Cobalt is the most important metal drier for curing coatings based on drying oils and alkyd resins. It is
required to shorten the surface drying of coatings, varnishes, stains and inks and, in combination with a
secondary drier such as zirconium, barium or zinc, will result in uniform through drying of the paint film.
Metal content 4.90 – 5.10 % Cobalt Non-volatile content 40.00 – 55.00 % ASTM D 1644 Viscosity A-5 to A ASTM D 2373 Specific gravity 7.35 – 7.84 lb/gal (25°C) ASTM D 1963
Cobalt based driers catalyze redox reactions which result in the dissociation of hydroperoxides from a change in valence from Co2+ to Co3+. Cobalt based driers result in rapid surface drying. Too much cobalt drier may result in drying defects such as wrinkling, poor through drying and yellowing.
Borchers Cobalt driers are available in a variety of concentrations and organic salts for ease of handling and better solubility in your coatings system. 5% Cobalt Hydro-Cure® II is based on metal salts of neodecanoicacid designed for waterborne coatings only. Cobalt driers are used in all oxidatively cured systems, whether air or force dry. It is used in architectural paints, industrial coatings, stains, varnishes, oil-based inks and artists’ colors.
In conventional alkyd formulations, the cobalt addition is between 0.03 and 0.08 % metal based on the vehicle solids of the coating and will vary upon the composition of the binder. In printing inks, a combination of Cobalt and Manganese driers is recommended. The amount of cobalt is between 0.03 and 0.05 % based on binder solids. Cobalt driers can also be combined with Zirconium and Calcium driers for optimum surface and through dry. The specific drier blend should be experimentally determined.
Protect from the effects of weathering and store at temperatures below 50 °C. Once opened, containers should be resealed immediately after each use.
Please refer to our safety data sheet for information relating to product safety.
- Europe : EINECS
- USA : TSCA
- Canada : DSL