| abstract |
This invention relates to a process for encapsulation, and particularly to the production of small or minute capsules constituted by a skin or thin wall of polymeric material, e.g., polyurea, polyamide, polysulfonamide, polyester, polycarbonate, or polyurethane, which involves first providing an aqueous solution (continuous phase liquid) containing an emulsifier selected from the group consisting of sulfonated napthalene formaldehyde condensates, sulfonated polystyrenes derivatives and functionalized oligomers. A discontinuous, immiscible or organic) phase liquid containing a water-immiscible material which is the material to be encapsulated, plus a first shell wall component; is dispersed in the aqueous liquid to form an oil-in-water emulsion. The second shell wall component is added to the oil-in-water emulsion whereupon the first shell wall component reacts with the second shell wall component to form a solid polycondensate shell wall about the material to be encapsulated. The capsules formed may be directly used as in the form of an aqueous suspension. |