Effect of Inorganic Salts and Humidity on Adhesion of Coating to Chromo Plating Substrate

Abstract

The effect of inorganic salts and humidity on adhesion was discussed in the coating to chromo-plating substrate. Peeling was occurred in the adhesion test of coated film after washing chromo-plating substrate with water containing inorganic salts. Ca²⁺, Na⁺ as cation and NO₃^-, SO₄^2- as anion were detected in the XPS analysis of the peeling area. It was found that inorganic salts with high water absorbability affected the adhesion. Adhesion was poor when coating was applied under high humidity conditions. It was found that surface energy of the back side of coating film was small from the result of measuring of that.