A kind of preparation method of meta-aramid fiber spinning glue

Abstract

The invention discloses a preparation method of meta-aramid spinning glue, which belongs to the technical field of aramid fiber production; the preparation method of meta-aramid spinning glue adopts the principle of intermittent low-temperature polycondensation, and the preparation process Pioneering two-step polymerization, two-step neutralization segmented multi-channel filtration process, and the introduction of new organic solvents and neutralizers, by controlling the reaction temperature and adjusting the pH value, it overcomes the neutralization process of the existing process Unfavorable factors such as water affecting product quality, difficulty in controlling polymerization viscosity, and large loss of equipment and raw materials caused by difficult filtration will ultimately result in a product solution with higher quality and lower cost.

Description

technical field [0001] The invention relates to an organic polymerization process method, in particular to a method for preparing meta-aramid fiber spinning glue, and belongs to the technical field of aramid fiber production. Background technique [0002] In the disclosed production technology of m-aramid spinning glue, most of them use m-phenylenediamine (MPD) to add polar solvent, control the temperature of the reaction system at -10-10°C, and gradually add isophthaloyl dichloride (IPC) reaction until the reaction is completed, then adjust the pH value of the reaction solution to neutral, and then filter to obtain the spinning stock solution. It is difficult to stabilize the product quality by using such a one-step reaction method, and excessive addition of isophthaloyl chloride often occurs , resulting in more waste in a single batch; the hydrochloric acid produced in the polymerization process, the prior art is to use hydroxide as a neutralizing agent to neutralize, and ...

AI Technical Summary

Problems solved by technology

[0002] In the disclosed production technology of m-aramid spinning glue, most of them use m-phenylenediamine (MPD) to add polar solvent, control the temperature of the reaction system at -10-10°C, and gradually add isophthaloyl dichloride (IPC) reaction until the reaction is completed, then adjust the pH value of the reaction solution to neutral, and then filter to obtain the spinning stock solution. It is difficult to stabilize the product quality by using such a one-step reaction method, and excessive addition of isophthaloyl chloride often occurs , resulting in more waste in a single batch; the hydrochloric acid produced in the polymerization process, the prior art is to use hydroxide as a neutralizing agent to neutralize, and the reaction of hydrochloric acid and hydroxide will generate a large amount of water in the neutralization process, and the generated water It will also lead to the decomposition of isophthaloyl dichloride. It should be pointed out that isophthaloyl dichloride and m-phenylenediamine have high chemical activity and are easily invalidated by external influences. Due to the presence of water after neutralization, the The polymerization reaction cannot be carried out completely, and it may also cause the reaction solution to become dark and form cross-linking of the polymer, which makes the spinnability of the polymer solution worse and the performance of the product decreases

[0003] At the same time, in the process of using hydroxide to neutralize the hydrochloric acid produced by the polymerization reaction, a large amount of hydroxide precipitates, such as calcium hydroxide or magnesium hydroxide, will also be produced. The large amount of precipitates will make it difficult to control the polymerization viscosity, and form The diameter of the precipitated hydroxide atoms is large, and the traditional technical approach is used to filter once after the neutralization is completed. A large amount of precipitation makes the filtration of the polymer solution more difficult, and the service life and operation cycle of the filtration equipment are significantly shortened. On the one hand, it is not conducive to Production, on the other hand, in the process of frequent replacement of filter media and cleaning of filter equipment, a large amount of loss of polymer solution will be caused

[0004] The above unfavorable factors will cause a substantial increase in production costs