The invention discloses a method for producing
polyester sizing agent, which belongs to the technical field of
sizing agent manufacturing. The method produces the novel
polyester sizing agent according to a principle of esterification, ester exchange reaction and polycondensation. The production process comprises two steps: firstly, mixing bishydroxy
ethylene (BHET), 5-sulfoisophthalic acid (SIPA) monosodium salt and
diethylene glycol(DEG), which serve as reaction materials, and
zinc acetate (ZnAc2), which serves as a catalyst, according to a certain ratio, heating, stirring and reacting; and secondly, cooling the
reaction product, transferring the
reaction product to a reaction kettle containing
triphenyl phosphate (TPP) serving as a stabilizer and antimonous
oxide (Sb2O3) serving as a catalyst, continuing to heat and react, and cooling to obtain the novel
polyester sizing agent. The polyester sizing agent produced by the method has an obviously improved
adhesive force for yeans, the water
solubility of the sizing agent and the softness of the sizing film are higher, the
moisture rate and
thermal stability of the polyester sizing agent are improved, and the
breaking strength, elongation at break,
wear resistance, buckling resistance and the like of the sizing film are improved obviously.