US 12,084,535 B2
Process for preparing waterborne dispersion
Michael Arnoldus Jacobus Schellekens, Echt (NL); Johannes Hendrikus De Bont, Echt (NL); and Gerardus Cornelis Overbeek, Echt (NL)
Assigned to Covestro (Netherlands) B.V., Nieuwegein (NL)
Appl. No. 17/426,799
Filed by COVESTRO (NETHERLANDS) B.V., Nieuwegein (NL)
PCT Filed Jan. 29, 2020, PCT No. PCT/EP2020/052149
§ 371(c)(1), (2) Date Jul. 29, 2021,
PCT Pub. No. WO2020/157121, PCT Pub. Date Aug. 6, 2020.
Claims priority of application No. 19154624 (EP), filed on Jan. 30, 2019.
Prior Publication US 2022/0098353 A1, Mar. 31, 2022
Int. Cl. C08F 2/38 (2006.01); C08F 4/80 (2006.01); C08F 293/00 (2006.01); C09D 133/04 (2006.01); C09D 153/00 (2006.01); C09J 133/04 (2006.01); C09J 153/00 (2006.01)
CPC C08F 293/005 (2013.01) [C08F 2/38 (2013.01); C08F 4/80 (2013.01); C09D 133/04 (2013.01); C09D 153/00 (2013.01); C09J 133/04 (2013.01); C09J 153/00 (2013.01); C08F 2438/03 (2013.01)] 24 Claims
 
1. A process for preparing a waterborne dispersion comprising
(A) amphiphilic block copolymer comprising at least blocks [A] and [B], whereby
block [A] comprises ethylenically unsaturated monomer(s) bearing acid-functional groups (monomer(s) (i)), and
block [B] comprises ethylenically unsaturated monomer(s) different from monomer(s) (i) (monomer(s) (ii)); and
(B) polymer P comprising ethylenically unsaturated monomer(s) different from monomer(s) (i) (monomer(s) (iii)),
whereby the amount of the amphiphilic block copolymer is higher than 0.5 and lower than 50 wt. %, based on the total weight of monomers used to prepare the amphiphilic block copolymer and polymer P, characterized in that the process comprises at least the following steps:
(I) subjecting at least ethylenically unsaturated monomer(s) (i) bearing acid-functional groups to a free-radical polymerization process in an aqueous medium in the presence of a free radical initiator and a cobalt chelate complex to obtain block [A],
(II) subjecting at least ethylenically unsaturated monomer(s) (ii) different from monomer(s) (i) to an emulsion polymerization process in aqueous medium in the presence of block [A] and a free radical initiator, whereby the amount of ethylenically unsaturated monomer(s) (ii) in block [B] is at least 70 wt. %, relative to the total weight amount of monomers used to prepare block [B] and whereby the ethylenically unsaturated monomer(s) (ii) is (are) selected from the group consisting of methacrylic acid esters, dialkyl esters of itaconic acid, methacrylonitrile, α-methyl styrene and any mixture thereof,
(III) subjecting at least ethylenically unsaturated monomer(s) (iii) different from monomer(s) (i) to an emulsion polymerization process in aqueous medium at a pH in the range of from 5 to 10 in the presence of the amphiphilic block copolymer to obtain an amphiphilic block copolymer-polymer P, and the process further comprises deactivating the cobalt chelate complex, which remains from step (I), prior to and/or during step (II).