What is the difference between water-based paint and solvent-based paint for automotive painting?

The main type of water-based paint is latex paint. Latex paint is mainly composed of four parts: water, emulsion, pigments, fillers and various additives. Solvent-based coatings are composed of four major parts: resin, pigments and fillers, solvents and various additives. It can be seen that the dispersion medium of water-based coatings is water. After the coating is applied, water and a small amount of additives are evaporated from the coating film, which has environmental protection, safety and other properties; while the dispersion medium of solvent-based coatings is organic solvents (generally referred to as VOC). ), the organic solvents evaporated from the coating film are mostly toxic and harmful substances, which not only harm the human body, but also cause pollution to the natural environment.

From the physical and chemical properties of the coating film, some physical properties of water-based coatings The chemical properties are inferior to those of solvent-based coatings, such as chemical resistance, weather resistance, stain resistance, etc. Therefore, water-based paints do not have as long a service life as solvent-based paints. However, there are also some high-end products of water-based coatings: such as water-based silicone acrylic coatings, fluorocarbon coatings, etc., and their service life can also reach about 10-15 years.

In terms of construction environment, water-based coating construction is generally It is required to be constructed above 5℃, and solvent-based coatings can also be constructed at O℃. Therefore, in northern areas, solvent-based coatings can be used for construction near winter.

In terms of requirements for the base layer, the moisture content of the base layer for water-based coating construction It should be less than 10%, and the moisture content of the base layer for solvent-based coating construction should be less than 8%. Water-based coatings have better air permeability, and water vapor inside the base layer can diffuse outward; while solvent-based coatings form a dense film. If the moisture content of the base layer is high, water vapor cannot evaporate from the coating film, and it is easy to foam.