KR101946069B1 - The method of manufacturing Meta-aramid conjugated fiber and Meta-aramid conjugated fiber Produced thereof - Google Patents

Abstract

The present invention relates to a method for producing a meta-aramid conjugate fiber and a meta-aramid conjugate fiber produced by the method, and thus it is possible to provide a different shrinkage ratio.
Furthermore, the method for producing the meta-aramid conjugated fiber of the present invention as described above and the products manufactured using the meta-aramid conjugated fiber produced by the method can provide excellent bulky properties.

Description

METHOD OF MANUFACTURING META-ARAMIDE COMPLEX FIBER AND META-ARAMIDE COMPLEX FIBER OBTAINED THEREFROM,

The present invention relates to a method for producing a meta-aramid conjugate fiber and a meta-aramid conjugate fiber produced thereby, and more particularly to a method for producing a meta-aramid conjugate fiber which provides excellent heat resistance and crimp ratio, Lt; / RTI >

Generally, polyamide-based synthetic resins are classified into aliphatic polyamides and aromatic polyamides. Aliphatic polyamides are generally known under the trade name Nylon, and aromatic polyamides are known under the trade name Aramid. The aliphatic polyamide. Especially, nylon 6 and nylon 6,6 are the most common thermoplastic engineering plastics, and they are used not only as fibers but also as molding materials in various fields. The nylon resin used in the molding industry is made of reinforced plastics which is reinforced with mineral or glass fiber to improve mechanical properties such as elasticity and lowering the price to have improved flame retardancy and impact resistance.

In contrast to the molecular motion, the benzene ring of the aromatic polyamide has a strong molecular chain and does not easily move even when heat is applied. Therefore, the benzene ring of the aromatic polyamide shows a large difference in characteristics from the aliphatic polyamide because of its stability to heat and high elasticity.

The aromatic polyamide is classified into a para-aramid and a meta-aramid. The para-aramid is represented by Kevlar developed by DuPont. The para-aramid is the benzene ring bound to the amide group at the para position. Since the molecular chain is very stiff and has a linear structure, it has a very high strength and a particularly high elasticity, so that it has excellent shock absorbing performance. It is used for armor, bulletproof helmet, safety gloves, boots and fire extinguisher. It is used for sports equipment such as sticks, fishing rods and golf clubs, and also for industrial use such as FRP (Fiber Reinforced Plastics) and asbestos replacement fibers. 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 is very stable against heat. 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.

On the other hand, the conventional conjugated fiber has been widely used as a composite fiber using two different polymers. Among them, the combination of nylon, polyester, nylon and polyurethane had various problems such as unevenness due to dyeing, weakness of crimp due to lack of compatibility, and division problem in post-process.

In order to solve these problems, there is a manufacturing method in which a distribution plate and a spinneret are specially manufactured to prevent the occurrence of a projecting phenomenon. However, this method has a problem in that the manufacturing cost is increased due to the complexity of the apparatus.

However, since the meta-aramid fiber has to satisfy high heat resistance and high strength, it is difficult to use the composite aramid fiber in combination with other kinds of polymers.

In addition, the existing meta-aramid composite fibers have a problem that it is difficult to realize various desired properties such as bulkiness and water repellency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for producing a meta-aramid conjugate fiber capable of producing a product having a bulky property and a meta- .

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a process for preparing a polymer composition comprising: (1) a first composition comprising a first meta-aramid polymer and a first solvent; And a second composition comprising a second meta-aramid polymer and a second solvent having a diffusion coefficient different from that of the first solvent; And (2) composite spinning the first composition and the second composition to produce a conjugate fiber. The present invention also provides a method for producing the meta-aramid conjugate fiber having the shrinkage characteristics.

According to a preferred embodiment of the present invention, the first meta-aramid polymer and the second meta-aramid polymer may include those copolymerized with an aromatic diamine and an aromatic diacid chloride.

According to a preferred embodiment of the present invention, the composite spinning may be dry spinning, in which the meta-aramid conjugated fiber discharged from the spinneret is separated and removed through the hot gas in the spinneret by the first solvent and the second solvent And the hot gas may be 60 to 250 ° C.

According to a preferred embodiment of the present invention, the meta-aramid composite fiber may be of a side by side type.

Another aspect of the present invention provides a meta-aramid conjugate fiber having the shrinkage characteristics, the meta-aramid conjugate fiber comprising at least two meta-aramid components having different heat shrinkage ratios, wherein the difference in thermal contraction ratio between the two or more meta-aramid components can be between 1000 and 50,000 ppm , The meta-aramid component may comprise a copolymer comprising an aromatic diamine and an aromatic diacid chloride, wherein the meta-aramid component is selected from the group consisting of poly (metaphenylene isophthalamide), poly (m-benzamide), poly (M, m'-phenylene benzamide), and poly (1,6-naphthylene isophthalamide), and the composite fiber may be at least one selected from the group consisting of poly May be of the side by side type. Further, the meta-aramid single fineness may be 1 to 10 denier.

The meta-aramid conjugate fiber produced by the method of the present invention has shrinkage characteristics and high flexibility without forming a composite yarn with other materials such as PET.

1 is a cross-sectional view of a radiation tube used in the present invention.
2 is a cross-sectional view of a side-by-side type composite fiber according to a preferred embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the accompanying drawings.

As described above, conventionally, there has been a problem in that different shrinkage characteristics can not be exhibited with the same components.

Thus, according to one aspect of the present invention, there is provided a composition comprising: (1) a first composition comprising a first meta-aramid polymer and a first solvent; And a second composition comprising a second meta-aramid polymer and a second solvent having a diffusion coefficient different from that of the first solvent; And (2) composite spinning the first composition and the second composition to produce a conjugated fiber. The present invention also provides a method for producing a composite fiber having a bulky property, do.

First, a first composition comprising the first meta-aramid polymer and the first solvent as the step (1); And a second composition comprising a second meta-aramid polymer and a second solvent having a diffusion coefficient different from that of the first solvent.

According to a preferred embodiment of the present invention, the first meta-aramid polymer and the second meta-aramid polymer may include those copolymerized with an aromatic diamine and an aromatic diacid chloride.

Specifically, the aromatic diamine can be generally used as metaphenylenediamine, and the aromatic diacid chloride can be polymerized by reacting isophthaloyl chloride as a raw material in the following reaction formula (1).

 [Reaction Scheme 1]

The polymerization process may be carried out by stirring the m-phenylenediamine and isophthaloyl chloride in an amide-based solvent to form a polymethenylene isophthaloyl chloride by a polymerization reaction. The m-phenylenediamine and isophthaloyl chloride are reacted at a similar molar ratio And more preferably, 5 to 15 parts by weight of metaphenylenediamine and 10 to 30 parts by weight of isophthaloyl chloride are mixed and polymerized in 100 parts by weight of the amide solvent. The amide-based solvent is preferably a polar amide-based solvent, and it is preferable to use dimethylacetamide, hexamethylphosphoramide, N-methylpyrrolidone, tetrahydrofuran, hexafluoroisopropanol, and dimethylsulfoxide will be.

In the present invention, the temperature at which the meta-aramid polymer is formed may be 0 to 70 ° C, and the meta-aramid polymer may be selected from the group consisting of poly (metaphenylene isophthalamide), poly (m-benzamide) (M, m'-phenylene benzamide), and poly (1,6-naphthylene isophthalamide).

Further, the meta-aramid polymer is subjected to a neutralization step. It is possible to neutralize hydrochloric acid (HCl) which is a by-product of the polymerized poly (meta-phenylene isophthalamide) by reacting metaphenylenediamine with isophthaloyl chloride. This is for the stability of the polymer composition.

A basic compound such as calcium hydroxide (Ca (OH) ₂ ) or lithium hydroxide (LiOH) may be added for the neutralization of hydrochloric acid produced by the reaction of metaphenylenediamine and isophthaloyl chloride, same.

[Reaction Scheme 2]

HCl + Ca (OH) _{2 -} > CaCl ₂ + 2H ₂ O

In the neutralization step, the amount added in the step of adding calcium hydroxide to neutralize hydrochloric acid, which is a by-product of the polymerization step, should be controlled according to the amount of metaphenylenediamine or isophthaloyl chloride used, and the amount of metaphenylenediamine or isophthaloyl It is desirable to add an amount equal to or 10% greater than the molar ratio of chloride.

On the other hand, the composite fiber of the present invention may mean that the first composition and the second composition are not mixed with each other, and that the respective components are separately formed in the fibers. The first meta-aramid component and the second meta- It is possible to produce a composite fiber capable of shrinking due to a difference in diffusion coefficient between the first solvent and the second solvent.

The diffusion coefficient of the solvent in the present invention means a value that defines the diffusion rate and means different values depending on the molecular weight and temperature conditions of the material to be diffused. In the present invention, can do.

Next, the step of composite spinning the first composition and the second composition, which is the step (2), to produce a conjugate fiber will be described.

According to a preferred embodiment of the present invention, the composite radiation may preferably be dry radiation. The dry spinning of the present invention is characterized in that the first and second compositions 12,13 discharged from the spinneret 11 of the spinneret 10 of Figure 1 are delivered to the first and second The temperature of the hot gas may be in the range of 60 to 250 ° C. If the temperature of the hot gas is lower than 60 ° C., there may be a problem in the extraction of the solvent into the apparatus And if it exceeds 250 DEG C, it may be difficult to vaporize all the solvents and selectively vaporize them.

Specifically, the spinning nozzle 11 and the spinneret (not shown) can use a spinning nozzle and spinneret which are generally used depending on the kind of a desired composite fiber. Thereafter, the composite fiber emitted from the spinning nozzle 11 is allowed to fall freely in the spinneret. At this time, the high temperature inert gas supplied to the inside of the spinneret evaporates from the surface of the discharged first and second compositions, And the degree of removal of the solvent to be removed from the inside of the composition is changed, and as a result, the shrinkage characteristics can be expressed. Nitrogen gas is usually the most common, though there may be some types of gas used at this time as the hot inert gas used.

The degree of removal of the solvent is determined by the permeability and selectivity of the solvent and the permeability of the solvent vaporized by the high temperature inert gas means the rate of permeation through the separator. Thus, the permeability is a function of the physicochemical properties of the first and second composition surfaces, the nature (size, shape and polarity) of the permeate gas, and the interaction of the separator and gas. The composition properties of the first and second compositions and the nature of the vaporized solvent determine the diffusion characteristics of the solvent through the composition surfaces of the first and second compositions. The permeability (P) of the vaporized solvent to the surface of the composition of the first and second compositions can be represented by the formula (1) as the product of adsorption (or solubility, S) and diffusion coefficient (D).

[Chemical Formula 1]

P = SD

Here, adsorption (or solubility) is a measure of the equilibrium adsorption amount (or solubility) of a gas on a surface at a given pressure and temperature, and the diffusion coefficient is a measure of how quickly the gas passes through the membrane. The adsorption amount and diffusion coefficient are factors influenced by the molecular weight of the gas. This means that the individual solvents capable of dissolving the meta-aramid polymer have different molecular weights and therefore have different values of diffusion coefficient and adsorption amount.

According to the above-described principle, when the composite solution spinning having a bi-component (or multi-component) cross-sectional configuration in which a heterogeneous solvent is applied to the same meta-aramid polymer is advanced, the solvent removal efficiency differs for each component under the same spinning- The degree of the natural orientation of the molecular chains changes in the process of free fall in the radiation tube due to the difference in the volume reduction rate of the solvent occupying the inside of the first and second compositions discharged from the first and second compositions, Which imparts different shrinkage properties to the product during the stretching / heat treatment process, making it possible to manufacture products with elastic properties (see FIG. 1).

Thus, in the present invention, a difference in solvent removal rate occurs between the first and second meta-aramid polymerization initiators in the spinning out of the first and second compositions containing different first and second solvents having different diffusion coefficients The difference in the volume of the solvent removed from the fibers to be discharged may cause a difference in the natural orientation of the molecular chains.

Meanwhile, the present invention may further include the following additional steps after the spinning step. In general, the meta-aramid polymer may contain a salt, and the meta-aramid polymer solution containing the salt is extruded through the dry spinning process at elevated temperature, and then the fibers are sent downward through a column having a gaseous medium at an elevated temperature , And a portion of the solvent is evaporated. In general, subsequent treatment steps may be necessary to remove by-products and solvents generated by the residue during the meta-aramid polymerization process.

Wherein the preliminary conditioning step comprises adding to the spinning fiber at least one solvent selected from dimethylacetamide, hexamethylphosphoramide, N-methylpyrrolidone, tetrahydrofuran, hexafluoroisopropanol, and dimethylsulfoxide, and The solution is contacted with a preconditioning solution having a concentration of any one of salt selected from lithium chloride (LiCl), calcium chloride, preferably the solution may comprise from 4 to 40% by weight of solvent, 15% by weight. And in general the temperature of the pre-conditioning solution is significantly lower than the temperature of the fibers exiting the spinneret, and preferably the temperature of the pre-conditioning solution is 0 to 10 ° C. The pre-conditioning solution can further reduce the temperature of the fibers and create a polymer-rich phase at the surface of the fibers, which can extend the length of the fiber to several times its unit length to the desired diameter If the fibers are pricked in the stretching process, the individual fibers tend to break. To prevent this, in current practice, still wet fibers from the pre-conditioning process are placed in the tub for a period of time that can be from hours to days. The fibers may then be removed from the barrel and washed to remove the solvent and simultaneously stretched to a desired extent on a series of rolls in a number of aqueous baths. The bundle of fibers or filaments may then be further subjected to a conditioning step in which the fibers are conditioned prior to the subsequent stretching step to prevent breakage of the individual filaments in this continuous process. The additional conditioning step is most commonly the spraying of the conditioning solution onto the continuously traveling fibers.

The conditioning solution preferably comprises, at elevated temperature, at least one solvent selected from dimethylacetamide, hexamethylphosphoramide, N-methylpyrrolidone, tetrahydrofuran, hexafluoroisopropanol, and dimethylsulfoxide, (LiCl), calcium chloride, and the like. In particular, the conditioning solution may have a higher concentration of solvent than the pre-conditioning solution, and may have a temperature higher than the pre-conditioning solution temperature, and preferably the conditioning solution is in the solvent and salt, based on the total weight of the aqueous conditioning solution , The solvent may include 2 to 20 wt% and the salt may include 2 to 10 wt%, and the conditioning temperature may be 25 to 110 째 C.

Further, the present invention may further include a spinning process and a heat treatment process after spinning in a different form from the above. The spinning process of the present invention is a spinning process in which the first composition and the second composition are spinned at a spinning ratio of 30:70 to 70:30 at 230 to 290 ° C at a spinning speed of 800 to 1500 mpm into side by side type fibers And the stretching process may be preferably a process of stretching the spun fibers at a stretching ratio of 1.5 to 4.5 at 40 to 120 캜, preferably in a warm bath. The heat treatment may be performed in a dry heat process by heat treating the drawn fibers at 250 to 370 ° C. In the present invention, shrinkage difference occurs after passing through the stretching and heat treatment processes, and natural omega-shaped crimps are formed and the bulky property is expressed.

According to the method for producing a meta-aramid composite fiber, the meta-aramid composite fiber produced by the method of the present invention includes two or more meta-aramid components having different heat shrinkage ratios, Thereby making it possible to manufacture a product imparted with a bulky property.

According to another aspect of the present invention, there is provided a meta-aramid composite fiber having two or more meta-aramid components having different thermal contraction ratios and having shrinkage properties, The difference in the heat shrinkage ratio of the two or more meta-aramid components may be in the range of 1000 to 50,000 ppm. If the difference in the heat shrinkage ratio of the meta-aramid component is less than 1000 ppm, there may be a problem in winding- There is a problem that the phase separation due to shrinkage is separated.

In addition, the meta-aramid component may include one copolymerized with an aromatic diamine and an aromatic diacid chloride. Specifically, the aromatic diamine may be generally used as a metaphenylenediamine, and the aromatic diacid chloride may be an isophthaloyl chloride. Can be polymerized by reacting as a raw material in accordance with the following reaction formula (1).

 [Reaction Scheme 1]

The polymerization process may be carried out by stirring the m-phenylenediamine and isophthaloyl chloride in an amide-based solvent to form a polymethenylene isophthaloyl chloride by a polymerization reaction. The m-phenylenediamine and isophthaloyl chloride are reacted at a similar molar ratio And more preferably, 5 to 15 parts by weight of metaphenylenediamine and 10 to 30 parts by weight of isophthaloyl chloride are mixed and polymerized in 100 parts by weight of the amide solvent.

On the other hand, the composite fiber of the present invention may mean that the first composition and the second composition are not mixed with each other, and that the respective compositions are separately formed in the fibers. Specifically, the conjugate fiber of the present invention may be of the side by side type, and is not particularly limited thereto. It is preferable that the conjugate fiber is in the form of a composite fiber including the first composition and the second composition separately.

2 is a cross-sectional view of a side by side type composite fiber according to a preferred embodiment of the present invention.

According to a preferred embodiment of the present invention, the fineness of the meta-aramid conjugate fiber may be 1 to 10 denier, and if the fineness is less than 1 denier, there may be a problem with the elasticity of the meta- If it exceeds 10 denier, it may be difficult to extract the solvent present therein.

As a result, the meta-aramid conjugated fibers provided by the present invention impart different shrinkage properties, making it possible to manufacture a product having a bulky property.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

[ Example ]

Example  One

(1) Production of first composition

To 100 parts by weight of tetrahydrofuran (diffusion coefficient: 0.093595611), 6 parts by weight of metaphenylenediamine and 20 parts by weight of isophthaloyl chloride were mixed to prepare a polymer. After the above-mentioned polymerization step, 8 parts by weight of calcium hydroxide was added to 100 parts by weight of dimethylacetamide, and the neutralization step was carried out. After the neutralization, a first composition was prepared by a defoaming process.

(2) Production of second composition

Was prepared in the same manner as in the first composition except that N-methylpyrrolidone (diffusion coefficient: 0.071621046) was used.

(3) Manufacture of meta-aramid composite fibers

The first composition and the second composition prepared above were put into a hollow side by side at a spinning rate of 1000 mPm at a spinning temperature of 260 캜 at a weight ratio of 50:50, The drawn fibers were immediately advanced to the washing process after the spinning fibers were drawn at a draw ratio of 4.0 at 90 ° C and then the 90 ° C water was passed through the drawn fiber surface To wash and remove residual solvent and salts from the fibers. After washing for 4 seconds, the washed fibers exited the washing process and proceeded to the drying step immediately, and heat treated at 350 ° C. to prepare a conjugate fiber having a uniformity of 2.2 and a single fiber fineness of 2 denier.

Comparative Example  One

Was prepared in the same manner as in Example 1 except that the first composition and the second composition were prepared using a solvent having the same diffusion coefficient.

Experimental Example  One

The fibers prepared in Example 1 and Comparative Example 1 were evaluated in the following 1 to 2.

1. Measurement of heat shrinkage difference

; ASTM-E881.

2. Measurement of River and Shinto

The tensile strength, the friction strength, and the flexural strength of the fibers are generally indicated by the tensile strength. Gangshin-do varies depending on the temperature and humidity of the atmosphere and moisture absorption of the fiber, so it is a general rule to measure it in the standard state (20 ℃ and 65% RH) of the atmosphere. As a measurement method, a constant descent type is applied. Constant decoration is to extend the sample at a constant speed.

The elongation is the percentage of the difference between the initial length of the fiber and the stretched length of the fiber just before it is broken. The test equipment used is VIBROSKOP.

Heat shrinkage difference burglar
(g / de) Shindo
(%) The first meta-aramid component The second meta-aramid component Difference Example 1 12000 48000 36000 4.2 38.2 Comparative Example 1 42000 42050 50 4.0 36.5

As a result of the measurement, it can be seen that the difference in heat shrinkage ratio in Example 1 is larger than that in Comparative Example 1. [

10: Radiation tube 11: Spin nozzle
12, 13: first and second composition 14: hot gas
15, 16: a first solvent and a second solvent

Claims (12)

(1) a first composition comprising a first meta-aramid polymer and a first solvent; And a second composition comprising a second meta-aramid polymer and a second solvent having a diffusion coefficient different from that of the first solvent; And
(2) composite spinning the first composition and the second composition to prepare a conjugate fiber,
Wherein the composite spinning is dry spinning and the dry spinning is carried out such that the composite fibers discharged from the spinning nozzle are differentially removed from the first solvent and the second solvent through the hot gas in the spinneret, ≪ / RTI >
The method according to claim 1,
Wherein the first meta-aramid polymer and the second meta-aramid polymer comprise a copolymer comprising an aromatic diamine and an aromatic diacid chloride.
delete delete The method according to claim 1,
Wherein the hot gas is 60 to 250 ° C.
The method according to claim 1,
Wherein the meta-aramid composite fiber is a side by side type fiber.
delete delete delete delete delete delete

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