Silica sol, also known as silicate water glass, is an inorganic polymer polymetasilicate colloid solution with water as the dispersed phase. It is odorless and tasteless, and has a considerable specific surface area. The particles themselves are colorless and transparent, which does not affect the true color of the covering. . The particles are mostly spherical single or multiple agglomerates. The diameter of the colloidal particles is generally 5-8NM, which is smaller than the particle size of the general emulsion by 0.1-10UM. The permeability is good, and it can be used wherever water can penetrate. With the evaporation of water, an SI-O bond is formed. This bond has strong rigidity and no deformability. Defects such as cracks and micropores are prone to occur in the process of coating film formation and dehydration. Therefore, organic polymers are introduced to make the organic polymers random and uniform. Distributed in the gap of the SI-O bond coating film to improve the toughness, impact resistance and water resistance of the coating film.

Silica sol can be mixed with water-based polymer compounds, such as polyvinyl alcohol (PVA), and polymer emulsions such as vinyl acetate, styrene-acrylic, pure acrylic, and silicone-acrylic. The modification of the emulsion by silica sol depends on the variety of the emulsion, and the dosage is also different. Silica sol can be mixed with a variety of organic polymers, so it can be used in a variety of coating systems, such as sealing primers, elastic coatings, waterproof coatings, low PVC coatings, ordinary interior and exterior wall coatings and non-high-gloss water-based wood coatings, etc. Both can modify the performance of the coating and cover up the defects of the coating itself.

Sealing primers, elastic latex paints, one-component waterproof coatings, etc. require coatings to have a certain permeability to the substrate, enhance adhesion, and the smaller the particle size of the film-forming material, the smaller the viscosity, and the better the penetration; A complete waterproof coating is formed on the surface, the particle size of the film-forming material is large, it is not easy to penetrate, and the waterproofness is good after the film is formed. Adding silica sol to prepare an organic-inorganic composite coating can meet such requirements.

Low PVC coating film has poor rigidity, high temperature rebonding and easy sticking, poor permeability and easy foaming. Adding a certain proportion of silica sol to the latex paint in the low PVC system can improve the rigidity of the paint film, improve the high temperature anti-sticking performance of the latex paint, and increase the washing resistance and alkali resistance of the paint film. But don't add too much. Generally, the coating has good alkali resistance, high washing resistance, good water resistance, and high freeze-thaw resistance.