The present invention relates to a preparation method of flame-retardant polyester fiber. The flame-retardant polyester fiber is prepared by melt blending spinning of flame-retardant polyester masterbatch and polyester chips. The flame-retardant polyester masterbatch is obtained by mixing modified ammonium polyphosphate flame retardant with polyester powder, feeding the mixture into a twin-screw extruder, and sequentially performing melt blending, extrusion and pelletization. The preparation method of the modified ammonium polyphosphate flame retardant comprises: uniformly dispersing ammonium polyphosphate, hydroxybenzaldehyde-containing compound, aniline and dicyandiamide in a mixed solution of ethanol and water, stirring and reacting at 65–75°C, performing vacuum distillation until 1/4–1/3 of the mixed solution of ethanol and water remains, and then sequentially drying, washing and drying the product to obtain the modified ammonium polyphosphate flame retardant. The modified ammonium polyphosphate flame retardant of the present invention has good compatibility with polyester fiber, and the flame-retardant polyester fiber has excellent flame retardancy with little damage to the mechanical properties of polyester fiber.
Country Code: CN
Application Number: CN202410985882.5
