JP2001049520A - Cellulose triacetate fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cellulose triacetate fiber imparted with a soft feeling, flexibility and wet feeling, and to provide its method of production. SOLUTION: This triacetate fiber constituted of plural single fibers consists of single fibers of which >=60% of the total single fibers has >=0.11 dtex and <0.89 dtex single fiber fineness, and the method for producing the cellulose triacetate fiber comprises removing only cellulose diacetate component in a composite fiber in which the cellulose triacetate component is partitioned as plural by the cellulose diacetate components at the cross section in right angle direction to the fiber axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulose triacetate fiber for clothing which gives a new texture and a method for producing the same.

[0002]

2. Description of the Related Art Cellulose-triacetate fiber is a pulp as a main raw material, is called a semi-synthetic fiber, and is a characteristic fiber having characteristics of a natural fiber. Has many excellent characteristics as a fiber for clothing, such as moderate hygroscopicity.

[0003] On the other hand, recent needs have become extremely diversified and sophisticated, and in order to market fiber materials that are acceptable to consumers, it is not only the characteristics of fibers derived from a polymer substrate but also new ones. It is indispensable to provide a differentiating texture and special functions. Against this background, various textures have been improved in cellulose acetate fibers by using various means such as changes in the cross-sectional shape of the fibers and changes in the side morphology. Modification is used as a means that greatly contributes to the improvement of texture, such as impartation of softness, flexibility, and wetness.

However, for cellulose acetate fibers based on the dry spinning method, the winding from the nozzle hole discharge is difficult due to the characteristics of the molecular structure of the polymer itself and the fact that the fiber formation is almost completed immediately after the discharge from the nozzle hole. Stretching in the spinning cylinder until take-up and in post-processing after winding is almost difficult.

[0005] Therefore, in dry spinning of cellulose acetate, the fineness of a single fiber is almost determined by the hole diameter of the nozzle, and in order to obtain an ultrafine yarn, it is necessary to use a nozzle having a pore diameter not found in other synthetic fibers. was there.

[0006] For example, Japanese Patent Publication No. Hei 8-501606 discloses a method of spinning with a nozzle having a pore diameter of 36 μm or less to obtain a cellulose acetate fiber having a single fiber fineness of 1.56 dtex or less. . However, even if this technique is used, the region where stable spinning is possible is approximately 1.11 d.
tex was the limit.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, and provides a cellulose triacetate fiber having a soft feeling, a suppleness and a wet feeling, and its production. It is to provide a method.

[0008]

The gist of the present invention is that in a cellulose triacetate fiber composed of a plurality of single fibers, 60% or more of all the single fibers have a single fiber fineness of 0.1.
The cellulose triacetate fiber is a single fiber of 1 dtex or more and less than 0.89 dtex, and the cellulose triacetate component is divided into a plurality by the cellulose diacetate component in a cross section perpendicular to the fiber axis. A method for producing cellulose triacetate fiber, comprising dissolving and removing only the cellulose diacetate component of the conjugate fiber.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below. The cellulose triacetate fiber of the present invention is composed of a plurality of single fibers, and at least 60% of all single fibers have a single fiber fineness of 0.11 dtex or more,
It must be a single fiber of less than 0.89 dtex. If the single fiber fineness is less than 0.11 dtex, the yarn quality of the single fiber is significantly reduced, and problems such as yarn breakage and fluffing occur. When the single fiber fineness is 0.89 dtex or more, the softness, flexibility, and wetness, which are the objects of the present invention, are insufficient.

[0010] Further, the single fiber fineness is 0.11 dtex or more,
Even when the single fiber of less than 0.89 dtex is less than 60% of all the single fibers constituting the cellulose triacetate fiber, the soft feeling, the flexibility and the wet feeling are insufficient.

Next, the method for producing the cellulose triacetate fiber of the present invention will be described in detail.

The cellulose triacetate fiber of the present invention has a cross section perpendicular to the fiber axis, which is obtained by dissolving and removing only the cellulose diacetate component of the conjugate fiber in which the cellulose triacetate component is divided into a plurality by the cellulose diacetate component. can get. The composite fiber is obtained by a dry spinning method by discharging a spinning dope into a high-temperature atmosphere by a composite spinning nozzle that distributes the cellulose triacetate component so as to divide the cellulose triacetate component into a plurality of components by the cellulose diacetate component. From the standpoint of yarn production stability, fineness of a single fiber, and fiber quality, a cross-section perpendicular to the fiber axis is preferably a laminated structure of two or more layers in which cellulose diacetate components and cellulose triacetate components are alternately arranged. The cross section in the direction perpendicular to the fiber axis is a laminated structure consisting of three layers, the intermediate layer consisting of a cellulose diacetate component, and both end layers dissolving only the intermediate layer of a composite fiber consisting of a cellulose triacetate component. More preferably, two cellulose triacetate fibers are used.

[0013] Such a conjugate fiber in which the cross section in the direction perpendicular to the fiber axis is a laminated structure composed of three layers, the intermediate layer is composed of a cellulose diacetate component, and both end layers are composed of a cellulose triacetate component. For example, it can be manufactured as follows.

Cellulose diacetate and cellulostriacetate are dissolved in methylene chloride or a mixed solvent of methylene chloride and methanol, respectively, and the concentration of each is 15% by weight or more and 30% by weight or less, preferably 18% by weight. % To 27% by weight or less. Thereafter, using the two kinds of spinning dope, cellulose diacetate is disposed in the intermediate layer, and cellulose triacetate is disposed in both end layers, and the composite spinning nozzle which distributes the laminated three-layer structure is used. And spinning and winding by dry spinning.

[0015] The ratio of each component in the conjugate fiber is not particularly limited, but the fineness of the conjugate fiber and the subsequent dissolution and removal are determined according to the fineness of the target single fiber of cellulose triacetate fiber. What is necessary is just to determine in consideration of the ratio of the cellulose diacetate component used.

Further, in order to change the gloss, specific gravity, texture and the like of the fiber, an inorganic substance may be added to one or both of the two types of spinning dope described above.

The cellulose diacetate component dissolved and removed from the conjugate fiber has an average acetylation degree of 48.8% or more and 56.
Less than 2% is preferred. When the average acetylation degree is less than 48.8%, the cellulose diacetate component is hardly dissolved in a solvent,
It tends to be difficult to dissolve and remove the cellulose diacetate component to obtain split cellulose triacetate fibers.

When the average degree of acetylation is 56.2% or more, the degree of acetylation is high. Therefore, when a solvent capable of dissolving and removing the component is selected, the cellulose triacetate component is also easily swelled and dissolved to obtain. The fineness of cellulose triacetate is reduced, and fluff and yarn breakage are likely to occur.

[0019] The average acetylation degree of the cellulose triacetate component, which is to become ultrafine fibers, must be 56.2% or more. When the average acetylation degree is less than 56.2%, the cellulose triacetate component is also dissolved when the cellulose diacetate component is dissolved and removed, and the fineness of the obtained single fiber becomes too small, and fluff and yarn breakage are liable to occur.

Further, in the present invention, it is necessary to dissolve and remove only the cellulose diacetate component without dissolving the cellulose triacetate component, and the solvent for dissolving and removing only the cellulose diacetate component is easy to handle. Acetone, an aqueous solution of acetone, a mixed organic solvent containing acetone as a main component, or the like is preferable for economic reasons.

The processing conditions for dissolving and removing only the cellulose diacetate component are not particularly limited, and the solvent concentration,
Processing temperature, processing time, and the like can be determined. For example, when the component ratio between the cellulose diacetate component and the cellulose triacetate component is 50:50, the treatment temperature is preferably 25 ° C. and the treatment time is preferably 3 to 10 minutes with 70% by volume of an acetone aqueous solution.

Further, in the present invention, the treatment for dissolving and removing only the cellulose diacetate component may be performed on the original yarn before fabric formation or after fabric formation, and is not particularly limited. However, in consideration of the fact that the fineness of the single fiber becomes extremely fine and the problem that the post-processability of the original yarn tends to occur due to fluffing or the like is likely to occur, it is preferable to carry out the process after fabric formation.

[0023]

The present invention will be described below with reference to examples. Further, the measuring method of the single fiber fineness of the cellulose triacetate fiber after division was performed by the following method. A cross-sectional photograph of cellulostriacetate of 84 dtex 20 filaments was taken with an optical microscope, and a single fiber was cut out from the photograph to determine an area by a weight method, and the average area of the single fiber was set to an area of 4.2 dtex. From the composite fiber obtained in the present invention, the cellulose diacetate component was completely dissolved and removed, and the cross section of the obtained cellulose triacetate fiber was photographed with an optical microscope, and the area of each single fiber was measured in the same manner as in 4.2dte
The area of x was converted into dtex.

(Example 1) Cellulose triacetate having an average acetylation degree of 61.6% was dissolved in a mixed solvent containing methylene chloride / methanol as a main component, and a spinning dope having a solid content of 21.95% by weight. It was created. On the other hand, the average acetylation degree is 55.
2% cellulose diacetate was dissolved in a mixed solvent containing methylene chloride / methanol as a main component, and the solid content was 2%.
A spinning dope of 2.10% by weight was prepared.

Using the above two spinning stock solutions, cellulose diacetate is disposed in the intermediate layer and cellulose triacetate is disposed in both end layers. The component ratio of the cellulose diacetate component to the cellulose triacetate component is set to 20:80, and the nozzle shape is round. Cross section, nozzle hole diameter 0.028 mm, winding speed 5
84 dtex, 6 by dry spinning at 00 m / min.
Thus, a laminated 3-layer cellulose acetate composite fiber having 0 filaments was obtained.

Next, the obtained laminated cellulose acetate composite fiber having a three-layer structure is formed into a fabric, and the cellulose diacetate component is completely dissolved and removed under the following conditions to obtain a fabric comprising the cellulose triacetate fiber of the present invention. Obtained. Treatment conditions Treatment solution: Aqueous acetone solution (70% by volume) Treatment temperature: 25 ° C. Treatment time: 5 minutes The obtained cellulose triacetate fiber has a single fiber fineness of 0.40 dtex or more and less than 0.70 dtex. The fabric made of fiber is extremely soft,
It had a suppleness and a texture excellent in wet feeling.

(Example 2) Using the same two kinds of spinning dope as in Example 1, cellulose diacetate was disposed in the intermediate layer and cellulose triacetate was disposed in both end layers, and the components of the cellulose diacetate component and the cellulose triacetate component were used. The ratio is 50:50, the nozzle shape is a round cross section, and the nozzle hole diameter is 0.
By a dry spinning method at 028 mm and a take-up speed of 500 m / min, a laminated 3-layer cellulose acetate composite fiber of 84 dtex and 60 filaments was obtained.

Next, the obtained cellulose acetate conjugate fiber was made into a fabric, and the cellulose diacetate component was completely dissolved and removed under the same conditions as in Example 1 to obtain a fabric comprising the cellulose triacetate fiber of the present invention.

[0029] The obtained cellulose triacetate fiber has a single fiber fineness of 0.25 dtex or more and 0.45 d
The cloth made of less than tex and made of the fiber had an extremely soft feeling, suppleness, and a feeling excellent in wet feeling.

(Example 3) As in Example 1, two kinds of spinning dope were used, and cellulose diacetate was disposed in the intermediate layer and cellulose triacetate was disposed in both end layers. Components of the cellulose diacetate component and the cellulose triacetate component were used. The ratio is 50:50, the nozzle shape is a round cross section, and the nozzle hole diameter is 0.
By a dry spinning method at 024 mm and a take-up speed of 500 m / min, an 84 dtex, 75 filament laminated type three-layer cellulose acetate composite fiber was obtained.

Next, after the obtained cellulose acetate conjugate fiber was made into a fabric, the cellulose diacetate component was completely dissolved and removed under the same conditions as in Example 1 to obtain a fabric comprising the cellulose triacetate fiber of the present invention.

[0032] The obtained cellulose triacetate fiber had a single fiber fineness of 0.20 dtex or more and 0.40 d
The cloth composed of the fibers having a texture of less than tex had an extremely soft texture, suppleness, and excellent texture.

(Comparative Example 1) 84 obtained under the conditions of Example 1
After fabricating the laminated cellulose acetate composite fiber having a dtex of 60 filaments and a 60-filament, the cellulose diacetate component was dissolved and removed under the following conditions. Treatment conditions Treatment solution: acetone aqueous solution (70% by volume) Treatment temperature: 25 ° C. Treatment time: 1 minute The obtained cellulose triacetate fiber has a fineness of 0.
Monofilaments of 11 dtex or more and less than 0.89 dtex accounted for 35% of the constituent filaments, and the fabric made of the fibers had insufficient softness, flexibility, and wetness.

Comparative Example 2 According to a conventional method for producing cellulose triacetate fiber, cellulose triacetate having an average acetylation degree of 61.6% was dissolved in a mixed solvent containing methylene chloride / methanol as a main component, and solid content was measured. Concentration 21.9
A 5% by weight spinning stock solution was prepared. Using this spinning dope, a cellulostriacetate fiber having 56 dtex and 50 filaments was obtained by a dry spinning method. The single fiber fineness of the obtained cellulose triacetate fiber is 1.01 to
1.28 dtex, and the texture of the fabric made of the fibers was insufficient in softness, suppleness, and wetness.

(Comparative Example 3) Using the same two kinds of spinning dope as in Example 1, cellulose diacetate was disposed in the intermediate layer and cellulose triacetate in both end layers, and the components of the cellulose diacetate component and the cellulose triacetate component were used. The ratio was 20:80, the nozzle shape was round, and the nozzle hole diameter was 0.
By a dry spinning method at 038 mm and a take-up speed of 500 m / min, a laminated 3-layer cellulose acetate composite fiber having 84 dtex and 20 filaments was obtained.

Next, after the obtained cellulose acetate conjugate fiber was made into a fabric, the cellulose diacetate component was completely dissolved and removed under the same conditions as in Example 1 to obtain a fabric comprising the cellulose triacetate fiber of the present invention.

[0037] The obtained cellulose triacetate fiber had a single fiber fineness of 1.50 dtex or more and 1.90 d.
consisting of a single fiber of less than tex, the fabric consisting of the fiber is:
Soft feeling, suppleness, and wet feeling were insufficient.

[0038]

According to the present invention, in a cellulose triacetate fiber composed of a plurality of single fibers, 60% or more of all the single fibers have a single fiber fineness of 0.11 dtex or more.
By using a single fiber of less than 0.89 dtex, a cellulose triacetate fiber having excellent softness, flexibility, and wetness can be obtained. In addition, the cross-section in the direction perpendicular to the fiber axis has a cellulose triacetate component, which is divided into a plurality of cellulose diacetate components by dissolving and removing only the cellulose diacetate component. Triacetate fiber can be obtained stably.

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Claims (6)

[Claims] 1. In a cellulose triacetate fiber composed of a plurality of single fibers, 60% or more of all the single fibers have a single fiber fineness of 0.11 dtex or more and 0.89 dte.
A cellulostriacetate fiber, which is a single fiber of less than x. 2. A cellulose triacetate comprising a cellulose triacetate component in which a cellulose triacetate component is divided into a plurality of cellulose triacetate components in a cross section perpendicular to the fiber axis, wherein only the cellulose diacetate component is dissolved and removed. -A method for producing fiber. 3. A method for dissolving and removing only the cellulose diacetate component of a composite fiber having a laminated structure of two or more layers in which a cellulose diacetate component and a cellulose triacetate component are alternately arranged in a cross section perpendicular to the fiber axis. A method for producing cellulose triacetate fiber. 4. A composite structure in which the cross section in the direction perpendicular to the fiber axis is a laminated structure composed of three layers, wherein the intermediate layer is composed of a cellulose diacetate component and both end layers are composed of a cellulose triacetate component. 4. The method for producing cellulose triacetate fiber according to 3. 5. The cellulose acetate diacetate component has an average degree of acetylation of 48.8% or more and less than 56.2%, and the cellulose acetate component has an average acetylation degree of 56.2% or more. The method for producing a cellulose triacetate fiber according to any one of claims 2 to 4. 6. The method of claim 2, wherein only the cellulose diacetate component is dissolved and removed with acetone, an aqueous solution of acetone, or a mixed organic solvent containing acetone as a main component.
The method for producing cellulose triacetate fiber according to any one of claims 1 to 7.