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US 8,476,193 B2Granted
Stable oil-in-water emulsions
AssigneeDow AgroSciences LLC
InventorsFranklin N. Keeney, Mei Li
Life of this patent
Estimating the term…
Abstract
Interaction of cloquintocet mexyl in the discontinuous oil phase with water in the continuous aqueous phase of an oil-in-water emulsion, which can lead to cloquintocet mexyl hydrate formation, crystal formation and Ostwald ripening, is minimized by the use of specific surfactants and solvents which provide enhanced stability to the emulsion.
Claims22
A stable oil-in-water emulsion which comprises:
- a) a discontinuous oil phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 800 g/L of oil solvent, from about 1 g/L to about 200 g/L of emulsion template solvent and from about 1 g/L to about 200 g/L of cloquintocet mexyl;
- b) a continuous aqueous phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 700 g/L of water;
- c) an emulsifying surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L;
- d) a polymeric dispersing surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L;
- and
- e) optionally, other inert formulation ingredients;
- wherein the oil-in-water emulsion is stable for at least 6 weeks at 40° C. as indicated by the absence of crystals due to cloquintocet-mexyl hydrate formation as determined by examination with a microscope using polarized light.
4 more elements
A stable oil-in-water emulsion which consists essentially of:
- a) a discontinuous oil phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 800 g/L of oil solvent, from about 1 g/L to about 200 g/L of emulsion template solvent and from about 1 g/L to about 200 g/L of cloquintocet mexyl;
- b) a continuous aqueous phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 700 g/L of water;
- c) an emulsifying surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L;
- and
- d) a polymeric dispersing surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L;
- wherein the oil-in-water emulsion is stable for at least 6 weeks at 40° C. as indicated by the absence of crystals due to cloquintocet-mexyl hydrate formation as determined by examination with a microscope using polarized.
3 more elements
A stable oil-in-water emulsion which comprises:
- a) a discontinuous oil phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 800 g/L of oil solvent, from about 1 g/L to about 200 g/L of emulsion template solvent and from about 1 g/L to about 200 g/L of cloquintocet mexyl;
- b) a continuous aqueous phase comprising, with respect to the oil-in-water emulsion, from about 200 g/L to about 700 g/L of water;
- c) an emulsifying surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L, wherein the emulsifying surfactant
- (i) a mixture 90% sorbitan trioleate with 20 ethylene oxide units and 10% sorbitan trioleate,
- (ii) a polyethylene glycol ether of a C11-C13 mixture of alcohols, or
- (iii) an n-butyl alcohol initiated EO-PO block copolymer;
- d) a polymeric dispersing surfactant comprising, with respect to the oil-in-water emulsion, from about 1 g/L to about 100 g/L, wherein the polymeric dispersing surfactant is:
- (i) a polyvinyl alcohol resin having a degree of hydrolysis of about 86 to 89 percent;
- (ii) an ABA block copolymer having a hydrophilic portion of polyethylene oxide and a hydrophobic portion of 12-hydroxystearic acid;
- (iii) a methyl methacrylate graft copolymer;
- or
- (iv) an alkyd polyethylene oxide resin;
- e) propylene glycol;
- and
- f) optionally, other inert formulation ingredients.
12 more elements
Dependencies are inferred from the claim text.