Preparation method for suspended color silica particles used for toothpaste

Abstract

The invention provides a preparation method for suspended color silica particles used for toothpaste. The method comprises the following steps: (1) adding dilute sulphuric acid into a reaction tank and then carrying out stirring, and adding PEG and an aqueous sodium dodecyl sulfonate solution at the same time; (2) adding a water glass solution into the reaction tank, carrying out neutralization reaction under stirring, adding a food-grade pigment solution when a pH value of a material system reaches 3.0 to 4.0, and controlling the final pH value of the reaction to be 4.0 to 5.0; (3) continuously adding the dilute sulfuric acid into the reaction tank, carrying out uniform stirring and then adding the water glass solution, carrying out reaction under stirring, and until the material system is transfered into a gel, stopping adding of the water glass solution so as to obtain the gel; and (4) subjecting the gel to press filtration so as to obtain a gel filter cake, washing the gel filter cake so as to remove sulfate and residual PEG, and subjecting the washed gel filter cake to drying and crushing so as to obtain the silica particles. The silica particles prepared by using the method in the invention has certain hardness and small relative density, and has a suspension time of at least half an hour in a toothpaste modulation solution system.

Description

technical field [0001] The invention relates to a preparation method of suspended colored silica particles for toothpaste. Background technique [0002] Colored silica particles have a porous and large surface area structure, stable physical and chemical properties, and bright colors, so they are widely used in toothpaste and are a very important additive in toothpaste. Adding colored silica particles to toothpaste can not only give the toothpaste a new color and appearance, but also has good cleaning performance, so it is very popular. However, because the hardness of the colored silica abrasive particles currently on the market is generally high, the relative density is relatively high, and has not undergone any modification, so when the toothpaste solution system is prepared, the suspension time of the colored silica particles is too long. Generally, almost all of them will settle to the bottom of the solution within 5 minutes, greatly affecting the uniformity and stabil...

AI Technical Summary

Problems solved by technology

The silicon dioxide prepared by this patent has a narrow particle size distribution range and can be used as a toothpaste filler, but its hardness is relatively high and its density is relatively high. When the toothpaste solution system is prepared, the suspension time is short, and it will completely settle into the solution within 5 minutes. Bottom, poor dispersion uniformity and stability in the toothpaste system