Process for microencapsulation of oils with colour coreactants dissolved therein, and microcapsules produced according to the process

摘要

A process is described for micro-encapsulating oils with colour coreactants of colour reaction systems dissolved therein, the capsule sheath having been obtained by the reaction of a water-soluble melamine-formaldehyde precondensate with a water-soluble polymer in an aqueous emulsion in the form of an oil-in-water dispersion. This process is characterised in that the aqueous stabilising emulsion contains a cation-active dextrin derivative of the following formula (I): <IMAGE> in which: the radicals R1 to R10, each singly, are a hydrogen atom, an unsubstituted or substituted lower alkyl radical, a substituted or unsubstituted aralkyl radical, the alkyl substituent having the abovementioned meaning, or a substituted or unsubstituted aryl radical, n is an integer from 1 to 4, m is 0.1 to 3 and X<-> is an inorganic or organic acid radical. This dextrin derivative results in outstanding stabilisation of the reaction medium. Excellent capsules can be obtained without agglomeration.