Preparation method of cardanol-based high temperature-resistant epoxy resin curing agent

The invention relates to a preparation method of a cardanol-based high temperature-resistant epoxy resin curing agent. The preparation method comprises the steps of firstly weighing cardanol, a phenolic compound, paraformaldehyde and diamine or polyamine according to weight, adding the cardanol, the phenolic compound and the paraformaldehyde into a reaction container, adding a catalyst, heating at the temperature of 75-100 DEG C for 2-6h to obtain an intermediate, then cooling the intermediate to 60-68 DEG C, adding the diamine or the polyamine, adding the remaining paraformaldehyde at the temperature in a stirring state, then heating till the temperature achieves 65-95 DEG C, reacting for 4-8h, and dehydrating in a vacuum state to obtain the cardanol-based high temperature-resistant epoxy resin curing agent provided by the invention. The synthesized curing agent has the advantages of great surface hardness and Shore hardness, excellent gloss, good high temperature resistance and low-temperature fast curing. According to the preparation method disclosed by the invention, the epoxy resin curing agent with a wide range of curing temperature, high temperature resistance and excellent surface performance is obtained and is suitable for requirements of primer paint and finish paint.