公开(公告)号：WO2021018767A1

公开(公告)日：2021-02-04

申请号：PCT/EP2020/070942

申请日：2020-07-24

Applicant: BASF SE

Inventor： MOLLAT DU JOURDIN, Xavier ,  LESWIN, Joost ,  REINSCH, Michaela ,  SPECHT, Nicole ,  EINHORN-RECH, Janine ,  DIMMER, Joerg Alexander ,  PACHE, Rainer ,  GATTERMAYER, Jochen ,  DENU, Hans-Juergen

IPC: C08F2/22 ,  C08F2/38 ,  C08L33/04 ,  C08L33/06 ,  C09D5/00 ,  C09D133/00

Abstract: The present application relates to a process for producing an aqueous polymer dispersion of polymerized ethylenically unsaturated monomers M by a multistage aqueous radical emulsion polymerization comprising a first aqueous radical emulsion polymerization step of a first monomer composition M.a and subsequently a further aqueous radical emulsion polymerization step of a second monomer composition M.b. The present application also relates to aqueous polymer dispersions obtainable by such a process and to the use thereof, in particular as a binder in coating compositions. The process comprises a multistage aqueous radical emulsion polymerization of ethylenically unsaturated monomers M, comprising a) at least one non-ionic, monoethylenically unsaturated monomer M1 having a solubility in deionized water of at most 60 g/L at 25°C and 1 bar, b) at least one monoethylenically unsaturated monomer M2 selected from monomers having an acid group and their salts, and c) optionally one or more ethylenically unsaturated monomers M3, which are different from the monomers M1 and M2, where the process comprises i) a first step of an aqueous radical emulsion polymerization of a first monomer composition M.a consisting of monomers M1, M2 and optionally M3, to obtain a first aqueous polymer dispersion, where the monomer composition M.a comprises at most 2% by weight, in particular at most 1.5% by weight and especially at most 1.5% by weight or at most 1.0% by weight, based on the total weight of the monomers of the monomer composition M.a, of monomers M2, and subsequently ii) at least one further aqueous radical emulsion polymerization step of a second monomer composition M.b consisting of monomers M1, M2 and optionally M3, where the second step is performed in the aqueous polymer dispersion of the first step and in the presence of a chain transfer agent T, where the monomer composition M.b comprises 2 to 20% by weight, in particular from 5 to 18% by weight and especially from 8 to 16% by weight, based on the total weight of the monomers of the monomer composition M.b, of at least one monomer M2, where the weight ratio of the total weight of monomers of monomer composition M.a to the total weight of monomers of monomer composition M.b is in the range from 10:90 to 90:10, in particular in the range from 50:50 to 87:13, especially in the range from 60:40 to 85:15.