KR101946318B1 - Method of manufacturing copolymerized aramid fiber and copolymerized aramid fiber manufactured thereby - Google Patents

Abstract

The present invention relates to a method for producing a copolymerized aramid fiber, which comprises polymerizing a polymerization solution containing a copolymerized aramid polymer by adding terephthaloyl dichloride to an organic solvent in which an aromatic diamine containing a cyano group is dissolved, (H ₃ BO ₃ ) is added to the coagulating solution in an amount of 0.1 to 5.0% by weight based on the total weight of the coagulating solution when the coagulated aramid fiber is produced by contacting the radiation with the coagulating solution after spinning the polymerization solution do.
The copolymerized aramid fiber of the present invention is produced by the above method and has a strength of 28 to 35 g / d.
In the present invention, boric acid having excellent affinity with the extraction solvent is added to the coagulating solution to increase the extraction rate of the polymerization solvent in the radiation (fiber) despite the short contact time between the coagulating solution and the radiation (fiber). Therefore, the present invention can produce copolymerized aramid fiber at a high spinning speed without any problem of extraction of a polymerization solvent, thereby improving productivity and minimizing the amount of residual polymerized solvent in the fiber, thereby preventing deterioration of fiber properties.

Description

TECHNICAL FIELD The present invention relates to a method for producing a copolymerized aramid fiber and a copolymerized aramid fiber produced by the method.

The present invention relates to a method for producing a copolymerized aramid fiber and a copolymerized aramid fiber produced by the method. Specifically, when a copolymerized aramid fiber is produced by spinning and coagulating a polymerization solution containing a copolymerized aramid polymer with a spinneret without using sulfuric acid, A method for producing a copolymerized aramid fiber which comprises adding boric acid having excellent affinity to a polymerization solvent in a coagulating liquid to rapidly extract a polymerization solvent remaining in a radiation (fiber) to improve productivity and prevent deterioration of fiber properties, The present invention relates to a copolymerized aramid fiber.

Aromatic polyamides, commonly referred to as aramids, include para-aramids having a structure in which benzene rings are linearly connected through an amide group (CONH), and meta-based aramids that are not.

Para-aramid has excellent properties such as high strength, high elasticity and low shrinkage. The thin thread of 5 mm thickness produced from this has a strength enough to lift a 2-tonne automobile, so it is used not only for bulletproof but also for various applications in the aerospace industry.

In addition, since aramid is carbonized black at a temperature of 500 ° C or higher, it is also in the spotlight where high heat resistance is required.

A method of producing an aramid fiber is well described in Korean Patent Registration No. 10-0910537 of the present applicant. According to this patent, an aromatic diamine is dissolved in a polymerization solvent to prepare a mixed solution, and an aromatic diacid is added to this to prepare an aramid polymer. The aramid fiber is finally completed by dissolving the aramid polymer in a sulfuric acid solvent to prepare a spinning dope, spinning the spinning dope, followed by coagulation, washing, and drying.

However, when the aramid fiber is produced through such a process, since a solid state aramid polymer is prepared and then dissolved again in a sulfuric acid solvent to prepare a spinning dope, the spinning process is complicated and harmful to the human body, And the durability is degraded due to corrosion.

Furthermore, since the sulfuric acid solvent used to dissolve the aramid polymer having high chemical resistance and removed after the spinning causes environmental pollution, it has to be appropriately treated after use. The cost for treating such spent sulfuric acid is not only economical .

In order to solve the above problems, Korean Patent Registration No. 10-171994 discloses a method for producing an aramid fiber without using a sulfuric acid solvent by directly irradiating a copolymerized aramid polymerization solution.

Specifically, in the above prior art, terephthaloyl dichloride is added to an organic solvent in which paraphenylenediamine and cyano-para-phenylenediamine are dissolved and reacted to polymerize the polymerization solution containing the copolymerized aramid polymer, After the solution was spun, the radiation was contacted with coagulating water to prepare copolymerized aramid fibers.

However, in the above-mentioned prior art, there is an advantage that sulfuric acid solvent is not used. However, the extraction rate of the polymerization solvent remaining in the radiation (fiber) is too slow and the coagulation tank is long or large, ), The productivity of the copolymerized aramid fiber was greatly lowered.

On the other hand, when the contact time between the radiation (fiber) and the coagulating liquid (water) is shortened to improve the productivity, the conventional art has a problem that the amount of the residual polymerization solvent in the fiber increases and the physical properties of the fiber such as the strength are greatly deteriorated.

Disclosure of Invention An object of the present invention is to provide a process for producing a copolymerized aramid fiber by using a copolymerized aramid polymerization solvent without the use of sulfuric acid, And to provide a method for rapidly extracting a solvent.

In order to achieve the above object, in the present invention, terephthaloyl dichloride is added to an organic solvent in which an aromatic diamine containing a cyano group is dissolved and reacted to polymerize a polymerization solution containing the copolymerized aramid polymer, And 0.1 to 5.0% by weight of boric acid (H ₃ BO ₃ ) based on the total weight of the coagulating liquid is added to the coagulating liquid when the coagulated aramid fiber is produced by contacting the coagulated aramid fiber with the coagulating liquid.

In the present invention, boric acid having excellent affinity with the extraction solvent is added to the coagulating solution, so that the extraction rate of the polymerization solvent in the radiation (fiber) can be increased despite the short contact time between the coagulating solution and the radiation (fiber). Therefore, the present invention can produce copolymerized aramid fiber at a high spinning speed without any problem of extraction of a polymerization solvent, thereby improving productivity and minimizing the amount of residual polymerized solvent in the fiber, thereby preventing deterioration of fiber properties.

Hereinafter, the present invention will be described in detail.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be apparent to those skilled in the art that variations are possible. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

In the present invention, first, an inorganic salt is dissolved in an organic solvent, and then an aromatic diamine containing a cyano group (-CN) is added and dissolved.

At this time, paraphenylenediamine and cyano-para-phenylenediamine may be dissolved in a molar ratio of 1: 9 to 9: 1 as an aromatic diamine including a cyano group (-CN), or cyano-para-phenylenediamine May be dissolved alone.

Specific examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N, N-dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA) Tetramethylurea (TMU), N, N-dimethylformamide (DMF), or a mixture thereof, and more preferably N-methyl-2-pyrrolidone (NMP).

The inorganic salt is added in order to increase the degree of polymerization of the aromatic polyamide. Specific examples thereof include alkali metal halides such as CaCl ₂ , LiCl, NaCl, KCl, LiBr and KBr, or alkaline earth metal halides. These inorganic salts may be added singly or in the form of a mixture of two or more.

The addition amount of the inorganic salt is preferably about 2 to 5% by weight based on the weight of the organic solvent.

Next, terephthaloyl dichloride is added to the organic solvent in which paraphenylenediamine and cyano-para-phenylenediamine (hereinafter referred to as "aromatic diamine") are added and dissolved in the same molar amount as the aromatic diamine component (Molar amount) to prepare a polymerization solvent containing a copolymerized aramid polymer.

Next, the polymerized solution prepared as described above is extruded through the spinneret using the spinning process as it is, and the extruded spinning coagulates to coagulate the coagulated solution to prepare filamentary co-aramid fibers.

In the present invention, as the coagulating solution, coagulation solution containing 0.1 to 5.0% by weight of boric acid (H ₃ BO ₃ ) added to the total weight of the coagulating solution is used to coagulate the extruded film, And the solvent is extracted at a high speed.

When the content of boric acid in the solidification liquid is less than 0.1 wt%, the effect of extracting the polymerization solvent from the radiation (fiber) becomes insignificant. When the content exceeds 5.0 wt%, the effect of extracting the polymerization solvent is not further improved, .

As an example of the coagulating solution used in the present invention, water in which 0.1 to 5.0% by weight of boric acid (H ₃ BO ₃ ) is added is used.

The boric acid (H ₃ BO ₃ ) has a good affinity with a polymerization solvent such as N-methyl-2-pyrrolidone, and thus helps the polymer solvent remaining in the radiation (fiber) to spread rapidly into the coagulating solution .

The co-aramid fiber prepared according to the present invention has a strength of 28 to 35 g / d.

In the present invention, boric acid having excellent affinity with the extraction solvent is added to the coagulating solution, so that the extraction rate of the polymerization solvent in the radiation (fiber) can be increased despite the short contact time between the coagulating solution and the radiation (fiber). Therefore, the present invention can produce copolymerized aramid fiber at a high spinning speed without any problem of extraction of a polymerization solvent, thereby improving productivity and minimizing the amount of residual polymerized solvent in the fiber, thereby preventing deterioration of fiber properties.

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

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 para-phenylenediamine and 40% 50 mol% of cyano-p-phenylenediamine was dissolved in the reactor to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating solution for 3 seconds while passing through three coagulation baths containing water (coagulation solution) containing 0.5 wt% of boric acid added thereto, thereby solidifying, polymerizing the solvent extraction and washing with water, The dried multifilament was dried and stretched on a drying roller set at a temperature of 150 DEG C, and the drawn multifilament was heat-treated at 250 DEG C and wound up to produce a copolymerized aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

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 The mixture was put into the reactor and dissolved to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating liquid for 3 seconds while passing through three coagulation baths containing 1.0 wt% of boric acid-added water (coagulating solution), and the coagulation, polymerization solvent extraction and water washing were carried out. The dried multifilament was dried and stretched on a drying roller set at a temperature of 150 DEG C, and the drawn multifilament was heat-treated at 250 DEG C and wound up to produce a copolymerized aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

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 para-phenylenediamine and 40% 50 mol% of cyano-p-phenylenediamine was dissolved in the reactor to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating solution for 3 seconds while passing through three coagulation baths containing water (coagulation solution) added with 3.0 wt% of boric acid in order to solidify, polymerize the solvent extraction and wash, The dried multifilament was dried and stretched on a drying roller set at a temperature of 150 DEG C, and the drawn multifilament was heat-treated at 250 DEG C and wound up to produce a copolymerized aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

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 The mixture was put into the reactor and dissolved to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating liquid for 3 seconds while passing through three coagulation baths containing water (coagulating liquid) containing 4.5 wt% of boric acid added thereto, thereby solidifying, polymerizing the solvent extraction and washing with water, The dried multifilament was dried and stretched on a drying roller set at a temperature of 150 DEG C, and the drawn multifilament was heat-treated at 250 DEG C and wound up to produce a copolymerized aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

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 para-phenylenediamine and 40% 50 mol% of cyano-p-phenylenediamine was dissolved in the reactor to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating solution for 3 seconds while passing through three coagulation baths containing water (coagulation solution) not containing boric acid in order to solidify, polymerize and extract the solvent, and then wash the washed multifilaments Dried and stretched on a drying roller set at a temperature of 150 ° C, and the drawn multifilament was heat-treated at 250 ° C and wound up to produce a co-aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

Comparative 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 The mixture was put into the reactor and dissolved to prepare a mixed solution.

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

Subsequently, the polymer solution was extruded through a spinneret, and then passed through an air gap and a coagulating liquid sequentially to form a multifilament having a linear density of 3,000 denier. The pressure in the spinning pack was 2,800 psi and the spinning speed was 600 mpm (meter per minuite).

Then, the multifilament was brought into contact with the coagulating solution for 3 seconds while passing through three coagulation baths containing water (coagulation solution) not containing boric acid in order to solidify, polymerize and extract the solvent, and then wash the washed multifilaments Dried and stretched on a drying roller set at a temperature of 150 ° C, and the drawn multifilament was heat-treated at 250 ° C and wound up to produce a co-aramid fiber.

Table 1 shows the results of evaluating the strength and radioactivity of the copolymerized aramid fibers.

division Strength (g / d) Radioactive Example 1 28.5 Great Example 2 30.0 Great Example 3 31.5 Great Example 4 34.9 Great Comparative Example 1 27.4 Bad Comparative Example 2 27.6 Bad

The strength of the above Table 1 was evaluated in the following manner.

Aramid  Strength of fiber

The strength of the aramid fiber was determined by measuring the strength at the breaking point after stretching until a sample of 25 cm in length was broken in an Instron tester (Instron Engineering Corp, Canton, Mass) according to ASTM D885, Was tested five or more times and then the average value was obtained. At this time, the tensile speed was 300 mm / min, and the initial load was 1 × 30 g of fineness.

Claims (10)

delete delete delete delete delete A polymerization solution containing a copolymerized aramid polymer is polymerized by adding terephthaloyl dichloride to an organic solvent in which an aromatic diamine containing a cyano group (-CN) is dissolved and reacting. After the polymerization solution is spun, (H ₃ BO ₃ ) in an amount of 0.1 to 5.0% by weight based on the total weight of the coagulating liquid when the copolymerized aramid fiber is produced by contacting the coagulated aramid fiber with the coagulating liquid, wherein the coagulated aramid fiber has a strength of 28 to 35 g / d ≪ RTI ID = 0.0 > aramid < / RTI & [7] The method according to claim 6, wherein the organic solvent is an aromatic diamine containing cyano group (-CN) by dissolving paraphenylenediamine and cyano-para-phenylenediamine in a molar ratio of 1: 9 to 9: 1 ≪ / RTI > The co-aramid fiber according to claim 6, wherein the organic solvent is prepared by dissolving cyano-para-phenylenediamine alone as an aromatic diamine containing a cyano group (-CN). 7. The method according to claim 6, wherein terephthaloyl dichloride is added in an organic solvent in which an aromatic diamine containing a cyano group (-CN) is dissolved in the same molar amount as the aromatic diamine containing the cyano group (-CN) Lt; RTI ID = 0.0 > aramid fibers. ≪ / RTI > The co-aramid fiber according to claim 6, which is produced by using water as a coagulating liquid.