Corrosion Prevention in Paints and Coatings

By Cynthia Challener

When most people think about paints and coatings, they tend to focus on how the coating will affect the appearance of the substrate in question. While improving appearance is indeed a key attribute of paints and coatings, many also provide additional functionality. Paints and coatings that assist in the prevention of corrosion play a significant role in protecting valuable property for the military, government, industry, and the individual as well. Investment in innovation has enabled suppliers of corrosion protection tech­nologies to respond to the changing environmental regulations, increasing offshore competition, and rising raw material and energy prices that they face today.

Corrosion carries a very high price tag for the United States. In 2002, the total annual estimated direct cost of corrosion in the U.S. was estimated to be $276 billion, or about 3.1 % of the nation’s gross domestic product
(GDP), according to a study initiated by NACE International-The Corrosion Society. A 2001 U.S. government-sponsored study estimated the costs of corrosion for military systems and infrastructure alone to be about $20 billion annually. The Department of Defense has since established a central corrosion control activity and strategy that includes a strong push to bring corrosion control to the forefront and an increased emphasis on train­ing and specification.

Paints and coatings serve as one of the key methods for protecting metal surfaces from corrosion. “Corrosion protection is one issue that penetrates across all segments of the coatings market,” notes Michael D. Brown, vice president of The ChemQuest Group, Inc., a management consulting firm lo­cated in Cincinnati, OH. Formulators use three basic strategies to provide corrosion protection: barrier technology to prevent oxygen and water from getting to the surface; passivation of the metal surface using corrosion in­hibiting additives; and galvanic protection using a sacrificial metal additive.