REUSABLE COLD-CURABLE WATER-BASED COATING COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a cold-curable water-based coating composition that causes no phase separation and coagulation, is reusable because it can increase the efficiency of the filtration and concentration of the coating-dilution water and shows excellent water resistance and corrosion resistance. SOLUTION: The objective reusable cold-curable water-based coating composition comprises (a) an oxidative polymerization type modified epoxy resin water- based dispersion that is prepared by dispersing an oxidative polymerization type modified epoxy resin in an aqueous medium and has a particle size of <=200 nm and an acid value of 25-60, (b) an anticorrosive pigment and/or amphoteric metal oxide and (c) a drier. In this case, the oxidative polymerization type modified epoxy resin in the component (a) is prepared by using an epoxy resin and unsaturated fatty acid component and an acid group-containing acrylic component as raw materials and is prepared by modifying 30-50 wt.% of the above-stated epoxy resin with 25-40 wt.% of unsaturated fatty acid components and 10-45 wt.% of the acid-group containing acrylic component in which at least 50 wt.% of the whole unsaturated fatty acid component is a conjugated double bonds-bearing unsaturated fatty acid.