US Patent 11179302 Core-composite shell microcapsules

The invention relates to a method for making a core-composite shell microcapsule slurry for the delivery of hydrophobic active ingredients such as fragrance components of perfume oils. The method includes forming an outer shell by coacervation surrounding an internal phase which contains the hydrophobic active ingredient; and forming an inner shell by interfacial polymerization at the interface between the internal phase and the outer shell. The internal phase contains the hydrophobic active ingredient. The microcapsules are typically incorporated in a consumer product wherein the composite shell prevents the hydrophobic active ingredient from release until desired, generally during use of the consumer product.