Behavior and Adhesion Performance of Acrylic PSAs using Semi-IPN Structure and UV/UV Stepwise Curing

Pressure-sensitive adhesives (PSAs) and UV-curable acrylic systems are widely utilized. In particular, PSAs have currently attracted significant attention because of their utility and applicability for manufacturing re-useable modules for smart devices. In this study, adhesion properties, UV-curing behavior, viscoelastic properties, and gel fraction were investigated. The UV/UV step curing process was utilized to overcome limitations, such as re-work or gap filling. The difference in physical properties between primary curing and secondary curing was confirmed. In addition, by adjusting the content of the crosslinking agent, the experiment based on controlling the structure of the semi-interpenetrating polymer network was conducted. We determined that physical properties varied with the crosslinking agent content. The degree of crosslinking was high, whereas the crosslinking density was low for 0.1–0.3 phr. However, both the degree of crosslinking and the crosslinking density increased for 0.5–1 phr.