Special extinction powder for water-based coating and preparation method of special extinction powder

Abstract

The invention discloses special extinction powder for a water-based coating and a preparation method of the special extinction powder. The preparation method comprises the following steps: adding water and silicon dioxide powder into a reaction kettle, and adjusting the pH value of the solution to be 8-11 by using water glass I; uniformly stirring, and then adding water glass II and a sulfuric acid aqueous solution into the reaction kettle, wherein the concurrent flow time lasts for 30-120 min, and the concurrent flow temperature is 30-90 DEG C; after concurrent flow reaction is finished, adding a modification aid into the reaction kettle; adjusting the pH value of the solution in the reaction kettle to be 9, and then aging for 0.5-3 h at the temperature of 90 DEG C; adjusting the pH valueof the solution in the reaction kettle to be 2.5-3, and then reacting for 30 min to obtain a reaction product; and filtering the reaction product, washing the reaction product until the conductivityis less than 100 mu S, drying the reaction product at the temperature of 100-200 DEG C, and crushing the reaction product to obtain the special extinction powder for the water-based coating. The silicon dioxide extinction powder prepared by the invention has high compatibility with resin, and the water resistance and transparency of a water-based coating paint film are enhanced.

Description

technical field [0001] The invention belongs to the technical field of coatings, in particular to a special matting powder for water-based coatings and a preparation method thereof. Background technique [0002] Traditional oil-based paints contain a large amount of volatile organic solvents (VOC). The discharge of a large amount of VOC not only causes great damage to the environment, but also endangers human health. The water-based paint uses green and environmentally friendly water as a solvent, which can greatly reduce the harm of volatile organic compounds (VOC) to the environment and the human body. [0003] In recent years, environmental problems have become more and more prominent, and smoggy weather has become a part of daily life. Therefore, the country has issued a series of policies on environmental protection, and a large number of heavily polluting paint and furniture factories have been shut down due to environmental protection problems. Therefore, it is bound...

AI Technical Summary

Problems solved by technology

However, compared with oil-based paints, water-based paints also have certain disadvantages in terms of performance: slower drying speed, poor film resistance

[0004] During the synthesis process of water-based resin, in order to make the resin compatible with water and form a homogeneous water-based resin system, a large amount of surfactants have to be added; and these surfactants will always exist in the water-based system, in the paint film After drying, due to the presence of these highly hydrophilic surfactants, the water resistance of the paint film of the water-based paint is greatly reduced

In addition, since most water-based resins exist in the form of emulsion, the curing of the paint film is based on the physical connection of the emulsion particles with a certain intermolecular force, lacking the effect of chemical bonds, so that the cross-linking density of the paint film is low. Reduced paint film resistance

After the ordinary silica matting powder is added to the water-based resin system, due to its poor compatibility with the resin, it is mixed between the resin and the resin after dispersion, making the intermolecular force that is not strong enough to become weaker , thus further reducing the cross-linking density of the paint film, making the paint film resistance even lower

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