| abstract |
A process for preparing an aqueous coating composition of the present invention comprises the steps of providing an aqueous polymer dispersion having a pH of less than 7, and in said dispersion, from 1 to 30 ppm by weight, based on the total weight of the dispersion, of 5-chloro-2- adding methyl-3(2H)-isothiazolone (CIT) and 10 to 1000 ppm by weight of 2,2-dibromo-3-nitrilopropionamide (DBNPA). One or more adjuvants are also added to the dispersion to form the coating composition. When using the coating composition, DBNPA is degraded by raising the pH of the coating composition, and CIT is degraded by raising the pH of the coating composition or adding a CIT-degrading compound to the coating composition. |