| 摘要 |
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 which is a water soluble, alkylated polyvinyl pyrrolidone polymer which will form a stable oil-in-water emulsion under the process conditions described herein. 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. |
