Evaluation of soft adhesives containing dual-curable melamine-based compounds

Although pressure-sensitive adhesives can be used in a wide variety of applications, their durable temperature range is generally limited due to their weak cohesive power. In this study, melamine-based compounds bearing UV-curable N-methyl acrylate groups and thermal-curable N-methoxylmethyl groups were evaluated as dual-curable materials for PSAs. The photo-curing abilities of MAOs are slightly inferior to those of TMP(EO)TA due to their rigid melamine core, but they could be improved by substituting acrylate groups onto the melamine core. In photo shrinkage, MAOs are less shrunk than TMP(EO)TA because of their greater size. Following the dual curing process, the storage modulus of MAO-containing PSA was maintained at approximately 3E6 dyne/cm2, even at high temperature. In particular, MAOs are very tolerant to heat exposure and thus could afford highly cohesive cured materials with a sufficient thermal curing process.