CPC C08F 220/1804 (2020.02) [C08F 2/22 (2013.01); C08F 220/06 (2013.01); C08F 220/14 (2013.01); C08F 230/08 (2013.01); C08F 230/085 (2020.02); C07F 7/0879 (2013.01); C08F 2800/20 (2013.01)] | 6 Claims |
1. A method of preparing an aqueous dispersion of acrylate-siloxane copolymer particles comprising the steps of:
1) adding a first portion of an aqueous monomer emulsion into a stirred vessel containing water and a surfactant and heating the contents of the vessel to a temperature in the range of from 80° C. to 95° C.; then
2) adding a first portion of an initiator to the vessel to form, over time, an aqueous dispersion of seed polymer particles; then
2) gradually adding a second portion of the aqueous monomer emulsion and a second portion of the initiator to the vessel;
4) maintaining the temperature in the range of from 80° C. to 95° C. for a sufficient time to achieve substantially complete conversion of the monomers to polymer particles comprising structural units of the monomers; then
5) adding a redox initiator package to the vessel;
wherein the monomer emulsion comprises, based on the weight of monomers, a) from 40 to 98.8 weight percent of an acrylate monomer; b) from 0.1 to 5 weight percent of an acid monomer; and c) from 1 to 59.8 weight percent of a siloxane acrylate monomer of formula I:
![]() where R is H or CH3;
R1 is H or CH3; and
each R2 is independently CH3 or O—Si(CH3)3;
Y is —CH2— or —CH2CH2—; and
x is 0 or 1;
with the proviso that when x is 1, R1 is H; when Y is —CH2—, R1 is H; and when Y is —CH2CH2—, R1 is CH3 and x is 0.
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