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Method for reclaiming solvent in poly(p-phenytene terephthalamide)resin production

A technology of poly-p-phenylene terephthalamide and p-phenylene phthalamide, which is applied in the field of solvent recovery, can solve problems such as difficult recovery of solvents, equipment corrosion, and easy volatilization, and meet the needs of equipment and production environments. Low requirements, low environmental pollution and high recovery rate

Active Publication Date: 2011-08-31
SINOCHEM HIGH PERFORMANCE FIBER MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the prior art, in order to recover the solvent, the direct distillation process and the extraction process are mainly used, wherein the former directly performs rectification operation on the washing liquid containing the solvent, the solvent is not easy to recover, the energy consumption is large, and the recovered solvent is not conducive to repeated use. The stability of production and the guarantee of product quality; while the latter has high requirements on the operating environment and explosion-proof of electrical equipment, serious corrosion of equipment, high energy consumption, and most of the introduced secondary solvents are highly toxic and volatile, which aggravates the impact on the environment. pollution

Method used

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Embodiment Construction

[0017] The present invention will be described in further detail below in conjunction with specific examples, but is not limited to the examples.

[0018] A method for reclaiming solvent from the washing liquid produced by PPTA resin, wherein the solvent is N-methylpyrrolidone, and the washing liquid is composed of water, sodium chloride, calcium chloride, N-methylpyrrolidone and a small amount of terephthalylene An oligomer of p-phenylenediamide. The method comprises the steps in turn:

[0019] (1), neutralize the washing solution of PPTA resin with NaOH solution, and then add a certain amount of sodium carbonate to make the calcium ion in the washing solution change to CaCO 3 Precipitate, separate by filtration, and collect the filtrate. The filtrate mainly contained water, NMP and NaCl. Filter cake is CaCO 3 and a small amount of oligomers of p-phenylene terephthalamide;

[0020] (2), pass the filtrate obtained in step (1) into the multi-effect evaporator in a counterc...

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Abstract

The invention relates to a method for reclaiming solvent in poly(p-phenytene terephthalamide) (PPTA) resin production. The method comprises the following steps: neutralizing cleaning solution for synthesizing PPTA resin by adopting basic solution; multi-effectively concentrating and dehydrating; crystallizing and separating; and stripping, decompressing and rectifying by two towers to prepare thesolvent with purity of over 99.8 percent. In a reclaiming process, the separated salt can be recycled through vacuum drying treatment. The method is stable and reliable, has high reclamation rate (over 96 percent), and has low requirement to equipment and production environment, thereby effectively reducing reclamation cost of the solvent and reducing environmental pollution.

Description

technical field [0001] The present invention relates to the recovery method of solvent in the production of poly-p-phenylene terephthalamide resin, specifically, the present invention relates to a kind of recovery N-alkyl substituted compound from the mixture of water, salt and N-alkyl substituted amide Amide method. Background technique [0002] Poly(p-phenylene terephthalamide) (PPTA) resin is the raw material for the preparation of high-strength, high-modulus, high-temperature-resistant special fiber para-aramid and aramid pulp with high friction resistance and high dispersibility. It can be used to produce para-aramid fibers with a specific strength 5-6 times that of steel wire, a specific modulus 2-3 times that of steel wire, and a high temperature resistance of 350 ° C, as well as aramid pulp, which is an ideal substitute for asbestos. Insulating paper with high temperature resistance and friction resistance is widely used in aerospace, transportation and communicatio...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J11/02C08L77/10
Inventor 张浩曹煜彤周助胜刘兆峰
Owner SINOCHEM HIGH PERFORMANCE FIBER MATERIALS CO LTD