Mikropartikel, enthaltend einen Wirkstoff und ein polymeres Kapselwandmaterial, ein Verfahren zu deren Herstellung und deren Verwendung

Microparticles comprise a core of a hydrophobic material, which is waxy at room temperature, containing an active agent as capsule contents. The core is (partly) covered by a polymeric capsule wall material. Also claimed is a method of making the microparticles, by (a) preparing an aqueous solution containing a prepolymer for the wall material, preferably in a concentration of 3-50 g/100 g water; (b) melting and homogenising the agent and wax; and (c) adding the melt from (b) to the solution from (a) at 20-95 deg. C, with the solution above the temperature of the melt; and mixing with shear. USE - The microparticles are used for combating plant, food and hygiene pests, animal parasites and weeds, and are applied as an aqueous suspension, or are used to prepared attractants; and for releasing fragrances and ethereal oils, when applied in aqueous solution, suspensions or dispersion, or in lacquer or paint (all claimed). The microparticles are useful for preparing plant protective agents for agriculture and forestry, hygiene products and products for the food, packaging, building and cosmetics industries. ADVANTAGE - The microparticles allow controlled release of the agent, especially for long-term application. The wax matrix controls diffusion at temperatures below its melting range, which can be varied to suit the application. With a wax that sets at temperatures of cool nights and mornings, no agent is released when pest activity is very low.