Binder systems have the most influence on coloristic properties of carbon black in powder coatings, according to a study by Orion Engineered Carbons S.A.

The research, released at the Powder Coating Summit in Columbus, OH, was conducted using carbon black in an epoxy-polyester hybrid and polyester system with HAA and TGIC crosslinkers.

“Based on the study results, we recommend high-color furnace black or high-color gas black for applications requiring high jetness with bluish undertone,” said Trinh Nguyen, the technical market manager at Orion who presented the comprehensive report on coloristic performance, including jetness, undertone, gloss and haze of carbon black in full tone and grey tone powder coatings.

“We recommend low to medium furnace black for applications requiring low to medium jetness, and coarser grades such as regular furnace black or lamp black for tinting applications,” she added.

For typical powder coatings, Nguyen recommended using 1.0%-2.0% loading of carbon black (by weight, on total formulation) to obtain an opaque appearance. Bead and powder forms of the same carbon black grade showed no differences in colorimetric performances of the system.

The Orion study showed that in the hybrid system, the oxidized gas black had inferior coloristic performance to non-oxidized types. In the polyester/HAA system, the non-oxidized gas black provided better pigment stabilization than the oxidized type.

“We’re pleased to offer an extensive portfolio of carbon black grades to meet the requirements of every application,” said Sandra Niewiem, Ph.D., senior vice president, global specialty carbon black and EMEA Region, at Orion. 

Orion offers low-, medium- and high-color furnace- and gas blacks for epoxy hybrid and carboxyl polyester powder coating systems.