Patent ID: 6340653
Filing Date: 2002-01-22
Classification: A01N

Abstract:
Capsules capable of controlled release of encapsulated organic material comprising 2-chloro-N-(ethoxymethyl)-6â€²-ethyl-o-acetololuidide herbicide enclosed in a polyurea capsule produced by the process comprising encapsulating water-immiscible material within discrete capsules of polyurea without addition of a second reactant, whereby hydrolysis of an isocyanate monomer to form an amine takes place which in turn reacts with another isocyanate monomer to form polyurea, which comprises the steps of: a) providing, at room temperature, a dispersion of (i) a water-immiscible phase comprising the herbicide and an organic polyisocyanate in (ii) an aqueous phase comprising a solution of water, a surfactant and a protective colloid; and b) heating and maintaining said dispersion in a temperature range from about 40Â° C. to about 90Â° C., whereupon said herbicide is encapsulated within discrete polyurea capsular enclosures.