Method for preparing nontoxic coloured silicasol

Abstract

The invention provides a preparation method for nontoxic colored silica sol, which comprises the following steps: firstly, the colorless silica sol is prepared, and the pH of the colorless silica sol is adjusted into neutral, and then the colorless silica sol is mixed with the nontoxic colored metal ionized water solution; the pH value of the mixture is adjusted to 2 to 4, and the mixture is reacted for 6 to 10 hours under the conditions of heating and stirring, and then is filtered and concentrated for producing the nontoxic colored silica sol. The invention overcomes the shortcomings of colorlessness and transparence existing in the prior silica sol; the nontoxic colored metallic particles are adopted to make the generative silica sol be colorful during the process of preparing the silica sol with silicon dissolution method. The granularity of the prepared silica sol is 5 to 37nm. The silica sol which is prepared with the method of the invention has the advantages of stable quality, innocuity, bright color and strong colouration, thereby the invention can be widely used in preparing nontoxic colored medical equipment, food package film and other products.

Description

technical field [0001] The invention relates to a preparation method of silica sol, in particular to a preparation method of nontoxic colored silica sol. Background technique [0002] Silica sol is a colloidal solution of polymer silica particles dispersed in water or organic solvents. It is odorless and non-toxic, and its appearance is mostly milky white or light blue transparent solution. Silica sol has many excellent properties, such as greater adsorption, better cohesiveness, good temperature resistance, "high dispersibility", "good wear resistance" and good " Translucency", etc., so it can be used as a good "dispersant", "preservative", "flocculant", "coolant" and special "optical material". At present, silica sol has been widely used in fiber, fabric, paper, rubber, coating, paint, ceramics, refractory coating, floor wax and other industries. In addition, it is also used in the polishing of semiconductor silicon wafers, water treatment, mineral flotation and beer, wi...

AI Technical Summary

Problems solved by technology

The patent application number is 200610155112.x, and the patent application titled "a preparation method of monodisperse silica sol" discloses a preparation method of silica sol, which uses silicon powder under the action of heating and catalyst Dissolved in deionized water to prepare silica sol, but because it is dissolved in deionized water, the obtained silica sol is colorless, which cannot meet the demand in applications that require coloring

[0003] The existing silica sol itself is colorless and transparent, although it does not affect the covered object in use, but in the occasion where color is required, the existing silica sol products have the defect that they cannot be colored