Solvent-free UV-curable Adhesives for a Protective Film by Double Cross-linking

Products such as mobile and display are mostly shipped with a protective film in order to prevent the product from external impacts or scratches. If pressure-sensitive adhesives (PSAs) for a protective film are solvent- or thermos setting types, it may cause non-uniform adhesive force or remain residue on a surface as the PSA film is removed. In this research, we studied on UV-curable adhesive formulation with a high cohesive property made through formation of cross-linking by adding various cross-linkers and metal chelates and found a correlation between formulation and adhesive properties. It was confirmed that the PSA having double cross-linking structure exhibited low peel strength, high shear strength/holding time and was smoothly removable from a surface without residues. As a result of analysis of the UV curing behavior utilizing the rheometer, additionally, the adhesive formulation is quickly cured under UV irradiation, which is suitable for high-speed adhesive process.