JPH08246225A - Modified cross-section hollow fiber and its production - Google Patents

Abstract

PURPOSE: To obtain the subject fiber having excellent separability and opening ability, bulkiness, repulsive elasticity, recoverability, heat retaining property and drapability, etc., and useful for wadding, etc., by making its cross section shape to a specific about pentagon shape having a protrusion part at each apex and a hollow part in the central part. CONSTITUTION: A cross section shape of a synthetic fiber is made to about pentagon shape and a protrusion part is placed at each apex (a ratio of height H to PW: H/W is 0.6-1.0) and a hollow part is arranged in the central part. The maximum side part S1 has 10-30μm radius of curvature and bends to inside of the fiber, and cooling air is blown to the bending point to increase latent crimpability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified cross-section hollow fiber, a method for producing the modified cross-section hollow fiber, a batting and a cushioning material made of the modified cross-section hollow fiber. More specifically, the present invention is excellent in fiber separability, openability, and good bulkiness, impact resilience,
A modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape having excellent properties such as recoverability, heat retention, and drape, which is particularly suitable for applications such as cotton stuffing and cushioning materials, and a method for producing the same. The present invention relates to a batting and a cushioning material made of the hollow fiber having a modified cross section.

[0002]

2. Description of the Related Art In the field of application such as cushioning materials for cushions, pillows, dolls, stuffed cotton for quilts, etc., feathers of birds have been widely used, but natural feathers are limited in quantity and quality. The use amount thereof tends to decrease due to reasons such as unevenness and high price, and staple fibers made of synthetic fibers have been widely used instead of natural feathers. However, since staple fibers of ordinary synthetic fibers are inferior in properties such as bulkiness, impact resilience, and recoverability, in order to improve those properties, the synthetic fibers having a circular cross-sectional shape are spun from one direction during spinning. Rapid cooling, or composite spinning of multiple polymers with different viscosities into a side-by-side type to impart latent crimpability to the fiber and then develop a three-dimensional crimp, and a processing agent such as silicone resin on the fiber surface. The method of applying is widely adopted.

However, for example, in the case where a synthetic fiber having a circular cross section is melt-spun by a conventional method by quenching from one direction,
If the three-dimensional crimping performance is increased in order to improve the bulkiness, impact resilience, and recoverability of the fiber, the separability and opening property of the fiber are deteriorated, and the formation of aggregates (agglomeration) easily occurs.
It is difficult to perform filling work into the foreskin such as bedding and into the mold, and conversely, the properties such as bulkiness, impact resilience, recovery, heat retention, and drape are deteriorated. Also, in the case of a method of applying a processing agent such as a silicone resin on the surface of the fiber, the adhesive force of the processing agent remains even after the fiber is dried, which causes adhesion between the single fibers, and the separation property of the fiber There are drawbacks such as poor openability and reduced bulkiness, impact resilience, recoverability, heat retention, drapeability, and the like.

[0004]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is that the fiber has good separability and openability, and is excellent in various properties such as bulkiness, impact resilience, recovery, heat retention, and drape. The purpose of the present invention is to provide a synthetic fiber, particularly a synthetic fiber suitable as a stuffed cotton or a cushion material. And an object of the present invention is to provide a method capable of smoothly and reliably producing synthetic fibers having such excellent properties. Furthermore, it is an object of the present invention to provide battings and cushions made of synthetic fibers having such excellent properties.

[0005]

As a result of repeated studies by the present inventors in order to achieve the above object, the cross-sectional shape of a synthetic fiber has a protrusion at each apex and a central portion at its center. When a specific substantially pentagonal shape with a hollow part is formed, a synthetic fiber is obtained that has good fiber separability and openability, as well as various properties such as bulkiness, impact resilience, recovery, heat retention, and drape. It has been found that the modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape is particularly suitable as a stuffed cotton or cushioning material. Furthermore, the present inventors have found that a modified cross-section hollow fiber having a specific substantially pentagonal cross-sectional shape having such excellent properties has a C-shape having protruding slits of specific dimensions on its outer and inner sides. It was found that the fiber-forming thermoplastic polymer can be obtained by melt spinning from a spinning nozzle composed of slits, and the present invention was completed based on these findings.

That is, the present invention is a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape, the cross-sectional shape of which is the following requirements (i) to (iii); It is composed of a side part (S ₁ ) and four side parts (S ₂ , S ₃ , S ₄ , S ₅ ) shorter than the side part, and the side part in order from one end of the largest side part (S ₁ ). Part (S ₂ ), side part (S ₃ ), side part (S ₄ ) and side part (S ₅ ) are connected to the other end of the largest side part (S ₁ ) to form a hollow substantially pentagonal shape. (Ii) the maximum side portion (S ₁ ) is curved toward the inside of the fiber with a radius of curvature of 10 to 30 μm; and (iii) the five substantially pentagonal shapes. Each of the apexes has a protrusion having a ratio (H / W) of height (H) to width (W) of 0.6 to 1.0; Is a modified cross-section hollow fibers having a cross-sectional shape of substantially pentagonal, characterized.

The present invention is a method for producing a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape by melt-spinning a fiber-forming thermoplastic polymer, which comprises the following requirements provided in a spinneret: A spinning nozzle comprising: a C-shaped slit, and two parallel slits (A ₁ , A ₁ ) are connected to the C-shaped slit inwardly with a connecting portion between both ends of the C-shaped slit sandwiched therebetween. And 5 to 9 linear slits (B ₁ ) are connected to the C-shaped slit with the connecting portion of the C-shaped slit being sandwiched between the linear slits (B ₁ ) facing outward. Two straight slits (B) symmetrically provided near the connecting portion with the connecting portion of the C-shaped slit interposed therebetween.
_The angle (θ ₁ ) formed by ₁ , B ₁ ) is 100 ° to 130 °;
When the area of the slit (A ₁ ) is a and the area of the linear slit (B ₁ ) is b, a / b is 0.3 to 0.6; A method for producing a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape, which comprises discharging a hydrophilic thermoplastic polymer and spinning the polymer.

Further, the present invention includes a cotton stuffing comprising a modified cross-section hollow fiber having the above-mentioned substantially pentagonal cross-sectional shape and a cushioning material using the modified cross-section hollow fiber.

Although not limited thereto, the present invention will be described in detail with reference to the drawings. A modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape according to the present invention is shown in FIG.
As illustrated in (e), a substantially pentagonal cross section composed of one maximum side portion (S ₁ ) and four shorter side portions (S ₂ , S ₃ , S ₄ , S ₅ ). It has a shape, and the side portion (S ₂ ) and the side portion (S ₂ ) are sequentially arranged from one end of the maximum side portion (S ₁ ).
₃ ), the side portion (S ₄ ) and the side portion (S ₅ ) are connected to the other end portion of the maximum side portion (S ₁ ) to form a hollow pentagon [the above requirement (i )] And the largest side (S ₁ ) is curved toward the inside of the fiber with a radius of curvature (r) of 10 to 30 μm [above requirement (ii)].

That is, in the modified cross-section hollow fiber of the present invention, the side portion (S ₁ ) curved toward the inside of the fiber with the radius of curvature (r) of 10 to 30 μm is the side portion (S ₁ ) to the side. It is necessary to have the maximum length of the part (S ₅ ) so that when cooling air is blown from the side (S ₁ ) direction during the production of the modified cross-section hollow fiber of the present invention. In addition, the cooling air efficiently hits the maximum inwardly curved side portion (S ₁ ) and the cooling air is less likely to be blown directly to the other side portions, so that the maximum side portion (S ₁ ) and other Side (S ₂ )
~ A large difference in internal structure (for example, difference in crystal structure, orientation structure, etc.) occurs between the side portion (S ₅ ) and, as a result, a high potential crimping ability can be imparted to the modified cross-section hollow fiber.

Further, in the modified cross-section hollow fiber of the present invention, as shown in FIG. 2 as a representative, a tangent line is drawn at the bottom of each side part, and the side part (S ₁ ) length s ₁ , side (S ₂ ) length s ₂ , side (S ₃ ) length s
₃ , the side portion (S ₄ ) length s ₄ and the side portion (S ₅ ) length s ₅
When each is calculated, the maximum side length (S ₁ ) of the length s ₁
Is about 1.3 to 2.3 times the lengths s ₂ , s ₃ , s ₄ , and s ₅ of the remaining four side portions (S ₂ ) to side portions (S ₅ ). It is desirable that the bulkiness, impact resilience, and recoverability of the modified cross-section hollow fiber can be improved.

Further, in the modified cross-section hollow fiber of the present invention,
Sides (S ₂₎ the length s ₂ and the side portion of (S ₅₎ substantially similar to to and side portion of the length s ₅ of (S ₃₎ of length s ₃ and the side portion length of (S ₄₎ It is desirable that the length s ₄ is substantially the same, and by doing so, the cross-sectional shape of the modified cross-section hollow fiber forms a straight line XX that passes through the center of the side portion (S ₁ ) substantially vertically. It becomes line-symmetrical (right and left symmetrical in Fig. 1 and Fig. 2) by sandwiching it, and the shape and internal structure of the hollow fiber with a modified cross section becomes more balanced, so that impact resilience, recovery, and settling resistance etc. Will be even better. In that case, the side (S
₂ ) and the side portion (S ₅ ) have a cross-sectional shape that is substantially perpendicular to the side portion (S ₁ ), the impact resilience,
It is more desirable because it is possible to obtain a hollow fiber with a modified cross section that is more excellent in recoverability and settling resistance.

Further, in the modified cross-section hollow fiber of the present invention, the radius of curvature (r) of the maximum side portion (S ₁ ) curved inward is
It is necessary that the thickness is in the range of 10 to 30 μm, and the radius of curvature (r) is preferably 15 to 25 μm. If the radius of curvature (r) of the side portion (S ₁ ) is less than 10 μm, the ratio of hollow portions in the modified cross-section hollow fiber, that is, the hollow ratio becomes small, resulting in insufficient bulkiness and heat retention, which results in a wadding. And lack of suitability as a cushion material. On the other hand, the radius of curvature (r) of the side portion (S ₁ ) is 3
When it exceeds 0 μm, when the modified cross-section hollow fiber is manufactured, particularly when the discharged fiber for imparting the latent crimping ability is cooled by blowing cooling air from the direction of the maximum side portion (S ₁ ) thereof, Crushing frequently occurs, the hollow ratio decreases, bulkiness,
The heat retention and drape properties deteriorate, making it unsuitable for applications such as stuffed cotton and cushioning materials.

Further, the modified cross-section hollow fiber of the present invention has a substantially pentagonal shape with the above-mentioned requirements (i) and (ii).
The ratio of height (H) to width (W) (H /
W) is 0.6 to 1.0 and the protrusions (E ₁ , E ₂ , E ₃ ,
E _4, E ₅₎ it is necessary to a have respectively. Here, the protrusions (E ₁ , E ₂ , E ₃ , E ₄ ,
E ₅₎ the width (W) of, as shown in FIG. 2, the two lowest valley portions on both sides of the protrusions _{(E 1, E 2, E} 3, E 4, E 5) (d, e ) indicates the length of a straight line connecting, also projections _{(E 1, E 2, E} 3, E 4, E 5) of the height (H) and the respective projecting portions _{(E 1, E 2, E} 3, The length of a perpendicular line drawn from a peak point (f) of E ₄ , E ₅ ) to a straight line connecting the two valleys (d, e).

The ratio (H / W) of the height (H) to the width (W) of the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) is less than 0.6, or substantially zero. If there are no protrusions at each vertex of the pentagon, the separability and openability of the fibers will be insufficient, and the bulkiness, impact resilience, recoverability, heat retention, drapeability, etc. will be poor. On the other hand, if the ratio (H / W) of the height (H) to the width (W) of the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) exceeds 1.0, the modified cross-section hollow fiber When melt-spinning is performed by blowing cooling air from the direction of the maximum side portion (S ₁ ) of the fiber, the fiber does not become hollow but becomes a so-called punctured state (hollow cracking state), and the processability during spinning is improved. It becomes defective, and the properties such as bulkiness, impact resilience, recoverability, and heat retention are deteriorated. Excellent separability and openability, bulkiness, impact resilience,
In order to obtain a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape that is excellent in various properties such as recovery, heat retention, and drapeability, with good processability, the protrusions at the five vertices of the modified cross-section hollow fiber ( The ratio (H / W) of the height (H) to the width (W) of E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) is 0.7 to 0.
The range of 8 is more preferable.

The shape and size of the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) present at the five vertices of the substantially pentagon [especially the width (W) and / or the height (H)] May be the same or different, but are preferably about the same shape and size. In particular, the protrusions (E ₁ ) and (E ₅ ) which are line-symmetrical with respect to the straight line XX passing through the center of the side portion (S ₁ ) have substantially the same shape and size, and The portion (E ₂ ) and the protrusion (E ₄ ) have substantially the same shape and size, which is a variant having well-balanced and good bulkiness, impact resilience, recovery, and drapeability. It is desirable in that a hollow fiber in cross section can be obtained. In addition, although not limited thereto, each protrusion (E ₁ , E ₂ ,
The height (H) of E ₃ , E ₄ , E ₅ ) is about ⅕ to ⅛ of the maximum diameter (the maximum diameter including the protrusions) of the modified cross-section hollow fiber.
It is desirable to set the degree to an extent in order to obtain a modified cross-section hollow fiber having excellent properties such as separability, fiber-opening property, bulkiness, impact resilience, recovery property, heat retention property, and drape property.

In addition, in the modified cross-section hollow fiber having the substantially pentagonal cross-sectional shape of the present invention, the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) are provided at the above-mentioned five apexes, and For example, as illustrated in (c) to (e) of FIG. 1, one or two of the side portions (S ₂ ) to the side portion (S ₅ ) may be provided with one or two as needed. You may further provide a protrusion part. In that case, the width and height of the protrusions provided on the side portion (S ₂ ) to the side portion (S ₅ ) are the same as those of the protrusions (E ₁ , E ₂ ,
The width (W) and the height (H) of E ₃ , E ₄ , E ₅ ) are set to the following values in order to improve the separability, openability, and bulkiness of the modified cross-section hollow fiber. desirable. Further, the total number of protrusions at each apex of each modified cross-section hollow fiber or each vertex and each side (S ₂ ) to side (S ₅ ) is 5 to 9, that is, the modified cross-section hollow fiber. It is desirable from the viewpoint of maintaining good separability, openability, impact resilience, recoverability, heat retention, and drape.

The thickness (single fiber fineness) of the modified cross-section hollow fiber of the present invention can be appropriately adjusted according to the application and the like, but generally, it is preferably about 3 to 60 denier. Further, the hollowness of the modified cross-section hollow fiber of the present invention (area ratio of the hollow portion obtained from the cross-sectional area of the fiber) is usually
About 8 to 40% is the bulkiness, impact resilience,
It is preferable in terms of recoverability, heat retention, drapeability and the like.

The fiber-forming thermoplastic polymer constituting the modified cross-section hollow fiber of the present invention may be any thermoplastic polymer capable of forming fibers by melt spinning, and examples thereof include polyester-based polymers and polyolefin-based polymers. Polymer,
Polyamide polymer, polyvinyl alcohol polymer,
Examples thereof include polyurethane polymers. Among them, fiber-forming polyester-based polymers and polyolefin-based polymers are preferable, and fiber-forming polyester-based polymers are more preferable.

When the fiber-forming polyester polymer is used, terephthalic acid or its ester-forming derivative is used as the main dicarboxylic acid component, and ethylene glycol and / or 1,4-butanediol is reacted as the main diol component. The polyethylene terephthalate-based polymer and / or polybutylene terephthalate-based polymer thus obtained is more preferably used. And
When a polyethylene terephthalate polymer and / or a polybutylene terephthalate polymer is used,
It is possible to obtain a modified cross-section hollow fiber which is excellent in various properties such as separability, openability, impact resilience, recovery, heat retention, and drape, and which is extremely suitable as a stuffed cotton and a cushioning material.

At this time, the polyethylene terephthalate polymer and / or the polybutylene terephthalate polymer may be added in a small amount (usually 30 mol% or less) of other dicarboxylic acid component, oxycarboxylic acid component, other You may have 1 type (s) or 2 or more types of a diol component and a polyol component as a copolymerization unit. In that case, other dicarboxylic acid components include, for example, aromatic dicarboxylic acids such as isophthalic acid, diphenyldicarboxylic acid and naphthalenedicarboxylic acid, or ester-forming derivatives thereof;
-Dimethyl sodium sulfoisophthalate, Bis (2-hydroxyethyl) 5-sodium sulfoisophthalate
Examples thereof include metal sulfonate group-containing aromatic carboxylic acid derivatives; aliphatic dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid, and dodecanedioic acid, or ester-forming derivatives thereof. In addition, examples of the oxycarboxylic acid component include p-oxybenzoic acid, p-β-oxyethoxybenzoic acid, and their ester-forming derivatives. Examples of other diol components include aliphatic diols such as 1,3-propanediol, 1,6-hexanediol, neopentyl glycol; 1,4-bis (β-oxyethoxy) benzene, polyethylene glycol, poly Butyl glycol and the like can be mentioned. Further, it may be modified with a polyol component such as pentaerythritol.

When a polyolefin-based polymer is used as the fiber-forming thermoplastic polymer, for example, polypropylene or polyethylene is used, and when a polyamide-based polymer is used, 6-nylon, 6,6-nylon, 6, 1
Examples thereof include 0-nylon, 7-nylon, 9-nylon and 11-nylon.

Further, the modified cross-section hollow fiber may be composed of one kind of fiber-forming thermoplastic polymer, or may be a blend of two or more kinds of fiber-forming thermoplastic polymer. Further, the fiber-forming thermoplastic polymer, if necessary, conventionally used in the production of fibers, inorganic fine particles, aromatics, antibacterial agents, flame retardants, deodorants, pigments, matting agents, heat You may contain 1 type, or 2 or more types of additives, such as a stabilizer, a light stabilizer, and an antistatic agent. Further, the modified cross-section hollow fiber of the present invention, if necessary, various treatments such as a drape property of a silicone resin and a feather touch imparting agent, an antibacterial agent, an insect repellent, a fungicide, a flame retardant, a deodorant, etc. The surface treatment or processing treatment may be performed with an agent.

The modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape according to the present invention has various properties such as good bulkiness, impact resilience, recoverability, heat retention, and drapeability by itself. It can be effectively used as a fiber for cotton, cushioning material and cloth. However, when the modified cross-section hollow fiber of the present invention is used as a padded cotton or cushioning material,
The fibers discharged from the spinning nozzle at the time of spinning the modified cross-section hollow fiber are unidirectionally blown with cooling air from the direction of the maximum side portion (S ₁ ), and the side portion (S ₁ ) and the other side When a difference in internal structure (for example, crystal structure, orientation structure, etc.) between the part (S ₂ ) and the side part (S ₅ ) is caused, a high latent crimping ability is imparted to the fiber and the crimping is expressed. The fibers have extremely high bulkiness, impact resilience, recoverability, and heat retaining property, and are more suitable for applications as padded cotton and cushioning materials.

The modified cross-section hollow fiber of the present invention can be used in the form of filament fiber or can be cut into staples, and when it is used as a stuffed cotton or a cushioning material, it is usually about 20 to 60 mm. After cutting into staples, before or after cutting into staples, or after being filled in the skin or mold of a futon or cushion,
It may be used after being subjected to heat treatment or the like to develop crimps.

In the case of a hollow fiber having a circular or elliptical cross-sectional shape, when the cooling air is blown from one side to the fiber discharged from the spinning nozzle in order to impart the latent crimping ability to the fiber, the hollow part is formed. Crushing, separability, openability, bulkiness,
Although the impact resilience, recoverability, heat retention, drapeability, etc. are reduced, the modified cross-section hollow fiber of the present invention has the above-mentioned (i) to
By having a specific substantially pentagonal cross-sectional shape satisfying the requirement of (iii), cooling from the direction of the maximum side portion (S ₁ ) of the fiber in order to impart high latent crimping ability to the fiber Even if the fiber is spun while blowing air, the hollow part does not collapse, disappears, or breaks, and is separable, openable, and bulky.
Fibers having excellent properties such as impact resilience, recoverability and heat retention can be smoothly obtained. And, in general, the modified cross-section hollow fiber having the substantially pentagonal cross-sectional shape of the present invention having the above-described requirements is 95.0 after being opened by a turbo opener-type opening machine by the method described in the Examples section below. Has a high open rate of more than 100% and its specific volume is 105 cm ³ /
It is g or more, and has good openability and high bulkiness.

The method for producing the modified cross-section hollow fiber of the present invention is not particularly limited, as long as it is a method capable of producing a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape satisfying the above-mentioned requirements (i) to (iii). Either is fine. In particular, since the modified cross-section hollow fiber of the present invention can be smoothly produced by discharging the melted fiber-forming thermoplastic polymer from the spinneret provided with a spinning nozzle having the following requirements to perform spinning: The present invention includes such a spinning method (fiber manufacturing method) within the scope of the present invention.

Therefore, the manufacturing method of the present invention will be described with reference to the drawings. In the method of the present invention, as a spinning nozzle, as illustrated in FIGS. 3 (a) to 3 (c), a C having a connecting portion (D) which is not cut out in a slit shape in a part of an annular slit. Two parallel slits having a V-shaped slit (C) and facing inward with a connecting portion (D) between the both ends of the C-shaped slit interposed therebetween.
(A ₁ , A ₁ ) are continuously connected to the C-shaped slit (C); 5 to 9 linear slits (B) sandwiching the connecting portion (D) with respect to the C-shaped slit (C). ₁ ) are continuously provided toward the outside; two linear shapes symmetrically provided near the connecting portion (D) with the connecting portion (D) of the C-shaped slit (C) interposed therebetween. slits (B _1, B ₁₎ an angle of (theta ₁₎ is 100
And the area of the slit (A ₁ ) is a and the area of the linear slit (B ₁ ) is b, a / b is 0.3 to 0.6. The requirement of the present invention is that the melted fiber-forming thermoplastic polymer is discharged from a spinneret provided with a spinneret having the requirement to satisfy the requirement to spin the fiber-forming thermoplastic polymer. A hollow fiber having a modified cross section can be smoothly produced.

Here, two linear slits (B ₁ ,
The angle (θ ₁ ) formed by B ₁ ) means the center of each width (Bw) of the two linear slits (B ₁ , B ₁ ) and the C-shaped slit (C) as shown in FIG. The angle formed by two straight lines passing through the center of Furthermore, a slit (area of a portion indicated by oblique lines in FIG. 3) the area of the portion of the slit to the area a which projects from the inner periphery of the C-shaped slits (C) inwardly (A ₁₎ of (A _1), also refers to the area of the portion of the linear slit slit projecting outwardly from the outer periphery of (B ₁₎ C-shaped slits and the area b of (C) (B ₁₎ (the area of the portion indicated by hatching in FIG. 3) .

More specifically, when melt spinning is performed from a spinneret having a spinning nozzle of FIG. 3A, protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) are formed at five apexes of a substantially pentagon. 1 (a) having a modified cross-section hollow fiber is formed, and when melt spinning is performed from a spinneret having a spinning nozzle of FIG. 3 (b), protrusions (E ₁ , E ₂ ) are formed at five apexes of a substantially pentagon. , E ₃ ,
E _4, E ₅₎ the modified cross-section hollow fibers of FIG. 1 (b) having a is formed, also projections to five vertexes of substantially pentagonal when melt spun from a spinneret having a spinning nozzle of Fig. 3 (c) The modified cross-section hollow fiber of FIG. 1 (c) having (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) and protrusions on the sides (S ₂ ) and sides (S ₅ ) is also used. It is formed.

When melt-spinning a fiber-forming thermoplastic polymer from a spinning nozzle as exemplified in FIGS. 3A to 3C, the spinning nozzle in the spinneret has a C-shaped slit (C). Spinning nozzle (5) which is not connected to the outside with 5 to 9 linear slits (B ₁ ) sandwiching the connecting portion (D) (spinning nozzle not satisfying the above requirements)
In such a case, it becomes impossible to obtain a modified cross-section hollow fiber having a pentagonal cross-sectional shape and having protrusions at its five vertices. In addition, two linear slits (B ₁ , B ₁ ), which are symmetrically provided near the connecting portion (D) with the connecting portion (D) interposed therebetween.
The angle (θ ₁ ) formed by B ₁ ) deviates from the above requirement and is 10
If it is less than 0 °, the side portion (S ₁ ) does not become the maximum side portion,
On the other hand, when the angle is larger than 130 °, the fibers are flat and the hollow portion cannot be formed smoothly.

Further, the area a of the slit (A ₁ ) provided inward with the connecting portion (D) between the both ends of the C-shaped slit (C) and the outside of the C-shaped slit (C) provided. The ratio of the area of the linear slit (B ₁ ) to the area b (a /
b) is less than 0.3 out of the above requirements,
The radius of curvature (r) of the maximum inwardly curved side portion (S ₁ ) in the hollow fiber of irregular cross section is 10 to 30 μm as described above.
When the modified cross-section hollow fiber is manufactured, the cooling air is blown from the maximum side (S ₁ ) direction in order to give the fiber a high potential crimping capacity. In such a case, the fibers are often crushed and the hollow ratio is reduced, resulting in a decrease in bulkiness, impact resilience, recoverability, heat retention, etc., which makes them unsuitable for applications such as cotton wool and cushioning materials.
On the other hand, if the above ratio (a / b) is larger than 0.6, the maximum inwardly curved side portion (S
_The radius of curvature (r) of ₁ ) becomes less than 10 μm, the hollow ratio in the modified cross-section hollow fiber becomes small, and the properties such as bulkiness, impact resilience, recoverability, and heat retention become inferior. It lacks in suitability as a stuffed cotton or cushioning material.

Further, in order to make the radius of curvature (r) of the maximum side portion (S ₁ ) 10 to 30 μm, the slit
The ratio (a / b) of the area a of (A ₁ ) to the area b of the linear slit (B ₁ ) is set to 0.3 to 0.6, and the slit
(A ₁₎ The length of the (Ah) to approximately 0.45 to 0.75 of C-shaped inner diameter of the slit (C), the width of the slit (A ₁₎ (A
w) is about 0.37 of the height (Ah) of the slit (A ₁ ).
It is preferably 0.45.

Further, when melt-spinning the fiber-forming thermoplastic polymer from the spinning nozzle as exemplified in FIGS. 3 (a) to 3 (c), the protrusions (E ₁ , In order to make the ratio (H / W) of the height (H) to the width (W) of E ₂ , E ₃ , E ₄ , E ₅ ) within the above range of 0.6 to 1.0, each straight line -Shaped slit (B ₁ ) width (BW)
To length (Bh) ratio (Bh / BW) is about 2.5-
It is desirable to set it in the range of 4.0, and each linear slit (B ₁ ) with respect to the outer diameter (Cr) of the C-shaped slit (C).
Width (BW) ratio (Bw / Cr) of about 0.11 to 0.20
It is desirable to set it in the range of.

Also, the outer diameter of the C-shaped slit (C) (C
r) and width (Cw) can be adjusted according to the single fiber fineness of the modified cross-section hollow fiber to be produced and the application of the fiber, but usually the outer diameter (Cr) is about 1.0 to 1.8 mm. degree,
And the width (Cw) of about 0.15 to 0.30 mm are preferable in order to obtain a modified cross-section hollow fiber having excellent properties such as bulkiness, impact resilience, recoverability and heat retention. Further, the width (Dw) of the connecting portion (D) of the C-shaped slit (C)
Is preferably about 0.15 to 0.25 mm in order to obtain a hollow fiber having a modified cross section without punctures or hollow cracks.

Further, in order to obtain a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape satisfying the above-mentioned requirements (i) to (iii), the center of the C-shaped slit (C) and the connecting portion. One linear slit (B ₁ ) is provided at a position where the straight line XX passing through the center of (D) intersects with the outer periphery of the C-shaped slit (C) [opposite side of the connecting portion (D) in the C-shaped slit (C)]. ) Is provided and is line-symmetrical with respect to the straight line XX (symmetrically with respect to the straight line XX in FIG. 3),
It is preferable to provide the same number of linear slits (B ₁ ) of 2 to 4 each.

In the spinning nozzle illustrated in FIGS. 3 (a) to 3 (c), the C-shaped slit (C) has a substantially circular shape, but the shape is not limited thereto and may have a slightly different shape. As long as the dimensions of each part of the spinning nozzle satisfy the above requirements (1) to (4), for example, even in the case of a vertically elongated circular shape (elliptical shape) with the connecting portion (D) interposed,
It is possible to obtain a modified cross-section hollow fiber that satisfies the requirements (i) to (iii) described above.

When the fiber-forming thermoplastic polymer is melt-spun from the spinneret having the above-mentioned spinning nozzle to produce the modified cross-section hollow fiber of the present invention, the spinning temperature is selected according to the kind of the polymer used. A usual melt spinning method can be adopted. Although the fibers discharged from the spinneret may be cooled from the entire peripheral surface, as described above, the direction of the connecting portion (D) in the spinning nozzle [the maximum side portion (S ₁ ) of the modified cross-section hollow fiber Direction], the maximum side portion (S ₁ ) of the hollow fiber having a modified cross-section discharged by blowing cooling air
When the cooling is performed mainly from the side, the maximum side portion (S ₁ ) and the other side portions (S ₂ ) to (S ₅ ) have a large internal structure (crystal structure, orientation state, etc.). Due to the difference, it is possible to obtain a hollow fiber having a modified cross section having a higher latent crimping capacity. In that case, the temperature of the cooling air and the blowing speed are
It can be adjusted according to the temperature of the fiber discharged from the die, the spinning take-off speed, the single fiber fineness of the fiber, the type of polymer constituting the fiber, and the like.

For example, polyethylene terephthalate is used as the fiber-forming thermoplastic polymer, and the melting temperature is 270.
In the case of producing a modified cross-section hollow fiber of the present invention having a substantially pentagonal cross-sectional shape of a single fiber fineness of 3 to 60 denier by spinning at a spinning take-up speed of 600 to 1500 m / min at 300 to 300 ° C., a temperature of 20 to 30 ° C cooling air is about 1.0 ~
When sprayed from the maximum side (S ₁ ) side of the modified cross-section hollow fiber at a speed of 8.0 m / sec, the properties of the present invention such as bulkiness, impact resilience, recovery, heat retention, and drapability are extremely excellent. A hollow fiber having a modified cross section can be obtained. Further, in producing a modified cross-section hollow fiber such as polyethylene terephthalate by the method of the present invention, of course, spinning may be performed at a higher speed than the above.

Further, when the fiber is stretched during spinning and / or after the fiber is once wound up, a higher potential crimping ability is imparted to the modified cross-section hollow fiber. The stretching method and the stretching conditions in that case can be adopted known methods conventionally used and the stretching conditions suitable for each polymer. For example, the stretching treatment after spinning includes water bath stretching, hot air stretching, and heating plate. It can be carried out by the contact stretching used or other method. Among them, water bath drawing is preferable from the viewpoint of physical properties of fibers. In the case of a modified cross-section hollow fiber having latent crimping ability,
By expressing crimps, higher bulkiness, impact resilience, recoverability, heat retention, drapability and the like can be obtained. However, crimps are expressed depending on the application and usage of the fiber. It can be carried out as it is, after being cut into staples or the like, or after the fibers are filled into the skin or the mold. In order to develop the crimp, methods such as warm air heating, indirect heating with a heater or the like, liquid heating and the like can be adopted.

The modified cross-section hollow fiber produced as described above may be used as it is in the form of long fibers (filament) in the production of fabrics, or may be cut into staples and used. When used as a cushioning material or a cushioning material, the characteristics such as good separability, openability, bulkiness, impact resilience, recoverability and heat retention can be fully utilized. When the modified cross-section hollow fiber of the present invention is used as a stuffed cotton or cushioning material in the form of staple,
The development of crimps may be performed before filling the epidermis or the mold as described above, or after filling.

[0042]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following examples, the intrinsic viscosity [η] of the polyester resin (polyethylene terephthalate), the fiber open ratio and the specific volume were determined as follows.

<< Intrinsic viscosity of polyester resin [η] >>
1,1,2,2-tetrachloroethane / phenol mixed solvent (1: 1) in 10 cc of polyester resin sample 0.1
After dissolving 000 g, the viscosity was measured using a Ubbelohde viscometer, and the intrinsic viscosity [η] was determined from the following formula.

[0044]

[Equation 1] Intrinsic viscosity [η] = (1/4) × η _sp + (3 /
4) × ln (η _sp +1) where η _{sp is the} specific viscosity

<< Fiber opening ratio >> Fiber opening processing was performed using a turbo opener type opening machine, and the fiber opening ratio (%) was determined by the following formula.

[0046]

[Equation 2] Opening ratio (%) = {(weight of raw cotton in opening after opening) /
(Raw cotton weight when unopened)} × 100

<< Specific Volume of Fiber >> The specific volume of the fiber was determined by the following formula.

[0048]

[Equation 3] Specific volume of fiber (cm ³ / g) = (S × H) / W In the formula, H: bulk (cm) when initial load (0.5 g / cm ² ) is applied W: test piece Weight (g) S: Area of the surface of the test piece to which the load is applied (cm ² ).

Cushions or comforters were manufactured using the fibers (staple fibers) obtained in the following Examples or Comparative Examples, and their bulkiness, impact resilience, and recoverability were evaluated according to the evaluation criteria shown in Table 1 below. It was evaluated according to.

[0050]

[Table 1]  Criteria for characterizing cushions or comforters Bulkiness : ◎: Specific volume 115 cm³/ G or more, which is extremely good O: Specific volume is 100 cm³/ G or more 115 cm³</ G
Is good. Δ: Specific volume is 85 cm.³/ G or more 100 cm³</ G
Yes, bad x: Specific volume of 85 cm³</ G, extremely poorImpact resilience : ⊚: Compressibility is 60% or more and extremely good ◯: Compressibility is 50% or more and less than 60%, good Δ: Compressibility is 40% or more and less than 50%, poor ×: Compressibility is 40 %, Which is extremely poorResilience : ⊚: Recovery rate is 95% or more and extremely good ∘: Recovery rate is 90% or more and less than 95%, good Δ: Recovery rate is 85% or more and less than 90%, poor ×: Recovery rate is 85 %, Which is extremely poor

Example 1 (1) A spinning nozzle (Cr) having polyethylene terephthalate (PET) having an intrinsic viscosity [η] of 0.60 and having five linear slits (B ₁ ) shown in (a) of FIG. = 1.4m
m, Cw = 0.2 mm, Ah = 0.25 mm, Aw = 0.
15 mm, Bh = 0.6 mm, Bw = 0.2 mm, Dw =
0.2 mm, θ ₁ = 120 °, θ ₂ = θ ₃ = 60 °, a =
^{0.075mm 2, b = 0.240mm 2,} a / b = 0.
From the spinneret with 186 313)
2. Melt spinning was performed at a rate of 2.2 g / min at a discharge rate per spinning nozzle of 2.2 ° C., and a cooling air of 24 ° C. was fed from the direction of the connecting portion (D) of the spinning nozzle at a position 4 to 24 cm immediately below the spinneret.
A raw yarn was produced by spraying at a wind speed of 8 m / sec, spinning draft 457, and spinning at a take-up speed of 600 mm / min. The obtained spun raw yarn is converged, and the temperature is set to 92 according to a conventional method.
Stretching in a water bath at ℃ (stretching ratio 4.75), crimping (developing crimping), drying, cutting, fiber length 32 m
A modified hollow fiber staple having a substantially pentagonal cross-sectional shape of m, single fiber fineness of 9.05 denier was produced.

(2) The cross-sectional shape of the modified cross-section hollow fiber obtained in the above (1) is a shape as shown in FIG. 1 (a), which is a hollow substantially pentagonal shape and has the largest side portion. The radius of curvature (r) of (S ₁ ) is 18.7 μm, and the height (H) with respect to the width (W) of the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) at the _five vertices of the substantially pentagon. ) Ratio (H / W) is 0.65
It was 0.71. Further, when the open ratio and specific volume of the modified cross-section hollow fiber staple were measured by the above-mentioned method, the open ratio was 98.7% and the specific volume was 123.8 cm ^3.
/ G.

(3) The hollow fiber staple having a modified cross section obtained as described above was blown with air into a breathable outer cover for cushion of length × width = 45 cm × 45 cm with a basis weight of 0.15 g / cm ² . When the bulkiness, impact resilience and recoverability of the resulting cushion were evaluated by the above-mentioned method,
As shown in Table 2 below, all were extremely good.
Further, during the production of the cushion, when the fibers are blown into the outer skin for the cushion, the hollow fiber staples having a modified cross section have excellent separability and openability, so that no entanglement between fibers or agglomeration occurs at all. The fibers could be blown into the outer skin very smoothly with good workability.

Example 2 (1) A spinning nozzle (Cr = 1.4 mm) having five PETs having an intrinsic viscosity [η] of 0.60 and having linear slits (B ₁ ) shown in FIG. 3B. , Cw = 0.2 mm, Ah =
0.25 mm, Aw = 0.15 mm, Bh = 0.6 mm,
Bw = 0.2 mm, Dw = 0.2 mm, θ ₁ = 100 °,
θ ₂ = θ ₃ = 65 °, a = 0.075 mm ² , b = 0.2
40 mm ² , a / b = 0.313) was melt-spun from 186 spinnerets at a temperature of 280 ° C. and a discharge rate of 2.2 g / min per spinning nozzle, and immediately below the spinneret.
At 24 cm, a cooling air at 24 ° C. was blown from the direction of the connecting portion (D) of the spinning nozzle at a wind speed of 7.0 m / sec, and spinning was performed at a spinning draft 457 and a take-up speed of 600 mm / min to produce a raw yarn. The obtained spun raw yarn is converged, drawn in a water bath at a temperature of 92 ° C. according to a conventional method (drawing ratio 3.56), crimped (developed), dried and cut to obtain a fiber length. A substantially pentagonal modified cross-section hollow fiber staple having a diameter of 32 mm and a single fiber fineness of 12.03 denier was manufactured.

(2) The cross-sectional shape of the modified cross-section hollow fiber obtained in the above (1) is a shape as shown in FIG. 1 (b), which is a hollow substantially pentagonal shape and has the largest side. The radius of curvature (r) of the portion (S ₁ ) is 10.9 μm, and the protrusions (E ₁ , E ₂ , E ₃ , E ₄ ,
The ratio (H / W) of the height (H) to the width (W) of E ₅ ) was 0.93 to 0.97. Further, when the open ratio and specific volume of this modified hollow fiber staple were measured by the above-mentioned method, the open ratio was 98.2% and the specific volume was 12%.
It was 6.4 cm ³ / g.

(3) Using the modified cross-section hollow fiber staple obtained in (1), blow molding was carried out in the same manner as in (3) of Example 1 to produce a cushion. When the bulkiness, impact resilience and recovery of the obtained cushion were evaluated by the above-mentioned methods, all were extremely good as shown in Table 2 below. Further, in manufacturing the cushion, due to the good separability and openability of the modified cross-section hollow fiber staple, when the fibers are blown into the outer skin for the cushion, there is no formation of fiber lumps and the blowing operation is extremely smooth. I was able to.

Example 3 (1) Spinning nozzle (Cr = 1.4 mm) having 7 linear slits (B ₁ ) shown in FIG. 3 (c) of PET having an intrinsic viscosity [η] of 0.63 , Cw = 0.2 mm, Ah =
0.35 mm, Aw = 0.15 mm, Bh = 0.6 mm,
Bw = 0.2 mm, Dw = 0.2 mm, θ ₁ = 130 °,
θ ₄ = θ ₅ = θ ₆ = θ ₇ = 30 °, a = 0.053 mm ² ,
b = 0.092 mm ² , a / b = 0.576) 186
Melt spinning was performed at a temperature of 295 ° C. and a discharge rate per spinning nozzle of 2.4 g / min from the individually spun spinneret, and at a position 4 to 24 cm directly below the spinneret from the direction of the connecting portion (D) of the spinning nozzle, 24 Chilling cooling air is blown at a wind speed of 1.3 m / sec, spinning draft 730, take-up speed 900
A raw yarn was produced by spinning at mm / min. The obtained spun raw yarn is converged, stretched in a water bath at a temperature of 92 ° C. (stretching ratio 4.94) according to a conventional method, and after crimping (developing), a silicone resin-based oil agent is added, By drying and cutting, a substantially pentagonal modified cross-section hollow fiber staple having a fiber length of 32 mm and a single fiber fineness of 6.31 denier was manufactured.

(2) The cross-sectional shape of the substantially pentagonal modified cross-section hollow fiber obtained in the above (1) has a shape as shown in (c) of FIG. 1 and has a maximum side portion (S ₁ ). Has a radius of curvature (r) of 25.9 μm, and the ratio of the height (H) to the width (W) of the protrusions (E ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) at the _five vertices of the substantially pentagon (( H / W) was 0.82 to 0.91. Further, when the open ratio and specific volume of this modified cross-section hollow fiber staple were measured by the above-described method, the open ratio was 99.1% and the specific volume was 136.2 cm ³ / g. (3) A quilt was manufactured by filling the hollow fiber staple having the modified cross section obtained above into an outer cover for a quilt at a bulk density of g / cm ³ . The quilt thus obtained was evaluated for bulkiness, impact resilience and recoverability by the methods described above.
It was extremely good as shown in. The comforter was also excellent in heat retention and drape.

Comparative Example 1 (1) Intrinsic viscosity [η] of 0.64 and titanium dioxide of 0.
A C-shaped slit (Cr = 1.4 mm, Cw = 0.2 mm, Dw = Dw = shown in FIG.
0.2 mm) from the spinneret with 248 holes
Melt spinning was performed at 0 ° C. and a discharge rate of 2.1 g / min per spinning nozzle, and cooling air of 24 ° C. was 1.2 m from the direction of the connecting portion (D) of the spinning nozzle at a position 4 to 24 cm immediately below the spinneret. Spraying draft 346, with a wind speed of
A yarn was produced by spinning at a take-up speed of 1100 mm / min. The obtained spun raw yarn is converged, stretched in a water bath at a temperature of 92 ° C. (stretching ratio 2.83) according to a conventional method, crimped (developed), dried and cut to obtain a fiber length. 32m
m, single fiber fineness of 7.87 denier hollow fiber staples were produced.

(2) Most of the cross-sectional shape of the hollow fiber obtained in the above (1) had a circular hollow cross-sectional shape as shown in FIG. The flattened hollow cross-sectional shape fibers as shown in FIG. The hollow staple obtained has an opening ratio of 92.6%, a specific volume of 85.4 cm ³ / g, and the irregular shape of the present invention having the substantially pentagonal cross-sectional shape obtained in Examples 1 to 3 above. Both the open ratio and the specific volume were low and inferior to the cross-section hollow fiber.

(3) Using the hollow fiber staple obtained in the above (1), blow molding was carried out in the same manner as in (3) of Example 1 to produce a cushion, and the bulkiness of the obtained cushion was obtained. When the impact resilience and recoverability were evaluated by the above-mentioned methods, they were all inferior as shown in Table 2 below.

Comparative Example 2 (1) A spinning nozzle (Cr = 1.4 mm) having 5 linear slits (B ₁ ) shown in FIG. 4 (b) of PET having an intrinsic viscosity [η] of 0.60. , Cw = 0.2 mm, Ah =
0.17mm, Aw = 0.17mm, Bh = 0.18m
m, Bw = 0.2 mm, Dw = 0.2 mm, θ ₁ = 120
°, θ ₂ = θ ₃ = 60 °, a = 0.058 mm ² , b =
0.072 mm ² , a / b = 0.806) was melt-spun at a temperature of 280 ° C. and a discharge amount per spinning nozzle of 2.2 g / min from 186 spinnerets, and 4 to 4 directly below the spinneret. At 24 cm, a cooling air of 24 ° C. was blown from the direction of the connecting portion (D) of the spinning nozzle at a wind speed of 2.0 m / sec, and spinning was performed at a draft 532 and a take-up speed of 600 mm / min to produce a raw yarn. The obtained spun raw yarn is converged, stretched in a water bath at a temperature of 92 ° C. according to a conventional method (stretching ratio 5.43), crimped (developed), and then dried.
It was cut to produce a modified staple fiber having a fiber length of 32 mm and a single fiber fineness of 7.97 denier.

(2) The cross-sectional shape of the modified cross-section fiber obtained in (1) above is a cut shape as shown in (b) of FIG. 5 and is not a closed hollow shape. The ratio of the height (H) to the width (W) of the five protrusions (H /
W) was 0.79 to 1.13. Further, when the spread ratio and specific volume of this modified cross-section fiber staple were measured by the above-mentioned method, the spread ratio was 97.3% and the specific volume was 8%.
It is 7.1 cm ³ / g, and compared with the modified cross-section hollow fiber of the present invention having the substantially pentagonal cross-sectional shape obtained in the above Examples 1 to 3, both the open ratio and the specific volume are low. ,
It was inferior. Also, using the modified cross-section fiber staple obtained in (1) above, in the same manner as in (3) of Example 1,
The cushion was manufactured by blow molding, and the bulkiness, impact resilience, and recoverability of the obtained cushion were evaluated by the methods described above, and as shown in Table 2 below, they were all inferior.

Comparative Example 3 (1) A spinning nozzle (Cr = 1.4 mm) having 11 linear slits (B ₁ ) shown in FIG. 4 (c) of PET having an intrinsic viscosity [η] of 0.62. , Cw = 0.2 mm, Ah =
0.25 mm, Aw = 0.15 mm, Bh = 0.6 mm,
Bw = 0.2 mm, Dw = 0.2 mm, θ ₁ = 90 °, a
^{= 0.075mm 2, b = 0.240mm 2} , a / b =
0.313) from the spinneret with 186 holes
Melt spinning was performed at 5 ° C. and a discharge rate of 2.2 g / min per spinning nozzle, and cooling air at 24 ° C. was 2.0 m from the direction of the connecting portion (D) of the spinning nozzle at 4 to 24 cm immediately below the spinneret. / Second blowing speed, spinning draft 648,
A yarn was produced by spinning at a take-up speed of 600 mm / min. The obtained spun raw yarn is converged, stretched in a water bath at a temperature of 92 ° C. (stretching ratio 5.23) according to a conventional method, crimped (developed), dried and cut to obtain a fiber length. 32m
m, single-filament fineness of 8.21 denier was produced.

(2) The cross-sectional shape of the modified cross-section hollow fiber obtained in (1) above is a substantially pentagonal modified cross-section hollow shape as shown in FIG. The radius of curvature is 7.4 μm, and the five protrusions (E
The ratio (H / W) of the height (H) to the width (W) of ₁ , E ₂ , E ₃ , E ₄ , E ₅ ) was 0.51 to 0.54.
Further, when the spread ratio and specific volume of this modified cross-section fiber staple were measured by the above-mentioned method, the spread ratio was 92.9.
%, The specific volume is 86.8 cm ³ / g, and the open ratio and the specific volume are higher than those of the modified cross-section hollow fibers having the substantially pentagonal cross-sectional shape of the present invention obtained in Examples 1 to 3 above. Both were low and inferior. Further, using the modified cross-section fiber staple obtained in (1) above, blow molding was performed in the same manner as in (3) of Example 1 to produce a cushion, and the obtained cushion had bulkiness and impact resilience. When the recoverability was evaluated by the above-mentioned method, all were inferior as shown in Table 2 below.

Comparative Example 4 (1) The number of linear slits (B ₁ ) arranged toward the outside of the C-shaped slit (C) is four, and the four linear slits (B ₁ ) are C. One spinning nozzle having the same shape and dimensions as the spinning nozzle used in Example 1 except that the spinning nozzles are arranged at substantially equal intervals along the outer periphery of the character-shaped slit (C).
Melt spinning (spinning draft 418) was performed in the same manner as in Example 1 by using 86 spinnerets, and stretching, crimping, drying and cutting were performed to produce a modified cross-section hollow fiber staple. The cross-sectional shape of was a substantially quadrangular hollow shape. (2) The modified hollow fiber staple obtained in (1) above has an opening ratio of 93.7% and a specific volume of 99.6 cm ³ /
g, and although the opening ratio and the specific volume were somewhat higher than those of the staples of Comparative Examples 1 to 3 described above, Examples 1 to 3 were used.
Compared with the modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape of the present invention obtained in 1., both the open ratio and the specific volume were low and inferior. Further, using the modified cross-section fiber staple obtained in (1) above, blow molding was performed in the same manner as in (3) of Example 1 to produce a cushion, and the obtained cushion had bulkiness and impact resilience. When the recoverability was evaluated by the above-mentioned method, it was not sufficiently satisfactory as shown in Table 2 below.

<< Comparative Example 5 >> (1) 2 sandwiching the connecting portion (D) of the C-shaped slit (C)
One of the angle of the linear slits (B ₁₎ (θ ₁₎ is 150 °
Melt spinning, drawing, crimping, drying and cutting were carried out in the same manner as in Example 1 using a spinneret having 186 spinning nozzles having the same shape and dimensions as in Example 1 except that A substantially pentagonal irregular cross-section hollow fiber staple (single fiber fineness 8.18 denier) having a cross-sectional shape similar to that of FIG. The radius of curvature of the maximum side portion (S ₁ ) of this fiber was 35 to 50 μm, and the hollow portion was crushed in about 20 to 30% of the obtained fiber, and the hollow ratio was significantly reduced. (2) The open ratio of the modified cross-section hollow fiber staple obtained in (1) above is 92.9%, and the specific volume is 91.8 cm ³ /
g, and both the open ratio and the specific volume were low and inferior to the modified cross-section hollow fiber of the present invention having the substantially pentagonal cross-sectional shape obtained in Examples 1 to 3. Further, using the modified cross-section fiber staple obtained in (1) above, blow molding was performed in the same manner as in (3) of Example 1 to produce a cushion, and the obtained cushion had bulkiness and impact resilience. When the recoverability was evaluated by the above-mentioned method, all were inferior as shown in Table 2 below.

Comparative Example 6 (1) A spinning nozzle (Cr = 1.4 mm) having seven linear slits (B ₁ ) shown in FIG. 4D of PET having an intrinsic viscosity [η] of 0.63. , Cw = 0.2 mm, Ah =
0.10mm, Aw = 0.13mm, Bh = 0.38m
m, Bw = 0.14 mm, Dw = 0.2 mm, θ ₁ = 13
0 °, θ ₄ = θ ₅ = θ ₆ = θ ₇ = 30 °, a = 0.026 m
m ² , b = 0.106 mm ² , a / b = 0.245) 1
Melt spinning was performed at a temperature of 280 ° C. and a discharge rate of 2.2 g / min per spinning nozzle from 86 spinnerets, and from the direction of the connecting portion (D) of the spinning nozzle at a position 4 to 24 cm immediately below the spinneret. A cooling air of 24 ° C. is blown at a wind speed of 1.3 m / sec, a spinning draft 698, and a take-up speed of 900
A raw yarn was produced by spinning at mm / min. The obtained spun raw yarn is converged, stretched in a water bath at a temperature of 92 ° C. (stretching ratio 7.04) according to a conventional method, crimped (developed), dried and cut to obtain a fiber length. 32 mm, single fiber fineness 6.
A 09 denier modified cross-section fiber staple was produced.

(2) The cross-sectional shape of the modified cross-section fiber obtained in (1) above is a cut shape as shown in (d) of FIG. 5 and does not have a closed hollow shape. , And the ratio of the height (H) to the width (W) of the seven protrusions (H /
W) was 0.83 to 1.18. Further, when the opening ratio and specific volume of this irregularly shaped cross-section fiber staple were measured by the above-mentioned method, the opening ratio was 91.0% and the specific volume was 8
8.8 cm ³ / g, compared to the modified cross-section hollow fiber of the present invention having the substantially pentagonal cross-sectional shape obtained in Examples 1 to 3, both the open ratio and the specific volume are low, It was inferior. Further, using the modified cross-section fiber staple obtained in (1) above, blow molding was performed in the same manner as in (3) of Example 1 to produce a cushion, and the obtained cushion had bulkiness and impact resilience. When the recoverability was evaluated by the above-mentioned method, all were inferior as shown in Table 2 below.

[0070]

[Table 2]

[0071]

INDUSTRIAL APPLICABILITY The modified cross-section hollow fiber of the present invention having the substantially pentagonal cross-sectional shape satisfying the above requirements (i) to (iii) provides bulkiness, impact resilience, recoverability, heat retention and drapeability. Very good. And, the modified cross-section hollow fiber of the present invention is excellent in separability and openability and does not form a fiber lump, so when used as a stuffed cotton or cushioning material, by air blowing or other means, It can be filled into the outer skin and the mold smoothly and evenly with extremely good workability, and has the above-mentioned good bulkiness, impact resilience, and
Combined with various characteristics such as recoverability, heat retention and drape,
Various products such as futons, stuffed products, and cushions having extremely excellent characteristics can be manufactured. Further, in the case of the spinning method of the present invention in which a fiber-forming thermoplastic polymer is melt-spun using a spinneret provided with a spinning nozzle having the above requirements (1) to (5), it has a substantially pentagonal shape having the above-mentioned excellent properties. A hollow fiber having a modified cross section can be manufactured extremely smoothly. In performing the spinning method of the present invention, in particular, while blowing the cooling air on the fibers discharged from the spinning nozzle from the direction of the maximum side portion (S ₁ ) [direction of the connecting portion (D) of the spinning nozzle]. When spinning is performed, a difference in the internal structure between the maximum side portion (S ₁ ) and the other side portions can be produced, and a modified cross-section hollow fiber having a high potential crimping ability can be obtained.

[Brief description of drawings]

FIG. 1 is a view showing an example of a cross-sectional shape of a modified cross-section hollow fiber of the present invention.

FIG. 2 is a diagram showing the content of each part in a cross section of the modified cross-section hollow fiber of the present invention, a measuring method, and the like.

FIG. 3 is a view showing an example of the shape of a spinning nozzle of a spinneret used for producing a modified cross-section hollow fiber of the present invention.

FIG. 4 is a view showing the shape of a spinning nozzle in a spinneret used in Comparative Example 1.

FIG. 5 is a view showing a cross-sectional shape of each fiber obtained in Comparative Examples 1, 2, 3 and 6.

[Explanation of symbols]

A ₁ C-shaped slits (C) are connected to each other with a connecting portion (D) sandwiched therebetween. B ₁ C-shaped slits (C) are connected to linear slits facing outward. C Spinning nozzle C-shaped slits D Connection between both ends of the C-shaped slit E ₁ Projection at the apex of the modified cross section hollow fiber E ₂ Projection at the apex of the modified cross section hollow fiber E ₃ Projection at the apex of the modified cross section hollow fiber E ₄ Modified Projection at the top of cross-section hollow fiber E ₅ Projection at the top of cross-section hollow fiber S ₁ Maximum side of modified cross-section hollow fiber S ₂ Side of modified cross-section hollow fiber S ₃ Side of modified cross-section hollow fiber S ₄ Side of hollow fiber with irregular cross section S ₅ Side of hollow fiber with irregular cross section

Claims (12)

[Claims] 1. A modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape, the cross-sectional shape of which is (i) to
(Iii) Requirements; (i) One maximum side (S ₁ ) and four shorter sides (S ₂ , S ₃ , S ₄ , S ₅ ), which are the maximum sides. part (S ₁₎ one end from the side portion in the order of (S _2), side portions (S _3), sides (S ₄₎ and side portions (S ₅₎ is outermost sized sides of the (S ₁₎ It is connected to the other end to form a hollow substantially pentagonal shape; (ii) the largest side (S ₁ ) is curved toward the inside of the fiber with a radius of curvature of 10 to 30 μm. And (iii) at each of the five vertices of the above-mentioned substantially pentagonal shape, a protrusion having a ratio (H / W) of height (H) to width (W) of 0.6 to 1.0 is provided. A cross-section hollow fiber having a substantially pentagonal cross-section, which has a cross-section satisfying 2. The length of the side portion (S ₂ ) and the side portion (S ₅ ) and the length of the side portion (S ₃ ) and the side portion (S ₄ ) are at least substantially the same. A hollow fiber having a modified cross section according to claim 1. 3. The modified cross-section hollow fiber according to claim 1, further comprising one or two protrusions on one or more of the side portion (S ₂ ) to the side portion (S ₅ ). 4. The opening rate after opening with a turbo opener type opening machine is 95.0% or more, and the specific volume is 105 cm.
The modified cross-section hollow fiber according to any one of claims 1 to 3, which has a content of ³ / g or more. 5. The internal structure in the maximum side part (S ₁ ) is different from the internal structure in the remaining side parts (S ₂ ) to side parts (S ₅ ), which has high latent crimpability. 4. A hollow fiber having a modified cross section according to any one of items 4 to 4. 6. The modified cross-section hollow fiber according to claim 5, wherein crimps are expressed. 7. A method for producing a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape by melt-spinning a fiber-forming thermoplastic polymer, the spinning nozzle having the following requirements provided in a spinneret: It has a C-shaped slit, and two parallel slits (A ₁ , A ₁ ) are connected to the C-shaped slit inwardly with a connecting portion between both ends of the C-shaped slit sandwiched therebetween. ; 5 to 9 linear slits (B ₁ ) are connected to the C-shaped slit with the connecting portion of the C-shaped slit sandwiched therebetween, and are connected to the C-shaped slit outwardly; Of the two linear slits (B
_The angle (θ ₁ ) formed by ₁ , B ₁ ) is 100 ° to 130 °;
When the area of the slit (A ₁ ) is a and the area of the linear slit (B ₁ ) is b, a / b is 0.3 to 0.6; A method for producing a modified cross-section hollow fiber having a substantially pentagonal cross-sectional shape, which comprises discharging a hydrophilic thermoplastic polymer and spinning the polymer. 8. The manufacturing method according to claim 7, wherein 5 to 9 linear slits (B ₁ ) in the spinning nozzle are provided in line symmetry with respect to a straight line passing through the center of the connecting portion of the C-shaped slits. 9. The high latent crimpability is imparted to the fibers by blowing cooling air to the fibers discharged from the spinning nozzle from the direction of the maximum side (S ₁ ) connecting portion.
Manufacturing method. 10. The production method according to claim 9, further comprising performing crimping and cutting into staples after stretching is performed during spinning and / or after winding of the fiber. 11. A stuffed cotton comprising the modified cross-section hollow fiber according to any one of claims 1 to 6. 12. A cushion material comprising the modified cross-section hollow fiber according to any one of claims 1 to 6.