Coating science: the light resistance of pigments and their influencing factors

some pigments under the influence of light, the color has different degrees of changeInorganic pigments will darken in the sun for long periods of timeResearchers believe the phenomenon may be due to chemical reactions or changes in pigment crystalsZinc is darkened in the sun because zinc sulfide is reduced to zinc metal, and dark gray disappears after exposure stops, and zinc oxide may formThe test showed that the zinc oxide content increased after the exposure of zinc palladium whiteAfter chromium yellow exposure, due to the reduction effect, the production of dchromiate lead, resulting in a dark colorpigments change color under the influence of light and are closely related to the catalystdarkened, such as zinc- and white, because it contains a small amount of zinc chloride; Dry-drilled zinc radon changes little or no from light, but the zinc palladium white in tide 5 turns dark in 1 to 2 minutes when it is also lightedall visible spectra have an effect on the color of the pigment, short-wave light such as purple and ultraviolet light has a greater impact and light resistance can be tested in sunlight or in artificial light sources