KR102205529B1 - Lyocell Fiber - Google Patents

Abstract

The present invention relates to a lyocell fiber, and more particularly, by controlling the cross-sectional shape of the monofilament contained in the lyocell fiber to improve the specific surface area of the fiber, even when using a small amount of the same level compared to the conventional lyocell fiber It relates to a lyocell fiber capable of exhibiting the above physical properties.

Description

Lyocell Fiber

The present invention relates to a lyocell fiber.

Fiber refers to a natural or artificial linear object that is flexible and thin when viewed in shape, and has a large ratio of length to thickness. When these fibers are classified in terms of their shape, they are divided into long fibers, semi-long fibers, and short fibers, and when classified in terms of raw materials, they are divided into natural fibers and artificial fibers.

Fibers have been closely related to human life since before, and natural fibers such as cotton, hemp, wool, and silk were used as the main raw material for cloth. After the Industrial Revolution, with the development of science and technology, textiles have expanded not only as a covering material, but also for industrial use.In order to meet the rapidly increasing demand for textiles with the development of culture and population, the field of artificial fibers has become a new textile material. It was pioneered.

Among these artificial fibers, recycled fibers are not only excellent to the touch and fit, but also have a much faster moisture absorption and discharge ability than cotton, and thus have been widely used as raw materials for coatings. In particular, among these regenerated fibers, rayon fibers have excellent gloss and color development properties, and can implement a touch equivalent to that of natural fibers, and have been widely used in the past because they are recognized as harmless materials. However, this rayon fiber had the characteristics of a material that was easily shrunken and wrinkled, and the manufacturing process was complicated and many chemicals were used in the process of melting wood pulp, which caused environmental problems in the work and environmental pollution in the process of wastewater treatment. Had a problem that caused it.

Accordingly, research has been conducted on fibers that are harmless to the environment and human body and are superior in physical properties to other conventional fibers, and recently, lyocell fibers manufactured from natural pulp and amine oxide hydrates have been introduced. These lyocell fibers have superior tensile properties and fiber properties such as tactile feel compared to existing recycled fibers, but do not generate any contaminants in the production process, and the amine oxide-based solvent used is recyclable and biodegradable upon disposal. As an eco-friendly fiber, it is used in various fields.

However, currently, only products with a circular cross-section of lyocell fiber can be produced, but it is expected that various physical properties can be exhibited according to the cross-sectional shape of lyocell fiber. Research is required.

The present invention is to provide a lyocell fiber having a large specific surface area.

Accordingly, as a first preferred embodiment of the present invention, a lyocell multi prepared by spinning a lyocell spinning dope containing a cellulose pulp and an N-methylmorpholine-N-oxide (NMMO) aqueous solution. Including a filament, wherein the multifilament is made of a monofilament whose cross section is a deformed cross section, and the deformed cross section includes a plurality of protrusions, and the plurality of protrusions are formed of a first imaginary circle and a first imaginary circle. Provides a lyocell fiber, characterized in that it is in contact with a virtual second circle contained therein, but is formed integrally with the virtual second circle as a center, and its end has a shape in contact with the virtual first circle. do.

The lyocell spinning dope according to the embodiment is 6 to 16% by weight of cellulose pulp; And 84 to 94% by weight of an N-methylmorpholine-N-oxide aqueous solution.

The cellulose pulp according to the above embodiment may have an alpha-cellulose content of 85 to 97% by weight and a polymerization degree (DPw) of 600 to 1700.

The lyocell fiber according to the above embodiment may have a space occupancy of 150 to 400%, defined by Equation 1 below.

<Equation 1>

Space occupancy (%) = (area of the first virtual circle/cross-sectional area of monofilament included in the lyocell fiber) × 100

The first virtual circle according to the above embodiment may have a radius of 8 to 30 μm.

The virtual second circle according to the above embodiment may have a radius of 3 to 12 μm.

According to the present invention, it is possible to provide a lyocell fiber having a large specific surface area, so when it is used for reinforcing materials in clothing, construction or automobile fields, it is possible to exhibit physical properties equal to or higher than the conventional lyocell fiber even if a smaller amount is used. It works.

1 is a schematic cross-sectional view of a monofilament included in a lyocell fiber according to an embodiment of the present invention.
Figure 2 is a photograph showing a cross-section of a lyocell fiber manufactured according to an embodiment of the present invention, each (a) is Example 1, (b) is Example 2, and (b) is manufactured according to Example 3 This is a cross-sectional picture of the lyocell fiber.

Hereinafter, the present invention will be described in more detail.

The present invention includes a lyocell multifilament prepared by spinning a lyocell spinning dope containing a cellulose pulp and an N-methylmorpholine-N-oxide (NMMO) aqueous solution, wherein the multifilament Is made of a monofilament whose cross section is a deformed cross section, the deformed section includes a plurality of protrusions, and the plurality of protrusions are a virtual first circle and a virtual second included in the virtual first circle. It is in contact with a circle, but is formed integrally with the virtual second circle as a center, and the end thereof relates to a lyocell fiber having a shape in contact with the virtual first circle.

[Multi lobal]

In the present invention, the deformed cross-section refers to a shape including a plurality of protrusions, and specifically, as shown in FIG. 1, refers to a cross-section having a plurality of protrusions formed integrally with one central portion 1 as the center.

Specifically, the deformed cross section is within the range of the virtual first circle 11 connecting the end points of each of the plurality of protrusions and the virtual second circle 12 included in the virtual first circle 11 You can define its size and shape in. At this time, the virtual first circle (11) and the virtual second circle (12) is a circle whose radius is larger than that of the virtual second circle (12). The furnace may have the same center, but the center may not be the same.

The deformed cross-section includes a plurality of protrusions, and the plurality of protrusions are formed integrally with the central portion 1 overlapping the virtual second circle 12, but the ends 5 of each protrusion are The concave portion 4 in contact with the first circle 11 and formed between the protrusions has a shape in contact with the virtual second circle 12.

In the present invention, in terms of maximizing the specific surface area of the lyocell fiber, the modified cross section may include three protrusions.

The virtual first circle may have a radius of 8 to 30 μm, and the virtual second circle may have a radius of 3 to 12 μm.

When the radius of the virtual first circle is 8 μm or more, a deformed cross-sectional shape can be realized, and when it is 30 μm or less, a monofilament having a fineness suitable as a textile product can be formed. In addition, when the radius of the virtual second circle is 3 μm or more, it is possible to implement a deformed cross-section, and when it is 12 μm or less, a monofilament having a fineness suitable as a textile product can be formed.

The monofilament included in the lyocell fiber according to the present invention may have a release cross-section as described above, and the lyocell fiber may have a space occupancy of 150 to 400%, defined by the following formula 1.

<Equation 1>

Space occupancy (%) = (area of the first virtual circle/cross-sectional area of monofilament included in the lyocell fiber) × 100

Here, the space occupancy ratio means the ratio of the space that the monofilament substantially occupies in the fiber due to the protrusion of the deformed cross section. That is, if the cross-section of the monofilament included in the lyocell fiber is a circular cross-section, the cross-sectional area of the actual monofilament and the area of the virtual first circle are the same, and thus the space occupancy defined as above is 100%, but In the case of a fiber having a deformed cross section, the actual area occupied by the fiber increases due to the protrusion. Therefore, it can be seen that as the space occupancy increases, the specific surface area of the fiber increases.

The lyocell fiber of the present invention has a space occupancy of 150 to 400%, preferably 300 to 400, in terms of excellent properties such as puffiness, interfacial adhesion, and quick-drying characteristics due to the increased specific surface area. To have %.

On the other hand, the present invention (S1) spinning a lyocell spinning dope comprising a cellulose pulp and N-methylmorpholine-N-oxide (N-methylmorpholine-N-oxide; NMMO) aqueous solution; (S2) coagulating the lyocell spinning dope spun in the (S1) step to obtain a lyocell multifilament; (S3) washing the lyocell multifilament obtained in step (S2) with water; And (S4) subjecting the lyocell multifilament washed with water in step (S3) to an emulsion treatment, wherein the multifilament is made of monofilament whose cross section is a deformed cross section, and The deformed cross section includes a plurality of protrusions, and the plurality of protrusions are in contact with a virtual first circle and a virtual second circle included in the virtual first circle, with the virtual second circle as a center. Thus, it is formed integrally, and the end thereof relates to a method of manufacturing a lyocell fiber, characterized in that it has a shape in contact with the virtual first circle.

[Step (S1)]

Step (S1) is a step of spinning a lyocell spinning dope containing an aqueous solution of cellulose pulp and N-methylmorpholine-N-oxide (NMMO).

The lyocell spinning dope is 6 to 16% by weight of cellulose pulp; And 84 to 94% by weight of an N-methylmorpholine-N-oxide aqueous solution, and the cellulose pulp may have an alpha-cellulose content of 85 to 97% by weight, and a polymerization degree (DPw) of 600 to 1700. have.

In the lyocell spinning dope, if the content of cellulose pulp is less than 6% by weight, it may be difficult to implement fibrous characteristics, and if it is more than 16% by weight, it may be difficult to dissolve in an aqueous solution.

In addition, in the lyocell spinning dope, if the content of the N-methylmorpholine-N-oxide aqueous solution is less than 84% by weight, it is not preferable because the dissolution viscosity is large, and if it exceeds 94% by weight, the spinning viscosity is significantly lowered in the spinning step. It can be difficult to produce uniform fibers.

The weight ratio of N-methylmorpholine-N-oxide and water in the N-methylmorpholine-N-oxide aqueous solution may be 93:7 to 85:15. When the weight ratio of the N-methylmorpholine-N-oxide and water is more than 93:7, the dissolution temperature increases, and decomposition of cellulose may occur when dissolving cellulose, and when the weight ratio is less than 85:15, the dissolution performance of the solvent It can be degraded, making it difficult to dissolve the cellulose.

It is discharged from the spinning nozzle of the spinneret using the spinning dope described above. At this time, the spinneret serves to discharge the spinning dope on the filament into the coagulation solution in the coagulation tank through the air gap section. The step of discharging the spinning dope from the spinneret may be performed under a spinning temperature of 80 to 130°C.

The spinneret may be a spinneret in which a plurality of the unit holes are formed when a plurality of holes are set as one unit hole in the shape of the holding hole. In this case, the number of holes included in the unit hole may be the same as the number of protrusions of the deformed cross section. For example, in order to manufacture a lyocell fiber including a monofilament having a deformed cross section including three protrusions, the number of holes included in the unit hole may be three.

[Step (S2)]

Step (S2) is a step of obtaining a lyocell multifilament by coagulating the lyocell spinning dope spun in step (S1), and the solidification of the step (S2) is air quenching in which cooling air is supplied to the spinning dope to solidify. The first coagulation step by (Q/A); And a second coagulation step of immersing the first coagulated spinning dope in a coagulation solution to coagulate.

In the step (S1), after the spinning dope is discharged through the spinneret, it may be passed through the spinneret and the air gap section of the space between the coagulation tank. In the air gap section, cooling air is supplied from the inside of the cage to the outside from the air cooling unit located inside the donut-shaped cage, and the cooling air can be first solidified by air quenching that supplies the cooling air to the spinning dope.

At this time, the factors that affect the physical properties of the lyocell multifilament obtained in step (S2) are the temperature and wind speed of the cooling air in the air gap section, and the solidification in step (S2) is at a temperature of 4-15℃ and 5 ~ It may be to solidify by supplying cooling air having a wind speed of 50 m/s to the spinning dope.

If the temperature of the cooling air during the first solidification is less than 4℃, the surface of the crest cools, the cross section of the lyocell multifilament becomes uneven and the spinning processability is not good, and if it exceeds 15℃, the first solidification by the cooling air is insufficient. So that the spinning fairness is not good.

In addition, if the wind speed of the cooling air is less than 5m/s during the primary coagulation, the primary coagulation by the cooling air is insufficient, resulting in poor spinning processability, resulting in thread trimming.If it exceeds 50m/s, the spinning dope discharged from the detention center As it is shaken by air, the spinning process becomes poor.

After the first coagulation by air quenching, the spinning dope is supplied to the coagulation tank containing the coagulation solution, so that the secondary coagulation can proceed. On the other hand, for proper secondary coagulation, the temperature of the coagulation solution may be 30°C or less. This is to ensure that the secondary solidification temperature is not higher than necessary, so that the solidification rate is properly maintained. Here, the coagulation solution is not particularly limited since it can be prepared and used in a conventional composition in the technical field to which the present invention belongs.

[Step (S3)]

Step (S3) is a step of washing the lyocell multifilament obtained in step (S2) with water.

Specifically, after the lyocell multifilament obtained in step (S2) is introduced into the pulling roller, it can be washed with water by introducing it into a water washing bath.

In the washing step of the filament, in consideration of the ease of recovery and reuse of the solvent after washing with water, a washing solution having a temperature of 0 to 100°C may be used, and water may be used as the washing solution, and other additions as necessary Ingredients may be further included.

[Step (S4)]

Step (S4) is a step of treating the lyocell multifilament washed with water in step (S3) with an emulsion, and may be dried after the emulsion treatment.

The emulsion treatment takes a form in which the multifilament is completely immersed in the emulsion and is buried, and the amount of the emulsion deposited on the filament is kept constant by the weaving rollers attached to the entry roll and the discharge roll of the emulsion treatment device. The emulsion serves to reduce friction generated when the filament contacts the drying roller, the guide, and the crimp step.

The lyocell fiber as described above is biodegradable, so it is environmentally friendly.

In addition, the lyocell fiber has a monofilament having a shape of a deformed cross-section including a plurality of protrusions, and the specific surface area is large, so that even if a small amount is used compared to the conventional circular cross-section lyocell fiber, lyocell fiber having the same or more physical properties is used. Can be manufactured.

In particular, since the lyocell fiber according to the present invention has a large non-target area, when used as a reinforcing material in the field of clothing, construction, or automobiles, the effect of exhibiting physical properties equal to or higher than that of the conventional lyocell fiber is used. have.

When the lyocell fiber according to the present invention is used for clothing, due to its large specific surface area, it exhibits excellent moisture absorption and quick-drying.Therefore, even if sweat is discharged, there is no wound around the body, so that the skin is always in a comfortable state to reduce discomfort. have. In addition, the cooling speed is excellent, and if sweat is continuously discharged, rapid cooling can be maintained continuously. Specifically, the application range for clothing may include outdoor, sports, T-shirt, golf, men's and women's clothing, functional inner wear, hats, sports socks, underwear, and the like.

When the lyocell fiber according to the present invention is used as a reinforcing material, the reinforcing function increases as the contact area with the material to be reinforced increases, and it can be applied to MRG (Mechanical Rubber Good) such as tire cord and hose reinforcement, cement reinforcement, and automobile interior materials. I can.

Hereinafter, the present invention will be described in more detail through examples. These examples are for illustrative purposes only, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples.

Example 1

A cellulose pulp with a degree of polymerization (DPw) of 820 and an alpha cellulose content of 93.9% is mixed with a NMMO/H ₂ 0 mixed solvent (weight ratio of 90/10) with a propyl gallate content of 0.01% by weight, and spinning for the production of lyocell fibers having a concentration of 12% by weight The dope was prepared.

First, the spinning dope was maintained at a spinning temperature of 110°C in a spinning nozzle of a spinneret in which a plurality of unit holes including three holes were formed, and the discharge amount and spinning speed of the spinning dope so that the single fineness of the filament was 3.37 denier. Spinning was performed by controlling. The spinning dope on the filament discharged from the spinning nozzle was supplied to the coagulation solution in the coagulation tank through the air gap section. At this time, in the air gap section, the cooling air first solidifies the spinning dope at a temperature of 8°C and a wind speed of 10 m/s.

The coagulation solution was used at a temperature of 25°C and a concentration of 85% by weight of water and 15% by weight of NMMO.

At this time, the concentration of the coagulation solution was continuously monitored using a sensor and a refractometer.

The filament stretched in the air layer through the traction roller is washed by the water sprayed by the water washing device to remove the remaining NMMO, and the oil agent is evenly applied to the filament, and then squeezed again so that the oil content of the filament is 0.2 % Was maintained and dried at 150° C. on a drying roller to prepare a lyocell fiber including multifilament made of monofilament having a deformed cross section including three protrusions.

Example 2

In the same manner as in Example 1, except that the filament had a single fineness of 3.58 denier, a lyocell fiber including multifilament made of monofilament having a deformed cross section including three protrusions was prepared.

Example 3

In the same manner as in Example 1, except that the single fineness of the filament was made to be 14.82 denier, a lyocell fiber including multifilament made of monofilament having a deformed cross section including three protrusions was prepared.

Comparative Example 1

Monofilament having a circular cross section in the same manner as in Example 1, except that one circular hole was used as a unit hole, and a spinneret having a plurality of unit holes was used, and the single fineness of the filament was 1.73 denier. A lyocell fiber containing multifilament was prepared.

Comparative Example 2

A lyocell fiber including multifilament made of monofilament having a circular cross section was prepared in the same manner as in Comparative Example 1, except that the filament had a single fineness of 2.97 denier.

For the lyocell fibers prepared in Examples and Comparative Examples, the cross-sectional shape, fineness, and space occupancy of the monofilament included in the lyocell fibers were measured and calculated by the following method, and the results are shown in Table 1 below. .

(1) Cross-sectional shape of monofilament included in lyocell fiber

A small amount of fiber bundles were sampled, rolled together with black cotton, thinned, and inserted into a hole in a plate that could cut the cross section, and then cut with a razor blade so that the cross section was not pushed.

The cross-section was enlarged (× 200) using an optical microscope (BX51, manufactured by Olympus), and the image was saved with a digital camera. For the cross-sectional image of the fiber, a cross-section to be obtained was designated using the Olympus soft imaging solution program and the radius and area were analyzed.

(2) Fineness

The fineness of the lyocell fibers was calculated by using Equation 2 below using the monofilament cross-sectional area of the actual lyocell fibers obtained through cross-sectional analysis and the density of the lyocell fibers.

The density of lyocell fiber = 1.49 g/cm ³

<Equation 2>

Fineness (De) = [Monofilament cross-sectional area of lyocell fiber (㎛ ² ) × density of lyocell fiber (g/cm ³ ) × 9000 (m)]/1000000

(3) space occupancy

The space occupancy rate of the lyocell fiber was calculated by the following equation 1.

<Equation 1>

Space occupancy (%) = (area of the first virtual circle/cross-sectional area of monofilament included in the lyocell fiber) × 100

Cross-sectional shape of monofilament included in lyocell fiber
Fineness
(De)

L1/L2
space
Share
(%) Fictitious first circle
radius
(L1,㎛)
Virtual second circle
radius
(L2, ㎛)
Fictitious first circle
Area (㎛ ² )
Real lyocell fiber monofilament cross-sectional area (㎛ ² ) Example 1 16.75 3.87 881 251.6 3.37 4.33 350 Example 2 11.44 6.16 411 266.6 3.58 1.86 154 Example 3 27.78 11.61 2423 1105 14.82 2.40 219 Comparative Example 1 6.4 6.4 129 129 1.73 One 100 Comparative Example 2 8.4 8.4 222 222 2.97 One 100

As shown in Table 1, the lyocell fibers of Examples 1 to 3 made of monofilaments having a deformed cross section occupy space compared to the lyocell fibers of Comparative Examples 1 and 2 made of monofilaments having a circular cross section. It turned out to be great. At this time, the cross-sections of the lyocell fibers of Examples 1 to 3 are as shown in Figure 2 (a) to (c), respectively.

From these results, it can be seen that the lyocell fibers of Examples 1 to 3 have a large specific surface area, and can be widely applied to fields requiring a fiber having a large specific surface area.

As the specific parts of the present invention have been described in detail above, it will be apparent to those of ordinary skill in the art that these specific descriptions are only preferred embodiments, and the scope of the present invention is not limited thereby. will be. Accordingly, it will be said that the substantial scope of the present invention is defined by the appended claims and their equivalents.

1: center, 2: protrusion, 3: major axis of protrusion, 4: concave part of protrusion, 5: end of protrusion
11: virtual first circle, 12: virtual second circle

Claims (7)

Including a lyocell multifilament prepared by spinning a lyocell spinning dope containing a cellulose pulp and N-methylmorpholine-N-oxide (NMMO) aqueous solution,
The multifilament is made of a monofilament whose cross section is a shaped cross section,
The modified cross section includes a plurality of protrusions,
The plurality of protrusions are in contact with a virtual first circle and a virtual second circle included in the virtual first circle, but are integrally formed with the virtual second circle as a center, and the ends thereof are the virtual It has a shape in contact with the first circle of,
The imaginary first circle has a radius of 16.75 ~ 30㎛, the imaginary second circle is a lyocell fiber, characterized in that the radius is 3 ~ 3.87㎛.
The method of claim 1,
The lyocell spinning dope is 6 to 16% by weight of cellulose pulp; And 84 to 94% by weight of an N-methylmorpholine-N-oxide aqueous solution.
The method of claim 2,
The cellulose pulp has an alpha-cellulose content of 85 to 97% by weight, and a degree of polymerization (DPw) of 600 to 1700.
The method of claim 1,
The lyocell fiber is a lyocell fiber, characterized in that the space occupancy rate defined by the following equation 1 is 150 to 400%:
<Equation 1>
Space occupancy (%) = (area of the first virtual circle/cross-sectional area of monofilament included in the lyocell fiber) × 100
delete delete The method of claim 1,
Lyocell fiber, characterized in that the center of the virtual first circle and the second virtual circle are the same.

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