KR20090124270A - Method for manufacturing wholly aromatic polyamide polymer and method for manufacturing aramide fiber using the same - Google Patents

Abstract

PURPOSE: A method for manufacturing wholly aromatic polyamide polymer is provided to prepare a wholly aromatic polyamide polymer with low inherent viscosity deviation, high inherent viscosity and uniform molecular weight. CONSTITUTION: A method for manufacturing wholly aromatic polyamide polymer comprises the steps of: preparing a mixed solution by dissolving aromatic diamine in a polymerization solvent; preparing a prepolymer by adding aromatic diacid halide to the mixed solution; and preparing a final polymer by adding further aromatic diacid halide to the prepolymer. The prepolymer has a molar ratio of aromatic diamine to aromatic family diacid halide is 1.20-2.00.

Description

Method for manufacturing WHO Aromatic Polyamide Polymer and Method for Manufacturing Aramide Fiber using The Same

The present invention relates to a method for producing a wholly aromatic polyamide polymer and a method for producing aramid fibers using the same, more specifically, a method for producing a wholly aromatic polyamide polymer having a high intrinsic viscosity with a small variation in intrinsic viscosity and using the same A method for producing aramid fibers.

Generally, wholly aromatic polyamide fibers, collectively referred to as aramid fibers, include para-aramid fibers and meta-aramid fibers having a structure in which the benzene rings are connected linearly through an amide group (CONH). Para-aramid fiber has excellent properties such as high strength, high elasticity, and low shrinkage. It is a thin thread of about 5mm thick and has a strong strength enough to lift 2 tons of cars. It is used in various industries in the high-tech industry. In addition, aramid fibers are carbonized at 500 ° C or higher, and thus are attracting attention in fields requiring high heat resistance.

Aramid fiber is a process for producing a wholly aromatic polyamide polymer by polymerizing an aromatic diamine and an aromatic dieside halide in a polymerization solvent containing N-methyl-2-pyrrolidone, dissolving this polymer in a concentrated sulfuric acid solvent to prepare a spinning dope After the step of spinning the spinning dope through the spinneret to pass through the non-coagulant fluid and coagulation bath sequentially to produce a filament, and the step of washing the filament, and drying and heat treatment .

The aramid fibers thus prepared are required to have high strength and high modulus of elasticity. To this end, the production of a wholly aromatic polyamide polymer having a high intrinsic viscosity has to be ensured, but to date, a wholly aromatic polyamide polymer having a satisfactory level of high intrinsic viscosity is required. The production method of is not known.

Moreover, the polyamide polymer produced by the conventional method has a problem that it is difficult to produce aramid fibers having a uniform characteristic because the variation in intrinsic viscosity is large.

The present invention was derived to solve the above problems, and an object of the present invention is to provide a method for producing a wholly aromatic polyamide polymer having a high intrinsic viscosity while having a low intrinsic viscosity variation.

Another object of the present invention is to provide a method for producing aramid fibers having high strength and high elastic modulus by using a wholly aromatic polyamide polymer having a high intrinsic viscosity while having a small variation in intrinsic viscosity.

As one aspect of the present invention for achieving the above object, the method for producing a wholly aromatic polyamide polymer of the present invention, the step of dissolving aromatic diamine in a polymerization solvent to prepare a mixed solution; Preparing a prepolymer by adding an aromatic dieside halide to the mixed solution; And adding the aromatic dieside halide to the prepolymer further to prepare a final polymer, wherein the prepolymer is characterized in that the molar ratio of aromatic diamine to aromatic dieside halide is 1.20 to 2.00.

As another aspect of the present invention for achieving the above object, the aramid fiber manufacturing method of the present invention, the step of dissolving the aromatic diamine in the polymerization solvent to prepare a mixed solution; Preparing a prepolymer by adding an aromatic dieside halide to the mixed solution, wherein the prepolymer has a molar ratio of aromatic diamine to aromatic dieside halide of from 1.20 to 2.00; Preparing a final polymer by further adding aromatic dieside halides to the prepolymer; Preparing a spin dope using the final polymer; And spinning the spinning dope.

According to the manufacturing method of the wholly aromatic polyamide polymer and the method for producing the aramid fiber using the same according to the present invention, in the production of the wholly aromatic polyamide polymer, a prepolymer is formed by first forming a final polymer and then preparing a final polymer By controlling the process so that the molar ratio of the aromatic diamine to the aromatic dieside halide of 1.20 to 2.00, it is possible to prepare a wholly aromatic polyamide polymer having a high intrinsic viscosity and a uniform molecular weight with little inherent viscosity variation, By producing the aramid fibers, aramid fibers of high strength and high elastic modulus can be obtained.

Hereinafter, an embodiment of a method for preparing the wholly aromatic polyamide polymer of the present invention and a method for producing aramid fibers using the same will be described in detail.

First, an inorganic salt is added to an organic solvent to prepare a polymerization solvent.

As the organic solvent, an amide organic solvent, a urea organic solvent, or a mixed organic solvent thereof may be used. Specific examples thereof include N-methyl-2-pyrrolidone (NMP), N, and N'-dimethylacetate. Amide (DMAc), hexamethylphosphoramide (HMPA), N, N, N ', N'-tetramethyl urea (TMU), N, N-dimethylformamide (DMF) or mixtures thereof.

The inorganic salt is added to increase the degree of polymerization of the aromatic polyamide, and specific examples thereof include halogenated alkali metal salts or halogenated alkaline earth metal salts such as CaCl 2, LiCl, NaCl, KCl, LiBr and KBr, and these inorganic salts. Silver may be added alone or in the form of a mixture of two or more thereof. As the amount of the inorganic salt increases, the degree of polymerization of the aromatic polyamide increases, but when the inorganic salt is added in an excessive amount, there may be an inorganic salt that does not dissolve. Thus, the inorganic salt is 10% by weight or less based on the total amount of the polymerization solvent. It is preferable that it is the range of. Since the inorganic salt has poor solubility in organic solvents, the final polymerization solvent can be prepared by completely dissolving the inorganic salts by adding water and then removing the water through a dehydration process.

Next, an aromatic diamine is dissolved in the prepared polymerization solvent to prepare a mixed solution.

Specific examples of the aromatic diamine include para-phenylenediamine, 4,4'-diaminobiphenyl, 2,6-naphthalenediamine, 1,5-naphthalenediamine or 4,4'-diaminobenzanilide. However, it is not necessarily limited thereto.

Next, while stirring the mixed solution, a predetermined amount of aromatic dieside halide is added to the mixed solution and prepolymerized. Specific examples of the aromatic dieside halide include terephthaloyl dichloride, 4,4'-benzoyl dichloride, 2,6-naphthalenedicarboxylic acid dichloride or 1,5-naphthalenedicarboxylic acid dichloride, but are not necessarily It is not limited.

In the polymerization of the aromatic diamine and the aromatic dieside halide, the reaction proceeds at a high rate with exotherm. In this way, when the polymerization rate is high, there is a problem in that the degree of polymerization differs between the finally obtained polymers. More specifically, since the polymerization reaction does not proceed simultaneously in the entire mixed solution, the polymer that has first started the polymerization proceeds rapidly to form a long molecular chain, whereas the polymer that has started the polymerization first polymerizes first. There is no choice but to form shorter molecular chains than the polymer from which the reaction was initiated, and the higher the polymerization rate, the greater the difference. As such, when the degree of polymerization difference between the polymers finally obtained increases, physical property variations also increase, making it difficult to achieve desired characteristics. Therefore, it is preferable to minimize the difference in degree of polymerization between the polymers finally obtained by preforming a prepolymer having a molecular chain of a predetermined length through a prepolymerization step, and then performing a polymerization step.

On the other hand, in order to obtain a polyamide polymer having a high intrinsic viscosity with a small variation in intrinsic viscosity, the prepolymer is also small and has an average molecular weight, but the molecular weight is uniform, so that the preliminary polymer having a large molecular weight at the subsequent final polymerization is It is important not to interfere with the polymerization of the prepolymer. Therefore, it is desirable to prepare prepolymers having a small molecular weight, ie short molecular chains.

In more detail, when the prepolymer is prepared by adding the aromatic dieside halide (P2) to the aromatic diamine (P1), a prepolymer having various chemical formulas may be formed as shown in Table 1 below.

TABLE 1

Formula of Prepolymer Aromatic diamine: aromatic dieside halide (molar ratio) (P1) ₂ (P2) 2.00: 1 (P1) ₃ (P2) ₂ 1.50: 1 (P1) ₄ (P2) ₃ 1.33: 1 (P1) ₅ (P2) ₄ 1.25: 1 (P1) ₆ (P2) ₅ 1.20: 1 (P1) ₇ (P2) ₆ 1.17: 1 (P1) ₈ (P2) ₇ 1.14: 1 (P1) ₉ (P2) ₈ 1.13: 1 (P1) ₁₀ (P2) ₉ 1.11: 1 (P1) ₁₁ (P2) ₁₀ 1.10: 1 (P1) ₁₂ (P2) ₁₁ 1.09: 1 (P1) ₁₃ (P2) ₁₂ 1.08: 1 (P1) ₁₄ (P2) ₁₃ 1.08: 1 (P1) ₁₅ (P2) ₁₄ 1.07: 1 : :

According to the present invention, the molecular weight of the prepolymer can be controlled by measuring the average molar ratio of the aromatic diamine to the aromatic dieside halide in the prepolymer, and the average molar ratio of the aromatic amine to the aromatic dieside halide of the prepolymer is 1.20 to 2.00, More preferably, the process conditions of the prepolymerization are controlled to be 1.80 to 2.00. If the average molar ratio of aromatic diamine to aromatic dieside halide in the prepolymer is too small, for example, less than 1.20, it means that many prepolymers with long molecular chains, that is, high molecular weights, have been produced. Not only do not obtain a final polymer having, but also a large variation in intrinsic viscosity. Conversely, when the average molar ratio exceeds 2.00, a by-product is obtained as a prepolymer in which the aromatic diamines react with each other, and the reaction balance of the aromatic diamine and the aromatic dieside halide as a whole is broken, resulting in a low molecular weight final polymer or gelation to obtain a molecular weight. Can not be controlled.

More specifically, the molar ratio of aromatic diamine to aromatic dieside halide of the prepolymer is measured using NMR. If the measured molar ratio is out of the above range, the prepolymer is prepared again by changing at least one of the reaction temperature and reaction time applied during the preparation of the prepolymer or adjusting the amount of the aromatic dieside halide added in the prepolymerization process. Proper process conditions can be found by repeating the above steps until the mole ratio of aromatic diamine to aromatic dieside halide of the prepolymer indicates the above range.

For example, when the polymerization reaction occurs in the prepolymerization process so that a large molecular weight of the prepolymer having a large molecular weight is generated so that the average molar ratio of the aromatic diamine to the aromatic dieside halide is less than 1.2, the reaction temperature is controlled to suppress the polymerization reaction. It should be elevated. However, when the reaction temperature is set above a certain temperature, since the polymerization reaction is stopped in the P1-P2 structure, the average molar ratio of the aromatic diamine to the aromatic dieside halide is lowered again.

It is also possible to control the average molar ratio of aromatic diamine to aromatic dieside halides by increasing or decreasing the reaction time. In general, reducing the reaction time results in less polymerization reactions, which increases the average molar ratio of aromatic diamine to aromatic dieside halides. Reducing the reaction time above time leaves the prepolymer unreacted in the P1-P2 structure, resulting in a lower average molar ratio of aromatic diamine to aromatic dieside halide.

According to one embodiment of the invention, the prepolymerization process is carried out while maintaining the reaction temperature at 0 ~ 45 ℃ in the reactor, the reaction time gives a sufficient polymerization time of about 3 to 15 minutes, the wholly aromatic polyamide polymer It is preferable to add only 20 to 40% of the total amount of the aromatic dieside halide necessary for the preparation during the prepolymerization process.

On the other hand, to illustrate the method of measuring the average molar ratio of the aromatic diamine to the aromatic dieside halide of the prepolymer, i) about 10mg of the prepolymer sample in an NMR tube and vacuum dried at about 60 ℃ for 4 hours to remove moisture After removal, ii) add about 0.5 ml of D2SO4 to the tube and dissolve the sample at room temperature. iii) Subsequently, add 3 drops of TMS as reference material and measure 1 H-NMR at room temperature. iv) As a result, the area of the peak appearing at 7.5 ppm is calculated as the mole value of the aromatic diamine, and the area of the peak appearing at 7.9 ppm is calculated as the mole value of the aromatic dieside chloride, thereby obtaining an aromatic dieside halide of the prepolymer. The average molar ratio of aromatic diamine is obtained.

After the completion of the prepolymerization process, the temperature is lowered to 0 to 10 ° C. and an aromatic dieside halide is further added to the prepolymer to prepare a final polymer.

Since aromatic dieside halides react with aromatic diamines in a 1: 1 molar ratio when preparing the aromatic polyamide polymer, the amount of aromatic dieside halides added during the final polymerization is equal to the amount of moles equivalent to the aromatic diamines when added to the prepolymerization. mole). However, when preparing the polymerization solvent, a small amount of water added to assist in dissolving the inorganic salt may remain even after the dehydration process, in which case a small amount of water may react with the aromatic dieside halide to form an insoluble substance. . Therefore, in view of the formation of such an insoluble substance, a small amount of aromatic dieside halide may be added more than aromatic diamine.

After completing the polymerization process, it is preferable to adjust the amount of aromatic diamine and dieside halide so that the concentration of the final polymer in the total polymerization solution is about 5 to 20% by weight. When the aromatic diamine and the dieside halide are added so that the concentration of the final polymer is less than 5% by weight, the polymerization rate is lowered and the reaction must be carried out for a long time, resulting in low economic efficiency, and the aromatic diamine so that the concentration of the polymer exceeds 20% by weight. This is because when the addition dieside halide is added, the polymerization reaction does not proceed smoothly and the intrinsic viscosity of the polymer cannot be improved to 5.5 or more.

Specific examples of the aromatic polyamide polymer obtained by the polymerization step include poly (paraphenylene terephthal-amide: PPD-T), poly (4,4'-benzanilide terephthalamide), poly (paraphenylene-4, 4'-biphenylene-dicarboxylic acid amide) or poly (paraphenylene-2,6-naphthalenedicarboxylic acid amide).

Subsequently, the acid produced during the polymerization reaction is neutralized with an alkali compound.

Since the aromatic polyamide polymer obtained through the polymerization is present in the form of an acid crumb such as bread crumb, the flowability of the aromatic polyamide solution is poor. Therefore, in order to improve the fluidity, it is preferable to proceed with the subsequent process in the state of making the slurry by adding water to the aromatic polyamide solution. On the other hand, when making an aromatic polyamide polymer slurry, the neutralization process can also be performed simultaneously by using water which melt | dissolved the alkali compound.

The inorganic alkali compound is an alkali metal of NaOH, Li2CO3, CaCO3, LiH, CaH2, LiOH, Ca (OH) 2, Li2O or CaO, carbonate of alkaline earth metal, hydride of alkaline earth metal, hydroxide of alkaline earth metal, or oxide of alkaline earth metal It is selected from the group consisting of.

When an inorganic alkali compound is added to an aromatic polyamide solution in a strong acid state containing a large amount of hydrochloric acid, the reaction rapidly reacts with hydrochloric acid, so that the neutralization proceeds rapidly. The reaction rate is drastically reduced and the inorganic alkali compound remains in the neutralization solution in an unreacted state. This causes a problem that the insoluble inorganic alkali compound must be filtered through a filter after the neutralization is completed. Therefore, in order to prevent the formation of insoluble foreign matter in the aromatic polyamide solution, the neutralization process can be carried out at several times.

Subsequently, the neutralization process is completed to grind the aromatic polyamide polymer in a crumb state in which the acid is removed.

If the particle size of the polymer is too large in the extraction process described later, the polymerization solvent extraction process takes a lot of time and the polymerization solvent extraction efficiency is lowered, so that the grinding process is performed to reduce the particle size of the polymer before the extraction process.

Next, the polymerization solvent is extracted from the pulverized aromatic polyamide polymer. Since the polymerization solvent used for the polymerization step is contained in the aromatic polyamide polymer obtained by the polymerization, such a polymerization solvent must be extracted from the polymer, and the extracted polymerization solvent can be reused in the polymerization step. This extraction process is most effective and economical to perform with water. The extraction process may be performed by installing a filter in a bath having a discharge port, placing a polymer in the form of a crumb on the filter, and then pouring water to discharge the polymerization solvent contained in the polymer together with water to the discharge port.

Next, the remaining water after the extraction step is dehydrated, and then the drying process is completed to complete the production of the aromatic polyamide polymer. Thereafter, a classification process may be performed to classify the aromatic polyamide polymers by size for the spinning process.

Spinning dope is prepared by dissolving the aromatic polyamide polymer prepared as above in a concentrated sulfuric acid solvent having a concentration of 97 to 103%. Instead of the concentrated sulfuric acid, chloro sulfuric acid, fluoro sulfuric acid and the like may also be used.

The polymer concentration in the spin dope is preferably 10 to 25% by weight for the fiber properties. As the polyamide polymer concentration increases, the intrinsic viscosity (IV) of the spinning dope also increases, but beyond the critical concentration point, the viscosity of the spinning dope rapidly decreases, where the spinning dope becomes a solid phase. It changes from optically isotropic to optically anisotropic without forming a phase. Since the anisotropic spin dope can be made of high strength aramid fibers due to its structural and functional properties without a separate drawing process, it is preferable that the concentration of the polyamide polymer in the spinning dope exceeds the above critical concentration, but the concentration is excessively high. If large, the viscosity of the spinning dope is excessively low.

After spinning the spin dope using a spinneret (spinneret) to form a filament by solidifying in a coagulation bath through an air gap (air gap).

The air gap may be mainly an air layer or an inert gas layer, the length of the air gap is 0.1 to 15 cm is preferable for improving the physical properties of the filament is produced.

The spinneret has a plurality of capillaries having a diameter of 0.1 mm or less. If the diameter of the capillary formed in the spinneret exceeds 0.1 mm, the molecular orientation of the resulting filament is poor, resulting in a decrease in the strength of the filament. The coagulation bath is located at the bottom of the spinneret and a coagulation solution is stored therein, and a coagulation tube is formed at the bottom of the coagulation bath. Accordingly, the radiant passing through the capillary of the spinneret is solidified while sequentially descending through the air gap and the coagulating liquid to form a filament, and the filament is discharged while passing through the coagulation tube below the coagulation bath. In addition to the filament, the coagulation solution is discharged through the coagulation tube, so that the coagulation solution must be continuously supplied to the coagulation bath as much as the discharge liquid.

In addition, the coagulation tube is formed with a jet device (jet device) can be injected to the filament passing through the coagulation tube. The injection device has a plurality of jet openings and injects the coagulating liquid toward the filaments from the plurality of injection openings. The plurality of injection holes are preferably arranged such that the coagulating solution can be sprayed in perfect symmetry with respect to the filament. The spray angle of the coagulating liquid is preferably 0 to 85 ° with respect to the axial direction of the filament, and in particular, a spray angle of 30 ° is suitable for a commercial production process.

The coagulating solution may be added sulfuric acid to water, ethylene glycol, glycerol, alcohol, or a mixture thereof, and is maintained at -10 to +90 ℃. When the radiation passed through the spinneret passes through the coagulating solution, the sulfuric acid in the emission is removed and filaments are formed. When sulfuric acid is rapidly removed from the surface, the surface is solidified before the sulfuric acid contained therein escapes. Since the problem of the uniformity of the filament may be lowered, sulfuric acid is added to the coagulating solution in order to prevent sulfuric acid from escaping rapidly from the surface of the radiant.

Next, sulfuric acid remaining in the obtained filament is removed.

Sulfuric acid used in the manufacture of the spinning dope can remain but is not completely removed, although most of the emissions are passed through the coagulation bath. Moreover, when sulfuric acid is added to the coagulation liquid of a coagulation tank in order to make sulfuric acid escape | emit uniformly from a effluent, there is a high possibility that sulfuric acid will remain in the filament obtained. Since the amount of sulfuric acid remaining in the filament may adversely affect the aramid fiber properties no matter how small the amount, it is very important to completely remove the sulfuric acid remaining in the filament.

Sulfuric acid remaining in the filament may be removed through a washing process using water or a mixed solution of water and an alkaline solution. The washing process may be carried out in a multi-step process, for example, primary washing with a sulfuric acid-containing filament with 0.3 to 1.3% of an aqueous caustic solution, followed by 0.01 to 0.1% of a thinner caustic solution You can do a second flush.

Subsequently, a drying process is performed to control the water content remaining in the filament.

The drying process may control the time for which the filament is in contact with the heated drying roll, or the moisture content of the filament by adjusting the temperature of the drying roll.

Meanwhile, a tension is applied to the filament during the spinning, washing, neutralizing, and drying process, and the optimum magnitude of the tension applied to the filament during the drying process is about 3.0 to 7.0 gpd although it is determined by the overall spinning condition. It is preferable to dry the filament under the tension of. If the tension during drying is less than 3.0 gpd, the molecular orientation is reduced and ultimately the strength of the fiber is lowered. On the contrary, when the tension in drying exceeds 7.0 gpd, there is a fear that the filament is cut, which causes manufacturing difficulties. On the other hand, the magnitude of the tension applied to the filament can be adjusted by appropriately controlling the surface speed of the roll for moving the filament.

The drying rolls are heated by some means, and the drying rolls are preferably at least partly surrounded by heat blocking means in order to prevent excessive heat from being released from the heated rolls and thereby causing heat loss.

Subsequently, the dried filament is wound on a branch pipe. Spinning speed is 300 to 1500 m / min.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the following examples are only intended to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

* Aromatic diesides of the prepolymer Determination of the average molar ratio of aromatic diamines to halides

i) Put about 10mg of the prepolymer sample in an NMR tube to remove moisture by vacuum drying at about 60 ° C for 4 hours, and ii) add about 0.5ml of D2SO4 to the tube and dissolve the sample at room temperature. iii) Subsequently, add 3 drops of TMS as reference material and measure 1 H-NMR at room temperature. iv) As a result, the area of the peak appearing at 7.5 ppm is calculated as the mole value of the aromatic diamine, and the area of the peak appearing at 7.9 ppm is calculated as the mole value of the aromatic dieside chloride, thereby obtaining an aromatic dieside halide of the prepolymer. The average molar ratio of aromatic diamine is obtained.

* All inherent viscosity of the aromatic polyamide polymer (Inherent Viscosity : IV) Measurement

Intrinsic viscosity (I.V.) is defined by the equation

I.V. = ln (ηrel) / C

Here, C is the concentration of the polymer solution (solution in which 0.5 g of the polymer is dissolved in 100 ml of concentrated sulfuric acid), and the relative viscosity ηrel is the flow time ratio between the polymer solution and the solvent measured by a capillary viscometer at 30 ° C. Unless stated otherwise, intrinsic viscosity values were determined using 95-98% concentrated sulfuric acid solvent.

Example  One

A mixed solution was prepared by dissolving 5.00 g of para-phenylenediamine in 100 ml of a polymerization solvent in which 7 wt% of CaCl 2 was added to N-methyl-2-pyrrolidone (NMP). 2.80 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 300 rpm for 3 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.20. 6.26 g of terephthaloyl dichloride was further added to the prepolymer thus prepared to prepare a final polymer, poly (paraphenyleneterephthal-amide: PPD-T).

Example  2

Except that a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride was 1.40 by adding 2.80 g of terephthaloyl dichloride to the mixed solution and reacting at a rotational force of 500 rpm for 6 minutes. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  3

Except that 3.55 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.45. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  4

Except that 2.99 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 300 rpm for 3 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.50. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  5

Except that 1.90 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 300 rpm for 3 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.60. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  6

Except that 2.99 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.80. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  7

Except that 3.18 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 300 rpm for 3 minutes, except that a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride was 1.87. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  8

Except that 3.36 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 300 rpm for 3 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.90. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  9

Except that 3.36 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.95. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Example  10

Except that 3.18 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 2.00. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Comparative Example  One

Except that 2.62 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.15. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

Comparative Example  2

Except that 2.34 g of terephthaloyl dichloride was added to the mixed solution and reacted at a rotational force of 500 rpm for 6 minutes to prepare a prepolymer having an average molar ratio of para-phenylenediamine to terephthaloyl dichloride of 1.09. In the same manner as in Example 1, a final polymer, poly (paraphenylene terephthal-amide: PPD-T), was prepared.

The average intrinsic viscosity (I.V.) and intrinsic viscosity deviations of the final polymers obtained by the above examples and the comparative examples were measured, and the results shown in Table 2 were obtained.

TABLE 2

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Comparative Example 2 Prepolymer Molar ratio ^{1 )} 1.20 1.40 1.45 1.50 1.60 1.80 1.87 1.90 1.95 2.00 1.15 1.09 Final polymer Average I.V. 4.0 4.4 4.7 4.9 5.1 5.8 5.9 6.0 6.2 6.4 3.1 2.8 I.V. Deviation ± 0.7 ± 0.7 ± 0.6 ± 0.5 ± 0.6 ± 0.5 ± 0.4 ± 0.3 ± 0.5 ± 0.3 ± 1.3 ± 1.1 ¹⁾ molar ratio of para-phenylenediamine to terephthaloyl dichloride

As can be seen from Table 2, when the average molar ratio of the aromatic diamine to the aromatic dieside halide in the prepolymer is less than 1.20, it means that many prepolymers having long molecular chains, that is, high molecular weights, are produced. Not only did the intrinsic viscosity not meet the industry's minimum 4.0 requirement, but the intrinsic viscosity exceeded ± 1.0.

On the other hand, when the average molar ratio of the aromatic diamine to the aromatic dieside halide in the prepolymer is 1.80 or more, it can be seen that a final polymer having an intrinsic viscosity in the range of about 5.8 ± 0.5 (ie, including 6.0 or more) is prepared.

Claims (8)

Dissolving an aromatic diamine in a polymerization solvent to prepare a mixed solution; Preparing a prepolymer by adding an aromatic dieside halide to the mixed solution; And Preparing the final polymer by further adding an aromatic dieside halide to the prepolymer, The prepolymer is a method for producing a wholly aromatic polyamide polymer, characterized in that the molar ratio of the aromatic diamine to the aromatic dieside halide is 1.20 to 2.00. The method of claim 1, The prepolymer is a method for producing a wholly aromatic polyamide polymer, characterized in that the molar ratio of the aromatic diamine to the aromatic dieside halide is 1.80 to 2.00. The method of claim 1, The amount of the aromatic dieside halide added to the mixed solution for the preparation of the prepolymer is 20 to 40% of the total amount of the aromatic dieside halide used for the preparation of the wholly aromatic polyamide polymer. Process for the preparation of amide polymer. The method of claim 1, Using NMR to determine the molar ratio of aromatic diamine to aromatic dieside halide of the prepolymer. The method of claim 4, wherein When the molar ratio of the aromatic diamine to the aromatic dieside halide of the prepolymer measured using the NMR is outside the range of 1.20 to 2.00, changing at least one of the reaction temperature and the reaction time applied during the preparation of the prepolymer. Method for producing a wholly aromatic polyamide polymer, characterized in that it further comprises. Dissolving an aromatic diamine in a polymerization solvent to prepare a mixed solution; Preparing a prepolymer by adding an aromatic dieside halide to the mixed solution, wherein the prepolymer has a molar ratio of aromatic diamine to aromatic dieside halide of 1.20 to 2.00; Preparing a final polymer by further adding aromatic dieside halides to the prepolymer; Preparing a spin dope using the final polymer; And Method for producing aramid fibers comprising the step of spinning the spinning dope. The method of claim 6, The prepolymer is a method for producing aramid fibers, characterized in that the molar ratio of the aromatic diamine to the aromatic dieside halide is 1.8 to 2.0. The method of claim 6, The amount of the aromatic dieside halide added to the mixed solution for the preparation of the prepolymer is 20 to 40% of the total amount of the aromatic dieside halide used for the preparation of the wholly aromatic polyamide polymer. Manufacturing method.