PURPOSE:The titled capsule preparation that is formed by using a solution of ethoprophos in a vegetable oil as the core component and aminoplast as the coating and by ageing the resultant microcaplules under specific conditions, thus being practically applicable as a nematocide with reduced toxicity. CONSTITUTION:Ethoprophos and a vegetable oil are mixed at a 7/3-2/8 weight ratio and the mixture is used as the core component. In the meantime, a urine- formaldehyde prepolymer and/or melamine formaldehyde prepolymer condensate is used as the microcapsule coating agent. The resultant microcapsules are aged to give the objective capsule preparation. Ageing is conducted by adjusting the pH of the microcapsule slurry to 3.5-7, combining with 0.5-2wt% of a dispersant and standing them at 40-60 deg.C for 60-80hr so that a microcapsule containing 30mg of ethoprophos elutes less than 10% of ethoprophos after agitation in 700ml of water for 1hr. The microcapsules may be in the form of a powder or granules.
展开▼
