Among the plethora of additives available today, waxes have a significant impact on many formulations or processes. Even if used in relatively small quantities — typically below 3% solids content of the total composition - waxes impart or improve effects as various as slip and lubrication, abrasion resistance, anti-blocking, matting and water repellency - all critical properties in the coating and ink areas. Hence, waxes are often classified as surface conditioner additives.1,2 This article briefly reviews the major wax families and describes the provided effects in formulations.
Schematic.
The term 'wax' encompasses a large range of naturally occurring and synthetic material constituted from high fatty acids esters (typically C36 - C50) or from polymers (700 < Molecular weight <10,000) that differ from fats in being harder and less greasy. It is, however, important to realize that the chemical composition alone does not determine a wax. Today, there are a large variety of waxes available on the market, often classified according to their origin. Table 1 gives an overview of the most currently used waxes in industrial applications.