Carbon black is composed of fine particles consisting mainly of carbon. It gets manufactured in highly controlled processes and contains more than 95% pure carbon. The carbon black particles are fused into chain-like aggregates, which define the structure of individual carbon black grades. Depending on the production process, carbon black types differ in particle size, surface area, porosity and many other characteristics. In most coatings applications, the primary function of the carbon black is as a pigment. Carbon black is excellent coloring agent as black pigment, and therefore is widely used for printing inks, resin coloring, paints, and coatings. Higher color carbon blacks generally have higher surface area. This surface area leads to higher required dispersant loading, dispersion energy, and other processing requirements. A carbon black that is well dispersed will provide deeper color than the same material when poorly dispersed.
Like particle size, the size of the structure also affects the blackness and dispersibility of carbon black. Generally, the increase of structure size improves dispersibility but lowers blackness. Carbon black with a larger structure in particular shows an excellent conductive property. Some applications of carbon black are shown below.
Coloring Agent for Inks and Paints: Carbon black is widely used for printing inks, paints and toners. Carbon black has higher tinting strength compared to iron oxide black or organic pigments.
- Coloring Agents for Plastics: Carbon black is suitable for coloring plastic resins and films because it has high tinting strength and is thermally stable. Carbon black is also excellent for absorbing ultraviolet light, providing better outdoor resistance. Resins with carbon black, such as automobile bumpers, wire coverings and pipe linings will get improved weather resistance and durability.
- Electric Conductive Agent: Carbon black is also used as an excellent antistatic agent. Its particles have the graphite-type crystalline structure, which serve as conductive filler in plastics, elastomer, paints, adhesives, films, and pastes.