The liquid crystal (LC) displays with narrow bezel design require excellent physical properties such as high adhesion, low moisture permeability, and low LC contamination. Among the adhesive components, the heat curing agent is an important component in the adhesive and plays a key role in the adhesion between the epoxy resins. In this study, new UV/heat dual-curable adhesives involving a multi-functional heat-curing agent of branched polyethylenimine have been prepared and evaluated by adhesive strength, moisture permeability, and LC contamination measurements. It is shown that the proposed adhesives offer excellent adhesive properties for narrow-bezel applications.