Advancements in the automobile industry have never failed to baffle us. However, no car would ever hit the market without the finishing touch of coatings. The additives provide automobiles a unique appearance, which makes them desirable for customers.
Researchers have spent years after years in customizing color and thus offer a better, aesthetic appearance to interior and exterior of vehicles. According to customer demand, the industry launched novel paint additives; some offered high sparkle finishes and other chromic colors and mirror-like finishes to automobile components.
So, what are paint additives anyway? In the simplest language, additives are spices and flavors of a coating. Today’s coatings are made up of complex formulae including emulsifiers, thickeners, pigments, dispersants, photo-stabilizers, leveling agents, and several different additives.
All these additives are added to serve one purpose: to improve the inherent properties of the resin. Moreover, pigments offer uniform appearance in coatings while improving the durability of the coating.
The global automotive paint additive market was $3.29 billion industry in 2019, and according to Allied Market Research, it is expected to reach touch $5.63 billion by 2026, growing at a CAGR of 7% from 2019 to 2026. The increase in automobile production and the advent of eco-friendly automotive paint additives are the prime driving factors for the market.
Paint additives: Creating a unique look with each pigment
The collaboration of coating formulators and pigment suppliers results in commercialized and unique pigments that offer aesthetic colors that compliment the bodyline of new automobiles. This is the prime reason behind the growth of the effect pigments segment of the automobile paint additive segment.
The neutral colors including black, white, and silvers have been dominating the automobile color palette, on the other hand, the rich, deep colors such as oranges, reds, greens, and blues have made their way in the automotive world.
Thanks to special effect pigments, automotive can stand out among others as it offers modernity that customers demand. Similarly, designers are searching for new ways to develop a value-added appearance by boosting the reflectivity of metallic finishes while keeping the smooth, non-sparkling appearance unaltered.
Apart from the special effect pigments, flow & leveling additives are one of the vital class of paint additives. A number of defects can occur in the forming film such as fisheyes and orange peel.
The important parameter in the development of these defects is the localization of surface tension gradients. This forms the defect and remains until the film dries. However, surfactant-based flow & leveling agents operate by reducing the surface tension of carrier liquid and increases the flow while reducing the strength of the gradients.
Demand for anti-fouling paints for automotive
Considering the political atmosphere across the globe, many customers demand anti-fouling, anti-graffiti paints. In such cases, surface-active agents often help. The additive designers prefer silicone a.k.a fluoroalkyl surfactants that offer flow & leveling along with wetting & release.
A slightly modified silicone polymer or even hydrocarbon is regarded as the best way to achieve the surface effect. Additionally, the surfactants are carefully developed to be seamlessly miscible with the binders and thereby reducing the potency of low-surface-energy materials at the interface.
Needless to mention oil and water do not mix with each other, but the pairs of water and silicone oil and water and fluorocarbon oils are also immiscible. Thus, designers rely on these release additives that are somewhat chemically close to pure silicon. In fact, there is an art in balancing the quantity of these chemicals to prevent defects and offer perfect flow & leveling.
Increasing demand for foam control agents
Similar to flow & leveling additives, defoamers are also widely in demand. Surfactants such as flow & leveling agents migrate the air-liquid interface, which develops due to mechanical agitation of the coating. However, it does not possess the ability of defoamer.
In simple language, a defoamer causes the foam to break. For instance, upon the addition of alcohol to stable foam, the foam breaks. The defoamer is a low-viscosity and low-surface-tension molecule. In addition, it quickly displaces the profoamer molecules and breaks down the foam.
However, the defoamer is regarded as a complex additive. It works by migrating to interface and spreading and spanning the air gap to breach the interface. The well-known defoamers are silicone-based and are often used to reduce PPM levels.
Need for mar & stain resistance additives
Stain resistance is vital in automobile paints. The mar & stain resistance of the paint is improved by low-surface-energy materials at the air-solid interface. The mar resistance is a result of the slipperiness of the surface. Furthermore, with the use of mar & stain resistance additives, the materials that damage the coating slide across the surface.
The mar & abrasion resistance enhancement is obtained by improving cross-linking from additives including organo-functional tri-alkoxy silanes. These additives work similarly to high-functional reactive polymers.
On the other hand, stain resistance enhancement is achieved owing to poor miscibility and low surface energy of agents at the interface.
In developing automobile paints, it is vital how such additives are aligned at the surface, especially if one is looking for stain resistance. A slight difference in molecular architectures can give you a completely different performance.
The processes of developing additives are complex and play a vital role in the automobile industry. There are a plethora of additives available in the market and one begs the question of why not develop one additive that can fulfill multiple requirements.
Some additives work better to prevent overcoat problems but fail to reduce surface tension. However, for now, we don’t have one novel paint additive that satisfies every demand. And that’s where the R&D is focused and opportunities lie in the market.
