Insecticidal compsn. comprising HPA-polymer alloy - giving selective and delayed release of insecticide such as permethrin

摘要

An insecticidal compsn. has at least one water-soluble or water-emulsifiable, insecticidal cpd. incorporated in a granule of HPA polymer alloy which does not swell substantially in water of pH up to 7 but which swells in water of pH 8 or more. These are disclosed in Netherlands Patent Application No. 79.08799 and are composed of (a) one or more (co)-polymers having anhydride gps. and a MW of more than 10 power 4 and (b) one or more (co)-polymers having gps. that react with H atoms and having a MW of at least 10 power 4. A pref. alloy contains 30 wt% polystyrene/maleic anhydride and 70 wt% polyvinyl acetate.