Functional additive for amino baking varnishes and preparation method thereof

The invention relates to an amino baking varnish, and particularly relates to a functional additive for amino baking varnishes and a preparation method thereof. The method comprises the following steps: 1) putting 100-150 parts of epoxy resin, 30-50 parts of a benzoic acid, 2-6 parts of an antioxidant, 5-10 parts of butyl glycol ethers and 0.2-0.4 parts of a catalyst into a reaction kettle, and heating the obtained mixture to 80-120 DEG C; and carrying out heat preservation on the obtained mixture until the acid value of the obtained mixture is less than 5mgKOH/g; 2) uniformly dropwise adding a mixture of 10-15 parts of phosphoric acid and 50-80 parts of n-butyl alcohol into the reaction kettle within 1.0h, and carrying out heat preservation on the obtained mixture until the acid value of the obtained mixture is less than 20mgKOH/g; and 3) cooling and adding 50-70 parts of n-butyl alcohol into the reaction kettle to dilute, and then filtering the obtained product so as to obtain the functional additive. The preparation method disclosed by the invention is simple, and prepared products are strong in applicability and good in quality.