WO2022181777A1

WO2022181777A1 - Regenerated cellulose fiber, fiber aggregates thereof, method for manufacturing viscose rayon fiber bundles, fiber bundles for artificial hair, artificial hair, and hair ornaments

Info

Publication number: WO2022181777A1
Application number: PCT/JP2022/007963
Authority: WO
Inventors: 昌平嶋田; 裕行鍛治畑
Original assignee: ダイワボウレーヨン株式会社
Priority date: 2021-02-26
Filing date: 2022-02-25
Publication date: 2022-09-01
Also published as: JPWO2022181777A1

Abstract

A regenerated cellulose fiber (A) has a fineness of 20-160 dtex, the fiber cross section has a plurality of arm portions (12, 13, 14) and constrictions (10, 11) formed by the arms, of the arm portions in the fiber cross section, at least two arm portions are arm portions a (12, 13, 14) having a length of 1.5 times or more and less than 2.5 times the width, and the fiber cross section has no arm portion having a length of 2.5 times or more the width.

Description

Regenerated cellulose fiber, fiber assembly thereof, method for producing viscose rayon fiber bundle, fiber bundle for artificial hair, artificial hair, and hair accessory

The present disclosure relates to a regenerated cellulose fiber, a fiber assembly using the same, and a method for producing a viscose rayon fiber bundle. The present disclosure also relates to fiber bundles for artificial hair, artificial hair, and hair accessories.

Regenerated cellulose fibers obtained by coagulating and regenerating a solution of dissolved cellulose by methods such as the viscose method, the cuprammonium method, and the solvent spinning method are biodegradable. Application to the application is being considered. In addition, depending on the application, it may be necessary to make the mechanical properties, shape, etc. of the regenerated cellulose fiber different from those of ordinary ones.

Viscose rayon fiber, which is one of the regenerated cellulose fibers, is made by discharging viscose, which is a water-diluted solution (alkaline) of cellulose, from a spinneret into a spinning bath (acid), and coagulating and regenerating the viscose into yarn. It is obtained by forming a thread and subjecting the thread to hot water treatment while drawing, for example. As the spinning bath, a so-called Mueller bath, which is a three-component bath of sulfuric acid-zinc sulfate-sodium sulfate, is generally used. The contact state between the viscose and the spinning bath during coagulation and regeneration of the viscose greatly affects the quality of the viscose rayon fiber obtained.

Various viscose rayon fibers with a large fineness have been proposed in the past in order to improve the rigidity of viscose rayon fibers, and various proposals have been made regarding their uses and production methods. For example, Patent Document 1 proposes an example in which 55 to 167 dtex viscose rayon fibers are applied to cleaning tools such as mops. Further, Patent Document 2 proposes a method for producing a viscose rayon fiber having a fineness of 11 dtex or more.

On the other hand, in order to improve the bulkiness of the viscose rayon fiber, various methods for producing the viscose rayon fiber by forming the cross-sectional shape into various shapes have been proposed. For example, Patent Literature 3 proposes a method of producing viscose rayon fibers by changing the shape of spinneret holes so that the obtained viscose rayon fibers have a desired cross-sectional shape. . In addition, Patent Document 4 proposes a method for producing viscose rayon fibers that develops various cross-sectional shapes by adding a modifier called a transformation agent to viscose to control the reaction of solidification regeneration. there is

For the purpose of improving rigidity, bulkiness, etc., the present applicant also proposed that the fiber cross section is irregular, and the length of the arm portion includes a constriction of 2.5 times or more the width of the arm portion, and the fineness is We have proposed a viscose rayon fiber with 40 to 160 dtex (Patent Document 5)

One of the applications of regenerated cellulose fibers is artificial hair fibers used for hair accessories such as wigs, hairpieces, braids, and hair extensions. For example, Patent Literatures 6 and 7 propose cellulosic fibers suitable for artificial hair fibers that make thinning hair inconspicuous by spraying it on thinning hair areas and fixing them with an adhesive. In addition, Patent Document 4 also proposes the use of viscose rayon fibers having the specific fiber cross-sectional shape as artificial hair. Artificial hair is provided as an artificial hair fiber bundle in which a plurality of artificial hair fibers (for example, several hundred fibers) are bundled, and is often traded in the form of a fiber bundle. is often done in

JP-A-7-23886 JP-A-8-302520 JP-A-64-45811 Japanese Patent Publication No. 44-30445 Japanese Patent No. 4546208 International Publication No. 2015/194521 pamphlet Japanese Patent Application Laid-Open No. 2001-254216

Stiffness (or flexibility), tactile feel, etc. required for viscose rayon fibers and regenerated cellulose fibers such as lyocell vary depending on the application. For example, even when applied to a cleaning tool such as a mop, different rigidity may be required depending on the material of the floor to be cleaned with the cleaning tool and the type of cleaning agent used with the cleaning tool.
As mentioned above, one of the applications of viscose rayon fibers with a fineness of about several tens of dtex is fiber for artificial hair. , sex, and the type of hair of the wearer.

An object of the present disclosure is to provide a regenerated cellulose fiber that has rigidity and feel that are different from conventional regenerated cellulose fibers.

The present disclosure is a regenerated cellulose fiber comprising:
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width does not have an arm that is 2.5 times or more of
A regenerated cellulose fiber is provided.

The present disclosure also provides a fiber bundle for artificial hair containing 20% by volume or more of regenerated cellulose fiber bundles in which a plurality of regenerated cellulose fibers are bundled, wherein the regenerated cellulose fiber bundles include regenerated cellulose fibers A having the following configuration: Provided is a fiber bundle for artificial hair containing 35% by volume or more.
(Structure of regenerated cellulose fiber A)
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width not have an arm that is 2.5 times or more of

The regenerated cellulose fiber of the present disclosure has a relatively large fineness and a specific fiber cross section, so it has moderate rigidity and flexibility. The regenerated cellulose fibers of the present disclosure can also make fiber bundles or fiber aggregates in which they are contained bulky.

In addition, since the fiber bundle for artificial hair of the present disclosure has a relatively large fineness and contains a certain amount or more of regenerated cellulose fibers having a specific fiber cross section, it is moderately rigid and has a bulkiness similar to that of human hair. Furthermore, due to the high hygroscopicity of regenerated cellulose fibers, the fiber bundles for artificial hair of the present disclosure can provide texture and feel different from those made of synthetic fibers.

1 is an optical micrograph showing a fiber cross section of a viscose rayon fiber bundle containing viscose rayon fibers of the present disclosure produced in Example 1. FIG. 4 is an optical microscope photograph showing a fiber cross section of a viscose rayon fiber bundle produced in Comparative Example 1. FIG. 2 is an optical micrograph showing a fiber cross-section of a viscose rayon fiber bundle containing viscose rayon fibers of the present disclosure produced in Example 2. FIG. 1 is a cross-sectional view schematically showing a cross section of a viscose rayon fiber according to Embodiment 1. FIG. 1 is a cross-sectional view schematically showing a cross section of viscose rayon fiber A according to Embodiment 1. FIG. FIG. 10 is an explanatory diagram showing a method for manufacturing a viscose rayon fiber bundle according to Embodiment 3;

(Circumstances leading to this disclosure)
As described above, in Patent Document 5, the present applicant has disclosed that the fiber cross section is irregular, the length of the arm portion is 2.5 times or more the width of the arm portion, and the fineness is 40 to 160 dtex. proposed a viscose rayon fiber. This viscose rayon fiber has rigidity due to its large fineness, and since the length/width ratio of the arms formed in the cross section of the fiber is relatively large, a fiber bundle or fiber aggregate containing this fiber is used. can increase the bulkiness of the

However, as described above, there are various demands for rigidity and bulkiness, and further improvement or change in properties of this viscose rayon fiber has been demanded in certain applications. For example, it has been found that the viscose rayon fiber of Patent Document 5 has relatively long arms in the fiber cross section, and such arms tend to reduce rigidity. In addition, in a fiber assembly containing this viscose rayon fiber, particularly in a fiber bundle, the fibers are likely to be entangled due to the interlocking of the arms formed in the cross section of the fiber. trended badly. These tendencies cannot be ignored, especially when the viscose rayon fiber bundles containing the viscose rayon fibers are used as artificial hair, because they affect combability, and have improved rigidity and splitting properties. A viscose rayon fiber that provides a good fiber bundle is desired.

Therefore, the present inventors thought that the stiffness and splittability could be improved by controlling the length/width ratio of the arms to be smaller than the value proposed in Patent Document 5.
As mentioned above, viscose rayon fiber is made from natural cellulose such as wood pulp. It is treated with alkali (caustic soda) and then reacted with carbon disulfide to create a cellulose derivative. A wet process that regenerates cellulose by extruding this undiluted solution into a spinning bath or an acid bath called a coagulation bath through the nozzle hole of a spinneret (also called a nozzle hole), causing a chemical reaction while forming fibers. Manufactured by the spinning method. In this spinning process, the shape of the cross-section of the resulting fiber tends to change depending on how the solvent is "extracted" from the fiber during spinning. For example, viscose rayon fibers, which are widely used for clothing and sanitary goods, have a chrysanthemum-shaped fiber cross section with fine unevenness on the outer edge instead of a circular cross section. The mechanism by which the fine unevenness is formed is thought to be as follows. The viscose extruded from the spinneret hole immediately solidifies to form a surface layer (also referred to as a skin layer), dewatered from the viscose through this layer, and the inside is coagulated and regenerated and solidified. At that time, it is thought that fine irregularities are formed as the volume decreases due to shrinkage.

Patent Document 5 discloses that the length/width ratio is 2.5 or more by making the take-up direction of the spun yarn discharged from the nozzle hole of the spinneret oblique to the bath surface of the spinning bath. It allows coagulation regeneration and dehydration such that arms are formed. However, according to the inventors' investigation, this method cannot control the fiber cross section any more, and the viscose rayon fiber with a fiber cross section having arms with a short length/width ratio can be stably I couldn't get it.

In this way, the cross-sectional shape of viscose rayon fibers is affected by coagulation regeneration and dehydration, making it difficult to control and designing the cross-section of viscose rayon fibers is not easy. The present inventors further studied the spinning conditions and found the conditions under which a viscose rayon fiber having a plurality of arms with a length/width ratio of 1.5 or more and less than 2.5 can be produced, leading to the present disclosure. . Furthermore, the present inventors have found that the fiber cross section of the viscose rayon fiber produced by this method is obtained by a method other than the viscose method, such as regenerated cellulose fiber (lyocell) obtained by a solvent spinning method or a cuprammonium method. It has been found that the regenerated cellulose fiber (cupra) can also be realized by adjusting the shape of the spinneret.

The regenerated cellulose fibers of the present disclosure are
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width does not have an arm that is 2.5 times or more of
It is a regenerated cellulose fiber. As will be described later, this regenerated cellulose fiber is produced to be contained in a fiber bundle composed of regenerated cellulose fiber, and the fiber bundle may contain regenerated cellulose fiber other than this regenerated cellulose fiber. Therefore, in the following description, the regenerated cellulose fiber having the specific fiber cross-sectional shape is referred to as "regenerated cellulose fiber A" (a specific type of fiber is referred to by adding A to the type name), and the specific fiber It is distinguished from regenerated cellulose fibers that do not have a cross-sectional shape. Hereinafter, the regenerated cellulose fiber A will be described as Embodiment 1.

[Embodiment 1: Regenerated cellulose fiber A]

The regenerated cellulose fiber A has a fineness of 20 dtex or more and 160 dtex or less, for example, 40 dtex or more and 160 dtex or less, particularly 45 dtex or more and 120 dtex or less, more particularly 50 dtex or more and 80 dtex or less. If the fineness is less than 20 dtex, sufficient rigidity may not be obtained. On the other hand, when the fineness exceeds 160 dtex, the fiber diameter is too large, which may make handling difficult. Further, when the regenerated cellulose fiber A is used as a fiber for artificial hair, the fineness affects the feel and appearance, and if the fineness is outside this range, the feel and appearance may become unnatural.

The fiber cross section of the regenerated cellulose fiber A has a plurality of arms and constrictions formed by the arms, and the length of the arms is 1.5 times or more and less than 2.5 times the width. has at least two, i.e., multiple formed shapes. Due to this specific fiber cross section, in the fiber bundle containing the regenerated cellulose fibers A, between the regenerated cellulose fibers A and / or between the regenerated cellulose fibers A and other fibers (which may be fibers other than regenerated cellulose fibers) A reasonable gap can be maintained between When the regenerated cellulose fibers A are used as fibers for artificial hair, the gaps created by the regenerated cellulose fibers A can impart a voluminous feel close to that of human hair.

Here, an example of an embodiment of the regenerated cellulose fiber A and how to determine the length and width of the arms will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a fiber cross section of viscose rayon fiber A as regenerated cellulose fiber A. FIG. In FIG. 2, the cross section of the fiber is not hatched for the sake of convenience of explanation to be described later.

In FIG. 2, 10 and 11 are constrictions, the constriction 10 being formed by two

arms

12,13 and the constriction 11 being formed by two

arms

13,14.

The arm 14 will be used as an example to explain how to determine the length and width of the arm. As shown in FIG. 2, first, a line segment 15 connects

points

14a, 14a where the radius of curvature is the smallest in the curves of the two skirt portions of the arm portion 14. As shown in FIG. Next, a line segment 16 connects a point 15 a that bisects the length of the line segment 15 to the top 14 b of the arm portion 14 . Next, a line segment 17 is constructed by cutting the perpendicular bisector of the line segment 16 with the arm portion 14 . A point 17a that bisects the length of the line segment 17 is obtained, and a line segment 18 connecting the

points

15a and 17a and a line segment 19 connecting the

points

17a and 14b are drawn. Then, the lengths of the line segment 18 and the line segment 19 are measured, and the total value thereof is taken as the length of the arm portion 14 . Also, a line segment 20 obtained by cutting the perpendicular bisector of the line segment 18 with the arm 14 and a line segment 21 obtained by cutting the perpendicular bisector of the line segment 19 with the arm 14 are constructed. . Then, the lengths of the

line segments

15, 17, 20, and 21 are measured, and the average value thereof is taken as the width of the arm portion 14. FIG.

In the present embodiment, the fiber cross section of the regenerated cellulose fiber A has a length measured by the above method that is 1.5 times or more and less than 2.5 times the width measured by the above method (i.e., length/width ratio is 1.5 or more and less than 2.5). The term "arm a" is used herein to distinguish arms having a length/width ratio of less than 1.5 or greater than or equal to 2.5. The regenerated cellulose fiber A has a plurality of arm portions a in its fiber cross section, so that when this fiber is included in a fiber assembly (for example, a fiber bundle), it can impart appropriate bulkiness to the fiber assembly. can.

The regenerated cellulose fiber A has at least two arms a, and may have three or more in particular. The number of arms a may be five or less. As the number of arm portions a increases in the regenerated cellulose fiber A with a certain fineness, the width of the arm portions a becomes narrower, and it tends to be difficult to form such arm portions a. In addition, the number of arms including the arm a is also affected by the fineness of the regenerated cellulose fiber A. For example, regenerated cellulose fibers with a fineness of about 50 dtex (particularly viscose rayon fiber A) tend to have two or three arms a when produced by the method described later. The number of parts a also tends to increase.

The arm a having a length/width ratio of 1.5 or more and less than 2.5, the arm a1 having a length/width ratio of 1.5 or more and less than 2, and the arm a1 having a length/width ratio of 2 or more and less than 2 0.5 or less, the ratio (a1/a2) of both numbers in the regenerated cellulose fiber A is preferably 0.1 or more, more preferably 1 or more. Although the upper limit is not limited, it is preferably 9 or less, more preferably 7 or less. When a1/a2 is within the above range, for example, a fiber bundle containing the regenerated cellulose fiber A can have bulkiness and splitting properties similar to those of human hair. Alternatively, all arms a may be arms a1, or all arms a2.

An arm portion other than the arm portion a (that is, an arm portion having a length/width ratio not less than 1.5 and less than 2.5) may be formed in the fiber cross section of the regenerated cellulose fiber A. However, in the fiber cross section of the regenerated cellulose fiber A of the present embodiment, relatively long arms having a length/width ratio of 2.5 or more are not formed. If an arm having a length/width ratio of 2.5 or more is formed, the rigidity of the regenerated cellulose fiber A may not be sufficient, and the entanglement of the fibers tends to occur, resulting in separation property. tend to be unsuitable for applications where importance is placed on (for example, artificial hair).

In the regenerated cellulose fiber A of the present embodiment, as an arm other than the arm a, the arm b whose length is 1 time or more and less than 1.5 times the width (the symbol "b" is distinguished from the arm a) ) may be formed. In the regenerated cellulose fiber A of the present embodiment, the number of arm portions b is preferably four or less, particularly three or less, and more particularly two or less. When the arm portion b having a length/width ratio of 1 to 1.5 times exists in the cross section of the fiber, adhesion between the fibers tends to be more suppressed than when the arm portion does not include the arm portion. If many arms b are included, the number of arms a decreases, and the number of arms a may not be plural.
The ratio (b/a) of the number of arms b and arms a is preferably 0 to 0.5. It is more preferably 0 to 0.4, and even more preferably 0 to 0.3.

Alternatively, the regenerated cellulose fiber A may have no arms other than the arms a, and may have only the arms a. According to such regenerated cellulose fiber A, while increasing the bulkiness of the fiber assembly to some extent, the fiber separation property can be appropriately improved. can be close.

The fiber cross section shown in FIG. 1 is an E-shape having three

arms

12, 13, 14 and two

constrictions

10, 11, and the three

arms

12, 13, 14 are all arm a. The fiber cross section of the regenerated cellulose fibers A is not limited to the illustrated one, and may be any shape such as Y-shape, W-shape, F-shape, X-shape, H-shape, and n-shape. . For example, when the fiber cross section of the regenerated cellulose fiber A is n-shaped, it will have two arms and one constriction, and both of the two arms will be the arms a.

In the regenerated cellulose fiber A of this embodiment, the arm portion a may have a "medium thick" shape. Here, whether or not the arm a has a “medium thick” shape is determined by measuring the length/width ratio of the arm a having a length/width ratio of 1.5 or more and less than 2.5 at approximately the center of the arm in FIG. When the length of the corresponding line segment 17 and the length of the line segment 15 corresponding to the approximate root portion or the length of the line segment 20 at approximately a quarter of the position from the approximate root portion are measured, and the length of the line segment 17 is set to 1 is determined by calculating the length of the

line segment

15 or 20 of When the length of the

line segment

15 or 20 is less than 1 when the length of the line segment 17 is 1, the arm has a medium-thick shape.

Among the regenerated cellulose fibers A having at least two arms a, the proportion of fibers having at least two arms a having a medium-thickness shape may be, for example, 25% by volume or more, particularly 40% by volume or more. and more particularly 50% by volume or more. A fiber having at least two medium-sized arms a has an appearance closer to that of a hollow shape. Therefore, a fiber bundle containing such fibers tends to be bulkier, or tends to trap liquids or the like more easily inside the fibers, that is, tends to be more improved in liquid retention.

Alternatively or additionally, in the regenerated cellulose fiber A of the present embodiment, the arms a may have a bent shape. Whether or not the arm a is bent is determined by the point 17a that bisects the line segment 17 in FIG. 3 and the line segment Determined by measuring the angle (acute angle, θ in FIG. 3) formed by a line segment 18 connecting the point 15a that bisects the length of 15 and a line segment 19 connecting the point 17a and the top 14b of the arm. do. The method of obtaining the

line segments

17, 18, and 19 is as described above with reference to FIG. If the angle is greater than or equal to 45°, the arm shall have a bent shape.

Among the regenerated cellulose fibers A having at least two arms a, the proportion of fibers having at least one arm a having a bent shape may be, for example, 25% by volume or more, particularly 40% by volume or more. and more particularly 50% by volume or more. A fiber having at least two arms a having a bent shape has an appearance closer to a hollow shape, and this tendency becomes stronger as the number of arms a having a bent shape increases. Therefore, a fiber bundle containing such fibers tends to be bulky, or tends to trap liquids and the like inside the fibers, that is, tend to have improved retention of liquids and the like.

In this embodiment, the regenerated cellulose fiber A has a plurality of arms, and therefore has one or more constrictions. The constriction becomes a portion capable of holding liquid or minute solids (including semi-solids). Therefore, when the regenerated cellulose fiber A (or a fiber assembly containing it) is applied to a cleaning tool such as a mop, fine dust can be caught in the constriction, or when a liquid detergent is used, can hold the detergent. In addition, when applied to fibers for artificial hair, it is possible to retain a liquid type or wax type styling agent, and it is possible to provide artificial hair that can be styled with the styling agent.

One or more constrictions may be formed in the fiber cross section of the regenerated cellulose fibers A. The greater the number of constrictions, the greater the number of arms, which tends to improve liquid retention and bulkiness. Specifically, the number of constrictions may be, for example, one or more and four or less, and particularly one or more and three or less. The number of constrictions tends to increase as the fineness of the regenerated cellulose fibers A increases.

In the fiber cross section of the regenerated cellulose fiber A, the width of the arm portion a may be 5 µm or more and 50 µm or less, particularly 10 µm or more and 40 µm or less, and more particularly 15 µm or more and 30 µm or less. If it is attempted to obtain the arm portion a having a width of less than 5 μm, it may become difficult to mold the regenerated cellulose fibers. On the other hand, if the width of the arm portion a exceeds 50 μm, the constriction tends to become small, making it difficult to form the arm portion a, and it may be difficult to retain liquids and fine solids in the fibers.

In the fiber cross section of the regenerated cellulose fiber A, the length of the arm portion a may be 20 m or more and 60 μm or less, particularly 22 μm or more and 50 μm or less. More particularly, it may be 25 μm or more and 45 μm or less. If an attempt is made to obtain an arm portion a having a length of less than 20 μm, the constriction tends to become smaller, making it difficult to form the arm portion a, and it may be difficult to retain liquids and fine solids in the fiber. . On the other hand, when the length of the arm portion a exceeds 50 μm, the rigidity of the regenerated cellulose fiber A may not be sufficient, and the entanglement of the fibers is likely to occur, resulting in applications where separation is important (for example, , artificial hair).

The regenerated cellulose fibers may be viscose rayon fibers, solvent-spun cellulose fibers (lyocell), regenerated cellulose fibers obtained by the cuprammonium method (cupra).
Viscose rayon fibers are obtained by coagulating and regenerating viscose, which is a water-diluted solution (alkaline) of cellulose. The viscose is not particularly limited, and those having a composition used for producing conventional viscose rayon fibers can be used. For example, viscose containing 8.0 to 9.5% by mass of cellulose, 5.0% to 6.5% by mass of sodium hydroxide, and 2% to 4% by mass of carbon disulfide can be used. A lyocell fiber is obtained by solidifying a spinning stock solution in which cellulose is dissolved in an aqueous solution of N-methylmorpholine-N-oxide (NMMO) as a solvent. A cupra fiber is obtained by wet-spinning a spinning dope obtained by dissolving 9 to 12% by mass of cellulose such as cotton linter or pulp in a cuprammonium solution (Schweitzer solution).

When the regenerated cellulose fibers are viscose rayon fibers, the regenerated cellulose fibers A have an irregular fiber cross section. When the regenerated cellulose fibers are lyocell fibers or cupro fibers, the regenerated cellulose fibers A tend to have a relatively uniform fiber cross-section due to their manufacturing method.

Regenerated cellulose fiber A contains an ultraviolet absorber, an infrared absorber, a fluorescent whitening agent, a release agent, a lubricant, an antibacterial agent, a nucleating agent, a heat stabilizer, an antioxidant, an antistatic agent, an anti-coloring agent, and a regulator. , matting agents, deodorants, defoamers, colorants, flame retardants, yarn friction reducing agents, preservatives, gelling agents, latexes, fillers, inks, colorants, dyes, pigments, fragrances , may contain one or more additives. These additives may be contained in fibers other than the regenerated cellulose fibers A in the fiber assembly described later.

[Embodiment 2: Fiber assembly]
The fiber assembly of the present disclosure contains the regenerated cellulose fibers A described above. This fiber assembly will be described below as a second embodiment.

As will be described later, when the regenerated cellulose fiber A is a viscose rayon fiber A, the viscose rayon fiber A has the above specific fiber cross section by selecting wet spinning conditions. On the other hand, even fibers discharged from a common spinneret into the same spinning bath at the same time may not have a fiber cross section having an arm a due to local variations in spinning conditions. In that case, the viscose rayon fiber A constitutes a fiber bundle together with other viscose rayon fibers (the fiber cross section does not have the arm part a, or if it does have one arm part), and is spun and taken. It will happen. It is generally difficult to select and use only the viscose rayon fiber A from this fiber bundle. This may also be true for Cupra A, which is produced by the cuprammonium method, and Lyocell fiber A, which is produced by the solvent spinning method. Therefore, in the present embodiment, the ratio of the regenerated cellulose fibers A in the fiber assembly (regenerated cellulose fiber assembly) made of regenerated cellulose fibers is specified, and the fiber assembly containing the regenerated cellulose fiber assembly at a predetermined ratio or more explain.

More specifically, the regenerated cellulose fiber aggregate of the present embodiment has a proportion of regenerated cellulose fibers A of 35% by volume or more. If the proportion of the regenerated cellulose fibers A is less than 35% by volume, the bulkiness of the regenerated cellulose fiber assembly may be insufficient, and in particular, the fiber bundle may become too soft. The proportion of the regenerated cellulose fibers A in the regenerated cellulose fiber assembly may be particularly 45% by volume or more, more particularly 60% by volume or more, and even more particularly 80% by volume or more. The greater the ratio of the regenerated cellulose fibers A in the regenerated cellulose fiber assembly, the more the effects (improved bulkiness and rigidity, etc.) of the inclusion of the regenerated cellulose fibers A are exhibited.

The regenerated cellulose fiber aggregate may be in the form of a fiber bundle (also called "tow"), or may be an aggregate of short fibers obtained by cutting a fiber bundle into a certain length. Bundles of fibers and staple fibers can be used as materials such as spun yarns, woven fabrics, knitted fabrics, non-woven fabrics, or paper. Alternatively, the fiber assembly of this embodiment may be a woven fabric, knitted fabric, non-woven fabric, paper, or the like.

As long as the regenerated cellulose fibers A contained in the regenerated cellulose fiber aggregate are those described in the first embodiment, they do not all need to be the same. For example, the regenerated cellulose fibers A of the fiber assembly may have different shapes, and the dimensions and number of arms a and the number of constrictions may differ from each other. In addition, the fiber assembly may contain regenerated cellulose fibers A having different finenesses.

The regenerated cellulose fiber assembly of the present embodiment may contain regenerated cellulose fibers other than the regenerated cellulose fibers A, as long as the regenerated cellulose fibers A are contained in a certain proportion or more with respect to the total volume of the regenerated cellulose fibers. . For example, a regenerated cellulose fiber other than the regenerated cellulose fiber A does not have an arm portion a in its fiber cross section, and has only an arm portion b whose length/width ratio is 1 time or more and less than 1.5 times. can be The regenerated cellulose fiber having only the arm portion b is, for example, 65% by volume or less, particularly 55% by volume or less, more particularly 40% by volume, relative to the total volume of the regenerated cellulose fiber (total volume of each regenerated cellulose fiber). % or less.

The average width of the arms a of the regenerated cellulose fibers A contained in the 30 regenerated cellulose fibers arbitrarily selected from the regenerated cellulose fiber assembly of the present embodiment may be 5 μm or more and 50 μm or less. The average width of the arm portion a may be particularly 10 μm or more and 40 μm or less, more particularly 15 μm or more and 30 μm or less. When the average value of the widths of the arm portions a of the regenerated cellulose fibers A in the fiber assembly is within the above range, even if the regenerated cellulose fibers A having the arm portions a whose width is outside the above range are included, the overall , the same effect as when the width of the arm portion a of each regenerated cellulose fiber A is within the above range can be exhibited.

In addition, the average value of the lengths of the arm portions a of the 30 regenerated cellulose fibers A arbitrarily selected from the regenerated cellulose fiber assembly of the present embodiment may be 20 m or more and 60 μm or less. The average value of the length of the arm a may be particularly 22 μm or more and 50 μm or less, more particularly 25 μm or more and 45 μm or less. If the average value of the lengths of the arm portions a of the regenerated cellulose fibers A in the fiber assembly is within the above range, even if the regenerated cellulose fibers A having arm portions a whose length is outside the above range are included. As a whole, the same effect as when the length of the arm portion a of each regenerated cellulose fiber A is within the above range can be exhibited.

The regenerated cellulose fiber assembly of the present embodiment may form another fiber assembly (hereinafter also referred to as "fiber assembly S" to distinguish it from the regenerated cellulose fiber assembly) together with other fibers. In that case, the ratio of the regenerated cellulose fiber aggregates of the present embodiment to the fiber aggregates S may be 20% by volume or more, particularly 40% by volume or more, and more particularly 60% by volume or more. If the ratio of the regenerated cellulose fiber aggregates of the present embodiment is small, the absolute amount of the regenerated cellulose fibers A is also small, and the effect of the regenerated cellulose fibers A may not be obtained in the fiber aggregates S.

The other fibers contained in the fiber assembly S may be synthetic fibers, other cellulosic fibers, or natural fibers.

When the regenerated cellulose fiber aggregate of the present embodiment is an aggregate of short fibers obtained by cutting regenerated cellulose fiber bundles, for example, those having a fiber length of 1 mm or less can be used as a blasting material for deburring circuit boards. can be used. For example, short fibers having a fiber length of 0.1 to 3 mm can be used as a resin kneading material for patterning plastic moldings. The same applies when the fiber aggregate S is an aggregate of short fibers.

When the regenerated cellulose fiber assembly of the present embodiment is a regenerated cellulose fiber bundle, the fiber bundle may be cut into an appropriate length to form a mop for cleaning tools. Alternatively, the fiber assembly of the present embodiment may be provided as filters, civil engineering materials (nets, cheesecloth, sandbags, curing mats), spun yarns used for crisp clothing, sponges for bathing, and the like. , or may be provided as these raw materials. In particular, for civil engineering materials, products that have the property of being decomposed by microorganisms in the soil (biodegradability) after being used for a certain number of years are sometimes desired. A body is preferably used. This is because regenerated cellulose fibers are biodegradable. From the viewpoint of environmental protection, biodegradability is being sought for various uses other than civil engineering materials, and the fiber assembly of the present embodiment is also preferably used for those uses.
The same applies when the fiber assembly S is a fiber bundle.

[Embodiment 3: Fiber bundle for artificial hair]
Alternatively, the regenerated cellulose fiber assembly of the present embodiment or the fiber assembly S containing the same may be used as a material for artificial hair for hair accessories, that is, as a fiber bundle for artificial hair. Hereinafter, a fiber bundle for artificial hair will be described as Embodiment 3. The fiber bundle for artificial hair of this embodiment is a fiber bundle for artificial hair containing 20% by volume or more of regenerated cellulose fiber bundles in which a plurality of regenerated cellulose fibers are bundled. It contains 35% by volume or more of the regenerated cellulose fiber A described above. The regenerated cellulose fiber bundle contained in the fiber bundle for artificial hair may contain the regenerated cellulose fiber A in an amount of 45% by volume or more, more particularly 60% by volume or more. The greater the ratio of the regenerated cellulose fibers A in the regenerated cellulose fiber bundle, the more the effect (improvement in bulkiness and rigidity, etc.) due to the inclusion of the regenerated cellulose fibers A is exhibited.

As in Embodiment 2, the regenerated cellulose fibers A contained in the fiber bundle for artificial hair of this embodiment need not be all the same as long as they are those described in Embodiment 1. For example, the regenerated cellulose fibers A in the fiber bundle for artificial hair may have different shapes, and the dimensions and number of arms a and the number of constrictions may differ from each other. In addition, the fiber bundles for artificial hair may contain regenerated cellulose fibers A having different finenesses.

When the fiber bundle for artificial hair of this embodiment is produced by the method described as Embodiment 4, the fiber bundle is a regenerated cellulose fiber bundle itself spun from a spinneret having a plurality of nozzles, or this bundle is Supplied in combination with fiber bundles. For example, when the regenerated cellulose fiber is a viscose rayon fiber, the viscose rayon fiber A has the above specific fiber cross section by selecting wet spinning conditions. On the other hand, even fibers discharged from a common spinneret into the same spinning bath at the same time may not have a fiber cross section having an arm a due to local variations in spinning conditions. The fiber bundle of the present embodiment contains regenerated cellulose fibers in which arm portions a are not formed in the cross section of the fibers due to local changes in the spinning conditions, as long as the regenerated cellulose fibers A are contained in a certain proportion or more. good. For example, the regenerated cellulose fibers other than the regenerated cellulose fiber A contained in the regenerated cellulose fiber bundle do not have, for example, an arm portion a in the fiber cross section, and have an arm portion with a length/width ratio of less than 1.5. can be anything. The regenerated cellulose fiber having such arms may be contained in the regenerated cellulose fiber bundle in a proportion of, for example, 65% by volume or less, particularly 55% by volume or less, and more particularly 40% by volume or less.

The fiber bundle for artificial hair of the present embodiment may contain fibers other than regenerated cellulose fibers (hereinafter, "other fibers") as long as it contains 20% by volume or more of the regenerated cellulose fiber bundles described above. Other fibers may be synthetic fibers, other cellulosic fibers, natural fibers, or human hair. For example, acrylic fibers are preferable as synthetic fibers.

The length of the fiber bundle for artificial hair is not particularly limited, and it has a length suitable for processing the hair accessory according to the type and design of the hair accessory using it. Alternatively, fiber bundles may be provided having lengths on the order of several meters. In that case, the fiber bundle may be cut to have a desired length when manufacturing the hair accessory.

Since the fiber bundle for artificial hair contains a regenerated cellulose fiber bundle containing regenerated cellulose fiber A at a predetermined ratio or more, the inherent properties of the regenerated cellulose fiber impart excellent properties to the hair accessory. For example, human hair is hygroscopic, and its moisture content changes depending on the surrounding environment, etc., and the change in moisture content affects the feel of the touch. The cross-sectional shape of the cellulose fiber A and the water absorbency of the cellulose fiber A combine to make the texture of the fiber bundle closer to that of human hair. Moreover, since the regenerated cellulose fibers do not melt even when heated, the fiber bundle of the present embodiment can be provided as one that can be styled with a dryer, an iron, or the like. Furthermore, since the regenerated cellulose fiber is difficult to be charged, it is possible to suppress the generation of static electricity in the hair accessory.

Furthermore, since the regenerated cellulose fibers are biodegradable, the artificial hair fiber bundles of the present embodiment can compare the load on the environment when discarded after use with that of the artificial hair fiber bundles made only of synthetic fibers. can be made smaller.

Therefore, this embodiment is suitable for use as artificial hair for hair accessories such as wigs (including partial wigs and full wigs), hairpieces, braids, and extension hair. The hair part of the hair accessory using this material exhibits a touch feeling, rigidity, and combability similar to those of human hair, and the wearer and those who come in contact with the wearer are less likely to feel discomfort.

Furthermore, the artificial hair fiber bundle of the present embodiment includes dolls (for toys, ornamental use, commercial use (mannequins, etc.), education/training uses, experiments (dummy dolls, etc.), and explanations in museums and archives. ) may be used to make hair. According to this embodiment, the thickness of the regenerated cellulose fibers A constituting the fiber bundle for artificial hair can be selected according to the size or scale of the doll. Avoid or reduce unnatural appearance.

[Embodiment 4: Method for producing a fiber bundle]
Next, a method for producing a fiber bundle including viscose rayon fibers A as regenerated cellulose fibers A and a bundle of a plurality of viscose rayon fibers will be described as a fourth embodiment.
In the production of viscose rayon fibers, viscose is discharged into a spinning bath from a plurality of spinneret holes provided in a spinneret, and the viscose is solidified and regenerated to form a fiber bundle, and this fiber bundle is spun. The production method of the present embodiment includes taking-up by a take-up roller provided outside the bath, and the manufacturing method of the present embodiment sets the spinning conditions to predetermined ones so that the fiber bundle contains viscose rayon fibers A in a certain proportion or more. I have secured.

The viscose used in the present embodiment is not particularly limited, and may have a composition that is used when producing conventional viscose rayon fibers. The spinning bath is also not particularly limited, and a general acidic spinning bath can be used. For example, a Mueller bath containing 110 to 170 g/liter of sulfuric acid, 10 to 30 g/liter of zinc sulfate, and 150 to 350 g/liter of sodium sulfate can be used. The temperature of the spinning bath may be, for example, between 45°C and 65°C, in particular between 53°C and 58°C. If the temperature of the spinning bath is lower than 45° C., the viscose may become difficult to solidify and regenerate, and the fibers may stick to each other. On the other hand, if the temperature of the spinning bath exceeds 65° C., coagulation regeneration may proceed excessively, and excessive force may be applied during drawing, resulting in fiber breakage.

In the manufacturing method of the present embodiment, the value of V ₂ _{/V 1} ₍ _hereinafter referred to as “Jet (referred to as "draft rate") of 0.5 to 1.5, especially 0.8 to 1.4. By setting the Jet Draft ratio to 0.5 to 1.5, even when the angle formed by the drawing direction of the fiber bundle and the bath surface of the spinning bath is approximately perpendicular as described later, the tension applied to the fiber is relaxed. The way in which the solvent (generally water) is removed from the inside of the fiber (dehydration) and the speed of coagulation regeneration can give the cross section of the fiber the shape described in the first embodiment. More specifically, by relaxing the tension applied to the fiber bundle, the fibers immediately after spinning become slightly swollen, and the circumference of the fiber cross section becomes longer. It is thought that it contributes to the coagulation regeneration and dehydration of the epidermal layer, which is different from the spinning of the

If the Jet Draft ratio is less than 0.5, the tension applied to the yarn at the exit of the spinneret hole becomes weak, and the fibers may stick to each other. On the other hand, when the Jet Draft ratio exceeds 1.5, the tension applied to the fiber at the exit of the spinneret hole increases, making it difficult to obtain a desired fiber cross section.

In this embodiment, spinning is performed using a spinneret provided with a plurality of spinneret holes. The mouthpiece hole has, for example, a hole diameter of 0.15 mm or more and 0.5 mm or less, particularly a hole diameter of 0.2 mm or more and 0.48 mm or less, and more particularly a hole diameter of 0.3 mm or more and 0.45 mm or less. If the pore diameter is less than 0.15 mm, the viscose discharge speed tends to be too high and the Jet Draft ratio tends to be too small. On the other hand, if the pore size exceeds 0.5 mm, the viscose discharge speed tends to be slow and the Jet Draft ratio tends to be too large.

The cross section of the mouthpiece hole in the radial direction may be a perfect circle or an ellipse. In addition, when the said cross section is an ellipse, the said hole diameter points out the length|longer_axis of the said ellipse. Moreover, when the cross section is an ellipse, the minor axis of the ellipse may be, for example, 0.1 mm or more and 0.4 mm or less.

In the manufacturing method of the present embodiment, when the viscose rayon fiber bundle is taken up by the take-up roller, the take-up direction of the spun yarn located substantially at the center of the fiber bundle in the spinning bath and the bath surface of the spinning bath form. Pick up is performed so that the angle is 80° or more and 110° or less. This angle range means that the take-up direction of the viscose rayon fiber bundle is substantially perpendicular to the bath surface of the spinning bath. The spun yarn positioned substantially at the center of the fiber bundle is a yarn spun from a spinneret hole positioned substantially at the center among a plurality of spinneret holes formed in the spinneret. The direction of the yarn spun from the spinneret hole is determined by the positional relationship between the spinneret and the take-up roller. Adjust the angle between the line and the bath surface.

Making the take-up direction of the viscose rayon fiber bundles substantially perpendicular to the bath surface of the spinning bath is generally adopted in the production of viscose rayon, which is widely used for clothing applications. When the viscose rayon fiber bundle is taken out so that it is almost perpendicular to the bath surface, the removal of the viscose solvent is compared as if a chrysanthemum-shaped fiber cross section with fine irregularities formed on the outer edge is obtained. tend to progress uniformly. In this embodiment, as described above, the tension applied to the fibers is relaxed with the Jet Draft ratio set to a specific range, so that even when the fiber bundle is drawn in a direction substantially perpendicular to the bath surface of the spinning bath, A viscose rayon having a specific fiber cross section different from the chrysanthemum-shaped cross section of general-purpose viscose rayon fiber by adjusting the regeneration speed of the formed skin layer and the unevenness formed by dehydration shrinkage. Fiber A is obtained.

In the production method of the present embodiment, the take-up speed of the yarn by the take-up roller may be 10 m/min or more and 60 m/min or less, particularly 20 m/min or more and 40 m/min or less. If the take-up speed is less than 10 m/min, productivity may decrease. On the other hand, if the take-up speed exceeds 60 m/min, the residence time of the yarn in the spinning bath is shortened, so that the viscose rayon fiber A cannot be obtained, or the proportion of the viscose rayon fiber A in the fiber bundle is small. can be. The residence time of the fiber bundle in the spinning bath may be, for example, 0.4 to 2.4 seconds, in particular 0.6 to 1.2 seconds. A short residence time may result in insufficient coagulation regeneration.

In order to make the residence time in the spinning bath sufficient, in this embodiment, the spinneret (more specifically, the discharge surface of the spinneret) of the spun yarn located at the center of the viscose rayon fiber bundle and the The length between the bath surface of the spinning bath may be 400 mm or more. That is, the solvent remains in the fiber even when the solvent is removed more unevenly by making the spinning bath deeper and allowing the contact time between the viscose rayon fiber bundles and the spinning bath to be longer. It is possible to prevent this and to make the viscose coagulation regeneration sufficient. The length of the viscose rayon fiber bundle between the spinneret and the bath surface of said spinning bath may in particular be greater than or equal to 450 mm. The upper limit of the length of the slivers between the spinneret and the surface of the spinning bath may be, for example, 550 mm, in particular 500 mm.

The manufacturing method of the present embodiment may include drawing the viscose rayon fiber bundle after the viscose rayon fiber bundle is drawn by the take-up roller. In that case, the draw ratio of the fiber bundle from the take-up roller to the final roller may be, for example, 20% or more and 50% or less. If the draw ratio is less than 20%, the orientation of the regenerated cellulose constituting the viscose rayon fiber A is lowered, and the rigid viscose rayon fiber A may not be obtained. On the other hand, if the draw ratio exceeds 50%, the fibers may be cut during drawing. When the viscose rayon fiber bundle is drawn, if the take-up speed of the fiber bundle by the take-up roller is 20 m/min or more and 40 m/min or less, the winding speed of the final roller is, for example, 24 m/min or more and 60 m/min. It can be:

In the manufacturing method of the present embodiment, viscose is discharged simultaneously from spinning nozzles provided with a plurality of spinneret holes to manufacture viscose rayon fiber bundles. Therefore, due to the influence of the position of the spinneret hole, the temperature in the spinning bath, etc., the arm part a having a predetermined length/width ratio value is not formed in the fiber cross section of some fibers, and the fiber bundle is viscose. Viscose rayon fibers other than rayon fiber A may be included. Even in that case, according to the production method of the present embodiment, a viscose rayon fiber bundle containing a certain amount of viscose rayon fiber A (for example, 35% by volume or more) is obtained, and a fiber assembly produced using this viscose rayon fiber bundle , the effect of the viscose rayon fiber A is exhibited. Therefore, the manufacturing method of the present embodiment may include viscose rayon fibers other than the viscose rayon fibers A in the finally obtained viscose rayon fiber bundle.

FIG. 4 shows an explanatory view schematically showing the viscose rayon fiber bundle manufacturing method in this embodiment. As shown in FIG. 4, in the manufacturing method of the present embodiment, viscose is discharged into the spinning bath 30 through the spinneret holes of a spinneret 31 provided in the spinning bath 30 to solidify and regenerate the viscose. In this method, a viscose rayon fiber bundle 32 is formed, and the fiber bundle 32 is taken up by a take-up roller 33 provided outside a spinning bath 30 to produce a viscose rayon fiber.

The mouthpiece hole has a hole diameter of, for example, 0.15 mm or more and 0.5 mm or less. Further, the Jet Draft ratio when the viscose rayon fiber bundle 32 is taken by the take-up roller 33 is 0.5 or more and 1.5 or less. Of the viscose rayon fiber bundles 32 in the spinning bath 30, the angle θ between the spun yarn 32a discharged from the spinneret hole provided substantially at the center of the spinneret and the bath surface 30a of the spinning bath 30 is 80°. 110° or less, and the fiber bundle 32 is picked up so as to be substantially orthogonal to the bath surface 30a. At this time, the distance L ₁ between the approximate center of the discharge surface of the spinneret 31 and the bath surface 30a (the distance from the spinneret to the bath surface of the spun yarn positioned approximately at the center of the viscose rayon fiber bundle being spun) (corresponding to the length) may be 400 mm or more and 600 mm or less, and the distance between the bath surface 30a and the take-up roller 33 may be 150 mm or more and 300 mm or less. The fiber bundle 32 taken by the take-up roller 33 is stretched by, for example, a stretching roller (not shown).

The production method of the present embodiment may further include, after obtaining the viscose rayon fiber bundle by the method described above, appropriately subjecting it to a treatment that is performed when producing ordinary viscose rayon fibers. For example, a viscose rayon fiber bundle may be cut to length. Also, the fiber bundle may be subjected to a drying treatment after spinning. The viscose rayon fiber bundle may also be subjected to a dyeing treatment.

In the production method of the present embodiment, a plurality of spinnerets are arranged in the spinning bath, viscose rayon fiber bundles are pulled from each spinneret under the above conditions and drawn, and then these fiber bundles are combined to form one viscose. A rayon fiber bundle may be used.

A lyocell fiber bundle is produced by passing a spinning stock solution discharged from a spinning nozzle provided with a plurality of spinneret holes through an air gap section and immersing it in a coagulation bath. A lyocell fiber bundle containing the lyocell fiber A is obtained by using a spinneret having a spinneret hole having a shape corresponding to a fiber cross section having at least two arms a, or a shape capable of obtaining such a fiber cross section. be done. The fiber cross-sectional shape of the lyocell fibers tends to more closely match the shape of the spinneret hole. Therefore, in the production of the lyocell fiber bundle, spinneret holes corresponding to the cross-sectional shape of the fiber to be obtained are selected, taking into consideration the change in shape caused by other conditions during spinning.

A cupro fiber bundle is obtained by coagulating a spinning dope discharged into a spinning funnel from a spinning nozzle provided with a plurality of spinneret holes with a coagulating liquid and then regenerating it in a sulfuric acid bath. A cupro fiber bundle containing the cupra fiber A is obtained by using a spinneret provided with a spinneret hole having a shape corresponding to a fiber cross section having at least two arms a, or a shape capable of obtaining such a fiber cross section. be done. . In the case of cupra fiber bundles, the temperature of the hot water injected into the coagulating liquid injector is raised to promote coagulation, and the Jet Draft ratio is increased to make the fiber cross-sectional shape more consistent with the shape of the nozzle hole of the spinneret. This makes it easier to control the cross-sectional shape of the fiber.

(Example 1)
As the raw material viscose, viscose containing 8.5% by mass of cellulose, 5.7% by mass of sodium hydroxide, 2.7% by mass of carbon disulfide, and the balance being water was used. 2.6% by mass of a black pigment (carbon black) was added. A Mueller bath (60° C.) containing 145 g/liter of sulfuric acid, 15 g/liter of zinc sulfate and 350 g/liter of sodium sulfate was used as a spinning bath. A spinneret for discharging viscose was provided with 126 spinneret holes having a hole diameter of 0.35 mm.

When the yarn was taken off by the take-off roller, the angle θ (see FIG. 3) formed between the line connecting the center of the spinneret and the take-off roller and the bath surface of the spinning bath was 90°. In addition, the length L ₁ of the segment within the spinning bath (see FIG. 3) and the length L ₂ of the segment from the intersection of the line segment and the bath surface of the spinning bath to the take-up roller (see FIG. 3) ) were set to 500 mm and 200 mm, respectively. Other spinning conditions were set as shown in Table 1 to produce the viscose rayon fiber bundle of Example 1.

(Example 2)
The spinneret used in Example 1 was provided with 1,000 spinneret holes having a hole diameter of 0.18 mm, and the spinning conditions shown in Table 1 were used as the spinneret for discharging viscose. A viscose rayon fiber bundle of Example 2 was produced in the same manner as in Example 1 (θ, L ₁ and L ₂ are the same as those in Example 1) using viscose and a spinning bath.

(Comparative example 1)
Comparison was performed in the same manner as in Example 1 using the viscose and spinning bath used in Example ₁ , except that L1 and L2 _were 230 mm and 150 mm, respectively, and the spinning conditions were as shown in Table 1. A viscose rayon fiber bundle of Example 1 was produced.

(Comparative example 2)
Using the viscose and spinning bath used in Example 1, spinning was carried out under the following spinning conditions.
When the yarn was taken off by the take-off roller, the angle θ formed by the line connecting the center of the spinneret and the take-off roller and the bath surface of the spinning bath was 15.3°. Also, the length L1 of the portion of the line segment in the spinning bath, and the length L2 of the portion from the intersection of the line segment and the bath surface of the spinning bath to the take-up roller were 513 mm and 549 mm, respectively. Other spinning conditions were set as shown in Table 1, and a viscose rayon fiber bundle of Comparative Example 2 was produced.

The cross sections of the obtained viscose rayon fiber bundles of Example 1 and Comparative Example 1 were observed with an optical microscope. FIG. 1(a) shows a cross-sectional photograph of the fiber bundle of Example 1, and FIG. 1(b) shows a cross-sectional photograph of the fiber bundle of Comparative Example 1. As shown in FIG. 1(a), in the fiber bundle of Example 1, a viscose rayon fiber having an irregular cross section and a constriction formed by a plurality of arm portions was produced. I was able to confirm that As shown in FIG. 1(b), arms and constrictions were observed in the fiber bundle of Comparative Example 1 as well, but the lengths of the arms were relatively short, and the length/width ratio was as described below. was less than 1.5.

30 fibers are arbitrarily extracted from the fiber bundles of each example and each comparative example, and each fiber has an arm portion whose length/width ratio is within the numerical range shown in Table 2 in the cross section of each fiber Viscose rayon The ratio (%) of fibers was determined. In the case of having a plurality of arms and having arms belonging to two or more of the length/width ratio divisions shown in Table 2, the arm having the largest length/width ratio was used as a reference. . In addition, the ratio of the specific viscose rayon fibers obtained by this method can be regarded as the volume % of the specific viscose rayon fibers, since all the fibers constituting the fiber bundle have substantially the same fineness.

Furthermore, in the fiber bundles of each example and each comparative example, fibers having arms a having a length/width ratio of 1.5 or more and less than 2.5 were extracted. The ratio (%) of the viscose rayon fiber that gives the value was determined. Furthermore, among the viscose rayon fibers A (fibers having at least two arms a), the proportion of fibers containing one arm a having a medium thickness and fibers containing two or more arms a, and the arm a having a bent shape The ratio of fibers containing one and fibers containing two or more was determined. Table 2 shows the results.
Among the 30 fibers extracted from the fiber bundles of Examples 1 and 2, the width and length of all the arms a of the viscose rayon A were obtained, and the average value was calculated. , the average width was 23.6 μm and the average length was 40.0 μm, and the average width was 16.6 m and the average length was 28.1 μm for Example 2. . The width of the arm portion a of the fiber cross section of the viscose rayon A contained in the fiber bundles of Examples 1 and 2 was 14.8 μm to 33.1 μm (Example) and 10.8 μm to 23.8 μm (Example 2) was within the range. Further, in Comparative Example 2, the average width of the arms having a length/width ratio of 2.5 or more was 19.1 μm.

Furthermore, the fiber bundles of Examples and Comparative Examples were measured for single fiber fineness, dry strength, wet strength, dry elongation, and wet elongation based on JIS L 1015. Table 3 shows the results.

As shown in Table 2, in Examples 1 and 2, many viscose rayon fibers having arms with a length/width ratio of 1.5 or more and less than 2.5 were formed, and such arms In Example 1, the ratio of fibers having two or more was 84% by volume, and in Example 2, it was 60% by volume. In the fiber bundle of Comparative Example 1, the arm length/width ratio was less than 1.5 at 67% by volume of fibers, which is believed to be due to the higher Jet Draft ratio in Comparative Example 1. In Comparative Example 2, most of the viscose rayon fibers had arms with a length/width ratio of 2.5 or more. This is because the fiber bundle was drawn so that the spun yarn was slanted with respect to the bath surface of the spinning bath, so that the surface layer formation and dehydration shrinkage during coagulation and regeneration differed from those of the examples. Conceivable.

For the fiber bundles of Examples 1 and 2, and Comparative Examples 1 and 2, the bulk/convergence/dividability of the fiber bundle, the rigidity of the fiber bundle, and the liquid retention of the fiber bundle were evaluated according to the following evaluation criteria. was evaluated according to Table 4 shows the results. Three examples were compared relative to each other in terms of rigidity.

(Bulk/Convergence/Separation)
S Bulky and easy to bundle and separate A Bulky and easy to bundle but difficult to separate B Low bulk

(Rigidity)
S: Moderately rigid and flexible A: The most rigid B: The least rigid

(liquid retention)
S Easy to hold liquid B Hard to hold liquid

The present disclosure includes the following aspects.
(Aspect 1)
A regenerated cellulose fiber,
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width does not have an arm that is 2.5 times or more of
regenerated cellulose fibres.
(Aspect 2)
The regenerated cellulose fiber according to aspect 1, wherein the arm portion a has a width of 5 μm or more and 50 μm or less.
(Aspect 3)
3. The regenerated cellulose fiber according to aspect 1 or 2, wherein the fiber cross section has two or three arms a.
(Aspect 4)
The regenerated cellulose fiber according to any one of aspects 1 to 3, wherein at least two of the arm portions a have a medium thick shape.
(Aspect 5)
The regenerated cellulose fiber according to any one of aspects 1 to 4, wherein at least one of the arm portions a has a bent shape.
(Aspect 6)
The regenerated cellulose fiber according to any one of aspects 1 to 5, wherein the fiber cross section includes an arm portion b having a length of 1 to 1.5 times the width as an arm portion other than the arm portion a.
(Aspect 7)
The regenerated cellulose fiber according to any one of aspects 1 to 6, wherein the regenerated cellulose fiber is a viscose rayon fiber obtained by coagulating and regenerating viscose.
(Aspect 8)
The regenerated cellulose fiber according to any one of aspects 1 to 7, wherein the regenerated cellulose fiber has an irregular fiber cross section.
(Aspect 9)
A regenerated cellulose fiber assembly containing 35% by volume or more of the regenerated cellulose fiber according to any one of aspects 1 to 8.
(Mode 10)
The regenerated cellulose fiber according to aspect 9, wherein the regenerated cellulose fiber aggregate is a regenerated cellulose fiber bundle formed by bundling a plurality of regenerated cellulose fibers or an aggregate of short fibers formed by cutting the regenerated cellulose fiber bundle into a predetermined length. Aggregation.
(Aspect 11)
The average width and average length of the arm portions a of the regenerated cellulose fibers A contained in the 30 regenerated cellulose fibers arbitrarily selected from the regenerated cellulose fiber aggregate satisfy at least one of the following: The regenerated cellulose fiber assembly according to claim 9.
(i) The average width of the arm portions a of the regenerated cellulose fibers A is 5 μm or more and 50 μm or less.
(ii) The average length of the arms a of the regenerated cellulose fibers A is 20 m or more and 60 μm or less.
(Aspect 12)
A fiber assembly containing 20% by volume or more of the regenerated cellulose fiber assembly according to any one of aspects 9 to 11.
(Aspect 13)
A fiber bundle is formed by discharging viscose into the spinning bath from a plurality of spinneret holes provided in a spinneret, and solidifying and regenerating the viscose, and the fiber bundle is provided outside the spinning bath. A method for producing a viscose rayon fiber bundle comprising a plurality of bundles of viscose rayon fibers, comprising taking up with a take-up roller,
The mouthpiece hole has a hole diameter of 0.15 mm or more and 0.5 mm or less,
V2/V1 is 0.5 to 1.5, where V1 is the discharge speed of the viscose at the exit of the spinneret hole, and V2 is the take-up speed of the fiber bundle by the take-up roller,
When the fiber bundle is taken up by the take-up roller, the take-up direction of the spun yarn positioned substantially at the center of the fiber bundle in the spinning bath forms an angle of 80° or more and 110° with the bath surface of the spinning bath. Carry out the pick-up so that:
A method for producing a viscose rayon fiber bundle, comprising obtaining a fiber bundle containing viscose rayon fibers having a single fiber fineness of 20 dtex or more and 160 dtex or less.
(Aspect 14)
A viscose rayon according to aspect 13, wherein the viscose rayon is taken up so that the length of the spun yarn positioned substantially at the center of the fiber bundle is 400 mm or more between the spinneret and the bath surface of the spinning bath. A method for producing a fiber bundle.
(Aspect 15)
15. The method for producing a viscose rayon fiber bundle according to

aspect

13 or 14, wherein the take-up speed of the fiber bundle by the take-up roller is 10 m/min or more and 60 m/min or less.
(Aspect 16)
A fiber bundle for artificial hair containing 20% by volume or more of regenerated cellulose fiber bundles in which a plurality of regenerated cellulose fibers are bundled, wherein the regenerated cellulose fiber bundles contain 35% by volume or more of regenerated cellulose fibers A having the following configuration. , fiber bundles for artificial hair.
(Structure of regenerated cellulose fiber A)
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
At least two of the arms of the fiber cross section are arms a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width does not have an arm that is 2.5 times or more of
(Aspect 17)
17. The fiber bundle for artificial hair according to aspect 16, wherein the regenerated cellulose fibers are viscose rayon fibers obtained by coagulating and regenerating viscose.
(Aspect 18)
Artificial hair comprising the fiber bundle for artificial hair according to

aspect

16 or 17.
(Aspect 19)
A hair accessory using the artificial hair of aspect 18.

The regenerated cellulose fiber of the present disclosure has bulkiness and rigidity that have not been obtained with conventional regenerated cellulose fibers, and is used as artificial hair for hair accessories or as a resin kneading material for patterning plastic molded products. , blasting materials for deburring circuit boards, filters, civil engineering materials that require biodegradability (nets, cheesecloth, sandbags, curing mats), spun yarns used for crisp clothing, cleaning tools It can be used for mops, sponges for bathing, and the like.

A Viscose Rayon A
10, 11

Constriction

12, 13, 14 Arm a
30 spinning bath 30a bath surface 31 spinneret 32 fiber bundle 32a yarn spun from a spinneret hole provided substantially in the center of the spinneret 33 take-up roller

Claims

A regenerated cellulose fiber,
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width does not have an arm that is 2.5 times or more of
regenerated cellulose fibres.
The regenerated cellulose fiber according to claim 1, wherein the arm portion a has a width of 5 μm or more and 50 μm or less.
The regenerated cellulose fiber according to claim 1 or 2, wherein the fiber cross section has two or three arms a.
The regenerated cellulose fiber according to any one of claims 1 to 3, wherein at least two of the arm portions a have a medium thick shape.
The regenerated cellulose fiber according to any one of claims 1 to 4, wherein at least one of the arms a has a bent shape.
The regenerated cellulose according to any one of claims 1 to 5, wherein the fiber cross section includes an arm b whose length is 1 time or more and less than 1.5 times the width as an arm other than the arm a. fiber.
The regenerated cellulose fiber according to any one of claims 1 to 6, wherein the regenerated cellulose fiber is a viscose rayon fiber obtained by coagulating and regenerating viscose.
The regenerated cellulose fiber according to any one of claims 1 to 7, wherein the regenerated cellulose fiber has an irregular fiber cross section.
A regenerated cellulose fiber assembly containing 35% by volume or more of the regenerated cellulose fiber according to any one of claims 1 to 8.
10. The regenerated cellulose fiber aggregate according to claim 9, wherein the regenerated cellulose fiber bundle is a regenerated cellulose fiber bundle formed by bundling a plurality of regenerated cellulose fibers or a short fiber aggregate formed by cutting the regenerated cellulose fiber bundle into a predetermined length. Regenerated cellulose fiber aggregate.
The average width and average length of the arm portions a of the regenerated cellulose fibers A contained in the 30 regenerated cellulose fibers arbitrarily selected from the regenerated cellulose fiber aggregate satisfy at least one of the following: The regenerated cellulose fiber assembly according to claim 9.
(i) The average width of the arm portions a of the regenerated cellulose fibers A is 5 μm or more and 50 μm or less.
(ii) The average length of the arms a of the regenerated cellulose fibers A is 20 m or more and 60 μm or less.
A fiber assembly containing 20% by volume or more of the regenerated cellulose fiber assembly according to any one of claims 9 to 11.
A fiber bundle is formed by discharging viscose into the spinning bath from a plurality of spinneret holes provided in a spinneret, and solidifying and regenerating the viscose, and the fiber bundle is provided outside the spinning bath. A method for producing a viscose rayon fiber bundle comprising a plurality of bundles of viscose rayon fibers, comprising taking up with a take-up roller,
The mouthpiece hole has a hole diameter of 0.15 mm or more and 0.5 mm or less,
V2/V1 is 0.5 to 1.5, where V1 is the discharge speed of the viscose at the exit of the spinneret hole, and V2 is the take-up speed of the fiber bundle by the take-up roller,
When the fiber bundle is taken up by the take-up roller, the take-up direction of the spun yarn positioned substantially at the center of the fiber bundle in the spinning bath forms an angle of 80° or more and 110° with the bath surface of the spinning bath. Carry out the pick-up so that:
A method for producing a viscose rayon fiber bundle, comprising obtaining a fiber bundle containing viscose rayon fibers having a single fiber fineness of 20 dtex or more and 160 dtex or less.
14. The method according to claim 13, wherein, between the spinneret and the bath surface of the spinning bath, the take-up is carried out so that the length of the spun yarn positioned substantially at the center of the fiber bundle is 400 mm or more. A method for producing a viscose rayon fiber bundle.
The method for producing a viscose rayon fiber bundle according to claim 13 or 14, wherein the take-up speed of the fiber bundle by the take-up roller is 10 m/min or more and 60 m/min or less.
A fiber bundle for artificial hair containing 20% by volume or more of regenerated cellulose fiber bundles in which a plurality of regenerated cellulose fibers are bundled, wherein the regenerated cellulose fiber bundles contain 35% by volume or more of regenerated cellulose fibers A having the following configuration. , fiber bundles for artificial hair.
(Structure of regenerated cellulose fiber A)
Having a fineness of 20 dtex or more and 160 dtex or less,
The fiber cross section has a plurality of arms and a constriction formed by the arms,
Of the arms of the fiber cross section, at least two arms are arm a whose length is 1.5 times or more and less than 2.5 times the width, and the length of the fiber cross section is the width not have an arm that is 2.5 times or more of
The fiber bundle for artificial hair according to claim 16, wherein the regenerated cellulose fibers are viscose rayon fibers obtained by coagulating and regenerating viscose.
Artificial hair, comprising the fiber bundle for artificial hair according to claim 16 or 17.
A hair accessory using the artificial hair according to claim 18.