Corrosion protection today and tomorrow

By Lars Kirmaier

What are the major goals in today´s anticorrosion pigment market and which technologies have the potential to offer further performance improvements in the future considering environmental factors? By Dr. Lars Kirmaier

Todays´s market

The selection of the right anticorrosive pigments and inhibitors is significantly influenced by the overall formulation, the performance requirements as well as the regulatory background e.g. regarding more and more stringent limits on VOC levels. The application, the substrate, the binder, the pigment volume concentration etc. all influence the protective behaviour to a large extent. Choosing the wrong pigment might result in minor performance properties and -especially in waterborne and high solids systems - often in reduced storage stability. A major goal of the recent decade has therefore been to develop pigments with a more universal usability. These wide spectrum anticorrosives (WSA) are highly modified performance pigments with universal applicability in a variety of binder types and coating technologies. Furthermore, the most recent WSA pigments also exhibit excellent ecological properties e.g. no dead fish/dead tree labelling in Europe.

Taking advantage of synergies achieved by the combination of different components often provide improved performance. A lot of focus has been put by HEUBACH on synergistic and hybrid pigment development, such as augmenting performance with organic anticorrosives. This involves the use of an inorganic anticorrosive pigment in combination with an organic inhibitor also leading to an improved substrate protection at the very initial exposure time. A significant adhesion improvement, especially wet adhesion can be additionally observed.

Future pigment technologies

During the last years nanotechnology has become the catchphrase in the protective coatings market as new technologies develop such as Sol-Gel-Systems. Some methods may incorporate nanostructured materials processing approaches. These include surface treatment methods, nanocomposite thin film coatings, top layer coatings and thermal barrier coatings. The utilisation of nano-sized particles might open up new means for obtaining effective corrosion protection. Nanotechnology has principally the potential to provide unique and enhanced benefits to a wide range of protective coatings applications. Heubach is in fact putting significant effort into the use of this technology for modern anticorrosive pigment development.

Environmental factors

Europe is the largest chemical producing region in the world and the REACH legislation will have a global impact in many ways. Over the next years, some 30,000 chemicals in use today will have to be registered in order to fill information gaps on the hazards of substances and identify appropriate risk management measures to ensure their safe use. This authorisation system will strongly encourage raw material suppliers and paint companies to switch to safer alternatives.

Paint companies are therefore more than ever interested in the sustainability of pigment products, from the standpoint of carbon footprint, efficient use of resources and energy and other environmental issues. The most important trend is the growth of the water-based paint area and the decrease of the solvent-borne one. Waterbased technology will most likely outperform solvent-borne systems in industrial protective coatings in the future, because of the increased regulations to produce low VOC.

As a leading producer of anticorrosive pigments HEUBACH's product portfolio comprises a couple of different pigment technologies in line with the increasing environmental requirements. An example for this point is the new labelling - and zinc-free anticorrosive pigment based on a calcium modified silica gel technology, which has perfectly complemented the existing portfolio of strontium polyphosphate-based pigments for use in thin film systems such as high performance coil coatings.

About

Lars Kirmaier studied Chemistry and completed his dissertation about highly-reactive silicon intermediates in 1998. He joined the R&D department of a leading German paint company and gained hands-on experience in solvent-free and high-solids polyurethane and epoxy resin applications. He is now with Heubach GmbH since January 2004 as laboratory manager for anticorrosive pigments.