Synthesis of polyamic acid resin

Abstract

The invention discloses a synthesis method of polyamide acid resin. Water is inlet into a jacket of a reaction kettle. As dianhydride is input, the water of 10 DEG C to 30 DEG C is inlet into the jacket continuously and is stirred. After the viscosity of the resin reaches 60,000 centipoises to 70,000 centipoises, the addition of dianhydride is ceased, but hot water of 45 DEG C to 55 DEG C is inlet into the jacket to control the temperature of resin system at 60 DEG C to 70 DEG C, and after a preset temperature is reached, temperature is preserved and stirring is carried out continuously for 2hours to 5 hours. The optimum proposal is that the temperature of the resin system is controlled at 65 DEG C to 70 DEG C and the temperature-preservation stirring time is 3 hours to 4 hours. In orderto prevent from degradation, after the addition of dianhydride is ceased, triphenyl phosphate, a stabilizer, is added, with the addition amount equaling to 0.1 percent to 0.5 percent of the total weight of the resin system. The synthesis method ensures sufficient plasticization of the resin within quite a short time, improves the homogeneity of the system and facilitates the processing of postprocess; and the synthesis method is simple and feasible and increases quite little cost of equipment. Membranes produced by the resin obtained through the synthesis method are unchanged in main performance indexes, even in thickness, consistent in color and smooth in surface.

Description

(1) Technical field [0001] The invention relates to the technical field of resin synthesis, in particular to a synthesis method of polyamic acid resin. (2) Background technology [0002] The traditional method of synthesizing polyamic acid resin is to use a jacketed reaction kettle, and the heat exchange medium water at 10°C to 30°C is passed into the jacket to cool the reaction kettle. This is because the reaction of forming polyamic acid is an exothermic reaction. , lowering the temperature of the reactor during the synthesis process can make the polyamic acid produced reach a high molecular weight and ensure that the final polyamic acid meets a certain viscosity requirement. When various raw materials are added into the reactor and the viscosity is tested to meet the requirements, the synthesis process is generally completed by continuing to stir for 4 to 6 hours. However, near the end point, the viscosity of the resin is relatively high, and the stirring effect is not g...

AI Technical Summary

Problems solved by technology

However, near the end point, the viscosity of the resin is relatively high, and the stirring effect is not good. At this time, the dianhydride material put in from the upper part is difficult to disperse in the whole system, resulting in a large difference between the viscosity of the upper layer resin and the lower layer resin in the reactor. The resin system Not uniform enough, prolonging the stirring time may improve the uniformity of the system, but it also causes the problem of low production efficiency

Uneven viscosity will affect the quality of salivation in the next process, resulting in uneven film thickness and color, uneven surface, and even visible streaks on the film surface.