| abstract |
A microencapsulation of varied substances such as aromatic agents, colorings, inks, chemical reactives, pharmaceutical and phytosanitary products, fireproof products, glues, finely dispersed in an aqueous phase, in order to obtain microcapsules that are simulaneously isodiametrical and with regularized diameters, which consists in placing face to place an aqueous solution of polymers and/or hydrosoluble copolymers including at least one of the chemical functions belonging to the group constituted by the radicles -COOH, -OH, -CONH2, -COHNR, -CONRR', -NH2, NHR and -NRR', constituting the material of the capsule containing shell, and a solution of substances to be coated in at least one hydrophobic organic solvent, density close to 1, then submitting the liquid medium thus constituted to a mechanical shearing action corresponding to a shearing coefficient included between 8,000 second-1 and 70,000 second-1, while the medium is maintained at a temperature between 15 DEG C. and 85 DEG C. The isodiametrical microcapsules with regularized diameters thus obtained have a particularly attractive application in the manufacturing of registration and transfer materials with paper support by both coating process and impression process, such as Offset. |