Alternatives to butyl-based organotin catalysts in two component polyurethane coatings
Hamburg, 09.03.2017 – Reaxis, co-exhibitor to The NRC Group at the 2017 ECS, offers an alternative to dibutyltin dilaurate catalysts in two component polyurethane coatings: REAXIS® C218. The use of this product is not subject to any severe restrictions and also demonstrates excellent dry times.
Due to increasing regulations regarding the use of butyl-based organotin catalysts, formulators are on the look for alternative options. Substitutes for dibutyltin dilaurate are of particular interest, since this catalyst is widely used in polyurethane formulations. Reaxis can offer an outstanding solution with REAXIS® C218.
Presented below is data comparing the physical properties of catalysts based on bismuth, zinc, octyl and methyl tin. The chart shows dry time data while the table presents the results of tests on pencil hardness after one day and after seven days. The model formulation used is a solvent-borne coating system that consists of a hydroxyl-functional polyacrylate polyol (supplied 70% in butyl acetate), ethyl acetate and an aliphatic isocyanate trimer based on hexamethylene diisocyanate (HDI). An NCO/OH index of 1:1 was used with a catalyst loading of 0.2 w/w% based on resin solids. The films were each drawn at a wet thickness of 100 microns.
These innovative product solutions will be presented at the 2017 ECS by experts from both The NRC Group and Reaxis at their shared exhibition booth, Stand 4-640 in Hall 4.