Patent ID: 6559217
Filing Date: 2003-05-06
Classification: C08F,C08J

Abstract:
A process for the preparation of monodisperse polymer particles having a mode particle size of at least 120 &mgr;m, the process comprises the steps of:obtaining a first particulate polymer seed material having a first mode particle diameter of no more than 50 &mgr;m; using the first particulate polymer seed material, performing a polymerization to yield a second particulate polymer seed material having a second mode particle diameter greater than the first mode particle diameter; and using the second particulate polymer seed material, performing at least one further polymerization to yield polymer particles having a mode particle size of at least 120 &mgr;m; wherein at least one of the polymerizations comprises the steps of: forming an aqueous dispersion comprising a particulate polymer seed material, an organic compound which has a molecular weight of less than 5000 Daltons and a water solubility of less than 10âˆ’2 g/L at 25Â° C., and a stabilizer; allowing the organic compound to diffuse into the particulate polymer seed material to produce an activated seed material; contacting the activated seed material with a monomer and a polymerization initiator; and effecting polymerization.