High-throughput coating research

High-throughput research for developing new coatings or testing and modelling corrosion properties has many advantages. High-throughput technologies allow for rapid, intelligent, parallel experimentation, increasing the productivity of R&D by orders of magnitude over traditional approaches. High-throughput technologies are not limited to merely performing large numbers of random automated experiments until a new material with the desired properties is identified, but involve a more intelligent experimental design set-up. It enables to explore a wider formulation design space more rapidly. In this way, the role of the formulator is less labour intensive and is directed more towards tasks such as experimental design, data analysis and interpretation.

The approach, in which automated systems are used in combination with smart experimental designs, allows accelerated discovery and industrialization. The case of the development of a new UV-curable paint system for metal described below, shows the benefits of high-throughput research. For this development OCAS joined forces with Flamac.

Case – Development of new UV-curable paints for metal using high-throughput

Based on a unique concept, a novel high-throughput workflow integrating liquids and solids mixing, bar coating,  thermal and UV curing, and coating testing has been used to develop new UV-curable coatings on metal. The automated workflow was fully integrated into the data management environment including innovative approaches for the generation of complex, multi-parametric coating recipes. By using the high-speed substrate transfer system, hundreds of coating experiments have been performed under conditions as close as possible to the industrial environment allowing fast transfer of research candidates into pilot and production scale.

The objective was to develop a pigmented UV-curable coating having an excellent adhesion on steel, good flexibility, corrosion- and chemical resistance, hardness and abrasion resistance.
Because of the complexity to formulate such a coating, high-throughput technology was used to screen formulations: different monomers and oligomers have been tested. Several additives, such as corrosion inhibitors, fillers, abrasion resistant and hardness enhanced promoters, have been introduced into the formulations for further optimization.

The effect of each component on the final coating properties can be complex and characterized by synergies and antagonisms depending on the relative concentration ranges of the product components. A design of experiments (DoE) was set up to gain more insight on the impact of each component, as well as the amount of each component, on the final coating properties.

This design of experiments resulted in 250 formulations for screening and optimization. Using the formulation and coating platforms of Flamac, all formulations were mixed and applied to metal panels. These samples were then tested on adhesion, resistance to cracking, salt spray corrosion resistance, resistance to chemicals, hardness and abrasion resistance.

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From the matrix of the 250 formulations some clear conclusions could be drawn.
Adhesion, flexibility and methanol resistance were good for almost all formulations. Corrosion resistance, hardness and abrasion resistance were more difficult to obtain within the same coating but several formulations showed excellent results.

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This study clearly illustrates that high-throughput technologies have contributed to obtain more results, as well as a better understanding of complex systems, in reduced time.

All targeted performances in adhesion, flexibility, corrosion and chemical resistance, hardness and abrasion resistance could be achieved in one UV-curable coating. Various combinations allow making good decisions taking into account cost and performance.

 

“High-throughput technologies allow to obtain more results, as well as a better understanding of complex systems, in reduced time.”

Philippe Legros, Senior Project Leader, OCAS