Understanding the Function of Additives

摘要

Why do we call them additives? They are added to a formulation and they add additional properties: what else could we call them? "How do they work" and "How do we design them"? These are more difficult questions. Perhaps this is being overly simplistic, but a coating, at its heart, is a carrier or solvent and a film forming resin or binder. Actually egg tempera paint, which was used in pre-1400 medieval frescoes, was composed of egg yolk, pigment and water. Some artists today still use egg tempera. One could also say that chili is meat, beans and ketchup. While partially true, there are countless chili recipes with a multitude of spices, different meats, and many more sometimes secret ingredients (ask anyone from Texas!). By analogy, additives are the flavors and spices of a coating. Modern coatings are complex formulas with thickeners, emulsifiers, dispersants, pigments, defoamers, leveling agents, photo-stabilizers, curing catalysts and other additives. These additives enhance the inherent properties of the resin.