A novel, cobalt-free drier featuring manganese neodecanoate and an amine ligand delivers faster drying times for alkyd coatings, reducing toxicity without compromising performance.
Cobalt carboxylates are commonly used as catalysts for the oxidative crosslinking of alkyd resins, which accelerate the drying of paints, inks, and coatings. Despite their effectiveness, alternatives are increasingly sought after, due to concerns surrounding cobalt toxicity. Cobalt 2-ethylhexanoate, specifically, is labeled as Reprotoxic Category 1B by the European Chemicals Agency (ECHA), taking effect from November 2023. Although manganese driers with various ligands are available, few alternatives have been recognized that can match the performance of cobalt driers. To address this issue, the authors of this paper have developed a novel cobalt-free drier that has excellent drying performance and satisfies the requirements of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).
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Design for New Cobalt-Free Drier
For this new design, a new, safer amine ligand with high catalytic activity was selected, along with manganese, a cobalt-free element with much lower toxicity. Manganese neodecanoate was combined with the amine-based ligand, and VOC-free esters used as the solvent in the newly developed DICNATE MV130A.
Source: PCI, Hiroaki Nakano, Manager, DIC Corporation, Ichihara, Chiba, Japan