It is known in the art to use infra-red (IR) reflecting paints in order to reduce the temperature rise on a roof or wall which is exposed to solar radiation.
When the sun shines on the surface of a building such as walls or roofs the temperature of the exterior walls and roofs will increase. Eventually the accumulated heat will depending on the level of insulation transgress to the interior such that also the interior of the building will be heated from the IR radiation. This phenomenon is due to the fact that the IR portion of the solar radiation (high-wave lengths from 700-2,500 nm) is absorbed by the exterior surfaces such as roofs and walls of the building and eventually transmitted to the interior of the building.
In order to lessen this impact the walls or roofs may be painted white or made from light coloured materials as the lighter colours are more effective in reflecting also the IR spectrum. However, most colours contain carbon black to a higher or lesser degree depending on the nuance/hue of the colour, and as such due to the carbon black will absorb IR radiation across the solar spectrum.
In this context it should be noted that by IR reflective properties is meant that the paint composition when dry and applied to a building surface such as a roof or a wall will reflect more of the sun's radiation and thereby give rise to a lesser temperature increase than a non IR-reflective paint of the same colour.
It is clear that the more reflective the coating is, the lower the temperature of the panel surface will become.
A further aspect is the environmental aspect in that the use of solvents creates a host of hazards for the people applying the paint compositions as well as a potential pollution problem when discarding the remains of leftovers of the paint. Furthermore, during the manufacturing process substantial and often costly environmental issues have to be addressed in order to manufacture the compositions in an environmentally safe manner not exposing either the environment or personnel working in the manufacture of such paint to hazardous conditions stemming from the ingredients in the paints and in particular the very volatile solvents used in traditional paints.