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Preparation of low salt-containing aramid fiber 1313spinning solution and process for spinning fibre by wet method

A technology of wet spinning and fiber method, which is applied in the preparation of low-salt aramid 1313 spinning solution and its wet spinning fiber field, which can solve the problems of difficult control of equimolar ratio, difficult removal of reaction heat, and molecular weight difference and other problems, to achieve the effect of increasing the molecular weight, reducing the dosage, and reducing the content of hydrogen chloride

Active Publication Date: 2008-10-15
DONGHUA UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although this method can produce a spinning solution with low salt content, it will be difficult to filter when the molecular weight of the polymer is high
[0011] Moreover, solution polymerization basically adopts a discontinuous method, the heat of reaction is not easy to remove, and local overheating can easily lead to differences in molecular weight.
The continuous polymerization method disclosed in U.S. Patent 3287324 adopts the one-time feeding method of acid chloride, and the equimolar ratio is difficult to grasp

Method used

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  • Preparation of low salt-containing aramid fiber 1313spinning solution and process for spinning fibre by wet method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Example 1: Preparation of spinning solution

[0045] Dissolve 1 part of refined MPD in 10.92 parts of freshly distilled dry DMAC, add 1.7 parts of 60°C refined IPC at -10°C for pre-polycondensation to form a prepolymer containing hydrogen chloride, keep the temperature below 0°C After reacting for 20 minutes and the remaining 0.18 parts of molten IPC enter a twin-screw extruder with a diameter of 30 mm, a length-to-diameter ratio of 1:60 and a rotation speed of 200 rpm. Control the temperature of the twin-screw reactor below 50°C, and draw a vacuum through the vent, about 15 minutes to extrude the colorless and transparent polymer, and then proceed to neutralization, Ca(OH) 2 The amount is 0.4 parts. The final result is 16.1% containing polymer, η inh 2.01, relative to polymer CaCl 2 For the spinning solution with a content of 14.8%, the neutralized solution is subjected to pH adjustment, mixing, defoaming, filtering, and entering the next step of spinning.

Embodiment 2

[0046] Example 2: Preparation of spinning solution

[0047]Dissolve 1 part of refined MPD in 10.92 parts of freshly distilled dry DMAC, add 1.6 parts of molten refined IPC to a general reactor with a stirrer at -18°C for pre-condensation to produce hydrogen chloride The prepolymer is kept at a temperature lower than 0°C. After 22 minutes of reaction and the remaining 0.28 parts of molten IPC enters a twin-screw extruder with a diameter of 50mm, a length-to-diameter ratio of 1:50 and a rotation speed of 180rpm. The temperature of the twin-screw reactor is controlled below 55℃, and the vacuum is drawn through the exhaust port, and the colorless and transparent polymer is extruded in about 17 minutes. After the prepolymer containing hydrogen chloride is formed, the neutralization is carried out. Ca(OH ) 2 The amount is 0.25 parts. The final product contains 15.5% polymer, η inh 1.88, relative to polymer CaCl 2 For the spinning solution with a content of 10.1%, the neutralized solutio...

Embodiment 3

[0048] Example 3: Fiber preparation

[0049] The spinning dope prepared in Example 1 of the spinning solution is coagulated through a spinneret with a diameter of 0.07 mm in a coagulation bath at a temperature of 8°C (the coagulation solution contains 15-25% CaCl 2 And 25-40% of the polar amide solvent, namely DMAC or NMP aqueous solution), and stretched 1.8 times in hot water at 78℃. The stretched fiber is immersed in hot water at 98℃ for 6 minutes and then enters It is further stretched 2.1 times in a heat pipe at 286°C, and finally crimped, heat-set, and cut to obtain a finished fiber. The fiber strength is 3.5 cN / dtex and the elongation at break is 33%.

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Abstract

The invention relates to a method for spinning aramid fiber 1313 with low salt content by wet spinning. The method comprises the following steps of: prepolymerizing m-phenylenediamine (MPD) and part m-phthaloyl chloride (IPC); adding the preformed polymer and the rest m-phthaloyl chloride into a double-screw extruder to extrude the aramid fiber 1313 containing chlorine hydride; extruding spinning dope into a aqueous coagulation bath after neutralizing the chlorine hydride with calcium hydroxide; crimping and cutting coagulated tows into the required fiber length via hot water drawing, water rinsing, drying, dry-heat drawing and heat setting after being taken out of the coagulation bath to receive a finished fiber. The method is convenient and simple, can improve the molecular weight of products and the evenness of polycondensate, and reduce the salt content of the final spinning solution.

Description

Technical field [0001] The present invention belongs to the field, and particularly relates to. Background technique [0002] Aramid 1313 has excellent heat resistance and flame resistance, as well as excellent high-temperature electrical insulation properties, and is used to prepare fire-resistant flame-resistant materials and high-temperature insulating materials, such as fibers, paper, etc. [0003] The existing methods for preparing aramid 1313 are usually: [0004] (1) Interface aggregation [0005] M-phenylenediamine and isophthaloyl chloride are reacted in a poor solvent for aramid 1313, such as tetrahydrofuran, and then mixed with an aqueous solution containing an acid absorbent at high speed. After the reaction is completed, a powdered aramid 1313 is produced. Spinning is performed after being dissolved in an amide solvent, and a salt as a co-solvent is added as necessary during dissolution. [0006] This method is operated intermittently, and the polymer must be separat...

Claims

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Application Information

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IPC IPC(8): D01D1/02D01D5/06D02J1/22D01F6/60C08G69/28C08G69/32C08G69/46
Inventor 胡祖明陈蕾钟洲于俊荣刘兆峰潘婉莲诸静
Owner DONGHUA UNIV
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