Provided is a coating layer including a reaction product of a diisocyanate compound (a) selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, a polyol (b), and a copolymer (c) having a functional group selected from the group consisting of carboxylic acid groups, carboxylic acid ester groups, and carboxylic acid anhydride groups. The coating layer exhibits sufficient lubricity in wet conditions and has excellent durability.
