ENCAPSULATION BY INTERFACIAL POLYCONDENSATION OF POLYMETHYLENE POLYPHENYLISOCYANATE WITH A POLY- FUNCTIONAL AMINE IN PRESENCE OF A LIGNIN SULFONATE EMULSIFIER

摘要

AG-1288ENCAPSULATION BY INTERFACIAL POLYCONDENSATIONABSTRACT OF THE DISCLOSUREThis invention relates to a process forencapsulation, and particularly to the production of smallor minute capsules constituted by a skin or thin wall ofpolyurea, which involves bringing together an aqueous phasecontaining a lignin sulfonate emulsifier and a water-immiscible phase containing a water-immiscible material, thematerial to be encapsulated, plus polymethylenepolyphenylisocyanate, dispersing the water-immiscible phasein the aqueous phase followed by addition of apolyfunctional amine. Polymethylene polyphenylisocyanatereacts with the amine to form a solid polyurea shell wallabout the encapsulated material. The capsules formed may bedirectly used as aqueous suspensions.