First, the name: silica, also known as precipitated hydrated silica, fine silicic acid. Second, the nature: This product is the main component of SiO2, its formula SiO2nH2O1, is white, amorphous fine powder, light, with the original diameter of 0.0003 cm or less. Melting point 1750 ℃, high insulation resistance, insoluble in water and acid, dissolved in caustic soda and hydrofluoric acid, the high temperature is not biodegradable, water absorption. This product is a reinforcing filler in rubber and plastics industry is widely used, it has a reinforcing effect in rubber after carbon black, added a vulcanized rubber silica main features are: high strength anti-up , elongation, good elasticity and heat resistance. This is suitable for natural rubber and synthetic rubber. Natural / SBR, truck tire natural / butadiene rubber tread is added instead of part 5 - 10 parts silica, carbon black, can improve tear strength of the compound, and can improve heat vulcanized rubber stable performance, the use of the formula, while adding a silane coupling agent (Si - 69) better. Three purposes: as rubber, plastics, paints and varnishes (Putty) and synthetic resin fillers, also used as an ink thickening agent, lightweight metal polishes, casting release agent and insulation materials used in the manufacture white pigment, models and pesticide carrier and adhesives.