## 3 Results and Discussion
### Influence of Coating Processes on the Performances of Waterborne Coatings Containing Microcapsules  
#### 3.2.1 Influence of Coating Processes on Optical Performances of Waterborne Coatings  
with Microcapsules  
The influence of coating processes on chromatic aberration of waterborne coatings containing microcapsules is shown in Table 2. The difference between waterborne coatings prepared by different coating processes is not significant. However, on the whole, the  
Figure 1: SEM morphology of microcapsules: (**A**) without rice husk powder and (**B**) with rice husk powder. Figure 2: Infrared spectrum of microcapsules with and without rice husk powder. chromatic aberration of coatings is relatively minimum when microcapsules are added to the primer. When microcapsules are added into the finish, the chromatic aberration of the coating is slightly larger than that of the primer. Because microcapsules are particles, which affect the uniformity of the coating, the chromatic aberration of the paint film is enhanced. Table 3 and Figure 3 show the chromatic aberration analysis of orthogonal experiment. The greater the range, the more significant the influence of this factor. By comparing the range value, the influence of number of finish coatings on chromatic aberration of paint film is the most obvious, and the influence of number of primer coatings on chromatic aberration of paint film is the least. The influence of coating processes on the gloss of waterborne coatings containing microcapsules was gauged at the incident angle of \(20^{\circ}\), \(60^{\circ}\), and \(85^{\circ}\), respectively. According to the Table 4, the gloss of the coatings No. 5-8 is better than that of the coatings No. 1-4. It indicates that the gloss of the coating under the process of \"microcapsule added to the primer\" is higher than the gloss of the coating under the process of \"microcapsules added to the finish\". This is because the finish, which is on the upper layer, mainly determines the surface morphology of the coating. Under the process of \"microcapsule added to the finish\", the particle numbers in the finish are increased, and it will increase the surface roughness of the coating, strengthen the diffuse reflection of light, and reduce the gloss of the coating. Compared with the coatings No. 5-8, it is found that the coatings No. 6 and No. 8 have the high gloss. The coatings No. 6 and 8 have more than one primer application compared to samples No. 5 and 7. It is inferred that the increase in the number of primer applications can have leveled the distribution of microcapsules over the primer. Hence, it can obtain a higher gloss by applying finish on the flatter primer. Taken together, the coating gloss is high via the coating processes of three times of primer and microcapsule added into the primer. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Samples (\#)** & \(\mathbf{L_{1}}\) & \(\mathbf{a_{1}}\) & \(\mathbf{b_{1}}\) & \(\mathbf{L_{2}}\) & \(\mathbf{a_{2}}\) & \(\mathbf{b_{2}}\) & \(\mathbf{\Delta L}\) & \(\mathbf{\Delta a}\) & \(\mathbf{\Delta b}\) & \(\mathbf{\Delta E}\) \\ \hline
1 & 75.0 & 12.4 & 24.0 & 74.7 & 12.0 & 23.1 & \(-0.3\) & \(-0.4\) & \(-0.9\) & 1.0 \\
2 & 72.5 & 12.0 & 24.7 & 74.4 & 12.5 & 22.2 & 1.9 & 0.5 & \(-2.5\) & 3.2 \\
3 & 67.5 & 17.6 & 28.1 & 66.0 & 17.6 & 27.7 & \(-1.5\) & 0 & \(-0.4\) & 1.5 \\
4 & 68.2 & 16.0 & 25.8 & 67.7 & 15.3 & 24.6 & \(-0.5\) & \(-0.7\) & \(-1.2\) & 1.5 \\
5 & 69.3 & 15.6 & 29.1 & 68.8 & 15.2 & 28.1 & \(-0.5\) & \(-0.4\) & \(-1.0\) & 1.2 \\
6 & 67.2 & 15.0 & 28.2 & 67.8 & 15.3 & 28.8 & 0.6 & 0.3 & 0.6 & 0.9 \\
7 & 69.5 & 14.2 & 27.6 & 70.4 & 14.2 & 26.9 & 0.9 & 0 & \(-0.7\) & 1.1 \\
8 & 69.2 & 13.4 & 28.5 & 70.4 & 13.5 & 28.0 & 1.2 & 0.1 & \(-0.5\) & 1.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Influence of coating processes on chromatic aberration of waterborne coating containing microcapsules.