Estimation of the mechanism to suppress water degradation of 1K heat-curing epoxy adhesive with high durability 2020-01-0227
In recent years, structural adhesives have been used in automotive applications in order to improve the rigidity and impact resistance of joints, and the need for them is expected to expand in the future. However, it is known that the degradation factors of adhesives are heat, load, and water, which cause degradation and decrease in strength. In this study, we focused on water absorption degradation, which is considered to be the largest degradation factor of adhesives, and succeeded in imparting high water resistance by adding an appropriate material to 1K heat-curing epoxy adhesives. This adhesive was subjected to a degradation acceleration test at 70℃100%RH 14days, and it was confirmed that hydrolysis did not occur, and the strength retention rate and cohesive failure rate were 100%. In this study, factors that give adhesive high durability were extracted, and the mechanism that these factors suppress water absorption degradation was estimated.