Corrosion Protection from Inhibitors and Inhibitor Combinations Delivered by Synthetic Ion Exchange Compound Pigments in Organic Coatings

  • Chrisanti, S. (Fontana Corrosion Center, Department of Materials Science and Engineering, The Ohio State University) ;
  • Ralston, K.A. (Fontana Corrosion Center, Department of Materials Science and Engineering, The Ohio State University) ;
  • Buchheit, R.G. (Fontana Corrosion Center, Department of Materials Science and Engineering, The Ohio State University)
  • Published : 2008.08.01

Abstract

Inorganic ion exchange compounds (IECs) including hydrotalcites and bentonite clays are a well known classes of layered mixed metal hydroxides or silicates that demonstrate ion exchange properties. These compounds have a range of applications from water purification to catalyst supports. The use of synthetic versions of these compounds as environmentally friendly additives to paints for storage and release of inhibitors is a new and emerging application. In this paper, the general concept of storage and release of inhibiting ions from IEC-based particulate pigments added to organic coatings is presented. The unique aspects of the IEC structure and the ion exchange phenomenon that form the basis of the storage and release characteristic are illustrated in two examples comprising an anion exchanging hydrotalcite compound and a cation exchanging bentonite compound. Examples of the levels of corrosion protection imparted by use of these types of pigments in organic coatings applied to aluminum alloy substrates is shown. How corrosion inhibition translates to corrosion protection during accelerated exposure testing by organic coatings containing these compounds is also presented.

Keywords

Acknowledgement

Supported by : Concurrent Technologies Corporation

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