One-step preparation method of para aramid fibrids

A technology for para-aramid fibers and fibrids, which is applied in the field of one-step preparation of para-aramid fibrids, can solve problems such as equipment corrosion, complicated solvent recovery, and harsh operating environment, so as to avoid corrosion problems and achieve precise fibers. The effect of high size and speed

Active Publication Date: 2012-07-11
YANTAI TAYHO ADVANCED MATERIALS CO LTD
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Chinese Patent Publication No. CN 1475514A is to completely dissolve aramid 1414 resin with a certain intrinsic viscosity in concentrated sulfuric acid to make a slurry, and directly precipitate aramid pulp under vigorous stirring in a coagulation bath. This method prepares para-aramid The fiber pulp process is relatively simple, but it still cannot solve the corrosion problem of concentrated sulfuric acid on equipment
[0006] EP0104410 uses the amide-inorganic salt-tertiary amine ternary polymerization solvent system as the polymerization solvent for polycondensation reaction, and prepares para-aramid pulp through the fiber-forming method, but uses pyridine in the polymerization process, which makes solvent recovery complicated. Poor operating environment

Method used

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  • One-step preparation method of para aramid fibrids
  • One-step preparation method of para aramid fibrids

Examples

Experimental program
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Effect test

Embodiment 1

[0025] Such as Figure 1 Shown, respectively take 100L N-methylpyrrolidone (NMP), 3kg CaCl 2 and 2kg AlCl 3 , configured as NMP-CaCl 2 -AlCl 3 Polymerization solvent, under the protection of nitrogen, add 3.400kg of p-phenylenediamine to fully dissolve, add 3.840kg of terephthaloyl chloride at 5°C for pre-condensation reaction, add 2.560kg of terephthaloyl chloride for polycondensation reaction after the pre-condensation reaction, and react When colloid is produced in the process, the stirring is stopped, and the heat preservation and aging are carried out. The aging is carried out at 60° C. for 3 hours in a nitrogen atmosphere, and the intrinsic viscosity after aging is 42. The cured colloidal solution and the para-aramid pulp suspension (the average length of the para-aramid pulp is 0.5mm) with a mass percentage concentration of 0.05% pass through two colloid inlets 1 and two sedimentation liquids respectively The feed port 2 enters the precipitator for precipitation. Th...

Embodiment 2

[0027] Take 120LNMP and 3.5kg CaCl respectively 2 and 4.5kg AlCl 3 , configured as NMP-CaCl 2 -AlCl 3 Polymerization solvent, add 2.380kg of p-phenylenediamine under the protection of nitrogen to fully dissolve, add 2.682kg of terephthaloyl chloride at 5°C for precondensation reaction, add 1.788kg of terephthaloyl chloride after the precondensation reaction for polycondensation reaction, and react When colloid is produced in the process, the stirring is stopped, and the heat preservation and aging are carried out. The aging is carried out at 70° C. for 2 hours in a nitrogen atmosphere, and the intrinsic viscosity after aging is 7.9. The cured colloid solution and the mass percent concentration are 0.08% para-aramid pulp suspension (the average length of the para-aramid pulp is 0.8mm) through two colloid inlets 1 and two sedimentation liquids. The feed port 2 enters the precipitator for precipitating. The precipitator rotates at 2500rpm. The mass ratio of para-aramid colloid...

Embodiment 3

[0029] Take 100LNMP and 5kg CaCl respectively 2 and 2kgAlCl 3 , configured as NMP-CaCl 2 -AlCl 3 Polymerization solvent, add 2.160kg of p-phenylenediamine under the protection of nitrogen to fully dissolve, add 2.436kg of terephthaloyl chloride at 5°C for precondensation reaction, add 1.624kg of terephthaloyl chloride for polycondensation reaction after the precondensation reaction, and react When colloid is produced during the process, the stirring is stopped, and the heat preservation and curing are carried out. The curing is carried out at 80°C for 1.5 hours in a nitrogen atmosphere, and the intrinsic viscosity after curing is 6.5. The cured colloid solution and the mass percentage concentration are 0.02% para-aramid pulp suspension (the average length of para-aramid pulp is 0.6mm) through two colloid inlets 1 and two sedimentation liquids. Feed port 2 enters the precipitator for precipitator, the rotational speed of precipitator is 2500rpm, the mass ratio of para-aramid...

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Abstract

The invention discloses a one-step preparation method of para-aramid fibrids, comprising the following steps: mixing NMP, CaCl2 and AlCl3 to prepare an NMP-CaCl2-AlCl3 solvent, adding p-phenylenediamine under the protection of nitrogen for dissolving, adding p-phthaloyl chloride at 5 DEG C for pre-polycondensation reaction, wherein the molar ratio of p-phenylenediamine to p-phthaloyl chloride is 1:0.6; after finishing the pre-polycondensation reaction, adding p-phenylenediamine with dramatically stirring for polycondensation reaction, wherein the molar ratio of the p-phenylenediamine added in the polycondensation reaction to the p-phenylenediamine added in the pre-polycondensation reaction os 1:0.4; stopping stirring when colloid generates in the reaction, and curing in the presence of nitrogen at 50-80 DEG C; letting the cured colloid solution and a para aramid pulp suspension respectively enter a precipitation device with a rotating speed of 1000-3000 rpm through a feeding inlet for precipitation, after the precipitation, washing with water, pulping, dehydrating and drying to obtain the para aramid fibrids. The invention has the advantages of easy preparation of the para aramid fibrids, precise control of precipitation speed and fiber size of the fibrids, and prevention of fibers from bonding into blocks.

Description

technical field [0001] The invention relates to a method for preparing para-aramid precipitated fibers in one step. Background technique [0002] PPTA pulp (PPTA-pulp) is a differentiated variety of PPTA fiber newly developed in the past two decades. It is a high-temperature resistant and highly dispersible fibrillated PPTA fiber product. At the same time, it has a stronger composite effect, so as an ideal substitute for asbestos, it is widely used in the fields of friction, sealing, and reinforcing materials. [0003] At present, the preparation technologies of aramid pulp mainly include concentrated sulfuric acid liquid crystal spinning and cutting method of PPTA and low temperature solution polycondensation method. The spinning and cutting process is mature, and the pulp produced has stable properties. However, concentrated sulfuric acid severely corrodes the equipment, the processing technology is complicated, and the strength of the PPTA filament is extremely high, wh...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F8/12C08G69/32
Inventor 邱召明马千里侯春蕾
Owner YANTAI TAYHO ADVANCED MATERIALS CO LTD
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