Anti-rust Pigments Are Intended To Prevent Metal Corrosion

The term corrosion stands for the chemical reaction of metallic materials with substances in their environment. The use of coatings that contain rust protection pigments is intended to prevent or delay metal corrosion. As a rule, the formation of rust affects the function of the material. Each component also corrodes differently under the prevailing conditions.

The aim should therefore be to prevent corrosion reactions and their consequences as far as possible. Base, intermediate and top coats with rust protection pigments can be coordinated so that highly effective (heavy) corrosion protection is achieved.

Lead-containing pigments are often used as a base coating on structural steel. B. Red lead (DIN 55916). On the binder base alkyd resin red lead has a passivating effect on

the steel surface. The effect of lamellar lead soaps improves the mechanical strength, water resistance and the adhesion of this protective layer.

Metallic pigments contained in zinc dust primers protect steel components in the cathodic area. The base metal zinc is deliberately connected to the component to be protected in order to shift the corrosive reaction. The resulting oxidation products additionally seal the coating and make further corrosion more difficult. These primers contain a high proportion of zinc dust pigments (DIN EN ISO 3549)

and are mostly processed in conjunction with epoxy resin and alkali silicates. Intermediate coatings in particular provide a barrier effect within the coating system. Pigments, such as iron mica or platelet-shaped iron oxide pigments, have a purely physical effect. The diffusion path for corrosive substances is significantly extended by the formation of lamellar structures in intermediate or top coatings.