Cobalt is an extremely active & most widely used drier in coatings
& capable of being used even as a single Drier.
It is primarily an oxidation catalyst & acts as a " Surface
Drier ". It may have a tendency to cause surface wrinkling,
hence to provide uniform drying. Cobalt is generally used in
combination with other metals, such as Manganese,
Zirconium, Calcium & Combinations of these metals.
As quantity of Cobalt Drier used is very small, it minimizes
discoloration in paints & enamels as compared with other
Driers. Cobalt does not discolor white paints as the deep blue color
of the cobalt counteracts the yellow of the oils &
resins & thereby enhances the whiteness of the paint. The unique
feature of cobalt is that it is least affected by atmospheric
humidity. Cobalt is an effective accelerator for polyester.
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