Water paint is a coating that uses water as a diluent and does not contain organic solvents. It has the characteristics of energy conservation, environmental protection, non flammable and non explosive, ultra-low emissions, low-carbon health, and can be widely used in various materials such as wood, metal, industrial coatings, plastics, glass, and building surfaces. From a long-term perspective, water-based coatings are the trend for future development.
Analysis of the Application Fields of Waterborne Coatings in China
Analysis suggests that the development of water-based industrial coatings by coating companies is undoubtedly the greatest benefit to the environment, and can also lower the prices of foreign water-based industrial coating brands in the current market, benefiting domestic consumers. However, water-based industrial coatings are an environmentally friendly high-end product with high technological content, and there are also significant differences in production and painting processes. Coating companies should gradually improve in this regard and not rush to achieve success, otherwise immature water-based coating products will flow into the market, which will affect the development and operation of the entire water-based industrial coating industry. The following is an analysis of the application fields of water-based coatings in China.
Waterborne industrial coatings are mainly used in fields such as automobiles, railway vehicles, bridges and pipelines, steel structures, containers, etc. Currently, there is a significant gap in the level of water-based industrial coatings in China compared to industrialized countries.
Automotive Coatings:
With the rapid development of the automotive industry, the usage of automotive coatings is also constantly increasing. Since Shanghai General Motors launched its first water-based automotive coating production line in Shanghai in 2008, all new domestic automotive coating production lines have been designed with water-based coatings, and water-based coatings have become the mainstream of automotive coatings. Automotive coatings mainly include primer, intermediate coat, and topcoat, among which the topcoat is further divided into natural color paint and metallic flash paint. The water-based process of automotive coatings is gradually carried out from bottom to surface.
As early as the 1960s, developed countries such as Europe and the United States had already taken the lead in using water-based electrophoretic primers. Currently, more than 90% of primers use water-based coatings, 88% of automotive intermediate coatings also use water-based technology, and the application of water-based metal flash primer has exceeded 65%.
Railway Vehicle Coatings:
Most car body coatings use traditional solvent based coatings, which contain a large amount of organic solvents, which bring inconvenience and safety hazards to storage, transportation, and construction. The harmful gases released during the production and use of solvent based coatings can have an undeniable negative impact on the health of production employees and the atmospheric environment. In developed countries, powder coatings, 100% solid content liquid coatings, and water-based coatings have become the mainstream coating systems in the railway vehicle manufacturing industry, with the application of water-based coatings becoming increasingly widespread.
Heavy duty anti-corrosion coating:
Corrosion and rust of metal products can be seen everywhere in daily life, causing waste of resources and energy, economic losses, and sometimes even endangering personal safety. According to some corrosion loss data released by countries such as the United States, Japan, and Canada, direct economic losses caused by corrosion account for 1% to 4% of the total national economic output value. Steel that corrodes and rusts accounts for about 20% of the annual production, and about 30% of equipment is scrapped due to corrosion. The economic losses caused by metal corrosion in China each year account for about 4% of the gross domestic product, and such astonishing losses stimulate the development of anti-corrosion coatings.
Developing environmentally friendly industrial heavy-duty anti-corrosion coatings is a high-tech project actively explored by coating experts from many developed countries around the world, and it is also an emerging field in China. In some typical heavy-duty anti-corrosion coating markets, such as infrastructure, oil and gas, electricity, bucket tanks, marine and chemical industries, the use of water-based coatings is constantly increasing. There are water-based alkyd systems, water-based epoxy systems (epoxy mica iron intermediate coating and epoxy zinc rich primer), water-based inorganic zinc rich systems, water-based epoxy ester systems, etc. used in the field of heavy corrosion protection.
Waterborne container coating:
At present, the annual production of containers in the world exceeds 3.5 million standard containers, requiring approximately 400000 tons of paint annually, with a value of approximately 6 billion yuan. At present, most of the container coatings used worldwide are solvent based. During the production and painting process of containers, a large amount of harmful gases are generated, which not only endangers the health of painting workers but also causes environmental pollution.
With the increasingly strict environmental regulations, the International Container Standardization Committee has put forward higher requirements for the environmental protection and hygiene of container coatings: for example, the coatings must not contain heavy metals such as Cd, Pb, Cr, Hg, etc; Using non-toxic pigments such as phosphates; High solid content, low VOC, etc. Acrylic topcoat replacing chlorinated rubber topcoat and box bottom specialized paint are also gradually being promoted. Waterborne container coatings have started pilot applications in China.
