Process for preparing microcapsules in a liquid vehicle

Claim 1

A process for preparing microcapsules in a liquid vehicle, comprising the following steps: (1) dissolution of a membrane-forming cellulosic polymer in a solvent which is the microencapsulation vehicle; (2) addition of cores of a substance to be microencapsulated to said solution; (3) formation of a coacervate by adding a substance adapted to cause phase separation; (4) deposition of the coacervate, forming a continuous coating of polymer around the cores of the substance; and (5) solidification of the polymer; the improvement comprising the fact that the membrane-forming cellulosic polymer is a cellulose phthalate having the following chemical structure: ##STR2## wherein R is hydrogen or a methyl, hydroxypropyl, carboxybenzoyl, 2-(2-carboxybenzoyl)propyl, or acetyl group, at least one R being always carboxybenzoyl, that the polymer is dissolved in aqueous or buffer solution, and that the phase separator is a substance causing phase separation of the cellulose phthalate from aqueous solution at a pH≧5.