Quantitative Physical Stability Analysis of Paint, Ink and Coating Dispersions
Pigment, inkjet, paint and coating dispersions possess inherent stability issues, typically in regards to sedimentation and packing of the particles in the suspension. Such destabilizations can result in appearance and overall reception concerns for a customer, or can directly correlate to problems associated with the manufacturing, production and storage processes. Issues related to raw material control, ingredient regulations, new formulation development and shelf life stability all result in the need for a quantitative technique to monitor and predict the stability of such dispersions. Here, we will show how an optical device based upon multiple light scattering can be used to quantify physical destabilization phenomena such as sedimentation, clarification and flocculation, all without sample preparation or dilution. While visual analysis can take days, weeks or even months, full destabilization profiles on opaque samples can be generated in a high- resolution fashion. This technique allows for facile modification of the mixtures to fit a stability profile as ingredients change or as new materials are developed and can help assist in packing and redispersibility analysis as well as shelf life predictions.