Particles containing agricultural active ingredients
One or more agricultural active ingredients (such as fungicides or insecticides) are entrapped in polymeric matrixes to form particles having a diameter in the range from about 0.2 to about 200 microns. The particles are applied to soil, to seeds, or to plants and release the active ingredient(s) at a rate sufficiently low to avoid phytoxicity but at a rate sufficiently high to provide effective amounts of the active ingredient(s), preferably throughout the growing period of the plant.
1. A method of producing a solid particle wherein the particle is free of a plasticizer and comprises a triazole fungicide dispersed throughout a solid polymer matrix, the method comprising:
(a) providing a hydrophobic solution comprising the triazole fungicide, a polymer, and a solvent;
(b) mixing the hydrophobic solution and an aqueous medium to produce a dispersion of droplets of the hydrophobic solution in the aqueous medium; and
(c) evaporating the solvent from the dispersion to produce the solid particle which is free of a plasticizer and which comprises the triazole fungicide dispersed throughout the solid polymer matrix.
2. The method of claim 1 wherein the triazole fungicide is selected from the group consisting of bitertanol, bromuconazole, cyproconazole, difenoconazole, epoxiconazole, fenbuconazole, fluquinconazole, flusilazole, flutriafol, hexaconazole, imibenconazole, metconazole, myclobutanil, penconazole, propiconazole, tebuconazole, tetraconazole, triadimefon, triadimenol, and triticonazole.
3. The method of claim 2 wherein the triazole fungicide is selected from the group consisting of cyproconazole, epoxiconazole, tebuconazole, triadimefon, and triadimenol.
4. The method of claim 2 wherein the triazole fungicide is cyproconazole.
5. The method of claim 2 wherein the triazole fungicide is tebuconazole.
6. The method of claim 2 wherein the triazole fungicide is epoxiconazole.
7. The method of claim 2 wherein the triazole fungicide is triadimenol.
8. The method of claim 2 wherein the triazole fungicide is triadimefon.
9. The method of claim 1 wherein the hydrophobic solution further comprises a dispersing agent.
10. The method of claim 1 wherein the aqueous medium comprises a dispersing agent.
11. The method of claim 1 wherein the solvent is a hydrophobic solvent.
12. The method of claim 1 wherein the solvent comprises a compound selected from the group consisting of halogenated hydrocarbons, aromatic compounds, hydrocarbons, ethers, and esters.
13. The method of claim 1 wherein the solvent comprises a compound selected from the group consisting of methylene chloride, ethyl acetate, chloroform, carbon tetrachloride, acetonitrile, diethyl ether, dimethyl ether, acetone, methylethylketone, pentane, hexane, hexanes, heptane, dioxane, ethanol, methanol, pyridine, propanol, 2-propanol, butanol, 2-butanol, t-butyl alcohol, isobutyl alcohol, perchloroethylene, tetrachloroethane, o-xylene, m-xylene, p-xylene, toluene, benzene, mesitylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene.
14. The method of claim 13 wherein the solvent comprises methylene chloride.
15. The method of claim 1 wherein step (c) comprises applying a source of vacuum to the dispersion.
16. The method of claim 1 wherein step (c) comprises applying heat to the dispersion.
17. The method of claim 1 wherein step (c) comprises lyophilizing the dispersion.
18. The method of claim 1 , wherein the polymer matrix comprises a polymer selected from the group consisting of poly(methylmethacrylate), poly(lactic acid), a poly(lactic acid-glycolic acid) copolymer, cellulose acetate butyrate, a poly(styrene), hydroxybutyric acid-hydroxyvaleric acid copolymer, a styrene maleic anhydride copolymer, poly(methylvinyl ether-maleic acid), poly(caprolactone), poly(n-amylmethacrylate), wood rosin, a polyanhydride, a polyorthoester, a poly(cyanoacrylate), poly(dioxanone), ethyl cellulose, a ethyl vinyl acetate polymer, poly(ethylene glycol), poly(vinylpyrrolidone), an acetylated monogylceride, an acetylated digylceride, an acetylated trigylceride, poly(phosphazene), chlorinated natural rubber, a vinyl polymer, polyvinyl chloride, a hydroxyalkylcellulose, polybutadiene, polyurethane, a vinylidene chloride polymer, a styrene-butadiene copolymer, a styrene-acrylic copolymer, an alkylvinylether polymer, a cellulose acetate phthalate, an ethyl vinyl phthalate, cellulose triacetate, a polyanhydride, a polyglutamate, a polyhydroxy butyrate, polyvinyl acetate, a vinyl acetate-ethylene copolymer, a vinyl acetate-vinylpyrrolidone copolymer, an acrylic polymer, an alkyl acrylate polymer, an aryl acrylate polymer, an aryl methacrylate polymer, a poly(caprolactam), an epoxy resin, a polyamine epoxy resin, a polyamide, a polyvinyl alcohol polymer, a polyalkyd resin, a phenolic resin, an abietic acid resin, a silicone, a polyalkylene oxide, and a polyester.
19. The method of claim 1 , wherein the mean diameter of said particle is in the range of from about 0.1 microns to about 200 microns.
20. The method of claim 1 , wherein the mean diameter of said particle is in the range of from about 0.2 microns to about 100 microns.
21. The method of claim 1 , wherein the mean diameter of said particle is in the range of from about 0.5 microns to about 50 microns.
22. The method of claim 1 , further comprising producing a fungicidal composition by intermixing said particles with an agricultural adjuvant.
23. The method of claim 22 , wherein the fungicidal composition is in the form of a liquid suspension.
24. The method of claim 22 , wherein the fungicidal composition is in the form of a wettable powder.
25. The method of claim 22 , wherein the fungicidal composition is in the form of a granule.
26. The method of claim 25 , wherein the granule is a water-dispersible granule.
27. The method of claim 22 , wherein the agricultural adjuvant comprises a dispersant.
28. The method of claim 22 , wherein the agricultural adjuvant comprises a diluent.