Carbon black will have a blue phase and a red phase distinction. Carbon black is undeniably black, so why are there slight differences in hue? What properties of carbon black are these phenomena related to?
In general, the blackness of Pigment Carbon Black has the most direct relationship with its own original particle size.
When the original particle size of carbon black is smaller, its own blackness is higher, and the red phase will be more Obviously; the carbon black product with larger particle size will show a better blue phase relatively speaking, but its own blackness is not as good as the former.
It is not that the blackness of the color paste prepared by blue phase pigment carbon black is lower than that of red phase carbon black, which largely depends on the grinding efficiency of the grinding equipment. The original particle size of red phase carbon black is small, and the requirements for grinding equipment are relatively higher in actual use.
All sunlight is absorbed, and the visual representation of no reflected light is blackness. However, carbon black particles are very small, and the fine particles can reflect very little light, and the wavelength of light has a certain relationship with the particle size.
The particle distribution of pigment carbon black particles in the coating, etc. is different, and the reflected part of the wavelength of light is different. Correspondingly, a black paint will show a blue, red or brown shade.
There is a situation in which blue pigments (such as phthalocyanine blue) are added to the black paste. This is to show the blue phase, and the naked eye feels that the blackness is good. Of course, the correct way to improve the blackness is to disperse the carbon black better and reflect the optimal blackness.