The invention relates to a preparation method of modified terminal-carboxyl-hyperbranched
polyamide resin. The method comprises the following steps of: uniformly mixing
diamine and ternary acid with the mole number of 1-2.0 times that of the
diamine, then heating to 70-90 DEG C, and adding terminal
epoxy group
silicone oil with the weight of 0.05-0.1 times that of the
diamine and dimethylbenzene with the weight of 0.02-0.1 times that of the diamine; heating for 1-3 hours at the temperature of 180-210 DEG C, warming to 220-240 DEG C, and heating for 1-3 hours; cooling to 90 DEG C, adding an
organic solvent with the weight of 1.0-1.5 times that of the diamine, an organic
silicon low
polymer with the weight of 1.5-2.0 times that of the diamine and a crosslinking catalyst with the weight of 1-5% that of the diamine; warming to 110-120 DEG C, and heating for 2-3 hours; and cooling to 90 DEG C, and finally adding the
organic solvent to adjust
solid content to 60-70%, so that the modified terminal-carboxyl-hyperbranched
polyamide resin is obtained. The resin prepared by adopting the preparation method provided by the invention can be used for preparing high temperature resistant low-surface-energy paint. According to the preparation method provided by the invention, when the terminal-carboxyl-hyperbranched
polyamide resin is synthesized, the terminal
epoxy group
silicon oil is added, so as to improve the heat-resisting performance and flexibility of polyamide; and crosslinking reaction is carried out on the organic
silicon low
polymer and the polyamide, so as to improve the heat-resisting performance of the polyamide.