UV-induced tack-loss adhesive without residual glue prepared by isocyanate small molecule and acrylate prepolymer containing photoinitiator

In the semiconductor precision device processing and wafer cutting industry, products are typically etched or sliced to meet specific requirements. During this process, a novel type of adhesive is often utilized for bonding and securing purposes. After processing, some methods, such as light exposure and thermal application, can be used to make the adhesive lose its adhesiveness, so as to facilitate the peeling of the product without damaging the product. In this work, acrylate prepolymers containing photopolymerization groups were synthesized from 4-acryloyloxybenzophenone (4-ABP) and other acrylic monomers. UV-induced tack-loss of the acrylate pressure-sensitive adhesive (PSA) was achieved by blending the acrylic prepolymer with a small molecule isocyanate compound in an appropriate ratio and then coating for heat curing. It was observed that the incorporation of multifunctional isocyanate small molecule groups can enhance the overall performance of the tape. An addition amount of 0.6 wt% hexamethylene diisocyanate (HDI) was found to be more suitable than isophorone diisocyanate (IPDI), as it maintained good bonding performance and resulted in less residual glue. The increase in 4-ABP initially led to an improvement in bonding performance of the pressure sensitive adhesive tape, followed by a decrease, with an optimal addition amount of 1.2 wt%. After UV curing, the 180° peel strength of the adhesive tape measured below 1.0 N/25 mm, exhibiting the most significant decrease in peel strength and minimal residual adhesive content. This characteristic categorized it as a UV-induced tack-loss easy peeling pressure-sensitive adhesive tape. These results contribute to the further research and development of UV-induced tack-loss PSA.