Organic salts of cobalt used to speed the curing time of paints, varnishes and printing inks.. Cobalt driers act as an oxidation catalyst, drying the film from the top down. Excessive amounts of drier can cause the films to wrinkle and yellow. Cobalt driers are currently used by the coatings industry. They have been used in artist oil paints since the 19th century. Small amounts (less than 5%) are cooked with the drying oil. They were often used in an oil-based glazing media prepared with stand oil, pure gum turpentine, and dammar. Examples of cobalt driers are cobalt naphthenate, cobalt oleate, cobalt linoleate and cobalt abietate.
Synonyms and Related Terms
cobalt siccative; secativo de cobalto (Esp., Port.); seccativo al cobalto (It.)
Examples include: cobalt octoate (Octa-Soligen cobalt); cobalt naphthenate; cobalt oleate; cobalt lineolate; cobalt abietate
- Excess drier may cause films to wrinkle and yellow.
- Potentially toxic.
- May cause allergic reactions.
Resources and Citations
- Guy Weismantel, Paint Handbook, McGraw-Hill Book Company, New York, 1981