JP2801333B2 - Fiber structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a method of producing a conjugate fiber whose crimp form is reversibly changed by moisture absorption or water absorption (hereinafter collectively referred to as water absorption) and drying by a binder fiber. The present invention relates to a fibrous structure that is bonded and fixed. More specifically, since the composite fibers are bonded and fixed in a mesh shape by the binder fibers,
The present invention relates to a fibrous structure in which the bulk and area of the fibrous structure change greatly due to drying, are reversible, have good reproducibility, exhibit a soft feeling, and have good mechanical properties.

(Prior Art) Conventionally, it is well known that natural fibers such as cotton, wool, and feathers reversibly change their crimp ratios due to changes in humidity.

On the other hand, as synthetic fibers whose crimping rate is reversibly changed by a change in humidity, acrylic synthetic fibers are disclosed in JP-A-55-93860, and JP-A-57-66162 is disclosed. Japanese Patent Laid-Open No. 57-95360 discloses a polyester-based synthetic fiber, and further Japanese Patent Laid-Open No. 63-44843, Japanese Patent Publication No. 63-44844.
Discloses a polyester / nylon synthetic fiber. However, when these fibers are used as wadding for futons, pillows, etc., or as cotton in warm clothing, sleeping bags, etc., (1) the bulk change due to water absorption / drying is small (2) the morphological stability of the fibrous structure (3) Inferior in bulk recovery from repeated deformation, which has not yet been practically satisfactory. That is, since the fibers are not bonded and fixed in the fiber structure, 100% of the change in the crimped form of the composite fiber is not expressed as the change in the bulk / area of the fiber structure. When the crimped form change of the conjugate fiber is repeated, the fibers slide with each other, so that the fiber arrangement after the initial deformation and the fiber arrangement after the repeated deformation are different, and the form is changed. Since the fibers are not bonded and fixed, when an external force is repeatedly applied, the fibers are entangled to form a dango-like shape, resulting in insufficient bulk recovery. And the like. Furthermore, when worn, the packing density of the cotton was uneven, and there were practical problems such as a decrease in heat retention and shape loss.

A method is also known in which after forming a web from such synthetic fibers, a liquid adhesive such as latex is sprayed and then heat-treated. However, although the web having a small basis weight is relatively good, it is difficult to uniformly apply the liquid adhesive when the basis weight is 5 g / m ² or more. Still not resolved. In addition, since a liquid adhesive is usually used as an aqueous adhesive, there is a fatal defect that an adhesive point comes off due to washing.

On the other hand, obtaining a fibrous structure using a latently crimpable conjugate fiber and a binder fiber is disclosed in JP-B-43-920,
It is well known in Japanese Patent Publication No. 42-21318 and Japanese Patent Publication No. 1-2257. However, these fibrous structures are intended to improve the dimensional stability by preventing displacement between the fibers by the binder fibers, and to prevent the bulk from changing. Therefore, it has been completely known that, by bonding and fixing a conjugate fiber in a mesh shape with a binder fiber as in the present invention, a change in the crimped form of the conjugate fiber can be extremely effectively responded to a change in bulk and area. There was no.

(Object of the Invention) The present invention solves the drawbacks of the above-mentioned conventional fiber structure composed of a conjugate fiber which causes a change in the crimp rate due to water absorption and drying, and reduces the bulk and area change of the fiber structure due to water absorption and drying. It is an object of the present invention to provide a novel fibrous structure which is large, reversible, excellent in reproducibility of dimensions, has a soft feel and is not easily broken by an external force.

(Constitution of the Invention) The present inventors have conducted intensive studies in order to achieve the above object, and as a result, by heat-bonding and fixing a conjugate fiber that undergoes a change in crimp shape due to water absorption and drying using a binder fiber, -It has been found that a fiber structure having a large area change and excellent in reversibility and dimensional reproducibility can be obtained, and has reached the present invention.

That is, the present invention relates to a laminated or eccentrically bonded conjugate fiber (A) of 50 to 95% by weight, which reversibly changes the unwound form in accordance with the change in water absorption and drying. (B) A fibrous structure heat-bonded and fixed by 50 to 5% by weight, the structure having a basis weight of 5 g / m ² or more and a bulk of 10 cm ³
/ g or more, and a bulk change of 5% or more as measured under the following conditions of water absorption and drying.

The conjugate fiber used in the present invention is required to reversibly change the crimped form by water absorption and drying. For that purpose, one component of the conjugate fiber is more stretched after water absorption and drying than the other component. -The change in shrinkage is large, and it is necessary to use a composite form of a pasting type or an eccentric type.

In the case of the lamination type, the fiber after spinning and drawing usually takes a three-dimensional crimped form. Then, the change in the crimped form due to water absorption / drying differs depending on whether the component that undergoes greater elongation / shrinkage due to water absorption / drying is disposed outside or inside the three-dimensional crimped form. In addition, this arrangement relationship
In addition to the combination of polymer components used,
It also changes depending on the yarn forming conditions such as drawing and heat treatment.

If the component that expands when absorbing water and contracts when drying is placed outside the conjugate fiber in a three-dimensional crimped form, the number of three-dimensional crimps increases when the fiber absorbs water and decreases by drying. Conversely, if it is arranged inside, the number of three-dimensional voids decreases when water is absorbed, and increases due to drying. The change in the three-dimensional crimped form of the fiber appears as a change in the bulk of the fiber structure.

On the other hand, in the case of the eccentric type, in order to more effectively express the change of the three-dimensional crimped form, it is preferable to arrange a component having a large change in elongation and contraction due to water absorption and drying in the sheath, and the core is partially exposed. It doesn't matter.

Such an eccentric conjugate fiber has the advantage that it does not peel even when polymer components having low adhesion to each other are used, but on the other hand, the change in the crimp form due to water absorption and drying is inferior to that of the laminated type. Therefore, in the present invention, a composite fiber in which polymers having good adhesiveness to each other are laminated to form a composite fiber is more preferable because the finally obtained fiber structure has a large change in bulk.

The component (A-) constituting the conjugate fiber (A) used in the present invention, which expands by absorbing water and shrinks by drying.
Examples of m) include polyamide, water-absorbing polyester, and water-absorbing polyolefin. Among them, polyamide is more preferable because the degree of elongation due to water absorption and shrinkage due to drying is large, and the feeling of the obtained fiber itself is soft and the bulk is hardly set.

Examples of such polyamides include conventionally known fiber-forming polyamides having the following two general types, and these may be used as a mixture of two or more types, or may be copolymers. .

Polyamide having the first general type is a polymer obtained by polycondensing an aminocarboxylic acid such as 6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid or a derivative thereof, for example, ε-caprolactam, The other is a polymer obtained by polycondensing a diamine with a dibasic acid or an amide-forming derivative thereof.

Preferred examples of the diamine include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine, m-xylylenediamine, P-xylylenediamine, m-phenylenediamine, and P-diamine. -Phenylenediamine, bis (P-aminocyclohexyl) methane and piperazine, examples of suitable dibasic acids are sebacic acid, suberic acid, adipic acid, azelaic acid, undecandioic acid, glutaric acid,
Pimelic acid, tetradecandioic acid, isophthalic acid and terephthalic acid, but the amide-forming derivative can be replaced with the above diamines and / or dibasic acids.

For example, carbamates and N-formyl derivatives can be used instead of diamines, while mono and diesters, acid anhydrides, mono and diamides of acids and acid hydrides can be substituted for dibasic acids. These may be used alone or in combination of two or more. Of these polyamides, poly-ε-caproamide and polyhexamethylene adipamide are particularly useful industrially.

Elongation by water absorption and drying that constitutes the composite fiber (A)
Examples of the component (A-S) having a small change in shrinkage include polyester and polyolefin.
Polyester is particularly preferred from the viewpoint of bulkiness, bulk durability, heat resistance, web moldability, and the like. Above all, (A-
When a polyamide is used as the component (m), it is preferable that 5-sodium sulfoisophthalic acid is copolymerized in an amount of 2.0 to 7.0 (mol)% with respect to all the acid components constituting the polyester. If the content is less than 2.0 (mol)%, the adhesiveness to the polyamide may be insufficient, and a partial peeling may occur during handling in the next step. On the other hand, if it exceeds 7.0 (mol)%, spinnability tends to be difficult. The base polyester for copolymerizing 5-sodium sulfoisophthalic acid is mainly polyethylene terephthalate or polybutylene terephthalate, but a copolymer or a mixture thereof may be used. Of course, known third component copolymers, for example, acid components such as isophthalic acid, phthalic acid, adipic acid and sebacic acid, trimethylene glycol,
Cyclohexane-1,4-dimethanol, hexanediol, diethylene glycol, neopentyl glycol,
Glycol components such as propylene glycol, or
Those obtained by copolymerizing polyalkylene glycol, glycerin, pentaerythritol, methoxypolyalkylene glycol, bisphenol A, etc. in an amount of less than 15 mol% based on the total acid components can also be used.

Among the composite fibers (A) described above, the composite fiber composed of nylon-6 and polyethylene terephthalate copolymerized with 5-sodium sulfoisophthalic acid component has a reversible change in the crimp form due to water absorption and drying. It is particularly preferable because the fiber structure obtained is large and excellent in bulk settling property, feeling like feather, drape property and the like.

The polymer constituting the composite fiber (A) includes:
One or both of them may contain additives such as a matting agent such as titanium oxide, a fluorescent whitening agent, a dye, a pigment, an antioxidant, and an ultraviolet absorber.

The composite fiber (A) may have any cross-sectional shape as long as the component (A-m) and the component (A-S) are bonded to each other in a laminated type or an eccentric type as described above. Is also good.
For example, FIGS. 1 (a), 4 (a) to (c),
Even if the side-by-side type composite fiber shown in FIGS. 5 and 6 is used, the hollow side-by-side type composite fiber shown in FIG. 1 (b) and the eccentric type composite fiber shown in FIG. There may be.

The compound ratio of the component (A-m) and the component (AS) is in the range of 10:90 to 90:10, preferably 30; 70 to 70:30, in order to effectively exhibit the effects of the present invention. It is desirable to set. Outside this range, the change in elongation and shrinkage due to water absorption and drying tends to be insufficient, and the change in crimp form tends to be small.

Although the cross-sectional shape of the conjugate fiber is arbitrary as described above, in order to further increase the change in the crimped form due to water absorption / drying, the distance between the center of gravity of the (A-m) component and the (A-S) component is determined. Preferably, it is larger. For example, FIG.
When Comparing the cemented type composite fibers shown in FIG. 4 (a), the same if the cross-sectional area is also the same composite ratio, the center of gravity distance l ₃ of FIG. 4 (a) Figure 1 (a) Distance between the centers of gravity
greater than l _0, the second moment for fiber deformation due to water absorption and drying is increased, i.e., the change in crimp form becomes larger. Moreover, since the fiber surface area is large and the water absorption / drying speed is high in FIG. 4 (a), the crimped form is deformed in a short time. As shown in FIG. 4 (a), the one in which the distance between the centers of gravity is increased is preferable in that the deformation of the fiber structure is large and the response is fast.

Further, in the composite fiber having a flat cross-sectional shape shown in FIG. 4 (c), since the distance between the centers of gravity is short, the stress of the crimping form change is small and the deformation of the fiber structure is small, but the water absorption /
Since the drying speed is extremely high, there is an advantage that the deformation response of the fibrous structure is fast.

In addition, in the hollow laminated conjugate fiber shown in FIG. 1 (b), as shown in FIG. 4 (a), the distance between the centers of gravity is large and the fiber surface area is large, so that the deformation of the fiber structure is large. It has the advantage of quick response. In this case, the shape of the hollow portion may be any one of a circle and a polygon, and the number of the hollow portions may be plural, such as 2 to 10. However, the hollow ratio is desirably 3 to 45%.

As described above, as the cross-sectional shape of the conjugate fiber, it is preferable to increase the distance between the centers of gravity of the (A-m) component and the (A-S) component in order to increase the change in the crimp form due to water absorption and drying. However, it is particularly desirable that the following expression be satisfied.

L / L ₀ > 1 In order to produce the composite fiber (A) used in the present invention, a conventionally known composite spinning method may be employed as it is.

For example, as shown in FIG. 3 (a), the conjugate fiber shown in FIG. 1 (a) is obtained by disposing the (A-m) component and the (A-S) component in a lamination type, and then forming the nozzle hole N What is necessary is just to discharge from. The composite fiber shown in FIG. 1 (b) may be a composite spinneret having a C-shaped slit as shown in FIG. 2, or an eccentric type composite shown in FIG. 1 (c). As the fiber, as shown in FIG. 3 (b), an eccentric type composite spinneret having a core component flowing down from a position eccentric to the nozzle hole N may be used.

The spun undrawn yarn is further drawn. Depending on the processing conditions, the component disposed outside the three-dimensional crimped form is the above-mentioned (A-m) component or the (A-S) component. Can be set arbitrarily. For example, when nylon-6 is used as the (A-m) component and 5-sodium sulfoisophthalic acid copolymerized polyethylene terephthalate is used as the (A-S) component, the undrawn yarn is subjected to maximum drawing in hot water at 50 to 70 ° C. After the first stage stretching at a stretching ratio of 75 to 98% of the stretching ratio,
Nylon 6 (A-m) can be placed inside the three-dimensional crimped form by performing the restriction shrinkage treatment at 0.75 to 0.98 times in hot water at ~ 95 ° C. On the other hand, when the drawn yarn is further heat-treated in a tensioned state at 140 to 200 ° C., the nylon 6 can be arranged outside the three-dimensional crimped form. In the former, the number of crimps decreases when the fiber absorbs water, whereas in the latter, the number of crimps increases when the fiber absorbs water and decreases when the fiber dries.
Therefore, the arrangement of the composite fibers can be set to any one according to the purpose of use.

Next, the drawn fiber thus obtained is provided with a treating agent, and is further subjected to mechanical crimping if necessary, heat-treated, and then cut into a predetermined fiber length.

In the present invention, various treatment agents are used in order to impart various properties to the obtained fiber structure. For example, in order to impart hydrophilicity, a polyvinyl alcohol-based treating agent, a polyether / ester block copolymer-based treating agent, various nonionic, anionic or cationic hydrophilic treating agents, or a treating agent combining these are used. The resulting fibrous structure is suitable for batting of sports and winter clothing, filling of futons and bedding, surface materials of sanitary materials, household goods such as towels and tissues, and the like.

In order to impart water repellency, a fluorine compound,
Various water repellents such as organic silicone compounds, mineral oils, waxes, fatty acid esters, hydrocarbons, higher alcohols, higher fatty acids, and the like, or a combination thereof are used. And the resulting fiber structure is outwear
Filling of working wear for special work, table cloth
Suitable for applications that dislike water, such as interior goods and industrial materials.

The fineness of the conjugate fiber should be 0.5 to 60 denier from the viewpoints of card permeability, papermaking property, ease of bulk change and area change of the fiber structure due to water absorption and drying during the production of nonwoven fabric and wadding, etc. In order to further exhibit the effect of change in bulk and change in area, it is particularly desirable to set the denier to 2 to 45 denier.

On the other hand, the fiber length and the number of crimps are slightly different depending on the application.
For example, in the use of wet nonwoven fabrics such as papermaking, the fiber length 2-30
mm, particularly 3 to 20 mm. Since the number of crimps greatly affects papermaking properties, it is desirable that the number of crimps is small at the time of water absorption. It is desirable to reduce the number of contractions to 0 to 20/25 mm, especially 0 to 10/25 mm. On the other hand, it is desirable that the increase in the number of crimps during drying is large in order to increase the bulk change and area change of the nonwoven fabric. The number of crimps after drying at 60 ° C. for 1 hour is 5 to 50/25 mm, It is desirable to increase the number of crimps by 2/25 mm or more, especially 5/25 mm or more.

In applications such as dry nonwoven fabric, wadding, and spun yarn for clothing, the fiber length is desirably 20 to 150 mm, particularly 30 to 70 mm, from the viewpoint of carding properties. From the point, 6-30 pieces after drying at 60 ° C for 1 hour / 2
It is suitable to be 5 mm, especially 8 to 25 pieces / 25 mm. This number of crimps is 2/25 mm more than the number of crimps under the above-mentioned water absorption condition in order to cause deformation of the fiber structure by water absorption.
As described above, it is particularly preferable that the number of crimps differs by 5 pieces / 25 mm or more, and the number of crimps after water absorption is in the range of 0 to 100 pieces / 25 mm.

Next, the binder fiber (B) used in the present invention may be a fiber consisting of a heat-adhesive component alone or a composite fiber with another fiber-forming component. Above all, the former binder fiber is not melted during the heat bonding process and stays in a fiber form. The binder fiber becomes suitable and heat-bonds and fixes the composite fiber (A) in a mesh form. -It is preferable because it does not hinder the change in crimped form due to drying, and the bulk change and area change of the fibrous structure increase.

On the other hand, when a conjugate fiber is used as the binder fiber (B), the crimped morphological change of the conjugate fiber (A) during water absorption and drying tends to be hindered as described above. It is desirable to make it 5% or shorter than the composite fiber (A). For example, for papermaking 1-25mm, especially 1.
5 ~ 15mm, 15 ~ 140mm for non-woven fabric and cotton filling, especially
15-65mm is suitable.

The heat-adhesive component polymer constituting the binder fiber (B) has a melting point (softening point in the case of an amorphous polymer) of 80 to 230 ° C, preferably 100 to 200 ° C. 8
When the temperature is lower than 0 ° C., sticking between fibers is liable to occur during spinning. On the other hand, when the temperature is higher than 230 ° C., there is a tendency that the bonding treatment cannot be performed with a normal heat bonding machine.

As such a heat bonding component, for example, polyethylene,
Polypropylene, polybutene-1, polypentene-1, ionomer resin, ethylene-vinyl acetate copolymer, polyvinyl acetate, polyacrylate, or copolymers thereof; polystyrene; polyamide such as nylon 6, nylon 10, nylon 12, Or a copolymer thereof; polyvinyl chloride; polyvinylidene chloride; polyurea; polyurethane, or a copolymer thereof; an acid component such as terephthalic acid or isophthalic acid, and ethylene glycol, butylene glycol, pentamethylene glycol, or hexamethylene glycol. And / or polyoxyalkylene glycols such as dimethylene glycol and polyethylene glycol and / or polyhydric alcohols such as glycerin and pentaerythritol. And a mixture of et. Among them, a modified polyester obtained by copolymerizing a 5-sodium sulfoisophthalic acid component in an amount of 2 to 7 mol% based on the total acid component, and tetramethylene glycol and / or hexanediol in an amount of 50 mol% or more based on the glycol component, It is preferable to use a fiber composed of a polyamide and a polyester as the conjugate fiber (A) because both exhibit good adhesiveness. Moreover, since the modified polyester is rich in flexibility, it also has an advantage that the composite fiber (A) constituting the fibrous structure does not suppress the change in the crimp shape due to water absorption and drying.

Further, among the above polyester copolymers, a polyalkylene glycol component having an average molecular weight of 500 to 10,000, such as polyethylene glycol and polybutylene glycol, is used in an amount of from 5 to 5.
Since the modified polyester copolymerized at 50% by weight has elasticity, it is preferable because it does not suppress the change in the crimped form of the composite fiber (A) due to water absorption and drying.

The binder fiber (B) in the present invention may be a core-sheath type or laminated conjugate fiber in which another fiber-forming component is bonded, as described above, in addition to the fiber composed of only the heat bonding component. . In this case, the eccentric core-sheath type or the laminating type develops a crimp by heat treatment at the time of thermal bonding and turns into a spiral crimp, thereby generating spring-like elasticity. As a result, the movement of the composite fiber (A) in the fiber structure becomes easy,
There is an advantage that a change in the crimping form during water absorption and drying, that is, a change in the bulk and area of the fiber structure becomes easy.

The fiber-forming component constituting such a composite binder fiber is not particularly limited as long as it has a melting point at least 20 ° C. higher than the melting point of the heat bonding component, but usually polyester, polyamide, polyolefin or the like is used. The ratio is set so that the heat-adhesive component is in the range of 20-70%.

The cross-sectional shape of the composite binder fiber may be either the core-sheath type or the laminating type as described above. For example, a hollow core-sheath type composite fiber as shown in FIG. 1 (c), a hollow side-by-side type composite fiber as shown in FIG. 7, a solid core-sheath type composite fiber, a hetero hollow composite fiber and the like. Can be taken.

In addition, since the hollow core-sheath type composite binder fiber has a hollow portion, bulkiness is also improved, and from this point, the ratio of the hollow portion is preferably set to 3 to 30%. The shape of the hollow portion is arbitrary, such as a circular shape or a polygonal shape, and the number of the hollow portion may be two or four or more.

The binder fiber (B) described above is obtained by stretching an undrawn yarn obtained by melt-spinning, applying a processing agent necessary for post-processing, applying crimping if necessary, and then performing a heat treatment. It is obtained by cutting into a predetermined fiber length as described above.

The fineness of the binder fiber (B) is preferably from 0.5 to 20 denier from the viewpoints of card passing property and papermaking property at the time of nonwoven fabric production. The number of crimps slightly varies depending on the application. For example, for papermaking, the number of crimps is 0 to 20/25 mm, and for dry nonwoven fabric and clothing, the number of crimps is 6 to 40/25 m.
m is suitable.

In addition, optional additives such as a matting agent, a flame retardant, a deodorant, and an ultraviolet absorber can be added to each component of the binder fiber (B) as long as the object of the present invention is not impaired. .

In the fiber structure of the present invention, it is important that 50 to 95% by weight of the conjugate fiber (A) is thermally bonded and fixed by 50 to 5% by weight of the binder fiber (B). If the amount of the binder fiber (B) exceeds 50% by weight, the number of heat-bonded fixing points of the conjugate fiber (A) increases, and the bulk and area change due to water absorption and drying of the fibrous structure decreases, which is not preferable. . On the other hand, when the content is less than 5% by weight, the number of thermal bonding points becomes too small, the bulk / area change of the fibrous structure due to water absorption and drying becomes small, and the fibrous structure is cut by external force, This is not preferred because of the shape of the film.

Further, the basis weight of the fiber structure is 5 g / m ² or more, preferably 10 g.
/ m ² or more. If less than this range,
The amount of the conjugate fiber (A) used is reduced, and the bulk and area change of the fiber structure accompanying water absorption and drying are undesirably reduced.

Furthermore, the bulk of the fiber structure needs to be 10 cm ³ / g or more in order to facilitate the change in the crimped form due to water absorption and drying of the composite fiber (A) and to increase the bulk and area change of the fiber structure. . If the bulk is less than this range, the composite fiber (A)
Of the fibrous structure becomes small, and the change in the area of the fibrous structure becomes small, which is not preferable.

Further, the fiber structure of the present invention needs to have a bulk change of 5% or more in practical use after being treated under the following water absorbing and drying conditions.

Drying condition: drying at 60 ° C for 1 hour Water absorbing condition: absorbing moisture at 30 ° C for 2 hours at 90% relative humidity If this bulk change is less than 5%, the bulk and area change due to water absorption and drying of the fiber structure is insufficient. For breathability,
Changes in heat retention, filter properties, hand feeling, etc., become practically insufficient. When the content is 5% or more, these characteristics are good.
When the content is 20% or more, the change in the above characteristics becomes remarkable, which is more preferable.

The fiber structure of the present invention may be any other fiber as long as the object of the present invention is not impaired, for example, natural fibers such as cotton, wool, and wood pulp, and ordinary synthetic fibers such as polyester, nylon, and polypropylene. May be used in combination. The amount varies depending on the type of the fiber used in combination. However, the amount of the conjugate fiber (A) constituting the fiber structure should be at least 50% by weight or more based on the weight of the fiber structure. Is preferred.

The fibrous structure of the present invention described in detail above is partially heat-bonded and fixed by the binder fiber, but has a space where the conjugate fiber (A) can freely change its form. Therefore, when the crimped form of the composite fiber (A) changes due to water absorption and drying, the form of the fiber structure changes reversibly.

For example, (Case 1) The number of crimps in a dry state is 20 pieces / 25m
m, when using a composite fiber (A) that changes to 7 / 25mm in the water-absorbing state, the apparent fiber length in the water-absorbing state increases,
The bulk of the fiber structure increases, and at the same time, the area increases. Further, since the crimp is reduced, the air permeability is increased, and the feeling is also soft.

On the other hand, (Case 2) the number of crimps in a dry state is 14/25 mm,
When the composite fiber (A) of 60 pieces / 25 mm is used in the water absorbing state, the apparent fiber length in the water absorbing state is shortened, the bulk density of the fiber structure is increased, and the area is also reduced at the same time. In addition, since the crimp increases, the air permeability decreases, and the heat retention and the filterability are improved, but the feeling becomes harder.

Since the fiber structures of (Case 1) and (Case 2) each have the above-described characteristics, they may be appropriately selected and used according to the purpose of use. For example, the former fiber structure is used for sports clothing and summer skin. It is suitable for applications such as futons, covering materials for medical or sanitary materials, summer underwear, and the like, while the latter is suitable for uses such as batting for winter clothes and futons for winter.

(Effects of the Invention) The fiber structure of the present invention has a larger bulkiness and area change due to water absorption and drying compared to the conventional fiber structure, and the shape of the fiber structure is almost constant even after repeated water absorption and drying. No change in shape stability. Also, even if strong external force is applied,
It has excellent characteristics that it does not break or become dango and has good durability against external forces.

Furthermore, it is characterized in that it is heat-bonded and fixed, so that it has less fluff and high breaking strength, and that the composite fiber (A) has a spiral crimp and is soft and elastic.

The fiber structure of the present invention can be used alone or as a base material for diapers, napkin surface materials / cushion materials, civil engineering materials, oil absorbents, various felts, futon hardened cotton, filters, compresses, etc. by taking advantage of these advantages. Used in a laminated form (including lamination with other materials). In the field of wet nonwovens,
A fiber structure thermally bonded at the temperature of a Yankee dryer of a paper machine (100 to 120 ° C.) is used. For the purpose of improving the filterability of the nonwoven fabric, it may be used as a composite product in which a film or a nonwoven fabric is laminated on papermaking.

It is needless to say that the uses listed here are examples of main ones, and the uses of the fiber structure of the present invention are not limited to these.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.

Examples 1-4, Comparative Examples 1-4 Nylon 6 having an intrinsic viscosity [η] of 1.1 (measured with an m-cresol solution at 30 ° C) and a melting point of 215 ° C as components (A-m); The intrinsic viscosity [η] is 0.45 (25
254 ° C)
Of 5-sodium sulfoisophthalic acid component 3.5 mol% copolymerized polyethylene terephthalate in a 50: 5
The mixture was melt extruded at 275 ° C. from a spinneret having 1200 holes at a spinning speed of 100.
The fiber was drawn at 0 m / min to obtain an undrawn composite fiber having a hollow cross section of 10% as shown in FIG. 1 (B). Next, the undrawn conjugate fiber was drawn three times in a hot water bath at 65 ° C.
After a 10% heat-restriction heat treatment in a warm water bath, a crimp of 8 pieces / 25 mm is applied by an indentation crimping machine, and a relaxation heat treatment is performed at 140 ° C. for 30 minutes to develop a latent crimp, and then a fiber length of 51 mm is obtained. Cut. The denier of the obtained composite fiber is 3 deniers, the number of crimps after drying at 60 ° C. for 1 hour is 20/25 mm, and the number of crimps after leaving in an atmosphere of 30 ° C. and 90% relative temperature for 2 hours is 7/25 mm. Met.

On the other hand, 3 mol% of 5-sodium sulfoisophthalic acid and 15 mol% of isophthalic acid having an intrinsic viscosity [η] of 0.85 (measured with an O-chlorophenol solution at 25 ° C.) and a melting point of 120 ° C. are copolymerized. Polyhexamethylene terephthalate was passed through a die having a hole diameter of 0.3 mm, the number of holes, and 3,500 holes.
Melt extrusion at 00 ° C, take up at 1000m / min spinning speed,
An undrawn fiber having a circular cross section was obtained.

Next, the undrawn fiber was drawn 3.8 times in a hot water bath at 65 ° C., and the number of crimps after the relaxation heat treatment was 13 pieces / 25 m by an indentation crimping device.
It was crimped so as to obtain m, and was subjected to relaxation heat treatment at 100 ° C. for 30 minutes, and then cut into a fiber length of 32 mm. The fineness of the obtained binder fiber was 3 denier.

The conjugate fiber was humidified, the number of crimps was set to 16/25 mm, the binder fiber was mixed with the mixture in the ratio shown in Table 2, defibrated, carded to form a web, and circulated with hot air. Heat treatment was performed at 140 ° C. for 2 minutes in a mold heat treatment machine to prepare an adhesive web (nonwoven fabric) having a basis weight and bulkiness described in Table 2, and a change in bulk and a feeling in water absorption and drying were evaluated.

The bulkiness can be measured by water absorption (after leaving the nonwoven fabric in an atmosphere at 30 ° C. and 90% relative humidity for 2 hours) before and after compressing 50 nonwoven fabrics repeatedly at an interval of 1 minute 50 times under a load of 5 g / cm ^{2 with} a load of 5 g / cm ^2. ), And was calculated from the thickness of the non-woven fabric at the time of non-loading after drying (after drying at 60 ° C. for 1 hour).
It was calculated from the following equation.

The results are shown in Tables 1 and 2.

Example 5 In Example 1, the undrawn conjugate fiber was drawn three times in a hot water bath at 65 ° C., subjected to a 10% limited shrinkage heat treatment in a hot water bath at 95 ° C., then subjected to a tension heat treatment at 180 ° C. for 8 seconds, and then pushed. After applying a crimp with a crimping machine and performing a relaxation heat treatment at 140 ° C. for 30 minutes, a latent crimp of 14 crimps / 25 mm was developed, and then cut to a fiber length of 51 mm in the same manner as in Example 1. A web was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 6, Comparative Example 5 In Example 1, 5 mol% as the (As) component of the conjugate fiber, having an intrinsic viscosity [η] of 0.40 and a melting point of 252 ° C.
Using polyethylene terephthalate copolymerized with 5-sodium sulfoisophthalic acid (Example 6)
And the case of using polyethylene terephthalate copolymerized with 1 mol% of 5-sodium sulfoisophthalic acid having a limiting viscosity [η] of 0.50 and a melting point of 257 ° C. (Comparative Example 5), and otherwise using Example 1 A web was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 2.

The nonwoven fabric of Example 6 had a large bulk change due to drying and water absorption, had a soft feel, and had good shape retention (hetari resistance). However, the nonwoven fabric of Comparative Example 5 was made of nylon when drawing the conjugate fiber. 6 (A-m) and the copolymerized polyethylene terephthalate (A-s) were partially peeled off, and the change in crimped form due to dry water absorption was small, and the change in bulk of the obtained web was also small, so the evaluation was stopped.

Example 7 In Example 1, as the binder fiber (B), polyethylene terephthalate of [η] 0.64 and the same polyhexamethylene terephthalate-based polyester as used for the binder fiber of Example 1 were combined at a composite ratio of 50/50 (weight ratio). ) Has a hollow side-by-side cross section as shown in Fig. 7 and has a fineness of 3 deniers and a number of crimps of 23 / 25mm
Example 1 except that a composite binder fiber having a fiber length of 32 mm (solid crimp) and a fiber length of 32 mm was used, and the composite fiber of Example 1 was used as the composite fiber (A), and the mixing ratio was 80/20 (A / B). In the same manner as in the above, a nonwoven fabric was obtained. The results are shown in Tables 1 and 2.

Compared with Example 1, the bulk change rate was slightly inferior, but good results were obtained.

Example 8 In Example 7, 5 mol% of 5-sodium sulfoisophthalic acid, 40 mol% of isophthalic acid, and 40 mol% of tetramethylene glycol were used as the thermal adhesive component of the binder fiber (B) based on the terephthalic acid component. Copolymerized,
A nonwoven fabric was obtained in the same manner as in Example 7, except that the copolymerized polyethylene terephthalate having an intrinsic viscosity of 0.50 and a melting point of 155 ° C was used. The results are shown in Tables 1 and 2.

Since the heat bonding component used for the binder fiber (B) was slightly hard, the obtained nonwoven fabric was slightly harder than that of Example 7, but had no problem in practical use.

Example 9 A nonwoven fabric was obtained and evaluated in the same manner as in Example 8, except that the composite fiber having a fiber cross-sectional shape shown in FIG. 1A was used as the composite fiber (A). The results are shown in Table 1,
It is shown in Table 2.

The polymers used in Table 1 are as follows.

(A): 5-sodium sulfoisophthalic acid 3.5 mol% copolymerized polyethylene terephthalate (a): 5 mol% copolymerized polyethylene terephthalate (c): 1 mol% copolymerized polyethylene terephthalate (d): 3 mol% Isophthalic acid 15 mol% copolymerized polyhexamethylene terephthalate (e): 5-sodium sulfoisophthalic acid 3 mol%, isophthalic acid 40 mol%, and tetramethylene glycol 40
Mol% copolymerized polyethylene terephthalate (f): polyethylene terephthalate where the copolymerization amount is mol% based on the terephthalic acid component.

[Brief description of the drawings]

FIGS. 1 and 4 to 7 are examples showing a cross-sectional view of the conjugate fiber (A) used in the present invention, and FIG. 2 obtains the conjugate fiber (A) of FIG. 1 (b). Is an example of a spinning process for forming a hole. FIG. 3 shows FIGS. 1 (a) and 1 (a), respectively.
It is sectional drawing which shows an example of the spinneret polymer inlet part at the time of manufacturing the conjugate fiber (A) shown to (c). A-s: a component with a small change in expansion and contraction due to water absorption and drying Am-a component with a large change in expansion and contraction due to water absorption and drying G _A : the center of gravity of the As component G _B : the center of gravity of the _Am component l _0-8 ： Distance between centers of gravity N: Spinning S: Slit H: Hollow

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Yoshida 3-4-1, Amihara, Ibaraki-shi, Osaka Teijin, Ltd. Osaka Research Center Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) D04H 1 / 42 D04H 1/54

Claims (4)

(57) [Claims] (1) 50 to 95% by weight of a composite fiber (A) bonded to a lamination type or an eccentric type, which causes a reversible change in a crimp form with a change in water absorption / drying, is a binder fiber (B) A fibrous structure heat-bonded and fixed by 50 to 5% by weight, the basis weight of the structure is 5 g / m ² or more, and the bulk is 10 cm ³ / g.
A fibrous structure having a bulk change of 5% or more as measured under the following conditions of water absorption and drying. 2. A conjugate fiber (A) comprising a polyamide and a 5-sodium sulfoisophthalic acid component in an amount of 2 to 2 with respect to the acid component.
The fiber structure according to claim 1, which is a composite fiber comprising a modified polyester copolymerized with 7 mol%. 3. The thermal bonding component of the binder fiber (B) is 5
A modified polyester having a melting point of 80 to 230 ° C. obtained by copolymerizing sodium sulfoisophthalic acid component in an amount of 2 to 7 mol% based on the acid component and tetramethylene glycol and / or hexane diol in an amount of 50 mol% or more based on all glycol components. The fiber structure according to claim 1, wherein 4. The fiber structure according to claim 1, wherein the cross-sectional shape of the conjugate fiber (A) is a hollow cross-section.