Carbon black is virtually pure elemental carbon in the form of colloidal particles that are produced by incomplete combustion or thermal decomposition of gaseous or liquid hydrocarbons under controlled conditions. Carbon black is chemically and physically distinct from soot and black carbon. Its physical appearance is that of a black, finely divided pellet or powder. Its use in tires, rubber and plastic products, printing inks and coatings is related to properties of specific surface area, particle size and structure, conductivity and colour.
Adding carbon black to products affects materials in a few ways. When used in tires and other rubber products, it’s primarily a filler, taking the place of more costly binder materials. As a filler in tires, carbon black also helps extend the life of the tire by conducting heat away from the tread and belt area. It also acts as a pigment, making rubber materials black. Pigmentation is carbon black’s primary function in plastics, paints, ink, laser printer toner and some radar absorbent materials. Its high tinting strength and inherent stability make it an especially good pigment, and it’s also used to colour resins and films. When added to polypropylene, carbon black also helps preserve the material from ultraviolet damage since it absorbs UV rays. Carbon black is also a good electro-conductor, so it’s used in certain electronics applications as well.
