An energy-saving and environment-friendly meta-aramid polymerization process

An energy-saving, environmentally friendly, polymerization process technology, applied in the direction of single-component synthetic polymer rayon, single-component polyamide rayon, textile and papermaking, etc., can solve the problem of large energy consumption and equipment corrosion, affecting the quality of DMAc, spinning The spinnability of the silk solution has a great influence on the problems such as reducing the economic burden and waste of resources, avoiding the large-scale production of HCl gas, and avoiding the high temperature decomposition of DMAc.

Active Publication Date: 2020-03-24
广东彩艳股份有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the solvent has a high boiling point and high energy consumption; and during dry spinning, the number of holes in the spinneret is large, the spacing is small, the stability is poor, the production efficiency is low, and the cost is high.
[0012] The disadvantage is that the salt content is high, the amount of washing is large, and the salt content remaining in the fiber affects the performance of the fiber; in addition, the temperature of the coagulation liquid is high, the energy consumption is large, the solvent in the coagulation liquid volatilizes a lot, the working environment is poor, and the recycling and environmental protection investment
The disadvantage of this method is that after the polymerization is completed, due to the presence of a large amount of ammonium chloride, the fluidity of the solution is very poor, and it is difficult to filter after neutralization, and the insoluble salts that have not been removed have a great impact on the spinnability of the spinning solution.
The first one is processed by hazardous waste (high cost), in which DMAc and polymers are not recycled, this method has caused serious economic burden and waste of resources
The second is to partially recover DMAc through vacuum drying. DMAc is easy to decompose at high temperature, producing acidic gas, which affects the quality of recovered DMAc. It also consumes a lot of energy and equipment corrosion, and the polymers in it are not recycled.

Method used

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  • An energy-saving and environment-friendly meta-aramid polymerization process
  • An energy-saving and environment-friendly meta-aramid polymerization process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] Embodiment 1 (comparative example)

[0052] Add 60 parts by weight of anhydrous DMAc to a jacketed reactor equipped with a stirring paddle and a thermometer, and record the liquid level in the reactor as a. Add 6.25 parts by weight of flaky or molten m-phenylenediamine under the protection of nitrogen, and stir to dissolve. Put -15°C ice-salt water into the jacket, cool the solution to -10-0°C, and gradually add 11.16 parts by weight of powdered or molten isophthaloyl chloride while stirring to carry out prepolymerization. Speed, temperature and flow of cooling water in the jacket, so that the reaction temperature is controlled within the range of 0-10°C. Continue to stir for 15-20 minutes after the addition of the above-mentioned acid chloride, and gradually introduce dry ammonia gas for pre-polymerization and neutralization. During the pre-polymerization and neutralization process, control the addition rate of ammonia gas to keep the temperature within the range of 0...

Embodiment 2

[0055] Add 60 parts by weight of anhydrous DMAc to a jacketed reactor equipped with a stirring paddle and a thermometer, and record the liquid level in the reactor as a. Under the protection of nitrogen, add 6.25 parts by weight of flaky or molten m-phenylenediamine, stir to dissolve, pass -15°C ice-salt water into the jacket, cool the solution to -10~0°C, and stir Gradually add 11.16 parts by weight of powdery or molten isophthaloyl chloride for prepolymerization, and control the reaction temperature within the range of 0-10°C by controlling the feeding rate, the temperature and the flow rate of cooling water in the jacket. Continue stirring for 15-20 minutes after the addition of the above-mentioned acid chlorides, and gradually introduce dry ammonia gas for prepolymerization and neutralization, and control the addition rate of ammonia gas to keep the temperature within the range of 0-10°C. Stir and neutralize until the pH value is 6.0, stop adding ammonia, and continue stir...

Embodiment 3

[0059] Add 60 parts by weight of anhydrous DMAc to a jacketed reactor equipped with a stirring paddle and a thermometer, and record the liquid level in the reactor as a. Add 6.25 parts by weight of flaky or molten m-phenylenediamine under the protection of nitrogen, and stir to dissolve. Put -15°C ice-brine into the jacket, cool the solution, and gradually add 11.16 parts by weight of powdered or molten isophthaloyl chloride while stirring for prepolymerization. By controlling the feeding speed, the cooling water in the jacket Adjust the temperature and flow rate of the prepolymerization reaction. Continue stirring for 15-20 minutes after the addition of the above-mentioned acid chlorides, and gradually feed dry ammonia gas for prepolymerization and neutralization. Control the rate of adding ammonia to keep the pre-polymerization neutralization temperature within the range of 0-10°C. Stir and neutralize until the pH value is 6.0, stop adding ammonia, and continue stirring fo...

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PUM

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Abstract

The invention discloses a new energy-saving environment-friendly technology for meta-amide polymerization. The technology comprises the following steps: by adopting dry liquid ammonia, neutralizing the product after pre-polymerizing m-phenylenediamine and m-phthaloyl chloride and then firstly filtering under airtight or inert gas shielding condition; dissolving the acquired filter residue by using a solvent and then secondarily filtering under airtight or inert gas shielding condition; and recycling the filtrate and using for polymerizing in the next period, wherein the m-phenylenediamine and m-phthaloyl chloride are pre-polymerized under the inert gas shielding condition. The new energy-saving environment-friendly technology has the advantages that the overall energy consumption of the technology is reduced, especially, the environmental pollution is reduced, the serious economical burden and resource waste caused by the DMAc and polymer which are not recycled in the prior art are reduced and the defects of large energy consumption and equipment corrosion and influence on the quality of the recycled DMAc caused by the acid gas generated by the DMAc which is locally recycled in the manner of vacuum drying and is easy to decompose under high temperature are overcome.

Description

technical field [0001] The invention relates to a polymerization method in the production process of polym-phenylene isophthalamide fiber, which belongs to the technical field of new materials. The product has excellent properties such as corrosion resistance, temperature resistance, electrical insulation, and radiation resistance, and is widely used in aviation, Aerospace, fire protection, chemical industry, electronics, textile, machinery and other industries. Background technique [0002] Meta-aramid is produced from m-phenylenediamine (MPD) and isophthaloyl chloride (ICl) in organic solvents (such as dimethylacetamide DMAc, dimethylformamide DMF, N-methylpyrrolidone NMP etc.) polycondensation. The reaction formula is as follows: [0003] [0004] The generated by-product hydrogen chloride has always been a difficult problem in the industrial production process of meta-aramid products. Because hydrogen chloride reduces the solubility of the solvent, the solution is ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G69/46C08G69/32C08G69/04D01F6/60
CPCC08G69/04C08G69/32C08G69/46D01F6/605
Inventor 刘庆备
Owner 广东彩艳股份有限公司
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