Anti-corrosion and decoration are two important functions of coatings. Corrosion includes metal corrosion, wood decay, concrete and masonry erosion, weathering, etc. However, the chemical and electrochemical corrosion of metals is still the most destructive corrosion, so the anticorrosion of coatings is mainly aimed at metals.
Anti-corrosion coatings prevent certain bottom corrosion by shielding, corrosion inhibition and cathodic protection. The shielding effect means that the coating prevents water, oxygen and ions from corroding the metal through the coating; the corrosion inhibition effect is that the anti-rust pigment in the coating dissociates corrosion inhibitor ions to delay metal corrosion; the cathodic protection effect is the metal added to the coating Powders, such as zinc dust, allow the base metal to become the cathode of a chemical battery without corrosion.
Coatings with anti-corrosion as the main function are called anti-corrosion coatings. The anti-rust paint is only a primer, while the anti-corrosion paint generally consists of several layers of coatings to form an overall system, including primers, intermediate coats and top coats, but there are also single-layer ones, such as powder coatings. System, such as lead ship paint, offshore oil production platform paint, automotive anti-corrosion paint, bridge paint, railway vehicle paint, heat exchanger paint, shop primer, etc. Commonly used are two-component epoxy paint, epoxy asphalt paint, epoxy phenolic paint, polyurethane paint, asphalt paint, chlorinated rubber paint, chlorosulfonated polyethylene paint, chlorine T rubber paint, perchlorethylene paint , Vinyl hug. Acrylic resin paint (mainly used as floor coverings), phenol paint, etc. Alkyd paint and grease paint are often used as anti-corrosion paint in occasions with low requirements.
