Due to the different ways of water-based resins, water-based coating systems are usually divided into three categories: ① water-soluble; ② micellar dispersion; ③ emulsion. Most resins can form these three water-dispersed forms, such as alkyd and acrylic, which have these three forms of products. However, for the same kind of resin, due to the great difference in the relative molecular weight of the polymer and the size of the dispersed particles in different forms, the performance of the water-based coating is also very different. The performance comparison of the three types of water-based coatings is shown in Table 1-3-1.
The largest output of water-based coatings is architectural latex coatings, and some thermoplastic latexes of the same type are also used as industrial maintenance coatings for metal surface coating; thermosetting electrophoretic coatings are better used on metal surfaces, and industrial large-scale primers are almost all The first is to use electrophoretic coatings, which are the mainstream of water-based coatings for metals. Other types of water-based paints account for a small proportion, but high-quality automotive decorative water-based topcoats have been successfully developed abroad and are in the trial stage. However, water-based coatings that dry at room temperature cannot meet the requirements of heavy anti-corrosion, but research on heavy-duty anti-corrosion water-based epoxy and water-based polyurethane room-temperature drying coatings has great potential and greater practical significance, because they are more harmful to the surface of materials than solvent-based coatings. It has better adaptability to the construction environment.
