| 摘要 |
PURPOSE:To obtain microcapsules extremely high in industrial effect by a method wherein a substance to be capsulized is emulsified or dispersed into a mixture of polyvinyl alcohol and zirconium chloride, regardless of whether it is of hydrophilic or hydrophobic property, and the resulting product is sprayed or dropped into an alkaline atmosphere. CONSTITUTION:A microcapsule is obtained by a method wherein a substance to be capsulized such as medicine is emulsified or dispersed in an aq. solution of a mixture intended to be formed into a diaphragm and contg. polyvinyl alcohol(PVA) and/or its derivative and zirconium chloride such as zirconium tetrachloride and the resulting product of the aforesaid emulsification or dispersion is sprayed and dried in an alkaline atmosphere or dropped into an aq. alkali solution. When the PVA and the zirconium chloride are made up, the hydrophilic group of the PVA and the zirconium ions form a stable complex and the zirconium functions as a cross-linking agent between the PVA molecules by treating and drying the alkali to form a cross-linked structure. Furthermore, the zirconium ions are combined with the carbon atoms of the PVA by the oxygen atoms to exert a heat resisting, water resisting and clarifying effect due to insolubility. |
