JPH11140772A - Solvent-spun cellulosic fiber and fibrous structure and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unique touch feeling and to embody excellent dimensional stability and dyeability by treating a solvent-spun cellulosic fiber or its fibrous structure with an alkaline solution, then fibrillating the fiber or fibrous structure and subsequently cutting the resultant fibrils with a cellulase. SOLUTION: An alkaline solution such as an aqueous solution of caustic soda or liquid ammonia is applied to a solvent-spun cellulosic fiber or its fibrous structure composed of a cellulose crystalline phase consisting essentially of II type cellulose and a cellulose noncrystalline phase and having >=53 crystallinity to swell the fiber or fibrous structure by >1.3 times based on the diameter of the fiber or fibrous structure at 25 deg.C and RH 60%. A mechanical stress is then applied thereto to provide >=3 rating of fibrillation degree. The resultant fiber or fibrous structure is then treated with a cellulase to cut the formed fibrils.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent-spun cellulosic fiber substantially composed of a cellulose crystalline phase and a cellulose amorphous phase having reduced fibrillation in particular, and a fiber structure comprising the cellulosic fiber. The present invention relates to a product and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, pulp has been used as a raw material, cellulose in the pulp has been dissolved in an organic solvent such as N-methylmorpholine-N-oxide, and the resulting spinning dope has been diluted with a dilute aqueous solution of N-methylmorpholine-N-oxide. Solvent-spun cellulosic fibers obtained by spinning into a spinning bath (see, for example, U.S. Pat. No. 4,246,221) are trade names "TENCEL" (Courtles, UK) and "Riocell by Lenting" (Austrian renting). Is commercially available. These solvent-spun cellulosic fibers have high strength, and have the property that the strength hardly decreases even under wet conditions, but the fibers are split in a fluffy state in the fiber axis direction due to friction on the fiber surface, especially friction under wet conditions. So-called fibrils are liable to occur, and they become rigid under wet conditions.

Conventionally, as a method for reducing fibrillation of solvent-spun cellulosic fibers, a method of treating fibers with a cross-linking agent such as triacryloylhexahydrotriazine, N, N'-methylenebisacrylamide (Tokuhyo Hei 8-50)
No. 5441), a method of cross-linking a solvent-spun cellulose fiber with a cross-linking agent such as polyethylene glycol having a functional group at the terminal and cellulose and low formaldehyde reactive with the functional group at the terminal (Japanese Patent Application Laid-Open No. 8-507334).
Japanese Patent Application Laid-Open No. Hei 8 (1994) -108, a method of refining a solvent-spun cellulosic fiber fabric and treating it with a low formaldehyde cross-linked resin or the like.
JP-A-511834), a method of treating a solvent-spun cellulosic fiber with an aqueous solution or dispersion of a polymer having a plurality of cationic ionization sites under wet conditions (Japanese Patent Application Laid-Open No. Hei 6-5).
No. 01994), a method of treating a solvent-spun cellulosic fiber with a colorless chemical reagent having a dichlorotriazinyl ring, a trichloropyrimidinyl ring and the like (JP-A-5-11).
No. 7970), and a method of treating a solvent-spun cellulosic fiber with a crosslinking agent having at least two vinyl sulfone groups under wet conditions (Japanese Patent Application Laid-Open No. 7-508320).

However, in the method using these resins and cross-linking agents, fibrillation can be reduced, but the natural texture and good touch inherent to the solvent-spun cellulose fibers are impaired. Also, as a method of processing cotton yarn cloth having different microstructure of solvent-spun cellulosic fiber and fiber, for the purpose of imparting gloss, dimensional stability, dye, processing agent exhaustion, increasing fiber strength, etc., under tension After applying a high-concentration aqueous solution of 20% or more to the cotton yarn cloth for about 60 seconds, wash and neutralize it with water, neutralize it to remove alkali, and apply rich caustic soda to cotton to eliminate twisting of the fiber, Mercerization, which smoothes the surface and rounds the cross section of the bean-like fiber, has been known for a long time.

[0005] However, the alkali treatment technique of the cotton yarn cloth does not give any suggestion as to the action and effect that the fibrillation can be reduced by treating the solvent-spun cellulose fiber with an alkali. This is because cotton has a different microstructure from the solvent-spun cellulosic fiber as described later, and does not fibrillate.

[0006]

In view of the above-mentioned current state of cellulosic fiber processing, the present inventors have conducted intensive studies on swelling processing of solvent-spun cellulosic fibers, particularly swelling processing using an alkaline solution. Solvent-spun cellulosic fibers are found to have different behavior from conventional cellulosic fibers such as natural cotton fibers such as cotton, viscose, polynosic, cupra, etc., and have completed the present invention. is there.

[0007] Incidentally, the solvent-spun cellulosic fiber or the fiber structure comprising the same according to the present invention, when swollen to a specific range, has increased flexibility in water, and has been conventionally difficult to prepare fibrils. Its physical properties and structure change variously according to swelling processing conditions, such as smooth processing of fiber processing in an aqueous solution such as dyeing processing.

For example, when treated under no tension, solvent-spun cellulosic fibers and fiber structures having a soft feel and excellent in washing shrinkage and dyeing properties can be obtained. Further, when treated under tension, a solvent-spun cellulosic fiber and a fibrous structure having a pseudo-like feel and excellent processing dimensional stability can be obtained.

Surprisingly, when swelling is performed using an alkaline solution, fibrillation is reduced and the form of the fibers constituting the object to be treated is repeatedly immersed in water and subsequently dried. Fibers or fibrous structures are also retained.

An object of the present invention is to provide a solvent-spun cellulosic fiber and a fibrous structure having reduced fibrillation, and a method for producing the same. Another object of the present invention is to provide a solvent-spun cellulosic fiber and a fibrous structure capable of maintaining moderate flexibility in water and smoothly promoting fibril adjustment processing and dyeing processing in an aqueous solution, and a method for producing the same. is there. Still another object of the present invention is to have a unique texture,
An object of the present invention is to provide a solvent-spun cellulosic fiber and a fiber structure excellent in wrinkle resistance, dimensional stability, and dyeability, and a method for producing the same. Still other objects and effects of the present invention will be apparent from the following description.

[0011]

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention comprises a solvent-spun cellulosic fiber comprising a cellulose crystalline phase and a cellulose amorphous phase. And a solvent-spun cellulosic fiber and a fiber structure, wherein the fiber has shape retention properties. Here, the fibers and the fiber structures mean raw cotton, yarn, rope, knit, woven fabric, non-woven fabric and the like. The form retention means that the form of the fiber which has been subjected to swelling processing with an alkaline solution or the like, washed with water, and dried is repeatedly immersed in water and then retained after drying.

Further, the invention according to claims 2 to 7 of the present invention comprises solvent-spun cellulosic fibers substantially consisting of a cellulose crystalline phase and a cellulose amorphous phase, respectively, and the fibers have a shape retention property. Solvent-spun cellulosic fibers and fibrous structures having a shape retention property provided by application of an alkaline solution, an aqueous solution of caustic soda, an aqueous solution of caustic potash, or liquid ammonia, and having a fibrillation degree of 3 These are those having a dye adsorption ratio of 1.3 or more, or those having a fiber crystallinity of 53 or more.

The invention according to claim 8 is substantially equivalent to II.
A solvent-spun cellulose fiber comprising a crystalline phase mainly composed of type cellulose and a cellulose amorphous phase or a fibrous structure composed of the cellulosic fiber, by applying an alkaline solution under no tension to the fiber or the fibrous structure. Fiber diameter of 2
This is a method for producing a solvent-spun cellulosic fiber and a fiber structure that swells more than 1.3 times the diameter of the fiber at 5 ° C. and RH of 60%. A ninth aspect of the present invention is the method for producing a solvent-spun cellulosic fiber and a fibrous structure according to the eighth aspect, wherein the alkaline solution is an aqueous solution of caustic soda.

Further, according to the present invention, there is provided a solvent-spun cellulosic fiber comprising a crystalline phase mainly composed of type II cellulose and a cellulose amorphous phase, or a fiber structure comprising the cellulosic fiber. (A) applying an alkaline solution to swell the fiber or the fiber constituting the fiber structure so that the diameter of the fiber exceeds 25 times the fiber diameter at 25 ° C. and 60% RH by 1.3 times; b) applying mechanical stress to develop fibrils;
(C) applying fibril by applying cellulase,
And producing a solvent-spun cellulosic fiber or fiber structure.

The above steps (a), (b) and (c) may be performed in this order, but after the step (b), the step (c) is performed and then the step (a) is performed. After the step (b), the step (a) is performed and then the step (c) is performed. Alternatively, the steps (b) and (a) are simultaneously performed, that is, the fibrils are formed by applying a mechanical stress in an alkaline solution. After the expression, the step (c) may be performed.

[0016]

Next, an embodiment of the present invention will be described. The solvent-spun cellulosic fibers used in the present invention are those obtained by spinning a spinning stock solution obtained by dissolving cellulose in an organic solvent. As an example, the cellulose in the pulp is dissolved in an organic solvent such as N-methylmorpholine-N-oxide, and the filtered spinning solution is filtered into N-
There is a solvent-spun cellulosic fiber obtained by spinning into a spin bath such as a dilute aqueous solution of methylmorpholine-N-oxide.

These fibers are disclosed in US Pat.
No. 221; "Tencel" (Courtles, UK);
It is commercially available under a trade name such as "Lenting" (Austrian Lenting).

The solvent-spun cellulosic fiber used in the present invention is, first, substantially composed of a crystalline phase mainly composed of type II cellulose and a cellulose amorphous phase. Completely different from natural cellulose fibers such as cotton. That is, in the X-ray diffraction pattern of the solvent-spun cellulose fiber substantially consisting of a crystalline phase mainly composed of type II cellulose, there is almost no diffraction peak at a diffraction angle of 15 ° observed in type I cellulose such as cotton.

Second, cotton has a structure in which highly crystallized microfibrils joined by a colloid having a width of 90 to 100 ° are arranged in a helical manner, and although it is highly crystalline, it does not exhibit a fibrillation phenomenon. . The solvent-spun cellulose fiber used in the present invention has a structure in which highly crystallized microfibrils are linearly arranged in the fiber axis direction, and causes a fibrillation phenomenon.

The solvent-spun cellulose fiber has a particularly high alkali resistance as compared with regenerated fiber such as viscose rayon. As a processing method for treating regenerated fibers such as viscose rayon with an alkaline solution, a dyeability improving treatment in which the fiber is treated with a 4 to 5% by weight aqueous solution of caustic soda is known. However, regenerated fibers such as viscose rayon have poor alkali resistance and can be treated with a 4 to 5% by weight aqueous solution of caustic soda. When treated with a high concentration aqueous solution of caustic soda exceeding 10% by weight, the fibers become rigid. More often than not, the fibers elute, agglomerate and dissolve. On the other hand, in the case of the solvent-spun cellulose fiber, it has sufficient durability even when treated with a high-concentration aqueous solution of caustic soda of 30% by weight or more, and swells in the solution, but maintains an appropriate elasticity.

An important point in the present invention is that an alkaline solution or the like is applied to swell the fibers. For example, 2
When dipping Tencel fiber manufactured by Coatles Co., Ltd. in a 11% by weight aqueous solution of caustic soda at 5 ° C., the fiber diameter increases to 300% based on the fiber of RH 60% at 25 ° C., while the fiber length decreases by 18% and the volume swelling ratio increases In terms of swelling, it swells to 740%. The swelling ratio of the fiber diameter when immersed in water is 13
Given that it is about 0%, swelling using an alkaline solution such as caustic soda swells greatly beyond the degree of swelling in water. The first feature of the swelling treatment of an alkaline solution that greatly exceeds the degree of swelling in water is that the form of the yarn swelled with an alkaline solution, washed with water, and dried,
It is to be kept after repeated immersion in water and subsequent drying.

Other phenomena such as an increase in the amount of dye adsorbed and the degree of fiber crystallinity, but a decrease in fiber strength, fibrillation degree and the like are observed. As a result, effects such as an increase in drapability, retention of flexibility, a reduction in wrinkles, an increase in dyeability, and an increase in washing stability are exhibited. Although the reason for this is not clear, for example, changes in the hydrogen bonding state within the molecules of the solvent-spun cellulose fiber and between the molecules, an increase in the voids in the cellulose fiber due to the cleavage of the cellulose molecular chain, and the swelling of the crystal part in the non-crystalline part It is also considered that the internal structure of the cellulose fiber has changed, such as an increase in crystallinity and a decrease in the degree of crystal orientation.

Further, in the case of a fiber structure, when the stress generated by swelling strongly acts on the woven structure of the fiber structure, the fibers and yarns constituting the fiber structure may be deformed in the cross section of the fiber, In some cases, it is subjected to deformation such as crimping, and is permanently fixed in the deformed form. Examples of the alkaline solution applied to the present invention include various solutions such as caustic soda aqueous solution, caustic potassium aqueous solution, and liquid ammonia.
An aqueous caustic soda solution is particularly preferred in that the decrease in the degree of polymerization is insignificant.

In the present invention, the kind of alkali to be applied, the concentration of alkali solution to be treated, the temperature, the time, the method of application, etc., and the kind of fiber or fiber structure to be treated, etc. Because of having various characteristics,
Although preferable processing conditions and embodiments cannot be specified unconditionally, the case where an aqueous solution of caustic soda is used is roughly described as follows. From the viewpoint of the effect of fiber deterioration, the preferred treatment temperature of the aqueous sodium hydroxide solution is 20 to 30C.
The preferred concentration of the aqueous solution of caustic soda varies depending on the purpose of processing. One example is as follows.

The content is 7 to 8% by weight for improving the dyeability and 10 to 30% by weight for improving the elasticity. Such an aqueous solution of caustic soda is applied to the fiber or fibrous structure by a conventional method such as padding, dipping, or spraying, and then neutralized with an acid, washed with water, and dried.

[0026]

Next, embodiments of the present invention will be described more specifically with reference to the following examples. It goes without saying that the present invention should not be limited only by these examples. In the examples, the measurement and evaluation of the physical properties and performance of the fiber or the fibrous structure were performed by the following methods.

(1) Evaluation of the degree of fibrillation The degree of fibrillation was evaluated in accordance with JIS L 1042 method F-2.

(2) Dye Adsorption Ratio Kayarus Blue 4BL (Nippon Kayaku Co., Ltd. direct dye) 0.5% owf, anhydrous sodium sulfate (neutral salt) 5% owf
After immersion in a dye bath at 95 ° C. for 40 minutes (after immersion for a short time, washing with water and drying), the amount of dyeing was measured by a spectrophotometer, and the value was calculated by the following formula: Ratio of dye adsorption rate = (Alkaline solution swelling) Dye adsorption amount of treated fiber / (Dye adsorption amount of untreated fiber)

(3) Measurement of woven fabric softness Measured by 45 ° cantilever method.

[0030]

Example 1 Coatles "Tencel" fiber at 25 ° C.
When the fiber was immersed in an aqueous 11% by weight caustic soda solution for 10 minutes, the fiber diameter swelled up to three times. Subsequently, the swollen fiber was neutralized with an acid, washed with water, and the undried fiber was immersed in water. As a result, the diameter swelling of the fiber was doubled. When this product was dried, it returned to one-fold, in other words, the fiber diameter before immersion in the aqueous sodium hydroxide solution. The degree of swelling in aqueous caustic soda is
The degree of swelling of the fiber diameter when immersed in water at 25 ° C. for 10 minutes was larger than 1.3 times the degree of swelling, but moderate elasticity was maintained.

The crystallinity of the Tencel fiber manufactured by Coulters Co., Ltd. and the fiber after the swelling test in the above-mentioned aqueous sodium hydroxide solution was measured by ¹³ C solid state nuclear magnetic resonance.
± 2% and 55 ± 2%. From the above experimental results, it can be seen that when the solvent-spun cellulosic fiber is immersed in an aqueous solution of caustic soda, it swells more than in water and the crystallinity increases.

[0032]

Example 2 The procedure of Example 1 was repeated, except that Tencel greige (TP1080, sold by Toshima Co., Ltd.) was used instead of Tencel fiber manufactured by Coatles Co., Ltd. The same swelling experiment with an aqueous solution of caustic soda as in Example 1 was performed. When the yarn taken out of the Tencel fabric after the swelling test in an aqueous solution of caustic soda was immersed in water, it partially stretched straight. However, when the yarn was dried, it shrank and returned to the original yarn form before immersion in water. Refining of a Tencel greige machine (TP 1080 sold by Toshima Co., Ltd.), the yarn taken out from the desizing fabric stretched straight when immersed in water, and remained straight even when dried.

From the above experimental results, it is understood that when the solvent-spun cellulose fiber yarn is immersed in an aqueous solution of caustic soda, the shape of the yarn before immersion is maintained.

[0034]

Example 3 A solution of caustic soda having a concentration (% by weight) shown in the table below in 100% plain woven fabric (30/1 × 30/1, 92 × 68 / in Sale No. TP3030) manufactured by refining and desizing. After padding, neutralization with acetic acid using a lattice conveyor, washing with water and dehydration, 80 ° C. ×
Tumble dry for 60 minutes. Table 1 shows the softness and softness in the longitudinal direction of the dry woven fabric and the 100% moisture content woven fabric when the treatment concentration of the aqueous caustic soda solution is changed as shown in Table 1 below.

[0035]

From the above experimental results, it can be seen that the fabric swelled with the aqueous solution of caustic soda is softer in a wet state than in a dry state.

[0037]

Example 4 100% plain Tencel fabric (30/1 × 30/1, 92 ×
68 / in Toshima Co., Ltd. sales part number TP3030)
Was fibrillated for 60 minutes with a washer filled with a 13% by weight aqueous solution of caustic soda at 25 ° C., and swelling treatment with an aqueous solution of caustic soda was performed. Subsequently, the obtained fabric to be treated was subjected to an enzyme treatment at 50 ° C. for 2 g / 1 × 60 minutes with a cellulolytic enzyme cellulase. The stretch rate of the woven fabric treated with the enzyme was 18.0% (through), 7.0% (weft), and the stretch recovery rate after 1 hour was 45.0%.

[0038]

Example 5 A 100% plain Tencel fabric (30/1 × 30/1, 92 ×
68 / in Toshima Co., Ltd. sales part number TP3030)
The knitted fabric OT1460 (manufactured by Daiichi Knit Co., Ltd.) was used as a test sample, and subjected to an aqueous caustic soda treatment under no tension and under tension.

Here, the aqueous solution of caustic soda under tension means that an aqueous solution of caustic soda is stretched beyond the shrinkage dimension of the object to be processed under the aqueous solution of caustic soda under no tension. I do.

(Unstressed Treatment) A sample was put into a washer filled with a 13% by weight aqueous solution of caustic soda at 30 ° C., and swelled with an aqueous solution of caustic soda at a drum rotation speed of 18 rpm for 60 minutes.
Fill the washer with water at 0 ° C and rotate the drum at a speed of 18 rpm.
The washing with water for 5 minutes at m was repeated three times by changing water. Subsequently, a 30 ° C. acetic acid aqueous solution was charged into a washer and neutralized at the same speed for 10 minutes, washed with 40 ° C. water for 5 minutes, washed with 30 ° C. water for 5 minutes, centrifugally dehydrated, and tumbled.

(Unstrained treatment) Except that a sample having the same size as the pin frame was fixed to the pin frame and used for the test, the treatment was performed under the same conditions and operations as those of the above-described unstrained treatment. The above-mentioned woven fabric and knitted fabric were subjected to five washing tests according to the JIS L0217 H03 method. Table 2 shows the results of measuring the processing shrinkage of the woven fabric and the knitted fabric with respect to the test woven fabric and the knitted fabric.

[0042]

From the results shown in the above table, it can be seen that the woven fabric and the knitted fabric under tension have smaller processing shrinkage and are more excellent in processing dimensional stability. Table 3 shows the results of measuring the washing shrinkage of the woven fabric and the knitted fabric after the washing test on the woven fabric and the knitted fabric.

[0044]

From the results in the above table, it can be seen that
It can be seen that the cloth to be treated in the cloth to be treated, the knitted fabric and the treatment under tension has a very small washing shrinkage, and is excellent in laundry form stability. Further, it can be seen that the washing shrinkage rate of the knitted fabric in the under-straining process has no practical problem.

[0046]

According to the present invention, fibrillation is reduced, moderate flexibility is maintained in water, fibril adjustment processing and dyeing processing in an aqueous solution can be smoothly promoted, and a unique feeling is obtained. Thus, a solvent-spun cellulosic fiber and a fiber structure having excellent dimensional stability and dyeability can be obtained.

Claims (10)

[Claims] 1. A solvent-spun cellulosic fiber comprising a solvent-spun cellulosic fiber substantially consisting of a cellulose crystalline phase and a cellulose amorphous phase, wherein the fiber has a shape-retaining property. Fibers and fiber structures. 2. The solvent-spun cellulosic fiber and fiber structure according to claim 1, wherein the form retention is imparted by applying an alkaline solution. 3. The solvent-spun cellulosic fiber or fiber structure according to claim 1, wherein the alkaline solution is an aqueous solution of caustic soda. 4. The solvent-spun cellulosic fiber or fiber structure according to claim 1, wherein the alkaline solution is liquid ammonia. 5. fibrillation degree solvent-spun cellulosic fibers and the fiber structure according to any one of the tertiary or more claims 1 to 4 wherein. 6. solvent-spun cellulosic fibers and the fiber structure according to any one of claims 1 to 5 wherein the ratio of the dye adsorption ratio is 1.3 or more. 7. The solvent-spun cellulosic fiber and the fiber structure according to claim 1, wherein the fiber crystallinity of the solvent-spun cellulosic fiber is 53 or more. 8. An alkaline solution is applied to a solvent-spun cellulose-based single fiber consisting essentially of a crystalline phase mainly composed of type II cellulose and a cellulose amorphous phase or a fiber structure composed of the cellulose-based fiber, A solvent-spun cellulosic fiber or fiber structure, characterized in that the fiber or the fiber structure has a diameter of a single fiber at a temperature of 25 ° C. and RH of 60% is swollen by more than 1.3 times based on the diameter of the single fiber. Production method. 9. The method according to claim 8, wherein the alkaline solution is an aqueous sodium hydroxide solution. 10. An (a) alkaline solution is added to a solvent-spun cellulose-based fiber substantially consisting of a crystalline phase mainly composed of type II cellulose and a cellulose amorphous phase or a fiber structure composed of the cellulose-based single fiber. Applied, and the diameter of the fiber or the single fiber constituting the fiber structure is set at 25 ° C., RH
A step of swelling more than 1.3 times based on the diameter of a single fiber of 60%, (b) a step of applying mechanical stress to develop fibrils, (c) a step of applying cellulase and cutting fibrils, A method for producing a solvent-spun cellulosic fiber or a fibrous structure, comprising: