Method for preparing white carbon black

Abstract

The invention relates to a method for preparing white carbon black. Silica solution is used as the raw material, wherein in the silica solution, the pH value is between 2.0 and 12; the proportion is between 1.14 and 1.3g / cm<3>; the content of SiO2 is between 20 and 40 percent; the water content is between 59.6 and 79.96 percent; the content of Na2O is between 0.04 and 0.40 percent; and the grain diameter of SiO2 colloidal particles is between 5 and 40nm. The method comprises the following steps: firstly putting the silica solution into a container and putting the container into a refrigerating room to cool until the whole silica solution is frozen; then taking the container out, and unfreezing the container to obtain a layer of flake-like transparent hydrous silicon dioxide solid deposition at the bottom of the container and water on the upper part of the container; and separating solid on the bottom of the container out and grinding and drying the solid to obtain the white carbon black. The method has simple process, low cost, universal equipment and small investment and high purity and easy grinding of the prepared flake-like silicon dioxide solid.

Description

technical field [0001] The invention relates to a preparation method of white carbon black. Background technique [0002] White carbon black is a kind of amorphous silica nanoparticles with a primary particle size of tens of nanometers, which forms micron-sized secondary particles through intermolecular interactions or other physical and chemical interactions, and accumulates countless secondary particles. Lightweight, fluffy powder. Because the primary particle size reaches the nanometer level, white carbon black is also called nano white carbon black. White carbon black has a nano-scale primary particle size, a large specific surface area, and high purity, thus exhibiting many properties: excellent reinforcement, thickening, thixotropy, extinction, dispersion, and insulation etc. It is widely used in rubber, plastic, coating, paint, medicine, paper making, electronics, daily chemical and other industries. [0003] At present, the preparation methods of white carbon bla...

AI Technical Summary

Problems solved by technology

This method also has disadvantages such as complex process, high requirements for reaction equipment, large particle size distribution range of the prepared white carbon black, and easy agglomeration of particles.

[0006] The Chinese Patent Gazette published an application document with the publication number CN101332994A and the title of the invention "A Preparation Method for Reinforced White Carbon Black". It introduced a preparation method for white carbon black, using sodium silicate as a raw material, and the preparation process Including sulfuric acid reaction, aging, heating and stirring, adjusting pH value, heating reaction again, filtering, beating, drying and other steps to obtain white carbon black, the process is very complicated

This method uses an organic solvent, the recovery of the solvent is difficult, and the obtained silica-like precipitate is not easy to dry, and it also has the disadvantages of high cost and complicated process.

[0008] In short, at present, there is still no simple, easy, and low-cost preparation method for high-purity, ultra-fine white carbon black at home and abroad.