US 12,404,351 B2
Preparation of an aqueous dispersion of occluded polymer particles
James C. Bohling, Lansdale, PA (US); Justin Gimbal, Warminster, PA (US); and Ian D. Robertson, Collegeville, PA (US)
Assigned to Rohm and Haas Company, Collegeville, PA (US); and Dow Global Technologies LLC, Midland, MI (US)
Appl. No. 17/785,072
Filed by Dow Global Technologies LLC, Midland, MI (US); and Rohm and Haas Company, Collegeville, PA (US)
PCT Filed Nov. 19, 2020, PCT No. PCT/US2020/061230
§ 371(c)(1), (2) Date Jun. 14, 2022,
PCT Pub. No. WO2021/126454, PCT Pub. Date Jun. 24, 2021.
Claims priority of provisional application 62/949,471, filed on Dec. 18, 2019.
Prior Publication US 2023/0052817 A1, Feb. 16, 2023
Int. Cl. C08F 2/30 (2006.01); C08F 4/40 (2006.01); C08F 20/12 (2006.01); C08F 220/14 (2006.01); C08F 220/18 (2006.01); C08F 230/02 (2006.01)
CPC C08F 2/30 (2013.01) [C08F 4/40 (2013.01); C08F 20/12 (2013.01); C08F 220/14 (2013.01); C08F 220/1804 (2020.02); C08F 230/02 (2013.01)] 6 Claims
 
1. A process for preparing an aqueous dispersion of multiphase occluded polymer particles comprising the steps of a) contacting, under emulsion polymerization conditions, first monomers and a chain transfer agent to form an aqueous dispersion of first polymer particles having a Tg in the range of from −30° C. to 30° C., wherein the concentration of the chain transfer agent is from 0.5 to 1.5 mole percent based upon the moles of first monomers and the chain transfer agent; then b) contacting the aqueous dispersion of first polymer particles with a second monomer under emulsion polymerization conditions to form an aqueous dispersion of second polymer particles occluded within the first polymer particles, wherein the first monomers comprise from 0.2 to 5 weight percent of a phosphorus acid monomer or a salt thereof, based on the weight of the first monomers; the second monomer comprises at least 90 weight percent methyl methacrylate; and wherein the weight to weight ratio of first monomers to the second monomer is in the range of from greater than 80:20 and less than 95:5.