Adhesive(=PSA, Pressure Sensitive Adhesive) can be adhered to the surface of other objects with a small pressure. It has cohesive force and elasticity and can be strongly or weakly adhered, and does not contaminate the adherend when peeled off. Adhesives remain permanently viscous at room temperature and are not activated by solvents or heat, but physical properties change only under specified conditions. Adhesives have been used in the automotive, electrical, architectural, printing and paper industries. Recently, it is widely used in electronic materials, mobile phone touch screen, medical field.