JPH03213547A - Textile material - Google Patents

Abstract

PURPOSE:To obtain the subject textile material excellent in shape retention and durability to external force and useful for a diaper, etc., by bonding specified conjugate fibers by means of thermal adhesion using binder fibers and specifying the weight and the bulkiness, respectively. CONSTITUTION:An objective textile material produced by bonding (A) 50-95wt.% conjugate fibers united into a lamination type or an eccentric type and showing reversible changes of crimp state in accordance with water absorption-drying change by the thermal adhesion method using (B) 50-5wt.% binder fibers and having >=5g/m<2> weight, >=10cm<3>/g bulkiness and <=5wt.% difference of bulkiness between the value measured under a drying condition at 60 deg.C for 1hr and that measured under a water absorbed condition at 30 deg.C and relative humidity of 90% for 2hr.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a composite fiber whose crimp form reversibly changes due to moisture absorption or water absorption (hereinafter collectively referred to as water absorption) and drying, which is thermally bonded using a binder fiber. This invention relates to a fixed fiber structure. More specifically, since the composite fibers are bonded and fixed in a mesh shape by binder fibers, the volume and area of the fiber structure change greatly due to water absorption and drying, and it is reversible and reproducible, and it has a soft texture. It relates to a fiber structure that exhibits excellent mechanical properties.

(Prior Art) It is well known that the crimp rate of natural fibers such as cotton and a single feather of wool changes reversibly with changes in humidity.

On the other hand, as synthetic fibers whose crimp rate changes reversibly with changes in humidity, acrylic synthetic fibers are disclosed in JP-A No. 55-93860, and acrylic synthetic fibers are disclosed in JP-A-57-66.
No. 162, JP-A No. 57-95360 discloses polyester synthetic fibers, and JP-A No. 63-44843 discloses polyester synthetic fibers.
Polyester/nylon synthetic fibers are disclosed in Japanese Patent Publication No. 63-44844.

However, when these fibers are used as padding for futons, pillows, etc. or as padding for cold-weather clothing, bedding, etc., (1) the change in bulk due to water absorption and drying is small, and (2) the form of the fiber structure. It has drawbacks such as poor stability (3) poor bulk recovery properties against repeated deformation, and has not yet been practically satisfactory. That is, (1) Since the fibers are not bonded and fixed within the fiber structure, changes in the crimp form of the composite fibers do not manifest 100% as changes in the volume and area of the fiber structure. ■When the crimped form of the composite fiber is not repeated, the fibers slide against each other, so the initial fiber arrangement and the fiber arrangement after repeated deformation become different and the form changes. ■Since the fibers are not adhesively fixed, if external force is repeatedly applied, the fibers become entangled and form a tango, resulting in insufficient bulk recovery. It had the following drawbacks. Furthermore, when worn, cotton filling density unevenness occurs,
It also had practical problems such as reduced heat retention and loss of shape.

Also known is a method in which a web is formed from such synthetic fibers, then sprayed with a liquid adhesive such as latex, and then heat treated. However, although it is relatively good in the case of a web with a low basis weight, when the basis weight exceeds 5 g/m, it becomes difficult to uniformly apply the liquid adhesive.
Problems 1) to (3) are still unsolved. Also,
Since liquid adhesives are usually water-based, they also have the fatal flaw that the adhesive points come off when washed.

On the other hand, obtaining a fiber structure using a latent crimp composite fiber and a binder fiber is disclosed in Japanese Patent Publication No. 43-920, Japanese Patent Publication No. 42-21318, and Japanese Patent Publication No. 1-2125.
It is well known from publications such as Publication No. 7. However, in these fibrous structures, binder fibers prevent misalignment between fibers and improve dimensional stability, and the bulk is rather kept unchanged. therefore,
It was completely unknown in the past that by adhesively fixing composite fibers in a network shape with binder fibers as in the present invention, changes in the crimp form of the composite fibers could be made to respond extremely effectively to changes in volume and area. It is.

(Objective of the Invention) The present invention eliminates the various drawbacks of the conventional fiber structures made of composite fibers that cause crimp rate changes due to water absorption and drying, and eliminates the bulk and area changes of the fiber structures due to water absorption and drying. The object of the present invention is to provide a novel fibrous structure that is large, reversible, has excellent dimensional reproducibility, exhibits a soft texture, and is resistant to breakage even under external forces.

(Structure of the Invention) As a result of intensive studies to achieve the above object, the inventors of the present invention have found that by thermally bonding and fixing composite fibers that undergo crimped form changes due to water absorption and drying using binder fibers. - It has been discovered that a fiber structure with a large area change and excellent reversibility and dimensional reproducibility can be obtained, and the present invention has been achieved.

That is, in the present invention, 50 to 95% by weight of composite fibers (^) bonded in a laminated type or eccentric type, which reversibly change the crimp form due to changes in water absorption and drying, are combined with a binder. Fiber (B) A fiber structure thermally adhesively fixed with 50 to 5 weight percent, and the basis weight of the structure is 5 g/r+f
The above is a fiber m relic characterized by having a bulk of 10a; t/g or more and a change in volume of 5% or more when measured under the following water absorption and drying conditions.

The composite fiber used in the present invention must reversibly change its crimp form upon water absorption and drying, but in order to do so, one component of the composite fiber must elongate more than the other after absorbing water and drying.・Shrinkage change is large, so it is necessary to use a composite type such as a laminated type or an eccentric type.

In the case of a laminated type, the fibers after spinning and drawing usually take the form of three-dimensional crimp. The changes in the crimped form due to water absorption and drying differ depending on whether the component that undergoes greater elongation and contraction changes due to water absorption and drying is placed on the outside or inside of the three-dimensional crimped form. Note that this arrangement relationship changes not only depending on the combination of polymer components used but also depending on the spinning conditions such as spinning, stretching, and heat treatment.

If a component that expands when water is absorbed and contracts when drying is placed on the outside of a composite fiber that takes the form of three-dimensional crimp, the number of three-dimensional crimp increases when the fiber absorbs water and decreases when drying. , the number of steric crimp decreases when water is absorbed and increases upon drying. This change in the three-dimensional crimp 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 express the change in the three-dimensional crimp form more effectively, elongation due to water absorption and drying is required. - It is preferable to arrange the component with a large shrinkage change in the sheath part, and the core part may be partially exposed.

Such eccentric conjugate fibers have the advantage that they do not peel off even when polymer components with low adhesiveness are used together, but on the other hand, they are inferior to laminated fibers in changing the crimp form due to water absorption and drying. Therefore, in the present invention,
It is more preferable to use a composite fiber made by laminating polymers with good adhesiveness to each other to form a composite fiber, since the resulting fiber structure has a large change in volume.

A component (^-I) that composes the composite fiber (^) used in the present invention, which expands more when it absorbs water and shrinks more when it dries.
Examples of n) include polyamide, water-absorbing polyester, and water-absorbing polyolefin. Among these, polyamide is more preferable because it has a large degree of elongation due to water absorption and shrinkage due to drying, and the resulting fiber itself has a soft texture and less bulk loss.

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

The polyamide having the first general type is a polymer obtained by polycondensing aminocarboxylic acids such as 6-aminocaproic acid, 9-aminononanoic acid, and 11-aminoundecanoic acid or derivatives thereof, such as ε-ca 10-lactam. The other is a polymer obtained by polycondensing a diamine and a dibasic acid or an amide-forming derivative thereof.

Suitable examples of the diamine include ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, decamethylenediamine, m-xylylenediamine, P--1r silylenediamine, m-phenylenediamine, Examples of suitable dibasic acids are sebacic acid, superric acid, adipic acid, azelaic acid, undecanedioic acid, glutaric acid,
These are pimelic acid, tetradecanedioic acid, isophthalic acid and terephthalic acid, but the amide-forming derivatives can also be replaced by the above-mentioned diamines and/or dibasic acids.

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

Examples of the component (^-8) that composes the composite fiber (A) and which exhibits small changes in elongation and contraction due to water absorption and drying include polyester, polyolefin, etc.; Polyester is particularly preferred from the viewpoint of web formability and the like.

In particular, when polyamide is used as the component (^-I11), 5-sodium sulfoisophthalic acid is added in an amount of 2.0 to 7.0 with respect to the total acid components constituting the polyester.
(Mole) % Valve type combination is preferred.

If the amount is less than 0.02.0 (mol)%, the adhesion to the polyamide may be insufficient, resulting in partial peeling during handling in the next step. On the other hand, if it exceeds 7.0 (mol)%, spinnability tends to become difficult. The base polyester to be copolymerized with 5-sodium sulfoisophthalate is mainly polyethylene terephthalate or polybutylene terephthalate, but copolymers and mixtures thereof may also be used.

Of course, examples of known third component copolymers as long as they do not impair basic performance include acid components such as isophthalic acid, phthalic acid, adipic acid, and sebacic acid, trimethylene glycol, cyclohexane-1,4-dimetatool, and hexanediol. ,
It is also possible to use glycol components such as diethylene glycol, neopentyl glycol, and propylene glycol, or those copolymerized with less than 15 mol% of polyalkylene glycol, glycerin, pentaerythritol, methoxypolyalkylene glycol, bisphenol A, etc. based on the total acid component. be.

Among the conjugate fibers (A) described above, conjugate fibers made of polyethylene terephthalate 1 to which N-10-6 and 5-sodium sulfoisophthalic acid components are copolymerized are crimped by water absorption and drying. It is particularly preferred because the change in form is reversible and large, and the final fiber structure obtained has excellent bulkiness, feather-like texture, drapability, etc.

Note that one or both of the polymers constituting the composite fiber (A) contain a matting agent such as titanium oxide.

Additives such as optical brighteners, dyes, pigments, antioxidants, and ultraviolet absorbers may also be included.

Composite fiber (A) may have any cross-sectional shape as long as component (A-11) and component (A-3) are joined in a laminated or eccentric manner as described above. Good too.

For example, FIG. 1(a), FIG. 4(a) to (C),
Even if it is a side-by-side type conjugate fiber as shown in Figures 5 and 6, it can be a hollow side-by-side type conjugate fiber as shown in Figure 1(b), or even a centering type conjugate fiber as shown in Figure 1(C). It may be.

In order to effectively exhibit the effects of the present invention, the composite ratio of component (8-m) and component (8-m) is 10:90 to 90:10.
2 Preferably, it is desirable to set it in the range of 30 near 0 to 70:30. Outside this range, changes in elongation and contraction due to water absorption and drying tend to be insufficient and changes in crimp form tend to be small.

The cross-sectional shape of the composite fiber is arbitrary as mentioned above, but
In order to increase the change in crimp form due to drying, it is preferable to increase the distance between the centers of gravity of the (A-In) component and the (A-3) component. For example, Fig. 1(a)
Comparing the laminated composite fibers shown in Figure 4(a), if the composite ratio is the same and the cross-sectional area is the same, then Figure 4(a)
The distance between the centers of gravity 13 is the distance between the centers of gravity in Figure 1 (a)! .

, the moment of inertia due to fiber deformation due to water absorption and drying becomes larger, that is, the change in crimp form becomes larger. Moreover, since the fibers shown in FIG. 4(a) have a larger surface area and a faster water absorption and drying rate, the crimped shape changes in a short time. In this way, Figure 4 (a
) is preferable because the distance between the centers of gravity is large, as the fiber structure is deformed largely and the response is fast.

3. In the composite fiber with the flat cross-sectional shape shown in Fig. 4 (C), the distance between the centers of gravity is short, so the stress caused by the change in crimp form is small, and the deformation of the fiber structure is small, but it is difficult to absorb water and dry. Since the speed becomes extremely high, there is an advantage that the deformation response of the fiber structure is fast.

In addition, in the hollow laminated composite fiber shown in Fig. 1(b), the distance between the centers of gravity is large and the fiber surface area is large, as shown in Fig. 4(a), so the deformation of the fiber structure is large. It also has the advantage of fast response. In this case, the shape of the hollow portion may be circular, polygonal, etc., and the number of hollow portions may be plural, such as 2 to 10. It is desirable that the hollowness ratio is 3 to 45%.

As mentioned above, the cross-sectional shape of the composite fiber is designed to increase the change in crimp form due to water absorption and drying (^-1'n)
Although it is preferable to increase the distance between the centroids of the component and the (8-8) component, it is particularly desirable that the following equation be satisfied.

L/LO>1 4 In order to produce such a composite fiber (Δ) used in the present invention, a conventionally known composite spinning method may be employed as is.

For example, the composite fiber shown in FIG. 1(a) is as shown in FIG. 3(a).
As shown in the figure, the (^-n) component and the (^-8) component may be arranged in a laminated mold and then discharged from the nozzle hole N. Moreover, the composite fiber shown in FIG. 1(b) may be produced by using a composite spinning die consisting of a C-shaped slit as shown in FIG. 2, or by using an eccentric type composite fiber as shown in FIG. For the fibers, as shown in FIG. 3(b), an eccentric type composite spinning nozzle may be used, which allows the core component to flow down from a position eccentric to the nozzle hole N.

The spun undrawn yarn is further subjected to a drawing process, and depending on the processing conditions, the component arranged outside the three-dimensional crimped form is made into the above-mentioned (^-m) component or (A-S) component. For example, when using nylon-6 as the (8-5 m) component and 5-sodium sulfoisophthalic acid copolymerized polyethylene terephthalate as the (A-8) component, the undrawn yarn can be set as desired. ~7
After the first stage stretching at a draw ratio of 75 to 98% of the maximum draw ratio in warm water at 0°C, 0.75 to 0.
．． Nylon 6 (A-m) if subjected to limited shrinkage treatment at 98 times
can be placed inside the three-dimensional crimp form. On the other hand, if this drawn yarn is further heat-treated under tension at 140 to 200°C, nylon 6 can be arranged on the outside of the three-dimensionally crimped form. Note that in the former case, the number of crimps decreases when the fiber absorbs water, whereas in the latter case, the number of crimps increases when the fiber absorbs water and decreases when it dries. therefore,
The composite fibers can be arranged in any way depending on the purpose of use.

Next, a treatment agent is applied to the thus obtained drawn fibers,
Further, the fibers are mechanically crimped if necessary, subjected to heat treatment, and then cut to a predetermined fiber length.

In the present invention, various types of processing agents are used in order to impart various properties to the resulting fibrous structure. For example, in order to impart hydrophilicity, polyvinyl alcohol-based processing agents, polyether/ester block copolymer-based processing agents, nonions, anions,
Various cationic hydrophilic treatment agents or a combination of these treatment agents are used, and the resulting fiber structures can be used as filling for sports and cold-weather clothing, stuffing for futons and bedding, and as surface materials for sanitary materials, towels, and tissues. Suitable for other household items such as.

In addition, in order to impart water resistance, fluorine compounds, organic silicone compounds, mineral oils, and waxes are used.

Fatty acid ester, hydrocarbon, higher alcohol, higher fat #! Various water repellent treatment agents or a combination of these treatment agents are used. The resulting fiber structure can be used as a filling material for outwear/special work wear,
Suitable for water-sensitive applications such as tablecloths, interior goods, and industrial materials.

The fineness of the composite fibers is determined by the card passability during the production of nonwoven fabrics and stuffed wire rings, paper-making properties, water absorption and drying.
．． It is preferably 5 to 60 deniers, and in particular, 2 to 45 deniers is preferred in order to more effectively increase the height and change the area.
It is preferable to use denier.

On the other hand, the fiber length and number of crimps vary depending on the use. For example, in wet nonwoven fabric applications such as paper making, the fiber length is 2 to 30.
IllII, especially 3 to 20II1m, is desirable.The number of crimp has a great effect on paper-making properties, etc., so it is desirable to have a small number of crimp when absorbing water.
90%) After leaving for 2 hours, the number of crimps is 0 to 20/25I
It is desirable to reduce the number to 1 m, especially 0 to 10 pieces/25M. On the other hand, in order to increase the height and area change of the nonwoven fabric during drying, it is desirable that the number of crimp increases as much as possible.
It is desirable that the number of crimps after drying for 1 hour is 5 to 50/25 mm, which is an increase of 2/25 mm or more, particularly 5/25 m or more, over the number of crimps during water absorption.

In addition, for applications such as dry non-woven fabrics, stuffed cotton, and spun yarn for clothing, the fiber length is 20-150 mm, especially 3 (1-70 rm).
is desirable from the viewpoint of carding properties, and the number of crimps when dried is 6 to 30/251 nm, especially 8 to 25 after drying at 60°C for 1 hour from the viewpoint of carding properties.
A suitable setting is 25 pieces per 25 pieces. The number of crimps is 2 725 mm or more than the number of crimps under the water absorption condition in order to cause deformation of the fiber structure due to water absorption.
2. In particular, it is desirable that the difference be 5 crimp/25 mm or more, and the number of crimp after water absorption is within the range of 0 to 100 crimp/25 mm.

Next, the binder fiber (B) used in the present invention may be a fiber consisting of a thermal adhesive component alone, or a composite fiber with another fiber-forming component.

Among them, the former type of binder fiber is heated and melted during the thermal bonding process and does not retain its fiber form, but instead becomes a composite fiber (
Since A) is thermally bonded and fixed in the form of a mesh, it does not interfere with the +8 shrinkage shape change of the composite fiber (A) due to water absorption and drying, and the sophistication and area change of the fiber structure are increased, which is preferable.

On the other hand, when a composite fiber is used as the binder fiber CB), as mentioned above, there is a tendency that the change in the crimp form of the composite fiber (A) during water absorption and drying is hindered. In particular, it is desirable that the length be 5% or more shorter than the composite fiber (A). For example, for paper making, 1
-25 nm, especially 1.5-15 mm, and for non-woven fabrics and cotton padding, 15-140 nm, especially 15-65+ nm are suitable.

The thermoadhesive component polymer constituting the binder fiber (B) has a melting point (softening point in the case of a non-grade polymer) of 80 to 230°C2, preferably 100 to 200°C.
°C. If the temperature is less than 80°C, adhesion between fibers will not occur during spinning. On the other hand, if the temperature exceeds 230°C,
There is a tendency for ordinary thermal bonding processing machines to be unable to perform the bonding process.

Such thermal adhesive components include, for example, polyethylene, polypropylene, polybutene-1, polypentene-1, ionomer resin, ethylene vinyl acetate valve type polymer, polyvinyl acetate, polyacrylic acid ester, or copolymers thereof; polystyrene; nylon. 6. Nylon 10.
Polyamides such as nylon 12 or copolymers thereof; polyvinyl chloride; polyvinylidene chloride; polyurea; polyurethane or copolymers thereof; acid components such as terephthalic acid and isophthalic acid, and ethylene glycol and butylene glycol. , pentamethylene glycol. Examples include polyester copolymers in combination with glycols such as hexamethylene glycol, and/or polyoxyalkylene glycols such as diethylene glycol and polyethylene glycol, and/or polyhydric alcohols such as glycerin and pentaerythritol, or mixtures thereof. I can do it. Among these, modified polyesters are copolymerized with 2 to 7 mol% of 5-sodium sulfoisophthalic acid component based on the total acid component and 50 mol% or more of tetramethylene glycol and/or hexanediol based on the glycol component. It is preferable to use a composite fiber (^) made of polyamide and polyester because it exhibits good adhesion to both. Moreover, since this modified polyester is highly flexible, it also has the advantage of not suppressing changes in crimp form due to water absorption and drying of the composite fibers (A) constituting the fiber structure.

1 Among the above-mentioned polyester copolymers, modified polyesters obtained by copolymerizing 5 to 50% by weight of polyalkylene glycol components such as polyethylene glycol and polybutylene glycol with an average molecular weight of 500 to 10,000 have elastic properties, so they absorb water. - It is preferable because it does not suppress the crimp form change of the composite fiber (^) due to drying.

The binder fiber (B) in the present invention may be a core-sheath type or bonded type composite fiber in which other fiber-forming components are bonded, as described above, in addition to fibers consisting of such a thermal adhesive component alone. . In this case, the eccentric core-sheath type or bonded type develops crimp due to heat treatment during thermal bonding, resulting in spiral crimp, resulting in spring-like elasticity. As a result, the movement of the composite fiber (8) within the fiber structure becomes easier, and the crimped form changes during water absorption and drying, in other words, the advantage is that the fiber structure becomes more sophisticated and changes in area. be.

The fiber-forming component constituting such composite binder fibers is not particularly limited as long as it has a melting point at least 20°C higher than the melting point of the thermal adhesive component.2 Usually, polyester, polyamide, polyolefin, etc. are used, and the composite The ratio is 20 to 70% thermal adhesive component.
It is set so that it is within the range of .

Further, the cross-sectional shape of the composite binder fiber may be either a core-sheath type or a laminated type as described above, for example, as shown in FIG.
Hollow core-sheath type composite fibers as shown in b), side-by-side type composite fibers as shown in Figure 1(a), eccentric type composite fibers as shown in Figure 1(C), hollow side-by-side type composite fibers as shown in Figure 7, and can take any form such as a solid core-sheath type conjugate fiber or a modified hollow conjugate fiber.

In addition, since the hollow core-sheath type composite binder fiber has a hollow part, the bulkiness is also improved, and from this point of view, the ratio of the hollow part is 3.
It is preferable to set it to 30%. Further, the shape of the hollow portion may be arbitrary, such as a circular shape or a polygonal irregular shape, and there may be a plurality of hollow portions, such as 2 to 4 hollow portions.

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

The fineness of the binder fiber (B) is preferably 0.5 to 20 deniers from the viewpoint of card passability during nonwoven fabric production, paper making properties, etc. The number of crimps varies slightly depending on the application, for example, for paper making, the number of crimps is 0 to 20/25 mm.
For dry non-woven fabrics and clothing, the number of crimp is 6 to 4.
0/25mm is suitable.

In addition, each component of the binder fiber (B) includes a matting agent and a flame retardant within a range that does not impede the object of the present invention.

Any additives such as deodorants and ultraviolet absorbers can be added.

The fiber structure of the present invention has the above composite fiber (A) of 50 to 95
It is important that the weight percent is thermally adhesively fixed by 50 to 5 weight percent of the binder fiber (B).

If the amount of the binder fiber (B) exceeds 50% by weight, it is not preferable because the number of thermal bonding fixing points of the composite fiber (^) increases and the change in bulk and area due to water absorption and drying of the fiber structure becomes small. . On the other hand, if it is less than 5% by weight, the number of thermal bonding points will be too small, resulting in less change in the volume and area of the fiber structure due to water absorption and drying, and the possibility of the fiber structure being cut by external force. This is not desirable as it may become lump-like.

In addition, the basis weight of the fiber structure is 5 g/d or more, preferably 1
It is necessary to set it to 0 g/d or more. If it is less than this range, the amount of the conjugate fiber (^) used will be small, and changes in the volume and area of the fibrous structure due to water absorption and drying will become small, which is not preferable.

Furthermore, in order to facilitate the crimping form change due to water absorption and drying of the composite fiber (A) and increase the volume and area change of the fiber structure, the volume of the fiber structure must be 10 n/g or more. . When the bulk is less than this range, composite fiber (A)
This is undesirable because the binding of the fiber structure becomes stronger, and the change in volume and area of the fiber structure becomes smaller.

Further, the fiber structure of the present invention needs to have an elevation of 5% or more after being treated under the following water absorption conditions and drying conditions for practical purposes.

Drying condition 2: Dry for 1 hour at 60°C Water absorption condition: 2 hours at 30°C with relative humidity 90% Moisture absorption If this elevation is less than 5%, the bulk and area change due to water absorption and drying of the fiber structure will not occur. As a result, changes in breathability, heat retention, filterability, texture, etc. are insufficient for practical purposes. 5%
If the content is above 20%, these properties will be good, but if the content is 20% or more, the changes in the above properties will become noticeable, which is more preferable.

The fiber #J structure of the present invention may be used with other fibers, such as natural fibers such as cotton, wool, and wood pulp, and ordinary synthetic fibers such as polyester, nylon, and polypropylene, as long as they do not impair the purpose of the present invention. Fibers etc. may also be used together. Although the amount varies depending on the type of fiber used in combination, the amount of the composite 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 fiber structure of the present invention described in detail above is partially thermally adhesively fixed by binder fibers, but composite fibers (A
) has ample space to freely change its shape. Therefore, as the crimp form of the composite fiber (^) changes due to water absorption and drying,
The morphology of the fiber structure changes reversibly.

For example, (Case 1) the number of crimps is 20/25 in the dry state.
++un, when using a composite fiber (A) that changes to 7/25 in the water absorption state, the apparent fiber length in the water absorption state increases, so the bulk of the fiber structure increases, and the area also increases at the same time. Additionally, because there are fewer crimps, breathability is increased and the texture is softer.

On the other hand, (Case 2) the number of crimps in the dry state is 14/25
n++n, 60/25ram composite fibers in water absorption state (
When A) is used, the apparent fiber length in the water-absorbed state becomes shorter, the bulk density of the fiber structure becomes higher, and the area becomes smaller at the same time. In addition, as the number of crimps increases, the breathability decreases, improving heat retention and filtering properties, but the texture becomes stiffer.

The fiber structures in (Case 1) and (Case 2) each have the above-mentioned characteristics, so they can be selected and used appropriately depending on the purpose of use. It is suitable for use in futons, covering materials for medical or sanitary materials, summer underwear, etc., and the -blade diameter is suitable for uses such as batting in cold-weather clothing, winter futons, etc.

(Effects of the Invention) Compared to conventional fiber structures, the fiber structure of the present invention has a larger change in properties and area due to water absorption and drying, and the shape of the fiber structure hardly changes even after repeated water absorption and drying. It has good morphological stability. It also has excellent properties such as good durability against external forces without tearing or dumping even when subjected to severe external forces.

Furthermore, since it is fixed by thermal adhesive, it has the characteristics that there is little shedding of fuzz and high breaking strength, and since the composite fiber (8) has spiral crimp, it is soft and elastic.

Taking advantage of these advantages, the fiber structure of the present invention can be used as surface materials and cushion materials for diapers and napkins.

It is used alone or in a layered form (including layered with other materials) for civil engineering materials, oil absorbents, various felts, futon hard traps, filters, poultice base fabrics, etc.

8 In addition, in the field of wet-laid nonwoven fabrics, fiber structures are used that are thermally bonded at the temperature of a Yankee dryer in a paper machine (100 to 120°C). In order to improve the filtering properties of the nonwoven fabric, it may be used as a composite product in which a film or nonwoven fabric is laminated on paper.

It goes without saying that the uses listed here are merely illustrative of the main ones, and are not limited to the uses of the fiber structure of the present invention.

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

Examples 1-4. Comparative Examples 1 to 4 The (A-n+) component had an intrinsic viscosity [η] of 1.1 (
Melting point is 215° (measured in m-cresol solution at 30°C)
Nylon 6 of C and the intrinsic viscosity [η
] is 0.45 (measured with an O-chlorophenol solution at 25°C) and a melting point of 254°C is 3.5 mol% copolymerized polyethylene terephthalate with a 5-sodium sulfoisophthalic acid component of 50:50 in a lamination type. The weight ratio of the composite was 9. The nozzle shown in Figure 2 was melt-extruded at 275°C from a spinneret with 1200 holes, and the spinning speed was 1000 m/min.
An undrawn composite fiber having a hollow ratio of 10% and a fiber cross-sectional shape as shown in FIG. 1(B) was obtained by taking it off at n+in. Next, this undrawn conjugate fiber was drawn three times in a 65°C hot water bath, heat-treated for 10% limited shrinkage in a 95°C hot water bath, and then 8/25III11 crimps were applied using a push-crimping device. ,
The fibers were subjected to relaxation heat treatment at 140° C. for 30 minutes to develop latent crimp, and then cut into 51 fiber lengths. The fineness of the obtained composite fiber is 3 denier, the number of crimps after drying at 60'C for 1 hour is 20/25, and the number of crimps after being left in an atmosphere of 30°C relative temperature 90% for 2 hours is 7. /25m.

On the other hand, 3 has an intrinsic viscosity [η] of 0.85 (measured with an o-chlorophenol solution at 25°C) and a melting point of 120°C.
Polyhexamethylene terephthalate copolymerized with mol% of 5-sodium sulfoisophthalic acid and 15 mol% of isophthalic acid was melt-extruded at 200°C from a die with a pore diameter of 0.3 mmφ and 3500 holes, and the spinning speed was The undrawn fibers were drawn at 1000 m/Nn and had a circular fiber cross section.

Next, the undrawn fibers were stretched 3.8 times in a hot water bath at 65°C, crimped using a push-crimping device so that the number of crimps after relaxation heat treatment was 13/25+++m, and then stretched at 100°C. The fibers were subjected to a relaxation heat treatment for 30 minutes, and then cut into fibers of 32 mm length. The fineness of the obtained binder fiber was 3 denier.

The humidity of the composite fibers was adjusted to make the number of crimps 16/25, and binder fibers were mixed therein in the proportions shown in Table 2, defibrated, carded to form a web, and hot air circulated. Heat treated at 140°C for 2 minutes in a die heat treatment machine to create an adhesive web (nonwoven fabric) having the basis weight and bulkiness listed in Table 2,
Its water absorption, drying, and texture were evaluated.

In addition, the bulkiness is 5 g/d when 10 layers of nonwoven fabric are stacked.
Before and after compression was repeated 50 times at 1-minute intervals under a load of It was calculated from the thickness of the nonwoven fabric when no load was applied, and the roughening rate was calculated from the following formula.

Rating rate Bulky property when absorbing water - Bulky property when drying xloo (%) Bulky when dry The results are shown in Tables 1 and 2.

Example 5 In Example 1, the undrawn composite fibers were stretched three times in a 65°C hot water bath, subjected to a 10% limited shrinkage heat treatment in a 95°C hot water bath, then subjected to tension heat treatment at 180°C for 8 seconds, and then pressed. After applying crimps using a crimping machine, a relaxation heat treatment was performed at 140°C for 30 minutes to develop latent crimps of 14 crimps/25 cities,
Next, a web was prepared in the same manner as in Example 1, except that the fibers were cut to a fiber length of 511III, and evaluated in the same manner as in Example 1. The results are also shown in Table 2.

Example 6. Comparative Example 5 In Example 1, the (^-8) component of the composite fiber has an intrinsic viscosity [η] of 0.40 and a melting point of 252°C.
When polyethylene terephthalate copolymerized with 5 mol% of 5-sodium sulfoisophthalate is used (Example 6), the intrinsic viscosity [η] is 0.50 and the melting point is 257°C.
In the case of using polyethylene terephthalate copolymerized with 1 mol% of 5-sodium sulfoisophthalate (Comparative Example 5), a web was prepared in the same manner as in Example 1 except for that. It was evaluated as follows.

The results are also shown in Table 2.

The nonwoven fabric of Example 6 had a large degree of flattening due to drying and water absorption, and had a soft texture and good shape retention (settling resistance). The evaluation was discontinued because nylon 6 (A-n+) and copolymerized polyethylene terephthalate (A-s) were partially peeled off, the crimped form change due to dry water absorption was small, and the resulting web had little deformation. .

Example 7 In Example 1, the binder fiber (B) was combined with polyethylene terephthalate of 3 [η] 0.64 and the same copolymerized polyhexamethylene terephthalate polyester used for the binder fiber of Example 1 at a composite ratio of 50.
It has a hollow side-by-side type cross section as shown in Fig. 7, which is composite-spun at a ratio of 150 (vessel ratio), has a fineness of 3 denier, and has a crimp count of 2.
Composite binder fibers of 3 pieces/25 mm (three-dimensional crimped) and fiber length of 32 nun were used, and the composite fibers of Example 1 were used as composite fibers (A) at a mixing ratio of 80/20 (A/
A nonwoven fabric was obtained in the same manner as in Example 1 except for B).

The results are shown in Tables 1 and 2.

Compared to Example 1, although the rate of gradation was slightly lower, good results were obtained.

Example 8 In Example 7, 5-sodium sulfoisophthalic acid and isophthalic acid were added in an amount of 5 mol % and 40 mol %, respectively, based on the terephthalic acid component as the heat-adhesive component of the binder fiber (B).
, copolymerized with 40 mol% of tetramethylene glycol,
A nonwoven fabric was obtained in the same manner as in Example 7 except that 4-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 thermal adhesive component used in the binder fiber FB) was somewhat hard, the obtained nonwoven fabric was slightly harder than that of Example 7, but this was no problem in practical use.

Example 9 Example 8 except that a composite fiber having a fiber cross-sectional shape shown in FIG. 1(a) was used as the composite fiber (A).
A nonwoven fabric was obtained and evaluated in the same manner as above.

The results are shown in Tables 1 and 2.

5 The polymers used in Table 1 are as follows (a) ~
5-sodium sulfoisophthalic acid 3.5 mol% copolymerized polyethylene terephthalate (a) 2 5 mol% copolymerized polyethylene terephthalate (2): 1 mol% copolymerized polyethylene terephthalate (1): 3 mol% and isophthalic acid 15 mol% copolymerized polyhexamethylene terephthalate (O): 5-su1-
Lithium sulpoisophthalic acid 3 mol%, isophthalic acid 40
mol%, and tetramethylene glycol 40 mol% copolymerized polyethylene terephthalate (force): Polyethylene terephthalate However, the amount of copolymerization is mol% based on the terephthalic acid component.

7 No. table 8

[Brief explanation of drawings]

Figure 1 and Figures 4 to 7 are examples showing cross-sectional views of the composite fiber (8) used in the present invention, and Figure 2 shows the composite fiber (8) obtained in Figure 1 (b). This figure shows an example of a spinning hole for this purpose. In addition, Figure 3 shows Figures 1 (a) and (
FIG. 3 is a cross-sectional view showing an example of a spinning nozzle polymer inlet portion when manufacturing the composite fiber (^) shown in C). A-s + Ingredient A- with small expansion and contraction changes due to water absorption and drying
rm: Center of gravity of component GA28 to 3 components with large expansion and contraction changes due to water absorption and drying GB: Center of gravity of component A-111! . ~8 Double center distance N: Spinning hole S Nislit H: Hollow part

Claims (4)

[Claims] 1. Binder fiber (B) 50 to 95% by weight of composite fibers (A) bonded in a laminated or eccentric manner that reversibly change the crimp form with changes in water absorption and drying.
A fiber structure thermally bonded with 0 to 5% by weight, the structure has a basis weight of 5g/m^2 or more and a bulk of 10c.
m^3/g or more, and has a volume change of 5% or more when measured under the following water absorption/drying conditions. (Drying conditions: 1 hour drying at 60℃, water absorption conditions: 2 hours moisture absorption at 30℃ 90% relative humidity) 2. Composite fiber (A) contains polyamide and 5-sodium sulfoisophthalic acid component in an amount of 2 to 7 mol% based on the acid component.
2. The fiber structure according to claim 1, which is a composite fiber comprising copolymerized modified polyester. 3. The thermal adhesive component of the binder fiber (B) contains 2 to 7 mol% of 5-sodium sulfoisophthalic acid component based on the acid component, and 50 mol% or more of tetramethylene glycol and/or hexanediol based on the total glycol component. The fibrous structure according to claim 1, which is a polymerized modified polyester having a melting point of 80 to 230°C. 4. The fiber structure according to claim 1 or 2, wherein the composite fiber (A) has a hollow cross section.