Automotive coatings, also known as the masterpiece of coating technology, provide corrosion resistance of steel panels that form the car body, protect the car with strong durability against the external environment such as UV rays, acidic rain, salinity, oiliness and chemicals, and beautify the overall appearance of the vehicle. Through a multi-layer structure consisting of electrodeposition, primer, base coat and clear coat, the film performance is increased and high quality is guaranteed.
Since the first application on a vehicle body in 1976, electrodeposition coatings (cation), also referred to as e-coats, have been applied to all vehicle bodies as a primer due to eco-friendly and economic properties.
The latest trends in e-coating technology include an expansion of lead-free electrodeposition in response to environmental regulations, development of low-bake (130-140℃) e-coat in response to the diversification of materials that form the vehicle body and development of high-weatherability electrodeposition and thin-film electrodeposition technologies. Currently, most of the electrodeposition lines in Korea have converted to lead-free type, which is applied to 90% of the global manufacturing system. KCC developed e-coats through technical partnership with Herberts-Vianova in 1984. In compliance with the top 5 heavy metals regulations set by the EU, KCC developed and applied a lead-free e-coat (ED2100) in 2000. Approximately five years later, KCC developed and applied high corrosion-resistant e-coats (ED3000HT/ECO1000) in response to the enhanced corrosion resistance quality of automobiles, and in 2012, by maximizing the interior applicability of e-coats, KCC successfully developed and applied ultra-high throw power e-coat (EC03000), which reduces the amount of consumption and secures stronger corrosion resistance.
Primer is used for leveling of the film and to give durability (chipping resistance) against chipping that may occur while driving and weatherability to extend the durability of the car body.
Surfacer generally consists of denatured polyester or urethane, and is coated on the back with a thickness of 30-40㎛ to secure chipping resistance, enhanced appearance of the top coat, adherence and improved corrosion resistance to the film. KCC's automotive primer is highly recognized among customers for its superior chipping resistance.
KCC has been supplying waterborne primers since 2006 after developing its eco-friendly technology.
Top coats are generally applied using the wet-on-wet method on base coat and clear coat to give appearance (gloss and leveling), pigmentation, weatherability, scratch resistance and chemical resistance. In general, base coat is applied on the back of the film with a thickness of around 15-20㎛. The global trend in automotive top coat technology is continuously shifting towards water-soluble formula. This shift was already commercialized 20 years ago but has been very slow in showing tangible results due to the delay in the enactment of VOC regulation in Korea and lack of facility renovation by the Automotive Industry. As the legalization of regulations and conversion to waterborne formula swiftly took place across Korea’s Automotive Industry, waterborne basecoat was applied for the first time in the mass manufacturing process by Hyundai Asan factory in June 2004 and converted to the entire lineup of passenger vehicles.
Clear coats are generally applied on the back with thickness of around 35-45㎛ using the wet-on-wet method of base coat and clear coat to give weatherability and scratch resistance.
The overseas technological trend in automobile clear coat shows improvements in appearance and energy-saving performance. The appearance standard requires the equivalent of global BIG5 finished-car makers and the cost down technology through lowering of the baking temperature is also one of the crucial needs of major finished-car makers.