METHOD FOR TREATING CIRCULATING WATER IN PAINT BOOTHS

摘要

The invention relates to a method for the treatment of circulating water in paint booths, whereby the paint particles are dispersed by adding dispersant s selected from the group consisting of: a) homopolymers and copolymers based on maleic acid, acrylic acid and/or methacrylic acid with a molar mass ranging between 2500 and 500 000; b) non-ionic surface active agents; c) anionic surface active agents, whereby no polyaspartic acid is additionally added to the circulating water in said case and d) inorganic or non-polymeric organic complexing agents and mixtures thereof, their total concentration ranging fr om 0.01 to 2.0 percent by weight in relation to the circulating water. Accordin g to said method for the treatment of circulating water in paint booths, the circulating water has a hardness of at least 2~ measured in accordance with the German water hardness system. By adding dispersants in a concentration ranging between 0.001 and 2.0 percent by weight in relation to the circulati ng water, the paint particles are dispersed in such a way that they have a mean particle size of less than 20 .mu.m determinable by laser diffraction.