Silica with low particle size and high dispersion and high transparency for toothpastes and preparation method thereof

Abstract

The invention belongs to the technical field of silica for toothpastes, and particularly relates to silica with low particle size and high dispersion and high transparency for toothpastes and a preparation method thereof. The preparation method comprises the following steps: S1, adding polyethylene glycol to a sodium silicate solution, stirring and dispersing the solution uniformly to obtain a sodium silicate mixed solution; S2, adding a sodium sulfate solution into a reaction tank, starting stirring, and performing heating; S3 under stirring, simultaneously dropwise adding the sodium silicatemixed solution and a sulfuric acid solution, controlling a pH value to 8.5-9.5, controlling a temperature, continuously dropwise adding the sulfuric acid solution after addition of the sodium silicate mixed solution is completed, stopping addition of the sulfuric acid solution when pH is 4.0-5.0 to obtain silica; and S4, performing pressure filtration, washing and spray-drying to obtain silica for toothpastes. The method is simple in process, the prepared silica has small particle size, good dispersion and high light transmittance, and good application in toothpastes is satisfied.

Description

technical field [0001] The invention belongs to the technical field of silica preparation, and in particular relates to silica for toothpaste with low particle size, high dispersion and high transparency and a preparation method thereof. Background technique [0002] Silica is very stable due to its physical and chemical properties, acid and alkali resistance, high temperature resistance, no pollution to the environment, good cleaning performance, friction, and does not damage teeth, and has good compatibility with raw materials in toothpaste, and is compatible with fluorine High durability, so it replaces calcium carbonate and other raw materials as the abrasive and thickener of toothpaste. [0003] At present, the silica particles for toothpaste prepared by the precipitation method mainly have the following problems: [0004] 1. The particle size of silica is too large, reaching 20-40 μm, and it needs to be crushed to a particle size of 8-15 μm to meet the good applicatio...

AI Technical Summary

Problems solved by technology

[0004] 1. The particle size of silica is too large, reaching 20-40 μm, and it needs to be crushed to a particle size of 8-15 μm to meet the good application in toothpaste. This will not only increase the production cost, but also easily destroy the particle itself. shape, reduce the original performance of the product, and cause product waste

[0005] 2. The surface activation energy of silica particles is high, and the particles are easy to interact with each other to form agglomerations, resulting in a decrease in dispersion performance

[0006] 3. The light transmittance of silicon dioxide is low, which makes the light transmittance of the liquid phase system and the solid phase system of the paste quite different, and it is difficult to obtain a toothpaste with high transparency.

This method can obtain silica with low particle size distribution and high dispersibility, but the reaction temperature of this method is high, and sodium pyrophosphate and dodecyl dimethyl benzyl ammonium bromide need to be used as reaction aids, resulting in The process is complicated and the cost is high, which is not conducive to popularization and application

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