PREPARATION OF PH-RESPONSIVE MICROCAPSULE

摘要

PURPOSE:To obtain a microcapsule releasing a core substance in a neutral or acidic aqueous solution, by dispersing the core substance in a solvent having a specific copolymer dissolved therein and further dispersing the prepared dispersion throughtout a solvent mixture consisting of an oil component and a dispersing solvent. CONSTITUTION:A copolymer is prepared from at least one basic monomer represented by formula (wherein R is hydrogen or a methyl group and R<1> and R<2> are an 1-3C alkyl group), at least one water-insoluble or hardly water-soluble monomer and at least one water-soluble monomer. A core substance is dispersed in the dispersing solvent in which this copolymer was dissolved and the obtained dispersion is further dispersed in a solvent mixture consisting of an oil component and a dispersing solvent and the dispersing solvent is subsequently removed to prepare a pH-responsive microcapsule. This microcapsule is insoluble in an alkali aqueous solution but dissolved in a neutral or acidic aqueous solution to release the core substance.