International. Hexigone's latest test results demonstrate that its sustainable corrosion inhibitors, Intelli-ion, achieve C5 levels of corrosion protection in both water-based and solvent-based coatings.
This presents the global coatings industry with the highest level of corrosion protection that is free of heavy metals and chromates.
C1-C5 are classifications used to describe the level of corrosion resistance required for aggressive environments and applications. C5 refers to highly corrosive environments, where the steel structure is exposed to high levels of moisture, salt water spray and other corrosive substances.
Many coating manufacturers formulate coatings to provide protection in these conditions, such as offshore oil and gas platforms, coastal areas, and chemical plants.
The coatings that were tested were formulated at the PRA (Paint Research Association), a UK-based organization that provides technical and scientific support to the global coatings industry.
Reach-compliant inhibitors were added to both water-based (WB) and solvent-based (SB) two-pack epoxy coatings, and only primer and top-coat systems were tested.
The panels used for testing were blasted to Sa2.5 to the C5 specification. Each primer layer had an average dry film thickness (DFT) of 120 μm and the top layer was applied at approx. 60 microns.
After 1440 hours of salt spray testing (SST) according to ASTM B117, both the primer and the complete system for our Epoxy WB and Epoxy SB showed no signs of blistering in the coating system.
To demonstrate the full performance of both systems with AX1, we removed half of the paint system to see the substrate underneath. The WB Epoxy system after 1440 hours shows minimal corrosion in the trace, which evidences the excellent Intelli-ion performance in WB systems.
The SB epoxy system also meets specifications with no blistering, minimal cross-corrosion and no corrosion of the bottom layer present throughout the substrate.
Dr. Catherine Friar, business development manager at Hexigone Inhibitors, commented, "Our award-winning technology provides exceptional infrastructure protection in key sectors and helps address the environmental challenges facing the coatings industry."
"Reaching 1440 hours allows existing manufacturers of C5 paint standards to switch to more sustainable inhibitors or facilitate new C5 REACH compliant product lines through sustainable water-based or solvent-based coatings with low VOCs," continued Dr. Friar.
"These preliminary results indicate that the coating systems would meet the high durability requirements of the corrosivity category ISO 12944:2018 C5. Further testing is underway," Dr. Friar added.
Unlike zinc phosphate, which primarily provides anodic protection through precipitation, Intelli-ion offers protection against both anodic and cathodic corrosion.
The technology is intelligently launched and works by forming a protective nanolayer on the surface of the metal, which provides a physical barrier to corrosion-inducing substances.
Intelli-ion also has unique electrochemical properties that allow it to donate or accept a proton, moderating the pH beneath the film. The final mode of protection occurs once it has donated a proton to the OH- ions resulting from the cathode oxygen reduction reaction, it forms a bonded layer of lone pair on the surface of the metal at the cathode, blocking interfacial electron transfer.
All three electrochemical protection modes are unique on the market and have received recognition by winning the British Coatings Federation's "Sustainable Innovation, Supplier" category in 2022.
