Anti Corrosive Pigments

Anti corrosive pigments? What are they? Here we try to give a simple explanation.

Over the years, many products have been used (to a greater or lesser degree of success) in the prevention of corrosion, often together with red oxide to produce a red oxide metal primer.

The purpose of primer paints is to act as preparation, forming part of the protective coating for the underlying metal and inhibiting rust formation.

In the past, toxic pigments such as red lead, and carcinogenic pigments such as chromates, have been used. However, due to health concerns they were replaced largely by zinc phosphate. In turn, this old technology was found to be very bad for the environment leading to its replacement by zinc-free systems, replacing the harmful heavy metal zinc with the friendly metal calcium. Since calcium phosphates are widely found in our bodies there are no harmful effects on either human health or the environment from this technology and so modern formulations tend to be zinc-free.

Early versions of zinc-free anti-corrosives first appeared in the late 1980’s when BP became concerned about the leaching of heavy metals and things like zinc-based paints into the sea from their oil rigs. This earlier technology, based on calcium ion exchanged silica, has gradually been superseded by a variety of calcium-phosphate based products such as Nanoguard ACP DCP and Nanoguard ACP2 (used to replace carcinogenic chromates).

Formulation of metal protection products, including direct-to-metal products such as the traditional hammer-finish paints and epoxy coatings, now widely use calcium-phosphate to protect metalwork. With a pedigree developed for the harsh environment of the North Sea oil fields these zinc-free phosphates continue to provide longevity to steel structures around the world without damaging the environment or our health.

Here at Industrial Protective Paints Ltd, all of our products that require anticorrosive properties, for example Regal Anticorrosive Primers and Regal Skip and Container Paint, are manufactured using calcium-phosphate technology.