Primary (Active) Driers

Primary, or active, driers are typically clear to brownish liquids, formulated as metal carboxylates, most commonly containing cobalt, manganese, or iron. Their functionality is to initiate and accelerate the oxidative polymerization of alkyd and other air-drying resins by acting as oxygen carriers, promoting rapid surface drying. Key features include strong catalytic activity, fast film formation, and good through-dry characteristics when combined with secondary driers. They are highly suitable for solvent-borne alkyd paints, varnishes, and enamels, where achieving a quick, tack-free surface and efficient cure at ambient temperatures is crucial for production efficiency and film integrity. 

A significant trend is the strong push towards non-cobalt primary driers, primarily manganese and iron-based alternatives, driven by regulatory restrictions and environmental concerns regarding cobalt. Sub-types are characterized by the specific metal ion, with cobalt historically being the most prevalent, and manganese/iron gaining increasing prominence.