Research on the application of calcium carbonate in sealant
Research on the application of calcium carbonate in sealant
The prepolymers of sealants are relatively weak, so fillers are often added during the preparation process to enhance their properties. Common fillers include calcium carbonate, quartz powder, carbon black, titanium dioxide, aluminum hydroxide, talc, kaolin, clay, etc. Among them, calcium carbonate has become one of the most commonly used fillers due to its multiple particle size classifications, flexible surface treatment methods, high whiteness, mature production technology and low price.
The application of calcium carbonate in sealants has significant advantages. It can increase the volume of the sealant and improve its tensile strength, wear resistance, tear resistance and hardness. Calcium carbonate usually accounts for 10% to 70% of the sealant formula. Due to its widespread use in sealants, the industry's requirements for calcium carbonate products have also increased, specifically in terms of product quality stability, fluctuation control of performance indicators, good reinforcing effects and processing performance, and reasonable prices. and certain economic benefits and other requirements. At present, domestic calcium carbonate products have gradually overcome technical difficulties and gradually replaced imported products with high-quality products, occupying a place in the market and promoting the progress of the entire calcium carbonate industry. The development of the sealant industry is closely related to the calcium carbonate industry and complement each other, jointly promoting technological innovation and application.
Calcium carbonate products mainly include three categories: nano calcium carbonate, light calcium carbonate and heavy calcium carbonate. R&D personnel need to reasonably select different types of calcium carbonate based on the different performance requirements of the sealant. For example, when preparing a potting type or sealant with good leveling properties, you can choose calcium carbonate with larger particle size and better fluidity; while in sealants that require higher thixotropy, you should choose calcium carbonate with larger particle size. Small and surface-treated calcium carbonate; for sealants that require high hardness, the amount of calcium carbonate can be increased appropriately; if the extrudability of the sealant needs to be improved, a compound of nano calcium carbonate and heavy calcium carbonate can be selected. For use. In addition, factors such as calcium carbonate particle size, oil absorption value, moisture content, surface activation method, and activator used will also significantly affect the physical and mechanical properties of the sealant.
