Why do we use hydarted silica in toothpaste?
The latest trend of oral care products shows that precipitated silica occupies a large market share, which is mainly because the structure of precipitated silica can be adjusted by the change of control factors in the precipitation process to realize the diversity of its products, and the functions of thickening, friction and polishing can be widely used for different manufacturers.
Toothpaste thickener
The thickener in toothpaste can increase the viscosity and stabilize the glue body. Thickener can increase the apparent viscosity of paste, suspend heavier friction agent and polishing particles, prevent the separation of solid and liquid components in toothpaste, and the performance of thickener will directly affect the stability of toothpaste. Thickeners generally include refined bentonite, CMC, Hansheng gum, silica, etc.
Silica is mainly used as thickening agent of toothpaste to provide good pseudoplasticity and thixotropy for paste. Because the precipitated silica is a three-dimensional network structure composed of silicon oxygen tetrahedron, which can be highly dispersed in the aqueous solution, and make a large number of free water into the combined water in the network structure. When the network structure is damaged by external force, it can quickly become a suspension with low viscosity. Once the external force is eliminated, the network structure can be restored by the hydrogen bond of its surface hydroxyl In homogeneous plastic state, the viscosity increases gradually. In the process of making and using toothpaste, the false plasticity and thixotropy of the product are good, it can stand machining, and the components will not be damaged. At the same time, in the process of fluidization, the decrease of paste viscosity is beneficial to reduce the friction force of filling and improve the production efficiency. After static, the apparent viscosity of the product increases gradually, the shape of the tube is plump, and the extruded toothpaste has strong adhesiveness, while ensuring its storage Stability to meet the requirements of toothpaste shelf life. "
The change of tooth sound viscosity with time is one of the important indexes to investigate the stability of toothpaste and the rationality of paste formula structure.
Compared with the change of tooth viscosity without precipitated silica, the change of paste viscosity with precipitated silica is smaller, indicating that precipitated silica has a significant thickening effect.
At the same time, the specific surface of silica modifier is large, and it has strong adsorption on fragrance, making the fragrance of toothpaste soft and lasting, improving the glossiness of paste, and making the taste more delicate.