White carbon black is an older variety of silicon compounds. In the mid-1930s, Germany, the Soviet Union, the United States and other countries began to develop it. By the end of the 1940s, it entered industrial production. In the 1980s, the total production capacity reached 700,000 to 800,000 tons/year. my country started in the 1960s. In the 1980s, there were two thousand-ton factories with an annual output of only 5,000 to 6,000 tons. Moreover, there were few varieties, poor quality, high energy consumption, and no series. Therefore, the task of developing new products and developing application areas is very arduous.
1 Physical and chemical properties
The appearance is a white, highly dispersed amorphous powder or flocculent powder, and it is also processed into granular form as a commodity. The specific gravity is 2.319 to 2.653, and the melting point is 1750℃. It is insoluble in water and most acids. After absorbing moisture in the air, it will become aggregated fine particles. It can be dissolved in caustic soda and hydrofluoric acid. It is stable to other chemicals, resistant to high temperatures, does not decompose, and does not burn. It has high electrical insulation and porosity. It has a large internal surface area and has a large dispersion force in raw rubber. The surface-modified hydrophobic silica is easily soluble in oil. It is used as a reinforcing filler for rubber and plastic, which can significantly improve the mechanical strength and tear resistance of the product. Due to different manufacturing methods, the physical and chemical properties and microstructure of silica are different, so its application fields and application effects are also different.
2 Uses
Silica has a wide range of uses, and different products have different uses. Here is a summary as follows: It is used as a good reinforcing agent for synthetic rubber. Its reinforcing performance is second only to carbon black. If it is ultra-fine and properly surface treated, it is even better than carbon black. It is especially suitable for the manufacture of white, colored and light-colored rubber products. It is used as a thickener or thickener, a blending agent for synthetic oils and insulating paints, a matting agent for paints, a thixotropic agent for electronic component encapsulation materials, a precipitant for fluorescent powder when coating fluorescent screens, a filler for color printing plates, and a release agent for casting. Adding it to resin can improve the moisture-proof and insulation properties of the resin. Filling it in plastic products can increase the anti-slip and oil resistance. Filled in silicone resin, it can be made into plastics that can withstand temperatures above 200°C. In the papermaking industry, it is used as a filler and surface ingredient for paper. It is also used as a carrier or dispersant for insecticides and pesticides, an anti-caking agent, a liquid adsorbent, and a lubricant.