JP2011208336A - Dope-dyed black composite staple fiber, and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dope-dyed black composite staple fiber substantially not generating the delamination and the splitting of components constituting the composite fiber in a process of producing nonwoven fabric, but generating the delamination and splitting for the first time by a subsequent water-stream jetting treatment.SOLUTION: The composite staple fiber of a laminated type which contains carbon black in both or one of a high molecular weight polymer component (A) and a high molecular weight polymer component (B), and in which alternately disposed in the fiber cross-section, satisfies all of the following conditions: (1) (B) is completely covered with (A), and (B) and (A) excluding the part thereof covering (B) each present a substantially flat shape, (2) the end parts of (B) in the long-side direction thereof each have an arcuate shape and are disposed inside the surface of the fiber within a distance of 0.05 to 1.5 μm from the fiber surface, (3) the mass ratio of (A) to (B) is from 9/1 to 1/9, and (4) the thicknesses (D) of (A) and (B) in the short-side direction thereof are each 3 μm or less, and the ratio (L/D) of the length (L) of each of both components in the long-side direction thereof relative to the thickness (D) thereof in the short-side direction thereof is 2 or greater.

Description

  The present invention is a composite component that exhibits a sufficient coloring effect and does not substantially cause peeling or splitting between components constituting the composite fiber in the nonwoven fabric production process, and is only performed by a physical division process such as a subsequent water jet process. The present invention relates to a black original composite fiber that causes separation and splitting between the two, and a method for producing the same.

  In order to produce an ultrafine fiber having a single fiber fineness of 0.1 dtex or less, a thread breakage is likely to occur, and thus a composite spinning means has been conventionally used. The cross-sectional form of the composite fiber for forming the ultrafine fiber is (1) a composite form such as a multi-layer type composite fiber or petal type composite fiber in which two components are highly divided and interleaved, and (2) one component is in the other components And highly dispersed sea-island type composite fibers. In the former composite fiber, an ultrafine fiber with sharp edges and an extraordinary ultrafine fiber are formed by the separation of the components, and various applications are developed using each form.

  As such a conjugate fiber, there are many examples of conjugate fibers mainly of nylon 6 and polyethylene terephthalate (PET), but in order to obtain ultrafine fibers by peeling and dividing both components, (1) benzyl alcohol A method of shrinking nylon components with such chemicals and separating them from each other with force, (2) A method of dissolving PET in an alkaline aqueous solution and separating them from each other, and (3) Wet heat treatment and drying treatment many times There are a method of repeatedly peeling, (4) a method of forcibly separating by forcibly rubbing, or (5) a combination thereof.

  When the above-mentioned composite fiber is used as a black yarn, a colorant such as carbon black is used, and the process of dyeing the yarn by post-processing is added for manufacturing. When performing these treatments, it is necessary to add a dyeing process, and as problems there are complicated processes, use of a large amount of chemicals and energy, and increase in manufacturing costs such as dyeing wastewater treatment being necessary, and It was also necessary to consider the environmental impact. Further, in the work of dyeing, since dye molecules could not enter the crystalline part of the fiber, the dye molecules entered only the amorphous part and were colored. For this reason, there are problems such as fading easily or inability to color more uniformly.

  As a countermeasure against these, various methods of incorporating carbon black into the above-described composite fiber have been studied (for example, see Patent Documents 1 and 2). It is disclosed that ultrafine fibers having a sufficient coloring effect can be obtained from the composite fibers containing carbon black.

  However, the composite fibers containing the carbon blacks of Patent Documents 1 and 2 can obtain a dark color effect, but when these composite fibers are refined by extraction or divided peeling, they are caused by the cross-sectional shape to give glare. There was a problem that the color unevenness was conspicuous.

  Furthermore, when producing a nonwoven fabric or spun yarn using the composite fiber containing carbon black of Patent Documents 1 and 2 as a raw material, peeling occurs between the components of the composite fiber in the card process, and the fineness is reduced, There was a problem that Nep occurred. Further, when needle punching is performed to entangle the fibers, there is a problem that separation occurs due to damage, the single fibers are hardly entangled, and the peel strength of the nonwoven fabric is not improved. As a countermeasure, conventionally, a bonded type composite fiber has been proposed, but a method of incorporating carbon black in the composite fiber of this shape has not yet been reported.

JP 2008-088562 A JP 2008-184725 A

  Therefore, an object of the present invention is to exhibit a sufficient coloring effect, and in the non-woven fabric manufacturing process, there is substantially no separation / split between the components constituting the composite fiber, and a physical division process such as a subsequent water jet process. Thus, for the first time, a black original composite staple fiber in which peeling and splitting between composite components occurs is provided.

  As a result of intensive studies to solve the above problems, the present inventors have found that in the composite fiber composed of the polymer component (A) and the polymer component (B), the polymer components (A) and (B) ) And a composite fiber having a bonded composite form in which one or both of them contain a predetermined amount of carbon black and melt-spun using both components of the polymer exhibit a sufficient coloring effect and produce a nonwoven fabric. It has been found that peeling and splitting between components constituting the composite fiber are not substantially generated in the process, and peeling and splitting between the composite components are first caused by a subsequent physical division treatment such as water jet treatment. Was completed.

That is, in the present invention, carbon black having an average primary particle size of 5 to 50 nm is 0.1 to 10% by mass in both or either of the polymer component (A) and the polymer component (B). And a staple fiber having a bonded composite form in which the polymer component (A) and the polymer component (B) are alternately arranged in the cross section of the fiber, the following (1) It is a composite staple fiber satisfying all of (4) to (4).
(1) The polymer component (B) is completely covered with the polymer component (A), and the polymer component (A) other than the polymer component (B) and the coating portion. Is substantially flat,
(2) The long-side tip of the polymer component (B) has a circular cross-sectional shape and is located 0.05 to 1.5 μm inside from the fiber surface;
(3) The mass ratio of the polymer component (A) and the polymer component (B) is 90/10 to 10/90,
(4) In the said fiber cross section, the thickness (D) of the short side direction of a polymer component (A) and a polymer component (B) is 3 micrometers or less, respectively, and a polymer component (A) ), (B) The ratio (L / D) of the length (L) in the long side direction to the thickness (D) in the short side direction in both components is 2 or more.

  Furthermore, the present invention is preferably the above composite staple fiber in which the polymer component (A) is a polyester and the polymer component (B) is a fiber-forming polyolefin polymer or polyamide polymer. is there.

  The present invention is a fiber structure containing 20% by mass or more of the composite staple fiber, wherein at least one interface between the polymer component (A) and the polymer component (B) of the composite staple fiber is at least one. A part of the polymer polymer component (A) is peeled off to form an acute edge structure having a protruding shape in the cross section at the end in the long side direction, and fibers constituting the nonwoven fabric are entangled with each other. It is a fiber structure, preferably a fiber structure in which the fiber structure is a dry nonwoven fabric or a wet nonwoven fabric, more preferably a fiber structure that is entangled and integrated with a woven fabric or a knitted fabric, and further a wiper material or It is a fiber structure which is a base fabric for artificial leather.

  According to the present invention, a composite staple fiber having excellent colorability can be obtained, and a flat single yarn can be obtained by splitting the fiber, and a woven fabric, a knitted fabric, and a nonwoven fabric containing the fiber. In the case of the above, an ultrafine fiber structure having a large surface area can be obtained, and the ultrafine fiber structure can obtain an excellent effect in terms of sound absorption.

Hereinafter, the present invention will be described in detail.
The composite staple fiber of the present invention is a staple fiber having a bonded composite form in which the high molecular weight polymer component (A) and the high molecular weight polymer component (B) are alternately arranged in the fiber cross section, for example, As shown in FIG. 1, the polymer component (B) is completely covered with the polymer component (A), and the polymer component (A) is present on the entire outer periphery of the fiber cross section. is important. When the polymer component (B) is not covered with the polymer component (A), for example, in the card processing or needle punch processing in the nonwoven fabric manufacturing process or the like, at the interface of the composite component in the longitudinal direction of the fiber Peeling and splitting will occur.

  In the composite staple fiber of the present invention, the mass ratio of the polymer component (A) and the polymer component (B) needs to be 90/10 to 10/90, and 85/15 to 15/85. It is preferable to do. When the mass ratio of the polymer component (B) is less than 10%, it becomes difficult to form the target cross section by alternately arranging the component (A) and the component (B) in the spin pack. When carbon black is added only to the polymer component (B), the coloring effect does not appear. On the other hand, when the mass ratio of the polymer component (B) exceeds 90%, the amount of the polymer component (A) is small, making it difficult to obtain the intended cross section and simultaneously covering the entire fiber surface. It becomes difficult.

  In the present invention, the high molecular weight polymer component (B) and the high molecular weight polymer component (A) other than the covering portion have a substantially flat shape when viewed in the fiber cross section, and in the fiber cross section, It is important that the long-side tip of the molecular polymer component (B) has an arc shape in cross section and is located 0.05 to 1.5 μm inside from the fiber surface. When the tip of the long side direction of the polymer component (B) is thinner than 0.05 μm, the coating portion is abraded in the card process or the needle punch process, and the polymer component (A) and the polymer weight The coalesced component (B) peels and splits, so that the process for producing the nonwoven fabric deteriorates. On the other hand, if it exceeds 1.5 μm, peeling and splitting can be sufficiently prevented in the card process and needle punching process, but it is difficult to split when splitting and splitting by subsequent hydroentanglement processing etc. Become.

In the present invention, a fiber structure such as a nonwoven fabric containing composite staple fibers is subjected to splitting treatment by physical means such as hydroentanglement, whereby ultrafine fibers comprising the polymer component (A) and polymer weight are polymerized. Although the ultrafine fiber which consists of a unification component (B) is formed, for example, when the performance at the time of using a wiper and the texture and coloring property at the time of using artificial leather are taken into consideration, both the high molecular weight polymer components (A) and (B) It is important to have a flat cross section.
For example, in obtaining high-quality artificial leather using the composite staple fiber of the present invention, in a raised product such as suede or nubuck, the thinner the short fiber, the better the feeling of touch. It is preferable to use fibers thinner than 0.1 dtex, that is, fibers thinner than a fiber diameter of about 3 μm. Therefore, the monofilament of ultra-thin flat fibers composed of each of the high molecular weight polymer components (A) and (B) after splitting the composite staple fiber has a thickness (D in the short side direction shown in FIGS. 2 and 3). ) Is 3 μm or less. When it is thicker than 3 μm, the touch feeling may be deteriorated.

Furthermore, it is important that the fibers of the present invention have good color developability. For that purpose, the length (L) in the long side direction of the flat ultrafine fibers formed after the division shown in FIGS. It is important that the ratio (L / D) to the thickness (D) in the short side direction is 2 or more.
Further, the thinner the thin ultrathin fibers (D), the better the touch feeling, and the higher the L / D, the better the color development due to the dyeing, but the thinner (D) the finer the fineness. The color developability will not be improved if the is too small. Therefore, in order to improve the touch feeling and improve the color developability, it is preferable that the single fiber fineness of each divided flat ultrafine fiber is 0.02 dtex or more. The upper limit of the single fiber fineness is not particularly limited as long as it is within a range where the effect as an ultrafine fiber can be exhibited, but is preferably 0.6 dtex or less.

  The splitting and splitting of the composite staple fiber of the present invention is mainly performed by physical means such as high-pressure water flow treatment and buffing. This splitting and splitting is the length of the polymer component (B) in the cross section. It tends to occur from the apex in the shape of a substantially arc at both ends in the side direction, that is, from the thinnest portion of the coating portion made of the polymer component (A). And the cross section of the high molecular polymer component (A) formed by splitting has a form like the letter "I" of the capital letter of the alphabet as shown in FIG. Two projecting structures having a tapered shape are formed at both ends so as to extend in a direction substantially orthogonal (60 to 120 °) with the long side direction. This tapered protrusion structure is a structure derived from the remainder of the coating that has been split at the location where the coating portion made of the polymer component (A) has the smallest thickness.

  In the present invention, this tapered protrusion structure functions as an acute-angled edge. For example, when a wiper is used, a flat ultrafine fiber and a polymer-polymer component comprising the polymer-polymer component (A) formed by the acute-angle edge structure are used. The wiping property is further improved by incorporating dirt into the interfiber gap with the flat extra fine fiber made of (B).

  Furthermore, in the composite staple fiber of the present invention, carbon black having an average primary particle size of 5 to 50 nm is added to 0.1% or both of the polymer component (A) and the polymer component (B). It is important to contain 10% by mass. When the average primary particle size of the carbon black is less than 5 nm, there is a problem that sufficient darkness cannot be obtained, and when it exceeds 50 nm, the carbon black is not uniformly dispersed and color unevenness appears. There is. Further, when the carbon black content is less than 0.1% by mass, it becomes difficult to exhibit sufficient “tone” or “gloss”, and conversely, when it exceeds 10% by mass, the spinnability deteriorates and the fiber strength decreases. Arise. From the viewpoint of improving the light resistance of the fiber, the content of carbon black is preferably 1 to 10% by mass. Within this range, carbon black absorbs ultraviolet rays and has an effect of preventing deterioration of the polymer, and can exhibit a synergistic effect that can prevent a decrease in strength over time.

Next, the manufacturing method of the composite staple fiber of this invention is demonstrated below.
In the present invention, the polymer component (A) and the polymer component (B) are melted by separate melt extruders, and are alternately arranged by a conventional method and led to the spinneret. In particular, in the portion where the polymer component (B) and the wall surface in the spin pack are in contact with each other inside the spin pack, the end of the spin pack is caused by the surface tension of the polymer component (B). The composite staple fiber of the present invention in a form in which the entire outer periphery of the fiber cross section is covered with the polymer component (A) by being rounded and the polymer component (A) flowing into the gap is obtained. It is.
After being discharged from the spinneret, the composite staple fiber of the present invention can be obtained through processes such as drawing, crimping, drying and cutting by a conventionally known composite spinning fiber manufacturing technique.

  In the present invention, polymer polymer components (A) and (B) can be selected from the following polymer polymers according to the purpose and application. Examples include polyester polymers such as polyethylene terephthalate and polybutylene terephthalate, polyolefin polymers such as polyethylene and polypropylene, polyamide polymers such as nylon 6 and nylon 66, other polystyrene polymers, and polyvinyl alcohol. A polymer, an ethylene-vinyl alcohol-type polymer, etc. can be mentioned, 1 type or 2 types or more are used for each component.

  The polyethylene terephthalate polymer and polybutylene terephthalate polymer may have one or more of other dicarboxylic acid components, oxycarboxylic acid components, and other diol components as copolymerized units as necessary. good. In this case, the other carboxylic acid component includes aromatic dicarboxylic acids such as diphenyldicarboxylic acid and naphthalenedicarboxylic acid or ester-forming derivatives thereof; dimethyl 5-sodium sulfoisophthalate, bis (5-sodium sulfoisophthalate) (2- Metal sulfonate group-containing carboxylic acid derivatives such as hydroxyethyl); aliphatic dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid, dodecanedioic acid or ester-forming derivatives thereof. Examples of the oxycarboxylic acid component include p-oxybenzoic acid, p-β-oxyethoxybenzoic acid, or ester-forming derivatives thereof. Examples of the diol component include aliphatic diols such as diethylene glycol, 1,3-propanediol, 1,6-hexanediol, and neopentyl glycol; 1,4 bis (β-oxyethoxy) benzene, polyethylene glycol, polybutylene glycol, and the like. it can.

  The composite cross-sectional structure of the composite staple fiber of the present invention can be a multi-layer type, a hollow multi-layer type, a petal type, or a hollow petal type depending on the application and performance. It is preferable to use a multi-layered laminated composite cross-section fiber in which polymer components (A) and (B) are alternately laminated. Moreover, not only a round cross section but an irregular cross section fiber may be used.

  The single fiber fineness of the composite staple fiber of the present invention is not particularly limited, and can be arbitrarily selected depending on the application, for example, in the range of 0.5 to 30 dtex. Further, the cut length can be arbitrarily selected within the range of 1 to 20 mm depending on the application.

  Furthermore, various additives can be blended and used in the composite staple fiber of the present invention as required. For example, catalysts, anti-coloring agents, heat-resistant agents, flame retardants, optical brighteners, matting agents, coloring agents, gloss improvers, antistatic agents, fragrances, deodorants, antibacterial agents, acaricides, inorganic fine particles, etc. May be included. The additive may be blended in either one of the polymer components (A) and (B), or both.

  Next, the manufacturing method of the fiber structure containing the composite staple fiber of this invention is demonstrated. Basically, various optimum manufacturing methods may be adopted depending on the physical properties required for each application. For example, a raw cotton made of 20% by mass or more of composite staple fibers and other fibers is used, and this is carded. The fiber structure can be obtained by splitting and entanglement of the web obtained with a water jet. Further, a fiber structure obtained by carding with 20% by mass or more of composite staple fibers can be obtained by entanglement with a needle punch process and then splitting by a physical method such as buffing.

  In addition, a sheet-like fiber structure can be obtained by making paper using a paper stock containing 20% by mass or more of the composite staple fiber of the present invention, and a fiber structure can be obtained by splitting and entanglement with a water jet. Further, after the sheet-like fiber structure is entangled by needle punching, it is split by a physical method such as buffing to obtain a fiber assembly. Moreover, a fiber structure can also be produced by making a paper using 20% by mass or more of a paper stock obtained by splitting composite staple fibers in advance by a physical method.

  When the composite staple fiber content of the fiber structure is less than 20% by mass, the effect of the acute edge section of the ultrathin flat fiber composed of the polymer polymer component (A) after the division is hardly exhibited. The wiping performance is not sufficient, and in the case of a sheet-like structure, the gloss due to the flat cross section hardly appears.

  Other fibers used in combination with the composite staple fiber of the present invention include synthetic fibers such as polyester fiber, nylon fiber, acrylic fiber, polyvinyl alcohol fiber, polyethylene fiber, polypropylene fiber, and vinyl chloride fiber, and pulp, silk, hemp Natural fibers such as can be selected. Two or more kinds of fibers may be used.

  In the present invention, various fiber structures including composite staple fibers can be laminated and entangled with other fiber structures such as woven fabrics and knitted fabrics. The fiber structure after entangled can be subjected to physical treatment to split the composite staple fiber.

  The present invention expresses the maximum effect when a hydroentanglement treatment, a buffing treatment, or the like is employed as a splitting treatment method for a composite staple fiber, but the polymer component (A) is polyester. In this case, it does not preclude performing the dividing process by the alkali weight reduction process.

  The fiber structure can be used for various applications. For example, the fiber structure can be used as a wiper as it is or by impregnating the fiber structure with various resins as necessary.

  Furthermore, it is possible to obtain artificial leather by processing the fiber structure by a method according to the purpose. For example, an artificial leather can be obtained by impregnating a polyurethane resin into a fiber structure obtained by splitting by a chemical treatment method such as alkali weight reduction with an aqueous sodium hydroxide solution after card treatment or needle punch treatment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these at all.

[Measurement method of fineness]
Prepare 5 sets of samples of 30 single yarns cut to 30 mm, and measure the weight of each sample (5 sets) (perform twice).
Fineness (dtex) = weight (g) / (number of 30 × fiber length 30 mm) × 10000 m

[Judgment of cross-sectional shape]
The cross-sectional shape is observed and judged using a microscope.
○: The component (B) is completely covered with the component (A), and the component (B) and the component (A) other than the covering portion are substantially flat.
Δ: The component (B) and the component (A) other than the covering portion are substantially flat, but the component (B) is not completely covered by the component (A). Further, the component (A) and the component (B) are partially peeled off.
X: The component (B) and the component (A) other than the covering portion are not flat, and either component has disappeared.

[Judgment of spinnability]
Based on the following criteria, an evaluation of spinnability was carried out (evaluation of yarn breakage and wrinkle is the result of spinning for 4 hours).
○: Can be wound after spinning from the nozzle, and troubles such as yarn breakage and tacking do not occur.
Δ: Can be spun off after spinning from the nozzle, but troubles such as yarn breakage and wrinkling frequently occur.
×: Cannot be spun from the nozzle, or even if spun, it cannot be wound up and a sample cannot be collected.

[Judgment of uneven color]
As an index of the dispersibility of carbon black, it is visually determined whether there is uneven color.
○: No uneven color.
×: There is uneven color.

[Examples 1-2]
(1) Polyethylene terephthalate (“RB-865” manufactured by Kuraray Co., Ltd.) is used as the polymer component (A), and polypropylene (“Y-2005GP” manufactured by Prime Polymer Co., Ltd.) is used as the polymer component (B). 0.5% by mass of carbon black ("PESM20216-BLACK20%" manufactured by Dainichi Seika Kogyo Co., Ltd.) is added only to the polymer component (A) side, and the polymer component (A) and the polymer component are added. Spinning was carried out at a spinning ratio of 300 ° C. under the conditions where the mass ratio of (B) was 72/28 (Example 1) and 70/30 (Example 2).
(2) The results are shown in Table 1. The spinnability was good, the cross-sectional shape and color unevenness were satisfactory, and raw cottons with L values of 29 (Example 1) and 30 (Example 2) could be collected.

[Examples 3 to 5]
(1) The polymer composition and mass ratio of the high molecular weight polymer component (A) and the high molecular weight polymer component (B) are the same as those in Example 1, and the conditions for the high molecular weight polymer components (A) and (B) are as follows. The carbon black addition concentration is 0.5% by mass (Example 3), the carbon black concentrations of the polymer components (A) and (B) are both 1.0% by mass (Example 4), the polymer weight Spinning was performed under the same conditions as in Example 1 with the carbon black concentrations of the combined components (A) and (B) both set to 5.0 mass% (Example 5). As the carbon black on the polymer (B) side, “Spundye PGBLACK7280 BLACK30%” manufactured by DIC Corporation was used.
(2) The results are shown in Table 1. The spinnability was good, the cross-sectional shape and the color unevenness were satisfactory, and raw cottons having L values of 26 (Example 3), 21 (Example 4), and 15 (Example 5) could be collected.

[Example 6]
(1) The polymer composition and mass ratio of the polymer component (A) and the polymer component (B) are the same as in Example 1, and carbon black is applied only to the polymer component (B) side. 0.5% by mass was added, and spinning was performed under the same conditions as in Example 1.
(2) The results are shown in Table 1. The spinnability was good, the cross-sectional shape and color unevenness were satisfactory, and raw cotton having an L value of 32 could be collected.

[Comparative Example 1]
The polymer composition and mass ratio of the polymer component (A) and the polymer component (B) are the same as in Example 1, and the carbon black to the polymer components (A) and (B) Spinning was carried out under the same conditions as in Example 1 with both addition concentrations of 15% by mass. However, since the carbon black content was too high, yarn breakage occurred, and the raw cotton could not be collected stably.

[Comparative Example 2]
In Example 1, the mass ratio of the polymer component (A) to the polymer component (B) was 91/9, and 1% by mass of carbon black was added only to the polymer component (B) side. As a result, the mass ratio on the polypropylene side was sometimes too small, and in the cross-sectional shape of the fiber, a part of the polypropylene disappeared, resulting in a raw cotton having an L value of 36 and poor color developability.

  According to the present invention, a composite staple fiber having excellent colorability can be obtained, and a flat single yarn can be obtained by splitting the fiber, and a woven fabric, a knitted fabric, and a nonwoven fabric containing the fiber. In the case of the above, an ultrafine fiber structure having a large surface area can be obtained, and the ultrafine fiber structure can obtain an excellent effect in terms of sound absorption.

Sectional drawing which shows an example of the cross section of the staple fiber of this invention. Sectional drawing of the flat extra fine fiber which consists of a high polymer component (A) published by carrying out the division | segmentation process of the composite staple fiber. Sectional drawing of the flat extra fine fiber which consists of a high molecular polymer component (B) published by carrying out the division | segmentation process of the composite staple fiber.

Claims (7)

The high-molecular-weight polymer component (A) and / or high-molecular-weight polymer component (B) contain either 0.1 to 10% by mass of carbon black having an average primary particle size of 5 to 50 nm in one or both, and high A staple fiber having a bonded composite form in which a molecular polymer component (A) and a polymer component (B) are alternately arranged in the cross section of the fiber, and the following (1) to (4) Composite staple fiber that satisfies all.
(1) The polymer component (B) is completely covered with the polymer component (A), and the polymer component (A) other than the polymer component (B) and the coating portion. Is substantially flat,
(2) The long-side tip of the polymer component (B) has a circular cross-sectional shape and is located 0.05 to 1.5 μm inside from the fiber surface;
(3) The mass ratio of the polymer component (A) and the polymer component (B) is 90/10 to 10/90,
(4) In the said fiber cross section, the thickness (D) of the short side direction of a polymer component (A) and a polymer component (B) is 3 micrometers or less, respectively, and a polymer component (A) ), (B) The ratio (L / D) of the length (L) in the long side direction to the thickness (D) in the short side direction in both components is 2 or more.   The composite staple fiber according to claim 1, wherein the polymer component (A) is a polyester, and the polymer component (B) is a fiber-forming polyolefin polymer or polyamide polymer.   A fiber structure comprising 20% by mass or more of the composite staple fiber according to claim 1 or 2, wherein the interface between the polymer component (A) and the polymer component (B) of the compound staple fiber is at least A part of the polymer polymer component (A) is peeled off to form an acute edge structure with a protruding shape in the cross section at the end in the long side direction, and fibers constituting the nonwoven fabric are entangled with each other. A fiber structure.   The fiber structure according to claim 3, wherein the fiber structure is a dry nonwoven fabric or a wet nonwoven fabric.   The fiber structure according to claim 3 or 4, wherein the fiber structure is integrated with a woven fabric or a knitted fabric.   It is a wiper material, The fiber structure of any one of Claims 3-5.   The fiber structure according to any one of claims 3 to 5, which is a base fabric for artificial leather.

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