Currently, Automobile coating is one of the fastest developing coating varieties, and its application in the field of coating is second only to architectural coating. According to the China Automobile Industry Association, in 2020, China sold 25.311 million cars, with the sales volume of commercial vehicles reaching 5.133 million, up 18.7% year on year; Sales of new energy vehicles reached 1.367 million units, up 10.9 percent year on year. Overall, based on policy support, industry efforts and market demand recovery in 2020, the automotive industry performed better than expected. In terms of trends, car sales are expected to exceed 26 million in 2021, an increase of 4% over the same period last year.
Performance requirements for Automotive Coatings are constantly improving
Automobile coating is the type of coating with the highest performance requirements. The traditional automotive coating is mainly solvent based, and the VOC emission is above 120 g/ m2. Among them, because of the low solid content of metal flash paint, the VOC emission accounts for 66% of the total coating, up to 230 g/ m2. This not only wastes resources, but also pollutes the environment, at the same time, there are fire hazards. The mandatory national standard GB 24409-2020 "Limits of Hazardous Substances in Vehicle Coatings" was officially released on March 4, 2020 and implemented on December 1, 2020, replacing GB 24409-2009 "Limits of Hazardous Substances in Vehicle Coatings". This standard will help to further promote the promotion and use of green and environment-friendly coating products, realize the VOC emission reduction of coating and coating industry, promote the progress of coating technology and product replacement. Waterborne coating solution is one of the important emission reduction measures in coating industr. Low VOC of waterborne coatings not only for the environment, it can also reduce the exposure of constructors to toxic and harmful volatile organic compounds. In 2019, water-based coatings for passenger cars in China have reached 84%, up 19% from 65% in 2015;The water-based coating for trucks reached 48%. Water-based coating solution is one of the important emission reduction measures in the coating industry. The low VOC of water-based coating is beneficial to the environment and can also reduce the exposure of the construction workers to toxic and harmful volatile organic compounds.
Additives for Automotive Aqueous Coatings
Water-based coatings use water as diluent and without organic solvent. It does not contain benzene, toluene, xylene, formaldehyde, free TDI toxic heavy metal, non-toxic without stimulating smell, harmless to human body, and does not pollute the environment.The advantages of waterborne coatings are:
★ waterborne coatings use water as dispersing medium, only a small amount of low toxic alcohol ether organic solvent is used, which is safe and environmental protection, saves resources, eliminates the risk of fire in construction, and it’s beneficial to reduce air pollution.
★ waterborne coatings have good adaptability to material surface, can also be constructed in wet environment, coating adhesion is strong.
★ waterborne paint containers and tools can be cleaned with water. The unused coatings can be stored in a cool place, which not only saves paint resources but also reduces the consumption of clean solvents.
★ Waterborne coating electrophoresis film uniform, good flattening, small gaps and corners can be coated with a certain thickness of the film, easy construction, good protection performance.
A numberof OMNISTAB additives can be used in waterborne coatings to reduce its UV damage. Such as OMNISTAB UV1130, OMNISTAB UV400, OMNISTAB UV400WB, OMNISTAB UV384-2, OMNISTAB UV571, OMNISTAB UV3039; OMNISTAB LS292, OMNISTAB LS123, OMNISTAB LS123DW etc., can play a good protective role in waterborne coatings. Such additives are low alkaline, easy to emulsify, can be well dispersed in waterborne coatings, thus it can provide comprehensive protection for waterborne coatings, and reducing the chemical reaction of UV radiation to the coating surface. It can avoid the occurrence of light color loss, color change, paint peeling and other phenomena.
In addition, for different product applications, we will recommend 2-3 additive products to be used together to achieve better protection effect. For example, UV 400 and LS 292/ LS 123 can significantly improve the performance of the product, this synergistic effect can significantly improve the varnish luster reduction, cracks and bubbles, paint delamination discoloration and other problems. Specific product recommendation welcome to contact our sales staff.
Types of Automotive coatings
1. Primer coating
The main function of automobile primer is corrosion resistance. It is the easiest part to realize water-based. It is also the fastest part in waterborne process. At present, the waterborne coatings used in automotive primers are electrophoretic primers. In addition, some cars use waterborne acrylic and epoxy ester dip coating paint.
2. Floating coating
The Floating coating is different from the primer. First, it has excellent impact resistance and filling performance, which can not only deal with the impact of the crushed stone encountered on the its surface, but also fill the electrophoretic surface. It has a certain isolation ability to the ambient temperature of severe winter and hot summer outside the car body, and can better protect the electrophoretic paint.The main components of waterborne coating include: hydroxyl polyester or polyurethane hydrate as base material, closed isocyanate as crosslinking agent, which can maintain good mechanical properties of medium coating, such as stone strike resistance .
3. Finishing coating
Automotive Finishing coatings include monochrome paint, metallic paint.The role of monochrome paint to withstand climate change, metallic paint to bring more visual coloring, decorative effect. All kinds of advanced techniques in waterborne topcoat coating technology continue to be promoted in China. The popularization of these coating technologies has greatly reduced the VOC emissions of automobile coating, and improved the appearance quality of automobiles. It is predicted that by 2025, most of the world's car manufacturers will be using water-based coatings in their finishes.
4. Repair coatings
The spread of waterborne automotive repair coatings is accelerating.In the air pollution prevention and control programs in the Beijing-Tianjin-Hebei region and the Yangtze River Delta region in recent years, clear requirements promote the coating in the automobile industry to use low VOC content is clearly stated. Since January 1, 2019, All automotive repair coatings should be coatings with VOC content no higher than 540g/L, and the VOC content of Primer&Finishing coating is not higher than 420 g/L.Thus more and more automobile 4S shops began to use water-based repair coatings in these years.
In the next few years, new water-based coating technology and water-based coating product formulation technology will be further developed and become an important development direction of automotive coatings.
DELTACHEM will also keep up with the development trend of the paint industry, to provide customers with more high-quality additive products. On the one hand we will give full play to the original OMNISTAB additives, on the other hand, we will continue to explore and develop more new additives to better serve customers. Our company has been providing customers with a variety of professional solutions in the application of waterborne automotive coatings. While improving the anti-aging and anti-yellowing performance of coating products, we also provide stable product supply and quality. If you have related needs, please feel free to contact us at any time.
Deltachem(Qingdao) Co.,Ltd. looking forward to your inquiry!
