Patent attributes
Microcapsules encapsulating oily core materials have a shell material of hybrid polyurea and poly(beta-amino esters) (PU/PBAE). The microcapsules may have a single shell of hybrid PU/PBAE, dual shells including hybrid PU/PBAE in an inner shell and PBAE in an outer shell crosslinked and deposited to the inner shell, or multiple shells including PU in an inner shell, hybrid PU/PBAE in a transitioning shell, and PBAE in an outer shell. Formation of the microcapsules includes polymerization between multifunctional amine and multifunctional acrylate to produce a water soluble PBAE; polymerization between polyisocyanate in oil phase and multifunctional amine in aqueous solution to produce PU microcapsule, polymerization between polyisocyanate and the amine moiety of PBAE prepolymer to produce hybrid PU/PBAE microcapsule wall; and polymerization between multifunctional acrylate and primary or secondary amine moiety of the PBAE prepolymer to form a PBAE outer shell.
