Polymer powders redispersible in aqueous solution
AssigneeBASF SE
InventorsJörg Breitenbach, Karl Kolter, Angelika Schmitt
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Abstract
Polymer powders redispersible in aqueous solution, their use in cosmetic, pharmaceutical or crop protection formulations and a process for preparing polymer powders redispersible in aqueous solution comprising copolymers carrying free acid or base groups and, if appropriate, auxiliaries, which comprises adjusting the pH of the dispersion prior to drying by the addition of at least one buffer system to a pH of from 2.0 to 6.5 in the case of copolymers carrying free acid groups or a pH of from pH 7.5 to 12 in the case of copolymers carrying free base groups.
Claims6
A process for preparing polymer powders redispersible in aqueous solution which comprises
- preparing a first dispersion of copolymers carrying free acid or base groups,
- adjusting the pH of said first dispersion by the addition of at least one buffer system to a pH of from 2.0 to 6.5, in the case of copolymers carrying acid groups, or to a pH of 7.5 to 12, in the case of copolymers carrying base groups,
- whereby some of the free acid or base groups are converted to salts thereof forming a second dispersion,
- and drying said second dispersion to obtain said polymer powders redispersible in aqueous solution,
- optionally, with the addition of auxiliaries prior to or after drying said second dispersion.
Dependencies are inferred from the claim text.