JPWO2019093272A1 - Fiber structure and its manufacturing method - Google Patents

Abstract

The present invention is a fiber structure containing a coiled crimp fiber (a) and a non-coiled crimp fiber (b), and the fiber structure is an entanglement composed of the coiled crimp fiber (a). The distance between at least one entangled portion (B) in the flow direction of the fiber structure having the entangled portion (A) and the entangled portion (B) composed of the non-coiled crimped fiber (b). However, the present invention relates to a fiber structure in which the apparent average fiber length of the coiled crimped fiber (a) is less than the apparent average fiber length.

Description

The present invention relates to a fiber structure that can be suitably used as a bandage or the like, and a method for producing the same.

Conventionally, in fields such as medical treatment and sports, tapes such as various bandages and supporters have been used for the purpose of appropriately compressing, fixing, and protecting application sites such as limbs and affected areas. These tapes are required to have elasticity, followability, sweat absorption, breathability, and the like, and to be fixed by self-adhesion or adhesion.

Generally, a soft component such as rubber-based or acrylic-based latex is applied to the bandage surface for the purpose of satisfying elasticity and fixing property (Patent Documents 1 to 5). However, these soft components also include the possibility of causing stuffiness due to irritation to the skin and blocking of air permeability, and further causing allergies, which is not preferable from the viewpoint of safety.

A medical material using low-protein natural rubber latex as an adhesive (Patent Document 6) and a self-adhesive bandage using a specific acrylic polymer as an adhesive for the purpose of reducing skin irritation (Patent Document 7). Has been proposed. However, the use of adhesives in these medical materials and self-adhesive bandages has not changed and has not been a fundamental solution.

As a non-woven fabric that can be self-adhesive without applying an adhesive, a non-woven fabric that has elasticity and can be easily cut by hand using a composite fiber that has potential heat crimpability (Patent Document 8), or repeatedly. A high-stress type stretchable nonwoven fabric that can be used (Patent Document 9) has been proposed.

Tokukousho 48-000309 Gazette Japanese Unexamined Patent Publication No. 63-068163 Japanese Unexamined Patent Publication No. 63-260553 Japanese Unexamined Patent Publication No. 01-19935 Japanese Unexamined Patent Publication No. 11-0898774 Special Table 2003-514105 Japanese Unexamined Patent Publication No. 2005-095381 International Publication No. 2008/015972 International Publication No. 2016/031818

However, it was found that the non-woven fabric described in Patent Document 8 is easily torn when strongly wound. Further, since the non-woven fabric described in Patent Document 9 has high stress, it has a characteristic that it is hard to be torn even when it is strongly wound, but it tends to have high stress even when it is stretched low, and the initial lineability is improved. It turned out that there was room.

Therefore, the present invention has a very low stress at the time of low elongation, and although it is excellent in initial lineability, it has a very high stress at the time of high elongation, and can be strongly wound, and is easily stretched but hard to tear. The purpose is to provide a structure.

The present inventors have found that the non-woven fabric described in Patent Document 8 has low strength and is easy to stretch because the expressed crimps are entangled with each other, but it may break. Further, the non-woven fabric obtained by entwining by the span lace method or the needle punch method described in Patent Document 9 and then treating with high-speed steam is entangled with the sheet itself, and the expressed crimp is not utilized, and the non-woven fabric is shrinkable. It turned out that it was difficult to obtain.

As a result of diligent studies to achieve the above object, the present inventors are composed of an entangled portion (A) composed of coiled crimp fibers (a) and non-coiled crimp fibers (b). It has two or more entangled portions (B), and the distance between at least one entangled portions (B) in the flow direction of the fiber structure is the apparent average fiber length of the coiled crimped fiber (a). It has been found that the above object can be achieved if the fiber structure is less than.

That is, the present invention includes the following.
[1] A fiber structure containing a coiled crimp fiber (a) and a non-coiled crimp fiber (b), and the fiber structure is entangled composed of the coiled crimp fiber (a). It has two or more entangled portions (B) composed of a portion (A) and a non-coiled crimped fiber (b), and is between at least one entangled portion (B) in the flow direction of the fiber structure. The fiber structure is less than the apparent average fiber length of the coiled crimped fiber (a).
[2] The fiber structure according to [1], wherein the ratio of the area of the entangled portion (A) to the surface area of the fiber structure on the surface of the fiber structure is 20 to 85%.
[3] the ratio between the thickness _{(T B)} of the entangled thickness of the portion _{(A) (T} A) and the entangled portion (B) _{is T A / T B = 1.1~10,} [ The fiber structure according to 1] or [2].
[4] The method according to any one of [1] to [3], wherein the 50% elongation stress is 15 N / 5 cm or less and the 80% elongation stress is 20 N / 5 cm or more in the flow direction of the fiber structure. Fiber structure.
[5] Ratio of 50% elongation stress to 80% elongation stress in the flow direction of the fiber structure 80% elongation stress / 50% elongation stress is 2.7 or more, [1] to [4] ] The fiber structure according to any one of.
[6] The fiber according to any one of [1] to [5], wherein the coiled crimp fiber (a) is composed of a composite fiber in which a plurality of resins having different heat shrinkage rates form a phase structure. Structure.
[7] The fiber structure according to any one of [1] to [6], which has a basis weight of 50 to 200 g / m ² .
[8] A bandage containing the fibrous structure according to any one of [1] to [7].
[9] The method for producing a fiber structure according to any one of [1] to [8].
1) The process of converting fibers to the web,
2) includes a step of forming an entangled portion (B) by entwining a part of the web by spraying or spraying water, and 3) a step of heating the web with high temperature steam to form an entangled portion (A). ,Production method.

Since the fiber structure of the present invention has excellent initial lineability and can be tightly wound, it can be suitably used for bandages and the like.

FIG. 1 is a schematic view showing an arrangement pattern of entangled portions (B) in the flow direction of the fiber structure obtained in Example 1. It is a schematic diagram which shows the method of preparing the sample for measuring the curved surface slip stress. It is sectional drawing which shows the sample for measuring the curved surface slip stress. It is a schematic diagram which shows the measuring method of a curved surface slip stress.

[Fiber structure]
The fiber structure of the present invention (hereinafter, also simply referred to as “fiber structure”) is composed of an entangled portion (A) composed of coiled crimped fibers (a) and a non-coiled crimped fiber (b). It has an entangled portion (B) to be formed. In the entangled portion (A), the fiber structure of the present invention has a structure in which the coiled crimp fibers (a) are entangled with each other at their crimped coil portions to be restrained or hooked. On the other hand, in the entangled portion (B), the entangled portion is formed by compacting the fibers without the crimping of the non-coiled crimped fibers (b). The coiled crimped fiber (a) and the non-coiled crimped fiber (b) are preferably oriented in the flow direction of the fiber structure, and the coiled crimped fiber (a) is along the orientation axis. It is preferable that the fibers are crimped into a coil.

The flow direction of the fiber structure is the flow direction (MD direction) of the fiber structure in the manufacturing process, and when the fiber structure has a length direction and a width direction such as a bandage, the length direction. Is preferable. In this case, the fibrous structure, which is a bandage, can be wrapped around the application site while being stretched along its length direction. When the fiber structure has a length direction and a width direction, the CD direction, which is a direction orthogonal to the MD direction, is preferably the width direction.

In the fiber structure of the present invention, since the fibers are relatively weakly entangled at the entangled portion (A), the stress is very low at the time of low elongation and the initial lineability is excellent. Further, since the fibers are firmly entangled with each other at the entangled portion (B), the stress becomes extremely high at the time of high elongation, and the fibers can be wound.

In the fiber structure of the present invention, the distance between at least one entangled portion (B) in the flow direction of the fiber structure (hereinafter, also simply referred to as “distance between entangled portions (B)”) is coiled. It is less than the apparent average fiber length of the crimped fiber (a). The distance between the entangled portions (B) in the flow direction of the fiber structure is the closest to any one entangled portion (B) of the fiber structure and the entangled portion (B) in the flow direction. The shortest distance in the flow direction with another entangled portion (B) that exists. When the distance between the entangled portions (B) is equal to or larger than the apparent average fiber length of the coiled crimped fibers (a), the space between the entangled portions (B) is the crimped coil portion of the coiled crimped fibers (a). Only the entangled coil portion is entangled, and at the time of high extension, the entangled coil portion expands and finally unravels, so that the portion tends to be easily cut. On the other hand, if the distance between the entangled portions (B) is less than the apparent average fiber length of the coiled crimped fibers (a), at least one end of the coiled crimped fibers (a) is entangled in the entangled portion (B). Therefore, the coiled crimped fibers (a) are not unraveled even at the time of high elongation, and tend to easily exert high stress at the time of high elongation. From the above viewpoint, it is preferable that at least a part of the coiled crimp fiber (a) is entangled at both ends thereof at the entangled portion (B).

The two entangled portions (B) constituting the distance between the entangled portions (B) are arranged so that at least a part of them can be entangled with the coiled crimp fibers (a) oriented in the flow direction. It is preferable to be done. When the entangled portion (B) is entangled with the coiled crimp fiber (a), a high stress tends to be easily obtained at the time of high elongation. The greater the number of coiled crimped fibers (a) entwined with the entangled portion (B), the more likely it is that strong entanglement between the entangled portion (B) and the coiled crimped fibers (a) will occur. .. When the fiber structure is in the form of a sheet, the entangled portion (B) may be regularly formed in the sheet surface, and the entangled portion (A) and the entangled portion (B) are in the flow direction. It may be arranged in an alternately arranged border pattern, a plane lattice pattern in which entangled portions (B) having a specific shape are regularly arranged, for example, a square lattice pattern, an oblique lattice pattern, a rectangular lattice pattern, or the like. preferable. FIG. 1 shows the distances between the entangled portions (B) 2, the entangled portions (A) 3, and the entangled portions (B) of the fiber structure 1 having the orthorhombic lattice pattern obtained in Example 1 described later. 4 is shown.

When the entangled portion (B) is arranged in a border pattern, the width (length in the flow direction) of the entangled portion (B) may be, for example, 0.5 to 30 mm, preferably 1 to 20 mm. It is preferably 2 to 10 mm, more preferably 3 to 8 mm.

When the entangled portions (B) are arranged in a plane grid pattern, the spacing in the direction perpendicular to the flow direction (the spacing in the direction perpendicular to the "distance between the entangled portions (B)") is For example, it may be 0.5 to 30 mm, preferably 1 to 20 mm, more preferably 2 to 10 mm, still more preferably 3 to 8 mm.

When the entangled portion (B) is arranged in a plane lattice pattern, the shape of the entangled portion (B) is not particularly limited, but may be, for example, an oval, an ellipse, a circle, a square, a rectangle, or the like. , Preferably oval. In the case of an oval shape, the length in the major axis direction may be, for example, 1 to 80 mm, preferably 5 to 60 mm, more preferably 10 to 40 mm, and the length in the minor axis direction is, for example, 1 to 80 mm. It is preferably 3 to 50 mm, more preferably 5 to 30 mm.

In the fiber structure, the higher the proportion of the coiled crimped fibers (a) between the entangled portions (B) is less than the apparent average fiber length, the higher the stress tends to be exhibited at the time of high elongation. Therefore, in the fiber structure, for example, 10% or more of the entangled portions (B) in the flow direction of the fiber structure are less than the apparent average fiber length of the coiled crimped fiber (a). The distance between the entangled portions (B) existing in the flow direction of the fiber structure is preferably 30% or more, more preferably 60% or more, still more preferably 90% or more, and particularly preferably 95% or more. , The distance between them is less than the apparent average fiber length of the coiled crimped fiber (a).

The apparent average fiber length of the coiled crimped fiber (a) (hereinafter, also simply referred to as “apparent average fiber length”) is the fiber length obtained by stretching the coiled crimped fiber into a straight line (actual fiber length). It is not the average value of the fiber length (apparent fiber length) in a coiled state. Therefore, the apparent average fiber length is measured shorter than the actual fiber length. The apparent average fiber length is determined by measuring the surface of the fiber structure with an electron microscope and determining any of the coiled crimped fibers (a) existing per 1 cm ^{2 on} the surface of any entangled portion (A) of the fiber structure. The apparent fiber lengths of the 100 selected fibers were measured, and the average value was calculated.

The apparent average fiber length may be, for example, 10 mm or more, preferably more than 10 mm, more preferably 11 mm or more, still more preferably 12 mm or more, and particularly preferably 13 mm or more. On the other hand, the apparent average fiber length may be, for example, 70 mm or less, preferably 55 mm or less, more preferably 40 mm or less, still more preferably 30 mm or less, and particularly preferably 21 mm or less.

The distance between the entangled portions (B) may be, for example, 2.5 mm or more, preferably 3 mm or more, and more preferably 3.5 mm or more. Further, at least one of the distances between the entangled portions (B) may be, for example, 20 mm or less, preferably less than 20 mm, more preferably 15 mm or less, and further preferably 10 mm or less. When at least one of the distances between the entangled portions (B) is between the above upper limit value and the lower limit value, the entangled portions (B) are entangled with each other by the coiled crimp fibers (a). It becomes high stress at high elongation and tends to be difficult to tear even when tightly wound.

In the present invention, the entangled portion (B) may contain a small amount of the coiled crimp fiber (a), for example, up to 3% by mass with respect to the total mass of the entangled portion (B). The entangled portion (A) may contain a small amount of the non-coiled crimped fiber (b), for example, up to 3% by mass with respect to the total mass of the entangled portion (A). Further, one fiber may have a coiled crimped portion and a non-coiled crimped portion.

In the fiber structure, the ratio of the area of the entangled portion (A) to the surface area of the fiber structure on the surface of the fiber structure may be, for example, 20 to 85%, preferably 30 to 83%. More preferably, it is 40 to 81%. The area of the entangled portion (A) is a value obtained by the measuring method described in Examples described later. When the ratio of the area of the entangled portion (A) is within the above range, the stress at the time of low elongation becomes low, and excellent lineability tends to be easily obtained.

Fibrous structure, the ratio _T A / _{T B} between the thickness _{(T B)} of the thickness of the entangled portion _{(A) (T} A) and entangled portions (B) may be, for example, 1.1 to 10 , Preferably 2-7, more preferably 3-5. If the ratio _T A / _{T B} and the thickness of the thickness _{(T A)} and entangled portions (B) of the entangled portions (A) _{(T B)} is in the above range, advantageously good balance of softness and strength Is.

Entangled thickness of the portion _{(A) (T} A) can be, for example, a 1 to 10 mm, preferably 1.5 to 7 mm, more preferably 2 to 5 mm.

The thickness of the entangled portion _{(B) (T} B) can be, for example, a 0.2 to 1 mm, preferably 0.3 to 0.9 mm, more preferably 0.4 to 0.8 mm.

The thickness of the thickness _{(T A)} and entangled portions (B) of the entangled portions (A) _{(T B)} was measured thickness according to JIS L1913 "General short fiber nonwoven fabric testing method".

The basis weight of the fiber structure is preferably 50 to 200 g / m ² , and more preferably 70 to 180 g / m ² .

When the basis weight and thickness are in the above ranges, the balance between elasticity, flexibility, texture and cushioning of the fiber structure is good. The density (bulk density) of the entangled portions (A) and (B) of the fiber structure can be a value according to the basis weight and the thickness. The density (bulk density) of the entangled portion (A) of the fiber structure may be, for example, 0.03 to 0.15 g / cm ³ , preferably 0.04 to 0.1 g / cm ³ . The density (bulk density) of the entangled portion (B) of the fiber structure can be a value according to the above-mentioned texture and thickness, for example, 0.15 to 1.5 g / cm ³ , preferably 0.2. ~ 1 g / cm ³ .

In the fiber structure, the stress at 50% elongation in the flow direction of the fiber structure may be, for example, 15 N / 5 cm or less, preferably 13 N / 5 cm or less, and more preferably 12 N / 5 cm or less. When the stress at 50% elongation in the flow direction of the fiber structure is not more than the above upper limit value, the stress becomes low at the time of low elongation and tends to be excellent in the initial lineability. The lower limit of the stress at 50% elongation in the flow direction of the fiber structure is not particularly limited, but may be, for example, 1 N / 5 cm or more.

In the fiber structure, the stress at 80% elongation in the flow direction of the fiber structure may be, for example, 20 N / 5 cm or more, preferably 25 N / 5 cm or more, and more preferably 30 N / 5 cm or more. When the stress at 80% elongation in the flow direction of the fiber structure is equal to or higher than the above value, the stress becomes high at the time of high elongation and tends to be difficult to tear even when strongly wound. The upper limit of the stress at 80% elongation in the flow direction of the fiber structure is not particularly limited, but is usually, for example, 50 N / 5 cm or less.

The fiber structure may have a ratio of 50% elongation stress to 80% elongation stress in the flow direction of the fiber structure, for example, 80% elongation stress / 50% elongation stress may be 2.7 or more. It is preferably 3.0 or more, more preferably 3.2 or more. When the ratio of the 50% elongation stress and the 80% elongation stress in the flow direction of the fiber structure is equal to or more than the above lower limit value, the stress becomes low at low elongation, and while excellent in initial lineability, at high elongation It becomes high stress and tends to be hard to tear even when it is tightly wound. The ratio of 50% elongation stress to 80% elongation stress in the flow direction of the fiber structure The ratio of 80% elongation stress / 50% elongation stress is not particularly limited, but may be, for example, 10 or less, preferably 8. Below, it is more preferably 5 or less.

The 50% elongation stress and the 80% elongation stress in the flow direction of the fiber structure mean the elongation stress immediately after the fiber structure is stretched at the elongation rates of 50% and 80%, respectively, and JIS L 1913. It can be measured by a tensile test according to the "general non-woven fabric test method". The 50% elongation stress and the 80% elongation stress in the flow direction of the fiber structure of the present invention are values obtained by using AG-IS manufactured by Shimadzu Corporation as a constant velocity elongation type tensile tester.

The fiber structure may have a recovery rate after 50% elongation in at least one direction (hereinafter, also referred to as a recovery rate after 50% elongation), for example, 70% or more, preferably 80% or more, and more preferably 90. % Or more. The upper limit of the recovery rate after 50% elongation is not particularly limited, but is usually 100% or less. When the 50% elongation recovery rate is within the above range, the followability to elongation is improved. For example, when the fiber structure is used as a bandage, the fiber structure is overlapped while sufficiently following the shape of the place of use. It is advantageous for improving self-adhesion due to friction between bodies. When the elongation recovery rate is excessively small, the fibrous structure cannot follow the movement when the used part has a complicated shape or moves during use, and the part deformed by the movement of the body. Is not restored, and the fixation of the wound fiber structure is weakened.

The at least one direction is preferably the flow direction of the fiber structure described above. When the fiber sheet has a length direction and a width direction such as a bandage, it is preferably the length direction of the fiber sheet.

The recovery rate after elongation of 50% is the residual strain (%) after the test when the load is removed immediately after the elongation rate reaches 50% in the tensile test based on JIS L 1913 "General non-woven fabric test method". When is X, the following formula:
Recovery rate after 50% elongation (%) = 100-X
Defined in.

The recovery rate after 50% elongation in a direction other than the above at least one direction of the fiber structure, for example, the CD direction, or in the width direction when the fiber structure has a length direction and a width direction like a bandage, is, for example, 70% or more. It may be (100% or less), preferably 80% or more.

The fiber structure preferably exhibits self-adhesiveness. As used herein, the term "self-adhesiveness" refers to the property that fibers on the surface of a fiber structure can be hooked or fixed by being engaged or in close contact with each other by superposition (contact) of the fibers. Having self-adhesiveness is advantageous when the fibrous structure is a bandage or the like. For example, when the fiber structure is a bandage, the wound fiber sheets are stretched and pressed against each other by the action of wrapping the bandage around the application site and then superimposing the end portion on the surface of the bandage underneath. The fiber structures are joined and fixed to each other to exhibit self-adhesiveness.

Since the fiber structure has self-adhesiveness, a stopper for forming a layer made of a self-adhesive such as an elastomer or an adhesive on the surface of the fiber structure or fixing the tip after winding is prepared separately. You don't have to do it. The fiber structure is preferably composed only of a non-elastomer material, and more specifically, it is preferably composed only of fibers. For example, in Japanese Patent Application Laid-Open No. 2005-095381 (Patent Document 7, Claim 1, Paragraphs [0004] to [0006]), an acrylic polymer or latex is attached as an adhesive to at least one surface of a bandage base material. Is described. However, forming such a layer made of an elastomer on the surface of the fiber sheet may cause problems such as blood circulation inhibition and pain when wrapped around the application site for a long time. In addition, the layer made of elastomer may induce skin irritation and allergies when wrapped around the application site.

The self-adhesiveness of the fiber structure can be evaluated by the curved surface sliding stress. The curved surface slip stress of the fiber structure may be, for example, 1N / 50 mm or more, preferably 3N / 50 mm or more, and the curved surface sliding stress is preferably larger than the breaking strength. Further, when desired, the curved surface slip stress is preferably 30 N / 50 mm or less, more preferably 25 N / 50 mm or less, because it is relatively easy to unwind the wound fiber structure. The curved surface slip stress can be measured using a tensile tester according to the method described in the section of Examples (FIGS. 2 to 4).

The fiber structure is preferably hand-cut. As used herein, the term "hand-cutting property" refers to a property that can be broken (cut) by pulling by hand. The hand-cutting property of the fiber structure can be evaluated by the breaking strength. When the fiber structure is in the form of a sheet, the breaking strength in at least one direction in the plane is preferably 5 to 100 N / 50 mm, more preferably 8 to 60 N / 50 mm, still more preferably 10 to 10 from the viewpoint of hand cutting property. It is 40 N / 50 mm. When the breaking strength is in the above range, it is possible to impart good hand-cutting property that can be broken (cut) relatively easily by hand. If the breaking strength is too large, the hand-cutting property is lowered, and it tends to be difficult to cut the fiber structure with one hand, for example. Further, if the breaking strength is too small, the strength of the fiber structure is insufficient and the fiber structure is easily broken, and the durability and handleability tend to decrease. The breaking strength can be measured by a tensile test according to JIS L 1913 "General Nonwoven Fabric Test Method".

At least one direction in the sheet surface is a tensile direction when the fiber structure is cut by hand, and is preferably a flow direction of the fiber structure. When the fiber structure has a length direction and a width direction such as a bandage, it is preferably the length direction of the fiber structure. That is, when the fibrous structure is used as a bandage, the flow direction is the tensile direction because it is usual to wind the bandage around the application site while extending along its length direction and then break it in the length direction. It is preferable that the length direction is.

The breaking strength in a direction other than at least one direction in the sheet surface, for example, the CD direction, or in the width direction when the fiber sheet has a length direction and a width direction like a bandage, is, for example, 0.1 to 300 N / 50 mm. It may be, preferably 0.5 to 100 N / 50 mm, and more preferably 1 to 20 N / 50 mm.

From the viewpoint of hand-cutting property, the fiber structure is preferably composed of only a non-elastomer material, and more specifically, it is preferably composed of only fibers. When a layer made of an elastomer or the like is formed on the surface of the fiber structure, the hand-cutting property may be lowered.

The fiber structure may have a breaking elongation in at least one direction in the sheet surface, for example, 50% or more, preferably 60% or more, and more preferably 80% or more. Having the elongation at break in the above range is advantageous in increasing the elasticity of the fiber structure. Further, when the fiber structure is used as a bandage, it is possible to improve the followability when the fiber structure is applied to a portion having a large movement such as a joint. The elongation at break in at least one direction in the sheet surface is usually 300% or less, preferably 250% or less. The elongation at break can also be measured by a tensile test according to JIS L 1913 "General Nonwoven Fabric Test Method".

At least one direction in the sheet surface is preferably the first direction. This first direction can be the MD direction, and when the fiber structure has a length direction and a width direction such as a bandage, it is preferably the length direction of the fiber structure.

The elongation at break in a direction other than at least one direction in the sheet surface, for example, the CD direction, or in the width direction when the fiber structure has a length direction and a width direction like a bandage, is, for example, 10 to 500%. It is preferably 100 to 350%.

The coiled crimped fiber (a) can be composed of a composite fiber having a potential heat crimpability (hereinafter, also simply referred to as “composite fiber”).

A composite fiber is a composite fiber in which a plurality of resins having different coefficients of thermal expansion or coefficient of thermal expansion form a phase structure, and is asymmetrical or layered, which causes crimping by heating due to the difference in coefficient of thermal expansion or coefficient of thermal expansion. It is a fiber having a (so-called bimetal) structure. Multiple resins usually differ in softening point or melting point. The plurality of resins include, for example, polyolefin-based resins (for example, low-density, medium-density or high-density polyethylene, poly-C _2-4 olefin-based resins such as polypropylene), acrylic resins (for example, acrylonitrile-vinyl chloride copolymer, etc.). Acrylonitrile-based resins having acrylonitrile units, polyvinyl acetal-based resins (eg, polyvinyl acetal resins, etc.), polyvinyl chloride-based resins (eg, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, vinyl chloride-acrylonitrile copolymers, etc.) ), Polyvinylidene chloride resin (for example, vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-vinyl acetate copolymer, etc.), styrene resin (for example, heat-resistant polystyrene), polyester resin (for example, polyethylene terephthalate resin, polytri). Polyamide terephthalate resin, polybutylene terephthalate resin, poly C _2-4 alkylene allylate resin such as polyethylene naphthalate resin, polyamide resin (for example, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, polyamide 612, etc.) Aromatic polyamide resins such as aliphatic polyamide resins, semi-aromatic polyamide resins, polyphenylene isophthalamides, polyhexamethylene terephthalamides, polyp-phenylene terephthalamides, etc.), polycarbonate resins (eg, bisphenol A type polycarbonate, etc.) ), Polyparaphenylene benzobisoxazole resin, polyphenylene sulfide resin, polyurethane resin, cellulose resin (for example, cellulose ester) and other thermoplastic resins may be selected. In addition, each of these thermoplastics may contain other copolymerizable units.

Among them, non-wet heat adhesive resins (or heat-resistant hydrophobic resins or non-aqueous resins) having a softening point or melting point of 100 ° C. or higher, from the viewpoint of melting or softening even when heat-treated with high-temperature steam so that the fibers do not fuse. For example, polypropylene-based resins, polyester-based resins, polyamide-based resins and the like are preferable, and aromatic polyester-based resins and polyamide-based resins are more preferable from the viewpoint of excellent balance of heat resistance and fiber-forming property. In the present invention, the resin exposed on the surface of the composite fiber is preferably a non-wet heat adhesive fiber so that each fiber constituting the fiber structure is not fused even if it is treated with high temperature steam.

The plurality of resins constituting the composite fiber may have different heat shrinkage rates, and may be a combination of resins of the same type or a combination of different resins.

In the present invention, from the viewpoint of adhesion, it is preferable that the resin is composed of a combination of resins of the same type. In the case of a combination of resins of the same type, a combination of a component (A) forming a homopolymer and a component (B) forming a modified polymer (copolymer) is usually used. That is, the crystallinity is lower than that of the homopolymer by modifying the homopolymer by copolymerizing, for example, a copolymerizable monomer that lowers the crystallinity, the melting point, the softening point, and the like. Alternatively, it may be amorphous and have a lower melting point or softening point than the copolymer. In this way, the heat shrinkage rate may be different by changing the crystallinity, melting point or softening point. The difference in melting point or softening point may be, for example, 5 to 150 ° C., preferably 50 to 130 ° C., and more preferably about 70 to 120 ° C. The proportion of the copolymerizable monomer used for the modification may be, for example, 1 to 50 mol%, preferably 2 to 40 mol%, and more preferably 3 to 30 mol% with respect to all the monomers. In particular, it is about 5 to 20 mol%). The composite ratio (mass ratio) of the component forming the homopolymer and the component forming the modified polymer can be selected according to the structure of the fiber, but the homopolymer component (A) / modified polymer component (B) is For example, it may be 90/10 to 10/90, preferably 70/30 to 30/70, and more preferably about 60/40 to 40/60.

From the viewpoint of facilitating the production of latent crimpable composite fibers, the composite fibers are a combination of aromatic polyester-based resins, particularly a combination of a polyalkylene allylate-based resin (a) and a modified polyalkylene allylate-based resin (b). It may be. The polyalkylene allylate resin (a) contains an aromatic dicarboxylic acid (terephthalic acid, a symmetric aromatic dicarboxylic acid such as naphthalene-2,6-dicarboxylic acid, etc.) and an alkanediol component (C _2- such as ethylene glycol and butylene glycol). _It may be a homopolymer with ( ₆ alkanediol, etc.). Specifically, a poly C _2-4 alkylene terephthalate resin such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) is used, and a general PET having an intrinsic viscosity of about 0.6 to 0.7 is usually used. PET used for fibers is used.

On the other hand, in the modified polyalkylene allylate-based resin (b), a copolymerization component that lowers the melting point or softening point and the degree of crystallization of the polyalkylene allylate-based resin (a), for example, an asymmetric aromatic dicarboxylic acid or an aliphatic ring group. A dicarboxylic acid component such as a dicarboxylic acid or an aliphatic dicarboxylic acid, an alkanediol component having a longer chain length than the alkanediol of the polyalkylene allylate resin (a), and / or an ether bond-containing diol component can be used.

These copolymerization components can be used alone or in combination of two or more. Among these components, the dicarboxylic acid components include asymmetric aromatic dicarboxylic acids (isophthalic acid, phthalic acid, 5-sodium sulfoisophthalic acid, etc.) and aliphatic dicarboxylic acids (C _6-12 aliphatic dicarboxylic acids such as adipic acid). ) Etc. are widely used, and as diol components, alcandiol (1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc., C- _3-6 alkanediol, etc.), polyoxyalkylene Glycos (diethylene glycol, triethylene glycol, polyethylene glycol, polyoxy C _2-4 alkylene glycol such as polytetramethylene glycol, etc.) and the like are widely used. Of these, asymmetric aromatic dicarboxylic acids such as isophthalic acid and polyoxy C _2-4 alkylene glycols such as diethylene glycol are preferable. Further, the modified polyalkylene allylate resin (b) may be an elastomer having C _2-4 alkylene arylate (ethylene terephthalate, butylene terephthalate, etc.) as a hard segment and (poly) oxyalkylene glycol or the like as a soft segment. ..

In the modified polyalkylene allylate resin (b), the ratio of the dicarboxylic acid component (for example, isophthalic acid) for lowering the melting point or the softening point as the dicarboxylic acid component is, for example, 1 with respect to the total amount of the dicarboxylic acid component. It may be about 50 mol%, preferably 5 to 50 mol%, and more preferably about 15 to 40 mol%. As the diol component, the ratio of the diol component (for example, diethylene glycol) for lowering the melting point or the softening point may be, for example, 30 mol% or less, preferably 10 mol% or less (for example, diethylene glycol) with respect to the total amount of the diol component. For example, about 0.1 to 10 mol%). If the proportion of the copolymerization component is too low, sufficient coiled crimps will not be developed, and the morphological stability and elasticity of the fiber structure after the crimps will be deteriorated. On the other hand, if the proportion of the copolymerization component is too high, the performance of developing coiled crimps will be high, but it will be difficult to spin stably.

The modified polyalkylene allylate resin (b) contains polyvalent carboxylic acid components such as trimellitic acid and pyromellitic acid, and polyol components such as glycerin, trimethylolpropane, trimethylolethane, and pentaerythritol, as required. It may be contained as a monomer component.

The cross-sectional shape of the composite fiber (the cross-sectional shape perpendicular to the length direction of the fiber) is a general solid cross-sectional shape such as a round cross section or an irregular cross section [flat, elliptical, polygonal, 3 to 14 leaf-shaped, It is not limited to T-shaped, H-shaped, V-shaped, dogbone (I-shaped), etc.] and may have a hollow cross section, but usually has a round cross section.

The cross-sectional structure of the composite fiber includes a phase structure formed of a plurality of resins, for example, core sheath type, sea island type, blend type, parallel type (side-by-side type or multi-layer bonding type), and radial type (radial bonding type). ), Hollow radiation type, block type, random composite type and other structures can be mentioned. Among these cross-sectional structures, from the viewpoint of facilitating spontaneous crimping by heating, a structure in which phase portions are adjacent to each other (so-called bimetal structure) or a structure in which the phase structure is asymmetric, for example, an eccentric core sheath type. A parallel structure is preferred.

When the composite fiber has a core-sheath type structure such as an eccentric core-sheath type, the core part has a heat shrinkage difference from the non-moisturizing adhesive resin of the sheath part located on the surface and can be crimped. Consists of moist thermosetting resins (eg ethylene-vinyl alcohol copolymers and vinyl alcohol polymers such as polyvinyl alcohol) and thermoplastic resins with low melting points or softening points (eg polystyrene and low density polyethylene) It may have been.

The average fineness of the composite fiber may be, for example, 1 to 5 dtex, preferably 1.3 to 4 dtex, and more preferably 1.5 to 3 dtex. If the fineness is too fine, it is difficult to manufacture the fiber itself and it is difficult to secure the fiber strength. In addition, in the step of developing crimp, it becomes difficult to develop a beautiful coiled crimp. On the other hand, if the fineness is too thick, the fibers become rigid and it becomes difficult to develop sufficient crimping.

The average fiber length (actual fiber length) of the composite fiber may be, for example, 20 to 70 mm, preferably 25 to 65 mm, and more preferably 40 to 60 mm. If the fiber length is too short, it becomes difficult to form a fiber web, and in the step of developing crimping, the fibers are insufficiently entangled with each other, and it becomes difficult to secure strength and elasticity. Further, if the fiber length is too long, not only is it difficult to form a fiber web having a uniform basis weight, but also many fibers are entangled with each other at the time of forming the web, and they interfere with each other when the crimps are developed. Therefore, it becomes difficult to develop elasticity. Further, in the present invention, when the fiber length is in the above range, a part of the crimped fiber on the surface of the fiber structure is appropriately exposed on the surface of the fiber structure, so that the self-adhesiveness of the fiber structure can be improved.

When the composite fiber is subjected to heat treatment, crimping is manifested (explicit), and the composite fiber becomes a fiber having a substantially coil-shaped (spiral or spiral spring-like) three-dimensional crimping.

The number of crimps (mechanical crimps) before heating may be, for example, 0 to 30 pieces / 25 mm, preferably 1 to 25 pieces / 25 mm, and more preferably 5 to 20 pieces / 25 mm. The number of crimps after heating may be, for example, 20 to 120 pieces / 25 mm, preferably 25 to 120 pieces / 25 mm.

As described above, the coiled crimp fiber (a) has a substantially coiled crimp. The average radius of curvature of the circle formed by the coil of the crimped fiber can be selected from the range of, for example, about 10 to 250 μm, for example, 20 to 200 μm (for example, 50 to 200 μm), preferably 50 to 160 μm (for example, for example). 60 to 150 μm), more preferably about 70 to 130 μm. Here, the average radius of curvature is an index showing the average size of the circle formed by the coil of the crimped fiber, and when this value is large, the formed coil has a loose shape, in other words. It means that it has a shape with a small number of crimps. Further, when the number of crimps is small, the number of entanglements between the fibers is also small, which tends to be disadvantageous for exhibiting sufficient expansion / contraction performance. On the contrary, when coiled crimps having an average radius of curvature of too small are developed, the fibers are not sufficiently entangled with each other, which makes it difficult to secure the web strength and also causes such crimps. The production of latent crimped fibers also tends to be very difficult.

In the coiled crimp fiber (a), the average pitch of the coils is preferably 0.03 to 0.5 mm, more preferably 0.03 to 0.3 mm, still more preferably 0.05 to 0.2 mm.

The non-coiled crimp fiber (b) may be composed of the composite fiber used for the coiled crimp fiber (a) described above, or may be composed of fibers other than the composite fiber (non-composite fiber). .. When the same composite fiber is used for the coiled crimped fiber (a) and the non-coiled crimped fiber (b), it tends to be advantageous because of the simplicity of the manufacturing process. Further, in the fiber structure, other fibers (non-composite fibers) are entangled in the entangled portion (A) regardless of the types of fibers constituting the coiled crimped fibers (a) and the non-coiled crimped fibers (b). And / or in the entangled portion (B), it can be included in an amount to the extent that the object of the present invention is achieved.

Non-composite fibers include, for example, fibers composed of the above-mentioned non-wet heat adhesive resin or moist heat adhesive resin, cellulosic fibers [for example, natural fibers (cotton, wool, silk, linen, etc.), semi-synthetic fibers. (Acetate fibers such as triacetate fibers), regenerated fibers (rayon, polynosic, cupra, lyocell (for example, registered trademark name: "Tencel", etc.), etc.), etc.] and the like. The average fineness and average fiber length of non-composite fibers are similar to those of composite fibers. These non-composite fibers can be used alone or in combination of two or more. Among these non-composite fibers, regenerated fibers such as rayon, semi-synthetic fibers such as acetate, polyolefin fibers such as polypropylene fibers and polyethylene fibers, polyester fibers, polyamide fibers and the like are preferable. In particular, from the viewpoint of blendability and the like, fibers of the same type as the composite fibers may be used. For example, when the composite fibers are polyester fibers, the non-composite fibers may also be polyester fibers.

When the fiber structure contains composite fibers and non-composite fibers in the entangled portion (A) and / or the entangled portion (B), the ratio (mass ratio) of the composite fibers to the non-composite fibers is, for example, the composite fibers. / Non-composite fiber = 80/20 to 100/0 (for example, 80/20 to 99/1), preferably 90/10 to 100/0, and more preferably about 95/5 to 100/0. is there. By blending non-composite fibers, the strength of the fiber structure can be adjusted. However, if the proportion of the composite fiber (latent crimp fiber) is too small, the non-composite fiber becomes a resistance to the contraction when the crimped fiber expands and contracts after the onset of crimping, especially when the crimped fiber contracts after the expansion and contraction. It tends to be difficult to secure stress.

Fiber structures (fiber webs) are further formulated with conventional additives such as stabilizers (heat stabilizers such as copper compounds, UV absorbers, light stabilizers, antioxidants, etc.), antibacterial agents, deodorants, etc. It may contain a fragrance, a colorant (dye pigment, etc.), a filler, an antistatic agent, a flame retardant, a plasticizer, a lubricant, a crystallization rate retarder, and the like. These additives can be used alone or in combination of two or more. These additives may be supported on the fiber surface or may be contained in the fiber.
[Manufacturing method of fiber structure]
The method for producing a fiber structure of the present invention is as follows: 1) a step of web-forming fibers (hereinafter, also referred to as a web-forming step), and 2) an entangled portion (B) by entwining a part of the web by spraying or spraying water. ) (Hereinafter referred to as entanglement step 1), and 3) a step of heating the web with high-temperature steam to form an entangled portion (A) (hereinafter also referred to as entanglement step 2).

In the web forming process, conventional methods such as a direct method such as a spunbond method and a melt blow method, a card method using melt blow fibers and staple fibers, and a dry method such as an air array method are used as a method for forming a web. it can. Among these methods, the card method using melt blow fibers and staple fibers, particularly the card method using staple fibers is widely used. Examples of the web obtained by using the staple fiber include a random web, a semi-random web, a parallel web, and a cross wrap web.

Next, in the entanglement step 1, a part of the obtained fiber web is entangled by spraying or spraying water to form an entangled portion (B). The water to be sprayed or sprayed may be sprayed from one side of the fiber web or from both sides, but it is preferable to spray from both sides from the viewpoint of efficiently performing strong entanglement. The portion sprayed with water becomes the entangled portion (B), and the portion not sprayed with water becomes the entangled portion (A) by the subsequent entanglement step 2.

Examples of the method of forming the entangled portion (B) include a plate-like object (perforated plate, slit plate, etc.) or a drum (perforated drum, slit drum) having a regular spray area or spray pattern formed by a plurality of holes. A method of injecting water with a spray nozzle or the like via a spray nozzle or the like, a method of forming an entangled portion (B) by switching the injection of water from the spray nozzle on and off, and a method of combining these. .. These methods include a method of continuously or periodically moving the spray nozzle according to the shape and size of the fiber web, the shape and arrangement pattern of the entangled portion (B) to be formed, an endless conveyor of the fiber web, and the like. A method of continuously or periodically transferring the fibers by the belt conveyor of the above and a method of combining these can be appropriately selected and performed. For example, the entangled portion (B) can be continuously formed by installing the spray nozzle in the above-mentioned drum, rotating the drum while injecting water, and transferring the fiber web. The material constituting the plate-shaped object and the drum may be, for example, metal, plastic, wood, or the like.

When the entangled portion (A) and the entangled portion (B) form a border-like pattern in which the entangled portion (A) and the entangled portion (B) are alternately arranged with respect to the flow direction, the entangled portion (B) is specified in a direction perpendicular to the flow direction, for example. It can be formed by injecting water from a spray nozzle onto the fiber web through a plate or drum having slits in width. The slit width may be, for example, 0.5 to 30 mm, preferably 1 to 20 mm, more preferably 2 to 10 mm, and further preferably 3 to 8 mm. The pitch of the slits is, for example, 2.5 mm or more, preferably 3 mm or more, and more preferably 3.5 mm or more. On the other hand, the pitch of the slits may be, for example, 20 mm or less, preferably less than 20 mm, more preferably 15 mm or less, still more preferably 10 mm or less.

When forming the border-shaped pattern, the entangled portion (B) sprays water by switching on and off from spray nozzles arranged linearly with respect to the flow direction while continuously moving the fiber web, for example. It can also be formed by.

When the entangled portions (B) having a specific shape form a plane lattice pattern in which the entangled portions (B) are regularly arranged, the entangled portions (B) are, for example, a plate-like object or a drum in which a plurality of holes are regularly formed. It can be formed by spraying water from the spray nozzle to the fiber web via.

The shape of the hole is not particularly limited, but may be, for example, oval, elliptical, circular, square, rectangular, or the like, and is preferably oval. In the case of an oval shape, the length in the major axis direction is, for example, 1 to 80 mm, preferably 5 to 60 mm, more preferably 10 to 40 mm, and the length in the minor axis direction is, for example, 1 to 80 mm, preferably 3 to 3. It is 50 mm, more preferably 5 to 30 mm. The plurality of holes can be arranged in a plane lattice pattern, for example, a square lattice pattern, an orthorhombic lattice pattern, a rectangular lattice pattern, or the like. The hole pitch may be, for example, 2.5 mm or more, preferably 3 mm or more, and more preferably 3.5 mm or more. On the other hand, the hole pitch may be, for example, 20 mm or less, preferably less than 20 mm, more preferably 15 mm or less, still more preferably 10 mm or less.

The water ejection pressure may be, for example, 4 MPa or more, preferably 8 MPa or more, more preferably 10 MPa or more, still more preferably 15 MPa or more, and particularly preferably more than 15 MPa. When the water ejection pressure is equal to or higher than the above lower limit value, the fibers are in a compacted state, and even if a steam jet is applied in the later entanglement step 2, the fibers are fixed and move. However, since coil-shaped crimping is unlikely to occur, the entangled portion (B) tends to be easily formed. On the other hand, the upper limit of the water ejection pressure may be, for example, 20 MPa or less.

The temperature of water is preferably 5 to 50 ° C, more preferably 10 to 40 ° C, and even more preferably 15 to 35 ° C (room temperature).

As a method of spraying or spraying water, a method of spraying water using a nozzle or the like having a regular spray area or a spray pattern is preferable from the viewpoint of convenience and the like. Specifically, water can be sprayed on the fiber web transferred by a belt conveyor such as an endless conveyor while being placed on the conveyor belt. The conveyor belt may be water-permeable, or water may be sprayed onto the fiber web by passing the water-permeable conveyor belt from the back side of the fiber web. When water is also sprayed from the back side of the fiber web, it is preferable to spray water onto the fiber web via a plate or a drum having a spray area or a spray pattern on the back side of the fiber web. The fiber web may be wetted in advance with a small amount of water in order to suppress the scattering of the fibers due to the injection of water. When transporting by a conveyor, the transport speed may be, for example, 5 to 40 m / min, preferably 10 to 20 m / min.

The nozzle for spraying or spraying water uses a plate or die in which predetermined orifices are continuously arranged in the width direction according to the pattern of the entangled portion (B) to be formed, and the fiber web to which the nozzle is supplied. The orifices may be arranged so as to line up in the width direction of. The orifice row may be one or more rows, and a plurality of rows may be arranged in parallel. Further, a plurality of nozzle dies having one row of orifice rows may be installed in parallel. The nozzle pitch may be, for example, 1.0 to 2.5 mm. The nozzle diameter may be, for example, 0.2 to 0.5 mm.

In the entanglement step 2, the fiber web is heated by high-temperature steam, and the composite fiber of the portion not sprayed with water in the above-mentioned entanglement step is crimped into a coil shape to form the entangled portion (A). become. In the method of treating with hot steam, the fiber webs are exposed to high temperature or superheated steam (high pressure steam) flow, which causes coiled crimps in the composite fibers (latent crimped fibers). Since the fiber web has breathability, even if the treatment is performed from one direction, high-temperature water vapor permeates into the inside, and substantially uniform crimping occurs in the thickness direction, and the fibers are uniformly entangled with each other. .. The temperature of the high-temperature steam may be, for example, 50 to 150 ° C, preferably 40 to 130 ° C, and more preferably 60 to 120 ° C.

In the fiber web entanglement step 1, the composite fiber in the portion not sprayed with water shrinks at the same time as the high temperature steam treatment. Therefore, it is desirable that the supplied fiber web is overfed according to the area shrinkage rate of the target fiber structure immediately before being exposed to high temperature water vapor. The ratio of overfeed is preferably 110 to 250% with respect to the length of the target fiber structure.

A conventional steam injection device can be used to supply steam to the fiber web. The steam injection device is preferably a device capable of spraying steam substantially uniformly over the entire width of the fiber web at a desired pressure and amount. The steam injection device may be provided only on one surface side of the fiber web, or may be further provided on the other surface side in order to steam treat the front and back surfaces of the fiber web at the same time.

Since the high-temperature steam injected from the steam injection device is an air flow, it enters the inside of the fiber web without significantly moving the fibers in the fiber web, unlike the water flow entanglement treatment and the needle punching treatment. By the action of the water vapor flow entering the fiber web, the water vapor flow efficiently covers the surface of each fiber existing in the fiber web, and enables uniform thermal crimping. Further, as compared with the dry heat treatment, since heat can be sufficiently conducted to the inside of the fiber web, the degree of crimping in the surface direction and the thickness direction becomes substantially uniform.

Similar to the water flow entanglement nozzle, the nozzle for injecting high-temperature steam also uses a plate or die in which predetermined orifices are continuously arranged in the width direction, and the orifice is provided in the width direction of the fiber web that supplies the plate or die. You can arrange them side by side. The orifice row may be one or more rows, and a plurality of rows may be arranged in parallel. Further, a plurality of nozzle dies having one row of orifice rows may be installed in parallel.

The pressure of the high temperature steam used can be selected from the range of 0.1 to 2 MPa (for example, 0.2 to 1.5 MPa). If the pressure of the water vapor is too high, the fibers forming the fiber web may move more than necessary, causing turbulence in the formation, or the fibers may be entangled more than necessary. If the pressure is too weak, the amount of heat required for fiber crimping cannot be applied to the fiber web, or water vapor cannot penetrate the fiber web, resulting in non-uniform fiber crimping in the thickness direction. It's easy to do. The temperature of the high-temperature steam can be selected from the range of 70 to 180 ° C. (for example, 80 to 150 ° C.), although it depends on the material of the fiber and the like. The treatment rate of high-temperature steam can be selected from the range of 200 m / min or less (for example, 0.1 to 100 m / min).

After the crimping of the composite fiber in the fiber web is expressed in this way, moisture may remain in the fiber structure. Therefore, a drying step of drying the fiber structure may be provided as necessary. As a drying method, a method using a drying facility such as a cylinder dryer or a tenter; a non-contact method such as far-infrared irradiation, microwave irradiation, or electron beam irradiation; a method of blowing hot air or passing through hot air, etc. Can be mentioned.

Since the fiber structure of the present invention has excellent initial lineability, can be tightly wound, does not contain an adhesive, and has self-adhesiveness, it is used in contact with the human body, for example, in the medical and sports fields. Suitable for tapes such as bandages and supporters used in. Another gist of the present invention is a bandage containing the above fibrous structure.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these examples.

The physical property values of the fiber structures obtained in Examples and Comparative Examples were measured by the following methods.
(1) Apparent average fiber length The surface of the fiber structure is measured with an electron microscope, and among the coiled crimped fibers (a) existing per 1 cm ^{2 on} the surface of an arbitrary entangled portion (A) of the fiber structure. The apparent fiber lengths of 100 arbitrarily selected fibers were measured, and the average value was calculated.
(2) Number of crimps The evaluation was made according to JIS L1015 “Chemical fiber staple test method” (8.12.1).
(3) Metsuke Measured according to JIS L1913 "General short fiber non-woven fabric test method".
Thickness _(T A) of (4) entangled portion (A) (convex height)
The thickness was measured according to JIS L1913 "General short fiber non-woven fabric test method".
The thickness of (5) entangled portion (B) _(T B) (base height)
The thickness was measured according to JIS L1913 "General short fiber non-woven fabric test method".
(6) Density of the entangled portion (A) The density was calculated from the basis weight measured in (3) and the thickness measured in (4) above.
(7) Density of the entangled portion (B) The density was calculated from the basis weight measured in (3) and the thickness measured in (5) above.
(8) Area ratio of the entangled portion (A) The area ratio of the entangled portion (A) existing per 0.5 cm ^{2 of the} fiber structure was determined as follows. The surface of the fiber structure was observed over 0.5 cm ² at a magnification of 300 using an electron microscope. For one field of view observed with an electron microscope, 1 is defined when only crimp fibers are visible, 0.5 is defined when crimp fibers and other fibers are mixed, and 0 is defined when no crimp fibers are present. The total was calculated, and the calculated total with respect to the number of observed visual fields was taken as the area ratio of the entangled portion (A).
(9) As a method of measuring the distance between the entangled portions (B), a ruler is used to measure the distance between two points at the center of the entangled portion and the farthest portion.
(10) 50% elongation recovery rate Measured in accordance with JIS L1096 "General textile test method". However, in the evaluation in the present invention, the recovery rate was uniformly set at an elongation of 50%, and after the elongation was 50%, after returning to the original position, the next operation was started without waiting time. The measurement was performed in the flow (MD) direction of the fiber structure. As a constant speed extension type tensile tester, AG-IS manufactured by Shimadzu Corporation was used.
(11) Stretch stress Measured in accordance with JIS L1096 "General textile test method". Each elongation stress at 50% and 80% elongation was measured. As a constant speed extension type tensile tester, AG-IS manufactured by Shimadzu Corporation was used.
(12) Self-adhesiveness The curved surface slip stress (N / 50 mm) was measured by the following method. If it is 1N / 50 mm or more, it is assumed to have self-adhesiveness.

First, the fiber sheet was cut into a size of 50 mm width × 600 mm length so that the MD direction was the length direction, and used as sample 5. Next, as shown in FIG. 2A, after fixing one end of the sample 5 to the winding core 7 (polypropylene resin pipe roll having an outer diameter of 30 mm × length of 150 mm) with a single-sided adhesive tape 6, this Using an alligator clip 8 (grasping width 50 mm, 0.5 mm thick rubber sheet fixed to the inside of the mouth with double-sided tape) at the other end of sample 5 is uniform with respect to the entire width of sample 5. A weight 9 of 150 g was attached so as to be weighted.

Next, in a state where the winding core 7 to which the sample 5 is fixed is lifted so that the sample 5 and the weight 9 are suspended, the winding core 7 is rotated 5 times so that the weight 9 does not shake significantly, and the sample 5 is wound up and the weight is wound. 9 was lifted (see FIG. 2B). In this state, the contact point between the columnar portion at the outermost peripheral portion of the sample 5 wound around the winding core 7 and the flat portion of the sample 5 not wound around the winding core 7 (the portion of the sample 5 wound around the winding core 7). And the boundary line with the part of the sample 5 that is vertical due to the gravity of the weight 9) as the base point 10, and slowly move the alligator clip 8 and the weight 9 so that the base point 10 does not move and shift. I removed it. Next, at a point 11 that is half a circumference (180 °) along the sample 5 wound around the winding core 7 from this base point 10, the outermost peripheral portion of the sample 5 is cut with a razor blade so as not to damage the sample in the inner layer. A cut 12 was provided (see FIG. 3).

The curved surface slip stress between the outermost layer portion in this sample 5 and the inner layer portion wound around the winding core 7 below it (inner layer) was measured. A tensile tester (“Autograph” manufactured by Shimadzu Corporation) was used for this measurement. The winding core 7 is fixed to the jig 13 installed on the fixed side chuck pedestal of the tensile tester (see FIG. 4), and the end portion of the sample 5 (the end portion to which the alligator clip 8 is attached) is attached to the load cell side chuck 14 The measured value (tensile strength) when the sample 5 came off (separated) at the cut 12 was defined as the curved surface slip stress.
<Example 1>
As the latent crimpable fiber, a polyethylene terephthalate resin [component (A)] having an intrinsic viscosity of 0.65 and a modified polyethylene terephthalate resin [component (B)] obtained by copolymerizing 20 mol% of isophthalic acid and 5 mol% of diethylene glycol are used. Constructed side-by-side composite staple fiber ["Sofit PN780" manufactured by Kuraray Co., Ltd., 1.7 dtex x 51 mm length, mechanical crimp number 29/25 mm, 130 ° C x 1 minute crimp number 29/25 mm after heat treatment ] Was prepared. Using 100% by mass of this side-by-side type composite staple fiber, a card web having a basis weight of 30 g / m ^{2 was} obtained by the card method.
(Mentification step 1)
The card web is moved on a conveyor net and passed between a perforated drum having holes (oval shape) in an oblique grid pattern at a pitch of 50 mm on the major axis, 5 mm on the minor axis, and 15 mm. A water stream was sprayed at 10 MPa toward the web and the conveyor net via the above to carry out a fiber entanglement step.

Next, the card web was transferred to the entanglement step 2 while overfeeding the web to about 200% so as not to inhibit the shrinkage in the entanglement step 2 due to the next steam.
(Mentification step 2)
Next, the card web is introduced into the steam injection device provided on the belt conveyor, and steam of 0.5 MPa and a temperature of about 160 ° C. is ejected perpendicularly to the card web from this steam injection device to perform steam treatment, and latent winding is performed. The coiled crimps of the crimped fibers were expressed and the fibers were entangled. In this steam injection device, a nozzle was installed in one of the conveyors so as to blow steam toward the card web via a conveyor belt. The hole diameter of the steam injection nozzle was 0.3 mm, and an apparatus was used in which the nozzles were arranged in a row at a pitch of 2 mm along the width direction of the conveyor. The processing speed was 8.5 m / min, and the distance between the nozzle and the conveyor belt on the suction side was 7.5 mm. Finally, it was dried with hot air at 120 ° C. for 1 minute to obtain a stretchable sheet-like fiber structure 1.

Various measurements were performed on the obtained fiber structure 1. The results are shown in Table 1. Further, FIG. 1 shows a schematic view of the arrangement pattern of the entangled portion (B) 2 in the flow direction of the obtained fiber structure 1.

<Example 2>
In the entanglement step 1, a fiber structure was produced in the same manner as in Example 1 except that the water flow was sprayed at a water pressure of 20 MPa. The evaluation results are shown in Table 1.

<Example 3>
Same as in Example 1 except that in the entanglement step 1, the drum is passed between the perforated drums having holes (oval shape) in an oblique lattice pattern at a pitch of 50 mm on the major axis and 10 mm on the minor axis and 10 mm. To prepare a fiber structure. The evaluation results are shown in Table 1.

<Example 4>
In the entanglement step 1, the fiber structure was formed in the same manner as in Example 1 except that the fiber structure was passed between the perforated drums having border-shaped holes at a pitch of 400 mm on the major axis, 5 mm on the minor axis, and 15 mm. Made. The evaluation results are shown in Table 1.

<Comparative example 1>
A fiber structure was produced in the same manner as in Example 1 except that the entanglement step 1 was not performed. The evaluation results are shown in Table 1.

<Comparative example 2>
Instead of performing the entanglement step 1, the card web is moved on the conveyor net and passed between the perforated drums having holes (circular shape) in an oblique lattice pattern with a diameter of 2 mmφ and a pitch of 2 mm. A spray-like water stream is sprayed from the inside of the fiber toward the web and the conveyor net at 0.8 MPa to carry out an uneven distribution step of periodically forming a low-density region and a high-density region of the fiber, and then this While transferring the card web to a belt conveyor equipped with a 76 mesh, 500 mm wide resin endless belt, using nozzles with 0.1 mm diameter orifices in a row at 0.6 mm intervals in the width direction of the web. A fiber structure was produced in the same manner as in Example 1 except that water was sprayed at a water pressure of 4 MPa. The evaluation results are shown in Table 1.

Compared with Comparative Example 2, the fiber structures of Examples 1 to 3 had a smaller stress during elongation by 50%, were excellent in initial lineability, and were also excellent in a recovery rate of 50% elongation. Further, the fiber structures of Examples 1 to 3 have higher stress when stretched by 80% than those of Comparative Example 1, and can be tightly wound. That is, the fiber structures of Examples 1 to 3 have a well-balanced performance required at the time of low elongation and high elongation as compared with Comparative Examples 1 and 2.

1 Fiber structure, 2 Entangled part (B), 3 Entangled part (A), 4 Distance between entangled parts (B), 5 Samples, 6 Single-sided adhesive tape, 7 cores, 8 Alligator clips, 9 weights, 10 base points, points half a circle from 11 base points, 12 cuts, 13 jigs, 14 chucks.

Claims (9)

A fiber structure including coiled crimped fibers (a) and non-coiled crimped fibers (b), wherein the fiber structure is an entangled portion (A) composed of coiled crimped fibers (a). ) And two or more entangled portions (B) composed of non-coiled crimped fibers (b), and the distance between at least one entangled portion (B) in the flow direction of the fiber structure is , A fiber structure having an apparent average fiber length of less than the apparent average fiber length of the coiled crimped fiber (a). The fiber structure according to claim 1, wherein the ratio of the area of the entangled portion (A) to the surface area of the fiber structure on the surface of the fiber structure is 20 to 85%. The ratio between the thickness _{(T B)} of the entangled thickness of the portion _{(A) (T} A) and the entangled portion (B) _is T _A / T B = 1.1~10, claim 1 or 2. The fiber structure according to 2. The fiber structure according to any one of claims 1 to 3, wherein the 50% stretch stress is 15 N / 5 cm or less and the 80% stretch stress is 20 N / 5 cm or more in the flow direction of the fiber structure. Any of claims 1 to 4, wherein the ratio of 50% elongation stress to 80% elongation stress in the flow direction of the fiber structure is 2.7 or more for 80% elongation stress / 50% elongation stress. The fibrous structure described. The fiber structure according to any one of claims 1 to 5, wherein the coiled crimp fiber (a) is composed of a composite fiber in which a plurality of resins having different thermal shrinkage rates or thermal expansion rates form a phase structure. body. The fiber structure according to any one of claims 1 to 6, which has a basis weight of 50 to 200 g / m ² . A bandage comprising the fibrous structure according to any one of claims 1-7. The method for producing a fiber structure according to any one of claims 1 to 8.
1) The process of converting fibers to the web,
2) includes a step of forming an entangled portion (B) by entwining a part of the web by spraying or spraying water, and 3) a step of heating the web with high temperature steam to form an entangled portion (A). ,Production method.