KR101430714B1 - Dope for spinning lyocell, method for preparing lyocell filament fiber, and lyocell filament fiber prepared therefrom - Google Patents

Abstract

The present invention relates to a lyocell spinning dope comprising an aqueous solution of cotton linter pulp and N-methylmorpholine-N-oxide (NMMO), a process for producing a lyocell filament fiber using the same And a lyocell filament fiber produced therefrom. By using such a lyocell spinning dope, a low degree of orientation and fibrillation can be realized without any additional process, and a high elongation can be easily applied to a high-grade garment fiber Lyocell fibers.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a lyocell filament fiber, and a method for producing the lyocell filament fiber using the lyocell fiber filament fiber. BACKGROUND ART [0002]

The present invention relates to a lyocell spinning dope, a method for producing a lyocell filament fiber using the same, and a lyocell filament fiber produced from the dyestuff. More particularly, the present invention relates to a lyocell disposable dope capable of providing a lyocell fiber which can be applied as a high-grade garment fiber by exhibiting low elongation and high elongation with a degree of fibrillation without further processing, a lyocell filament And to a lyocell filament fiber produced therefrom.

Fiber means a natural or artificial linear object that is flexible and thin when viewed in shape and has a large length to thickness ratio. These fibers are divided into long fibers, quasi-long fibers, and short fibers. The fibers are divided into natural fibers and man-made fibers.

Previously, fibers had a close relationship with human life, and natural fibers such as cotton, hemp, wool, and silk fiber were used as the main raw materials for the fabrics. Since the industrial revolution, the textile has expanded its application not only to the covering materials but also to the industrial use. In order to meet the rapidly increasing demand of the fiber with the development of the culture and the population, It was pioneered.

Among these man-made fibers, regenerated fibers are not only excellent in feel and fit, but also have moisture absorbing and discharging ability much faster than cotton, and thus they have been widely used as raw materials for coating. Particularly, among these regenerated fibers, rayon fibers have excellent gloss and coloring property and can not only realize a feeling equivalent to that of natural fibers but also have been widely used in the past as they are recognized as harmless materials to human body. However, these rayon fibers have characteristics of shrinkage and creasing. Since the manufacturing process is complicated and a lot of chemicals are used in the process of melting wood pulp and the like, environmental pollution And the like.

As a result, research has been conducted on fibers that are harmless to the environment and human body and have superior physical properties and superior to other conventional fibers. Recently, Lyocell fibers produced from natural pulp and amine oxide hydrates have been introduced. These lyocell fibers have excellent tensile properties and tactile properties as compared with conventional regenerated fibers, and do not generate any contaminants in the production process. The amine oxide-based solvent used is recyclable and biodegradable upon disposal , And are used in various fields as environmentally friendly fibers.

However, since the lyocell fiber has a high degree of orientation and a weak bonding force between the fibrils, excessive fibrils are formed on the surface of the lyocell fiber, and the surface texture of the fiber and the quality of the final product are deteriorated. In addition, in order to remove the fibrils from the lyocell, an additional step such as an acidic cellulase treatment is required, which complicates the manufacturing process, increases the production cost, reduces the weight of the fabric in the fibril removal process, .

Accordingly, there is a demand for development of a method capable of providing a high-quality fiber having a low degree of orientation and fibrillation by a simple process without adding a step for fibril removal while maintaining the characteristics of an environmentally friendly lyocell fiber.

The present invention is to provide a lyocell disposable dope capable of providing a lyocell fiber which can be applied as a high-grade garment fiber by exhibiting low elongation and high elongation with a degree of fibrillation without further processing.

The present invention also provides a method for producing Lyocell filament fibers using the Lyocell spinning dope.

The present invention also relates to a lyocell filament fiber produced from the lyocell firing dope.

The present invention provides a lyocell disposable dope comprising cotton linter pulp, water and N-methylmorpholine-N-oxide (NMMO).

Further, the present invention provides a method of manufacturing a spinning dope, comprising: discharging the spinning dope from a spinneret; Passing the discharged dope through a coagulation bath to solidify the filament; Washing the filament that has passed through the coagulation bath; And drying the washed filament. The present invention also provides a method for producing a lyocell filament fiber.

The present invention also provides a lyocell filament fiber produced from the spinning dope.

Hereinafter, a lyocell spinning dope, a method for producing a lyocell filament fiber, and a lyocell filament fiber according to a specific embodiment of the present invention will be described in detail.

According to one embodiment of the invention, a lyocell spinning dope comprising cotton linter pulp, water and N-methylmorpholine-N-oxide (NMMO) can be provided have.

The inventors of the present invention have found that when a lyocell fiber dope containing a cotton linter pulp is subjected to a specific manufacturing process as described below during the course of research to solve the high degree of orientation and the excessive fibrils formed on the fiber surface, , It was confirmed through experiments that the lyocell fiber having low degree of orientation and low fibrillation can be provided, and the invention was completed. The amount of fibril formed on the surface of the lyocell fiber or the degree of fibrillation thereof becomes very small by using the dyestuff for dyed lyocell so that the surface texture of the fiber and the quality of the final product can be improved , The additional manufacturing process can be omitted to simplify the manufacturing process and reduce the production cost. The lyocell fiber obtained by using the lyocell spinning dope can have a low initial elastic modulus and can be applied to high-grade clothing fibers such as lining and underwear of clothes.

Generally, the long side of a fiber that is separated from a seed in a cotton is called a lint, and the side where a secondly separated short fiber is called a linter. These liners usually have a fiber length of 3 to 5 mm and can be obtained from year-old cotton, which is advantageous in terms of raw material supply and demand.

Further, as described later, the cotton linter pulp may contain alpha-cellulose in a high content, for example, may contain at least 99% by weight of alpha-cellulose, and may exhibit a low degree of fibrillation, And it can be used as a fabric of high quality clothing products.

The lyocell spinning dope may comprise from 6 to 16% by weight of cotton linter pulp. If the content of the cotton linter pulp is less than 6% by weight, the fiber property can not be realized, and when it is more than 16% by weight, it may be difficult to dissolve in the aqueous liquid.

Also, the lyocell disinfecting dope may contain 84 to 94% by weight of an aqueous solution of N-methylmorpholine-N-oxide as a solvent component. When the content of the aqueous solution of N-methylmorpholine-N-oxide is less than 84% by weight, the solubility viscosity of the solution is undesirably increased. When the amount exceeds 94% by weight, the spinning viscosity is significantly lowered, Can be difficult.

The weight ratio of N-methylmorpholine-N-oxide and water in the N-methylmorpholine-N-oxide aqueous solution may be 91: 9 to 83:17. When the weight ratio of N-methylmorpholine-N-oxide and water is more than 91: 9, the dissolution temperature is high and cellulose may be decomposed upon dissolving cellulose. When the weight ratio is less than 83:17, And the dissolution of cellulose may be difficult.

The lyocell spinning dope is prepared by adding cotton linter pulp to an N-methylmorpholine-N-oxide aqueous solution containing N-methylmorpholine-N-oxide (NMMO) and water in a weight ratio of 90:10 to 50:50, Water, so that the weight ratio of N-methylmorpholine-N-oxide (NMMO): water is 93: 7 to 85:15 and the final content of pulp is 6 to 16% by weight, more preferably 10 to 14% And the like.

Meanwhile, according to another embodiment of the present invention, there is provided a method of preparing a lyocell disinfectant, comprising the steps of: discharging the lyocell disinfection dope from a spinneret; Passing the discharged dope through a coagulation bath to solidify the filament; Washing the filament that has passed through the coagulation bath; And drying the washed filament. The method for producing a lyocell filament fiber according to the present invention includes the steps of:

The present inventors have found that when a lyocell spinning dope containing cotton linter pulp is applied to a specific production method, it is possible to solve the problem of high degree of orientation, which is the greatest problem of the lyocell fiber, and excessive fibrils formed on the fiber surface, It was confirmed through experiment that the lyocell fiber could be provided and the invention was completed. According to this method for producing a lyocell filament fiber, it is not necessary to provide an additional step for removing fibrils because the amount of fibril formed on the surface or the degree of fibrillation of the lyocell fiber can be obtained, The process can be simplified and the production cost can be reduced. According to the production method, the surface of the fiber is excellent in the texture of the finished product and the quality of the final product is low, and a low initial elastic modulus is obtained, so that the lyocell filament fiber applicable to high-grade medical materials such as lining and underwear of clothes can be obtained.

The content of the diesel-assisted dope is already described above, but a detailed description thereof will be omitted.

The spinneret serves to discharge the filamentary filament through the air-gap and discharge it as a coagulating solution. The step of discharging the dosing dope from the spinneret can be performed at 80 to 130 ° C.

Further, after discharging the dosing dope, a step of passing the dosing dope through the air gap may be additionally performed. At this time, the air gap serves to pre-quench the liquid-phase dope by supplying air to the dope discharged from the spinneret. At this time, since the drawing viscosity of the dope is higher than that of a general dope, the temperature of the supplied air is preferably 5 to 30 ° C, 10-20 < 0 > C.

The air flow rate of the air applied in the air gap may be 10 to 300 m ³ / hr, preferably 30 to 100 m ³ / hr. When the air flow rate is excessively small, it is not preferable to cut off due to non-uniform stretching. When the air flow rate is excessively large, cutting due to cooling of the spinneret occurs, which is not preferable.

The dope discharged from the spinneret and selectively passing through the air gap is solidified in a coagulating bath to have a filament shape. At this time, the temperature of the coagulating bath may be 30 ° C or less. This is to ensure that the coagulation temperature is 30 ° C or lower because the temperature is not higher than necessary and the coagulation rate is appropriately maintained. Herein, the coagulating bath is not particularly limited as it can be manufactured and used in a conventional composition in the technical field to which the present invention belongs.

Meanwhile, the method for producing the lyocell filament fiber may include washing the filament that has passed through the coagulation bath, and drying the washed filament.

In the step of washing the filament that has passed through the coagulation bath, it may be used as a washing solution at a temperature of 0 to 100 ° C in consideration of the ease of recovery and reuse of the solvent after washing. Water may be used as the washing solution, Other additives may be further included if necessary.

The step of drying the washed filament comprises applying a tension of from 0.1 to 2 g / d, preferably from 0.2 to 0.5 g / d, to the filament at 80 to 200 ° C, preferably 100 to 150 ° C . The drying step may be a single step drying step or a multi step drying step in which the drying step is divided into different sections. The drying conditions of each step in the multi-stage drying step may be arbitrarily selected within the range of the tension and the temperature as required. In addition to the above conditions, ordinary conditions in the technical field of the present invention may be used.

FIG. 1 schematically shows an example of a spinning device which can be used for producing a lyocell filament fiber. Referring to FIG. 1, a typical configuration of a lyocell multifilament manufacturing apparatus includes a gear pump 11 for feeding a spinning stock solution at a constant pressure, a spinneret (not shown) for spinning the spinning solution supplied from the extruder in the form of fibers, (12), and a first coagulation bath (14) for coagulating the non-coagulated fibers (13) discharged from the spinneret and, if necessary, a second coagulation bath (15). The filaments passing through the coagulation baths 14 and 15 remove solvent or the like contained in the radiation dope or the like by water in the flushing device 17 by driving the drawing roller 16. Then, the filament that has passed through the flushing apparatus is dried in a drying apparatus 18 and then wound to obtain a final lyocell filament. However, such a spinning apparatus is only one example that can be used for producing lyocell filament fibers, and the manufacturing method and the manufacturing apparatus applicable to the present invention are not limited to the above description and Fig.

On the other hand, according to another embodiment of the invention, the lyocell filament fibers produced from the lyocell spinning dope can be provided.

As described above, it has been confirmed through experimentation that a lyocell spinning dope containing cotton linter pulp can be applied to a specific production method to provide a lyocell fiber having a low degree of orientation and a low degree of fibrillation.

Since the amount of fibrils formed on the surface of the lyocell fiber obtained by applying the dyestuff for dental use of the lyocell to a specific production method or the degree of fibrillation thereof is very small, the degree of fibrillation is, for example, Therefore, not only the surface feel of the fiber and the quality of the final product are excellent but also the initial elastic modulus can be low, so that it can be easily applied to high-grade clothing fibers such as lining and underwear of clothes.

Accordingly, the lyocell filament fibers may have a degree of fibrillation of 1 or more.

The 'fibrillatization degree' means the degree of fibrillogenesis on the surface of the filament. Specifically, fibrils are generated by rubbing the fibers against each other for a predetermined time based on fibers immersed in water, and the fibrils are observed with an optical microscope Which may be measured from an image obtained by the above method. This 'degree of fibrillation' can be expressed by the following general formula (1), and the lower the number of generated fibrils, the higher the degree of fibrillation.

[Formula 1]

Fibrillation degree (grade) = number of fibrils / filament unit length (0.1 mm)

0 Rating = Fibril 0

1 grade = number of fibrils <10

2 grade = number of fibrils <20

3 grade = number of fibrils <50

4th grade = number of fibrils <100

5 grade = number of fibrils> 100

※ In the fibrillation degree (grade), 0 grade is the highest grade.

As shown in Experimental Example 1 to be described later, the lyocell filament fibers may have an initial elastic modulus of 150 to 230 g / d. The lariocell filament fiber may have a strength of 4 to 8 g / d. The initial elastic modulus and the initial strength may be measured after drying the lyocell filament fibers prepared from the dyestuff for use in the lyocell spinning for 2 hours in an oven at 105 ° C.

These lyocell filament fibers exhibit a low initial elastic modulus while having appropriate strength for clothing, and can be easily applied to high-grade clothing fibers such as lining and underwear of clothes.

According to the present invention, it is possible to provide a lyocell fiber capable of realizing a degree of fibrillation without further processing and having a high elongation and being easily applicable to high-grade garment fibers, a lyocell spinning dope using the same, And a lyocell filament fiber produced therefrom.

1 schematically shows an example of a spinning device which can be used for the production of lyocell filament fibers.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example : Cotton Linter ( cotton linter ) From pulp Lyocell  Production of filament fiber>

Example 1

Pulp powder having a diameter of 1700 탆 or less was prepared by putting a cotton linter pulp having a DP of 1200 in a mill equipped with a 100 mesh filter.

The pulp powder was swelled in a 50 wt% aqueous NMMO solution. At this time, the content of pulp in the NMMO aqueous solution was 6 wt%, and the antioxidant was added in an amount of 0.01 wt% with respect to the cotton linter pulp.

The swollen pulp slurry was maintained at an internal temperature of 90 DEG C and fed to the kneader maintained at an absolute pressure of 50 mmHg at a rate of 16 kg / hour by means of a rotary valve pump. A 50% by weight NMMO aqueous solution was added to 89% The pulp was completely dissolved while removing excess moisture, and then the spinning dope was discharged through the discharge screw.

The spinning dope was radiated using a nozzle having a number of nozzles of 1000 and a nozzle cross-sectional area of 0.47 mm 2 so that the final filament total fineness was 1,650 denier. At this time, an air gap of 30 mm was provided between the nozzle and the coagulating bath. In the air gap, cooling air of 15 ° C was supplied to the dope discharged at a flow rate of 30 m ³ / hr.

The multi-filaments solidified in the coagulating bath through the air gap were washed with water in a five-stage washing machine and then dried in a three-stage drying roll with an untreated multifilament yarn with a water content adjusted to 170% To obtain a lyocell multifilament yarn. At this time, the tension between the first and second stages of the drying roll was adjusted to 0.2 g / d, the tension between the second and third stages was adjusted to 0.5 g / d, and the temperature of each drying roll was sequentially set to 100, 130, Lt; / RTI &gt;

The number of filaments of the lyocell filament yarn manufactured by the above method was 1000, and the average fineness was 1.5 d.

Example 2

A lyocell multifilament yarn was obtained in the same manner as in Example 1, except that a cotton linter pulp with a degree of polymerization (DP) of 800 was used.

< Example : Softwood  From pulp sheet Lyocell  Production of filament fiber>

Comparative Example 1

A softwood pulp sheet (V81, DP 1200 from buckeye) was put into a pulverizer equipped with a 100 mesh filter to prepare a pulp powder having a diameter of 1700 탆 or less.

The pulp powder was swelled in a 50 wt% aqueous NMMO solution. At this time, the content of pulp in the NMMO aqueous solution was 6 wt%, and the antioxidant was added in an amount of 0.01 wt% with respect to the cotton linter pulp.

The swollen pulp slurry was maintained at an internal temperature of 90 DEG C and fed to the kneader maintained at an absolute pressure of 50 mmHg at a rate of 16 kg / hour by means of a rotary valve pump. A 50% by weight NMMO aqueous solution was added to 89% The pulp was completely dissolved while removing excess moisture, and then the spinning dope was discharged through the discharge screw.

The spinning dope was radiated using a nozzle having a number of nozzles of 1000 and a nozzle cross-sectional area of 0.47 mm 2 so that the final filament total fineness was 1,650 denier. At this time, an air gap of 30 mm was provided between the nozzle and the coagulating bath. In the air gap, cooling air of 15 ° C was supplied to the dope discharged at a flow rate of 30 m ³ / hr.

The multi-filaments solidified in the coagulating bath through the air gap were washed with water in a five-stage washing machine and then dried in a three-stage drying roll with an untreated multifilament yarn with a water content adjusted to 170% To obtain a lyocell multifilament yarn. At this time, the tension between the first and second stages of the drying roll was adjusted to 0.2 g / d, the tension between the second and third stages was adjusted to 0.5 g / d, and the temperature of each drying roll was sequentially set to 100, 130, Lt; / RTI &gt;

The number of filaments of the lyocell filament yarn manufactured by the above method was 1000, and the average fineness was 1.5 d.

Comparative Example 2

The lyocell filament fibers were prepared in the same manner as in Comparative Example 1, except that softwood pulp sheets (buckeye V-60, DP 800) were put into a pulverizer equipped with a 100 mesh filter to make pulp powders having a diameter of 1700 쨉 m or less.

< Experimental Example > Example  And Comparative example Lyocell  Measurement of physical properties for filament fiber)

Experimental Example 1 : Measurement of tensile strength and initial modulus

The strength and elongation of the lyocell filament fibers obtained in the above Examples and Comparative Examples were measured at room temperature using a universal material testing machine (Model 5566, Instron) according to American Society for Testing and Materials Association (ASTM) D-885. For the measurement, the lyocell filament fibers obtained in the Examples and Comparative Examples were dried in an oven at 105 ° C for 2 hours.

The specific measurement conditions were as follows, and the measurement results were expressed by the average value of 10 repeated experiments.

 (1) Tensile strength

1) Crosshead speed: 300mm / min

2) Experiment error: ± 1 MPa

(2) Initial modulus

1) Head Speed: 300mm / min

2) Grip Distance: 250mm

3) 25 &lt; 0 &gt; C and 60% RH atmosphere

Experimental Example 2 : Alpha-cellulose of raw pulp ( alpha - cellulose ) Content

The pulp powders in the above Examples and Comparative Examples were immersed in a 17.5% NaOH solution at 20 占 폚 for 20 minutes, and the undissolved material was dried and weighed. At this time, the substance which can not be dissolved is alpha-cellulose, and the content is calculated according to the following general formula (2).

[Formula 2]

The alpha cellulose content (%) of the raw pulp = W / S x 100

[W = dry weight of residual fiber (g), S = dry weight of pulp sample (g)]

Experimental Example 3 : Fibrillation degree  Measure

The filament of the lyocell filament fibers obtained in the above Examples and Comparative Examples was subjected to a reciprocating motion of 10 times per minute by injecting 0.1 g of a filament cut into 5 mm in a cylindrical cylinder having a diameter of 10 mm and a length of 30 mm and 1 ml of pure water, The degree of fibrillation was measured. Specific measurement methods and conditions are as follows.

The fibril image generated by the optical microscope was analyzed and the number of fibrils per unit length was measured. This 'fibrillation degree' can be expressed by the following general formula (1).

[Formula 1]

Fibrillation degree (grade) = number of fibrils / filament unit length (0.1 mm) _

0 Rating = Fibril 0

1 grade = number of fibrils <10

2 grade = number of fibrils <20

3 grade = number of fibrils <50

4th grade = number of fibrils <100

5 grade = number of fibrils> 100

The results of Experimental Examples 1 to 3 are shown in Table 1 below.

Room use dope raw materials Pulp degree of polymerization (DP) The tensile strength
(g / d) Initial modulus (g / d) Content of alpha-cellulose in raw pulp (wt%) Fibrillation degree Example 1 Cotton linters 1200 7.5 220 99.5 One Example 2 Cotton linters 800 5.3 190 99.5 One Comparative Example 1 Softwood pulp 1200 6.8 260 97.1 4 Comparative Example 2 Softwood pulp 800 4.7 240 95.5 5

11: Gear pump
12: spinneret (12)
13: Unclotting fiber
14: First coagulation bath
15: Second coagulation bath
16: Traction roller
17: Flushing device
18: Drying device

Claims (10)

A lyocell spinning dope containing an aqueous cotton linter pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO) is discharged from the spinneret at a temperature of from 80 ° C to 130 ° C ;
Passing the discharged dope through a coagulation bath to solidify the filament;
Washing the filament that has passed through the coagulation bath; And
And drying the washed filament.
The method according to claim 1,
Wherein the lyocell spinning dope comprises 6 to 16 wt% cotton linter pulp; And 84 to 94% by weight of an aqueous solution of N-methylmorpholine-N-oxide.
The method according to claim 1,
Wherein the weight ratio of N-methylmorpholine-N-oxide and water in the N-methylmorpholine-N-oxide aqueous solution is 91: 9 to 83:17.
The method according to claim 1,
Wherein said cotton linter pulp comprises at least 99 wt% alpha-cellulose. delete delete The method according to claim 1,
The step of drying the washed filament comprises applying a tension of 0.1 to 1 g / d at 80 to 200 ° C to the filament.
A cotton linter pulp and an aqueous solution of N-methylmorpholine-N-oxide (NMMO)
A lyocell filament fiber having an intensity of 4 g / d to 8 g / d and an initial modulus of 150 to 230 g / d.
9. The method of claim 8,
The lyocell filament fibers and water were injected into a cylindrical cylinder and sealed, and then subjected to reciprocating motion ten times per second. Thereafter, the lyocell filament fibers observed with an optical microscope, Filament fiber.
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