Surface coating agent and surface coating method for elastic molding die.

摘要

A surface coating agent to be coated on the surface of an elastic molding die, which is a solvent solution of a polyurethane obtained by reacting a polyol with an aromatic polyisocyanate. The surface coating agent can be coated on the inside surface of the elastic molding die to form a coating layer, thereby obtaining a molding with surface gloss. Further, the surface coating agent can be incorporated with silicone and/or a fluorine compound to improve oil resistance of the elastic molding die, preventing the elastic molding die from being swollen by oil components of a molding material and improving durability. When a polyether type polyol is used as the polyol, water resistance of the elastic molding die can be even further improved. The surface coating agent using polycarbonatepolyol as the polyol has improved adhesion to the elastic molding die, thereby improving the durability. Further, the surface coating layer can be even more securely bonded to the surface of the elastic molding die by coating the surface coating agent after primer coating, or after acid treatment, or after acid treatment and primer coating.