## 3 Results and Discussion
### Aging Resistance Test of Water-Based Coating Film with Microcapsules  
Based on the previous experimental results, the coating film prepared by the coating technology with the two coats of primer, three coats of topcoat, and the microcapsules added to the primer has the best performance. In order to explore whether the coating film has the best self-repairing and aging resistance, the coating film containing microcapsules and the coating film without adding microcapsules were subjected to an aging resistance test and self-repairing experiment at the same time. Table 6 displays the color aberration change of paint film after high temperature aging. Table 7 displays the chromatic aberration change of paint film after ultraviolet aging. After aging at 120 \({}^{\circ}\)C, the chromatic aberration of the coating film with microcapsules increased to 2.2, and that without microcapsules increased to 3.5. After aging at 160 \({}^{\circ}\)C, the chromatic aberration of the coating film containing microcapsules increased to 13.1, and that without microcapsules increased to 17.1. After UV aging, the chromatic aberration of the coating film containing microcapsules increased to 4.2, and that without microcapsules increased to 6.2. It can be seen that the longer the aging time, the greater the chromatic aberration. The higher the aging temperature, the greater the change of chromatic aberration of coating film [35; 36]. Compared with the coating film without microcapsules, the chromatic aberration of the coating film containing microcapsules changed less. Because of the influence of high temperature in oven and ultraviolet light, the coating film with microcapsules will crack and repair microcracks, which can restrain the surface damage to a certain extent. The increase of chromatic aberration was also partly due to the certain change of the color value of wood under the action of the environment, and the microcapsule particles on its surface played a protective role, so that the color change of coating film was smaller than that without microcapsule [37]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & **Aging at 120 \({}^{\circ}\)C** & & **Aging at 160 \({}^{\circ}\)C** \\ \hline
**Aging** & **Coating Film with** & **Coating Film without** & **Coating Film with** & **Coating Film without** \\
**Time (h)** & **Micocapsule** & **Micocapsule** & **Micocapsule** & **Micocapsule** \\ \hline
0 & 0 & 0 & 0 & 0 \\
8 & 0.5 & 0.9 & 3.3 & 3.4 \\
16 & 1.4 & 1.9 & 4.8 & 4.9 \\
24 & 1.8 & 2.2 & 9.3 & 11.8 \\
32 & 1.9 & 2.9 & 11.5 & 14.9 \\
40 & 2.2 & 3.5 & 13.1 & 17.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Chromatic aberration of coating film under high temperature aging environment. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample Number** & **Hardness** & **Adhesion (grade)** & **Shock Resistance** & **Fracture** \\  & & & **(kg:cm)** & **Elongation (\%)** \\ \hline
0 & HB \(\pm\) 0 & 0 \(\pm\) 0 & 6.0 \(\pm\) 0.1 & 7.6 \(\pm\) 0.1 \\
1 & 2H \(\pm\) 0 & 0 \(\pm\) 0 & 10.0 \(\pm\) 0.2 & 13.9 \(\pm\) 0.3 \\
2 & 3H \(\pm\) 0 & 0 \(\pm\) 0 & 12.0 \(\pm\) 0.3 & 26.3 \(\pm\) 0.6 \\
3 & 2H \(\pm\) 0 & 0 \(\pm\) 0 & 11.0 \(\pm\) 0.2 & 24.4 \(\pm\) 0.6 \\
4 & 2H \(\pm\) 0 & 0 \(\pm\) 0 & 10.0 \(\pm\) 0.2 & 14.9 \(\pm\) 0.3 \\
5 & 2H \(\pm\) 0 & 1 \(\pm\) 0 & 10.0 \(\pm\) 0.2 & 15.6 \(\pm\) 0.3 \\
6 & 3H \(\pm\) 0 & 0 \(\pm\) 0 & 10.0 \(\pm\) 0.2 & 17.9 \(\pm\) 0.4 \\
7 & 3H \(\pm\) 0 & 1 \(\pm\) 0 & 10.0 \(\pm\) 0.2 & 26.5 \(\pm\) 0.6 \\
8 & 2H \(\pm\) 0 & 0 \(\pm\) 0 & 11.0 \(\pm\) 0.2 & 24.4 \(\pm\) 0.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Mechanical properties of coating films under different coating technologies. Table 8 shows the glossiness change of the paint film after high temperature aging. Table 9 shows the glossiness change of the paint film after ultraviolet aging. After aging at 120 \({}^{\circ}\)C, the glossiness of the coating film containing microcapsules declined by 0.9, and that of the coating film without microcapsules declined by 3.2.