Observing carbon black particles under the electron microscope shows that they have a complicated structure, with some spheric particles being fused together.
The size of spheric particles is called "particle size," and the size of the particle chain is called "structure."
Various functional groups such as the hydroxyl or carboxyl group are found in the surface of carbon black, and their amount or composition is called "surface chemistry."
These three - "particle size," "structure," and "surface chemistry" - are the basic properties of carbon black, and together are called the three main characteristics.
The three main properties have a large effect on practical properties such as blackness and dispersibility when they are mixed with inks, paints, or resins.
Particle Size
The diameter of spheric particles is the fundamental property which largely affects blackness and dispersibility when carbon black is mixed with resins or other vehicles.
In general, the smaller the particle size is, the higher the blackness of carbon black becomes.Dispersion, however, becomes difficult due to an increase in coagulation force.
Structure
Like particle size, the size of the structure also affects the blackness and dispersibility of carbon black n330.
Generally, the increase of structure size improves dispersibility but lowers blackness.
Carbon black with a larger structure in particular shows an excellent conductive property.
Surface Chemistry
Various functional groups exist on carbon black’s surface. The affinity of carbon black with inks or paint varnishes changes depending on the type and amount of the functional groups.
Carbon black, with a large amount of hydroxyl group given with oxidation treatment, has a greatly enhanced affinity to print inks or varnishes, showing an excellent dispersibility.
Pigment Carbon black