Process to prepare microencapsulated formulations
AssigneeFMC Corporation
InventorWenhua W. Wang
Life of this patent
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Abstract
Provided is a method of encapsulating a chemical agent comprising: (a) combining particles of a chemical agent and an encapsulation effective amount of a first encapsulating agent in an aqueous solvent and (b), converting the first encapsulating agent to a polymer to form encapsulated particles of the chemical agent.
Claims4
A composition comprising a suspension of particles of a chemical agent in an aqueous solvent wherein the particles are encapsulating agent selected from the group consisting of polyanhydrides, and acids, salts, and esters thereof;
- polysaccharides;
- polymers of acrylic acids;
- copolymers of acrylic acid;
- polymers of acrylamide;
- copolymers of acrylamide;
- acrylic polymers and copolymers;
- hydrophobically-modified polyacrylic acids;
- polymers formed from simultaneous or sequential hydrolysis and neutralization of styrene maleic anhydride copolymers;
- the ammonium salt of the amic acid derived from styrene maleic anhydride copolymer;
- poly(methyl vinyl ether-co-maleic anhydride;
- N-methylacrylamide;
- (vinyl chloride/vinyl acetate/hydroxyl acrylate) copolymer;
- and polyisocyanates;
- and the encapsulated particles are coated with a second encapsulating agent selected from the group consisting of a formaldehyde copolymer, a polyacrylamide, and a phenoxy resins.
A composition comprising a suspension of particles of a solid pesticide in an aqueous solvent wherein the particles are encapsulated in a first encapsulating agent;
- the first encapsulating agent is an ammonium salt of a polymeric amic acid;
- the polymeric amic acid is derived from a styrene-maleic anhydride copolymer;
- the encapsulation of the particles has been effected by changing the pH of the aqueous solvent to a about 6 to precipitate the ammonium salt of the polymeric amic acid;
- and the encapsulated particles are coated with a second encapsulating agent selected from the group consisting of a formaldehyde copolymer, a polyacrylamide, and a phenoxy resins.
A composition comprising a suspension of particles of a solid pesticide in an aqueous solvent wherein the particles are encapsulated in a first encapsulating agent;
- the first encapsulating agent is an ammonium salt of a polymeric amic acid;
- the polymeric amic acid is derived from a styrene-maleic anhydride copolymer;
- the encapsulation of the particles has been effected by changing the pH of the aqueous solvent to a about 6 to precipitate the ammonium salt of the polymeric amic acid;
- and the encapsulated particles are coated with a second encapsulating agent selected from the group consisting of a urea-formaldehyde resin, a melamine-formaldehyde resin, a phenol-formaldehyde resin, resorcinol-formaldehyde, butylated urea/formaldehyde, a glycoluril-formaldehyde resin, and methylolacrylamide.
Dependencies are inferred from the claim text.