| 摘要 |
A variety of materials, e.g., colorants, agricultural chemicals, pharmaceuticals, etc., are conveniently microencapsulated within polyurea skin membranes by interfacial polyaddition, by emulsifying a polyisocyanato hydrophobic liquid in an essentially aqueous medium, said polyisocyanato hydrophobic liquid comprising dissolved material to be microencapsulated, an aliphatic diisocyanate (i) and an isocyanurate ring trimer (ii) of an aliphatic diisocyanate, the ratio by weight of said diisocyanate (i) to said trimer (ii) ranging from 0.05/1 to 0.70/1, and then interfacially reacting a polyamine therewith. The resulting suspension of microcapsules is well adapted, e.g., for the production of carbonless papers. |
