Method for preparing nontoxic colored silicasol

Abstract

The invention provides a preparation method of non-toxic colored silica sol. First, the colorless silica sol is prepared, the pH of the colorless silica sol is adjusted to neutral, and then the colorless silica sol and the non-toxic colored metal ion aqueous solution are mixed to adjust the mixing The pH value of the solution is 2-4, reacted under the condition of heating and stirring for 6-10 hours, then filtered and concentrated to obtain non-toxic colored silica sol. The invention overcomes the colorless and transparent defect of the existing silica sol, and adds non-toxic non-ferrous metal particles in the process of preparing the silica sol by the silicon dissolution method, so that the silica sol generated in situ has a bright color. The particle size of the prepared silica sol is 5-37nm. The silica sol produced by the method of the invention has the characteristics of stable properties, non-toxicity, bright color and strong colorability, and can be widely used in the preparation of non-toxic and colored medical appliances, food packaging films 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