Encapsulation of herbicides to reduce crop injury
AssigneeMonsanto Technology LLC
InventorsWilliam ABRAHAM, David Z. BECHER, Brett H. BUSSLER, Amanda C. HERR, S. Douglas PROSCH
Life of this patent
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Abstract
Methods of reducing injury to crop foliage and achieving weed control using encapsulated acetamide herbicides are described. Herbicidal microcapsules comprising herbicide core material and a shell wall encapsulating the core material are also described. The microcapsules provide reduced crop injury through controlled herbicide release.
Claims23
A particulate microencapsulated acetamide herbicide comprising:
- a water-immiscible core material comprising the acetamide herbicide and
- a microcapsule having a shell wall comprising a polyurea, the microcapsule containing the core material,
- wherein the shell wall is formed in a polymerization medium by a polymerization reaction between a polyisocyanate component comprising a polyisocyanate or mixture of polyisocyanates and a polyamine component comprising a polyamine or mixture of polyamines to form the polyurea,
- wherein the ratio of amine molar equivalents contained in the polyamine component to isocyanate molar equivalents contained in the polyisocyanate component is at least 1.1:1, and
- wherein a population of the microcapsules has a mean particle size of at least about 7 μm.
-22. (canceled)
A particulate microencapsulated acetamide herbicide comprising:
- a water-immiscible core material comprising the acetamide herbicide and
- a microcapsule having a shell wall comprising a polyurea, the microcapsule containing the core material,
- wherein the shell wall is formed in a polymerization medium by a polymerization reaction between a polyisocyanate component comprising a polyisocyanate or mixture of polyisocyanates and a polyamine component consisting essentially of a principal polyamine to form the polyurea, and
- wherein a population of the microcapsules has a mean particle size of at least about 7 μm.
-45. (canceled)
A particulate microencapsulated acetamide herbicide comprising:
- a water-immiscible core material comprising the acetamide herbicide and
- a microcapsule having a shell wall comprising a polyurea, the microcapsule containing the core material,
- wherein the shell wall is formed in a polymerization medium by a polymerization reaction between a polyisocyanate component comprising a polyisocyanate or mixture of polyisocyanates and a polyamine component comprising a polyamine or mixture of polyamines to form the polyurea,
- wherein a population of the microcapsules has a mean particle size of at least about 7 μm, and
- wherein the shell wall is of limited permeability, and the nature and composition of said shell wall and encapsulated acetamide is such that, when an aqueous slurry consisting of 1% by weight of the encapsulated acetamide herbicide in an aqueous medium consisting of deionized water is subjected to agitation at a rate sufficient to maintain the particles in suspension without mechanical rupturing, the acetamide content of the aqueous medium remains less than 100 ppm after agitation for 6 hours at 25° C., and less than 150 ppm acetamide after agitation for 24 hours at 25° C.
-193. (canceled)
Dependencies are inferred from the claim text.