KR100749968B1 - Wholly aromatic polyamide filament and its preparation method - Google Patents

Abstract

The present invention relates to a wholly aromatic polyamide filament and a method for producing the same, wherein a plurality of fins (3a) are rotated by a motor (2) in the reactor (20) for polymerization in producing the wholly aromatic polyamide polymer. A stirring device composed of a rotating body 3 having a rotating body 3 and a fixed body 4 having a plurality of pins 4a is installed to stir the aromatic diamine, aromatic dieside chloride and polymerization solvents introduced into the polymerization reactor 20. The rotational speed of the rotor 3 is controlled 10 to 100 times faster than the injection speed of the aromatic dieside chloride injected into the polymerization reactor 20 and the injection speed of the polymerization solvent in which the aromatic diamine is dissolved. It is characterized in that the contact frequency (Contact frequency) of the pin in the rotating body (3a) and the pin in the fixed body (4a) to 100 ~ 1,000㎐.

In the present invention, since the monomers are well mixed and reacted with each other in the polymerization reactor 20, the polymerization reaction proceeds uniformly in all regions within the polymerization reactor 20, thereby reducing the variation in the degree of polymerization of the polymer. For this reason, the wholly aromatic polyamide filament produced by the present invention has a narrow molecular weight distribution (PDI), and reduces defects of the crystal itself, thereby exhibiting properties such as improved strength and elastic modulus.

Wholly aromatic polyamides, filaments, polymers, fixtures, rotors, degree of polymerization deviations.

Description

Aromatic polyamide filament and method of manufacturing the same

1 is a process schematic diagram of making a wholly aromatic polyamide filament in a wet-wet spinning manner.

2 is a schematic cross-sectional view of a polymerization reactor 20 used in the present invention.

** Description of the symbols for the main parts of the drawings

2: Motor 3: Rotor 3a: Pin in Rotor

4: Fixture 4a: Pin in Fixture 10: Mesh

20 reactor for polymerization 21 monomer and polymerization solvent supply port

22 polymer outlet 30 spinning stock solution reservoir

40: spinneret 50: coagulation bath

60: washing device 70: drying device

80: heat treatment apparatus 90: winder

The present invention relates to a wholly aromatic polyamide filament and a method for producing the same, and more particularly to a method for producing a wholly aromatic polyamide filament having high strength and high elastic properties.

The wholly aromatic polyamide filament is a wholly aromatic by polymerizing aromatic diamine and aromatic dieside chloride in a polymerization solvent containing N-methyl-2-pyrrolidone, as disclosed in US Pat. Nos. 3,869,429 and 3,869,430. Preparing a polyamide polymer; dissolving the polymer in a concentrated sulfuric acid solvent to produce a spinning stock solution; spinning the spinning stock solution from a spinneret and passing the spun spinning material through a non-coagulating fluid layer into a coagulating bath. And filaments are formed, and the filaments are washed with water, dried and heat treated.

1 is a process schematic diagram of making a wholly aromatic polyamide filament in a conventional wet and dry spinning manner.

In the conventional method, when preparing the wholly aromatic polyamide polymer, the polymerization monomers introduced into the polymerization reactor 20 do not mix well with each other and do not polymerize uniformly over all regions of the reactor 20. There was.

Therefore, in the conventional method, the degree of polymerization degree of the wholly aromatic polyamide polymer is greatly generated, resulting in a decrease in strength and elastic modulus of the wholly aromatic polyamide filament.

The present invention is to produce a wholly aromatic polyamide filament with improved strength and elastic modulus while solving such a conventional problem.

The present invention is to improve the strength and elastic modulus of the wholly aromatic polyamide filament as a final product by minimizing the variation in the degree of polymerization of the polymer by allowing the polymerization reaction of the polymerization monomers to proceed uniformly in all regions of the polymerization reactor 20 Shall be.

In addition, the present invention is said to minimize the degree of polymerization degree of the polymer, so that the molecular weight distribution of the filament (Poldispersity Index, hereinafter referred to as "PDI") is narrow, it is referred to as a "parameter parameter" (g _Ⅱ ") showing a defect of the crystal itself. It is a technical problem to provide a wholly aromatic polyamide filament having reduced) and consequently improved strength and modulus.

In order to solve the above technical problem, in the present invention, a wholly aromatic polyamide polymer prepared by polymerizing an aromatic diamine and an aromatic dieside chloride in a polymerization solvent containing N-methyl-2-pyrrolidone is dissolved in a concentrated sulfuric acid solvent. In preparing a stock solution and spinning the same to produce a wholly aromatic polyamide filament, a plurality of fins are rotated by a motor 2 in the polymerization reactor 20 during the production of the wholly aromatic polyamide polymer. Aromatic diamine, aromatic dieside chloride which is introduced into the polymerization reactor 20 by the installation of a stirring device composed of a rotor 3 having (3a) and a stationary body 4 having a plurality of fins 4a. While stirring the polymerization solvents, the rotational speed of the rotor 3 is injected into the reactor 20 for polymerization and the aromatic diamine chloride and the aromatic diamine It is characterized by adjusting the contact frequency of the pin 3a and the pin 4a in the rotating body to 100 ~ 1,000 Hz while controlling the injection rate of the dissolved polymerization solvent 10 to 100 times faster. .

Further, the wholly aromatic polyamide filament of the present invention is characterized in that the molecular weight distribution (PDI) is 1.5 to 2.3, and the paracrystalline parameter (g _II ) before heat treatment is 1.7 to 1.9%.

Hereinafter, with reference to the accompanying drawings, it will be described in detail.

First, in the present invention, an aromatic diamine and an aromatic dieside chloride are polymerized in a polymerization solvent containing N-methyl-2-pyrrolidone to prepare a wholly aromatic polyamide polymer.

The aromatic diamine is P-phenylenediamine and the like, and the aromatic dieside chloride is terephthaloyl chloride and the like.

The polymerization solvent is N-methyl-2-pyrrolidone or the like in which calcium chloride is dissolved.

The present invention, when manufacturing the wholly aromatic polyamide polymer as described above is rotated by the motor (2) in the reactor 20 for polymerization as shown in Figure 2 and having a plurality of pins (3a) (3) and [ii] stirring the aromatic diamine, the aromatic dieside chloride and the polymerization solvent introduced into the polymerization reactor 20 by installing a stirring device composed of the stationary body 4 having a plurality of fins 4a, and The rotational speed of the rotor 3 is controlled 10 to 100 times faster than the injection rate of the aromatic dieside chloride injected into the polymerization reactor 20 and the injection rate of the polymerization solvent in which the aromatic diamine is dissolved. (3a) and the contact frequency (Contact frequency) of the pin 4a in the fixture is characterized in that it is adjusted to 100 ~ 1,000㎐.

2 is a schematic cross-sectional view of the polymerization reactor 20 used in the present invention.

Specifically, in the polymerization reactor 20 used in the present invention, as shown in FIG. 2, the rotor 3 and the rotor having a plurality of pins 3a, which are rotated by the motor 2 and have a plurality of pins 3a. The stirring device which consists of the stationary body 4 (Stator) which has (4a) is provided.

In the present invention, the polymerization monomer and polymerization solvent introduced into the polymerization reactor by the stirring device is polymerized while stirring.

At this time, the rotational speed of the rotor 3 is adjusted 10 to 100 times faster than the injection speed of the polymerization monomer and the polymerization solvent injected into the polymerization reactor 20 and at the same time, the pin 3a and the pin in the fixed body ( Adjust the contact frequency of 4a) to 100 ~ 1,000 ㎐.

When the rotational speed of the rotor 3 is less than 10 times the injection speed of the polymerization monomer or the contact frequency between the rotor 3 and the stationary fin 4a is less than 100 kPa, the polymerization monomer in the polymerization reactor and The polymerization solvents are not sufficiently stirred so that a uniform polymerization reaction does not occur over the entire region.

In addition, when the rotation speed of the rotor 3 exceeds 100 times the injection speed of the polymerization monomer, or the contact frequency of the pin 3a in the rotor and the pin 4a in the fixture exceeds 1,000 kPa, the polymerization reactor. Too high shear rate is added in the polymer, resulting in uneven polymerization.

It is preferable for the intrinsic viscosity of the wholly aromatic polyamide polymer to be 5.0 or more for improving the strength and elastic modulus of the filament.

Polymerization conditions of the polymer are the same as the known polymerization conditions disclosed in US Pat. No. 3,869,429 and the like.

One example of preparing the polymer is a solution in which 1 mole of para-phenylenediamine is dissolved in N-methyl-2-pyrrolidone containing about 1 mole of calcium chloride and 1 mole of terephthaloyl chloride as shown in FIG. Into the reactor for polymerization 20, a stirring device is installed and stirred to prepare a gel polymer, which is ground, washed with water and dried to produce a fine powder polymer. At this time, the terephthaloyl chloride may be added into the reactor for polymerization 20 divided into two stages.

Next, the spinning solution is prepared by dissolving the wholly aromatic polyamide polymer prepared as described above in a concentrated sulfuric acid solvent, and then spinning the spinning solution through the spinneret 40 as shown in FIG. The spinning is passed through a non-coagulating fluid layer into the coagulating bath 50 to form a filament, followed by washing, drying and heat treating the formed filament to produce a wholly aromatic polyamide filament. 1 is a process schematic diagram of producing a wholly aromatic polyamide filament by wet spinning spinning spinning solution.

The concentration of concentrated sulfuric acid used in preparing the spinning stock solution is preferably 97% to 100%, and chlorosulfuric acid, fluorosulfuric acid, and the like may also be used.

At this time, when the concentration of sulfuric acid is less than 97%, the solubility of the polymer is reduced and the liquid crystalline expression of the anisotropic solution becomes difficult. Therefore, it is difficult to manufacture a spinning solution having a constant viscosity, which makes it difficult to control the process during spinning and to provide mechanical properties of the final fiber. Can be degraded.

On the other hand, if the concentration of the concentrated sulfuric acid exceeds 100%, gwari (過離) because in oleum containing SO _3, as well as undesirable phase handled becomes an SO ₃ over takes place is partly dissolved in the polymer spinning solution to the inadequate and In addition, even if the fiber is obtained by spinning, there may be a problem that the internal structure of the fiber is not dense, the appearance is not gloss, and the speed of sulfuric acid diffused into the coagulation solution is lowered, thereby lowering the mechanical properties of the fiber.

On the other hand, it is preferable for fibrous physical property that the density | concentration of the polymer in a spinning dope is 10-25 weight%.

However, the present invention does not specifically limit the concentration of concentrated sulfuric acid and the concentration of the polymer in the spinning stock solution.

The non-coagulating fluid layer may mainly be an air layer or an inert gas layer.

The length of the non-coagulating fluid layer, that is, the distance between the bottom surface of the spinneret 40 and the surface of the coagulating solution contained in the coagulating bath 50 is preferably 0.1 to 15 cm for improving the properties of the radioactive or filament.

The coagulant liquid in the coagulant bath 50 may overflow. As the coagulating solution, water, brine or an aqueous sulfuric acid solution having a concentration of 70% or less is used.

Next, the formed filaments are handmade, dried, and heat treated to produce an wholly aromatic polyamide. Spinning wind speed is 700 ~ 1500m / min.

The wholly aromatic polyamide of the present invention prepared by the above method has a small polymer molecular weight distribution (PDI) by minimizing the variation in the degree of polymerization of the polymer, and a low para-crystal parameter (g _II ) indicating defects of the crystal itself. It is 26g / d or more, the elasticity modulus before heat processing is 750g / d or more, and the elasticity modulus after heat processing is excellent at 950g / d or more.

Specifically, the wholly aromatic polyamide filament of the present invention has a molecular weight distribution (PDI) of 1.5 to 2.3, preferably 1.5 to 2.0, more preferably 1.5 to 1.7, and the paracrystalline parameter (g _II ) before heat treatment is 1.7 to 1.7. 1.9%. Also from 300 ℃ 2 chogan para determined parameters _(Ⅱ g) after the heat treatment under a tension of 2% is 1.3~1.6%.

If the molecular weight distribution (PDI) and the paracrystalline parameter (g _II ) exceeds the above range, the modulus of elasticity modulus is insignificant. If the molecular weight distribution (PDI) and the above range is less than the above range, the modulus of elasticity increases, but it corresponds to a region that is difficult to achieve in the present invention.

As described above, the wholly aromatic polyamide filament of the present invention minimizes the variation in the degree of polymerization of the polymer compared with the conventional wholly aromatic polyamide filament, so that the molecular weight distribution (PDI) is narrow and the paracrystalline parameter (g _II ) which shows the defect of the crystal itself is low. . As a result, the wholly aromatic polyamide of the present invention is greatly improved in strength and modulus.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples.

However, the present invention is not limited to the scope of protection by the following examples.

Example  One

An aromatic diamine solution was prepared by maintaining 1,000 kg of N-methyl-2-pyrrolidone at 80 ° C. and dissolving 80 kg of calcium chloride and 48.67 kg of para-phenylenediamine.

The aromatic diamine solution prepared as described above, para-phenylenediamine, and molten terephthaloyl chloride in an equimolar amount, as shown in FIG. 2, the rotor 3 having a plurality of fins 3a and the plurality of fins 4a. The poly (para-phenylene terephthalamide) polymer having an intrinsic viscosity of 7.0 was prepared by introducing into and stirring into the polymerization reactor 20 in which the stirring device composed of the fixed body 4 having the c) was installed.

At this time, the rotational speed of the rotor 3 was adjusted to 30 times the injection speed of the polymerization monomer, and the contact frequency of the pin 3a in the rotor and the pin 4a in the fixture was adjusted to 500 kPa.

Next, the prepared polymer was dissolved in 99% concentrated sulfuric acid to prepare an optically anisotropic radiation stock solution having a polymer content of 18% by weight.

Next, after spinning the spinning solution prepared as described above through the spinneret 40 as shown in Figure 1, the coagulated liquid bath containing the water, which is the coagulant liquid through the 7 mm air layer Passed into 50 to form a filament.

Next, water was washed by spraying water at 25 ° C. on the filament formed as described above, and then passing the resultant through a two-stage dry roller having a surface temperature of 150 ° C., followed by winding and then winding the poly (para). -Phenylene terephthalamide) filament was prepared.

Table 1 shows the results of measuring various physical properties of the prepared poly (para-phenylene terephthalamide) filament.

Example  2

The poly (para-phenylene terephthalamide) filament prepared in Example 1 was heat treated at 300 ° C. for 2 seconds under 2% tension to prepare a heat treated poly (para-phenylene terephthalamide) filament.

Table 1 shows the results of measuring various physical properties of the prepared poly (para-phenylene terephthalamide) filament.

Comparative Example  One

 Same as Example 1 except that the aromatic diamine solution (B) prepared in Example 1 and the molten terephthaloyl chloride were fed into a conventional polymerization reactor equipped with one screw instead of the stirring device shown in FIG. Poly (para-phenylene terephthalamide) filament was not prepared under the conditions.

Table 1 shows the results of measuring various physical properties of the prepared poly (para-phenylene terephthalamide) filament.

Comparative Example  2

The poly (para-phenylene terephthalamide) filament prepared in Comparative Example 1 was heat treated at 300 ° C. for 2 seconds under 2% tension to prepare a heat treated poly (para-phenylene terephthalamide) filament.

The results of measuring various physical properties of the prepared poly (para-phenylene terephthalamide) filament are shown in Table 1.

<Table 1> Filament Property Evaluation Results

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Molecular Weight Distribution (PDI) 1.6 1.5 2.7 2.6 Paracrystalline parameter (g _Ⅱ ) Before heat treatment 1.80% - 1.66% - After heat treatment at 300 ℃ for 2 seconds under 2% tension - 1.56% - 1.91% Strength (g / d) 27 26 22 21 Modulus of elasticity (g / d) 840 1,080 740 930

Various physical properties of the filament in the present invention were measured by the following method.

Strength (g / d)

Instron tester (Instron Engineering Corp, Canton, Mass) was used to measure the strength (g) when the sample yarn is broken by using a sample yarn having a length of 25cm and then divided by the denier of the sample yarn to obtain the strength. The said intensity | strength was made into the average value after testing 5 times. At this time, the tensile speed was 300 mm / min, the ultra-load was fineness × 1 / 30g.

Elastic modulus (g / d)

The stress-strain curve of the sample yarn is obtained under the above-described strength measurement conditions, and then calculated from the slope on the stress-strain curve.

Unique viscosity

A sample solution is prepared by dissolving 0.1250 g of a sample (polymer or filament) in 25.0 ml of 98% sulfuric acid. Next, the flow time of the sample solution was measured using a capillary viscometer (Cannon Fenske Viscometer: Type 300) in a 30 ° C. constant temperature water bath, and the flow time of the sample solution was then measured. ) Is divided by the flow time of the solvent (sulfuric acid solution) (the number of falling seconds) to determine the relative viscosity (ηrel).

Next, the intrinsic viscosity is calculated by dividing the relative viscosity ηrel by the concentration of the sample solution.

Molecular weight distribution ( PDI )

Measure using GPC (Gel Permeation Chromatography) as follows.

(i) Synthesis of Whole Aromatic Polyamide Polymer Derivatives

Into dimethyl sulfoxide, a wholly aromatic polyamide filament (sample) and potassium ter-butoxide were dissolved, and the sample was dissolved at room temperature and nitrogen atmosphere, and allyl bromide was added thereto. To synthesize a wholly aromatic polyamide polymer substituted with an aryl group (see Macromolecules 2000, 33, 4390).

(Ii) molecular weight distribution measurement

The synthesized wholly aromatic polyamide polymer was dissolved in CHCl ₃ using a Shodex GPC column of the Waters manual injector kit at a temperature of 35 ° C. and a flow rate of 10 ml / min. The molecular weight distribution is measured on a GPC with a Refraction Index detector.

· Paracrystal Parameter ( Paracrystalline prameter , g _Ⅱ )

HOSEMANN's unit-cell area is measured using a diffraction theory with a Rigaku X-ray diffractometer (hereinafter referred to as "XRD") in the following manner.

(Ⅰ) Sampling

After arranging the wholly aromatic polyamide filaments (samples) as neatly as possible, the thickness is about 1,000 to 2,000 deniers and the length is 2 to 3 cm to the sample holder.

(Ii) Measurement procedure

-Hang the prepared sample on the sample attachment and bring the β-position to 0 °. (Set the sample on the sample fixture in the axial direction of the filament.)

-After finishing warm-up, slowly raise the XRD device to the measurement condition of voltage (50㎸) and current (180㎃) to enter the measurement preparation stage.

-Measure the meridional pattern that can calculate the para decision parameter (g _Ⅱ ).

-The main measurement conditions are set as follows.

Goniometer, Continuous scan mode, Scan angle range: 10-40 °, Scan speed: 0.5 [Step / Scan time is the peak intensity is small, Sufficient beam exposure time for 2,000 CPS]

-Measure the 2θ position of the peak (002 plane) appearing between 10 and 15 ° in the scanning profile.

-With the measured profile, substitute the following HOSEMANN equation to derive the parade parameter.

In the above formula, δs diffraction peak (diffraction peak) is the degree of dispersion, L is the crystal size (Crystal size), d is the spacing of the lattice plane (m), m is the order of the diffraction peak (order).

In the present invention, since the polymerization of the monomers for polymerization proceeds uniformly in the polymerization reactor 20, the degree of polymerization degree of the polymer is minimized.

For this reason, the wholly aromatic polyamide filament produced by the present invention minimizes the degree of polymerization of the polymer, the molecular weight distribution is narrow, the defects of the crystal itself is reduced, the strength and elastic modulus is greatly improved.

Claims (4)

A wholly aromatic polyamide filament, characterized in that the molecular weight distribution (PDI) is 1.5 to 2.3 and the paracrystalline parameter (g _II ) before heat treatment is 1.7 to 1.9%. The wholly aromatic polyamide filament according to claim 1, wherein the molecular weight distribution (PDI) is 1.5 to 2.0. The wholly aromatic polyamide filament according to claim 1, wherein the molecular weight distribution (PDI) is 1.5 to 1.7. The wholly aromatic polyamide filament according to claim 1, wherein the paracrystalline parameter (g _II ) after heat treatment at 300 ° C. for 2 seconds under 2% tension is 1.3 to 1.6%.

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