JP2018529031A - High-strength copolymer aramid fiber - Google Patents

Abstract

The highly elastic aramid fiber of the present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (—CN), has an elastic modulus of 1,100 to 1,300 g / d, and a strength of 17 to 30 g / d and the elongation is 1 to 4%. In the present invention, the content of the solvent remaining in the fiber is low at less than 100 ppm, and the crystallinity, crystal size, and orientation of the fiber are appropriately controlled by heat treatment. It has the effect of significantly improving over fiber. INDUSTRIAL APPLICABILITY The present invention is useful as a material for various products that require high elasticity as well as high strength characteristics of aramid fibers. [Selection] Figure 1

Description

  The present invention relates to a high-strength copolymerized aramid fiber. More specifically, the present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN). The present invention relates to a copolymerized aramid fiber having a high elasticity without a decrease in strength by appropriately controlling the size and orientation.

  Aramid fibers include para-aramid fibers and meta-aramid fibers. Among these, para-aramid fibers have excellent properties such as high strength, high elasticity, and low shrinkage. In particular, a thin thread having a thickness of about 5 mm is very strong enough to lift a 2 ton weight automobile, and is used not only in bulletproof applications but also in advanced industrial fields such as the aerospace field. Used for various purposes.

  As shown in FIG. 1, the aramid fibers are usually (i) a step of emitting aramid spin dope (Dope) through the spinneret 20, and (ii) a coagulating tank 30 and a coagulating liquid jetting the emitted aramid fibers. A step of coagulating while sequentially passing through the coagulation tube 40, and (iii) the aramid fibers coagulated are sequentially passed on at least one water washing roller 50 as shown in FIG. A step of spraying the water washing liquid onto the aramid fiber passing over the water washing roller 50 through the water washing liquid jet nozzle 90 provided outside the upper stage, and (iv) after drying the water washed aramid fiber with the drying device 70 It is manufactured through the steps of winding around the winding roller 80 in order.

  At this time, as an example of a method for producing the aramid spin dope (Dope), as described in Patent Document 1, an aromatic diamine such as paraphenylenediamine is dissolved in an organic solvent to which an inorganic salt is added. A mixed solution is prepared, and an aromatic diacid halide such as terephthalic acid dichloride is added to the mixed solution and reacted to produce an aramid polymer. Thereafter, the produced aramid polymer was dissolved in sulfuric acid to produce a spin dope.

Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N, N′-dimethylacetamide (DMAc), hexamethylphosphoric acid amide (HMPA), N, N, N ′, N′-tetramethylurea. (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 can be used.

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

  The aromatic diacid halide may be terephthalic acid 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) depending on the type of aromatic diamine and aromatic diacid halide used. '-Biphenylene-dicarboxylic acid amide) or poly (paraphenylene-2,6-naphthalenedicarboxylic acid amide).

  As another example of the method for producing the aramid spin dope (Dope), as described in Patent Document 2, terephthalic acid dichloride is dissolved in an organic solvent in which paraphenylenediamine and cyano-para-phenylenediamine are dissolved. A spin dope containing a copolymerized aramid polymer containing an aromatic group substituted with a cyano group (—CN) was added and reacted. In such a case, there is an advantage that the copolymer aramid polymer can be produced by spin dope even without a step of dissolving the copolymer in sulfuric acid.

  The conventional aramid fiber manufactured as described above has a modulus of elasticity of the aramid fiber because the organic solvent remaining in the fiber exceeds 100 ppm or the crystallinity, crystal size and orientation of the fiber are not properly controlled by heat treatment. Is less than 1,100 g / d, and there is a problem that strength and elongation during heat treatment are greatly reduced.

Korean Patent Registration No. 10-0910537 Korean Patent Registration No. 10-171994

  The subject of this invention is comprised with the aramid copolymer containing the aromatic group by which the cyano group (-CN) was substituted, and an elasticity modulus is 1,100-1, maintaining the intensity | strength of 17-30 g / d. The object is to provide a highly elastic aramid copolymer aramid fiber having an excellent elongation of 300 g / d and an elongation of 1 to 4%.

  In order to achieve such a problem, in the present invention, the aramid fiber is washed more uniformly and efficiently so that the content of the organic solvent remaining in the aramid fiber is less than 100 ppm, and the heat treatment step While adjusting the crystallinity, crystal size, and orientation degree of an aramid fiber appropriately through the strength, the elastic modulus of the aramid fiber can be improved without lowering the strength.

  In the present invention, the content of the solvent remaining in the fiber is low at less than 100 ppm, and the crystallinity, crystal size, and orientation of the fiber are appropriately controlled by heat treatment. It has the effect of significantly improving over fiber.

  INDUSTRIAL APPLICABILITY The present invention is useful as a material for various products that require high elasticity as well as high strength characteristics of aramid fibers.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
The high-strength copolymer aramid fiber according to the present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (—CN), has an elastic modulus of 1,100 to 1,300 g / d, and has a strength Is 17 to 30 g / d, and the elongation is 1 to 4%.

  The present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (—CN), and has an elastic modulus of 1,100 to 1,300 g / d and a strength of 17 to 30 g / d. High-strength copolymer having a crystallinity of 60 to 80%, a crystal size of 100 to 200 mm (200 planes) and 100 to 170 mm (110 planes), and an orientation degree (200 planes) of 2 to 9 °. Contains aramid fiber.

The aramid copolymer containing an aromatic group substituted with the cyano group (—CN) has a repeating unit represented by the following general formula (1).

(In the formula (1), Ar is an aromatic group of the following general formula (2), and the A is an aromatic group of the following general formula (3) or an aromatic group of the following general formula (2) (It is an aromatic group in which the ratio of the aromatic group of the general formula (3) is 1: 9 to 9: 1.)

Various physical properties of the high-strength copolymer aramid fiber according to the present invention were evaluated by the following methods.
Crystallinity (%)
Using the diffraction pattern obtained through X-ray analysis, the ratio of the crystal peak to the amorphous peak was determined and measured.

Crystal size (Å)
The full width at half maximum (FWHM) was obtained using the diffraction pattern obtained through the X-ray analysis, and was calculated using Scherrer's equation.

Strength (g / d), elongation (%) and elastic modulus (g / d)
Tensile properties of aramid fibers were measured by ASTM D885 test method. Specifically, the properties of the fiber were determined by stretching the copolymer aramid fiber having a length of 25 cm with an Instron testing machine (Instron Engineering Corp, Canton, Mass) until it broke.

  At this time, the tensile speed was 300 mm / min, and the initial load was fineness × 1/30 g. The number of samples was 5. After testing this, the average value was obtained. The elastic modulus was determined from the slope on the SS curve, the strength was the maximum load at break, and the elongation was determined from the length at break.

After performing an azimuth scan at the position of each surface of the diffraction pattern obtained through orientation degree X-ray analysis, the half width of each peak (FWHM: Full Width at Half Maximum) is obtained and the orientation angle is determined. Asked.

  Next, an example of the manufacturing method of the high intensity | strength copolymer aramid fiber which concerns on this invention is demonstrated.

  An example of the production method described below is only one embodiment for producing the high-strength copolymer aramid fiber of the present invention, and should not be construed as limiting the protection scope of the present invention.

  First, the present invention applies a step of manufacturing a spin dope for manufacturing an aramid fiber. Specifically, after preparing an polymerization solvent by adding an inorganic salt to an organic solvent, paraphenylenediamine and cyano-para-phenylenediamine are dissolved together in the organic solvent, or cyano-para-phenylenediamine is used alone. To prepare a mixed solution, and then, while stirring the mixed solution, a small amount of terephthalic acid dichloride is added to the mixed solution to perform primary polymerization, and a prepolymer in a polymerization solvent is obtained. Form.

  Next, secondary polymerization is performed by further adding terephthalic acid dichloride to the polymerization solvent, and a copolymerized aramid copolymer containing an aromatic group substituted with a cyano group (—CN) is dissolved in the organic solvent. A spin dope for producing aramid is produced.

In this case, as the organic solvent, N-methyl-2-pyrrolidone (NMP), N, N′-dimethylacetamide (DMAc), hexamethylphosphoric acid amide (HMPA), N, N, N ′, N′— Tetramethylurea (TMU), N, N-dimethylformamide (DMF), or a mixture thereof can be used. As the inorganic salt, CaCl ₂ , LiCl, NaCl, KCl, LiBr, KBr, or a mixture thereof can be used.

  Next, as shown in FIG. 1, after the spin dope (Dope) manufactured as described above is radiated through the spinneret 20, the radiated aramid fiber is coagulated in the coagulation tank 30 and the coagulation tube 40 in which the coagulation liquid is injected. Then, the solidified aramid fiber is washed with water while sequentially passing on the washing rollers 50 and 60. Then, it heat-processes with the heat processing apparatus 70, while controlling the crystallinity degree, crystal size, and orientation degree of an aramid fiber appropriately, it winds up by the winding roller 80, and manufactures a high intensity | strength copolymer aramid fiber.

  At this time, in one embodiment of the present invention, as shown in FIG. 2, a flushing liquid injection port 51 for ejecting flushing liquid by centrifugal force generated by the rotation of the flushing roller 50 is formed on the surface. A washing water supply pipe 52 that is hollow while being concentric with the outer circumference of the washing roller 50 is formed inside the washing water supply pipe 52, and the washing water injection port 51 communicates with the washing water supply pipe 52. The aramid fiber Y is washed with water so that the content of the organic solvent remaining in the aramid fiber Y is less than 100 ppm.

  Specifically, when the aramid fiber Y passes over the water washing roller 50, as shown in FIG. 3, the water washing liquid put in the water washing liquid supply pipe 52 formed inside the water washing roller 50 is The water is sprayed in the direction of the aramid fiber Y through the water washing liquid injection port 51 formed on the surface of the water washing roller 50 by centrifugal force generated by the rotation of the water washing roller 50.

  Therefore, the sprayed washing water can smoothly penetrate into the aramid yarn Y passing through the washing roller 50, and the content of the organic solvent remaining in the aramid fiber Y can be reduced to less than 100 ppm. become.

  In one embodiment of the present invention, the aramid fiber subjected to the water washing treatment is heat-treated at a temperature of 250 to 500 ° C. under no tension or under a tension of 0.01 to 5 g / d for 0.5 to 20 seconds. The water content is adjusted to 5 to 100%.

Hereinafter, the present invention will be described in detail through examples and comparative examples.
However, the following examples are merely examples for helping understanding of the present invention, and should not be construed as limiting the scope of the present invention in any way.

[Example 1]
An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3 wt% CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 50 mol% of p-phenylenediamine and cyano-para-phenylenediamine were added. (Cyano-p-phenylenediamine) 50 mol% was put into the reactor and dissolved to prepare a mixed solution.

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after irradiating the spin dope through the spinneret 20, the radiated copolymer aramid fiber is mixed with a coagulation tank 30 containing 40 ° C. water (coagulation liquid) and a 40 ° C. The water (coagulating liquid) is solidified while being passed through the coagulating tube 40 to be sprayed. Subsequently, as shown in FIG. 2 and FIG. 3, the washing liquid injection port 51 for injecting the washing liquid by centrifugal force generated by the rotation of the washing roller 50 is formed on the surface of the copolymerized aramid fiber that has passed through the coagulation tube 40. A flushing water supply pipe 52 that is concentric with the outer circumferential circle of the flushing roller 50 is formed inside the flushing roller 50, and the nozzle 51 communicates with the flushing liquid supply pipe 52. While being passed over the washing roller 50, the washing water 50, which is water at 50 ° C. put in a washing solution supply pipe 52 formed inside the washing roller 50, is generated by the centrifugal force generated by the rotation of the washing roller 50. The step of rinsing with water by spraying onto the copolymerized aramid fibers passing over the rinsing roller 50 through the rinsing liquid injection port 51 formed on the surface of the rinsing was performed twice. Subsequently, heat treatment was performed for 10 seconds at a temperature of 400 ° C. under conditions of 10% moisture and no tension in the heat treatment apparatus 70, and then wound around a take-up roller 80 to produce copolymer aramid fibers. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

[Example 2]
An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ is placed in a reactor under a nitrogen atmosphere, and 100 mol% of cyano-p-phenylenediamine is reacted with the reaction. A mixed solution was prepared by dissolving in a vessel.

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after irradiating the spin dope through the spinneret 20, the irradiated copolymer aramid fiber is mixed with a coagulation tank 30 containing 50 ° C. water (coagulation liquid) and a 50 ° C. The water (coagulating liquid) is solidified while being passed through the coagulating tube 40 to be sprayed. Subsequently, as shown in FIG. 2 and FIG. 3, the washing liquid injection port 51 for injecting the washing liquid by centrifugal force generated by the rotation of the washing roller 50 is formed on the surface of the copolymerized aramid fiber that has passed through the coagulation tube 40. A flushing water supply pipe 52 that is concentric with the outer circumferential circle of the flushing roller 50 is formed inside the flushing roller 50, and the nozzle 51 communicates with the flushing liquid supply pipe 52. While being passed over the washing roller 50, the washing water 50, which is 60 ° C. water contained in a washing solution supply pipe 52 formed inside the washing roller 50, is generated by the centrifugal force generated by the rotation of the washing roller 50. The step of rinsing with water by spraying onto the copolymerized aramid fibers passing over the rinsing roller 50 through the rinsing liquid injection port 51 formed on the surface of the rinsing was performed twice. Subsequently, heat treatment was performed for 10 seconds at a temperature of 400 ° C. under a tensile condition of 10% moisture and 0.5 g / d with a heat treatment apparatus 70, and then wound around a take-up roller 80 to produce a copolymer aramid fiber. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

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

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after irradiating the spin dope through the spinneret 20, the radiated copolymer aramid fiber is mixed with a coagulation tank 30 containing 40 ° C. water (coagulation liquid) and a 40 ° C. The water (coagulating liquid) is solidified while being passed through the coagulating tube 40 to be sprayed. Subsequently, as shown in FIG. 2 and FIG. 3, the washing liquid injection port 51 for injecting the washing liquid by centrifugal force generated by the rotation of the washing roller 50 is formed on the surface of the copolymerized aramid fiber that has passed through the coagulation tube 40. A flushing water supply pipe 52 that is concentric with the outer circumferential circle of the flushing roller 50 is formed inside the flushing roller 50, and the nozzle 51 communicates with the flushing liquid supply pipe 52. While being passed over the washing roller 50, the washing water 50, which is water at 50 ° C. put in a washing solution supply pipe 52 formed inside the washing roller 50, is generated by the centrifugal force generated by the rotation of the washing roller 50. The step of rinsing with water by spraying onto the copolymerized aramid fibers passing over the rinsing roller 50 through the rinsing liquid injection port 51 formed on the surface of the rinsing was performed twice. Subsequently, the heat treatment apparatus 70 was heat treated at a temperature of 450 ° C. for 15 seconds under a condition of 20% moisture and no tension, and then wound around a take-up roller 80 to produce copolymer aramid fibers. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

[Example 4]
An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ is placed in a reactor under a nitrogen atmosphere, and 100 mol% of cyano-p-phenylenediamine is reacted with the reaction. A mixed solution was prepared by dissolving in a vessel.

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after irradiating the spin dope through the spinneret 20, the radiated copolymer aramid fiber is mixed with a coagulation tank 30 containing 40 ° C. water (coagulation liquid) and a 40 ° C. The water (coagulating liquid) is solidified while being passed through the coagulating tube 40 to be sprayed. Subsequently, as shown in FIG. 2 and FIG. 3, the washing liquid injection port 51 for injecting the washing liquid by centrifugal force generated by the rotation of the washing roller 50 is formed on the surface of the copolymerized aramid fiber that has passed through the coagulation tube 40. A flushing water supply pipe 52 that is concentric with the outer circumferential circle of the flushing roller 50 is formed inside the flushing roller 50, and the nozzle 51 communicates with the flushing liquid supply pipe 52. While being passed over the washing roller 50, the washing water 50, which is water at 50 ° C. put in a washing solution supply pipe 52 formed inside the washing roller 50, is generated by the centrifugal force generated by the rotation of the washing roller 50. The step of rinsing with water by spraying onto the copolymerized aramid fibers passing over the rinsing roller 50 through the rinsing liquid injection port 51 formed on the surface of the rinsing was performed twice. Subsequently, the heat treatment apparatus 70 was heat treated at a temperature of 450 ° C. for 15 seconds under a condition of 20% moisture and no tension, and then wound around a take-up roller 80 to produce copolymer aramid fibers. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

[Comparative Example 1]
An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3 wt% CaCl ₂ was placed in a reactor under a nitrogen atmosphere, and 50 mol% of p-phenylenediamine and cyano-para-phenylenediamine were added. (Cyano-p-phenylenediamine) 50 mol% was put into the reactor and dissolved to prepare a mixed solution.

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after the spin dope is radiated through the spinneret 20, the radiated copolymer aramid fiber is charged with N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulating liquid). The coagulation tank 30 and the N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulation liquid) are coagulated while being passed through the coagulation tube 40 that is jetted. Subsequently, the copolymerized aramid fiber that has passed through the coagulation tube 40 is passed through the washing roller 50 as shown in FIG. The water washing liquid was sprayed toward the copolymerized aramid fiber passing over the water washing roller 50 and washed twice. Subsequently, the heat treatment apparatus 70 was subjected to heat treatment at a temperature of 300 ° C. for 30 seconds under a moisture of 50% and a tension of 10 g / d, and then wound around a take-up roller 80 to produce a copolymer aramid fiber. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

[Comparative Example 2]
An N-methyl-2-pyrrolidone (NMP) organic solvent containing 3% by weight of CaCl ₂ is placed in a reactor under a nitrogen atmosphere, and 100 mol% of cyano-p-phenylenediamine is reacted with the reaction. A mixed solution was prepared by dissolving in a vessel.

  Next, 100 mol% of terephthalic acid dichloride was added to the reactor containing the mixed solution to produce a spin dope containing a copolymerized aramid polymer.

  Subsequently, as shown in FIG. 1, after the spin dope is radiated through the spinneret 20, the radiated copolymer aramid fiber is charged with N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulating liquid). The coagulation tank 30 and the N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulation liquid) are coagulated while being passed through the coagulation tube 40 that is jetted. Subsequently, the copolymerized aramid fiber that has passed through the coagulation tube 40 is passed through the washing roller 50 as shown in FIG. The water washing liquid was sprayed toward the copolymerized aramid fiber passing over the water washing roller 50 and washed twice. Subsequently, the heat treatment apparatus 70 was subjected to heat treatment at a temperature of 500 ° C. for 30 seconds under a moisture of 50% and a tension of 10 g / d, and then wound around a take-up roller 80 to produce a copolymer aramid fiber. Various physical properties of the produced copolymer aramid fibers were evaluated, and the results were as shown in Table 1 below.

  INDUSTRIAL APPLICABILITY The present invention is useful as a material for various products that require high elasticity as well as high strength characteristics of aramid fibers such as bulletproof materials.

It is the schematic which shows the process of manufacturing an aramid fiber. It is sectional drawing of the washing roller used by one Embodiment of this invention. It is a schematic diagram which shows the process of rinsing an aramid fiber using the washing roller of FIG. 2 by this invention. It is a schematic diagram which shows the process of washing aramid fiber with the conventional method.

DESCRIPTION OF SYMBOLS 10 Extruder 20 Spinneret 30 Coagulation tank 40 Coagulation tube 41 Coagulation liquid injection port Y Aramid fiber 50 Water washing roller 70 Heat processing apparatus 80 Winding roller 90 Water washing liquid injection nozzle J Water washing liquid in which an aramid fiber is injected 51 Water washing liquid injection port 52 Washing liquid supply pipe

Claims (3)

  It is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (—CN), has an elastic modulus of 1,100 to 1,300 g / d, a strength of 17 to 30 g / d, and an elongation. Is a high-strength copolymerized aramid fiber, characterized in that it is 1 to 4%.   The crystallinity of the high-strength copolymerized aramid fiber is 60 to 80%, the crystal sizes are 100 to 200 mm (200 planes) and 100 to 170 mm (110 planes), and the degree of orientation (200 planes) is 2 to 9 °. The high-strength copolymerized aramid fiber according to claim 1, wherein The high-strength copolymer aramid fiber according to claim 1, wherein the aramid copolymer containing an aromatic group substituted with a cyano group (-CN) has a repeating unit represented by the following general formula (1).

(In the formula (1), Ar is an aromatic group of the following general formula (2), and the A is an aromatic group of the following general formula (3) or an aromatic group of the following general formula (2) (It is an aromatic group in which the ratio of the aromatic group of the general formula (3) is 1: 9 to 9: 1.)

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