摘要 |
A process for the production of a hot melt coating composition containing microcapsules. The process comprises the steps of preparing a dispersion of substantially discrete microcapsules in a volatile solvent continuous phase. A hot melt suspending medium is prepared, the hot melt suspending medium having a melting point of from about 50 DEG C. to about 140 DEG C. and a melting point range of less than about 15 DEG C., the hot melt suspending medium being in a fluid state. The dispersion of substantially discrete microcapsules in a volatile solvent is then mixed with the fluid hot melt suspending medium with turbulent agitation to form an intimate mixture of the dispersion of microcapsules and the hot melt suspending medium. Heat and a vacuum are applied to the mixture, while maintaining the agitation, until the volatile solvent is substantially removed from the mixture to form a dispersion of substantially discrete microcapsules in the liquid hot melt suspending medium. The heat is applied at a rate sufficient to maintain the mixture at a temperature above the melting point of the hot melt suspending medium, the temperature also being above the boiling point of water at the vacuum level. |