Microcapsule composition, method for manufacturing same, agrochemical formulation comprising same and weed control method

A method of producing a microcapsule composition comprising pyroxasulfone and a polyester block copolymer encapsulated therein, wherein the polyester block copolymer has CAS Registry No. 2142005-01-2, a brown powder appearance, a melting temperature of 85° C., oil compatibility with vegetable oil and paraffinic oil, and oil incompatibility with methylated seed oil,

• the method comprising:
• an emulsifying dispersion step of performing high-speed stirring of pyroxasulfone crystal particles, the polyester block copolymer, isocyanate, an oily phase, and an aqueous phase at a peripheral speed of 10,000 to 50,000 mm/s to allow emulsifying dispersion of the oily phase in the aqueous phase, to form emulsion particles of the oily phase, wherein the oily phase is an aromatic hydrocarbon selected from the group consisting of benzene, toluene, xylene, solvent naphtha, alkylnaphthalene and phenylxylylethane and the oily phase formed in the emulsifying dispersion step has a viscosity of 10 to 52 mPa's at 20° C.;
• and
• a membrane formation step of forming a membrane on at least a surface of the emulsion particles of the oily phase formed by the emulsifying dispersion step.