The mechanism of improving anti-aging properties of silica in coatings mainly involves its unique physical and chemical properties and its multi-faceted effects on coating performance. The following is a detailed explanation of this mechanism:

1. Properties of silica

Silica is a general term for white powdered X-ray amorphous silicic acid and silicate products, which has the characteristics of high specific surface area, porosity, high temperature resistance, non-flammability, tastelessness, odorlessness and excellent electrical insulation. Its chemical composition is mainly SiO2·nH2O, in which nH2O exists in the form of surface hydroxyl groups, which makes silica have good hydrophilicity and surface activity.

2. The role of silica in coatings

Thickening effect: Silica can increase the consistency of the coating, thereby improving the rheology of the coating and making it easier to control during construction.

Filling effect: As a filler, silica can fill the gaps in the coating and improve the density and hardness of the coating.

Enhancing effect: Silica can interact with other components in the coating to form a more stable structure, thereby improving the strength and durability of the coating.

3. Mechanisms for improving anti-aging properties

Ultraviolet absorption and reflection: The high specific surface area and porous structure of silica enable it to absorb and reflect ultraviolet rays, thereby reducing the direct exposure and damage of ultraviolet rays to the coating and extending the service life of the coating.

Chemical stability: Silica has excellent chemical stability and is not easy to react chemically with other components in the coating, thereby maintaining the long-term stability of the coating.

Free radical scavenging: The active groups such as hydroxyl groups on the surface of silica can scavenger free radicals generated by the coating during the aging process, thereby slowing down the oxidative degradation process of the coating.

Enhancing the adhesion strength between the coating and the substrate: Silica can enhance the adhesion strength between the coating and the substrate, making the coating more firmly attached to the substrate, thereby resisting erosion and damage from the external environment.

In summary, the mechanism of silica in improving the anti-aging properties of coatings is mainly achieved through its ultraviolet absorption and reflection, chemical stability, free radical scavenging, and enhancing the adhesion strength between the coating and the substrate. These effects enable the coating to maintain excellent performance and appearance during long-term use and extend its service life.