WO2023008500A1

WO2023008500A1 - Composite fiber bundle and fiber product

Info

Publication number: WO2023008500A1
Application number: PCT/JP2022/029025
Authority: WO
Inventors: 知彦松浦; 正人増田; 慎也川原; 康二郎稲田
Original assignee: 東レ株式会社
Priority date: 2021-07-27
Filing date: 2022-07-27
Publication date: 2023-02-02
Also published as: JPWO2023008500A1; CN117716076A; KR20240034772A

Abstract

The present invention pertains to a composite fiber bundle characterized by being constituted by composite fibers comprising at least two types of polymers having different melting points, and by being such that the variation coefficient CV for the value of the ((distance between polymer centers of gravity)/(fiber diameter)) among the composite fibers is 5-30%.

Description

Composite fiber bundles and textile products

The present invention relates to a composite fiber bundle suitable for clothing textiles and a fiber product containing the composite fiber bundle.

Synthetic fibers such as polyester and polyamide have excellent mechanical properties and dimensional stability, so they are widely used for both clothing and non-clothing applications. However, in recent years, when people's lives have diversified and people have come to seek a better life, there is a demand for fibers with higher tactile sensations and functions.

As a fiber with such a higher touch and function, a method of using a composite fiber with a side-by-side cross section that is made by bonding different polymers has been proposed.

This side-by-side type conjugate fiber is intended to give a texture such as a moderate feeling of resilience and swelling by expressing crimps due to the difference in heat shrinkage between polymers. When the composite fiber bundles are used to make textiles, all the composite fibers express the same crimped form, so that the crimp phases are aligned, and there are cases where the texture lacks a feeling of swelling and is flat. rice field.

On the other hand, textiles for clothing that come into contact with the human skin are often required to be comfortable to wear, and there is a strong demand for fibers that have a texture that is directly linked to human comfort, like natural fibers. The texture and functions of natural materials such as wool, cotton, and silk are extremely well-balanced, and the complex appearance and texture woven by these materials are attractive and luxurious to humans. Because I feel

In order to solve the problem that the crimp phase between the composite fibers in the synthetic fibers is uniform and the texture lacks a feeling of fullness, the composite fibers that make up the composite fiber bundle are devised one by one. Various techniques have been proposed to make the tactile feel and texture of natural materials more complex and bring them closer to the unique tactile feel and texture found in natural materials.

In Patent Document 1, in a conjugate fiber bundle composed of conjugate fibers in which polyethylene terephthalate (PET) having different viscosities are conjugated side-by-side, the conjugate ratio is changed between the conjugate fibers to reduce the variation in the curvature of the polymer interface. It is disclosed that the crimps are formed independently without meshing due to the difference in crimp shape between the conjugate fibers depending on the conjugate ratio.

A conjugate fiber bundle composed of such conjugate fibers expresses voids between the conjugate fibers according to the difference in crimp configuration, so when the conjugate fiber bundle is used as a textile, it has a bulging texture.

Further, in Patent Document 2, a conjugated fiber in which polyethylene terephthalate (PET) having different viscosities is conjugated in a side-by-side type is used as a modified cross section, and three or more types of conjugates having different states of the conjugated bonding surfaces, which are the bonding surfaces between the conjugated components, are used. It discloses that by forming a conjugate fiber bundle composed of fiber groups, each conjugate fiber group has a different flexural rigidity, and conjugate fiber groups with different crimp development properties can be obtained.

By utilizing such composite fiber bundles, it is possible to obtain textiles that combine natural fiber-like swelling and bulkiness with stretchability and resilience.

Japanese Patent Application Laid-Open No. 2000-212838 Japanese Patent Application Laid-Open No. 2001-355132

As in Patent Document 1, by changing the conjugate ratio between the conjugate fibers that make up the conjugate fiber bundle to develop variations in the curvature of the polymer interface, crimp morphological differences between the conjugate fibers may appear. .

However, in Patent Document 1, the change in the conjugate ratio, which can be used as a means for changing the crimp configuration of each conjugate fiber, is substantially in the range of 40:60 to 60:40 in order to maintain spinning stability. However, the difference in crimp shape change obtained here is small, and naturally the texture obtained is sometimes monotonous.

In addition, as in Patent Document 2, by forming a composite fiber bundle composed of three or more types of composite fiber groups having different states of composite joint surfaces, each composite fiber group has a different bending rigidity, and crimp development is achieved. may be different composite fiber groups.

However, the conjugate fiber described in Patent Document 2 has a substantially multilobed cross section, and the distance between the polymer centers of gravity required for crimp development is naturally short, so the crimp development force is low. In some cases, the bulge and resilience required for comfortable clothing were insufficient.

Therefore, the object of the present invention is to solve the above-described problems of the prior art, and to control the crimped form of each conjugate fiber that constitutes the conjugate fiber bundle, so that in addition to a smooth touch, an appropriate resilience is obtained. To provide a conjugate fiber bundle suitable for obtaining a textile for clothing having a feeling and a puffy texture and excellent wearing comfort.

The object of the present invention is achieved by the following means. i.e.
(1) A conjugate fiber bundle composed of conjugate fibers composed of at least two kinds of polymers having different melting points, wherein the variation coefficient CV of the value of (distance between polymer centers of gravity/fiber diameter) between the conjugate fibers is 5 to 30. %,
(2) The conjugate fiber bundle according to (1), wherein the difference between the maximum and minimum flatness values of the conjugate fibers is less than 0.5;
(3) The conjugate fiber bundle according to (1) or (2), characterized in that the average value of flatness between the conjugate fibers is 1.2 to 3.0;
(4) The conjugate fiber bundle according to any one of (1) to (3), wherein the surface layer of the conjugate fiber is covered with one type of polymer;
(5) A textile product partially containing the composite fiber bundle according to any one of (1) to (4) above,
is.

The conjugate fiber bundle of the present invention has the features described above, so that the crimped form of each conjugate fiber constituting the conjugate fiber bundle is precisely controlled. Therefore, by using the conjugate fiber bundle of the present invention, it is possible to obtain a textile for clothing that is excellent in wearing comfort and has a moderate resilience and a puffy texture in addition to a dry feel.

(a), (b), and (c) of FIG. 1 are schematic diagrams showing an example of the cross-sectional structure of the composite fibers that constitute the composite fiber bundle of the present embodiment. FIGS. 2(a) and 2(b) are schematic diagrams showing an example of the cross-sectional structure of the conjugate fibers forming the conjugate fiber bundle of the present embodiment. FIG. 3 is a schematic diagram showing an example of a cross-sectional structure of conjugate fibers forming a conventional conjugate fiber bundle. FIG. 4 is a schematic diagram showing an example of the cross-sectional structure of each composite fiber that constitutes the composite fiber bundle of the present embodiment. FIG. 5 is a diagram for understanding the coefficient of variation CV of the value of (distance between center of gravity of polymer/fiber diameter) between conjugate fibers constituting the conjugate fiber bundle of the present embodiment. means the top, bottom, left, and right sides of . FIG. 6 is a schematic diagram showing an example of the crimped form of the conjugate fibers that constitute the conjugate fiber bundle of the present embodiment. FIG. 7 is a cross-sectional view for explaining the manufacturing method of the conjugate fibers forming the conjugate fiber bundle of the present embodiment.

Hereinafter, the present invention will be described in detail together with preferred embodiments.
An analysis of cotton, which is widely used as a natural material with a smooth feel and a soft, fluffy texture, reveals that each fiber has a different crimp pattern. By bundling, complex voids and irregularities are formed when it is made into textiles, and it is thought that the unique tactile sensation and texture are achieved.

The present inventors have made intensive studies to realize complex voids and irregularities like natural materials with synthetic fibers, and have found that in a conjugate fiber bundle composed of conjugate fibers composed of at least two types of polymers having different melting points, the conjugate By controlling the distance between the polymer centers of gravity of each fiber and aligning the crimp phase appropriately, we discovered that it was possible to form complex voids and irregularities that were difficult to obtain with conventional synthetic fibers.

That is, when all the conjugate fibers constituting the conjugate fiber bundle express the same crimped form, the conjugate fiber bundle is converged with the same crimp phase, and the gap between the conjugate fibers becomes smaller. , The texture when used as a textile may be flat without a feeling of swelling.

On the other hand, when the conjugate fibers constituting the conjugate fiber bundle express different crimped forms, gaps tend to be formed between the conjugate fibers due to the shift in the crimp phase of the conjugate fibers. However, the morphology of the conjugate fiber bundle does not change, and the size of the voids formed between the conjugate fibers becomes uniform, so that when the conjugate fiber bundle is used as a textile, the appearance and texture may be monotonous. .

On the other hand, if the crimp expression of the composite fibers constituting the composite fiber bundle is changed, if the crimp phase of the composite fibers is controlled to be partially aligned, when the composite fiber bundle is used as a textile Furthermore, in addition to the fine voids inherent in the conjugate fiber bundle, there are areas where the crimp phases are aligned and those where the crimp phases are not aligned between adjacent conjugate fibers. As a result, complex voids are created between the composite fibers, and complex irregularities not found in conventional composite fiber bundles are created. can be expressed.

The present invention is constructed based on this idea, and specifically, a conjugate fiber bundle composed of conjugate fibers composed of at least two kinds of polymers having different melting points, and the distance between the centers of gravity of the polymers (distance between the centers of gravity of the polymers /fiber diameter) is 5 to 30%.

The conjugate fiber bundle in the present embodiment is a conjugate fiber bundle in which, for example, 20 or more conjugate fibers made of at least two types of polymers are bundled. say.

A thermoplastic polymer is preferable as the polymer used for the conjugate fibers constituting the conjugate fiber bundle of the present embodiment because of its excellent workability. Preferred thermoplastic polymers are, for example, polyester-based, polyethylene-based, polypropylene-based, polystyrene-based, polyamide-based, polycarbonate-based, polymethyl methacrylate-based, polyphenylene sulfide-based polymers, and copolymers thereof. From the viewpoint that a particularly high interfacial affinity can be imparted and a fiber having no abnormalities in the composite cross section can be obtained, all the thermoplastic polymers used in the composite fiber are preferably the same polymer group and copolymers thereof.

In addition, various additives such as inorganic substances such as titanium oxide, silica, and barium oxide, carbon black, colorants such as dyes and pigments, flame retardants, fluorescent brighteners, antioxidants, and ultraviolet absorbers are included in the polymer. You can stay.

Among these, it is preferable to include titanium oxide in the polymer. By including titanium oxide in the polymer, the titanium oxide on the surface of the composite fiber diffusely reflects light, which only improves the appearance quality, such as suppressing the appearance unevenness (glare) caused by the increase or decrease in reflection depending on the angle of incidence of light. Not only that, the titanium oxide inside the composite fiber also provides functionality such as anti-see-through and UV shielding. The content of titanium oxide in the polymer is preferably 1.0 wt % or more in order to sufficiently obtain the above effects. In addition, the content of titanium oxide is preferably 10.0 wt % or less, because an increase in diffuse reflection of light by titanium oxide may lead to a decrease in color developability.

The conjugate fibers constituting the conjugate fiber bundle of the present embodiment need to be made of at least two types of polymers with different melting points in order to control the crimped form.

If polymers with different melting points are arranged at different centers of gravity in the cross section of the conjugated fiber, the conjugated fiber is greatly curved toward the low-melting polymer side where the shrinkage is high after the heat treatment. Shortened forms can be expressed. Furthermore, by controlling the distance between the centers of gravity of the polymers, it is possible to express any crimped form, thereby achieving the control of the crimp phase, which is the object of the present invention.

Polymers with different melting points in the present embodiment include a group of melt-moldable thermoplastic polymers such as polyesters, polyethylenes, polypropylenes, polystyrenes, polyamides, polycarbonates, polymethyl methacrylates, and polyphenylene sulfides, and their A combination of polymers having different melting points of 10°C or more among copolymers.

In the conjugate fibers constituting the conjugate fiber bundle of the present embodiment, the purpose is to express a crimped form by the difference in shrinkage of polymers with different melting points. is preferably a low melting point polymer and the other is a low shrinkage high melting point polymer.

In particular, from the viewpoint of suppressing peeling and imparting stability in advanced processing and durability in use to textiles, a combination of polymers such as ester-bonded polyesters and amide-bonded polyamides existing in the main chain It is more preferable to select from among the same group of polymers in which the bonds that bind are identical.

Combinations of low-melting polymers and high-melting polymers in the same polymer group include, for example, polyester-based copolymer polyethylene terephthalate/polyethylene terephthalate, polypropylene terephthalate/polyethylene terephthalate, polybutylene terephthalate/polyethylene terephthalate, and thermoplastic polyurethane. /polyethylene terephthalate, polyester elastomer/polyethylene terephthalate, polyester elastomer/polybutylene terephthalate, nylon 66/nylon 610, nylon 6-nylon 66 copolymer/nylon 6 or 610, PEG copolymer nylon 6/nylon 6 as polyamide or 610, thermoplastic polyurethane/nylon 6 or 610, polyolefins such as ethylene-propylene rubber finely dispersed polypropylene/polypropylene, and propylene-α-olefin copolymer/polypropylene.

Among these, polymers with different melting points are used together from the viewpoint that when the conjugate fiber bundle is made into textiles, a moderate resilience can be obtained from high bending recovery and good color development can be obtained when dyed. A polymerized polyethylene terephthalate/polyethylene terephthalate combination is particularly preferred.

Examples of copolymerization components in copolymerized polyethylene terephthalate include succinic acid, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, phthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, and the like. is mentioned. Among these, it is preferable to use polyethylene terephthalate copolymerized with 5 to 15 mol % of isophthalic acid from the viewpoint of maximizing the difference in shrinkage from polyethylene terephthalate.

In addition, while attention is focused on environmental problems, using plant-derived biopolymers and recycled polymers in this embodiment is also suitable from the viewpoint of reducing environmental impact. Therefore, as the polymer used in the present embodiment described above, a recycled polymer recycled by any of chemical recycling, material recycling, and thermal recycling can be used.

Even when biopolymers or recycled polymers are used, polyethylene terephthalate-based resins can make the features of the present invention remarkable as their polymer characteristics. Therefore, as described above, recycled polyethylene terephthalate is preferably used as the polymer used in the present embodiment from the viewpoint of obtaining an appropriate resilience from high bending recovery and obtaining good color development when dyed. can be used.

The cross section of the composite fiber of the present embodiment is preferably a composite section in which polymers with different melting points are arranged so that their centers of gravity are different. Examples of such a composite cross section include a side-by-side type as shown in FIG. 1(a) and an eccentric core-sheath type as shown in FIG. 1(b). be done.

Further, in the present embodiment, the surface layer of the composite fiber is preferably covered with one type of polymer. Since the surface layer of the conjugate fiber is covered with one type of polymer, even if a polymer with low heat resistance and abrasion resistance is used as one component of the conjugate fiber, the fiber does not peel off at the interface due to friction or impact. Good properties can be retained.

In addition, when the conjugate fiber bundle of the present embodiment is produced, if melts of polymers with a large melting point difference are spun from the die as a composite flow, the high melting point polymer curves toward the low melting point polymer side due to the cooling difference after ejection. Yarn bending occurs, which causes yarn breakage by contacting the spinneret or interfering with the composite flow spun from another location. However, by covering the surface layer of the conjugate fiber with one type of polymer, the cooling difference can be alleviated and yarn bending can be suppressed. Become.

Examples of one type of polymer covering the surface layer of the conjugate fiber include polyethylene terephthalate, copolymerized polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate as polyesters, nylon 6, nylon 66 and nylon 610 as polyamides, and polypropylene as polyolefins. is mentioned. Among these, polyethylene terephthalate or copolymerized polyethylene terephthalate is preferably used to cover the surface layer of the conjugate fiber from the viewpoint of excellent heat resistance and color development.

In addition, the thickness of one type of polymer covering the surface layer of the conjugate fiber can be adjusted as appropriate. is preferably 0.01 to 0.1. Within this range, even if the composite fiber or textile is subjected to friction or impact, whitening or fluffing does not occur, and the yarn processing stability and textile quality can be maintained. Furthermore, when the S/D is 0.02 to 0.08, the center of gravity of the high-melting polymer and the low-melting polymer are separated, and the crimp due to the difference in shrinkage can be maximized, so it is mentioned as a more preferable range. .

The ratio S/D between the minimum thickness S of the polymer covering the surface layer of the conjugate fiber and the fiber diameter D in the present embodiment is obtained by embedding the conjugate fiber bundle in an embedding agent such as an epoxy resin, and then It is obtained by taking an image with a transmission electron microscope (TEM) at a magnification that allows observation of 10 or more composite fibers, and observing the cross section of the composite. At this time, by applying metal dyeing, a difference in dyeing between polymers can be obtained, so that the contrast of the joints of the composite cross section can be clarified.

Furthermore, when the composite cross section of the photographed image is an eccentric core-sheath type cross section as shown in FIG. Determine the minimum thickness of the polymer covering the surface layer of the fiber in μm. A value obtained by dividing the value of the obtained minimum thickness S by the value of the fiber diameter D obtained by measuring the area of each conjugate fiber and measuring the diameter obtained in terms of a perfect circle in units of μm to the first decimal place. is calculated, and the average value is rounded to the third decimal place to obtain the ratio S/D between the minimum thickness S of the polymer covering the surface layer of the composite fiber and the fiber diameter D.

The area ratio of the low-melting polymer and the high-melting polymer in the composite cross-section of the composite fiber constituting the composite fiber bundle of the present embodiment is 70/30 to 30/70. A range is preferred, and 60/40 to 40/60 is more preferred. Within this range, the crimped form due to the difference in shrinkage of the polymer can be sufficiently developed without being affected by the hardening of the texture that occurs when the low-melting-point polymer undergoes high shrinkage due to heat treatment.

In the present embodiment, by partially aligning the crimp phases between the conjugate fibers constituting the conjugate fiber bundle, the portions where the crimp phases are aligned and the portions where the crimp phases are not aligned are Since there is a difference in voids, unevenness can be formed on the surface when the composite fiber bundle is used as a textile.

As a requirement for forming the complex voids between the conjugate fibers and the irregularities on the textile surface, which are the features of the present invention, the coefficient of variation CV of the value of (distance between the center of gravity of the polymer / fiber diameter) between the conjugate fibers is 5 ~30% is important.

The coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) referred to in this embodiment can be calculated by the following method.

First, in a textile made of a bundle of conjugate fibers, the cross section of the textile perpendicular to the thickness direction of the textile and the fiber axis direction of the conjugate fiber is measured using a scanning electron microscope (SEM) as a magnification that allows observation of 20 or more conjugate fibers. Take an image. By analyzing one composite fiber randomly extracted from the same image from the photographed image, the area of the composite fiber is measured, and the diameter obtained by converting to a perfect circle is measured in μm to the first decimal place. do. The obtained value is defined as the fiber diameter (μm) of the composite fiber.

Next, for the same conjugate fiber as above, the length of a straight line connecting the respective centers of gravity (Gx, Gy) of the low melting point polymer x and the high melting point polymer y in the cross section of the conjugate fiber as shown in FIG. Measure to the first decimal place in units of μm. The obtained value is taken as the polymer center-to-center distance (μm).

For the fiber diameter and the polymer center-of-gravity distance obtained above, calculate the simple number average of the ratio (polymer center-of-gravity distance/fiber diameter), and calculate the value rounded to the first decimal place (polymer center-of-gravity distance/fiber diameter ).

This evaluation is performed on 20 composite fibers ((1) to (20) in FIG. 5) randomly extracted from the same image as above, and the standard deviation and average value are obtained. Calculate the value by dividing by and multiplying by 100, and round off to the nearest whole number. The obtained value is defined as the coefficient of variation CV (%) of the value of (distance between polymer centers of gravity/fiber diameter).

In the conjugate fibers constituting the conjugate fiber bundle of the present embodiment, the crimp form can be controlled by the distance between the polymer centers of gravity and the fiber diameter. A shortened form can be expressed. That is, the crimp development force is represented by (distance between polymer centers of gravity/fiber diameter). It is possible to control the formation of voids and irregularities on the textile surface.

That is, in the present embodiment, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) between conjugate fibers constituting the conjugate fiber bundle is 5% or more. By setting the coefficient of variation CV in the above range, the crimp phase is partially aligned, so unevenness appears on the surface of the textile, and when the surface is touched, the texture is smooth due to the large frictional variation. is obtained. In addition, complex voids are created between the conjugate fibers, and a texture with a moderate repulsive feeling and an effect of suppressing uneven appearance (glitter) due to diffused reflection of light can be realized.

Furthermore, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) is more preferably in the range of 10 to 20%, more preferably in the range of 15 to 20%. When the coefficient of variation CV is within the above range, when the composite fiber bundle is used as a textile, the pitch of the irregularities on the surface of the textile becomes finer, and the dry feel is conspicuous. Furthermore, since the voids between the conjugate fibers increase, when the conjugate fiber bundle is used as a textile, the apparent density is lowered, and an effect of improving swelling is also added.

On the other hand, if the coefficient of variation CV becomes too large, the irregularities appearing on the surface of the textile become finer and the frictional fluctuation becomes smaller, resulting in a monotonous texture. Therefore, the coefficient of variation CV is 30% or less.

In the conjugate fibers constituting the conjugate fiber bundle of the present embodiment, as a method of controlling (distance between polymer centers of gravity/fiber diameter), a method of changing the cross-sectional shape and conjugate ratio of the conjugate fibers for each conjugate fiber is conceivable. From the viewpoint of the control of the crimp phase alignment and the spinning stability, the cross-sectional shape of the composite fibers constituting the composite fiber bundle is flattened, and the difference between the maximum value and the minimum value of the flatness between the composite fibers is set to 0.5. A method of less than 5 is preferred. Here, the term "flat" means an elongated shape in a plan view, and specifically, the "flatness" of the cross section of the conjugate fiber described later is 1.1 or more.

If the cross-sectional shape of the conjugate fiber is flat (flat cross section), when polymers with different melting points are joined in the longitudinal direction of the flat cross section as shown in FIG. In the case of bonding in the direction of the minor axis of the flat cross section as shown in FIG. 2B, the distance between the polymer centers of gravity is minimized. In this way, by making the cross-sectional shape of the conjugate fiber flat, it is possible to control the value of (distance between polymer centers of gravity/fiber diameter) by changing the direction of the joint surface of the conjugate fiber.

Therefore, it is preferable that the difference between the maximum flatness value and the minimum value of the flatness between the conjugate fibers is less than 0.5. is more preferable. When the conjugate fibers have the above structure, the crimp phase between the conjugate fibers becomes easier to partially align, and the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) can be easily set within the desired range. Furthermore, compared to the case where the cross-sectional shape and conjugate ratio are changed for each conjugate fiber, yarn breakage due to yarn interference due to cooling spots is suppressed, and the spinning stability can be improved. More preferably, the difference between the maximum and minimum values of is less than 0.2.

In order to further develop the above effect, in the present embodiment, the average value of the flatness between the conjugate fibers is preferably 1.2 or more, more preferably 1.4 or more, and further preferably 1.6 or more. preferable. When the average value of the flatness between the conjugate fibers is 1.2 or more, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) can be brought closer to the optimum range. Furthermore, voids are formed between the conjugate fibers due to steric hindrance when the conjugate fibers having a flat cross section are crimped, and swelling is obtained when the conjugate fiber bundle is used as a textile.

As described above, from the viewpoint of controlling the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) and stably forming voids between conjugate fibers, the higher the average flatness value, the better. On the other hand, if the average value of the flatness is too high, the intensity of the light reflected on the surface of the composite fiber may increase, which may cause uneven appearance (glare). In addition, there is a possibility that the bending rigidity becomes higher than necessary due to the edged cross-sectional shape, thereby impairing the flexibility. Therefore, the average value of flatness in the present embodiment is preferably 3.0 or less, more preferably 2.5 or less, and even more preferably 2.0 or less.

In the present embodiment, the average flatness value and the difference between the maximum and minimum values of the flatness between the conjugate fibers are obtained by the following method.
First, a composite fiber bundle is embedded in an embedding agent such as an epoxy resin, and an image of the cross section of the fiber in the direction perpendicular to the fiber axis is observed with a scanning electron microscope (SEM) at a magnification of 10 or more composite fibers. to shoot. Next, one composite fiber randomly extracted from the photographed image is analyzed using image analysis software, and as shown in FIG. A straight line connecting two points (a1, a2) separated by a distance is taken as the major axis, and a straight line passing through the midpoint of the long axis and perpendicular to the long axis and the intersection point (b1, b2) of the outer circumference of the fiber is taken as the short straight line. As the axis, the value obtained by dividing the length of the long axis by the length of the short axis is calculated, and the obtained value is defined as the flatness. A simple numerical average of the results obtained by performing the same procedure on 10 conjugate fibers randomly extracted from the same image is calculated, and the value rounded to the second decimal place is used as the average flatness value. Also, among the conjugate fibers for which the flatness was obtained, the value obtained by subtracting the smallest value from the largest value is obtained, and the value is rounded off to the second decimal place as the difference between the maximum flatness value and the minimum flatness value.

The cross-sectional shape of the conjugate fibers constituting the conjugate fiber bundle of the present embodiment is flat as shown in FIG. 1(a), multilobed as shown in FIG. shape, gear shape, petal shape, star shape, and the like.

In this embodiment, it is preferable to combine conjugate fibers having a cross-sectional shape with three or more protrusions on the conjugate fiber surface. By combining conjugate fibers having a cross-sectional shape with three or more protrusions on the surface of the conjugate fiber, it is possible to suppress appearance unevenness (glare) due to diffuse reflection of light and improve water absorption due to fine voids between the conjugate fibers. . The number of protrusions is more preferably 5 or more, and even more preferably 8 or more.
However, if the number of protrusions becomes too large, the effect will gradually decrease, so the practical upper limit of the number of protrusions is 20, and 12 or less is more preferable.

The conjugate fibers constituting the conjugate fiber bundle of the present embodiment preferably have a crimped form with a number of crimp crests of 5 crimps/cm or more.

Here, the number of crimp crests is obtained by the following method.
First, the conjugate fiber is pulled out from the textile so as not to be plastically deformed, one end of the conjugate fiber is fixed, and a load of 1 mg / dtex is applied to the other end for 30 seconds or more. Mark any point where the distance between two points is 1 cm.
After that, the sample was fixed on a slide glass after adjustment so that the distance between the markings made in advance was 1 cm so as not to plastically deform the composite fiber, and the 1 cm marking of this sample could be observed with a digital microscope. Take an image at magnification. In the photographed image, when the composite fiber CF has a crimped form as shown in FIG. 6, the number of crimped peaks Cr present between the markings is obtained. A simple numerical average of the results obtained by performing this operation on 10 conjugate fibers is rounded off to the first decimal place to determine the number of crimp crests (crests/cm).

If the crimped form has a crimp number of crimps of 5 crests/cm or more, complex voids between the conjugate fibers and irregularities on the textile surface are formed by aligning the crimp phase between the conjugate fibers. be able to. More preferably, the number of crimp crests is 10 crests/cm or more. When the number of crimp crests is 10 crests/cm or more, not only is it possible to obtain the effect of improving swelling due to the increase in voids between conjugate fibers due to the excluded volume effect between conjugate fibers, but also the crimp form is fine. Stretchability is also given by becoming a spiral structure.

From the viewpoint of swelling and stretchability, it is preferable to increase the number of crimp ridges. As a result, when the composite fiber bundle is used as a textile, the texture may be monotonous. Therefore, the number of crimp crests in this embodiment is preferably 50 crests/cm or less, more preferably 40 crests/cm or less, and even more preferably 30 crests/cm or less.

It is preferable that the conjugate fibers constituting the conjugate fiber bundle of the present embodiment have a fiber diameter of 20 μm or less. Within this range, the diffused reflection of light from the conjugate fiber is increased, and not only is it possible to suppress the appearance unevenness (glare) when made into a textile, but it is also possible to obtain a sufficient sense of repulsion. As a result, it is suitable for use in clothing such as pants and shirts that require a firm texture.

Furthermore, it is more preferable to set the fiber diameter to 15 μm or less. By setting the fiber diameter to 15 μm or less, the flexibility of the composite fiber bundle is increased, and it can be suitably used for apparel such as innerwear and blouses that come in contact with the skin. More preferably, the fiber diameter is 12 μm or less.

In addition, from the viewpoint of suppressing deterioration in bending recovery and coloring properties, the fiber diameter is preferably 5 μm or more, more preferably 8 μm or more.

As described above, in the conjugate fiber bundle of the present embodiment, since there is a difference in gaps between adjacent conjugate fibers where the crimp phase is aligned and where the crimp phase is not aligned, complex voids and unevenness are created between the conjugate fibers. is formed.

Therefore, by including at least a part of the conjugate fiber bundle of the present embodiment in the textile product, in addition to being able to express a specific dry feel, the complex voids between the conjugate fibers provide an appropriate sense of resilience and swelling. A textile having a certain texture and excellent wearing comfort can be obtained.
Composite fiber bundles of the present embodiment can be used for general clothing such as jackets, skirts, pants, and underwear, as well as sports clothing and clothing materials. It can be suitably used for a wide variety of textile products such as interior goods, cosmetics, cosmetic masks, and health products.

An example of the method for producing the composite fiber bundle of the present embodiment will be described in detail below.
The method for spinning the composite fiber bundle of the present embodiment includes a melt spinning method for the purpose of producing multifilament and spun yarn, a solution spinning method such as a wet and dry-wet method, and a method suitable for obtaining a sheet-like fiber structure. It can be produced by a melt blow method, a spunbond method, or the like. Among these, from the viewpoint of obtaining a composite fiber bundle that can be applied to textiles with high productivity, it is preferable to use the melt spinning method to form a multifilament or a spun yarn.

In addition, in the melt spinning method, it is possible to manufacture by using a composite spinneret described later, and the spinning temperature at that time is the temperature at which the high melting point polymer and the high viscosity polymer mainly show fluidity among the polymer types used. It is preferable to Although the temperature at which this fluidity is exhibited varies depending on the molecular weight, if it is set between the melting point of the polymer and +60° C., stable production can be achieved.

The spinning speed is preferably about 500 to 6000 m/min, but it can be changed as appropriate depending on the physical properties of the polymer and the intended use of the composite fiber bundle. In particular, from the viewpoint of achieving high orientation and improving mechanical properties, it is more preferable to set the spinning speed to 500 to 4000 m/min and then draw. By setting the spinning speed to 500 to 4000 m/min, the uniaxial orientation of the conjugate fiber can be promoted.

When stretching, it is preferable to appropriately set the preheating temperature, using the softening temperature such as the glass transition temperature of the polymer as a guideline. The upper limit of the preheating temperature is preferably a temperature at which the conjugate fiber bundle is spontaneously stretched during the preheating process so that the yarn path is not disturbed. For example, in the case of PET having a glass transition temperature of around 70.degree.

In addition, the ejection amount per single hole in the spinneret for manufacturing the composite fiber bundle of the present embodiment is preferably 0.1 to 10 g/min/hole. By setting the discharge amount within the above range, stable production is possible. After being cooled and solidified, the discharged polymer flow is applied with oil and taken up by a roller having a specified peripheral speed. After that, it is drawn with a heating roller and, if necessary, further post-processed to form a conjugate fiber bundle in which desired conjugate fibers are bundled.

In addition, in the conjugate fibers constituting the conjugate fiber bundle of the present embodiment, it is preferable that the melt viscosity ratio of the conjugated polymer is less than 5.0. When the melt viscosity ratio is set within such a range, excessive crimping is suppressed, and the formation of complex voids and unevenness on the textile surface, which is the object of the present invention, is controlled by aligning the crimp phase between the conjugate fibers. becomes easier.

In addition, when the conjugate fiber bundle of the present embodiment is produced, if a polymer melt having a large difference in melt viscosity is spun from the spinneret as a composite flow, the difference in flow velocity due to the difference in the resistance received from the wall surface inside the spinneret hole causes The polymer on the low viscosity side pushes out the polymer on the high viscosity side, causing yarn bending. From the above point of view as well, the melt viscosity ratio of the composite polymer is preferably less than 5.0.

Also, it is preferable that the difference in the solubility parameter value is less than 2.0, because it is possible to stably form a composite polymer flow and obtain a composite fiber having a favorable composite cross section.

As the spinneret used when manufacturing the composite fiber bundle of the present embodiment, for example, the composite spinneret described in Japanese Patent Application Laid-Open No. 2011-208313 is suitably used.

The composite spinneret shown in FIG. 7 is incorporated into a spinning pack in a state in which roughly three types of members, namely a weighing plate 1, a distribution plate 2 and a discharge plate 3, are layered from the top, and used for spinning. Incidentally, FIG. 7 is an example using three types of polymers, A polymer, B polymer, and C polymer. Since it is difficult to combine three or more types of polymers with a conventional composite spinneret, a composite spinneret using fine flow channels as shown in FIG. It is preferable to use

In the spinneret member exemplified in FIG. 7, the metering plate 1 measures and flows the amount of polymer per each discharge hole and each distribution hole, and the distribution plate 2 controls the cross section of each conjugate fiber and its cross-sectional shape. 3 has the role of compressing and discharging the composite polymer stream formed by the distribution plate 2 .

At this time, in order to achieve a composite cross section in which all the composite fibers constituting the composite fiber bundle have a flat cross section and the joint surface direction is changed for each composite fiber, which is mentioned as a preferable range of the present embodiment, The flow of the composite polymer may be controlled such that the direction of the bonding surface of the polymer differs for each ejection hole in the distribution plate 2 while the ejection holes of the ejection plate 3 are flat. From the viewpoint of being able to control an arbitrary composite cross section for each discharge hole in this way, it is preferable to use a composite spinneret using fine flow channels as illustrated in FIG. 7 in this embodiment.

Also, in order to avoid complicating the explanation of the composite spinneret, although not shown in the drawings, the members stacked above the weighing plate 1 are formed with flow paths in accordance with the spinning machine and the spinning pack. Just do it. By designing the metering plate 1 according to the existing channel member, the existing spinning pack and its members can be used as they are. Therefore, it is not necessary to dedicate a spinning machine specifically for the spinneret.

Also, in practice, it is preferable to stack a plurality of flow path plates between the flow path and the measuring plate 1 or between the measuring plate 1 and the distribution plate 2 . The purpose of this is to provide a flow path through which the polymer is efficiently transported in the cross-sectional direction of the spinneret and the cross-sectional direction of the composite fiber, and to introduce the polymer into the distribution plate 2 . The composite polymer stream discharged from the discharge plate 3 is cooled and solidified in accordance with the above-described manufacturing method, then applied with an oil solution and taken up by a roller having a specified peripheral speed. After that, it is drawn with a heating roller and post-processed as necessary to form a conjugate fiber bundle in which desired conjugate fibers are bundled.

The post-processing referred to here is applied when producing a spun yarn composed of short fibers, and after drawing, crimping is applied using a crimper or the like, and then the fiber length is 20. It may be cut into short fibers of ˜120 mm and then subjected to known spinning processing techniques.

In addition, when manufacturing a multifilament made of long fibers, known yarn processing techniques such as false twisting and non-uniform drawing processing may be applied at the same time as drawing.

In particular, from the viewpoint that the crimped form can be changed to a non-uniform form and the texture and texture obtained can be complicated, non-uniform drawing processing is performed and the composite fiber is drawn at a draw ratio within a range not exceeding the natural draw ratio of the composite fiber. By processing, it is preferable to obtain thick and thin fibers in which stretched portions and unstretched portions appear randomly in the fiber axis direction (sick and thin). The non-uniform stretching process creates a difference in dyeability between the stretched and unstretched sections, which emphasizes the shade of the color, and when used as a textile, it can express the heathered tone of natural materials. .

As a method for non-uniform stretching, the stretching ratio is within the range of the lower limit of the natural stretching ratio x 1.2 times to the upper limit. Magnification may be determined according to the key.

In the case of applying false twisting, there is no particular limitation as long as it is a method commonly used for polyester, but in consideration of productivity, processing using a friction texturing machine using a disc or belt is used. preferably.

In order to stably produce the crimped yarn of the present invention by false twisting, it is preferable to control the crimp diameter of the crimped yarn by the number of actual twists of the yarn bundle in the twisting region.
That is, the number of false twists T (unit: times/m), which is the number of twists of the yarn bundle in the twisting region, is determined according to the total fineness Df (unit: dtex) of the yarn bundle after false twisting. It is preferable to set the false twisting conditions such as the rotation speed of the twisting mechanism and the processing speed so as to satisfy the following conditions.
20000/ ^{Df0.5≤T≤40000} / ^Df0.5

Here, the false twist number T is measured by the following method. That is, the yarn bundle running in the twisting area of the false twisting step is collected with a length of 50 cm or more so as not to untwist just before the twister. The false twist number T is obtained by attaching the collected yarn sample to a twist tester and measuring the number of twists by the method described in JIS L1013 (2010) 8.13. When the number of false twists satisfies the above conditions, the obtained yarn bundle can control a coarse crimp diameter of 300 μm or more, and can suppress deterioration of the textile surface quality such as grains and streaks.

Further, under the above false twisting conditions, in order to uniformly crimp the entire conjugate fibers constituting the conjugate fiber bundle and obtain the textured yarn of the present invention with good quality, it is necessary to adjust the draw ratio in the twisting region. good. The draw ratio referred to here is calculated as Vd/V0 using the peripheral speed V0 of the roller that supplies the yarn to the twisting region and the peripheral speed Vd of the roller installed immediately after the twisting mechanism. It is preferable to determine according to the characteristics of the yarn to be used.

When drawn yarn is used as the supply yarn, Vd/V0 may be 0.9 to 1.4 times, and when undrawn yarn is used as the supply yarn, Vd/V0 is 1.2 to 1.2. At 2.0 times, drawing may be performed at the same time as false twisting. By setting the draw ratio within such a range, uniform crimping can be imparted to the entire conjugate fibers forming the conjugate fiber bundle without causing excessive tension in the twisting region or slackening of the yarn bundle.

Furthermore, from the viewpoint of firmly fixing the crimp obtained in the twisting process, it is preferable to determine the false twisting temperature in the range of Tg + 50 to Tg + 150 ° C based on the Tg of the polymer on the high Tg side in the composite polymer.

The false twist temperature here means the temperature of the heater installed in the twisting area. By setting the false-twisting temperature within this range, it is possible to sufficiently fix the structure of the polymer that has been greatly twisted and deformed within the cross section of the conjugate fiber. Good quality textiles can be obtained. In order to fix the crimps obtained in the twisting step and not to impair the crimp development force obtained by polymer compositing, it is preferable to use a one-heater method in which a heater is arranged only in the twisting region.

Hereinafter, the composite fiber bundle of the present invention will be specifically described with reference to examples.
Examples and comparative examples were evaluated as follows.

A. Melt Viscosity of Polymer Chip-shaped polymer was adjusted to a moisture content of 200 ppm or less by a vacuum dryer, and the melt viscosity was measured by changing the strain rate stepwise by Toyo Seiki Capillograph. The measurement temperature was the same as the spinning temperature, the sample was placed in the heating ^furnace under a nitrogen atmosphere and the measurement was started in 5 minutes.

B. Melting point of polymer A chip-shaped polymer is made to have a moisture content of 200 ppm or less by a vacuum dryer, and about 5 mg is weighed and heated from 0 ° C. to 300 ° C. using a differential scanning calorimeter (DSC) Q2000 manufactured by TA Instruments. After the temperature was raised at a temperature rate of 16°C/min, the DSC measurement was performed after holding at 300°C for 5 minutes. The melting point was calculated from the melting peak observed during the heating process. The measurement was performed three times for each sample, and the average value was taken as the melting point. When multiple melting peaks were observed, the melting peak top on the highest temperature side was taken as the melting point.

C. The weight of a composite fiber bundle having a fineness of 100 m was measured, and the value multiplied by 100 was calculated. This operation was repeated 10 times, and the value obtained by rounding off the average value to the second decimal place was used as the fineness (dtex).

D. Flatness The conjugate fiber bundle is embedded in an embedding agent such as epoxy resin, and the cross section of the fiber in the direction perpendicular to the fiber axis is observed with a scanning electron microscope (SEM) manufactured by HITACHI as a magnification at which 10 or more conjugate fibers can be observed. I took the image. One composite fiber randomly extracted from the photographed image is analyzed using image analysis software, and as shown in FIG. A straight line connecting two distant points (a1, a2) is taken as the long axis, and a straight line passing through the midpoint of the long axis and perpendicular to the long axis is taken as the short axis, and a straight line joining the intersection points (b1, b2) of the outer circumference of the fiber is taken. , the value obtained by dividing the length of the long axis by the length of the short axis was calculated, and the obtained value was taken as the flatness. A simple numerical average of the results of 10 conjugate fibers randomly extracted from the same image was obtained, and the value rounded to the second decimal place was used as the average flatness value. In addition, among the conjugate fibers for which the flatness was obtained, the value obtained by subtracting the smallest value from the largest value was obtained, and the value was rounded off to the second decimal place as the difference between the maximum flatness value and the minimum flatness value.

E. Fiber diameter A composite fiber bundle is embedded in an embedding agent such as epoxy resin, and the cross section of the fiber in the direction perpendicular to the fiber axis is observed with a scanning electron microscope (SEM) as a magnification at which 10 or more composite fibers can be observed. I took a picture. The area of one conjugate fiber randomly extracted from the photographed image was measured, and the diameter obtained in terms of a perfect circle was measured in μm to the first decimal place. A simple number average of the results obtained in the same manner for 10 conjugate fibers randomly extracted from the same image as above was obtained, and the value rounded to the first decimal place was taken as the fiber diameter (μm).

F. Variation coefficient CV of (distance between center of gravity of polymer/fiber diameter)
In a textile consisting of a bundle of conjugated fibers, the cross section of the textile perpendicular to the length direction of the textile and perpendicular to the fiber axis direction of the conjugated fiber is imaged with a scanning electron microscope (SEM) manufactured by HITACHI as a magnification that allows observation of 20 or more conjugated fibers. was photographed. By analyzing one composite fiber randomly extracted from the photographed image using the computer software WinROOF manufactured by Mitani Shoji, the area of the composite fiber is measured, and the diameter obtained in terms of a perfect circle is measured in μm. Measured to the first decimal place. The obtained value was taken as the fiber diameter (μm).

Further, for the same conjugate fiber as above, the length of a straight line connecting the respective centers of gravity (Gx, Gy) of the low melting point polymer x and the high melting point polymer y in the cross section of the conjugate fiber as shown in FIG. It was measured in units of μm to the first decimal place. The obtained value was defined as the distance between polymer centers of gravity (μm).

For the fiber diameter and the polymer center-of-gravity distance obtained above, a simple number average of the ratio (polymer center-of-gravity distance/fiber diameter) is calculated, and the value rounded to the first decimal place is calculated as (polymer center-of-gravity distance/fiber diameter). This evaluation was performed in the same manner for 20 composite fibers ((1) to (20) in FIG. 5) randomly extracted from the same image, and the standard deviation and average value of the results were obtained. The value was calculated by dividing by and multiplying by 100, and rounded off to the nearest whole number. The obtained value was defined as the coefficient of variation CV (%) of the value of (distance between polymer centers of gravity/fiber diameter).

G. Number of crimp threads (peak/cm)
In a textile made of a conjugate fiber bundle, the conjugate fiber is extracted from the textile so as not to be plastically deformed, one end of the conjugate fiber is fixed, and a load of 1 mg / dtex is applied to the other end for 30 seconds or more. Marking was performed at an arbitrary point where the distance between two points in the fiber axis direction of the fiber was 1 cm. After that, the sample was fixed on a slide glass after adjustment so that the distance between the markings made in advance was 1 cm so as not to plastically deform the composite fiber, and the 1 cm marking of this sample could be observed with a digital microscope. Images were taken at magnification. When the composite fiber had a crimped form as shown in FIG. 6 in the photographed image, the number of crimped crimps existing between the markings was obtained. A simple numerical average of the results obtained by performing this operation on 10 composite fibers was obtained, and the value rounded to the first decimal place was taken as the number of crimp crests (crests/cm).

H. Spinning Stability Spinning was carried out for each of the examples and comparative examples, and the spinning stability was evaluated in four stages based on the following criteria based on the number of yarn breakages per 10 million m (times/10 million m).
S: Excellent spinning stability (number of yarn breaks <1.0)
A: Good spinning stability (1.0 ≤ number of yarn breaks <2.0)
B: Stable spinning (2.0 ≤ number of yarn breaks < 3.0)
C: Inferior in reeling stability (3.0 ≤ number of thread breaks).

I. Textile texture evaluation (fluffiness, resilience, smoothness)
The number of conjugated fibers was adjusted so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1,200 to prepare a 3/1 twill fabric.
However, the CFA and CFB referred to here are the warp and weft densities of the fabric measured in a 2.54 cm section according to JIS-L-1096: 2010 8.6.1, and CFA = Warp × ( It is a value obtained from the formula: warp fineness) ^1/2 , CFB = weft density x (weft fineness) ^1/2 . The resulting woven fabric was subjected to scouring, relaxation treatment, and heat setting under the following conditions in this order, and then evaluated for three textures, ie, bulging feel, rebound feel, and dry feel, using the following methods.

(scouring, wet heat treatment, heat setting)
After scouring for 10 minutes in 80°C warm water containing a surfactant, relaxation treatment was performed in 130°C warm water for 30 minutes. Then, heat setting was performed at 180° C. for 5 minutes.

I-1. Puffiness Using a Telotech constant pressure thickness gauge (PG-14J), the thickness (cm) of a 20 cm×20 cm fabric was measured under a constant pressure (0.7 kPa) to calculate the volume of the fabric. Next, the value obtained by dividing the weight (g) of the fabric by the obtained volume was obtained, and the value rounded off to the second decimal place was taken as the apparent density (g/cm ³ ) of the fabric. Based on the obtained apparent density, the bulging feeling was evaluated in four stages according to the following criteria.
S: excellent swelling feeling (apparent density ≤ 0.5)
A: good swelling feeling (0.5 < apparent density ≤ 0.8)
B: There is a swelling feeling (0.8 < apparent density ≤ 1.1)
C: Poor swelling feeling (1.1<apparent density).

I-2. Feeling of repulsion Using a pure bending tester (KES-FB2) manufactured by Kato Tech, a 20 cm × 20 cm fabric is held with an effective sample length of 20 cm × 1 cm and bent in the weft direction, at a curvature of ± 1.0 cm ^-1 The hysteresis width (gf·cm/cm) was calculated. This operation is performed 3 times per location, and a simple number average of the results of performing this operation for a total of 10 ^locations is obtained.・cm/cm). Based on the obtained bending recovery 2HB×10 ⁻² , the feeling of resilience was evaluated in four stages according to the following criteria.
S: Excellent resilience (bending recovery 2HB × 10 ^-2 ≤ 0.8)
A: good resilience (0.8<bending recovery 2HB×10 ⁻² ≦1.5)
B: There is a sense of repulsion (1.5<bending recovery 2HB×10 ⁻² ≦2.5)
C: Poor resilience (2.5<bending recovery 2HB×10 ⁻² ).

I-3. Smooth feeling Using Kato Tech's automated surface tester (KES-FB4), a 10 cm x 10 cm range of a 20 cm x 20 cm fabric was wrapped with a piano wire, and a 1 cm x 1 cm terminal was applied with a load of 50 g. The variation MMD of the average coefficient of friction was determined by sliding at a speed of 1.0 mm/sec. This operation was performed three times per location, and a simple number average was obtained for the results of performing this operation for a total of 10 ^locations . Based on the obtained frictional fluctuations, the dry feeling was evaluated in four stages based on the following criteria.
S: excellent smooth feeling (1.5 ≤ friction variation)
A: Good smooth feeling (1.2 ≤ friction variation <1.5)
B: Smooth feeling (0.9≦friction variation<1.2)
C: Inferior in dry feeling (friction variation <0.9).

J. Textile function evaluation (water absorption and quick drying, stretchability)
The number of conjugated fibers was adjusted so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1,200 to prepare a 3/1 twill fabric. However, the CFA and CFB referred to here are the warp and weft densities of the fabric measured in a 2.54 cm section according to JIS-L-1096: 2010 8.6.1, and CFA = Warp × ( It is a value obtained from the formula: warp fineness) ^1/2 , CFB = weft density x (weft fineness) ^1/2 . The resulting woven fabric was subjected to scouring, wet heat treatment, alkali treatment and heat setting in this order, and then evaluated for two functions of water absorption and quick drying and stretchability using the following methods. The scouring, relaxation treatment, and heat setting were performed under the same conditions as in the textile feel evaluation, and the alkali treatment was performed under the following conditions.

(alkali treatment)
It was immersed in an aqueous sodium hydroxide solution with a concentration of 0.5 to 2% by mass at a temperature of 90° C. for 30 minutes.

J-1. Water absorption and quick drying After 0.1 cc of water is dropped on a 10 cm x 10 cm fabric, the weight of the fabric is measured every 5 minutes in an environment with a temperature of 20 degrees and a relative humidity of 65 RH%. The time (minutes) at which the content becomes 1.0% or less was determined. A simple numerical average of the results obtained by performing this operation at a total of three locations was obtained, and the value obtained by rounding off the decimal point was taken as the moisture diffusion time (minute). Based on the obtained moisture diffusion time, the water absorption and quick drying properties were evaluated in three stages based on the following criteria.
S: Excellent water absorption and quick drying (moisture diffusion time ≤ 15)
A: Good water absorption and quick drying (15 < water diffusion time ≤ 30)
C: Inferior in water absorption and quick drying (30<moisture diffusion time).

J-2. Stretchability Stretchability was measured according to the elongation rate A method (constant speed elongation method) described in JIS-L-1096:2010, Section 8.16.1. A 17.6 N (1.8 kg) load of the strip method was adopted, and the test conditions were a sample width of 5 cm x length of 20 cm, a clamp interval of 10 cm, and a tensile speed of 20 cm/min. Also, as the initial load, a weight corresponding to a sample width of 1 m was used according to the method of JIS-L-1096:2010. A simple number average of the results of three tests in the horizontal direction of the fabric was obtained, and the value rounded off to the nearest whole number was taken as the elongation rate (%). Based on the obtained elongation rate, the stretchability was evaluated in three stages based on the following criteria.
S: Excellent stretchability (20 ≤ elongation rate)
A: Good stretchability (5 ≤ elongation rate < 20)
C: Poor stretchability (elongation ratio <5).

K. Textile quality evaluation (appearance quality)
The number of conjugated fibers was adjusted so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1,200 to prepare a 3/1 twill fabric. However, the CFA and CFB referred to here are the warp and weft densities of the fabric measured in a 2.54 cm section according to JIS-L-1096: 2010 8.6.1, and CFA = Warp × ( It is a value obtained from the formula: warp fineness) 1/2, CFB = weft density x (weft fineness) 1/2.

The obtained woven fabric was subjected to scouring, relaxation treatment, and heat setting under the same conditions as those used for textile texture evaluation. After that, using an automatic variable angle photometer (GONIOPHOTOMETER GP-200 type) manufactured by Murakami Color Research Laboratory, light was incident on each sample at an incident angle of 60 °, and the light receiving angle was 0 ° to 90 ° for every 0.1 °. was determined by two-dimensional reflected light distribution measurement, and a value was calculated by dividing the maximum light intensity (specular reflection) near the light receiving angle of 60° by the minimum light intensity (diffuse reflection) near the light receiving angle of 0°. This operation was performed 3 times per location, and a simple numerical average of the results of performing this operation for a total of 10 locations was obtained, and the value rounded to the second decimal place was taken as the degree of glare. Based on the degree of glare obtained, the appearance quality of the textile was evaluated in four stages based on the following criteria.
S: excellent appearance quality (glare degree <2.0)
A: Good appearance quality (2.0 ≤ glare degree <2.5)
B: Good appearance quality (2.5 ≤ glare degree <3.0)
C: Inferior in appearance quality (3.0≦glare degree).

L. Abrasion Resistance The number of conjugate fibers was adjusted so that the cover factor (CFA) in the warp direction was 1,100 and the cover factor (CFB) in the weft direction was 1,100 to prepare a plain weave fabric. The resulting plain weave fabric was dyed black using a disperse dye Sumikaron Black S-3B (10% owf). A circle of 10 cm in diameter was cut from the dyed plain weave, moistened with distilled water and attached to a disc. Furthermore, the plain fabric cut into 30 cm squares was fixed on a horizontal plate while dry. A disc on which the fabric moistened with distilled water is attached is brought into horizontal contact with the fabric fixed on a horizontal plate so that the center of the disc draws a circle with a diameter of 10 cm, with a load of 420 g and a speed of 50 rpm. The disc was circularly moved for 10 minutes to rub the two fabrics. After leaving for 4 hours after the end of rubbing, the degree of discoloration of the fabric attached to the disk was evaluated using a discoloration gray scale, grades 1 to 5 in increments of 0.5 grade. Based on the results of the grade judgment obtained, the wear resistance was judged in four grades based on the following criteria.
S: Excellent wear resistance (grade judgment: grade 4.5 or higher)
A: Good wear resistance (class judgment: 3.5 grade, 4 grade)
B: Good wear resistance (class judgment: 2.5 grade, 3 grade)
C: Inferior to abrasion resistance (grade judgment: grade 2 or lower).

[Example 1]
Polyethylene terephthalate (IPA copolymer PET, melt viscosity: 140 Pa s, melting point: 232° C.) obtained by copolymerizing 7 mol % of isophthalic acid as polymer 1, and polyethylene terephthalate (PET, melt viscosity: 130 Pa s, melting point: 254° C.) as polymer 2. °C) was prepared.

After melting these polymers separately at 290°C, polymer 1/polymer 2 was weighed so that the area ratio in the composite cross section was 50/50. Next, the above polymer is flowed into a spinning pack incorporating a composite spinneret shown in FIG. The inflow polymer was discharged from the discharge hole so that the cross section and the joint surface direction of each composite fiber changed (6 types in FIG. 4 are examples of the composite cross section).

After cooling and solidifying the discharged composite polymer flow, an oil agent is applied, wound at a spinning speed of 1500 m / min, and drawn between rollers heated to 90 ° C. and 130 ° C. to obtain 84 dtex-36 filament (fiber diameter 15 μm ) was spun into a composite fiber bundle. At this time, the number of yarn breakages was 1.5 times/10 million m, indicating good spinning stability.

All of the conjugate fibers constituting the obtained conjugate fiber bundle had a flattened cross-sectional shape, the average flatness value among the conjugate fibers was 1.8, and the difference between the maximum and minimum flatness values was was 0.1. Also, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) between conjugate fibers was 18%, confirming that the conjugate fiber bundle of the present embodiment was obtained.

The obtained conjugate fiber bundle is woven, subjected to scouring treatment at 80°C and wet heat treatment at 130°C, and then heat setting at 180°C, whereby the number of crimp crests of the conjugate fiber is 18 crests/cm. A woven fabric composed of composite fiber bundles having a crimped form of .

The woven fabric made of the conjugate fiber bundle has a dry feel (friction fluctuation : 1.3×10 ⁻² ). Furthermore, in the fabric composed of the composite fiber bundle, complex voids are generated between the composite fibers, and a moderate rebound feeling (bending recovery 2HB: 1.1 × 10 ^-2 gf cm / cm) and swelling (apparent density: 0 .8 g/cm ³ ), it has excellent stretchability (elongation rate: 18%) and water absorption and quick drying due to the voids formed between the composite fibers (moisture diffusion time: 25 minutes). was Therefore, the woven fabric composed of the conjugate fiber bundle was a woven fabric excellent in wearing comfort, having both a texture and functions directly related to wearing comfort of the wearer.

Furthermore, in terms of the appearance of the woven fabric, irregular reflection of light due to the formation of voids between the conjugate fibers suppressed appearance unevenness (glare), and had a good appearance quality (glare degree: 2.4). In addition, since the composite fiber is made of polyethylene terephthalate and its copolymer, it has good wear resistance (4th grade) that does not cause discoloration due to fibrillation caused by the polymer, and has properties suitable for clothing textiles. I also found out that Table 1 shows the above results.

[Comparative Example 1]
All the conjugate fibers constituting the conjugate fiber bundle were carried out according to Example 1, except that the direction of the joint surface of each conjugate fiber was not changed.

In Comparative Example 1, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) was 0%, so that all the conjugate fibers constituting the conjugate fiber bundle exhibited the same crimped form. A phase-aligned composite fiber bundle was obtained. As a result, the texture of the textile surface is small, lacking a dry feel, and the voids between the conjugate fibers are also small, resulting in a lack of a bulging feel. Table 1 shows the results.

[Comparative Example 2]
Polymer 1 was changed to the same PET as polymer 2, and after stretching, the processing speed was 250 m / min, and the stretching ratio was 1.05 times between rollers, while heating with a heater set to 180 ° C., using a friction disk. , was carried out according to Comparative Example 1 except that false twisting was performed at a number of revolutions such that the number of false twists was 3000 T/m.

In Comparative Example 2, since the conjugated fibers were made of the same polymer, all the conjugated fibers constituting the conjugated fiber bundle developed a uniform crimped shape. Therefore, unevenness on the surface of the textile becomes monotonous and lacks a smooth feeling. Table 1 shows the results.

[Comparative Example 3]
Polyethylene terephthalate (IPA copolymer PET, melt viscosity: 140 Pa s, melting point: 232° C.) obtained by copolymerizing 7 mol % of isophthalic acid as polymer 1, and polyethylene terephthalate (PET, melt viscosity: 130 Pa s, melting point: 254° C.) as polymer 2. °C) was prepared.

After melting these polymers separately at 290° C., they were weighed so that the area ratio in the composite cross section was 50/50, and polymer 1 and polymer 2 were bonded side-by-side with a round cross section as shown in FIG. The inflow polymer was discharged from the discharge hole so as to form a composite cross section. At this time, the discharge amount of each discharge hole was adjusted so that the composite fiber bundle was composed of two types of composite fibers having different fiber diameters.

After cooling and solidifying the discharged composite polymer flow, an oil agent is applied, wound at a spinning speed of 1500 m / min, and drawn between rollers heated to 90 ° C. and 130 ° C. to obtain 84 dtex-36 filament (fiber diameter 14 μm (minimum value: 11 μm (18 filaments), maximum value: 17 μm (18 filaments))). The fiber diameter of the composite fiber bundle here was calculated by (minimum value+maximum value)/2.
The resulting conjugate fiber bundle was woven, subjected to scouring treatment at 80°C and wet heat treatment at 130°C, and then heat-set at 180°C to obtain a fabric composed of the conjugate fiber bundle. .

In Comparative Example 3, since the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) is 0%, the conjugate fibers constituting the conjugate fiber bundle exhibit the same crimp development force, and the crimp phase It became a composite fiber bundle in which the As a result, the texture of the textile surface is small, and in addition to lacking a dry feel, the voids between the conjugate fibers are also small, and the feeling of swelling and resilience is lacking.
In addition, since conjugate fibers with different fiber diameters are wound at the same time during fiber production, yarn interference occurs due to different cooling and solidification behaviors, resulting in poor yarn production stability. Table 1 shows the results.

[Comparative Example 4]
Polyethylene terephthalate (IPA copolymer PET, melt viscosity: 140 Pa s, melting point: 232° C.) obtained by copolymerizing 7 mol % of isophthalic acid as polymer 1, and polyethylene terephthalate (PET, melt viscosity: 130 Pa s, melting point: 254° C.) as polymer 2. °C) was prepared.

After melting these polymers separately at 290 ° C., they were weighed so that the area ratio in the composite cross section was 50/50, and the flat shape and polymer 1 and polymer 2 were side-by-side as shown in FIG. The inflowing polymer was discharged from the discharge hole so that the composite cross section was bonded to the composite fiber (there was no change in the bonding surface direction for each composite fiber). At this time, the discharge holes were adjusted so that the average value of flatness among the composite fibers constituting the composite fiber bundle was 1.8 and the difference between the maximum and minimum flatness was 0.5.

After cooling and solidifying the discharged composite polymer flow, an oil solution is applied, wound at a spinning speed of 1500 m / min, and drawn between rollers heated to 90 ° C. and 130 ° C. to obtain 84 dtex-36 filament (fiber diameter 15 μm). of composite fiber bundles were produced.
The resulting conjugate fiber bundle was woven, subjected to scouring treatment at 80°C and wet heat treatment at 130°C, and then heat-set at 180°C to obtain a fabric composed of the conjugate fiber bundle. .

In Comparative Example 4, the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) is 31%, so that when it is made into a textile, the unevenness of the textile surface becomes finer, the friction fluctuation is small, and the texture is monotonous. became.
In addition, since conjugate fibers with greatly different flatnesses are wound at the same time during fiber production, yarn interference occurs due to different cooling and solidification behaviors, resulting in poor spinning stability.

[Example 2]
Everything was carried out according to Example 1 except that the surface layer of the composite fiber was covered with PET and the composite cross section was changed as shown in FIG. 1(b). The ratio S/D between the minimum thickness S of PET and the fiber diameter D determined by the method described above was 0.03.

In Example 2, since the copolymer PET is not exposed on the surface layer of the conjugate fiber, not only the wear resistance is improved, but also the difference in cooling between the PET and the copolymer PET is alleviated, so that after ejection from the nozzle Yarn bending could be suppressed, and the spinning stability was also excellent. Table 1 shows the results.

[Example 3]
Everything was carried out according to Example 1, except that the cross-sectional shape of the conjugate fiber was changed to a flat multi-lobed shape having eight protrusions on the surface as shown in FIG. 1(c).

In Example 3, unevenness in the appearance of the textile (glittering) was suppressed due to irregular reflection of light by forming unevenness on the surface of the composite fiber, and the quality of the appearance was improved. Furthermore, by combining conjugate fibers having an uneven surface, fine inter-fiber voids are formed in the conjugate fiber bundle, and dry feeling and water absorption and quick-drying properties are improved. Table 1 shows the results.

[Example 4]
Everything was carried out according to Example 1, except that the average value of the flatness between the conjugate fibers was changed to 1.3.

In Example 4, as the average value of flatness of the conjugate fibers decreased, the crimped shape developed by the heat treatment became finer and closer to a coil shape. As a result, not only is the stretchability increased, but also the flattened edges are reduced to reduce friction and improve wear resistance. Table 2 shows the results.

[Comparative Example 5]
Everything was carried out according to Example 1, except that the cross-sectional shape of the conjugated fiber was changed so as to have a circular cross-section as shown in FIG.

In Comparative Example 5, since the coefficient of variation CV of the value of (distance between polymer centers of gravity/fiber diameter) was 0%, all the conjugate fibers constituting the conjugate fiber bundle exhibited the same crimped form, and crimped. This resulted in a converged composite fiber bundle that was in phase. As a result, the textile surface does not have an uneven texture and has a flat texture. In addition, since there are no voids between the composite fibers, the fabric lacks a feeling of swelling, a feeling of resilience, and quick-drying water absorption. Table 2 shows the results.

[Example 5]
Everything was carried out according to Example 1 except that polymer 2 was changed to PET having a melt viscosity of 30 Pa·s.

In Example 5, the crimped form was more strongly expressed, and not only the resulting woven fabric had an increased feeling of fullness, but also the stretchability was improved. Table 2 shows the results.

[Examples 6 and 7]
Everything was carried out according to Example 1 except that the discharge amount was changed so that the fiber diameter of the composite fiber was 10 μm (Example 6) and 20 μm (Example 7).

In Example 6, by setting the fiber diameter of the conjugate fiber to 10 μm, the diffused reflection of light was increased, and the appearance quality was improved by suppressing the appearance unevenness (glare) when made into textiles. Flexibility improved as the bending stiffness of the book decreased. Table 2 shows the results.

In Example 7, by setting the fiber diameter to 20 μm, the crimped loops developed by the heat treatment became larger, and in addition to improving the dry feeling and the swelling feeling, the bending hardness was increased. Therefore, a characteristic elastic tactile sensation was obtained. Table 2 shows the results.

[Example 8]
Everything was carried out according to Example 1, except that the polymer 2 was changed to polyethylene terephthalate (TiO ₂ -containing PET) containing 5.0 wt% of titanium oxide.

In Example 8, the titanium oxide on the surface of the composite fiber diffusely reflects light, thereby suppressing the increase or decrease in reflection (glare) depending on the angle of incidence of light, thereby improving the appearance quality of the textile. In addition, the titanium oxide inside the conjugate fiber provided functionality such as anti-see-through and ultraviolet shielding. Table 2 shows the results.

[Examples 9 and 10]
Everything was carried out according to Example 1 except that the polymer 1 was changed to polypropylene terephthalate (PPT) (Example 9) and polybutylene terephthalate (PBT) (Example 10).

In Examples 9 and 10, the properties of rubber elasticity possessed by PPT and PBT used as the polymer 1 are combined, and when the composite fiber bundle is used as a textile, not only does it exhibit a texture with excellent flexibility, but it also has a stretch function. was also significantly improved. Table 2 shows the results.

[Example 11]
After winding at a spinning speed of 2500 m/min and storing for one month under standard conditions (temperature of 23°C, relative humidity of 65%), hot pin temperature of 70°C was applied at the same draw ratio as the upper limit of the natural draw ratio of the composite fiber bundle. Everything was carried out according to Example 1, except that non-uniform stretching was applied at a set temperature of 130°C.
In Example 11, since a difference in dyeability occurs between the stretched portion and the unstretched portion of the conjugate fiber, when the conjugate fiber bundle is used as a textile, the shade of the color is more emphasized, and the heather tone like a natural material is obtained. was obtained. Table 2 shows the results.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application (Japanese Patent Application No. 2021-122063) filed on July 27, 2021, the content of which is incorporated herein by reference.

In the conjugate fiber bundle of the present embodiment, by precisely controlling the crimped form of each conjugate fiber that constitutes the conjugate fiber bundle, the portions where the crimp phases are aligned between adjacent conjugate fibers are aligned. Differences in the gaps are created where there are no gaps, and complex gaps and irregularities can be formed between the composite fibers, and a unique smooth feel can be expressed.

Therefore, by utilizing the composite fiber bundle of the present invention, it is possible to obtain a textile that is comfortable to wear and has a moderate resilience due to the complex voids between the composite fibers and a puffy texture. Therefore, in addition to general clothing such as jackets, skirts, pants, and underwear, sports clothing, clothing materials, interior products such as carpets and sofas, vehicle interiors such as car seats, It can be suitably used for a wide variety of textile products such as cosmetics, cosmetic masks, and health products.

x: Low-melting point polymer y: High-melting point polymer a1, a2: Two points b1, b2 farthest apart on the outer circumference of the fiber: Within a straight line connecting the two farthest points on the outer circumference of the fiber Intersection point Gx of a straight line perpendicular to the point and the circumference of the fiber: Center of gravity Gy of low melting point polymer: Center of gravity CF of high melting point polymer: Composite fiber Cr: Crimp crest 1: Weighing plate 2: Distributing plate 3: Discharge plate

Claims

A conjugate fiber bundle composed of conjugate fibers composed of at least two kinds of polymers having different melting points, wherein the variation coefficient CV of the value of (distance between polymer centers of gravity/fiber diameter) between the conjugate fibers is 5 to 30%. A composite fiber bundle characterized by:
The conjugate fiber bundle according to claim 1, wherein the difference between the maximum flatness value and the minimum value of the flatness between the conjugate fibers is less than 0.5.
The composite fiber bundle according to claim 1 or 2, characterized in that the average value of flatness between the composite fibers is 1.2 to 3.0.
The composite fiber bundle according to any one of claims 1 to 3, characterized in that the surface layer of the composite fiber is covered with one type of polymer.
A textile product partly containing the composite fiber bundle according to any one of claims 1 to 4.