Study on water-based coating system for exterior steel part

Abstract

Popular architectural painting system for the steel parts consist of one priming coat and two finishing coats and the total dry film thickness is less than 100μm. It is too hard to block factors (oxygen, water, moisture) which accelate the corrosion with such thin layer, by the improvement of primer blocking quality only. Blocking performance of ordinal water base top coat is not high, and it is easy to occur blisters under wet condition. In this study, we measured water and water vapor permeability of various topcoats, and clarified relationship between the data with blistering and with anti-corrosion property. And we found out the effectiveness of dispersing of hydrophobic group component into emulsion particles to nano-size for enhancing hydrophobic bonding force between emulsion particles.