The demand for elastomeric white roof coatings has grown rapidly and so has the competitive landscape. Manufacturers are looking to optimize their formulas by cutting costs and increasing performance. In elastomeric roof coatings, coverage and good mechanical properties are key for long-term success, and TiOis widely used for this reason. Its light scattering properties and high whiteness/brightness achieve excellent opacity and solar reflectance; and it also aids in the mechanical properties in a coating providing long term resistance. The unfortunate part is that TiOis also the most expensive white inorganic pigment available today. We asked if we could help customers reduce TiO2 in their roof coating formulas without sacrificing performance.

The result: Azelis CASE successfully created a roof coating formula which demonstrates that you can remove 15% (by volume) of the TiO2 in a formulation while maintaining performance as defined by ASTM D6083 protocol and color.


  • Azelis Labs conducted this study using an internal Starting Point Formulation containing the water based acrylic emulsion, Acronal NX 3587.
  • The TiOextenders were evaluated at 2-3 replacement percentages ranging from 5-20% of TiO2
  • All of the roof coating formulations were tested under the ASTM D6083 testing protocol. (Mandrel bend was excluded since the resin is known not to meet the specification for either Type I or II.)
  • Additional testing: Emissivity, Solar Reflectance, Solar Reflective Index (SRI), and color change.
  • All formulations were kept at the same PVC and volume solids.
Physical Properties Specification Control Azelis Formula
 % Replacement of TiO2 15
Viscosity 85-141 KU 115 110
Density, lbs/gal  12.53 12.45
Permeance <50 perms 30.0 20.0
Water Swelling <20% 4.0% 7.2%

Performance Results

Strength and Elongation - Initial
Srength and Elongation - 1000hrs
Adhesion - Dry
Adhesion - wet
Tear Strength
Initial 1000 hrs weathering
ΔL  -0.31 -0.30
Δb 0.13 0.25
ΔE 0.34 0.39

Table 1: Color Retention

Column 1 Control – Initia Azelis – Initial Control* – 1000hrs Azelis – 1000hrs
Emissivity 0.90 0.91 0.885 0.88
Solar Reflectance 0.858 0.850 0.844 0.840
Solar Reflectance Index 108 107 106 105

Table 2: Emissivity and Solar Reflectance

*Color Change was measured relative to the control which contained only TiO

Interested in learning how you can reduce your formulation costs?  Contact us!

Full raw material list and formulation details of the Azelis White Roof Coating Formula is available from your Azelis representative or via our iChat service.

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