Hamed Forootan - Department of Organic Colorants, Institute for Color Science and Technology, Tehran, Iran
Kamaladin Gharanjig - Department of Organic Colorants, Institute for Color Science and Technology, Tehran, Iran
Ebrahim Ghasemi - Department of Inorganic Glaze and Pigments, Institute for Color Science and Technology, Tehran, Iran

Helicopters and other low altitude rotorcrafts are subjected to harsh environmental conditions such as vaporized salt, damaging UV rays, moisture, extreme temperature, and pollution compounded by substances like oil, fuel, exhausted fumes, and bird/insect contaminates. The smaller mounted blade rotates vertically or near-vertically at the end of the tail of the traditional single-rotor helicopter. Warming of blade surface causes reduction of lifetime of its coatings and furthermore the blade itself. One of the ways of protection of the blade is the application of IR reflectance coatings which is called cool coatings. With this type of coatings, the temperature of the surface of the blades will reduce when it is under exposure of sun light. Therefore, the life-extension of the blades will be increased. This coatings contain cool pigments that are divided intothree categories: Organic cool pigments, inorganic cool pigments, and hybrid cool pigments. This research deals with reporting the application of organic cool pigments in reflectance coatings. Organic cool pigments contain azo, perylene, anthraquinone and phthalocyanine create a wide range of colors from yellow to green and black. Due to the high reflectance of the perylene pigments in the IR region, they are one of the most important groups of organic cool pigments to be utilized in aviation industry. Table 1 shows an example of organic cool pigment based on perylene. After applying the cool coating contain perylene pigment over white and black surfaces, the IR reflections are good and acceptable.

Cool pigment, Helicopter, IR Reflectance Coating, Organic Pigment, Perylene.