The acid and alkali resistance of the pigment refers to the corrosion resistance of the pigment to acid (H I ) and alkali (OH ). Generally, if the acid resistance is not good , it cannot be used for coloring in acidic medium, and if the alkali resistance is not good, it cannot be used in alkaline environment. The determination of the acid and alkali resistance of the pigment is to observe the staining of the solution and the discoloration of the pigment itself after the pigment is contacted (soaked) with the acid solution and the alkali solution respectively . Pigments with good acid resistance include carbon black, chromium white and most polycyclic, azo-condensed, and cyanine organic pigments; pigments with excellent include carbon black, chromium white, metal oxide pigments and most polycyclic pigments. Cyclic, azo-condensed, and cyanine organic pigments.
Chemical resistance refers to that in chemicals, in addition to corrosive substances such as acids and alkalis, there are also corrosion resistance such as salt resistance, strong oxidant resistance, oil resistance, and strong solvent resistance. For anti-corrosion coatings for equipment pipelines containing and transporting these substances, the selected pigments should be able to withstand the erosion of these substances for a long time.
