Protective coatings: “Water-borne systems are continuing to grow in importance”
Where is raw materials R&D for protective coatings focused at the moment?
Daniel J. Weinmann,
Mmarket development manager epoxy, Hexion
Daniel J. Weinmann: For R&D groups in the raw materials portion of the protective coatings value chain, product development chemists are focused on several aspects, one being the development of new products that will help coatings formulator reduce solvent emissions (i.e. lower VOCs).
Plus, reviewing the individual components of current commercial products to improve their sustainability and developing product technologies that increase service life (e.g., better corrosion resistance or improved flexibility), or that help to reduce application costs (e.g., reduce the total number of coatings layers) are also key. Another focus is on raw materials enabling coatings that have a more favorable environmental footprint beyond VOC reduction (isocyanate reduction, bio-based etc.).
How prevalent are water-borne systems in the protective coatings sector?
Epoxy global technical and marketing director, Versatics
David Vanaken: In this sector, water-borne systems are continuing to grow in importance. The protective coatings market can be segmented into light-, medium- and heavy-duty applications. Water-borne epoxy systems are well established in the light- to medium- duty protection of concrete and masonry.
As regulations across the United States are reduced to levels of 100 g/L, or 50 g/L maximum VOC, water-borne epoxy systems will continue to grow. For light- to medium-duty industrial maintenance applications, 2K and self-crosslinking acrylic emulsion polymers are being used in applications such as direct-to-metal (DTM).
For heavy-duty applications where corrosion- and chemical- resistance are critical, market-leading companies are commercialising water-borne epoxy systems for metal protection — but these are higher value, smaller volume coatings at this time.
What trends do you think will dominate the market for corrosion protection coatings in the coming years?
Weinmann: In general, a shift toward solutions that allow for cost reduction and coatings that have a lower impact on the environment. Isocyanate-free, lower VOC coatings with acceptable cost and performance similar to current established chemistries remain a hot topic.
Further trends for corrosion-resistant epoxy coatings are the development of hybrid resin systems that provide increased flexibility and improved weathering resistance and reduce the cost of coatings formulation by selecting amine curing agents with lower use levels (PHR), or by selecting epoxy systems with lower mix viscosity. This lower mix viscosity enables higher-filler loadings to reduce costs.
By incorporating lower-yellowing resin systems that use non-isocyanate, crosslinking chemistries, formulators can increase worker safety and potentially reduce the number of coating layers. Another focus is on reducing application costs by formulating wet-on-wet coating systems, faster dry and faster cure systems, or developing coatings with improved surface tolerance.