Bayer Materialscience Puts Environmentally Friendly Waterborne 2K Polyurethane Coatings On The Fast Track
Pittsburgh, PA - The outstanding properties of polyurethane coatings have made them an up-and-coming segment of the coatings market. The coatings industry's challenge now is to significantly reduce the VOC levels in these coatings without sacrificing high property levels. Bayer MaterialScience LLC (BMS), a leader in coatings raw materials, has addressed this challenge by developing technology for the design of waterborne two-component (2K) polyurethane coating formulations with low emissions, yet the same revered curing speeds and high protection levels as their solventborne counterparts.
In addition to their low emissions of organic solvents, waterborne 2K polyurethane coatings are characterized by rapid curing at low temperatures and a good balance of resistance properties, film appearance and mechanical strength. However, a challenge arises from the fact that waterborne coatings in many cases lag behind solventborne systems with respect to drying speed. To combat this issue, BMS is developing new generations of polyol dispersions for 2K polyurethane systems that exhibit improved physical drying and accelerated chemical curing.
Christoph Irle, BMS AG, discussed these innovative formulations in his poster presentation: Waterborne 2K PUR Coatings on the Fast Track. Irle, along with BMS co-authors Aaron Lockhart, Scott Grace and Ed Squiller, presented their overview at the recent 2008 American Coatings Show and Conference in Charlotte, N.C.
The new generation of highly reactive polyol dispersions developed by BMS allows for the design of waterborne 2K polyurethane coating formulations that exhibit significantly faster drying than traditional systems. This innovative solution greatly increases the productivity of low-VOC 2K polyurethane systems, opening the door for potential new markets, including site-applied, industrial and fast running roll-to-roll applications.
"Rapid growth in the 2K polyurethane coatings market is being driven by legislation, but also by end users demanding low solvent emissions and low smell," said Irle. "Bayer's new generation of polyol dispersions will help pave the road to success for 2K waterborne polyurethane technology, and the continuous development of improved polyols and polyisocyanates will influence new market standards in environmentally friendly high-performance coatings."
The presentation highlighted a new proprietary technology that includes an internal activation of the chemical reaction between polyisocyanate and polyol. The resulting reaction is completed significantly faster, while end properties and important application parameters such as viscosity and pot life are not negatively affected.
The authors explained that this new technology has already been successfully implemented to accelerate formulations at low curing temperatures, and to increase productivity of coatings processes under forced drying conditions.
SOURCE: Bayer MaterialScience LLC