Method for preparing dispersible ultra-fine silicon dioxide

Abstract

The invention discloses a method for preparing dispersible ultra-fine silicon dioxide. The method is characterized by comprising the following steps of: adding a liquid surface modifier into a precipitated silicon dioxide filter cake raw material; coating the surfaces of silicon dioxide particles in the precipitated silicon dioxide filter cake to form coating liquid by using the liquid surface modifier with strong stirring; and drying and activating the coating liquid to prepare a dispersible ultra-fine silicon dioxide powder product, wherein the surface modifier accounts for 1 to 50 percent of the mass of the silicon dioxide of the precipitated silicon dioxide filter cake. Experiment results show that: according to an SEM image of the dispersible ultra-fine silicon dioxide dispersed in an organic medium, the particle sizes of silicon dioxide particles are between 100 nm and 10 mu m; and the particle sizes of the silicon particles are between 100 and 400 nm and are distributed uniformly when a boric acid ester coupling agent is adopted.

Description

Technical field: [0001] The invention relates to a method for preparing ultrafine silicon dioxide powder by using precipitated silicon dioxide filter cake as raw material, in particular to a preparation method for ultrafine silicon dioxide powder dispersible in an organic medium. Background technique: [0002] Dispersible ultrafine silica has a wide range of applications as fillers or additives for rubber, plastics, coatings, etc. The silica powder prepared by the precipitation method generally has relatively large particles, uneven particle size distribution, and poor dispersion in organic media, which limits its application range. In order to obtain dispersible ultrafine silica powder, it is generally through pulverization and surface modification of silica powder. The disadvantages of this kind of dry crushing and modification are high energy consumption, high cost, serious dust pollution and the need to use special equipment, and the distribution of modifiers is not uni...

AI Technical Summary

Problems solved by technology

The disadvantages of this kind of dry crushing and modification are high energy consumption, high cost, serious dust pollution and the need to use special equipment, and the distribution of modifiers is not uniform enough, and the effect is not ideal

The use of wet methods to modify the surface of silica powder generally requires organic solvents as the medium, which is costly and the post-treatment process is relatively complicated.