PROCESS FOR MICROENCAPSULATING HYDROPHOBIC OILS, THE MICROCAPSULES OBTAINED AND THE USE THEREOF

摘要

1. Process for microencapsulating hydrophobic oils with colour reactants of colour reaction systems dissolved therein, a cationized melamine/formaldehyde precondensate being precipitated in ultra-fine suspension from its acid aqueous solution, accompanied by vigorous stirring and by modifying the solubility conditions, said suspension is mixed under vigorous stirring with a hydrophobic oil containing the colour reactants in dissolved form, the oil-in-water dispersion obtained is acid-adjusted and an aqueous solution of a water-soluble, non-ionic melamine/formaldehyde precondensate is added, accompanied by stirring, for forming the microcapsule envelope, characterized in that, for stabilizing the oil-in-water dispersion, the pH-value of the acid aqueous solution of a cationized melamine/formaldehyde precondensate which, in the weak acid, neutral and alkaline aqueous use range is present in insoluble cationizable form, is raised in the absence of water-soluble organic polymers by the addition of Bronsted bases and accompanied by vigorous stirring to such an extent that the cationizable melamine/formaldehyde precondensate is precipitated in ultra-fine suspension as a result of the modified solubility conditions.