Common hydrophobic agents and their usage methods

Common hydrophobic agents include:Fatty acid metal soap, paraffin wax, polyolefin, organosilicon resin, fluorocarbon polymer.

The surface coated with organic silicon resin and fluorocarbon polymer has excellent hydrophobicity, with a contact angle of up to 140°~160°。

The hydrophobicity of hydrophobic agents depends on the arrangement and orientation of hydrophobic molecules on the substrate, as well as the degree of adhesion between hydrophobic molecules and the substrate.

Polysiloxane has good adhesion to substrates, especially on silicate substrates containing the same amount of silicon. Polysiloxane has excellent wetting, spreading, and adhesion properties, and can exhibit excellent results even with very thin coatings. In addition, polysiloxane hardly affects the porosity of building materials. After coating with polysiloxane hydrophobic agents, liquid water cannot infiltrate and flow into the micropores of the substrate, but the permeability of air and water vapor remains unchanged.

There are two ways to use hydrophobic agents:As an impregnating agent and an additive for water-based coatings. 

Polysiloxane impregnating agents can also be used as base coating agents, as they easily penetrate into the micropores of building materials. This not only prevents the migration of water and inorganic salts inside the building materials, but also enhances the adhesion of the topcoat. Even after the topcoat is damaged, it can protect the building materials.

 Adding hydrophobic agents to the coating can accumulate on the surface of the paint film during the drying and film-forming process, forming a hydrophobic layer, which can also have hydrophobic and self-cleaning effects.