Additives That Transform Coatings
Dispersants, defoamers, rheology modifiers and their roles in film build and finish.
Formulation Roles
- Dispersants: Stabilize pigments/fillers, enhance color strength, reduce grind viscosity.
- Defoamers: Control micro/macro-foam to prevent craters and pinholes.
- Rheology Modifiers: Balance sag/level; control brush feel and anti-settling.
- Wetting Agents: Improve substrate wetting and reduce defects.
- Slip/Mar Additives: Boost block resistance and scratch resistance.
Performance Levers
- Optimize PVC and grind profile for opacity and flow.
- Use additive packages to prevent incompatibilities.
- Validate shear profiles (KU/Brookfield/ICI) per application method.
Common Pitfalls
- Over-dosed defoamers causing craters; under-dosed leaving air.
- Viscosity drift from mismatched rheology technology.
- Intercoat adhesion issues from silicone-rich packages.
Lab Checklist
- Grind to target fineness; verify rub-out.
- Screen additive levels at low/med/high.
- Evaluate sag/level, gloss, hardness, and water/chemical resistance.