Pigment Selection for Architectural Coatings
Competition and environmental regulations require the architectural coatings manufacturers to develop innovative formulations to improve traditional colorant systems. This includes improved hiding, reduced VOC (almost zero), increased durability, and optimum cost of use. Single coat hiding requires specific organic pigments in blends with heavy metal free highly chromatic inorganic pigments. Very low VOC free colorants require unique composition to achieve properties similar to those of regular types. Highly durable colorants require pigments that do not show any significant color change for at least after five years exposure in Florida, which are also resistant to the effect of lime burn with minimum or no efflorescence. Powder and coil coatings are also commonly used for architectural applications. The pigments for these systems require relatively high heat stability and weather fastens as such coatings are guaranteed for long term performance, i.e. minimum color change over 10-20 years. Only a few organic and inorganic pigments meet the requirements necessary for this part of architectural coatings.