Curing agent, also known as hardener, is an important supporting material for determining the drying and curing of various two-component coatings. The molecular structure of the curing agent contains a reactive group capable of reacting with a reactive group in the molecular structure of the coating film-forming substance to crosslink the molecules of the film-forming substance to cure the coating into a film. For two-component curable coatings, if the curing agent is not added to the coating, the coating can be left for a long time without drying; and when the coating is mixed with an appropriate amount of curing agent, it can be thoroughly dried regardless of the thickness of the coating brush. . Different types of coatings use different curing agents. For example, a polyurethane coating should use a curing agent containing a hydroxyl group material; an epoxy resin coating should use an ethylenediamine or a polyamide curing agent; and an unsaturated polyester paint can use a styrene curing agent.