| 摘要 |
PURPOSE:To improve protective capacity for a core material and to improve also safety for human body by mixing an aq. dispersion of microcapsules having a shell comprising polyvinyl alcohol with an aldehyde having a specified solubility, and allowing the shell to react with the aldehyde in acidic condition. CONSTITUTION:An aq. dispersion contg. microcapsules having a shell consisting of polyvinyl alcohol and an aq. soln. contg. 8-50wt.% electrolyte, is mixed with an aldehyde having >=10% solubility in water at 20 deg.C. Thus, the shell of microcapsules are improved by causing a reaction in acidic condition. Preferred polyvinyl alcohol is that contg. 50wt.% polyvinyl alcohol component in the polymer. Preferred amt. of the aldehyde to be added is 0.3-10times by weight of the polyvinyl alcohol, and the reaction is preferred to be carried out at 0.5-4.5pH. |
