Cool roofs and hollow microspheres
A recently published technical article describes how hollow microspheres used as filler material can enhance a number of coatings properties. Among others they can reduce the demand for air conditioning.
The paper from European Coatings Journal 5/2019 describes how spherical micron-sized fillers enhance the elastic properties of a coating at a given pigment volume concentration relative to a standard inorganic filler.
Elastomeric waterproofing coatings are primarily applied to roofing materials to protect and seal them. This kind of coating is often pigmented white to refect solar radiation.
Enhanced reflection coatings
The paper shows that glass microspheres as well as thermoplastic microspheres can actively enhance the reflection of such coatings in the near infrared region of the solar radiation spectrum. According to the technical article there is also an apparent increase in elongation at break of films cast from formulations in which CaCO3 was replaced by hollow thermoplastic microspheres, with 100% replacement causing the greatest elongation.
This property is important for roof coatings to accommodate for the large temperate cycles that roof coatings have to withstand. The effect on elongation at break is less pronounced for the films filled with glass microspheres than those filled with thermoplastic microspheres
The authors of the article will give more details on the effect of microspheres during a live webinar on June 4 at 15:00 h CET.
