Process for the preparation of pressure resistant microcapsules containing an outer polyamide wall and an inner structure of polyurethane-polyurea

摘要

What are disclosed are pressure-resistant microcapsules comprising a polyamide shell having therein a structural mass of a polyurethane-polyurea polymer and an encapsulated water-immiscible liquid phase, and methods for making the same by dispersing a water-immiscible liquid phase in an aqueous phase and subsequently or simultaneously admixing therewith an aqueous solution of a diamine or polyamine, said dispersed phase comprising a polyamide forming acid compound, diisocyanate or polyisocyanate or a prepolymer thereof, and an inert organic aprotic hydrophilizing agent.