Preparation method for meta-aromatic polyamide fiber

An aromatic polyamide and fiber technology, which is applied in the field of preparation of meta-aramid fibers, can solve problems such as affecting the mechanical properties of finished fibers, increasing fiber voids, and large fiber micropores.

Active Publication Date: 2010-12-22
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

One-step coagulation may lead to: too much solvent content in the coagulation bath will lead to incomplete coagulation of fibers, resulting in parallel filaments of primary fibers, affecting subsequent tensile properties or increasing the denier unevenness of finished fibers; When it is less, it will cause the solidification process to be too fast, resulting in increased voids and micropores inside the fiber, which will affect the mechanical properties of the finished fiber
Under the conditions of the first-level coagulation bath, although fibers with less internal voids can be obtained under a certain coagulation bath ratio, the micropores of the fibers at this time are relatively large and not dense enough, and it is easy to form a skin-core structure, which affects the fiber. performance

Method used

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  • Preparation method for meta-aromatic polyamide fiber
  • Preparation method for meta-aromatic polyamide fiber
  • Preparation method for meta-aromatic polyamide fiber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Dissolve 1 part by weight of refined m-phenylenediamine (MPD) in 8.7 parts by weight of freshly distilled dry DMAc, and add 1.7 parts by weight of refined isophthaloyl chloride (IPC) at -10°C The precondensation is carried out to form a prepolymer containing hydrogen chloride, and the remaining 0.18 parts by weight of IPC are polymerized, and the temperature of the reactor is controlled below 50° C. for 1 hour to obtain a colorless and transparent polymer. Next, neutralize, neutralize the Ca(OH) used 2 The parts by weight are 0.685. Finally obtain polymer-containing 18.1wt%, logarithmic reduced viscosity η inh 1.86, CaCl 2 A spinning dope with a content of 8.26 wt%. For defoaming, control the temperature at 60°C and the spinning dope is metered by a metering pump under a nitrogen pressure of 0.2-0.5 MPa, and then extruded through a spinneret with 300 holes with a diameter of 0.08 mm into a first-stage coagulation bath. The coagulation bath composition is H 2 O 40wt...

Embodiment 2

[0029] Dissolve 1 part by weight of refined m-phenylenediamine (MPD) in 8.7 parts by weight of freshly distilled dry NMP, and add 1.7 parts by weight of refined isophthaloyl chloride (IPC) at -10°C The precondensation is carried out to form a prepolymer containing hydrogen chloride, and the remaining 0.18 parts by weight of IPC are polymerized, and the temperature of the reactor is controlled below 50° C. for 1 hour to obtain a colorless and transparent polymer. Next, neutralize, neutralize the Ca(OH) used 2 The parts by weight are 0.685. Finally, the polymer containing 18.1%, the logarithmic reduced viscosity η inh 1.86, CaCl 2 A spinning dope with a content of 8.26%. For defoaming, control the temperature at 60°C and the spinning dope is metered by a metering pump under a nitrogen pressure of 0.2-0.5 MPa, and then extruded through a spinneret with 300 holes with a diameter of 0.08 mm into a first-stage coagulation bath. The coagulation bath composition is H 2 O20wt%, NM...

Embodiment 3

[0031]Dissolve 1 part by weight of refined m-phenylenediamine (MPD) in 10 parts by weight of freshly distilled dry DMAc, and add 1.7 parts by weight of refined isophthaloyl chloride (IPC) at -10°C Pre-condensation is carried out to form a prepolymer containing hydrogen chloride, and the remaining 0.18 parts by weight of IPC is polymerized, and the temperature of the reactor is controlled below 50° C. for 1 hour to obtain a colorless and transparent polymer. Next, neutralize, neutralize the Ca(OH) used 2 The parts by weight are 0.685. Finally, a polymer containing 15.8 is obtained, and the logarithmic reduced viscosity η inh 1.71, CaCl 2 Spinning dope with a content of 7.21. For defoaming, control the temperature at 60°C and the spinning dope is metered by a metering pump under a nitrogen pressure of 0.2-0.5 MPa, and then extruded through a spinneret with 300 holes with a diameter of 0.08 mm into a first-stage coagulation bath. The coagulation bath composition is H 2 O 30w...

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Abstract

The invention relates to a preparation method for meta-aromatic polyamide fiber, comprising the following steps: (1) enabling metaphenylene diamine and m-phthaloyl chloride to be subject to low-temperature solution polymerization in an amide solvent, and utilizing calcium hydroxide to neutralize hydrogen chloride generated in the polymerization process; (2) after filtering, defoaming and metering the obtained spinning serous fluid, spraying into a multistage coagulating bath through the spinning nozzle of a spinneret orifice with the diameter of 0.08 mm, carrying out solidification and shaping step by step, and finally completely solidifying the fiber; and (3) carrying out moist heat drawing, washing, drying, dry heat drawing and heat shaping on solidified as-formed fiber to obtain the needed meta-aromatic polyamide fiber. The invention improves the fiber tensile strength, and the prepared fiber have round, even and compact cross section and excellent mechanical property, thereby enabling the prepared fiber to have better application prospect.

Description

technical field [0001] The invention belongs to the field of fiber preparation by wet spinning, in particular to a method for preparing meta-aramid fibers. Background technique [0002] Meta-aramid fibers have excellent heat resistance and flame resistance, as well as excellent high-temperature electrical insulation, and have similar spinnability to cotton fibers, so they are widely used in high-temperature resistance and fire prevention, and Protective clothing, high temperature filter media and electrical insulation materials. [0003] The preparation method of existing meta-aramid fiber mainly contains two kinds: [0004] (1) Use m-phenylenediamine and isophthaloyl chloride in N, N-diformyl acetamide (DMAc) for low-temperature solution polymerization, and the hydrogen chloride generated by the reaction is neutralized by calcium hydroxide to obtain a polymer containing calcium chloride The spinning dope of m-phenylene isophthalamide has a calcium chloride content of abou...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/90D01D5/06D01D10/02D01D10/06
Inventor 陈蕾于俊荣诸静胡祖明
Owner DONGHUA UNIV
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