phase and aqueous phase to form an oil-in-water emulsion;
(d) combining the oil-in-water emulsion with a solution of at least one polyamine in water to generate microcapsules; and
(e) adding a hydrophobic crystal inhibitor additive after the step of combining the oil-in-water emulsion with the solution of at least one polyamine in water to form the microcapsule suspension formulation.
15. The method according to claim 14 , wherein the lipophilic phase comprises 2-chloro-6-(trichloromethyl)pyridine.
16. The method according to claim 14 , wherein the lipophilic phase comprises between about 75 weight percent and about 90 weight percent 2-chloro-6-(trichloromethyl)pyridine.
17. The method according to claim 14 , wherein the lipophilic phase comprises between about 0.1 weight percent and about 3.00 weight percent of the at least one polymeric ultra-hydrophobe compound.
18. The method according to claim 17 , wherein the lipophilic phase comprises a polybutene.
19. The method according to claim 17 , further comprising the step of:
adding at least one second additive selected from the group consisting of: a dispersant, an antifoam, and a biocide after the step of combining the oil-in-water emulsion with the solution of at least one polyamine in water to form the microcapsule suspension.
20. The method according to claim 14 , wherein the aqueous phase comprises between about 1.0 weight percent and about 4.0 weight percent of a hydrophobic crystal inhibitor additive.
21. The method according to claim 20 , wherein the hydrophobic crystal inhibitor additive is at least one compound selected from the group consisting of: aromatic solvents and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.
22. The method according to claim 14 , wherein the aqueous phase comprises between about 1.0 weight percent and about 10 weight percent nonionic polymer.
23. The method according to claim 22 , wherein the nonionic polymer is a polyvinyl alcohol.
24. The method according to claim 14 , wherein the aqueous phase includes at least one additive selected from the group consisting of: a modified styrene acrylic polymeric surfactant, a nonionic polymer, an aqueous emulsion of polydimethylsiloxane concentrate, xanthan gum, microcrystalline cellulose, carboxymethyl-cellulose sodium, and propylene glycol.
25. The method according to claim 14 , wherein the aqueous phase includes at least one additive selected from the group consisting of: a modified styrene acrylic polymeric surfactant, a nonionic polymer, an aqueous emulsion of polydimethylsiloxane concentrate, xanthan gum, microcrystalline cellulose, and carboxymethyl-cellulose sodium.
26. The method according to claim 14 , wherein the formulation comprises between about 40 weight percent and about 70 weight percent of the aqueous phase.
27. The method according to claim 14 , further comprising the step of: controlling the temperature of the oil-in-water emulsion while mixing the lipophilic phase with the aqueous phase to produce oily globules.
28. The method according to claim 14 , wherein the method further comprises the step of adding to the formulation an agricultural active ingredient selected from the group consisting of: pesticides, arthropodicides, bactericides, fungicides, herbicides, insecticides, miticides, nematicides, fertilizers, dicyandiamide, urease inhibitors, and pesticidal mixtures thereof.