Cobalt accelerator is a low molecular weight homogeneous liquid from pink to deep purple in color. The accelerator is available in various concentrations: 1%, 1.5%, 6%, etc.

Features of cobalt naphthenate:

– dissolves in styrene in any ratio;
– compatible with all types of unsaturated polyester resins.


Cobalt naphthenate is a cobalt salt of naphthenic acid. A solution of cobalt naphthenate in styrene is used as an accelerator for the polymerization of polyester resins.

For the “cold” curing of resins, two-component initiating systems are intended – an accelerator / accelerator and a hardener / catalyst. An accelerator is selected depending on the catalyst. Cobalt naphthenate is used when the catalyst is methyl ethyl ketone peroxide (MEKP). Thanks to the accelerator, the catalyst decomposes faster. As a result of decomposition, radicals are formed, which initiate curing. Thus, the cobalt accelerator shortens the resin curing time at room temperature without the need for external heat sources.

Application features

Some types of resins are shipped fast. For example, the manufacturer CIECH Sarzyna denotes the pre-accelerated resin Polimal with the letter “P” in its name. Only the catalyst is added to such resins. The accelerator was included in their composition in advance at the production stage.

If the resin is not pre-accelerated, then a premixed cobalt accelerator is introduced during its processing, and then liquid MEKP.

Alternatively, the resin can be divided into two even pieces. Introduce an accelerator into one, and MEKP into the second. Then mix both parts thoroughly.

Each polyester resin manufacturer determines the exact proportions of additives to be added. The manufacturer’s specific recommendations for the specific resin should be followed.

Conditions of use and storage

– Store in a tightly closed container, protected from atmospheric precipitation.

– Keep the accelerator away from heat sources and direct sunlight.

– The recommended storage temperature is below +20 C.

– The personnel working with the accelerator must be provided with overalls, rubber gloves, goggles.

– Work should be carried out in a well ventilated area equipped with ventilation and fire extinguishing equipment.

– It is strictly forbidden to mix the accelerator and MEKP at the same time: the result may be a violent reaction, fire, explosion !!!

– It is strictly forbidden to store the accelerator near the hardener or other chemical products.

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