Patent attributes
A novel method of forming water in oil microcapsules is disclosed. According to the invention microcapsules are obtained by steps comprising dispersing an oil soluble amine modified polyfunctional polyvinyl monomer and an oil soluble bi- or polyfunctional vinyl monomer along with a thermal or UV free radical initiator (optionally included in one or both of the oil or water phases) and an organic acid into an internal phase oil; heating or UV exposing for a time (and temperature) sufficient to oligomerize the amine modified polyfunctional polyvinyl monomer and oil soluble bi- or polyfunctional vinyl monomer forming a pre-polymer. Thereafter the process involves adding to the oil phase oil a water phase comprising a dispersion in water of an anionic emulsifier (and optionally initiator), and adding an emulsifying agent. Emulsifying the water phase into the oil phase (W/O) is controlled through the quantity of water employed. The emulsion is then UV exposed or heated for a time (and temperature) sufficient to decompose the free radical initiators in the oil and/or water phases; thereby forming microcapsule wall material at the interface of the water and oil phases.
