ADVANCES IN FLEXIBLE WATERBORNE EPOXY DISPERSIONS FOR ZINC-FREE ANTICORROSION PRIMERS

摘要

A new waterborne type 1 epoxy emulsion with high flexibility and improved shear stability is presented. In contrast to other flexible epoxy emulsions, the new emulsion allows direct grinding of pigments and extenders on a pearl-mill under processing conditions typical for standard waterborne epoxy emulsions. The unique combination of flexibility and pigmentability opens up new possibilities for the formulation of advanced flexible two-pack epoxy anticorrosion primers with improved performance. Anticorrosive pigment free waterborne primers can be formulated showing anticorrosion performance comparable to paint formulations containing zinc based and zinc-free anticorrosive pigments. The use of the new epoxy emulsion in waterborne two-pack anticorrosion primers is investigated. The results of salt spray tests and condensation water climate resistance tests of zinc-free waterborne two-pack epoxy systems are compared with the performance of zinc-containing waterborne and solvent borne state-of-the-art two-pack epoxy systems.