WO2017026746A1 - High strength copolymerized aramid fibers - Google Patents

Abstract

High strength copolymerized aramid fibers, according to the present invention, comprise an aramid copolymer, comprising an aromatic group which substitutes for a cyano group (-CN), and have a chord modulus of 700-1,100g/d. The high strength copolymerized aramid fibers, according to the present invention, has a degree of orientation of 10-25° and enhanced strength of 20-35g/d. The present invention is prepared by means of appropriately adjusting the shear rate in the inner walls of a spinneret when a spinning dope passes through the spinneret or by means of drawing raw aramid yarn, which passes through a coagulation tube, when the raw aramid yarn is coagulated. Therefore, the present invention shows higher chord modulus and strength compared to existing aramid fibers and thus can be utilized as various industrial materials.

Description

High strength copolymerized aramid fiber

The present invention relates to a high-strength copolymerized aramid fiber, specifically, consisting of an aramid copolymer comprising an aromatic group substituted with a cyano group (-CN), the copolymer aramid having a high modulus having a cord modulus of 700 ~ 1,100g / d It is about a fiber.

Aramid fibers include para-aramid fibers and meta-aramid fibers. Among them, para-aramid fiber has excellent properties such as high strength, high elasticity, and low shrinkage. Especially, it has a strong strength enough to lift a 2 ton car with a thin thread of about 5mm thick, and is not only used for bulletproof applications. It is used for various purposes in high-tech industries such as aerospace.

Aramid fibers are typically (i) spinning the aramid spinning dope (Dope) through the spinneret 20, as shown in Figure 1, and (ii) coagulating the spun aramid fibers with the coagulation bath (30) Solidifying while passing through the coagulation tube 40 to which the solid solution is injected, and (iii) washing and neutralizing the coagulated aramid fiber through the at least one flush roller 50 and, if necessary, the neutralizing roller 60 in order. And (iv) washing with water and neutralizing aramid fibers with a drying apparatus 70 and then winding the winding roller 80 in order.

In this case, as an example of a method for producing the aramid spinning dope (Dope) as described in Korean Patent No. 10-0910537 aromatic diamine such as paraphenylenediamine dissolved in an organic solvent to which inorganic salts are added and mixed Prepare a solution, and add aromatic diacid halides such as terephthaloyl dichloride to the mixed solution. After reacting to prepare an aramid polymer, the prepared aramid polymer was dissolved in sulfuric acid to prepare a spinning dope.

The organic solvent may be N-methyl-2-pyrrolidone (NMP), N, N'-dimethylacetamide (DMAc), hexamethylphosphoamide (HMPA), N, N, N ', N'-tetra Methyl urea (TMU), N, N-dimethylformamide (DMF) or mixtures thereof may be used. As the inorganic salt, CaCl ₂ , LiCl, NaCl, KCl, LiBr, KBr, or a mixture thereof may be used.

The aromatic diamine may be para-phenylenediamine, 4,4'-diaminobiphenyl, 2,6-naphthalenediamine, 1,5-naphthalenediamine, or 4,4'-diaminobenzanilide.

The aromatic dieside halide may be terephthaloyl dichloride, 4,4'-benzoyl dichloride, 2,6-naphthalenedicarboxylic acid dichloride, or 1,5-naphthalenedicarboxylic acid dichloride.

The aramid polymer may be polyparaphenylene terephthalamide, poly (4,4'-benzanilide terephthalamide), poly (paraphenylene-4,4'-ratio depending on the type of aromatic diamine and aromatic dieside halide used. Phenylene-dicarboxylic acid amide), or poly (paraphenylene-2,6-naphthalenedicarboxylic acid amide).

As another example of preparing the aramid spinning dope (Dope) as described in Korean Patent No. 10-171994, paraphenylenediamine and cyano-para-phenylene diamine is dissolved in an organic solvent Terephthaloyldichloride was added and reacted to prepare a spinning dope comprising a copolymer aramid polymer containing an aromatic group substituted with a cyano group (-CN). In this case, there is an advantage that the copolymer aramid polymer can be produced by spinning dope (Dope) without the process of dissolving in sulfuric acid.

As the coagulation tube 40 used in the method for producing the aramid fiber has been widely used coagulation tube 40 without grooves formed in the inner wall of the cylindrical body (A) hollow inside, as shown in FIG. The conventional coagulation tube 40 has a problem that can not impart a tensile force to the aramid yarn (Y) passing through the coagulation tube (40).

As another conventional technology, in the Republic of Korea Patent Publication No. 10-2013-0075206 a plurality of grooves (a, the inside of the hollow extending in parallel to the coagulation tube longitudinal direction in the inner wall of the cylindrical body (A) as shown in Figure 3 b, c, d) shows the formed coagulation tube. In the conventional coagulation tube of FIG. 3, grooves are formed on the inner wall of the coagulation tube so that the grooves extend in parallel in the coagulation tube length direction, so that coagulating liquid passes through the coagulation tube through a force flowing in a straight line along the grooves. Although it can be given a certain amount of tensile strength, there was a problem that the tensile force is too weak.

Conventional aramid fibers produced by the methods described above was not enough to stretch during the spinning process, there was a limit to improve the strength and cord modulus to a certain level, impart excessive draw ratio during the spinning process to increase the strength and cord modulus There was a problem of poor radiation operation.

An object of the present invention is to provide a high-strength aramid copolymer aramid fibers composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN) has a cord modulus of 700 ~ 1,100 g / d, the orientation degree 10 ~ 25 ° .

In order to achieve the above object, in the present invention, when spinning the spinning dope through the spinneret, the shear rate at the inner wall of the spinneret is adjusted to 5,000 to 200,000 sec ⁻¹ , and the aramid passes through the coagulation tube. At the same time, the fiber is stretched (tensioned) to improve the cord modulus and strength of the copolymerized aramid fiber without spinning operation.

The present invention is prepared by a method of properly adjusting the shear rate (shear rate) in the inner wall of the spinneret when the spin dope passes through the spinneret or by stretching the aramid yarn passing through the coagulation tube at the same time to solidify the conventional aramid fiber It has a higher code modulus and strength, making it useful for a variety of industrial materials.

1 is a process schematic diagram of making aramid fibers.

2 to 3 is a perspective view of a coagulation tube for producing conventional aramid.

Figure 4 is a perspective view of the coagulation tube used in an embodiment of the present invention.

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

High-strength copolymerized aramid fibers according to the present invention is characterized in that the cord modulus is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN) is 700 ~ 1,100g / d.

The cord modulus is defined as the mean slope at loads ranging from 3 g / d to 4 g / d on an S-S curve in the tensile test.

The present invention comprises a high-strength copolymerized aramid fiber composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN), the cord modulus is 700 ~ 1100g / d, the strength is 20 ~ 35g / d.

The present invention consists of an aramid copolymer comprising an aromatic group substituted with a cyano group (-CN) and comprises a high-strength copolymerized aramid fiber having a cord modulus of 700 to 1100 g / d and an orientation angle of 10 to 25 °.

It is preferable that the high-strength copolymerized aramid fiber which concerns on this invention is 0.5-5 denier in single yarn fineness.

The aramid copolymer including the aromatic group substituted with the cyano group (-CN) has a repeating unit of the following general formula (I).

[In Formula (I), Ar is an aromatic group of the following general formula (II), and A is an aromatic group of the following general formula (III) or of an aromatic group of the general formula (II) Is an aromatic group having a ratio of 1: 9-9: 1]

Various physical properties of the high strength copolymer aramid fibers according to the present invention were evaluated by the following method.

code Modulus (g / d) and strength (g / d)

Tensile properties of aramid fibers were measured according to the ASTM D885 test method. Specifically, the strength of the fiber was determined by pulling until the copolymer aramid fiber having a length of 25 cm was broken in an Instron Engineering Corp. (Cantion, Mass).

At this time, the tensile speed was 300 mm / min, the ultra-load was fineness × 1 / 30g. The number of samples was calculated | required as the average value after testing five. The code modulus was obtained from the slope of the load in the range of 3g / d ~ 4g / d on the S-S curve, and the strength was determined from the maximum load at break.

Orientation

After the Azimutal scan (azimuth scan) at the position of each side of the diffraction pattern obtained through X-ray analysis, the orientation angle was obtained by obtaining the full width at half maximum (FWHM) of each peak.

Next, an example of the manufacturing method of the high strength copolymer aramid fiber of this invention is examined.

The following production method is merely an example of the production of high strength copolymerized aramid fibers of the present invention and should not be construed as limiting the protection scope of the present invention.

First, the present invention performs the step of preparing a spinning dope for producing aramid fibers. Specifically, an inorganic salt is added to the organic solvent to prepare a polymerization solvent, and then paraphenylenediamine and cyano-para-phenylenediamine are dissolved together in the organic solvent or cyano-para-phenylenediamine alone. After dissolving the mixture, a mixed solution was prepared, followed by primary polymerization by adding a small amount of terephthaloyldichloride to the mixed solution while stirring the mixed solution to form a prepolymer in the polymerization solvent.

Thereafter, terephthaloyldichloride was further added to the polymerization solvent to carry out the second polymerization to obtain a spinning dope for preparing aramid, in which a copolymerized aramid copolymer containing an aromatic group substituted with a cyano group (-CN) was dissolved in an organic solvent. Manufacture.

At this time, the organic solvent is N-methyl-2-pyrrolidone (NMP), N, N'- dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA), N, N, N ', N' -Tetramethyl urea (TMU), N, N-dimethylformamide (DMF) or mixtures thereof can be used. As the inorganic salt, CaCl ₂ , LiCl, NaCl, KCl, LiBr, KBr, or a mixture thereof may be used.

Next, after spinning the spinning dope (Dope) prepared as described above as shown in Figure 1 through the spinneret 20, the coagulated bath 30 and the coagulating liquid is injected to the spun aramid fibers After passing through the coagulation tube 40, the coagulated aramid fibers pass through the water washing rollers (50, 60) in turn and washed with water, dried with a drying apparatus (70) and then wound in a winding roller (80) to give a high strength aramid fiber To prepare.

At this time, in one embodiment of the present invention (i) when spinning the spinning dope through the spinneret 20 to adjust the shear rate (Shear rate) in the inner wall of the spinneret 20 to 5,000 ~ 200,000sec ^-1 range and (ii) a plurality of grooves (a) extending in a spiral shape rotating along the longitudinal direction of the coagulation tube on the inner wall of the coagulation tube (A) as shown in FIG. 4 as the coagulation tube 40 shown in FIG. A tensile force is applied to the aramid yarn (Y) passing through the coagulation tube (40) with the rotational force of the coagulation liquid rotating along the grooves (a, b, c, d) using a coagulation tube formed with b, c, d. Grant it.

The shear rate at the inner wall of the spinneret 20 can be adjusted by appropriately combining the size of the hole (diameter) and the discharge amount of the spinneret.

According to the exemplary embodiment of the present invention, since the shear rate in the spinneret inner wall is appropriately adjusted and the aramid fibers are solidified and stretched at the same time in the coagulation tube 40, the stretching ratio is reduced without the deterioration of spinning operation. The copolymerized aramid fibers of the present invention produced by the above embodiment can be improved significantly, and the cord modulus and strength are greatly improved.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

However, the following examples are only examples of preferred embodiments of the present invention and should not be construed as limiting the protection scope of the present invention.

Example  One

An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 50 mol% of p-phenylenediamine and cyano-para- 50 mol% of phenylenediamine (cyano-p-phenylenediamine) was added to the reactor and dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope is spun through the spinneret 20 such that a shear rate at the inner wall of the spinneret is 50,000 sec ⁻¹ , and then the spun aramid fiber is coagulated. The coagulation vessel 30 contained therein and the coagulation solution are sprayed into the coagulation tube of FIG. Next, the aramid fibers passed through the coagulation tube 40, washed with water and neutralized while passing through the water washing roller 50 and the neutralizing roller 60, and then dried with a drying apparatus 70 and wound roller 80 It wound up to produce copolymer aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

Example  2

An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 100 mol% of cyano-p-phenylenediamine was added. Into the reactor was dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope is spun through the spinneret 20 such that a shear rate at the inner wall of the spinneret is 120,000 sec ⁻¹ , and then the spun aramid fibers are coagulated. The coagulation vessel 30 contained therein and the coagulation solution are sprayed into the coagulation tube of FIG. Next, the aramid fibers passed through the coagulation tube 40, washed with water and neutralized while passing through the water washing roller 50 and the neutralizing roller 60, and then dried with a drying apparatus 70 and wound roller 80 It wound up to produce copolymer aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

Example  3

An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 50 mol% of p-phenylenediamine and cyano-para- 50 mol% of phenylenediamine (cyano-p-phenylenediamine) was added to the reactor and dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope was spun through the spinneret 20 such that a shear rate at the inner wall of the spinneret was 12,000 sec ⁻¹ , and then the spun aramid fiber was coagulated. The coagulation vessel 30 contained therein and the coagulation solution are sprayed into the coagulation tube of FIG. Next, the aramid fibers passed through the coagulation tube 40, washed with water and neutralized while passing through the water washing roller 50 and the neutralizing roller 60, and then dried with a drying apparatus 70 and wound roller 80 It wound up to produce copolymer aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

Example  4

An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 100 mol% of cyano-p-phenylenediamine was added. Into the reactor was dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope is spun through the spinneret 20 such that a shear rate at the inner wall of the spinneret is 50,000 sec ⁻¹ , and then the spun aramid fiber is coagulated. The coagulation vessel 30 contained therein and the coagulation solution are sprayed into the coagulation tube of FIG. Next, the aramid fibers passed through the coagulation tube 40, washed with water and neutralized while passing through the water washing roller 50 and the neutralizing roller 60, and then dried with a drying apparatus 70 and wound roller 80 It wound up to produce copolymer aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

Comparative Example  One

An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 50 mol% of p-phenylenediamine and cyano-para- 50 mol% of phenylenediamine (cyano-p-phenylenediamine) was added to the reactor and dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope is spun through the spinneret 20 such that a shear rate at the inner wall of the spinneret is 3,000 sec ⁻¹ , and then the spun aramid fiber is coagulated. While the coagulation bath 30 and the coagulation liquid are injected into the coagulation tube 40 of FIG. 2 (not formed in the inner wall), only coagulation without tension (stretching) is passed through the coagulation tube 40. One aramid fiber was washed with water and neutralized while passing sequentially over the water washing roller 50 and the neutralizing roller 60, and then dried with a drying apparatus 70 and wound on a winding roller 80 to prepare a copolymerized aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

Comparative Example  2

Into the N- methyl-2-pyrrolidone (NMP) an organic solvent containing 3% by weight of CaCl ₂ in the reactor under a nitrogen atmosphere, a-cyano-a-phenylene diamine (cyano-p-phenylenediamine) 100 mole% para Into the reactor was dissolved to prepare a mixed solution.

Subsequently, 100 mol% of terephthaloyl dichloride was added to the reactor containing the mixed solution to prepare a spinning dope including a copolymerized aramid polymer.

Subsequently, as shown in FIG. 1, the spinning dope is spun through the spinneret 20 so that a shear rate at the inner wall of the spinneret is 300,000 sec ⁻¹ , and then the spun aramid fiber is coagulated. Solidification without tension (stretching) while passing through the coagulation tank 30 and the coagulation liquid (40: 4 grooves formed in a form extending in parallel along the longitudinal direction of the coagulation tube) in FIG. Then, the aramid fibers passed through the coagulation tube 40, washed with water and neutralized while passing sequentially over the water roller 50 and the neutralization roller 60, and then dried with a drying apparatus 70 and wound roller 80 It wound up to produce copolymer aramid fiber.

The results of evaluating various physical properties of the prepared copolymer aramid fibers were as shown in Table 1.

division	Code modulus (g / d)	Orientation	Strength (g / d)
Example 1	860	18 °	27
Example 2	1,040	15 °	25
Example 3	940	24 °	21
Example 4	1,090	11 °	34
Comparative Example 1	650	26 °	23
Comparative Example 2	690	22 °	18

* Explanation of the sign

10: Extruder

20: spinneret

30: coagulation tank

40: coagulation tube

50: Suse Roller

60: Chinese roller

70: drying device

80: winding roller

Y: Aramid Yarn

A: main body of the coagulation tube 40

a, b, c, d: grooves of the coagulation tube (40)

The present invention is useful in a variety of industrial materials that require higher cord modulus and strength, such as aviation materials.

Claims (5)

1. A high-strength copolymerized aramid fiber comprising aramid copolymer containing an aromatic group substituted with a cyano group (-CN) has a cord modulus of 700 ~ 1,100g / d.
2. The high strength copolymerized aramid fiber of claim 1, wherein the high strength copolymerized aramid fiber has a strength of 20 to 35 g / d.
3. The high strength copolymerized aramid fiber of claim 1, wherein the high strength copolymerized aramid fiber has a degree of orientation of 10 to 25 degrees.
4. The high strength copolymer aramid fiber according to claim 1, wherein the high strength copolymer aramid fiber has a single yarn fineness of 0.5 to 5 denier.
5. The high-strength copolymerized aramid fiber according to claim 1, wherein the aramid copolymer film comprising an aromatic group substituted with a cyano group (-CN) has a repeating unit of the following general formula (I).

   

   [In Formula (I), Ar is an aromatic group of the following general formula (II), and A is an aromatic group of the following general formula (III) or an aromatic group of the general formula (II) Is an aromatic group having a ratio of 1: 9-9: 1]

   

   

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