Ion exchange compounds for corrosion inhibiting pigments in organic coatings

This paper summarizes emerging work on the use of synthetic inorganic ion exchange compounds as pigments in organic coatings for storage and release of non-chromate corrosion inhibitors. The basic principles of ion exchange and new synthetic ion exchange compounds being explored are described. The two main research thrusts that currently comprise this research area are presented. The first is based on the use of cation exchanging clays such as bentonite, which have been explored for the delivery of the Ce³ cation. The second is based on the use of anion exchanging hydrotalcites, which have been explored for delivery of a range of anionic inhibitors with a focus on delivery of vanadate oxoanions. How the use of these compounds leads to the ability to sense water uptake by coatings and exhaustion of the inhibitor reservoir is also presented.