Current coating technologies utilize anti-corrosion pigments in the primer to protect metals from corrosion. The most effective anti-corrosion pigment is the highly toxic and carcinogenic hexavalent chromium (Cr6+), which refers to chemical compounds containing the element chromium in the +6 oxidation state. The toxicity of Cr6+ became well-known to the general public through the 2000 Oscar- nominated film “Erin Brockovich.” The film presented the real-life story of hexavalent chromium leakage which contaminated both groundwater and drinking water in the small California desert town of Hinkley, leading to the largest legal settlement in the U.S. history. Hexavalent chromium is a carcinogen that can cause severe malfunctions of the human body, contaminate water, soil and air, and harm plants and animals alike. A 2010 study by the Environmental Working Group (EWG) discovered that the Erin Brockovich chemical, Cr6+, was present in the tap water of 31 of the 35 U.S. cities sampled, and 25 of them were at a level above the California-proposed safe maximum. Cr6+ has troubled the U.S. military for over several decades; hexavalent chromium has been named the No. 1 toxic enemy of the U.S. Military. In terms of protecting their mission-critical assets in the military and the aerospace industry, Cr6+ are still in wide usages without and effective alternative been identified. The regulations are tightening.
Zinc and/or zinc oxide are current environmentally compliant industry standard chromium alternatives. However, zinc cannot protect aluminum (a major material for the aerospace industries) or galvanized steel and is less effective in severely corrosive environments. Zinc price is expecting to increase again, and according to figures from the United States Geological Survey (USGS), with the current levels of usage, the known zinc reserve will be depleted around 2020. Over 50% of zinc has been used to protect metals from corrosion either through the galvanization process or as the sacrificial anti-corrosion pigment in coatings. The world has long been diligently searching for an effective Cr6+ alternative pigment for corrosion protection.
Conductive polymers have been regarded as an exciting environmentally friendly alternative to hexavalent chromium pigments since the discovery of the Polyaniline (PAn) anti-corrosion effect in the early1980s. That PAn can be used as a corrosion inhibitor was also stated in the 2000 Nobel Chemistry award publication. Many companies, organizations, and universities have invested significant resources into this research, and hundreds of research papers and patents have been published. Although many researchers have shown some positive results, the development of commercial products has been a long and arduous path in the past 30-plus years.
To meet the demand for an environmentally friendly yet high-performance anti-corrosive, Ancatt Co. has successfully developed Conductive Polymer Nanodispersion (CPND).