Inorganic pigments from LANXESS are used to add color to sand-surfacing for roofing materials such as roofing felt. They not only add color but give the roof an attractive coarse structure.

Bituminous roof felts are often colored by scattering colored sand onto the still warm and tacky surface. Since the roofing materials need to be very durable, the colorfastness of the colored sand used must be correspondingly high. This is not only dependent on the light fastness and weather stability of the pigments but also on the stability of the binder used to fix the pigment to the sand particles. As a rule, organic binders do not satisfy the requirements specified so inorganic binders are nearly always used nowadays.

In order to achieve a weather stable fixing of the pigments to the sand particles, the inorganic binders need to be used at temperatures between 600 and 1.000 °C. Therefore, the pigments must have very high heat stability. Apart from the Colortherm® Green pigments and the Bayferrox® red product range, LANXESS also offers additional special grades for this application.

The Global Competence Center Construction will gladly answer individual customer inquiries with respect to this field of application or provide further information about LANXESS pigments.