In paint and coating applications, precipitated silica is a widely recognized and efficient matting agent, but their functional characteristics depend on many factors, such as particle size, particle size distribution, particle morphology, etc. If the above factors can be reasonably controlled, the performance and effectiveness of precipitated silica will be greatly improved.
The Evonik coating additives business team has recently launched the SPHERILEX® silica wet chemical production process. This process can give silica a unique spherical particle morphology, allowing it to play a new advantage in coating applications. In this wet reaction process, manufacturers can control many characteristics of the final product, including pH, surface area, (intra-particle) pore volume, pore size distribution, and other structural or morphological characteristics.
With this technology, Evonik has launched three new silica products for paint and coating applications: SPHERILEX®DP-0111, SPHERILEX®DP-0112 and SPHERILEX®DP-0115.
For modern architectural coatings, abrasion resistance and wet abrasion resistance are the key technical problems, and also an important factor that determines their performance. Given the filler or formulation options currently available on the market, there is limited space for formulators to respond to challenges and achieve product differentiation.
The particle morphology of the filler and the corresponding coating surface profile are closely related to these performance characteristics. Benefiting from new technological research results, winning innovative synthetic silica has the following advantages:
• Unique spherical particle morphology;
• Narrow particle size distribution;
• Very small surface area and very low porosity
In addition, under the influence of regulatory requirements and other challenges, the raw materials that can be used for coating formulations are gradually restricted. For example, solvents can help soften the polymer and promote its free flow, so as to coat and wet the pigment particles in the coating, thereby improving the bonding ability of the polymer resin. However, in order to reduce VOC emissions, the market supply of these solvents is gradually shrinking, so formulators must seek other methods to minimize the need for polymer resins in the solid raw materials in their formulations.
Evonik's new SPHERILEX® technology can not only meet the above coating formulation challenges, a series of excellent performance and unique functions of silica and silicate products also help formulators realize the new value of synthetic silica technology.