After adding the appropriate amount of nano SiO2 to the interior and exterior wall coating, the anti-ultraviolet and anti-aging property of conventional coating are more than 2.5 times higher than before, and the anti-scrubbing properties can be increased by more than 10 times. Nano SiO2 has a strong UV shielding, and the UV shielding rate for the long-wave dark spot effect is up to 88%, while the UV shielding rate of the medium-wave red spot effect is 85%, and the shielding rate of the sterilized ultraviolet shortwave is still 70% ~ 80%. Therefore, nano SiO2 can play a role in shielding various kinds of ultraviolet rays in the coating, so as to make the coating anti-ultraviolet aging and thermal aging.
Compared with conventional materials, nano TiO2 has several unique properties, such as the large specific surface, strong magnetism, high surface activity, good thermal conductivity, etc. With many excellent properties, nanometer TiO2 has a broad application prospect in the coating field. The application environment of architectural coating especially exterior wall coating is relatively harsh. Ultraviolet, thermal energy, microorganism, water, air pollutants can cause the aging of the polymer in the coating, and ultraviolet aging is the most destructive. Therefore, the key to improving the weatherability of coatings is to reduce the degradation of ultraviolet light.
Nano ZnO is also an excellent anti-aging agent in coatings, adding a certain amount of nano ZnO can significantly improve the anti-aging performance of coatings. Compared with other nanomaterials, nano ZnO has a stronger ability to absorb ultraviolet rays. It has a better shielding effect on both long-wave dark spot effect and medium-wave red spot effect. Therefore, it is suitable to be used as the anti-aging agent in coatings.
Compared with traditional building coatings, the effects of nano calcium carbonate composite exterior wall coatings on stain resistance, thixotropy, washing resistance, water resistance, alkali resistance and aging resistance were significantly improved. When the mass fraction of nano CaCO3 slurry in the coating was 3 ~ 4%, the improvement of coating performance was the most obvious, and its washing resistance reached 75600 times.
Nano-clay is a kind of one-dimensional nanomaterials, so its specific surface area is higher than other nanomaterials, which ups to 700 ~ 800 m2 /g. Adding an appropriate amount of clay to the coating can greatly improve the mechanical and thermal properties of the coating. By modifying clay and adding it to the coating, the flexibility and impact resistance of the coating can be improved, and the optical properties of the coating can also be improved to a certain extent, so as to obtain a new type of architectural coating.