Novel, Effective, Non-toxic Zinc Free Anticorrosive Pigments for Industrial Maintenance Paints

摘要

A recently developed, innovative family of anticorrosive pigments for paints and coatings is based on Oxy-Amino Phosphate of Magnesia (OAPM) technology. On exposure to corrosive environments, they form a stable layer of magnesia on the metal surface which protects it from corrosion attack. These pigments, which are non-toxic, do not contain chromium, zinc or any other hazardous material, give excellent performance in two-component epoxy, alkyd, wash primer and water-based industrial systems. They meet the requirements for long term anticorrosive protection of both steel and aluminum in industrial maintenance applications, and are especially suitable for DIY (Do It Yourself) paints where the environmental hazard warning label of zinc compounds can be avoided. The high effectiveness of OAPM pigments enables lower loading in the paint formula than, that needed with zinc chromate, zinc phosphate and modified zinc phosphates to achieve the desired protection qualities and performance. This leads to cost effectiveness in addition to the health and environmental advantages. This article describes the structure of the protective film formed on the metal surface, and some of its electrochemical and analytical characteristics. The protective layer was investigated by static and dynamic potentials, impedance measurements, Auger and EDAX analyses. In addition, guidelines for formulating organic coatings with OAPM pigments are presented along with test results.