JP2021091983A - Hollow fiber and fiber aggregate - Google Patents

Abstract

To improve the dyeability and wear resistance of fibers that reflect near infrared radiation efficiently.SOLUTION: A hollow fiber 10, 25 (monofilament) has a cross section of a star-shaped polygon, with a fiber diameter of 1 μm or more and 50 μm or less. The hollow fiber 10, 25 has a hollow part 2A, 2B.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to hollow fibers and fiber aggregates.

Woven fabrics, knitted fabrics, genuine leather, synthetic leather, etc. may be used as the skin for interior articles and the like.
However, these epidermis do not have particularly excellent reflection performance with respect to the reflection of near infrared rays.
Therefore, for example, when sunlight is incident from the window glass of an automobile, most of the near infrared rays of sunlight are absorbed by the interior articles and stored as heat energy. Therefore, the temperature of the interior article rises, and the temperature may become so high that it is difficult to touch it by hand.
In addition, an air conditioner is used to cool an interior article whose temperature has risen, which reduces the efficiency of the air conditioner, which in turn reduces the energy consumption efficiency of the automobile.
Therefore, in order to suppress the temperature rise of various articles such as interior articles, various studies have been conducted on the skin material (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-358664

Under these circumstances, the development of fibers that efficiently reflect near-infrared rays is eagerly desired.
However, fibers that efficiently reflect near infrared rays do not always have sufficient dyeability and abrasion resistance, and improvements in these performances have been required.
The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to improve the dyeability and abrasion resistance of fibers that efficiently reflect near infrared rays. The present disclosure can be realized in the following forms.

[1] The cross section is a star polygon, and the fiber diameter is 1 μm or more and 50 μm or less.
Hollow fiber with a hollow portion.

The hollow fibers of the present disclosure have good dyeability and abrasion resistance while efficiently reflecting near infrared rays. Since the hollow fiber has a hollow portion, the weight can be reduced. Since the hollow fiber has a hollow portion, the amount of material used for manufacturing is reduced, and resource saving can be realized. In the hollow fiber, not only the dye permeates from the outer peripheral surface, but also the dye permeates from the hollow part, so that the dye spreads more throughout the fiber in the bath at the time of dyeing.

The present disclosure will be further described in the following detailed description with reference to the plurality of references mentioned, with reference to non-limiting examples of typical embodiments according to the present disclosure.
It is a perspective view of the hollow fiber of an example of an embodiment. It is a cross-sectional view of the hollow fiber of an example of an embodiment. It is a cross-sectional view of the hollow fiber of an example of an embodiment. It is a cross-sectional view of the hollow fiber of an example of an embodiment. It is a cross-sectional view of the hollow fiber of an example of a reference form. It is the schematic of the cloth (fiber aggregate) of an example of an embodiment.

Here, a desirable example of the present disclosure is shown.
[2] The hollow fiber according to [1], wherein the star-shaped polygon is a hexagram or a pentagram.
This fiber has good dyeability and abrasion resistance while efficiently reflecting near infrared rays.

[3] The hollow fiber according to [1] or [2], wherein the length of each side constituting the outer shape of the star-shaped polygon is 1 μm or more and 5 μm or less.
This hollow fiber has high reflection efficiency of near infrared rays.

[4] The hollow fiber according to any one of [1] to [3], wherein the hollow ratio is 5% or more and 50% or less.
This hollow fiber is lightweight while maintaining practical strength.

[5] The hollow fiber according to any one of [1] to [4], which contains a synthetic resin as a main component.
This hollow fiber is advantageous in terms of manufacturing cost because the cross section of a star-shaped polygon can be manufactured only by changing the shape of the spinneret (nozzle).

[6] The hollow fiber according to any one of [1] to [5], which is colored with a dye.
Since this hollow fiber is thick among fibers having high near-infrared reflection efficiency, it can express a dark color by coloring with a dye.

[7] A fiber aggregate using the fiber according to any one of [1] to [6].
This fiber aggregate has good dyeability and abrasion resistance while efficiently reflecting near infrared rays.

Hereinafter, embodiments will be described in detail. In this specification, the description using "~" for the numerical range shall include the lower limit value and the upper limit value unless otherwise specified. For example, in the description of "10 to 20", both the lower limit value "10" and the upper limit value "20" are included. That is, "10 to 20" has the same meaning as "10 or more and 20 or less".

1. Hollow fibers 10, 25
(1) Cross-sectional shape of hollow fibers 10 and 25 The hollow fibers 10 and 25 (single fibers) have a star-shaped polygonal cross section. The hollow fibers 10 and 25 have hollow portions 2A and 2B in the center in the cross-sectional shape. Hollow fibers 10 and 25 are tubular fibers having cavities in the fibers.
As the star-shaped polygon, a six-pointed star or a five-pointed star is preferable.
In the case of the hexagram, as shown in FIG. 2, the cross section has 12 vertices 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22.
In the case of the pentagram, as shown in FIG. 3, the cross section has 10 vertices 31, 32, 33, 34, 35, 36, 37, 38, 39, 40.
The method for obtaining hollow fibers 10 and 25 having a deformed cross section having a star-shaped polygonal cross section is not particularly limited. For example, there are [1] a method of deforming the shape of the base used at the time of melt spinning, and [2] a method of composite spinning two or more kinds of polymers and dividing them into a deformed cross section. The fibers produced by the latter method are also called split fiber yarns.

(2) Fiber diameter φ1, φ2
The fiber diameters φ1 and φ2 of the hollow fibers 10 and 25 are 1 μm or more and 50 μm or less, and preferably 2 μm or more and 25 μm or less, from the viewpoint of improving dyeability and abrasion resistance while efficiently reflecting near infrared rays. More preferably, it is 3 μm or more and 20 μm or less.
The fiber diameters φ1 and φ2 are the diameters of the circumscribed circles C1 and C2 indicated by virtual lines. The fiber diameters φ1 and φ2 can be measured by photographing the cross section of the fiber with a scanning electron microscope.
Assuming that the fiber diameters φ1 and φ2 are within the above range, the lengths L1 and L2 of each side constituting the outer shape of the star-shaped polygon, that is, the sides connecting the adjacent vertices, are equal to or several times the near-infrared wavelength. It is presumed that the reflection efficiency of near-infrared rays will increase because a light scattering phenomenon called Mie scattering occurs in the region of. Specifically, in the case of FIG. 2, the side connecting the adjacent vertices is the side connecting the vertices 11 and 12, the side connecting the vertices 12 and the vertices 13, and the vertices 13. The side connecting the vertices 14 and the vertices 14, the side connecting the vertices 14 and the vertices 15, the side connecting the vertices 15 and the vertices 16, the side connecting the vertices 16 and the vertices 17, the vertices 17 and the vertices. A side connecting 18 and a side connecting apex 18 and a vertex 19, a side connecting a vertex 19 and a vertex 20, a side connecting a vertex 20 and a vertex 21, a vertex 21 and a vertex 22 This is the side that connects the vertices 22 and the vertices 11.
In the case of FIG. 3, the sides connecting adjacent vertices are specifically the side connecting the vertices 31 and 32, the side connecting the vertices 32 and 33, and the vertices 33 and the vertices. The side connecting 34, the side connecting vertex 34 and vertex 35, the side connecting vertex 35 and vertex 36, the side connecting vertex 36 and vertex 37, the vertex 37 and vertex 38 A side connecting the apex 38 and the apex 39, a side connecting the apex 39 and the apex 40, and a side connecting the apex 40 and the apex 31.

Here, the reason for presuming that the dyeability is improved when the fiber diameters φ1 and φ2 are within the above ranges will be described. The case of a six-pointed star will be described as an example. FIG. 4 schematically shows a state in which the hollow fiber 10 having a hexagram in cross section is colored by the dye D. FIG. 5 schematically shows a state in which the fiber 100 having a triangular cross section is colored by the dye D. As described above, since the reflection efficiency of near infrared rays is presumed to depend on the side length L1 in the cross section, the reflection efficiency of near infrared rays is high for both the hollow fiber 10 in FIG. 4 and the fiber 100 in FIG. As described above, it is considered that the side lengths L1 are aligned. Further, it is assumed that the hollow fiber 10 in FIG. 4 and the fiber 100 in FIG. 5 are made of the same material. Then, in the hollow fiber 10 and the fiber 100, the amount of the dye D (dye molecule) that permeates into the same cross-sectional area becomes the same. Here, when FIGS. 4 and 5 are compared, it is presumed that the reflection efficiencies of near infrared rays are the same because the lengths L1 of the sides constituting the outer shape are the same in both of them based on the above assumptions. Comparing the degree of coloring, the hollow fiber 10 in FIG. 4 is thicker than the fiber 100 in FIG. 5, so that the amount of the dye D that permeates is large and the color looks dark.

Next, the reason why the wear resistance is improved when the fiber diameters φ1 and φ2 are within the above ranges will be described. Comparing FIGS. 4 and 5, from the above assumptions, it is estimated that the reflection efficiencies of near infrared rays are the same because the lengths L1 of the sides constituting the outer shape are the same. Comparing the abrasion resistance, it is considered that the hollow fiber 10 in FIG. 4 is thicker than the fiber 100 in FIG. 5, and therefore the abrasion resistance is improved.

In the above description, the case where the cross section is a hexagram is described, but the same applies when the cross section is another star-shaped polygon.

From the above consideration, the hollow fiber 10 having a star-shaped polygonal cross section and fiber diameters φ1 and φ2 within a predetermined range is dyed while having a near-infrared reflection efficiency equivalent to that of the fine fiber 100. It is considered that the property and abrasion resistance are improved.

(3) Lengths L1 and L2 of each side constituting the outer shape of the star polygon
The lengths L1 and L2 of each side constituting the outer shape of the star polygon are preferably 1 μm or more and 5 μm or less, and 2 μm or more and 5 μm or less, from the viewpoint of improving the reflection efficiency of near infrared rays due to Mie scattering. Is more preferable.

(4) Hollowness The hollow fibers 10 and 25 (single fibers) preferably have a hollow ratio of 5% or more and 50% or less, and 7% or more and 30%, from the viewpoint of weight reduction while maintaining practical strength. It is more preferably 10% or more and 20% or less.
The hollow ratios of the hollow fibers 10 and 25 in the present disclosure refer to the ratio of the area of the hollow portion in the cross-sectional shape of the single fiber (single thread), and the micrograph photography device is attached to an optical microscope to obtain the single fiber cross section. The cross-sectional shape was photographed, and as shown in the schematic diagram of FIG. 2, the values of the area A (hollow portion) and the area B (non-hollow portion) were calculated and obtained by the following equation. The average value for fibers.
Hollow ratio (%) = [(Area A) / (Area A + Area B)] × 100

(5) Material of Hollow Fibers 10 and 25 The material of the hollow fibers 10 and 25 is not particularly limited. The hollow fibers 10 and 25 may be synthetic fibers, regenerated fibers, or semi-synthetic fibers.
The material of the synthetic fiber is not particularly limited. For example, the main components are various synthetic resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polylactic acid, polyamide 6, polyamide 66, polyacrylic resin, and polyolefins such as polypropylene. Can be. The main component refers to a substance having a content (% by mass) of 50% by mass or more. If necessary, additive components usually used for resins, such as strengthening agents, flame retardants, antistatic agents, antioxidants, fillers, etc., may be added to synthetic fibers within a range that does not impair desired physical properties. it can.
As synthetic fibers, for example, polyester fibers such as polyethylene terephthalate (PET) fiber, polybutylene terephthalate (PBT) fiber, polytrimethylene terephthalate (PTT) fiber, and polylactic acid fiber; polyamide fiber such as polyamide 6 fiber and polyamide 66 fiber. Fibers: Various synthetic fibers such as polyacrylic fibers and polyolefin fibers such as polypropylene fibers can be used.
The synthetic fiber may be an undrawn yarn or a semi-drawn yarn.
The recycled fiber is not particularly limited. For example, cellulosic rayon, purified cellulose fiber lyocell and the like can be used. There are various types of rayon such as polynosic, viscose, and cupra rayon.
The semi-synthetic fiber is not particularly limited. For example, cellulosic acetate, protein-based promix, and the like can be used.
It is preferable that the hollow fibers 10 and 25 do not contain carbon black. This is because the reflection performance of the hollow fibers 10 and 25 deteriorates when carbon black is contained.

(6) Dyes used for coloring hollow fibers 10 and 25 Dyes are not particularly limited. As the dye, one or more selected from the group consisting of disperse dyes, acidic dyes, cationic dyes, slene dyes (virt dyes), direct dyes, sulfur dyes, reactive dyes, and naphthol dyes can be used.
Disperse dyes are suitable for dyeing polyester fibers and the like. Examples of the disperse dye include dyes such as azo dyes, anthraquinone dyes, and quinophthalone dyes.
Acid dyes are suitable for dyeing polyamide fibers such as nylon. Examples of acid dyes include azo dyes, anthraquinone dyes, pyrazolone dyes, phthalocyanine dyes, xanthene dyes, indigoid dyes and triphenylmethane dyes.
The cationic dye is suitable for dyeing a copolymerized polyester fiber or the like in which a functional group having dyeability with respect to the cationic dye is introduced. The cation dye is generally a salt consisting of a dye cation having a positive charge in the coloring part and a colorless anion, and is water-soluble. When classified by chemical structure, triarylmethane dye, methine dye, azo dye, and azamethylene are used. Examples thereof include dyes such as dyes and anthracinone dyes.
Examples of slene dyes include dyes such as anthraquinone dyes and indigo dyes.

(7) Effects of Hollow Fibers 10 and 25 of the Present Embodiment The effects of the hollow fibers 10 and 25 of the present embodiment will be described in comparison with the fibers 100 of FIG.
In general, fabrics and the like using fibers having a fine fiber diameter of about several μm have low dyeability. Therefore, when the fabric or the like is made dark (for example, black), a stock solution in which carbon black is kneaded into the fibers. Use colored fibers. However, carbon black cannot be used to exhibit the heat shielding function.
Even when the fiber diameter is reduced to 1 μm or more and 5 μm or less as in the fiber 100 of FIG. 5 to increase the reflection efficiency of near infrared rays due to Mie scattering, it is necessary to exhibit a heat shielding function, that is, near infrared rays. Carbon black cannot be used because it is necessary to increase the reflection efficiency of infrared rays. Therefore, with the fiber 100 of FIG. 5, there is a problem that a dark-colored (for example, black) fabric or the like cannot be obtained.
Further, in the fiber 100 of FIG. 5, since the fiber diameter is as thin as 1 μm or more and 5 μm or less, the fiber may be cut by abrasion, and it is difficult to apply it to applications requiring abrasion resistance (for example, automobile door trim). It was.

With respect to the fiber 100 of FIG. 5, the hollow fibers 10 and 25 of the present embodiment have good dyeability and abrasion resistance while maintaining the property of efficiently reflecting near infrared rays.
Specifically, in the case of the hollow fiber 10 of FIG. 2, there are six portions 41, 42, 43, 44, 45, 46 having an equilateral triangular cross section, and the respective portions 41, 42, 43, 44, respectively. At 45 and 46, there are two sides each having a length L1 having a high reflection efficiency of near infrared rays. Therefore, the hollow fiber 10 has a high reflection efficiency of near infrared rays. In the case of the hollow fiber 25 of FIG. 3, there are five portions 51, 52, 53, 54, 55 having an isosceles right triangle cross section, and near infrared rays are present at the respective portions 51, 52, 53, 54, 55. There are two sides of length L2 with high reflection efficiency. Therefore, the hollow fiber 25 has a high reflection efficiency of near infrared rays.
Since the hollow fibers 10 and 25 are thicker than the fiber 100 of FIG. 5, more dye D can be impregnated and the hollow fibers 10 and 25 can be darkened. The fiber 100 of FIG. 5 has a fiber diameter as thin as 1 μm or more and 5 μm or less from the viewpoint of improving the reflection efficiency of near infrared rays due to Mie scattering. Considering the reflection efficiency of near infrared rays, the fiber 100 preferably does not contain carbon black as described above. When the fiber 100 was colored with a dye without using carbon black, the amount of the dye that permeated the fiber 100 was small because the fiber 100 was thin, and it was difficult to make the color dark. On the other hand, in the case of hollow fibers 10 and 25, by making the cross section a star polygon, the fiber diameters φ1 and φ2 are thickened to stain while forming a portion having high reflection efficiency of near infrared rays due to Mie scattering. The amount of dye used can be increased to produce a darker color (eg, black). By using the hollow fibers 10 and 25, a dark-colored (for example, black) fiber aggregate 61 can be produced (see FIG. 6).

Since the hollow fibers 10 and 25 have hollow portions 2A and 2B, the number of materials used for manufacturing is reduced, and resource saving can be realized.
In the hollow fibers 10 and 25, not only the dye permeates from the outer peripheral surface toward the inside, but also the dye permeates from the inner peripheral surface toward the outside, so that the dye spreads more throughout the fiber. Therefore, the hollow fibers 10 and 25 are likely to be darkened.
Since the hollow fibers 10 and 25 are thicker than the fibers 100 of FIG. 5, they have good wear resistance.
In the hollow fiber 10, the portions 41, 42, 43, 44, 45, 46 having an equilateral triangular cross section are regularly arranged around the central axis O1, and the reflection efficiency is high with respect to near infrared rays from any direction.
In the hollow fiber 25, the portions 51, 52, 53, 54, 55 having an isosceles right triangle in cross section are regularly arranged around the central axis O2, and the reflection efficiency is high with respect to near infrared rays from any direction.
Since the vertices 12, 14, 16, 18, 20, 22 in the hollow fiber 10 and the vertices 32, 34, 36, 38, 40 in the hollow fiber 25 are recessed valley bottoms, the vertices are hollow from the vicinity of these vertices. Dyes easily permeate into the portions of the fibers 10 and 25 near the central axes O1 and O2, and even if they are thick, they are easily colored.

2. Fiber assembly 61
(1) Form of Fiber Assembly 61 The fiber assembly 61 uses hollow fibers 10 and 25. The contents of the hollow fibers 10 and 25 in the fiber assembly 61 are not particularly limited. The content of the hollow fibers 10 and 25 in the fiber assembly 61 is preferably 4% by mass or more, more preferably 8% by mass, still more preferably 16% by mass, from the viewpoint of increasing the reflection efficiency of near infrared rays. The content of the hollow fibers 10 and 25 in the fiber assembly 61 may be 100% by mass.
The fiber assembly 61 may contain fibers other than the hollow fibers 10 and 25.
The form of the fiber assembly 61 is not particularly limited. The fiber aggregate 61 is at least one selected from the group consisting of woven fabrics, knitted fabrics, spunbonded non-woven fabrics, melt blown non-woven fabrics (melt blown non-woven fabrics), needle punched non-woven fabrics, and flocked sheets from the viewpoint of easy production. desirable.
The structure of the woven fabric is not particularly limited, and for example, various woven fabrics such as plain woven fabric, twill woven fabric, red woven fabric and combinations thereof can be used.
The knitted fabric may be either a weft knit or a warp knit. As the weft, the basic structure (flat knitting, rubber knitting, pearl knitting) and its changing structure can be exemplified. In addition, as the warp edition, the basic organization (Denby edition, code edition, atlas edition, chain edition) and its changing organization can be exemplified.
The spunbonded non-woven fabric is produced, for example, by melting a resin to form fibers (threads), opening and depositing the fibers on a net to form a web, and then bonding them in a sheet shape.
Melt-blown non-woven fabric is produced, for example, by melting a resin and injecting it from the periphery of a spinning nozzle to thin the fibers into a sheet.
The needle punched non-woven fabric is produced by entwining the fibers with each other by the reciprocating motion of a needle made of metal or the like.
The flocked sheet is produced, for example, by flocking fibers on a sheet-shaped substrate (base portion). From the viewpoint of ease of production, electrostatic flocking (flocking) is preferably used.

(2) Thickness of Fiber Assembly 61 The thickness of the fiber assembly 61 is not particularly limited. The thickness of the fiber assembly 61 is preferably 0.1 mm or more and 10 mm or less, more preferably 0.2 mm or more and 5 mm or less, and further preferably 0.3 mm or more and 3 mm or less from the viewpoint of suppressing the manufacturing cost and increasing the reflectance. preferable.

(3) Metsuke Amount of Fiber Aggregate 61 The basis weight of the fiber aggregate 61 is not particularly limited. ^{The amount of the fiber aggregate 61 is preferably 8 g / m 2} or more and 1500 g / m ² or less, more preferably 12 g / m ² or more and 1000 g / m ² or less, from the viewpoint of suppressing the manufacturing cost and increasing the reflectance. It is more preferably 16 g / m ² or more and 500 g / m ² or less.

(4) Use of Fiber Aggregate 61 The fiber aggregate 61 is suitably used as, for example, a skin material. The skin material is widely used as a skin material for articles (including parts) in various technical fields. The technical field in which the skin material is used is not particularly limited. For example, in various industries such as automobiles, rolling stock and other vehicles, aircraft, ships, construction, and apparel, it is suitably used in technical fields related to skin materials. Specific examples of articles using skin materials include vehicle interior materials such as door trims, roof trims, package trays and seats, furniture such as sofas, and daily necessities such as shoes, wallets and clothes.
The skin material can be suitably used for articles that can be heated to a high temperature by sunlight, for example, door trims (particularly the upper portion), package trays, and sheets.
The material of the base material of various articles is not particularly limited. As the material, for example, a polyolefin resin is preferably used. Specific examples of the polyolefin resin include polypropylene, polyethylene, polybutene, polystyrene, ethylene-propylene copolymer, ethylene-methacrylic acid copolymer, ethylene-ethylacrylate copolymer, and ethylene / propylene / diene ternary compound. Examples thereof include polymers, ethylene / vinyl acetate copolymers, polyamide 6, ABS, and polycarbonate. Moreover, as a composite material, glass fiber / PP, glass fiber / polyamide 6, natural fiber / PP and the like can be mentioned.

(5) Action and Effect of Fiber Aggregate 61 of the present embodiment Since the fiber aggregate 61 of the present embodiment has near-infrared ray reflectivity, it is possible to suppress a temperature rise of various articles coated with the fiber aggregate 61. Further, since the hollow fibers 10 and 25 used for the fiber aggregate 61 have good dyeability, the fiber aggregate 61 can be darkened. Further, since the hollow fibers 10 and 25 used for the fiber assembly 61 have good wear resistance, the wear resistance of the fiber assembly 61 is improved.

The above examples are for illustration purposes only and are not to be construed as limiting the invention. Although the present invention has been described with reference to typical embodiments, the language used in the description and illustration of the invention is understood to be descriptive and exemplary rather than restrictive. As described in detail here, modifications can be made within the scope of the appended claims without departing from the scope or nature of the invention in that form. Although specific structures, materials and examples have been referred to herein in detail of the invention, it is not intended to limit the invention to the disclosures herein, but rather the invention is claimed in the accompanying claims. It shall cover all functionally equivalent structures, methods and uses within the scope.

2A, 2B ... Hollow part 10 ... Hollow fiber 25 ... Hollow fiber 61 ... Fiber aggregate 100 ... Fiber C1 ... Circumscribed circle (virtual line)
C2 ... Circumscribed circle (virtual line)
D ... Dye O1 ... Central axis O2 ... Central axis φ1 ... Fiber diameter φ2 ... Fiber diameter

Claims (7)

The cross section is a star polygon, and the fiber diameter is 1 μm or more and 50 μm or less.
Hollow fiber with a hollow portion. The hollow fiber according to claim 1, wherein the star-shaped polygon is a hexagram or a pentagram. The hollow fiber according to claim 1 or 2, wherein the length of each side constituting the outer shape of the star-shaped polygon is 1 μm or more and 5 μm or less. The hollow fiber according to any one of claims 1 to 3, wherein the hollow ratio is 5% or more and 50% or less. The hollow fiber according to any one of claims 1 to 4, which contains a synthetic resin as a main component. The hollow fiber according to any one of claims 1 to 5, which is colored with a dye. A fiber assembly using the hollow fiber according to any one of claims 1 to 6.

Images