| abstract |
The use of bisphenol compound(s) of formula (I) or their salts as drying aids for aqueous polymer dispersions is claimed; in which >= 1 of R<1-8> = a sulphonic acid group (SO3H) and the rest = hydrogen (H); X = alkylene, carbonyl (CO), oxygen (O), sulphur (S) or imino (NR<9>); R<9> = H or alkyl. Also claimed are (a) a method for producing a polymer powder by drying an aqueous polymer dispersion with addition of (I); and (b) the polymer powder per se. |