KR101981758B1 - Shaped Cross-section Dope-dyed Meta-Aramid Fiber and Method for producing the same - Google Patents

Abstract

A dope-dyed yarn of the present invention is a modified cross-section meta-aramid dope-dyed yarn having excellent strength and durability by controlling a shape of a fiber. More specifically, the present invention relates to a modified cross-section meta-aramid dope-dyed yarn formed by comprising: a sheath portion formed of a pigment polymeric mixture of meta-aramid dope and pigment; and a core portion formed of meta-aramid dope.

Description

TECHNICAL FIELD The present invention relates to a method for producing a meta-aramid fiber,

TECHNICAL FIELD The present invention relates to a meta-aramid raw material having a modified cross-section and a method for producing the same. More particularly, the present invention relates to a meta-aramid raw material having a high strength and excellent hue and a method for producing the same.

Aramid fiber is a synthetic fiber made from an aromatic polymer that was developed in 1965 with the aim of fiber having strength of fiberglass and heat resistance of asbestos in US Dupont of the United States, . In 1974, the US Federal Trade Commission defined the term "aramid" as the generic name for "aromatic polyamides in which 85% or more amide bonds are directly bonded to two aromatic rings" and then to ISO-2076 and JIS L 0204-2 The name aramid was defined equally.

The aramid is divided into a meta system and a para system by the bonding unit of an amide-bonded aromatic ring. Meta-aramid fibers are excellent in high-temperature heat resistance, and para-aramid fibers have not only high temperature resistance but also high strength and high elasticity.

The meta-aramid is represented by Nomex developed by DuPont, and Conex developed by Dejin. The meta-aramid is a combination of benzene ring and amide group at the meta position. Its strength and elongation are similar to ordinary nylon, but it has very good heat stability. It is light and sweat-absorbing compared to other heat-resistant materials. have. In the early days, the color was limited to a few, but recently it has been made in various colors including fluorescent colors. It is used as fire-resistant clothing, uniforms for racing motorists, astronaut uniforms, work clothes, etc., and for industrial use, it is used for high-temperature filters.

Korean Patent Laid-Open Publication No. 10-2015-0079425 relates to a copolymerized aramid precursor, wherein terephthaloyl dichloride is added to an organic solvent in which an aromatic diamine containing a cyano group is dissolved and reacted to prepare a polymerization solution containing a copolymerized aramid polymer A cationic dye is added to the polymerized solution containing the copolymerized aramid polymer to prepare a copolymerized aramid yarn by spinning and coagulating the polymerized solution, By weight, the polymerization degree of the copolymerized aramid polymer is lowered or the solubility of the polymerization solution is lowered effectively.

The original yarn made of the above-mentioned meta-aramid is generally produced by dispersing the pigment in a meta-aramid polymerized state to produce a post-spinning fiber. However, the viscosity of the polymer used in the meta-aramid spinning is as high as 200,000 cP or more, so that the pigment can not be uniformly dispersed, and the physical properties of the fiber are deteriorated by the addition of the pigment.

In order to solve the above-mentioned problems, the present invention aims to provide a method for producing a modified cross-section meta-aramid original having improved color by improving the degree of dispersion of a pigment in a polymerized state, and a method for producing the same.

Also, it is intended to provide a meta-aramid original closure having a modified hologram having excellent color and improved physical properties, i.e., durability, by controlling the shape of the fiber, and a process for producing the same.

The present invention relates to a sheath portion formed of a pigment polymer mixture of a meta-aramid dope and a pigment; And a core portion formed of meta-aramid dope.

Also, the pigment polymer is 15 to 25 wt% of meta-aramid dope and 1 to 5 wt% of pigment.

Also, the sheath portion and the core portion have a weight ratio of 80:20 to 20:80.

The meta-aramid original yarn has a thickness of 0.3 to 10 denier.

Also provided is a modified meta-aramid original yarn characterized in that the strength of the meta-aramid original yarn is 5.0 g / d or more.

The meta-aramid original yarn has a K / S of 15 or more.

Also, (S1) meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) is dissolved in a polar amide solvent to form a meta-aramid dope step; (S2) diluting the pigment with a polar amide solvent to form a pigment doping; (S3) injecting the pigment dope into a meta-aramid dope to form a meta-aramid-pigment mixture; (S4) adding the meta-aramid-pigment mixture to the meta-aramid dope and stirring the mixture; And (S5) spinning the resultant of step (S1) to a core part and spinning the resultant of step (S4) to a sheath to produce a composite fiber, which is a composite fiber.

Also, the present invention provides a method for producing a meta-aramid raw material having a modified cross-section, wherein the meta-aramid doping in the step (S1) is 15 to 25 wt% and the meta-aramid doping in the step (S3) is 5 to 15 wt% .

Also, the meta-aramid-pigment mixture of step (S3) has a pigment content of 25 to 35 wt%.

The present invention also provides a method for producing a meta-aramid raw material having a modified cross-section, wherein the pigment is present in an amount of 1 to 5 wt%.

In addition, the meta-aramid original yarn has a K / S of 15 or more.

Also, the meta-aramid original yarn has a strength of 5.0 g / d or more.

The meta-aramid original yarn according to the present invention has an effect of providing a meta-aramid original yarn having a uniform cross-section with improved strength and durability by controlling the shape of the fiber.

In addition, the method for producing a meta-aramid raw material according to the present invention has an effect of improving the dispersibility of the pigment to provide excellent color hue, reduce the required amount of pigment for the same color development, The strength is also improved.

1 is a cross-sectional view of a meta-aramid bonded yarn according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation of, or approximation to, the numerical values of manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

As shown in FIG. 1, an embodiment of the present invention forms meta-aramid original yarns of a modified cross-sectional shape. According to an embodiment of the present invention, a meta-aramid raw material of a sheath-core type formed of a sheath portion and a core portion can be formed.

The sheath portion may be formed of a pigment polymer mixed with a meta-aramid dope and a pigment, and the core portion may be formed of a meta-aramid doping.

The meta-aramid dopes of the sheath and core may be formed by dissolving meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) in a polar amide solvent . The polar amide solvent may be selected from the group consisting of dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl formamide (DMF), and dimethyl imidazolidinone Any one of the compounds may be used, and it is preferable to use dimethylacetamide having the most excellent effect.

 The viscosity of the meta-aramid dope is controlled according to the mixing ratio of the polar amide-based solvent and the meta-aramid. When the concentration of the meta-aramid dope is 15 to 25 wt%, the irradiation is suitable. Therefore, the concentration of the meta-aramid dope included in the sheath portion and the core portion is preferably 15 to 25 wt%.

The pigment polymer forming the sheath preferably contains 15 to 25 wt% of meta-aramid dope and 1 to 5 wt% of pigment. When the concentration of the pigment is less than 1 wt%, the color development is insignificant and the function of the original yarn is inferior. When the pigment concentration is more than 5 wt%, the color can be sharp, but the color is difficult to be dispersed, . By controlling the weight ratio of the pigment, it is possible to uniformly express the color of the pigment while maintaining the inherent physical properties of the meta-aramid dope.

The pigment may be any one of organic pigments, inorganic pigments, and fluorescent pigments, or a combination thereof. The pigment is preferably an organic synthetic pigment having a high melting point and excellent thermal stability, and a small amount of a dispersing agent may be added to improve dispersibility.

The sheath portion and the core portion of the sheath-core-type meta-aramid base yarn may be formed at a weight ratio of 80:20 to 20:80.

When the weight ratio of the sheath portion is less than 20, the strength may be increased, but the hue of color may be lowered. If the weight ratio of the sheath portion is more than 80, the hue of color may increase but the strength may be lowered. The weight ratio of the components should preferably be adjusted according to the intended use.

The thickness of the meta-aramid base yarn is preferably 0.3 to 10 denier.

The meta-aramid original yarn according to the present invention has pigments in only the sheath portion and does not include a pigment in the core portion, so that the strength is excellent. Generally, when the pigment is included, it acts as an additive to lower the strength. By separating into a cis-core type to form a crude yarn, a meta-aramid original yarn having a strength of 5.0 g / d or more can be formed.

In addition, since pigments are distributed only in the sheath portion, dyeing properties are superior to those in the case of using general pigments for the same amount of pigments. The original weft yarn according to the present invention may have a K / S of 15 or more, specifically 15 to 25.

Specifically, a method for producing a polygonal cross-section meta-aramid base yarn according to an embodiment of the present invention will be described.

(S1) forming meta-aramid dope by dissolving meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) in a polar amide solvent; (S2) diluting the pigment with a polar amide solvent to form a pigment doping; (S3) injecting the pigment dope into a meta-aramid dope to form a meta-aramid-pigment mixture; (S4) adding the meta-aramid-pigment mixture to the meta-aramid dope and stirring the mixture; And (S5) wet-spinning the resultant product of step (S1) with a core part and the resultant product of step (S4) with a sheath to produce a meta-aramid original compound yarn as a composite fiber.

The concentration of the meta-aramid dope in the step (S1) is preferably 15 to 25 wt%, and the concentration of the meta-aramid dope in the step (S3) is preferably 5 to 15 wt%. By lowering the concentration of the meta-aramid dope in the step (S3) in which the pigment dope is mixed, the degree of dispersion of the input pigment can be increased. If the meta-aramid doping in the step (S3) is performed in the same manner as the meta-aramid doping in the step (S1), the dispersion of the pigment can not be improved and uniform color development is difficult and the strength is lowered. Therefore, it is possible to mix the meta-aramid dope having a relatively low concentration with the pigment to increase the miscibility, and then to increase the degree of dispersion by mixing with the meta-aramid dope having a relatively high concentration. As the degree of dispersion of the pigment increases, the hue of the color becomes excellent and the hue can be uniformly displayed as a whole. Generally, when the pigment is added, the strength of the fiber is lowered. According to the present invention, the amount of the pigment required to develop the same hue is reduced and the strength of the fiber is not lowered, thereby improving the physical properties.

If the concentration of the meta-aramid dope in the step (S3) is lower than 5 wt%, the concentration of the final mixture becomes lower and it is difficult to obtain desired physical properties. If the concentration is higher than 15 wt%, the miscibility of the meta- The strength can be lowered.

The concentration of the pigment in the step (S3) is 25 to 35 wt%, and the concentration of the pigment in the step (S4) is 1 to 5 wt%. If the concentration of the pigment is lower than 25 wt% in the step (S3), the specific gravity of the pigment is lowered overall, and the color development is difficult. If the concentration is higher than 35 wt%, the pigment is relatively large and the dispersibility is lowered, have. If the concentration of the pigment in the step (S4) is less than 1 wt%, the color development is not only insignificant but also the concentration of the final mixture to be radiated is low, so that the spinning may be difficult. If the concentration is higher than 5 wt% The dispersibility is decreased, uniform color development is difficult, and the strength may be lowered.

By controlling the weight ratio of the pigment in steps (S3) and (S4), the pigment can uniformly express the color while maintaining the inherent physical properties of the meta-aramid dope. The pigment may be any one of organic pigments, inorganic pigments, and fluorescent pigments, or a combination thereof. The pigment is preferably an organic synthetic pigment having a high melting point and excellent thermal stability, and a small amount of a dispersing agent may be added to improve dispersibility.

The meta-aramid doping in the step (S4) is the same as the meta-aramid doping in the step (S1), and the meta-aramid doping is preferably 15 to 25 wt%. The viscosity of the meta-aramid dope is controlled according to the mixing ratio of the polar amide-based solvent and the meta-aramid, and is suitable for radiation when the concentration of the meta-aramid dope is 15 to 25 wt%. The spinning step is carried out in a coagulating solution by wet spinning and then stretched to produce fibers.

The coagulating solution is a mixture of a polar amide solvent and water. The polar amide solvent is selected from the group consisting of dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethyl formamide (DMF) Dimethylimidazolidinone. In the present invention, dimethylacetamide is preferably used. The coagulating solution is prepared by mixing 20 to 60% by weight of dimethylacetamide (DMAc), 40% by weight of water 40 To 80 wt% of the total weight of the composition.

In addition, the method for producing a meta-aramid base yarn according to the present invention is a method of directly mixing a 15 to 25 wt% concentration of meta-aramid dope with a concentration of 1 to 5 wt% of a pigment in a polar amide solvent, . It may also be produced by dry spinning.

Hereinafter, the present invention will be described in more detail with reference to examples. It is to be understood, however, that these examples are provided so as to understand the scope of the present invention, and are not to be construed as limiting the scope of the present invention.

Example 1

Meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) was dissolved in dimethylacetamide as a solvent to form a meta-aramid dope at a concentration of 18 wt% . A 5 wt% pigment was mixed with the meta-aramid dope to form a pigment polymer. Using the hollow nozzle, the pigment polymer was injected into the sheath of the nozzle, and the meta-aramid dope was injected into the core part, followed by spinning in the form of a cis-core composite yarn, followed by stretching to produce a meta-aramid original yarn.

Comparative Example  One

Meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) was dissolved in dimethylacetamide as a solvent to form a meta-aramid dope at a concentration of 18 wt% . A 5 wt% pigment was mixed with the meta-aramid dope to form a pigment polymer. The pigment polymer was injected into a nozzle, followed by spinning, and then a meta-aramid raw material was prepared.

◈ Evaluation experiment of examples and comparative examples

Table 1 shows the results of measurement of the concentration and strength of the fibers in the above Examples and Comparative Examples.

* How to measure

(K / S): The surface reflectance was measured at the maximum absorption wavelength of the dyeing fabric using a colorimeter (GretagMacbeth Color-Eye 7000A), and the dyeing concentration (K / S) was calculated according to the Kubelka- To compare the dyeing densities of the dyeing fabrics.

K / S = (1-R) ² / (2R)

(Where K is the extinction coefficient, S is the scattering coefficient, and R is the reflectance)

Strength (g / de): The tensile strength of the fiber is measured using a universal test machine (Instron) according to ASTM D3217.

division Example 1 Comparative Example 1 Soil concentration (K / S) 19 18.5 Strength (g / de) 5.3 4.5 The island (de) 2.0 2.0

As shown in Table 1, it can be confirmed that the Examples have excellent dyeing concentration and strength as compared with Comparative Examples. Compared with the comparative example, the embodiment can exhibit a similar degree of dyeing concentration even when a small amount of pigment is included as a whole, and the pigment is concentrated only on the sheath portion and has excellent strength.

10: meta-aramid original injection 100: meta-aramid dope
200: pigment

Claims (12)

delete delete delete delete delete delete (S1) A meta-aramid polymerized with M-phenylene diamine (MPD) and isophthaloyl chloride (IPC) was dissolved in a polar amide solvent to prepare a meta-aramid dope of 15 to 25 wt% Dope);
(S2) diluting the pigment with a polar amide solvent to form a pigment doping;
(S3) injecting the pigment dope into a meta-aramid dope at a concentration of 5 to 15 wt% to form a meta-aramid-pigment mixture;
(S4) injecting the meta-aramid-pigment mixture into the meta-aramid dope formed in (S1) with a higher meta-aramid concentration; And
(S5) a step of irradiating the resultant product of step (S1) to a core part, and (S4) spinning the resultant product to a sheath part to produce a composite fiber. delete 8. The method of claim 7,
Wherein the meta-aramid-pigment mixture of step (S3) has a pigment concentration of 25 to 35 wt%. 8. The method of claim 7,
Wherein the resultant of step (S4) is a pigment having a concentration of 1 to 5 wt%. 8. The method of claim 7,
Wherein the meta-aramid original yarn has a K / S of 15 or more. 8. The method of claim 7,
Wherein the meta-aramid original yarn has a strength of 5.0 g / d or more.

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