## 3 Results and Analysis  
### Results  
The results of the test conducted after the chemical treatment on the test samples for each mixing ratio are as follows. Both the adhesive strength (with CRC board surface) and the peel strength (between sheet joint) had the tendency to decrease as the reclaimed butyl rubber content increased, as summarized in Tables 10 and 11. The adhesive strength results shown in Table 10 confirmed that it is possible for the plain specimen to ensure performance up to a reclaimed butyl rubber ratio of 56% (#6) compared to the total rubber content. However, when exposed to hydrochloric acid (HCl) and sulfuric acid (H\({}_{2}\)SO\({}_{4}\)) environments, the plain specimen can ensure performance up to a reclaimed butyl rubber ratio of 44% (#5), but there are difficulties in ensuring quality assurance when the reclaimed butyl rubber content exceeds the limits.  
The peel strength results shown in Table 11 confirmed that it is possible for the plain specimen to ensure performance up to a reclaimed butyl rubber ratio of 67% (#7) compared to the total rubber content. However, the plain specimen can ensure performance up to a reclaimed butyl rubber ratio of 44% (#5) when exposed to hydrochloric acid (HCl), nitric acid (HNO\({}_{3}\)), and sulfuric acid (H\({}_{2}\)SO\({}_{4}\)) environments, except for sodium chloride (NaCl), but only up to a reclaimed butyl rubber ratio of 56% (#6) in an alkaline environment. However, it is difficult to ensure quality assurance when the reclaimed butyl rubber content exceeds the limits.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \multirow{2}{*}{**Item**} & \multicolumn{8}{c}{**Adhesion Performance (N/mm)**} \\ \cline{2-11}  & **\#1** & **\#2** & **\#3** & **\#4** & **\#5** & **\#6** & **\#7** & **\#8** & **\#9** & **\#10** \\ \hline Plain & 1.86 & 1.83 & 1.73 & 1.65 & 1.58 & 1.53  
The comparison of changes in adhesive strength and peel strength due to acid treatment also revealed that it is possible to ensure performance up to a reclaimed butyl rubber ratio of 44% (#5) or less under all treatment conditions (hydrochloric acid (HCl), nitric acid (HNO3), and sulfuric acid (H2 SO4)), except for nitric acid (HNO3), as shown in Figures 8-10. When compared to the plain specimen, the chemically treated specimens showed a decrease in the reclaimed butyl rubber content to ensure the adhesive strength from 56% (#6) to 44% (#5). In addition, the reclaimed butyl rubber content to ensure peel strength decreased significantly from 67% (#7) to 44% (#5).  
Figure 11 shows the test result of the alkali-treated specimen. It was found that it is possible to ensure adhesive strength at a reclaimed butyl rubber ratio of 67% (#7), which is the same condition as the plain specimen; the reclaimed butyl rubber content required to ensure peel strength was found to be 56% (#6), which is an increase from 44% (#5), the reclaimed butyl rubber content needed to ensure adhesion performance under acid treatment conditions. This suggests that the performance degradation of butyl rubber is relatively low in an alkaline environment. In addition, it was confirmed that it is possible for the sodium chloride (NaCl)-treated specimen shown in Figure 12 to ensure adhesion performance and peel strength at a reclaimed butyl rubber ratio of 67% (#7), which is the same condition as the plain specimen, and that the performance degradation of butyl rubber is relatively low in a sodium chloride environment.  
Figure 11: Adhesion performance test result of the alkali-treated sample.  
Figure 10: Adhesion performance test result of the H\({}_{2}\)SO\({}_{4}\)-treated sample.