Production process of polyisophthaloyl metaphenylene diamine polymer

Abstract

The invention discloses a production process of a polyisophthaloyl metaphenylene diamine polymer. The production process comprises a diamine dissolution step, a normal-temperature polymerization reaction step, a coarse control neutralization reaction step and a fine control neutralization reaction step. According to the production process, the neutralization reaction can be better controlled and especially the finishing of the neutralization reaction can be controlled in such a way that a polymer is neutralized by respectively adding different neutralizing agents in two steps, more than 80% of neutralization reaction is completed in the first coarse control neutralization reaction step and the rest of neutralization reaction is completed by using diethylamine, so that the polymer with excellent neutralization quality is obtained, and the subsequent filtering and processing difficulties of a colloid are reduced.

Description

technical field [0001] The invention relates to the technical field of production technology of polym-phenylene isophthalamide polymer, in particular to a production technology of poly m-phenylene isophthalamide polymer. Background technique [0002] In the prior art, the preparation method of polym-phenylene isophthalamide polymer comprises a polymerization step, simultaneously generates by-product hydrogen chloride, neutralization step, neutralizes hydrogen chloride in the step polymerization step with an alkaline earth metal compound, The reaction produces alkaline earth metal chlorides that can be dissolved in the reaction system, and the neutralization reaction is carried out in a twin-screw extruder, such as the Chinese invention patent No. "200610118482.6", "Preparation of polym-phenylene isophthalamide spinning solution As shown in the Chinese invention patent of the method ", the neutralization steps in the production process of polym-phenylene isophthalamide polyme...

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Problems solved by technology

[0002] In the prior art, the preparation method of polym-phenylene isophthalamide polymer comprises a polymerization step, simultaneously generates by-product hydrogen chloride, neutralization step, neutralizes hydrogen chloride in the step polymerization step with an alkaline earth metal compound, The reaction produces alkaline earth metal chlorides that can be dissolved in the reaction system, and the neutralization reaction is carried out in a twin-screw extruder, such as the Chinese invention patent No. "200610118482.6", "Preparation of polym-phenylene isophthalamide spinning solution As shown in the Chinese invention patent of the "method", the neutralization step in the production process of polym-phenylene isophthalamide polymer is completed by one neutralization reaction step, and in the neutralization reaction process, the neutralization The reaction is difficult to grasp and control in the control of the neutralization end point of the polymer colloid

Because if the pH value of neutralization is very low, it will affect the stability of the polymer. If the pH value is required to be around 7, because the closer to the end point, the more moderate the reaction, it is easy to cause slight alkaline earth in the neutralized polymer. The excess of metal oxides or hydroxides exists. Since this excess is a powder suspension and insoluble in the polymer colloid, it will inevitably cause difficulties in the subsequent filtration of the polymer colloid.

Due to the inability to accurately control the neutralization end point of the polymer colloid, more impurities such as powdery suspended solids remain in the polymer, which increases the difficulty of colloid filtration, increases the complexity and processing difficulty of the subsequent process, and also reduces the quality of the obtained polymer. worse, so there is a need to improve