Aug . 22, 2025 15:44
The coating and paint industry is constantly pursuing higher performance standards, such as better scratch resistance, longer weather resistance, and more stable glossiness. Silicon dioxide (silica/white carbon black) has emerged as a key functional additive in coating formulations, thanks to its excellent dispersibility, hardness, and optical properties. Unlike other inorganic additives, white carbon black can not only enhance the mechanical strength of coatings but also maintain the coating’s transparency and color stability, making it widely used in architectural coatings, automotive refinish coatings, and industrial protective coatings.
In architectural coatings, especially exterior wall coatings, white carbon black’s weather resistance and anti-pollution performance are highly valued. Exterior wall coatings are exposed to sunlight, rain, and dust for a long time, which easily leads to fading, chalking, and peeling. Adding 2-5% of precipitated white carbon black to the acrylic exterior wall coating formula can form a dense protective film on the coating surface. This film has strong UV resistance—after 2000 hours of artificial accelerated aging testing, the coating’s gloss retention rate is above 85%, and the color difference (ΔE) is less than 1.5, which is far better than the industry standard of 70% gloss retention and ΔE < 3.0. Moreover, the hydrophobicity of silica can reduce the adhesion of dust and rainwater on the coating surface, making the exterior wall easier to clean and maintaining its fresh appearance for a longer time.
To further illustrate the effectiveness of white carbon black in architectural coatings, let's take a real-world project as an example. A large commercial building in a coastal city faced severe challenges due to the harsh marine climate. The original exterior wall coating faded rapidly and suffered from significant chalking within a year. After applying a new coating formulation with 3% precipitated white carbon black, the building's exterior not only maintained its vibrant color but also resisted the erosion of salt spray and strong sunlight. Even after three years of exposure, the coating still looked as good as new, greatly reducing the maintenance costs for the building owner.
For automotive refinish coatings, the scratch resistance and glossiness of the coating are crucial factors affecting the vehicle’s appearance and resale value. Fumed silica, with its ultra-fine particle size and high surface activity, is an ideal additive for automotive clear coats. When added to the clear coat formula at a ratio of 1-3%, fumed silica can form a three-dimensional network structure in the coating film, which significantly improves the coating’s pencil hardness from 2H to 4H and reduces the scratch width by 50% under the same test conditions. At the same time, the excellent transparency of fumed silica ensures that the clear coat does not affect the color of the base coat—after curing, the coating’s glossiness at 60° can reach 95%, showing a mirror-like effect.
In addition to the quantitative data, the practical benefits of using fumed silica in automotive refinish coatings are also evident. A luxury car dealership noticed a significant reduction in customer complaints about minor scratches on newly refinished vehicles after switching to a clear coat with our fumed silica additive. The enhanced scratch resistance not only improved customer satisfaction but also increased the perceived value of the refinished cars, leading to higher resale prices. A well-known automotive refinish brand in the United States has adopted our fumed silica in their high-end clear coat products, and customer feedback shows that the coating’s scratch resistance has been improved by 40%, and the service life of the coating has been extended from 3 years to 5 years.
In industrial protective coatings, such as coatings for steel structures and chemical equipment, white carbon black’s chemical resistance and adhesion are essential. Steel structures in marine environments are prone to corrosion by salt spray, and chemical equipment is often in contact with acidic or alkaline media. Adding precipitated white carbon black modified with silane coupling agent to the epoxy protective coating can enhance the coating’s adhesion to the metal substrate—the pull-off adhesion strength can reach 10MPa or more, which is 30% higher than that of coatings without white carbon black. Additionally, the silica particles can block the pores in the coating film, preventing the penetration of corrosive media, thus extending the corrosion resistance period of the steel structure from 5 years to 8 years.
Let's consider a chemical plant as an example. The plant's storage tanks were constantly exposed to corrosive chemicals, and the previous coating failed to provide adequate protection, resulting in frequent repairs and downtime. After applying an industrial protective coating with our modified white carbon black, the storage tanks showed remarkable resistance to chemical corrosion. The coating remained intact even after continuous exposure to highly acidic substances for over a year, ensuring the safe operation of the plant and reducing the overall maintenance costs.
Our company offers a full range of white carbon black products for the coating industry, including hydrophilic and hydrophobic grades. The hydrophobic silica is modified with dimethyl dichlorosilane, which has excellent compatibility with organic coating resins such as acrylic, epoxy, and polyurethane, avoiding the problem of sedimentation and agglomeration in the coating. All our silica products have passed the SGS testing, meeting the environmental protection requirements of RoHS and REACH. The particle size of our products can be customized according to the coating’s application scenario—for high-gloss coatings, we provide silica with a particle size of 5-10nm; for matte coatings, we offer products with a particle size of 50-100nm to adjust the coating’s glossiness to the desired level.
