TIME LIMIT COLLAPSING-TYPE MULTILAYER COVERED AGRICULTURAL CHEMICAL GRANULE

摘要

PROBLEM TO BE SOLVED: To provide a time limit collapsing-type multilayer covered agricultural chemical granule releasing an active component after passing a prescribed period after the application by re-covering a granule composed of agricultural chemicals and a thermoplastic resin onto a water-swelling substance by using a coated material composed of a specific (co)polymer as a main component of a coating film. ;SOLUTION: This time limit collapsing-type multilayer covered agricultural chemical granule is obtained by following double-coating process: the surface of a granule mainly composed of a water-swelling substance is covered with a composition composed of an agricultural chemicals active component and a thermoplastic resin (preferably the agricultural chemicals active component is added into the water-swelling substance), then the surface of the resultant agricultural chemicals granule is further covered with a covering material composed of an olefin polymer or its copolymer. As the water-swelling substance, bentonite, starch and a water-absorptive polymer are used. As the thermoplastic resin, a waxy substance, a biodegradable polymer or a water-soluble polymer is used. Preferably, a surfactant and/or a water- insoluble or a hardly water-soluble inorganic powder is dispersed and contained in the agricultural chemicals active component and the thermoplastic resin in the granule. By using this granule, the agricultural chemicals can be applied simultaneously to transplantation of paddy rice seedlings.;COPYRIGHT: (C)1997,JPO