An investigation of the distribution of minor components in complex polymeric paint formulations using ToF‐SIMS depth profiling

Abstract A series of complex polymeric paint formulations have been investigated by ToF‐SIMS depth profiling. Employing a Bi n + analysis source and a Buckminster Fullerene (C 60 ) etch source in the dual‐beam mode of operation, depth profiles from poly(vinylidene difluoride) (PVdF), poly(urethane) (PU), polyester (PE) and epoxy‐based commercial coatings were obtained to determine the distribution of minor components included in the coating formulation. The addition of small quantities of additives such as flow agents is known to induce significant changes in the surface composition of the paint. Depth profiles were obtained from a PU primer formulation to which a 35 Cl/ 37 Cl labelled flow agent had been added. The depth profiles show that the chlorine tagged component is confined to the surface region of the coating due to segregation of the flow agent to the air/coating surface. Depth profiles obtained from a PVdF topcoat formulation that included a hexamethoxymethyl melamine (HMMM) cross‐linking agent demonstrate that the HMMM intensity is greater at the coating surface than in the bulk. The HMMM depth profile also reveals that the HMMM possesses a depletion zone between the coating bulk and the air/coating surface. Depth profiles obtained from both PE and epoxy primer formulations show that the concentration of inorganic particles included as pigments and anti‐corrosion agents in the coatings is greater in the coating bulk than at the coating surface, demonstrating effective detection of these second phase particles, and that, as expected, they are properly dispersed in the organic phase. The results demonstrate that depth profiling of polymeric coatings, when employing a C 60 etch source, can be used to determine the distribution of minor components within cured coatings. Copyright © 2008 John Wiley & Sons, Ltd.