(1) Barrier primer
Made of inert pigments and various film-forming substances that are stable in the environment in which the coating is used. It only plays the role of mechanical isolation and protection, and has almost no chemical effect on the base metal, so it is suitable for various metals. Commonly used various iron red primers and asphalt primers (including coal tar pitch primers) belong to this type.
(2) Primer with active pigments
Primers containing red lead, basic lead carbonate, basic lead sulfate, zinc white, etc. fall into this category.
(3) Passivation primer
It is the most popular anti-touch primer containing passivating pigments, and chromic acid pigments are commonly used. Red lead containing lead peroxide, which has a passivating effect on ferrous metals, also falls into this category. As a passivating pigment, zinc chrome yellow is the most widely used, and it has good anti-contact properties for ferrous or non-ferrous metals.
(4) Shielding primer
An effective pigment for making barrier primers is zinc powder. Zinc-rich primer has excellent conductivity, water resistance and corrosion resistance, and can play a long-term protective role under harsh conditions. It can be recommended as an anti-corrosion coating for various automobile floors, mufflers, exhaust pipes and agricultural machinery. layer.
(5) Phosphating primer
It is composed of polyvinyl butyral ethanol solution, tetrabasic zinc yellow and phosphoric acid solution. Using a phosphating primer as a primer can significantly improve the quality of the coating.
