KR102140310B1 - Meta-Aramid Fiber of high strength and Method for Preparing the Same - Google Patents

Abstract

The present invention is a polymerization step of preparing meta-aramid resin by polymerizing meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC); A dope manufacturing step of dissolving the meta-aramid resin in a polar amide-based solvent to produce meta-aramid dope, and a fiber manufacturing step of spinning the meta-aramid dope to produce meta-aramid fiber, wherein Phenylene diamine (MPD) and isophthaloyl chloride (IPC) relates to meta-aramid fibers having excellent strength, characterized in that they are polymerized in an equivalent ratio (MPD/IPC) of 0.995 to 0.999, and a method for manufacturing the same.

Description

Meta-Aramid Fiber of high strength and Method for Preparing the Same

The present invention relates to a meta-aramid fiber having excellent strength and a method for manufacturing the same, and a meta-aramid fiber having excellent strength in which the strength of the meta-aramid fiber is improved by adjusting the equivalent ratio of raw materials during metaarimid resin production and a method for manufacturing the same will be.

Aromatic polyamide called aramid, developed in the 1960s, was developed to improve the heat resistance of nylon, an aliphatic polyamide. Aromatic polyamides, well known under the trade names such as Nomex and Kevlar, are flame retardant textile fabrics and tires. It has excellent heat resistance and high tensile strength that can be used for fiber applications such as cords.

A typical aliphatic polyamide is a synthetic resin in which aliphatic hydrocarbons are bonded between amide groups, but aramid is a synthetic resin in which 85% of amide bonds between amide groups are bonded to two aromatic rings. The aliphatic hydrocarbon of the aliphatic polyamide easily undergoes molecular motion when heat is applied, whereas the benzene ring of the aromatic polyamide is stable in heat and has a high elastic modulus because the molecular chain is rigid and the molecule does not easily move when heated. And show many differences in characteristics.

In particular, Metaaramid is representative of Nomex developed by DuPont and Conex developed by Deijin. Meta-aramid is a benzene ring combined with an amide group at the meta position, and its strength and elongation are similar to that of ordinary nylon, but it has very good heat stability, and is lighter than other heat-resistant materials, and has some advantages of being comfortable because it can absorb sweat to some extent. It is used as a material for heat-resistant clothing such as firefighting uniforms, uniforms for racing motorists, astronaut uniforms, and working clothes, and is used as a high-temperature filter for industrial purposes.

Meta-aramid fibers are formed by dissolving meta-aramid dope polymerized with meta-phenylene diamine and isophthaloyl chloride in a solvent to form meta-aramid dope and spinning the meta-aramid dope to form fibers as disclosed in Korean Patent Registration No. 1703349. A polymer solution is prepared by dissolving a meta-type wholly aromatic polyamide containing m-phenylenediamine isophthalamide unit as a main repeating unit in a amide compound solvent, as prepared in a fiber-forming step or as in Korean Patent Registration No. 0490219. A wet spinning step of preparing and extruding the polymer solution into the form of a fiber through a orifice of a spinneret into a coagulation bath containing water and an amide compound solvent but containing substantially no salt and coagulating the resulting fibrous polymer solution in a coagulation bath. Applying a polymer solution; The resulting porous non-stretched fiber formed by coagulation is applied to the stretching step of stretching the fiber in a plastic stretching bath containing an aqueous solution of an amide compound solvent; The resulting stretched fiber was washed with water; And heat treating the washed fibers (eg, further stretching the fibers at an elongation of 0.7 to 3.0 while heating at 270 to 400° C.).

As described above, meta-aramid fibers have excellent heat resistance and are used as various industrial materials, but in strength, they are less than para-aramid fibers, and thus need to be improved in strength to be used for wider applications.

The present invention was invented to solve the problems of the prior art as described above, and meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC) in the polymerization of meta-aramid resin for producing meta-aramid fiber have an equivalent ratio (MPD). /IPC) is to provide a method for manufacturing meta-aramid fibers capable of improving strength.

In addition, an object of the present invention is to provide a meta-aramid fiber having excellent strength produced by the method for manufacturing a meta-aramid fiber.

The present invention is a polymerization step of preparing meta-aramid resin by polymerizing meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC); The meta-aramid resin is dissolved in a polar amide-based solvent to prepare a meta-aramid dope (Dope), a dope production step, spinning the meta-aramid dope to produce a meta-aramid fiber fiber manufacturing step, but in the polymerization step meta- Phenylene diamine (MPD) and isophthaloyl chloride (IPC) provide a method for producing meta-aramid fibers having excellent strength, characterized in that they are polymerized in an equivalent ratio (MPD/IPC) of 0.995 to 0.999.

In addition, the relative viscosity of the meta-aramid resin prepared in the polymerization step is 2.3 to 2.6 provides a method for producing meta-aramid fibers having excellent strength.

In addition, the concentration of meta-aramid resin in the dope manufacturing step provides a method for producing meta-aramid fibers having excellent strength, characterized in that 14 to 20% by weight.

In addition, the meta-aramid dope has an apparent viscosity of 2100 ~ 2750 poise (Poise) provides a method for producing meta-aramid fibers having excellent strength.

In addition, it provides a meta-aramid fiber having excellent strength, characterized in that produced by the above manufacturing method.

As described above, the method for manufacturing meta-aramid fibers having excellent strength according to the present invention is equivalent to the ratio of meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC) when polymerizing meta-aramid resin for producing meta-aramid fiber. IPC) to improve the processability of the meta-aramid fiber and improve the strength.

In addition, through the manufacturing method of the present invention, there is an effect capable of producing meta-aramid fibers having improved strength without additional processes or additives.

1 is a process diagram of a method for manufacturing meta-aramid fibers having excellent strength.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, among the drawings, the same components or parts indicate the same reference numerals as possible. In describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the subject matter of the present invention.

As used herein, the terms'about','substantially', etc. are used in the sense of or close to the numerical values when manufacturing and material tolerances unique to the stated meaning are presented, and the understanding of the present invention. To help, accurate or absolute figures are used to prevent unconscionable abusers from unduly using the disclosed disclosure.

1 is a process diagram of a method for producing meta-aramid fibers having excellent strength, as shown in FIG. 1, the present invention manufactures meta-aramid fibers including a polymerization step, a dope production step, and a fiber production step.

The polymerization step is a step of preparing meta-aramid resin by polymerizing meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC).

In general, when preparing meta-aramid resin, the equivalent ratio of meta-phenylene diamine (MPD) to isophthaloyl chloride (IPC) (MPD/IPC) is important because the physical properties of meta-aramid resins that are manufactured with very small differences are significantly changed. Element.

During meta-aramid polymerization, the higher the meta-phenylene diamine (MPD) equivalents of isophthaloyl chloride (IPC) is, the higher the relative viscosity (RV) of the meta-aramid resin is, the higher the strength of meta-aramid is. Fibers can be produced, but as the relative viscosity of the meta-aramid resin is improved, the apparent viscosity of the meta-aramid dope is greatly increased and the process of manufacturing the fiber is greatly reduced. As a result, the meta-aramid resin used in the fiber is 0.985~1.015. It was prepared at equivalent ratio (MPD/IPC).

The present invention improves the strength of meta-aramid fibers by adjusting the equivalent ratio (MPD/IPC) of meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC) 0.995 to 0.999 in the polymerization step and adjusting the concentration of metaaramid dope. It is an invention that derives the optimum conditions that can be made.

As described above, the present invention is to prepare a meta-aramid resin with an equivalent ratio of meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC) in the polymerization step (MPD/IPC) of 0.995 to 0.999. If the equivalent ratio is less than 0.995, meta The relative viscosity and apparent viscosity of the aramid resin may be greatly increased, thereby deteriorating the fiber manufacturing processability, and when the equivalent ratio exceeds 0.999, it is not expected to improve the strength of the produced meta-aramid fiber.

The relative viscosity of the meta-aramid resin prepared in the polymerization step is preferably 2.3 to 2.6 so that the apparent viscosity of the meta-aramid dope is not significantly increased.

The dope manufacturing step is a step of dissolving the meta-aramid resin in a polar amide-based solvent to prepare a meta-aramid dope.

When the meta-aramid dope is formed, the apparent viscosity of the meta-aramid dope can be adjusted according to the mixing ratio of the polar amide-based solvent and meta-aramid, and it is preferable to adjust the mixing ratio of the polar amide-based solvent and meta-aramid to be suitable for spinning. something to do.

The concentration of meta-aramid dope prepared in the dope manufacturing step is preferably 14 to 20% by weight, and the concentration of meta-aramid dope should be adjusted according to the relative viscosity of the meta-aramid resin used.

In addition, the apparent viscosity of the meta-aramid dope is preferably 2100 ~ 2750 poise (Poise).

The polar amide solvent is dimethyl acetamide (DMAc), N-methylpyrrolidone (N-methylpyrrolidone, NMP), dimethyl formamide (DMF), dimethyl imidazolidinone (Dimethyl imidazolidinone) Either compound can be used, and it is preferable to use dimethylacetamide, which is the most effective.

The fiber manufacturing step is a step of manufacturing the meta-aramid fiber by spinning the meta-aramid dope, and the meta-aramid fiber may be manufactured through a general wet spinning method.

For example, the meta-aramid dope may be wet-spun in a coagulating liquid and stretched to produce meta-aramid fibers.

After the fiber manufacturing step, a heat stretching step, a heat seting step, or the like may be further performed, and a crimp application step may be performed according to the purpose.

The method for manufacturing meta-aramid fibers having excellent strength according to the present invention as described above can synthesize meta-aramid resins used in meta-aramid fibers by adjusting the equivalent ratio and improve the strength of meta-aramid fibers by adjusting the concentration of meta-aramid.

Hereinafter, examples of a method for manufacturing meta-aramid fibers having excellent strength according to the present invention are shown, but the present invention is not limited to the examples.

Example 1 to 4

Meta-aramid resin was prepared by controlling the equivalent ratio according to examples of meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC).

Meta-aramid dope was prepared by dissolving the polymerized meta-aramid in dimethylacetamide as a solvent. The meta-aramid dope was prepared with a meta-aramid concentration of 20% by weight, 18% by weight, and 16% by weight with 14% by weight, respectively.

The meta-aramid dope prepared above was formed by forming a 50° C. coagulation solution of 45% by weight of dimethylacetamide and 55% by weight of water, and then spinning by wet spinning to prepare the meta-aramid fiber after washing.

The washed meta-aramid fibers were hot-stretched at 250 to 350°C, and heat-set at 300 to 450°C to prepare meta-aramid fibers having excellent strength according to the present invention.

The equivalent ratio (MPD/IPC), relative viscosity, and apparent viscosity of the meta-aramid resin according to the above example were measured and are shown in Tables 1 and 2.

Comparative example

In the same manner as in Example 1, the equivalent ratio (MPD/IPC) of metaaramid resin was set to 1.002, and the metaaramid concentration of metaaramid dope was prepared at 20% by weight to prepare metaaramid fibers.

◈ Evaluation experiment of Examples and Comparative Examples

The fineness, strength, and number of trimmings of the meta-aramid fibers prepared in Examples 1 to 4 and Comparative Examples were measured and are shown in Tables 1 and 2.

* RV (relative viscosity): measured using the ASTM-1P-200 method, the solvent was sulfuric acid, and the capillary viscometer was a Kenon-Fensk type. After measuring the time (t0) of the pure solvent and the time (t) of the polymer solution passing through the capillary viscometer in a 35±0.01°C thermostat, the relative viscosity (RV) was obtained using the following equation.

Relative viscosity (RV) = t/t0

* Apparent Viscosity: Metaaramid dope was measured with a Brookfield viscometer at 50°C.

* Fineness and strength were measured by Vibroskop, an analytical facility of Lenzing, and strength/elongation was measured after inputting fineness into Vibrodyn.

* The criterion for trimming recovery is judged to be fair if it is 0.2 times/day or less, fairness is 0.3~5 times/day, and fairness is poor when it is 0.5 times/day or more.

division Comparative example Example
1-1 Example
1-2 Example
1-3 Example
1-4 Example
2-1 Example
2-2 Example
2-3 Example
2-4 Suzy
Properties Equivalence ratio 1.002 0.999 0.996 Relative viscosity 2.21 2.4 2.57 Dope
Properties density
(weight%) 20 20 18 16 14 20 18 16 14 Apparent viscosity
(Poise) 2,520 3,210 2,580 2,110 1,840 3,970 3,240 2,710 2,400 Meta
Aramid
fiber
Properties Fineness (D) 2 2.03 1.98 2.01 2 1.98 1.97 2 1.98 Strength (g/d) 4.57 5.2 5.04 4.78 4.4 6.33 6.2 6.04 5.68 Number of trimming
(Meeting day) 0.1 0.6 0.1 0.4 0.8 1.4 0.7 0.1 0.5

division Example
3-1 Example
3-2 Example
3-3 Example
3-4 Example
4-1 Example
4-2 Example
4-3 Example
4-4 Suzy
Properties Equivalence ratio 0.993 0.990 Relative viscosity 2.67 2.78 Dope
Properties density
(weight%) 20 18 16 14 20 18 16 14 Apparent viscosity
(Poise) 4,670 3,880 3,280 2,820 5,420 4,480 3,810 3,390 Meta
Aramid
fiber
Properties Fineness (D) 2 1.99 2.02 2 2.02 2.03 2 1.99 Strength (g/d) 6.4 6.31 6.16 5.94 6.53 6.41 6.26 6 Number of trimming
(Meeting day) 2.8 1.3 0.8 0.7 4.2 2.6 1.3 1.2

As shown in Tables 1 and 2, it can be seen that the relative viscosity (RV) of the prepared meta-aramid resin increases as the equivalent ratio (MPD/IPC) decreases, and the apparent viscosity increases significantly as the relative viscosity increases. .

When the equivalent ratio (MPD/IPC) is 0.996 to 0.999 as in Example 1 and 2, the strength is increased and the processability is higher than that of the comparative example, but the equivalent ratio (MPD/IPC) is 0.995 or less as in Examples 3 and 4 In the case, although the strength of the fiber increased, it can be seen that the fiber manufacturing processability deteriorates due to the increase in the number of trimming.

In the case of Example 1, the concentration of meta-aramid dope was excellent in the strength and fairness of the meta-aramid fibers of Examples 1-2 and 1-3 in which the concentration of meta-aramid dope was 18% by weight and 16% by weight, and in the case of Example 2, the concentration of meta-aramid dope The meta-aramid fibers of Examples 2-3 and 2-4 having 16% by weight and 14% by weight are excellent in strength and fairness, and the meta-aramid has excellent strength by controlling the concentration of meta-aramid dope according to the equivalent ratio (MPD/IPC). It will be possible to manufacture fibers.

Claims (5)

A polymerization step of preparing meta-aramid resin by polymerizing meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC);
A dope production step of dissolving the meta-aramid resin in a polar amide-based solvent to prepare meta-aramid dope;
Including the fiber manufacturing step of producing a meta-aramid fiber by spinning the meta-aramid dope,
In the polymerization step, meta-phenylene diamine (MPD) and isophthaloyl chloride (IPC) are polymerized in an equivalent ratio (MPD/IPC) 0.996 to 0.999,
The concentration of meta-aramid resin in the dope manufacturing step is 14 to 18% by weight,
The method for producing meta-aramid fibers having excellent strength, characterized in that the relative viscosity of the meta-aramid resin prepared in the polymerization step is 2.3 to 2.6.
delete delete According to claim 1,
The meta-aramid dope has an apparent viscosity of 2100 ~ 2750 poise (Poise), characterized in that excellent strength meta-aramid fiber manufacturing method.
Meta-aramid fiber excellent in strength, characterized in that produced by the method of claim 1 or 4.

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