The present invention is intended to provide a technique for delaying timing for releasing an agricultural chemical compound from a microcapsule formulation which contains the agricultural chemical compound in at least one compound from the group of consisting of ester compounds and aromatic hydrocarbon compounds. A microcapsule formulation produced by the following process is more effectively controlled in release of an agricultural chemical compound therefrom, than any of the existing microcapsule formulations. This production process comprises the steps of(1) maintaining a mixture of an agricultural chemical compound (a), at least one compound (b) selected from the group consisting of ester compounds and aromatic hydrocarbon compounds, except for the compounds of the formula (I):(wherein X represents -CH2-CH2- or -CH=CH- R1 represents a C1-C4 alkyl group and R2 represents a C1-C4 alkyl group), and a polyisocyanate (c) at a temperature of from 20 to 80℃ for 3 hours or longer(2) adding the resulting mixture to an aqueous solution which contains a polyol or a polyamine, to form liquid droplets of the mixture in the aqueous solution(3) forming coatings of a polyurethane or a polyurea around the liquid droplets.本發明係欲提供一種用於延遲農業化學化合物從微膠囊劑型釋出之時間點的技術,該微膠囊劑型在由酯化合物及芳香族烴化合物所組成群組之至少一種化合物中含有該農業化學化合物。相較於現行微膠囊劑型,藉由下列方法製備之微膠囊劑型更有效率地控制農業化學化合物從該微膠囊劑型之釋出。該製備方法包括下列步驟:(1)將農業化學化合物(a)、選自由酯化合物及芳香族烴化合物所組成群組之至少一種化合物(b)[排除式(I)之化合物:(式中,X表示-CH2-CH2-或-CH=CH-;R1表示C1-C4烷基;以及R2表示C1-C4烷基)]、以及聚異氰酸酯(c)的混合物,在20至80℃維持3小時或更久;(2)將所得混合物加入含有多元醇或多胺的水溶液中,以在該水溶液中形成混合物的液態微滴;以及(3)在該液態微滴的周圍形成聚胺酯或聚脲的包膜。
