Thickener in toothpaste has the effect of increasing viscosity and stabilizing the paste. Thickening agents increase the apparent viscosity of the paste, suspend heavier abrasives and polishing particles, and prevent the separation of solid-liquid components in toothpaste. The performance of thickening agents directly affects the stability of toothpaste. Thickener generally includes refined bentonite CMC、 Hansheng glue, silica, etc.
The total specific surface area of precipitated white carbon black is large, with strong adsorption capacity and more adsorbed substances. The particles are uniform, which is conducive to improving transparency. Due to its stable properties, non-toxic and harmless, it is a good toothpaste raw material. The silica used in toothpaste is mainly produced by precipitation method.
Silicon dioxide is mainly used as a thickener in toothpaste to provide good thixotropy for the paste. Precipitation method silica is a three-dimensional network structure composed of silicon oxygen tetrahedra, which can be highly dispersed in aqueous solutions and convert a large amount of free water into bound water in the network structure. When this network structure is damaged by external forces, it can quickly become a low viscosity suspension. Once the external force is eliminated, the network structure can be restored to a homogeneous plastic state through the hydrogen bonding of its surface hydroxyl groups, and the viscosity gradually increases.
In the industrial production of toothpaste, silica is generally synthesized by precipitation method using sodium silicate and sulfuric acid as raw materials. Precipitation silica is an amorphous structure, therefore, it is also called amorphous silica. In addition, it is a soft abrasive that does not damage enamel and has good compatibility with fluoride, making it an ideal toothpaste abrasive.
