Use of highly-branched polymers for producing polymer dispersions with improved freeze/thaw stability
The present invention relates to a method of producing polymer dispersions having improved freeze-thaw stability, by adding a highly branched polymer to said dispersions, and also to the use of highly branched polymers for this purpose.
1. A method of producing an aqueous polymer dispersion having improved freeze/thaw stability, comprising
free-radical emulsion polymerizing at least one ethylenically unsaturated monomer (M); and
adding at least one highly branched polymer, wherein the at least one highly branched polymer is at least one hyperbranched polymer having a degree of branching DB of 10% to 95%, and wherein at least one highly branched polymer is a hyperbranched polycarbonate, poly(ethercarbonate), poly(estercarbonate) or poly(etherestercarbonate) or a mixture of hyperbranched polymers which comprises at least one hyperbranched polycarbonate, poly(ethercarbonate), poly(estercarbonate) or poly(etherestercarbonate).
2. The method according to claim 1 , wherein the adding takes place subsequent to the emulsion polymerization.
3. An aqueous polymer dispersion obtained by a method according to claim 1 .
4. A binder composition, comprising
an aqueous polymer dispersion obtained by a method according to claim 1 ;
at least one highly branched polymer; and
optionally, at least one further film-forming polymer.
5. A coating material in the form of an aqueous composition, comprising
a binder composition according to claim 4 ;
optionally, at least one inorganic filler and/or at least one inorganic pigment;
optionally, at least one further auxiliary; and
water.
6. The coating material according to claim 5 in the form of a paint.
7. The paint according to claim 6 in the form of a transparent varnish.
8. The paint according to claim 6 in the form of an emulsion paint.