Water is a highly polar solvent with high surface tension and insufficient wetting properties. Thus, for proper dispersion and stabilization of carbon black pigments in waterborne coatings, the use of wetting and dispersing additives is essential. The carbon black pigment and polymeric dispersion additive or binder must be compatible. Two ways exist to prepare waterborne coatings:
• A mill base consisting of: polymeric binder as an aqueous dispersion or solution (that is stable against temperature and shear forces), plus wetting agent, defoamer, amine and pigment.
• A mill base without binder consisting of: polymeric additives (instead of the binder), plus defoamer, amine and pigment. The advantage of this system is the high Pigment carbon black concentration, improved coloristic properties and universal applicability.
