US 11,851,536 B2
Precipitation process for preparing polystyrene microparticles
Valerie M. Farrugia, Oakville (CA); Edward G. Zwartz, Mississauga (CA); and Sandra J. Gardner, Oakville (CA)
Assigned to Xerox Corporation, Norwalk, CT (US)
Filed by Xerox Corporation, Norwalk, CT (US)
Filed on Oct. 2, 2018, as Appl. No. 16/149,320.
Prior Publication US 2020/0102427 A1, Apr. 2, 2020
Int. Cl. C08J 3/14 (2006.01); B29C 64/153 (2017.01); C08F 12/08 (2006.01); B29K 25/00 (2006.01); B33Y 70/10 (2020.01)
CPC C08J 3/14 (2013.01) [B29C 64/153 (2017.08); C08F 12/08 (2013.01); B29K 2025/06 (2013.01); B33Y 70/10 (2020.01); C08F 2500/01 (2013.01); C08F 2500/05 (2013.01); C08F 2500/24 (2013.01); C08J 2325/06 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A process comprising:
combining polystyrene, wherein the polystyrene is a bimodal molecular weight distribution polystyrene, wherein the polystyrene has a weight average molecular weight of from about 40,000 to about 100,000 Daltons, and a first solvent to form a polystyrene solution;
heating the polystyrene solution;
adding a second solvent to the polystyrene solution with optional stirring whereby polystyrene microparticles are formed via microprecipitation;
optionally, cooling the formed polystyrene microparticles in solution; and
optionally, removing the first solvent and second solvent.