KR102400545B1 - Copolymerized aramid fiber with high elasticity - Google Patents

Abstract

The high elastic aramid fiber of the present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN), and has an elasticity modulus of 1,100-1,300 g/d, a strength of 17-30 g/d, and an elongation of 1-4% characterized by being.
In the present invention, the content of the solvent remaining in the fiber is as low as less than 100 ppm, and the crystallinity, crystal size and orientation of the fiber are appropriately controlled by heat treatment, so that the elastic modulus is greatly improved than that of the conventional aramid fiber without a decrease in strength.
The present invention is useful as a material for various products requiring high elasticity as well as high strength properties of aramid fibers.

Description

Copolymerized aramid fiber with high elasticity

The present invention relates to a high elasticity copolymerized aramid fiber, and specifically, it is made of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN), and the crystallinity, crystal size and orientation of the fiber are appropriately controlled by heat treatment. It relates to a copolymer aramid fiber having high elasticity without a decrease in strength.

Aramid fibers include para-aramid fibers and meta-aramid fibers. Among them, para-aramid fiber has excellent characteristics such as high strength, high elasticity, and low shrinkage. In particular, it is used for bulletproof purposes as it has strong enough to lift a 2 ton car with a thin thread of about 5mm thickness. It is used for a variety of purposes in high-tech industries such as aerospace.

Aramid fibers are typically prepared in a process of (i) spinning an aramid spinning dope through a spinneret 20, and (ii) coagulating the spun aramid fibers with a coagulation bath 30, as shown in FIG. The process of coagulating while passing in turn into the coagulation tube 40 to which the solid liquid is sprayed, and (iii) passing the coagulated aramid fiber sequentially over at least one washing roller 50 as shown in FIG. The process of spraying the washing solution on the aramid fiber passing over the washing roller 50 through the washing solution spray nozzle 90 in the It is manufactured by sequentially winding the rollers 80 .

At this time, as an example of a method for manufacturing the aramid spinning dope, as disclosed in Korean Patent No. 10-0910537, an aromatic diamine such as paraphenylenediamine is dissolved in an organic solvent to which an inorganic salt is added and mixed. Prepare a solution, and add an aromatic dieside halide such as terephthaloyl dichloride to the mixed solution. After the reaction was performed to prepare an aramid polymer, the prepared aramid polymer was dissolved in sulfuric acid to prepare a spinning dope.

Examples of the organic solvent include 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. The inorganic salt may be CaCl ₂ , LiCl, NaCl, KCl, LiBr, KBr, or a mixture thereof.

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

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

The aramid polymer is polyparaphenylene terephthalamide, poly(4,4'-benzanilide terephthalamide), poly(paraphenylene-4,4'-bi) depending on the type of aromatic diamine and aromatic diecide halide used. phenylene-dicarboxylic acid amide), or poly(paraphenylene-2,6-naphthalenedicarboxylic acid amide).

As another method for producing the aramid spinning dope (Dope), as disclosed in Korean Patent No. 10-171994, para-phenylenediamine and cyano-para-phenylene diamine are dissolved in an organic solvent. By adding and reacting terephthaloyl dichloride, a spinning dope comprising a copolymer aramid polymer including an aromatic group substituted with a cyano group (-CN) was prepared. In this case, there is an advantage that the copolymer aramid polymer can be prepared as a spinning dope without a process of dissolving it in sulfuric acid.

In the conventional aramid fibers prepared as described above, the organic solvent remaining in the fibers exceeds 100 ppm, or the crystallinity, crystal size and orientation of the fibers by heat treatment are not properly controlled, so the aramid fiber modulus is less than 1,100 g/d. low, and there were problems in that strength and elongation during heat treatment were greatly reduced.

The subject of the present invention is composed of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN), maintaining a strength of 17 to 30 g/d, an elasticity modulus of 1,100 to 1,300 g/d, and an elongation of 1 to 4% It is to provide a high elastic aramid copolymer aramid fiber.

In order to achieve this object, in the present invention, the aramid fiber is washed with water more uniformly and efficiently so that the content of the organic solvent remaining in the aramid fiber is less than 100 ppm, and the crystallinity, crystal size and While properly adjusting the degree of orientation, it improves the modulus of elasticity of aramid fibers without reducing strength.

In the present invention, the content of the solvent remaining in the fiber is as low as less than 100 ppm, and the crystallinity, crystal size and orientation of the fiber are appropriately controlled by heat treatment, so that the elastic modulus is greatly improved than that of the conventional aramid fiber without a decrease in strength.

The present invention is useful as a material for various products requiring high elasticity as well as high strength properties of aramid fibers.

1 is a schematic diagram of a process for producing an aramid fiber.
Figure 2 is a cross-sectional view of the washing roller used in an embodiment of the present invention.
Figure 3 is a schematic view of the process of washing the aramid fiber using the washing roller of Figure 2 in the present invention.
Figure 4 is a schematic view of the process of washing aramid fibers in a conventional method.

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

The high elasticity copolymerized aramid fiber according to 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 1,100-1,300 g/d, a strength of 17-30 g/d, and an elongation of 1- It is characterized by 4%.

The present invention is composed of an aramid copolymer comprising an aromatic group substituted with a cyano group (-CN), and has an elastic modulus of 1,100-1,300 g/d, strength of 17-30 g/d, crystallinity of 60-80%, and crystal size is 100-200 Å (200 planes) and 100-170 Å (110 planes), and the orientation (200 planes) includes high-elasticity copolymerized aramid fibers of 2-9°.

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

[In the 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 following general formula (II) It is an aromatic group with a ratio of 1:9 to 9:1]

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

Crystallinity (%)

Using the diffraction pattern obtained through X-ray analysis, the ratio of the wild peak to the amorphous peak was calculated and measured.

crystal size (Å)

Using the diffraction pattern obtained through X-ray analysis, the full width at half maximum (FWHM) was obtained and calculated using the Scherrer equation.

Strength (g/d), Elongation (%) and Modulus (g/d)

The tensile properties of the aramid fibers were measured according to the ASTM D885 test method. Specifically, the physical properties of the fibers were obtained by stretching the copolymer aramid fibers having a length of 25 cm in an Instron testing machine (Instron Engineering Corp, Cantion, Mass) until they were broken.

At this time, the tensile speed was set to 300 mm/min, and the super load was set to fineness × 1/30 g. The number of samples was obtained as the average value after testing 5 samples. The modulus of elasticity was obtained from the slope on the S-S curve, the strength was obtained from the maximum load at break, and the elongation was obtained from the length at break.

orientation

After performing an azimutal scan at the position of each face of the diffraction pattern obtained through X-ray analysis, the full width at half maximum (FWHM) of each peak was obtained to determine the orientation angle.

Next, look at an example of the manufacturing method of the high elastic copolymer aramid fiber of the present invention.

The following manufacturing method example is only an example of manufacturing the high elasticity copolymerized aramid fiber of the present invention and should not be construed as limiting the protection scope of the present invention.

First, the present invention carries out the step of preparing a spinning dope for manufacturing aramid fibers. Specifically, after preparing a polymerization solvent by adding an inorganic salt to an organic solvent, para-phenylenediamine and cyano-para-phenylenediamine are dissolved together in the organic solvent, or cyano-para-phenylenediamine is used alone After preparing a mixed solution by dissolving the mixture, a small amount of terephthaloyl dichloride is added to the mixed solution while stirring to perform primary polymerization to form a prepolymer in the polymerization solvent.

Then, secondary polymerization is performed by additionally adding terephthaloyl dichloride to the polymerization solvent to prepare a spinning dope for preparing aramid in which a copolymer aramid copolymer containing an aromatic group substituted with a cyano group (-CN) is dissolved in an organic solvent. manufacture

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

Next, as shown in FIG. 1, after spinning the spinning dope prepared as described above through the spinneret 20, the spun aramid fiber is sprayed with the coagulation tank 30 and the coagulating solution After passing in turn into the coagulation tube 40, the coagulated aramid fiber is washed with water while passing in turn over the water washing rollers 50, 60, and then heat-treated in the heat treatment device 70 to determine the degree of crystallinity, crystal size and orientation of the aramid fiber After appropriate control, it is wound on a winding roller 80 to prepare a high elasticity copolymerized aramid fiber.

At this time, in an embodiment of the present invention, as shown in FIG. 2 , the washing liquid injection holes 51 for spraying the washing liquid by centrifugal force generated by the rotation of the washing roller 50 are formed on the surface, and the washing roller 50 ), a hollow washing liquid supply pipe 52 is formed concentrically with the outer periphery of the washing roller 50, and the washing fluid injection ports 51 are in communication with the washing fluid 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 by using a washing roller (50).

Specifically, when the aramid fiber (Y) passes over the washing roller 50, as shown in FIG. 3, the washing solution contained in the washing solution supply pipe 52 formed inside the washing roller 50 is transferred to the washing roller The centrifugal force generated by the rotation of (50) is sprayed in the aramid fiber (Y) direction through the washing liquid injection hole (51) formed on the surface of the washing roller (50).

Therefore, the sprayed washing solution can smoothly penetrate to the inside of the aramid yarn (Y) passing through the washing roller (50), so that the content of the organic solvent remaining in the aramid fiber (Y) can be lowered to less than 100 ppm do.

In addition, in an embodiment of the present invention, the water-washed aramid fiber is heat-treated at a temperature of 250 to 500 ° C. for 0.5 to 20 seconds under a non-strength or a tension of 0.01 to 5 g/d, and the moisture content during heat treatment is adjusted to 5 to 100% does it

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

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

Example 1

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 para-phenylenediamine and cyano-para- A mixed solution was prepared by dissolving 50 mol% of phenylenediamine (cyano-p-phenylenediamine) in the reactor.

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

Then, as shown in FIG. 1, the spinning dope is spun through the spinneret 20, and then the spun copolymer aramid fiber is spun with a coagulation tank 30 containing water (coagulation solution) at 40° C. and 40° C. of coagulating while passing into the coagulation tube 40 to which the water (coagulant) is sprayed, and then coagulating the copolymer aramid fiber that has passed through the coagulation tube 40 continuously, as shown in FIGS. 2 and 3, on the surface of the water washing roller 50 The washing liquid injection ports 51 for spraying the washing liquid by centrifugal force generated by rotation are formed, and the washing liquid which is hollow while forming a concentric circle with the outer circumference of the washing roller 50 inside the washing roller 50 A supply pipe 52 is formed, and the injection holes 51 pass over the washing roller 50 that is in communication with the washing solution supply pipe 52. Copolymer aramid fiber that passes over the washing roller 50 through the washing solution nozzle 51 formed on the surface of the washing roller 50 by centrifugal force generated by the rotation of the washing roller 50 with the washing liquid at 50 ° C. After the process of washing with water by spraying toward the was prepared. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

Example 2

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-para-phenylenediamine was added. It was put in the reactor and melted to prepare a mixed solution.

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

Then, as shown in Figure 1, the spinning dope is spun through the spinneret 20, and then the spun copolymer aramid fibers are spun with a coagulation tank 30 containing water (coagulation solution) at 50° C. and 50° C. of coagulating while passing into the coagulation tube 40 to which the water (coagulant) is sprayed, and then coagulating the copolymer aramid fiber that has passed through the coagulation tube 40 continuously, as shown in FIGS. 2 and 3, on the surface of the water washing roller 50 The washing liquid injection ports 51 for spraying the washing liquid by centrifugal force generated by rotation are formed, and the washing liquid which is hollow while forming a concentric circle with the outer circumference of the washing roller 50 inside the washing roller 50 A supply pipe 52 is formed, and the injection holes 51 pass over the washing roller 50 that is in communication with the washing solution supply pipe 52. Copolymer aramid fiber that passes over the washing roller 50 through the washing liquid nozzle 51 formed on the surface of the washing roller 50 by centrifugal force generated by the rotation of the washing roller 50 with the washing solution, which is water at 60 ° C. After performing the process of washing with water by spraying toward the It was wound to prepare a copolymer aramid fiber. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

Example 3

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 para-phenylenediamine and cyano-para- A mixed solution was prepared by dissolving 50 mol% of phenylenediamine (cyano-p-phenylenediamine) in the reactor.

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

Then, as shown in FIG. 1, the spinning dope is spun through the spinneret 20, and then the spun copolymer aramid fiber is spun with a coagulation tank 30 containing water (coagulation solution) at 40° C. and 40° C. of coagulating while passing into the coagulation tube 40 to which the water (coagulant) is sprayed, and then coagulating the copolymer aramid fiber that has passed through the coagulation tube 40 continuously, as shown in FIGS. 2 and 3, on the surface of the water washing roller 50 The washing liquid injection ports 51 for spraying the washing liquid by centrifugal force generated by rotation are formed, and the washing liquid which is hollow while forming a concentric circle with the outer circumference of the washing roller 50 inside the washing roller 50 A supply pipe 52 is formed, and the injection holes 51 pass over the washing roller 50 that is in communication with the washing solution supply pipe 52. Copolymer aramid fiber that passes over the washing roller 50 through the washing solution nozzle 51 formed on the surface of the washing roller 50 by centrifugal force generated by the rotation of the washing roller 50 with the washing liquid at 50 ° C. After performing the process of washing with water by spraying toward the was prepared. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

Example 4

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-para-phenylenediamine was added. It was put in the reactor and melted to prepare a mixed solution.

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

Then, as shown in FIG. 1, the spinning dope is spun through the spinneret 20, and then the spun copolymer aramid fiber is spun with a coagulation tank 30 containing water (coagulation solution) at 40° C. and 40° C. of coagulating while passing into the coagulation tube 40 to which the water (coagulant) is sprayed, and then coagulating the copolymer aramid fiber that has passed through the coagulation tube 40 continuously, as shown in FIGS. 2 and 3, on the surface of the water washing roller 50 The washing liquid injection ports 51 for spraying the washing liquid by centrifugal force generated by rotation are formed, and the washing liquid which is hollow while forming a concentric circle with the outer circumference of the washing roller 50 inside the washing roller 50 A supply pipe 52 is formed, and the injection holes 51 pass over the washing roller 50 that is in communication with the washing solution supply pipe 52. Copolymer aramid fiber that passes over the washing roller 50 through the washing solution nozzle 51 formed on the surface of the washing roller 50 by centrifugal force generated by the rotation of the washing roller 50 with the washing liquid at 50 ° C. After performing the process of washing with water by spraying toward the was prepared. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

Comparative Example 1

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 para-phenylenediamine and cyano-para- A mixed solution was prepared by dissolving 50 mol% of phenylenediamine (cyano-p-phenylenediamine) in the reactor.

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

Then, as shown in FIG. 1, the spinning dope was spun through the spinneret 20, and then the spun copolymer aramid fibers were treated with a 10% aqueous solution of N-methyl-2-pyrrolidone (NMP) (coagulant). The coagulation tank 30 and the N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulation solution) are coagulated while passing into the sprayed coagulation tube 40, and then continue to the coagulation tube 40 While passing the copolymer aramid fiber that has passed through the washing roller 50 as shown in FIG. 4, the washing solution, which is water at 15° C. ) After performing the process of washing with water by spraying toward the copolymer aramid fiber passing through the stomach twice, heat treatment for 30 seconds at a temperature of 300° C. under a moisture content of 50% and 10 g/d tension with a heat treatment device 70, and then winding It was wound on a roller 80 to prepare a copolymer aramid fiber. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

Comparative Example 2

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-para-phenylenediamine was added. It was put in the reactor and melted to prepare a mixed solution.

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

Then, as shown in FIG. 1, the spinning dope was spun through the spinneret 20, and then the spun copolymer aramid fibers were treated with a 10% aqueous solution of N-methyl-2-pyrrolidone (NMP) (coagulant). The coagulation tank 30 and the N-methyl-2-pyrrolidone (NMP) 10% aqueous solution (coagulation solution) are coagulated while passing into the sprayed coagulation tube 40, and then continue to the coagulation tube 40 While passing the copolymer aramid fiber that has passed through the washing roller 50 as shown in FIG. 4, the washing solution, which is water at 15° C. ) After performing the process of washing with water by spraying toward the copolymer aramid fiber passing through the stomach twice, heat treatment for 30 seconds at a temperature of 500 ° C under 50% moisture content and 10 g / d tension with a heat treatment device 70, and then winding It was wound on a roller 80 to prepare a copolymer aramid fiber. The results of evaluating various physical properties of the prepared copolymer aramid fibers are shown in Table 1.

division Example 1 Example 2 Example 3 Example 4 comparison
Example 1 comparison
Example 2 modulus of elasticity 1,200 1,250 1,110 1,300 900 1,250 Strength (g/d) 24 22 18 30 20 15 Elongation (%) 2.2 3.4 1.2 3.9 4.8 4.5 Orientation (200 pages) 4° 6° 2° 9° 10° 5° Crystallinity (%) 65 78 68 75 57 75 crystal size
(Å) (200 pages) 130 190 110 160 90 180 (p. 110) 125 165 100 155 82 160

10: exteruder 20: spinneret
30: coagulation tank 40: coagulation tube
41: coagulating liquid nozzle Y: aramid fiber
50: Suse roller
70: heat treatment device 80: winding roller 90: washing liquid spray nozzle
J: Washing solution sprayed on aramid fibers
51: washing liquid injection port 52: washing liquid supply pipe

Claims (6)

It is made of an aramid copolymer containing an aromatic group substituted with a cyano group (-CN) and has an elasticity modulus of 1,100 to 1,300 g/d, a strength of 17 to 30 g/d, and an aramid fiber having an elongation of 1 to 4%,
High elasticity copolymerized aramid fiber, characterized in that the content of the organic solvent remaining in the aramid fiber is less than 100ppm. The method according to claim 1, wherein the crystallinity of the high elastic copolymer aramid fiber is 60 to 80%, the crystal size is 100 to 200 Å (200 sides) and 100 to 170 Å (110 sides), and the orientation (200 sides) is 2 to 9°. High elasticity copolymer aramid fiber, characterized in that. [Claim 2] The high elasticity copolymerized aramid fiber according to claim 1, wherein the aramid copolymer comprising an aromatic group substituted with a cyano group (-CN) has a repeating unit of the following general formula (I).

[In the 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 following general formula (II) It is an aromatic group with a ratio of 1:9 to 9:1]

According to claim 1, wherein the aramid fiber is
A process of providing spun copolymer aramid fibers by spinning through a spinneret using a spinning dope for aramid production in which a copolymer aramid copolymer containing an aromatic group substituted with a cyano group in an organic solvent is melted;
A process of coagulating the spun copolymer aramid fiber by passing it through a coagulation tank containing only water and a coagulation tube into which water is sprayed,
Using at least one washing roller with a washing solution injection hole formed on the surface and a washing solution supply pipe formed inside, the aramid fiber is washed by spraying the washing solution so that the content of the organic solvent remaining in the coagulated aramid fiber is less than 100 ppm. flushing process, and
High elasticity copolymerized aramid fiber obtained through a process of drying and winding the washed aramid fiber. 5. The method of claim 4,
A hollow washing solution supply pipe is formed inside the washing roller while forming a concentric circle with the outer circumference of the washing roller,
The washing liquid injection ports are characterized in that in communication with the washing liquid supply pipe,
High elasticity copolymerized aramid fiber. According to claim 4, wherein the coagulation bath is characterized in that it contains 100% by weight of water at 40 °C or 50 °C as a coagulation liquid,
High elasticity copolymerized aramid fiber.

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