Application of White Carbon Black in Paint
When it comes to the application of silica, first of all, we will think of the rubber industry.It is intended to be used as a reinforcing agent in the rubber industry, but the application of silica has been very extensive so far. Today, let's look at its application in the paint industry.
As the refractive index of amorphous silica is 1.46, it is similar to most resins used in the coating industry.
The refractive index is similar, so amorphous silica has good optical properties when used in varnish, and is the first choice of high-grade paint matting agent.
When the paint film containing white carbon black matting agent is used, the matting agent particles can be evenly distributed in the film, when the incident light reaches the uneven surface of the paint film, diffuse reflection occurs, that is, scattering occurs to produce low gloss matt and matt appearance. So what are the factors that affect the extinction performance of silica? The main reason is that the average particle size of silica and its particle size distribution will affect the gloss of the coating.
① For the silica matting agent with a given particle size, its matting efficiency will increase with the increase of pore volume:
② When the coating and film thickness are given, the matting effect is the best when the particle size of the matting agent corresponds to the dry film thickness of the coating:
③ The narrower the range of particle size distribution, the higher the extinction efficiency.
Silica can be easily dispersed by surface treatment with organic coating (mainly polymer wax)
The matting agent can improve the scratch resistance of the coating film and prevent the hard precipitation of the coating during storage by applying it in the coating. If the white carbon black matting agent with high porosity, optimum particle size distribution and suitable surface treatment is used, the best matting effect can be obtained. Therefore, foreign silica matting agents are developing towards the direction of large pore volume, easy dispersion, high transparency, low dust and surface treatment. It is believed that in the near future, silica will be better applied in coatings.