The refractive index of gas phase white carbon black is 1.46, close to that of film-forming resin, and does not affect the film's colour. It is an excellent matting agent to migrate to the surface of the paint film in the film-forming process, which can produce the expected roughness of the paint film surface and reduce the surface lustre. The extinction effect mainly depends on three properties of the product: pore volume ratio, particle size and surface treatment. The use of the gas-phase method of white carbon black should pay attention to match the thickness of the paint film in the thick film paint with excellent particles of the gas-phase process of white carbon black is unable to produce the appropriate roughness of the delicate surface, on the contrary, such as in the film paint with coarse particles of atmospheric phase method of white carbon black. However, its matting effect is perfect, but the surface most users will not accept the surface roughness of the paint film agent: gas phase white carbon black using methyl propylene silane surface treatment can be added to polyurethane coatings and play a role in friction resistance. Adding 5%-15% of the gas phase white carbon black, the friction resistance can be increased by 10% to 35%, and the rheological properties of the coating and the optical properties of the dry film are not negatively affected. Now, adding a large amount of gas-phase white carbon black should be considered an active filler rather than an additive. Anti-weathering agent: gas phase white carbon black has specific UV absorption and infrared reflection characteristics; by spectrophotometer test surface, adding gas phase white carbon black film UV shielding has been improved, among which the UVA(320-400nm) shielding rate reached 88%; The shielding rate of UVB(290-320nm) reaches 85%; The shielding of UVC(200-290nm) is still 70 ~ 80%. When the amount of gas phase silica is 3%, the UV shielding property of the film is the best. The ageing time of artificial accelerated climate ageing and artificial radiation exposure is increased from 250 hours (powder 1, colour change 2) to 600 hours (no powder, paint film, colour change, colour difference value 4.8). If you are looking for high quality, high purity and cost-effective Fumed silica, or if you require the latest price of Fumed silica, please feel free to email contact mis-asia.