Using Temperature to Simulate Thixotropy in 100% Solids Coatings

Thixotropy is a very valuable property widely exploited in modern coating formulations to control the flow out in the film. This is usually achieved with rheology modifiers that create this “shear-thinning” behavior.

In conventional solventborne and waterborne coatings, this is virtually the only way to achieve this behavior as temperature simultaneously affects both viscosity and solvent evaporation (including water). In 100% solids coatings however, temperature can be used to simultaneously modify viscosity, reduce the need for monomer thinners, and control the flow out in the film.

In this presentation we will:

• define thixotropic behavior and why it is important in coating applications to achieve the desired surface finish.
• introduce the “temperature hierarchy” in a coating operation.
• compare and contrast key similarities and differences between conventional and energy cure coatings.
• identify the unique properties and behaviors of 100% solid UV/EB coatings that allow temperature to generate “thixotropic-like behavior” in film formation.
• contrast the leveling times available in conventional and energy cure coatings and the influence of the shortened cure cycle.

In addition, we will cite examples where this is being done in current applications.