Patent ID: 8715544

Claim:
A process for forming a population of microcapsules comprising a liquid hydrophilic core material and a wall material at least partially surrounding the core material, the microcapsule population being formed by: providing a hydrophilic liquid core material; providing an oil continuous phase which is low boiling and preferably nonflammable, the oil continuous phase comprising one or more of an organic oil material with chain length up to about 42 carbons; dividing the oil continuous phase into oil 1 and oil 2; dispersing into oil 1 an initiator; dispersing into oil 2 a multifunctional acrylate or methacrylate monomer or oligomer, and an oil soluble or dispersible monofunctional amine acrylate or monofunctional amine methacrylate, and an acid; combining oil 1 and oil 2; forming a mixture by dispersing the liquid hydrophilic material into the oil continuous phase; optionally adding a surfactant; emulsifying the mixture by subjecting the mixture to high shear agitation; heating the mixture for a time sufficient to enable the monofunctional amine acrylate or monofunctional amine methacrylate and the multifunctional acrylate or methacrylate to form a cationic prepolymer which migrates to the liquid hydrophilic material, thereby forming prepolymers adhered to and surrounding the hydrophilic core material, wherein the acid and monofunctional amine acrylate or monofunctional amine methacrylate have a molar proportion of from 3:1 to 1:3.