The use of Pigment Carbon Black in plastic industry is avoiding ultraviolet aging, because the carbon black have higher suction of light, they can effectively prevent the light oxidation degradation of plastic by sunlight. Carbon black as ultraviolet light stabilizer in plastic, the role is: bring the light energy into heat energy; Protection plastic surface from certain wavelengths of ray; Intercept of atoms and the anti-aging, and then prevents catalytic degradation. UV polyolefin is special harmful, test proved that when certain fineness of carbon black is 2%, it can achieve perfect might prevent ultraviolet radiation shielding.
Carbon black's protection of aging in plastic in the ultraviolet ray depends on the particle size, structure and surface chemical of carbon black.
when Pigment Carbon Black particle size distribution is lesser, for surface area increases, its absorbing light and shading ability increases, so UV protection is enhanced, but when it less than 20 nm, its protection tend to the same level, the reason is when the particle size is too small, reverse scattering reduced, and the continued light will be threat the stability of the polymer.
when Structure is low, namely aggregate size is too small, for aggregate geometry are smaller, it will enhance the protection of polymer, which is the reason of low structure carbon black is very black.
When Specialty Carbon black surface have more oxygen, that is higher volatile, it can eliminate the gene produced from polymer decomposition, so protective effect is enhanced.