New Elastomeric Cool Roof Coatings Solution
Nouryon launched a new solution for the building and construction market that boosts the effectiveness of energy-saving ‘cool roof’ coatings by improving their ability to reflect light and enhancing their self-cleaning properties. The new concept combines Nouryon’s Expancel® expandable thermoplastic microspheres, which reflect light, and its Levasil® colloidal silica, which improves the performance of the coatings.
Use of reflective cool roof coatings is on the rise in warmer climates, where they help to reduce the need for air conditioning and in turn reduce energy consumption. When produced with Nouryon’s Expancel microspheres, cool roof coatings can bring down the external surface temperature of a building by as much as 15 degrees Celsius.
“In addition to temperature reduction, it’s also important that the coating adheres well to the roof surface and expands and contracts with it as temperature levels change,” says Patrick Wilhelm, Vice President of Colloidal Silica at Nouryon. “Combining Expancel with Levasil colloidal silica improves the adherence and mechanical properties of the coating without sacrificing elasticity and flexibility, and thanks to its self-cleaning properties it also extends the life of the coating,” he said.
“We have already made this offering available in Asia, Europe and Mexico and have achieved great results, receiving nothing but positive feedback from our customers,” Wilhelm added.
Nouryon will now offer this technology to customers in the US, teaming up with distributor CoadTech – Cool Additives Technology. CoadTech has experience with both product lines and has a long-standing relationship with Nouryon as a distributor for Expancel.
“Creating this technology for the coatings market reflects Nouryon’s strategy of increasing our focus on products that drive profitable growth, while delivering solutions that address the challenges facing our society today,” said Johan Landfors, President of Technology Solutions at Nouryon. “We are pleased to be part of a solution that offers significant sustainability benefits to end-users.”
Expancel is a powerful ally in both roof coatings and in wall coatings. The microspheres are optimal for developing highly flexible exterior coatings and cool roof coatings used on concrete and similar materials.
Solar reflectance
Comparing Expancel Microspheres with other fillers commonly used in cool roof coatings, you’ll find that most of them are not only heavier, but also offer less protection from the sun. That’s because Nouryon’s microspheres are packed with powers that include high solar reflecting and thermal insulating properties. Expancel’s proven track record for reflecting visible and near-infrared light, and its resilient nature, makes it a perfect ingredient for formulating an elastomeric cool roof coating with superior quality.
In warm climates, air conditioning takes the lion’s share of total energy consumption, with percentages around the 70 mark in residential areas. These tiny microspheres make it possible to reduce this number by minimizing the need for turning up the AC when it’s hot. Elastomeric cool roof coatings with Expancel can bring down the external surface temperature of a building by as much as 15°C/27°F. Not only does it help keep things cool inside, it also makes relying on energy-draining air conditioning a whole lot less. In fact, by applying an Expancel-formulated coating to the metal roof of a large, one-story commercial building, cooling energy consumption was reduced by more than 40%.
The graph above compares spectral reflectance of binders with TiO2, CaCO3 and Expancel Microspheres (WE). From this graph it is obvious that by replacing inorganic filler with Expancel, the hiding power as well as the total solar reflection of the coating improve. This also makes the coating appear whiter.
Elasticity in wall and roof coatings
When compared to Expancel, mineral fillers are heavier and have a higher specific surface area which requires more binder. The spherical shape of Nouryon’s microspheres require less binder. Its reciliency also allows you to up the PVC without jeopardizing the coating’s elasticity. This leaves the coating to maintain its elasticity, acting as an impenetrable barrier that protects against cracks. All the while, the coating is able to breathe. The elasticity of elastomeric coatings filled with Expancel has proven to be more superior when compared to other alternatives – even when tested in severe weather conditions. This together with the closed cell structured microspheres makes Expancel the ideal addition in water proofing coatings.
