Anti-skinning agents for alkyds: MEKO-free options

 
In solvent-based alkyd paints, an anti-skinning agent is normally added to prevent unwanted drying in the can. Traditionally MEKO (methyl ethyl ketoxime) is used for this, but its use is facing potential regulatory obstacles. Therefore, MEKO-free alternatives have received much attention in the last few years. Although many anti-skinning agents are nowadays available, these are based on a limited number of active ingredients. These active ingredients were classified and their effectiveness evaluated as anti-skinning agent. In order to efficiently measure skinning behavior, a method was developed to screen large sample amounts. Skinning behavior and drying speed were evaluated for MEKO-free formulations, amongst other properties. Also, long-term stability of anti-skinning agents was studied. Differences in skinning tendency were observed between different primary driers.