MICROCAPSULE FORMULATIONS OF AGRICULTURAL CHEMICALS

摘要

A composition comprising highly concentrated microencapsules containing pesticides having a skin or shell wall of polyurea, polyamide, polysulfonamide, polyester, polycarbonate of polyurethane suspended in an aqueous liquid containing an emulsifier which is a random co-or terpolymer of vinylpyrrolidone that will form a stable oil-in-water emulsion under the conditions described and a process for preparing said composition by mixing a liquid phase water immiscible pesticide to be encapsulated with a first shell wall component in the aqueous liquid to form an oil-in-water emulsion and then adding a second shell wall component to the emulsion causing the first shell wall component to react with the second wall component to form a skin of polycondensate shell wall about the pesticide to be encapsulated or alternatively when the first shell wall component is an isocyanate or mixture thereof allowing the first shell component in the emulsion to hydrolyze to form amine groups which react with residual isocyanate to generate a shell wall of polyurea which suspensions may be used directly as an aqueous suspension or dried to form water dispersible formulations of microcapsules.