This study presents a novel approach to analyze cure shrinkage stress of ultraviolet (UV) curable adhesives by incorporating curing reaction heat. The exothermic behavior during UV curing was measured using thermocouple temperature measurements under continuous UV irradiation. Results showed sharp temperature increases immediately after curing initiation, reaching peak temperatures around 0.1 degree of cure (gel point), followed by rapid cooling. The volumetric heat generation density was determined through inverse analysis to reproduce the experimental temperature profiles. Cure shrinkage stress calculations incorporating both reaction heat and cure-dependent shift factors revealed that stress decreases during the exothermic reaction phase, with higher peak temperatures leading to lower final curing stresses. This methodology enables prediction of thermal effects on curing stress behavior in precision bonding applications.
YAMAMOTO et al. (Wed,) studied this question.