Patent ID: 8696955
Filing Date: 2014-04-15
Classification: C08F,C08J,Y10T

Abstract:
1. A method for making a hollow polymer particle having a single, substantially circular opening in its surface, comprising: (a) suspending solid polymer particles in a first solvent to provide first-solvent-suspended particles; (b) swelling the first-solvent-suspended particles with a second solvent to provide second-solvent-swollen particles; (c) cooling the second-solvent-swollen particles below the freezing temperature of the second solvent, creating a void within each particle to provide second-solvent-containing particles having frozen second solvent; and (d) warming the second-solvent-containing particles having frozen solvent, such that the second solvent escapes from the particles resulting in the formation of a single opening in the surface of each particle to provide a hollow polymer particle having a single, substantially circular opening in its surface.