# Development of Effective Infrared Reflective Coatings
## 3 Results and Discussions
### Reflection Behavior of Coatings  
The behavior of coatings (primer plus enamel) in the 335 to 2500 nm spectrum is demonstrated in Table 5 and in Figures 2 and 3. By using a black background, we wanted to demonstrate the influence of a primer coated with infrared absorptive (low total solar reflectance) characteristics; on the other hand, the white primer had good infrared reflective (high total solar reflective) characteristics, i.e., in this case, the warming of the solid surface was much less than that of the black primer.  
\begin{table}
\begin{tabular}{c c c c c c c|c c c} \hline \hline \multirow{3}{*}{
\begin{tabular}{c} **Short Name of** \\ **Coating** \\ \end{tabular} } & \multirow{3}{*}{**Substrate**} & \multicolumn{6}{c}{**Reflection Values Measured at Different Wavelengths [nm]**} \\ \cline{3-10}  & & & **335–380** & **400–540** & **480–600** & **590–720** & **700–1100** & **1000–1700** & **1700–2500** \\ \cline{3-10}  & & **1** & **2** & **3** & **4** & **5** & **6** & **7** \\ \hline \multirow{3}{*}{Traditional} & white & 0.061 & 0.085 & 0.082 & 0.075 & 0.067 & 0.062 & 0.062 \\  & black & 0.059 & 0.085 & 0.082 & 0.075 & 0.067 & 0.063 & 0.062 \\ \hline \multirow{3}{*}{L95/CR28} & white & 0.063 & 0.119 & 0.097 & 0.099 & 0.283 & 0.730 & 0.635 \\  & black & 0.063 & 0.115 & 0.095 & 0.097 & 0.258 & 0.438 & 0.324 \\ \hline \multirow{3}{*}{S84/CR28} & white & 0.067 & 0.2 & 0.137 & 0.175 & 0.810 & 0.813 & 0.564 \\  & black & 0.066 & 0.147 & 0.113 & 0.142 & 0.489 & 0.331 & 0.136 \\ \hline \multirow{3}{*}{TR RU/ZD} & white & 0.058 & 0.170 & 0.122 & 0.113 & 0.544 & 0.795 & 0.589 \\  & black & 0.060 & 0.147 & 0.111 & 0.103 & 0.401 & 0.395 & 0.169 \\ \hline \multirow{3}{*}{S84/CR28/Lacquer} & white & 0.070 & 0.192 & 0.134 & 0.180 & 0.809 & 0.795 & 0.553 \\  & black & 0.068 & 0.119 & 0.100 & 0.124 & 0.334 & 0.197 & 0.085 \\ \hline \multirow{3}{*}{PS/ZD} & white & 0.064 & 0.167 & 0.118 & 0.104 & 0.533 & 0.790 & 0.586 \\  & black & 0.060 & 0.134 & 0.103 & 0.090 & 0.318 & 0.281 & 0.112 \\ \hline \multirow{3}{*}{S84/A80} & white & 0.057 & 0.184 & 0.125 & 0.135 & 0.723 & 0.788 & 0.602 \\  & black & 0.056 & 0.120 & 0.096 & 0.100 & 0.332 & 0.311 & 0.223 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Reflection behavior of coatings applied either on white or on black primers, measured in the large wavelength range (UV: 335–380 nm; visible: 400–720 nm; near infrared: 700–2500 nm).  
Figure 2: Reflection behavior of different coatings applied on white primer measured in the wavelength range between 335 nm and 2500 nm (FR: coatings developed on white primer; La: Lacquer).  
The curves in Figure 3 prove that the best results for coatings developed on a black background were measured on those that contain transparent infrared pigments. These were followed by coatings that contained top infrared pigments. The worst result was measured on the coating with traditional pigment.  
On the basis of the results measured on white and black backgrounds (Figures 2 and 3), it is clear that coatings on white primer always show higher infrared reflectance in the infrared range than on black primer. The only exception is in coatings with traditional pigments, where there is no difference caused by the different color of the primers. In order to get a coating with desired total infrared reflective ability, the use of a white primer with a high total reflectance pigment is advisable.