Fiber for artificial hair, and hair decoration product

Abstract

The purpose of the present invention is to provide a fiber for artificial hair having reduced glossiness. One embodiment of the present invention is a fiber for artificial hair, which is provided with a plurality of hollow parts extending in the longitudinal direction. It is preferable that a first hollow section among the plurality of hollow sections is positioned substantially at the center of a fiber cross-section perpendicular to the longitudinal direction of the artificial hair fiber. And one or a plurality of second hollow sections among the plurality of hollow sections are each positioned closer to the outer edge direction of the artificial hair fiber than the first hollow section in the fiber cross-section.

Description

Technical Field

[0001] This invention relates to a fiber for artificial hair and hair decoration products. Background Technology

[0002] In headwear products such as wigs, hair extensions, partial wigs, headbands, and doll hair, artificial hair is becoming increasingly important as a substitute for human hair. The materials used to make artificial hair fibers include acrylic resins, vinyl chloride resins, or polyester resins, and artificial hair fibers made from these resins are already available on the market.

[0003] Patent Document 1 discloses a synthetic hair fiber, characterized by containing hollow fibers having a hollow portion with a hollow ratio of 10% to 50%. Furthermore, Patent Document 2 discloses a synthetic hair fiber characterized by having a void in the central portion of the fiber cross-section, the area of ​​the void being 5% to 50% of the total area of ​​the fiber cross-section, the cross-sectional shape of the fiber cross-section being a flat, multi-lobed shape, and the void having a first side and a second side inclined at an angle of 70 degrees or more and 110 degrees or less relative to the long axis of the fiber cross-section.

[0004] Existing technical documents

[0005] Patent documents

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2008-285772

[0007] [Patent Document 2] WO2014 / 196642 Summary of the Invention

[0008] In recent years, there has been a demand for lightweight synthetic hair fibers. For example, Patent Documents 1 and 2 disclose synthetic hair fibers with hollow sections. However, conventional synthetic hair fibers have the following drawbacks: due to their high gloss, they have an artificial sheen and are difficult to replicate the natural appearance of human hair.

[0009] The present invention was made in view of such circumstances and aims to provide a synthetic hair fiber with reduced gloss.

[0010] Through dedicated research, the inventors discovered that by setting a specific hollow structure in the fibers used for artificial hair, the aforementioned problems can be solved, thus completing this invention.

[0011] According to the present invention, the following content is provided.

[0012] [1] A synthetic hair fiber having a plurality of hollow portions extending along its length.

[0013] [2] According to [1], the artificial hair fiber, wherein, among the plurality of hollow portions, the first hollow portion is located approximately at the center of the fiber cross section perpendicular to the length direction of the artificial hair fiber, and among the plurality of hollow portions, one or more second hollow portions are respectively located in the fiber cross section further from the outer edge of the artificial hair fiber than the first hollow portion.

[0014] [3] According to [1], the artificial hair fiber, wherein, among the plurality of hollow portions, the largest hollow portion occupies 5% to 50% of the area in the fiber cross section perpendicular to the length direction, and the other one or more hollow portions occupy an average of 0.1% to 4% of the area in the fiber cross section.

[0015] [4] According to [3], the largest hollow portion is located approximately at the center of the fiber cross section perpendicular to the length direction of the artificial hair fiber, and the other one or more hollow portions are located in the fiber cross section further from the outer edge of the artificial hair fiber than the largest hollow portion.

[0016] [5] The artificial hair fiber according to any one of [1] to [4], wherein, of the plurality of hollow fibers, the area of ​​the largest hollow portion in the fiber cross-section perpendicular to the length direction is set as S. M The sum of the areas of one or more hollow portions in the fiber cross-section is denoted as S. O At that time, S M / S O The range is 5 to 40.

[0017] [6] The artificial hair fiber according to any one of [1] to [5], wherein the outer edge length of the largest hollow portion in the fiber cross section perpendicular to the length direction is L. M The sum of the outer edge lengths of one or more hollow portions in the fiber cross-section is denoted as L. O At that time, L M / L O The value ranges from 1.3 to 3.8.

[0018] [7] The artificial hair fiber according to any one of [1] to [6], wherein the shortest distance between the outer edges of adjacent hollow portions in the plurality of hollow portions is 3 μm to 30 μm.

[0019] [8] The artificial hair fiber according to any one of [2] to [7], wherein the fiber cross section has at least one of an inner protrusion protruding toward one of the plurality of hollow portions by one or more other hollow portions, and an outer protrusion protruding toward the outer edge of the artificial hair fiber by one or more of the plurality of hollow portions.

[0020] [9] The artificial hair fiber according to any one of [1] to [8], wherein the number of the plurality of hollow portions is three or more.

[0021]

[10] The artificial hair fiber according to any one of [1] to [9] contains a vinyl chloride resin.

[0022]

[11] A hair decoration product comprising any one of the artificial hair fibers described in [1] to

[10] .

[0023]

[12] The hair ornament product according to

[11] includes braids.

[0024] According to the present invention, it is possible to provide a synthetic hair fiber with reduced gloss. Attached Figure Description

[0025] Figure 1 The diagram shows a cross-sectional view of the fiber section perpendicular to the length direction of the artificial hair fiber according to the first embodiment.

[0026] Figure 2 shows a cross-sectional view of the fiber section perpendicular to the length direction of the artificial hair fiber in one embodiment of the present invention. Regarding the shape of the fiber cross-section of the artificial hair fiber, Figure 2A It is a two-leaf shape with two C-shaped joints. Figure 2B It is a 3-lobed shape with 3 C-shaped joints. Figure 2C It is roughly a triangle. Figure 2D It is roughly quadrilateral.

[0027] Figure 3 shows a cross-sectional view of the fiber section perpendicular to the length direction of the artificial hair fiber in one embodiment of the present invention. Figure 3A This shows a synthetic hair fiber that has neither an inner nor an outer protrusion. Figure 3B This shows artificial hair fibers with only the outer protrusion. Figure 3C This illustrates a synthetic hair fiber that simultaneously possesses both an inner protrusion and an outer protrusion.

[0028] Figure 4 This is an enlarged photograph of the cross-section of a fiber for artificial hair, according to one embodiment. Detailed Implementation

[0029] The present invention will now be described in detail. However, the present invention is not limited to these descriptions. The technical features of the embodiments shown below can be combined with each other. Furthermore, each technical feature can independently constitute the present invention.

[0030] <Terminology Explanation>

[0031] In this specification, for example, the designation "X~Y" means above X and below Y.

[0032] 1. Fibers for artificial hair

[0033] 1.1 Shape of fibers for artificial hair

[0034] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification and the drawings, components labeled with the same symbols are assumed to have substantially the same structure or function. Furthermore, for ease of understanding, the scale of the drawings may differ from the actual scale.

[0035] 1.1.1 First Implementation Method

[0036] Figure 1 The diagram shows a cross-sectional view of the fiber section (hereinafter referred to as "fiber section") perpendicular to the length direction of the artificial hair fiber 10 according to this embodiment. Figure 1 As shown, the artificial hair fiber 10 according to this embodiment has four hollow portions 20 (one 20A and three 20B) extending along its length. More specifically, the artificial hair fiber 10 has a hollow portion 20A and a solid portion 30 covering it. Furthermore, the solid portion 30 has three hollow portions 20B. In this specification, "hollow portion" refers to a portion that is continuously present for 10 cm or more along the length of the artificial hair fiber 10 and has a major diameter of 3 μm or more in the fiber cross-section. The artificial hair fiber 10 according to this embodiment, having hollow portions 20, is lightweight, allowing for the creation of hairstyles with desired volume with less wear, enabling a wide range of hairstyles, including long hairstyles with a substantial feel. It also reduces damage to one's own hair and scalp, and offers numerous advantages such as reduced waste and environmental impact.

[0037] According to the hollow portion 20 of this embodiment, such as Figure 1As shown, hollow portion 20A is located approximately at the center of the fiber cross-section, and other hollow portions 20B are located in the fiber cross-section further from the outer edge 11 of the artificial hair fiber 10 than hollow portion 20A (hereinafter, the hollow portion 20 located approximately at the center of the fiber cross-section is referred to as the "first hollow portion," and the hollow portions 20 located further from the outer edge of the fiber cross-section than the first hollow portion are specifically referred to as the "second hollow portion"). Here, "hollow portion located approximately at the center of the fiber cross-section" means that the center of the fiber cross-section is located within the hollow portion. By arranging the hollow portions 20 of the artificial hair fiber 10 in this way, the luster of the artificial hair fiber bundle is reduced, presenting a natural appearance.

[0038] The outer edge shape of the fiber cross-section of the artificial hair fiber 10 according to this embodiment is circular, but it is not particularly limited. Figures 2 and 3 show examples of the fiber cross-section of the artificial hair fiber 10 according to one aspect of the present invention. The outer edge shape of the fiber cross-section can be selected from circular (… Figure 1 and Figure 3A ), oval and roughly circular ( Figure 3B and Figure 3C ), a two-leaf shape joined by two C-shaped joints ( Figure 2A ), a 3-lobed shape with 3 C-shaped joints ( Figure 2B ) and multi-leaf shapes with four or more C-shaped joints, and roughly triangular shapes ( Figure 2C ), roughly square ( Figure 2D ) and any of the approximate polygons.

[0039] The major diameter M1 of the artificial hair fiber 10 in this embodiment is preferably 30 to 300 μm in the fiber cross-section, more preferably 50 to 150 μm. The major diameter M1 in the fiber cross-section can be, for example, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 μm, or a range between any two values ​​exemplified herein. If the major diameter M1 of the artificial hair fiber 10 in the fiber cross-section is within such a range, the tactile feel of the artificial hair fiber bundle is improved, and it presents a natural appearance.

[0040] According to this embodiment, the hollow portion 20A of the fiber cross-section is approximately circular, and the hollow portion 20B is circular, but the shape of the hollow portion 20 in the fiber cross-section is not particularly limited. The shape of the hollow portion 20 in the fiber cross-section can be selected from circular (…). Figure 1 To the hollow section 20B in Figure 3, Figure 3A Hollow section 20A and Figure 3B Hollow part 20A), roughly circular ( Figure 1 Hollow section 20A and Figure 3C Hollow part 20A), elliptical and roughly elliptical, 2-lobed shape ( Figure 2A Hollow part 20A), 3-leaf shape ( Figure 2B The hollow part 20A) and the multi-leaf shape, and the roughly triangular shape ( Figure 2C Hollow part 20A), roughly quadrilateral ( Figure 2D The hollow portion 20A) and the generally polygonal shape are both possible. In the hollow portion 20, the shape of the fiber cross section of one or more hollow portions 20 (hollow portion 20B in this embodiment, excluding the largest hollow portion) is preferably an elongated generally elliptical or an elongated generally polygonal shape.

[0041] According to this embodiment, the major diameter M2 of the largest hollow portion (hollow portion 20A in this embodiment) in the fiber cross-section is preferably 10 to 200 μm, more preferably 20 to 100 μm. The major diameter M2 of the largest hollow portion in the fiber cross-section can be, for example, 10, 11, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, or 200 μm, or a range between any two values ​​exemplified here. If the major diameter M2 of the largest hollow portion in the fiber cross-section is within such a range, the fiber bundle for artificial hair exhibits excellent lightweight properties and ensures sufficient structural retention.

[0042] According to this embodiment, the major diameter M3 of one or more hollow portions (hollow portions excluding the largest hollow portion, referred to as hollow portion 20B in this embodiment) in the fiber cross-section is preferably 3 to 30 μm, more preferably 5 to 15 μm. The major diameter M3 of one or more hollow portions (hollow portions excluding the largest hollow portion, referred to as hollow portion 20B in this embodiment) in the fiber cross-section can be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm, or a range between any two values ​​exemplified herein. If the major diameter M3 of one or more hollow portions (excluding the largest hollow portion) in the fiber cross-section is within such a range, sufficient structural retention of the fiber bundle for artificial hair can be ensured, and the gloss is reduced, resulting in a natural appearance.

[0043] In the hollow portion 20 according to this embodiment, the largest hollow portion (hollow portion 20A in this embodiment) preferably occupies 5 to 50% of the area in the fiber cross-section. The largest hollow portion may occupy, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% of the area in the fiber cross-section, or a range between any two values ​​illustrated herein. If the area ratio of the largest hollow portion in the fiber cross-section is within such a range, the fiber bundle for artificial hair exhibits excellent lightweight properties and ensures sufficient structural retention. Furthermore, the area ratio of the hollow portion 20 in the fiber cross-section can be calculated using the following formula.

[0044] (Area ratio of hollow portion 20 in fiber cross section) = {(Area surrounded by outer edge 21 of hollow portion 20) / (Area surrounded by outer edge 11 of artificial hair fiber 10)} × 100

[0045] The area enclosed by the outer edge 11 of the artificial hair fiber 10 refers to the cross-sectional area of ​​the artificial hair fiber 10 when it does not have a hollow portion 20.

[0046] The area ratio of the hollow portion 20 in the fiber cross section can be determined by cutting the artificial hair fiber 10 along a direction perpendicular to its length, observing the cut surface with a laser microscope or scanning electron microscope, and performing image analysis. Specifically, it can be determined by the method described in the embodiment.

[0047] In the hollow portion 20 according to this embodiment, one or more hollow portions other than the largest hollow portion (hollow portion 20B in this embodiment) preferably occupy an average area of ​​0.1% to 4% of the fiber cross-section. The average area occupied by one or more hollow portions other than the largest hollow portion in the fiber cross-section may be, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, or 4%, or may be within any range of two values ​​exemplified herein. If one or more hollow portions other than the largest hollow portion occupy such an area in the fiber cross-section, the luster of the artificial hair fiber bundle is reduced, resulting in a more natural appearance.

[0048] In this embodiment, hollow portion 20A is the largest hollow portion and is located approximately at the center of the fiber cross-section. Furthermore, hollow portions 20B are all hollow portions other than the largest hollow portion, and are located in the fiber cross-section further along the outer edge 11 of the artificial hair fiber 10 than hollow portion 20A. Thus, it is preferable that the largest hollow portion in the hollow portions 20 is the first hollow portion, and one or more hollow portions other than the largest hollow portion are the second hollow portions. With such a structure for the hollow portions 20, the structure can be maintained even when used for gear processing, etc.

[0049] In the hollow section 20 according to this embodiment, the area in the fiber cross-section of the largest hollow section (hollow section 20A in this embodiment) is S. M Let S be the sum of the areas in the fiber cross-sections of one or more other hollow portions (hollow portion 20B in this embodiment). O At that time, S M / S O Preferably, it is 5 to 40. Alternatively, S can be... M and S O S is calculated by replacing each value with the area ratio of the largest hollow portion in the fiber cross-section and the sum of the area ratios of one or more other hollow portions in the fiber cross-section. M / S O S M / S O For example, it can be 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, or 40, or it can be a range between any two values ​​listed here. If S M / S O With such a value, the structure of the artificial hair fiber 10 is well maintained, and the luster of the artificial hair fiber bundle is reduced, resulting in a natural appearance.

[0050] In this embodiment, the length of the outer edge 21 of the fiber cross-section of the largest hollow section (hollow section 20A in this embodiment) is L. M Let L be the sum of the lengths of the outer edges 21 in the fiber cross-sections of one or more other hollow portions (hollow portion 20B in this embodiment). O At that time, L M / L O Preferably, it is 1.3 to 3.8 L. M / L O For example, it can be 1.3, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, or 3.8, or it can be a range between any two values ​​listed here. If L M / L O With such a value, the structure of the artificial hair fiber 10 is well maintained, and the luster of the artificial hair fiber bundle is reduced, resulting in a natural appearance.

[0051] The length of the outer edge 21 of the hollow portion 20 in the fiber cross section can be determined by cutting the artificial hair fiber 10 along a direction perpendicular to its length, observing the cut surface with a laser microscope or scanning electron microscope, and performing image analysis. Specifically, it can be determined by the method described in the embodiment.

[0052] According to this embodiment, the shortest distance D between the outer edges 21 of adjacent hollow portions 20 is preferably 3 to 30 μm. The shortest distance D can be, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm, or a range between any two values ​​exemplified herein. If the lower limit of the shortest distance D is such a value, the structural retention of the artificial hair fiber 10 is excellent. Furthermore, if the upper limit of the shortest distance D is such a value, the lightweight nature of the artificial hair fiber 10 is excellent.

[0053] The shortest distance D of the outer edge 21 of the hollow part 20 can be determined by cutting the artificial hair fiber 10 along a direction perpendicular to its length, observing the cut surface with a laser microscope or scanning electron microscope and performing image analysis. Specifically, it can be determined by the method described in the embodiment.

[0054] The artificial hair fiber 10 according to this embodiment also has an inner protrusion 22 in its cross-section, which protrudes into one of the plurality of hollow portions 20A by the other plurality of hollow portions 20B. Thus, it is preferable to provide an inner protrusion 22 that protrudes into one of the plurality of hollow portions 20 by one or more other hollow portions 20. Furthermore, FIG3 shows a cross-sectional view of the fiber cross-section perpendicular to the length direction of the artificial hair fiber 10 according to another embodiment. Figure 3A As shown, an embodiment that lacks neither the inner protrusion 22 nor the outer protrusion 24 (described later) is also an embodiment of this application. On the other hand, as... Figure 3B As shown, according to another embodiment, the artificial hair fiber 10 has an outer protrusion 24 in its cross-section, which protrudes toward the outer edge 11 of the artificial hair fiber 10 from a plurality of hollow portions 20B. Figure 3CAs shown, according to another embodiment, the artificial hair fiber 10 has an inner protrusion 22 protruding into one of the plurality of hollow portions 20A from the other plurality of hollow portions 20B in the fiber cross-section, and an outer protrusion 24 protruding into the outer edge 11 of the artificial hair fiber 10 from the plurality of hollow portions 20B. Thus, it is preferable to have an outer protrusion 24 protruding into the outer edge 11 of the artificial hair fiber 10 from one or more of the plurality of hollow portions 20 in the fiber cross-section. In the fiber cross-section, it is preferable to have at least one of the inner protrusion 22 and the outer protrusion 24. If the artificial hair fiber 10 has such a structure, the structure retention is excellent. Furthermore, from the viewpoint of improving the tactile feel of the artificial hair fiber 10, the size and frequency of the outer protrusion 24 are preferably lower, preferably the outer protrusion 24 is smaller or less frequent than the inner protrusion 22, and more preferably only the inner protrusion 22 is provided.

[0055] The number of hollow portions 20 according to this embodiment is four, but it is not particularly limited as long as there are two or more. The number of hollow portions 20 can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15, or it can be a range between any two values ​​exemplified here. If the lower limit of the number of hollow portions 20 is such a value, the luster of the fiber bundle for artificial hair is reduced, presenting a natural appearance. If the upper limit of the number of hollow portions 20 is such a value, the structural retention of the fiber 10 for artificial hair is excellent.

[0056] Next, a variation of the artificial hair fiber 10 of the above embodiment will be described. In the artificial hair fiber 10 according to this embodiment, the plurality of hollow portions 20 extending along the length direction may all have the same dimensions (major diameter, area occupied in the fiber cross-section). Furthermore, the "largest hollow portion" can be any one of these. Additionally, in the artificial hair fiber 10 according to this embodiment, the largest hollow portion among the hollow portions 20 extending along the length direction may not be located approximately at the center. Such an artificial hair fiber 10 is also an embodiment of the present invention.

[0057] 1.2 Composition

[0058] The resin composition of the artificial hair fiber 10 constituting this embodiment is not particularly limited, and may include at least one of polyamide resins, polyester resins, vinyl chloride resins, AS resins (acrylonitrile-styrene resins), PP resins, PET resins, PE resins, PAN resins, and PLA resins (polylactic acid resins). From the viewpoint of easily obtaining the die swell effect described later, the artificial hair fiber 10 according to this embodiment preferably contains a vinyl chloride resin. Furthermore, the artificial hair fiber 10 according to this embodiment preferably contains both a vinyl chloride resin and an AS resin.

[0059] The polyvinyl chloride (PVC) resin according to this embodiment may comprise a PVC polymer containing monomer units (vinyl chloride monomer units) derived from vinyl chloride monomer. The PVC resin according to the present invention may comprise a homopolymer formed by homopolymerizing vinyl chloride monomer, and / or a copolymer containing monomer units derived from vinyl chloride monomer and other monomers that can copolymerize with vinyl chloride monomer. Examples of copolymers include: vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl propionate copolymers, and other copolymers of vinyl chloride with vinyl esters; vinyl chloride-ethylene copolymers, vinyl chloride-propylene copolymers, and other copolymers of vinyl chloride with olefins; and vinyl chloride-acrylonitrile copolymers. Furthermore, the PVC resin according to this embodiment may be composed of one PVC polymer, or may contain two or more PVC polymers.

[0060] The resin composition constituting the artificial hair fiber 10 of this embodiment contains 50 to 99% by mass of a vinyl chloride-based resin in 100% by mass of the resin composition, preferably 65 to 95% by mass, and more preferably 65 to 90% by mass. Specifically, it may be, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99% by mass, or it may be a range between any two values ​​exemplified herein.

[0061] As-based resins (acrylonitrile-styrene resins) are copolymers containing styrene monomer units and acrylonitrile monomer units, and may also contain other monomer units that can be copolymerized with them, as needed. As-based resins contain, for example, 60, 65, 70, 75, 80, 85, or 90% by mass of styrene monomer units relative to 100% by mass of the AS resin, or any range between any two values ​​exemplified herein. As-based resins contain, for example, 10, 15, 20, 25, 30, 35, or 40% by mass of acrylonitrile monomer units relative to 100% by mass of the AS resin, or any range between any two values ​​exemplified herein.

[0062] The artificial hair fiber 10 according to this embodiment may also contain other components as needed. These other components include antistatic agents, heat stabilizers, lubricants, colorants, processing aids, plasticizers, reinforcing agents, ultraviolet absorbers, antioxidants, fillers, flame retardants, pigments, initial color improvers, conductivity imparting agents, and fragrances.

[0063] 1.3 Method for manufacturing fibers for artificial hair

[0064] The method for manufacturing artificial hair fiber 10 according to this embodiment includes a resin composition preparation process for artificial hair fiber and a spinning process, and may also include a stretching process, a heat treatment process, and a gear processing process.

[0065] 1.3.1 Preparation process of resin composition for artificial hair fibers

[0066] In the process of preparing a resin composition for artificial hair fibers, a resin-containing raw material is mixed to obtain the resin composition for artificial hair fibers. Here, the raw material includes a base resin, and other components may be included as needed.

[0067] The mixing method is not particularly limited and can be any conventionally known method. For example, a powdered resin composition (powder mixture) can be obtained using known mixing equipment such as a Henschel mixer, a super mixer, and a belt mixer. Melting and mixing the powder mixture yields a granular resin composition (granular mixture). The powder mixture can be manufactured using either hot or cold mixing. As an example, to reduce the volatile matter from the resin composition, the discharge temperature during mixing can be set to 105–155°C for hot mixing. The granular mixture can be manufactured using the same method as for general polyvinyl chloride (PVC) resin granular mixtures. For example, a single-screw extruder, a counter-rotating twin-screw extruder, a conical twin-screw extruder, a co-rotating twin-screw extruder, a co-kneader, a planetary gear extruder, or a roller mixer can be used to produce the granular mixture. The conditions for manufacturing the granular mixture are not particularly limited, but to prevent thermal degradation of the resin composition, it is preferable to set the resin temperature below 185°C. In addition, a filter screen can be installed near the front end of the screw to remove any small amounts of screw metal fragments that may mix into the pellet mixture or fibers that may adhere to protective gloves. Pellet production can be achieved using a cold-cutting method. Alternatively, methods can be used to remove cutting dust (fine powder generated during pellet production) that may be mixed in during cold cutting. Furthermore, if used for extended periods, the cutting edge of the cutter is prone to wear and tear, easily generating cutting dust; therefore, timely replacement is preferable.

[0068] 1.3.2 Spinning process

[0069] In the spinning process, the aforementioned resin composition for artificial hair fibers is melt-spun to obtain artificial hair fibers 10. As an example, the aforementioned resin composition (e.g., a granular mixture) can be extruded from a heated barrel through a nozzle and melt-spun. Conventionally known extruders can be used as the extruder, such as single-screw extruders, counter-rotating twin-screw extruders, and conical twin-screw extruders.

[0070] The melt spinning conditions can be appropriately set according to the type of resin composition, so that the resin melts and forms the hollow portion 20B. For example, the barrel temperature can be set to 150–190°C, and the nozzle temperature can be set to 155–195°C. Furthermore, the extrusion speed is preferably 5–20 kg / h, more preferably 8–18 kg / h. When the temperature and extrusion speed are within this range, it is easy to form the hollow portion 20B, and the size is suitable.

[0071] Undrawn yarn melt-spun from the nozzle is fed into a heated cylinder (e.g., heated cylinder temperature 250°C) for instantaneous heat treatment and then wound up by a winding machine located directly below the nozzle (e.g., about 4.5m).

[0072] The nozzle used for melt extrusion of the artificial hair fiber 10 in this embodiment can be appropriately selected according to the shape, hollowness, number of hollows, and size of the artificial hair fiber 10 to be obtained.

[0073] As an example, in manufacturing Figure 1 In the case of the artificial hair fiber 10 shown in Figure 3, which has a circular or approximately circular cross-section and three hollow portions 20B, a nozzle with three shallow C-shaped nozzle holes can be used; in manufacturing such... Figure 2A In the case of the artificial hair fiber 10 shown, which has a two-leaf-shaped cross-section and two hollow portions 20B, a nozzle with two deep C-shaped nozzle holes can be used; in manufacturing such as Figure 2B In the case of the artificial hair fiber 10 shown, which has a three-lobed cross-section and three hollow portions 20B, a nozzle with three deep C-shaped nozzle holes can be used. Furthermore, in manufacturing such... Figure 2C In the case of the artificial hair fiber 10 shown, which has a roughly triangular cross-section and three hollow portions 20B, a nozzle with three rod-shaped nozzle holes can be used; in manufacturing such... Figure 2DIn the case of the artificial hair fiber 10 shown, which has a generally quadrangular cross-section and four hollow portions 20B, a nozzle with four rod-shaped nozzle holes can be used. Thus, the number of nozzle holes can be set based on the number of hollow portions 20B located further towards the outer edge 11 of the artificial hair fiber 10 than the hollow portion 20A located approximately at the center, or the number of hollow portions 20 located near the outer edge 11 of the artificial hair fiber 10 (in other words, the solid portion 30). Furthermore, due to the separation between the nozzle holes, at least a portion of the resin composition is broken during melt extrusion, but after exiting from the nozzle holes, the resin composition contacts and fuses with each other to form hollow portions 20. Furthermore, in one embodiment of the invention, the resin composition exiting from the nozzle holes can expand through a die swell effect, forming inner protrusions 22 and / or outer protrusions 24.

[0074] 1.3.4 Stretching and heat treatment processes

[0075] The manufacturing method of the artificial hair fiber 10 according to an embodiment of the present invention may also include a stretching process and a heat treatment process.

[0076] In the stretching process, the unstretched artificial hair fiber 10 obtained in the melt spinning process can be stretched using a stretching machine to obtain the stretched artificial hair fiber 10. As an example, in the stretching process, the unstretched artificial hair fiber 10 can be stretched by 2 to 5 times, for example, in an air atmosphere at 90 to 110°C.

[0077] Furthermore, in the heat treatment process, a heat treatment machine can be used to heat treat the stretched artificial hair fiber 10. As an example, in the heat treatment process, the stretched artificial hair fiber 10 can be heat-treated in an air atmosphere at 90 to 110°C at a temperature of 0.5 to 0.99 times its original value, causing the fiber to shrink thermally along its entire length, thereby obtaining the heat-treated artificial hair fiber 10 with the desired fineness.

[0078] 1.3.5 Gear Machining Process

[0079] The method for manufacturing artificial hair fiber 10 according to this embodiment may also include a gear processing step.

[0080] In the gear processing step, the fiber bundle can be crimped by passing it between two meshing, high-temperature gears. There are no particular limitations on the material, waveform, or number of teeth of the gears used in the gear processing step. In the gear processing step, considering the fiber material and fineness, the shape of the resulting artificial hair fiber 10 can be controlled by appropriately adjusting the groove depth of the gear waveform, the surface temperature of the gear, the processing speed, and the pressure conditions between the gears. These processing conditions are not particularly limited; for example, the groove depth of the gear waveform can be set to 0.2–6 mm, preferably 0.5–5 mm; the surface temperature of the gear can be set to 30–100°C, preferably 40–80°C; and the processing speed can be set to 0.5–10 m / min, preferably 1.0–8.0 m / min.

[0081] The method for manufacturing artificial hair fiber 10 according to an embodiment of the present invention may also include other steps, such as a surface treatment agent attachment step.

[0082] In addition, in this invention, the artificial hair fiber 10 includes the artificial hair fiber 10 after spinning, and includes the artificial hair fiber 10 before the stretching process, after the stretching process, before the heat treatment process, after the heat treatment process, before the gear processing process, and after the gear processing process.

[0083] 2. Fiber bundles for artificial hair

[0084] According to this embodiment, the artificial hair fiber bundle includes the aforementioned artificial hair fiber 10. Preferably, the artificial hair fiber bundle is composed of the aforementioned artificial hair fiber 10.

[0085] In addition, the following parameters are specified in the fiber bundle for artificial hair: "major diameter M1 of the artificial hair fiber in the fiber cross-section", "major diameter of the hollow portion in the fiber cross-section", "area ratio of the hollow portion in the fiber cross-section", "outer edge length of the hollow portion in the fiber cross-section", "number of hollow portions", and "S". M / S O “L” M / L O "" refers to the average value of the artificial hair fibers 10 contained. These values ​​may be, for example, the average value of observations based on fiber cross-sections with an N number of 30.

[0086] 2.1 Looseness

[0087] According to this embodiment, the bulkiness (specific volume) of the fiber bundle for artificial hair is preferably 5 cc / g or more, and more preferably 9 cc / g or more. The bulkiness may be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 cc / g, or may be a range between any two values ​​exemplified herein.

[0088] 2.2 Gloss

[0089] According to this embodiment, the gloss of the fiber bundle for artificial hair is preferably 6.6 or less, more preferably 6.5 or less, and more preferably 6.2 or less. The lower limit value of the fiber bundle for artificial hair according to this embodiment is not particularly limited, for example, it is 4.0. The gloss can be, for example, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, or 6.6, or a range between any two values ​​exemplified herein. The gloss can be measured using a photometer, specifically using the method described in the examples.

[0090] 2.3 Appearance

[0091] According to this embodiment, the fiber bundles for artificial hair preferably have a good appearance. A good appearance means that, in terms of hue and luster, they have a natural deviation similar to human hair. The appearance of the fiber bundles for artificial hair can be evaluated visually by an artificial hair fiber processing technician (with more than 5 years of practical experience).

[0092] 2.3 Structural Integrity

[0093] According to this embodiment, the structural retention rate of the fiber cross-section of the artificial hair fiber 10 is preferably 90% or higher. The structural retention rate can be, for example, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%, or a range between any two values ​​exemplified herein. The structural retention rate represents the proportion of artificial hair fibers 10 with a cross-section where the hollow portion 20 is entirely covered by the solid portion 30 and the hollow portion 20 does not collapse. Specifically, it can be calculated using the method described in the embodiment, for example, based on observations of fiber cross-sections with an N value (sample size) of 300, according to the following formula.

[0094] Structural retention rate = (300 - ij) / 300

[0095] i: The number of fibers having one or more hollow portions 20 that are not entirely covered by the solid portion 30

[0096] j: The number of fibers in contact with each other in the hollow section.

[0097] "Fibers with hollow portions not completely covered by solids" refers to, for example, fibers with a circular outer edge shape but a C-shaped cross-section, where a portion is separated.

[0098] 3 Hair styling products

[0099] According to this embodiment, the hair-decorative product includes the aforementioned artificial hair fibers. Furthermore, according to one embodiment of the present invention, the hair-decorative product includes the aforementioned artificial hair fiber bundles.

[0100] According to this embodiment, the artificial hair fiber bundle can be used in hair decoration products. Examples of hair decoration products include wigs, hairpieces, braids, hair extensions, doll hair, hairpieces, partial wigs, headbands, etc. The hair decoration products obtained from the artificial hair fiber bundle according to this embodiment have a color and luster similar to human hair, presenting a natural appearance.

[0101] Furthermore, the headwear product obtained from the fiber bundle of artificial hair according to the embodiments of the present invention is lightweight because the hollow structure of each fiber is maintained with a high probability. It can create a hairstyle with the desired volume and fluffiness with a small amount of wear, and can achieve a wide range of hairstyles, including long hairstyles with a sense of weight. It can reduce damage to one's own hair and scalp, and brings many advantages such as reducing waste and environmental impact.

[0102] The headdress product according to an embodiment of the present invention, having the above-described features, is applicable to various styles, and is particularly suitable for braids including three-strand braids or twisted braids.

[0103] Example

[0104] The present invention will now be described in more detail based on embodiments. Furthermore, the embodiments described below are merely one example of representative embodiments of the present invention, and the scope of the present invention should not be narrowly interpreted as such.

[0105] (Example 1)

[0106] <Preparation Process of Resin Composition for Fibers in Artificial Hair>

[0107] 70 parts by weight of polyvinyl chloride resin (manufactured by Taiyo Polyvinyl Chloride Co., Ltd., product name: TH1000), 30 parts by weight of vinyl copolymer resin (manufactured by Denka Co., Ltd., GR-AT-6S) with 68% by weight of styrene monomer units and 32% by weight of acrylonitrile monomer units, 5 parts by weight of additives including plasticizer, stabilizer, and lubricant (specifically: 3 parts by weight of stabilizer composition, 1 part by weight of epoxidized soybean oil, 0.4 parts by weight of phosphorus chelating agent, and 0.6 parts by weight of polyethylene wax), and 0.5 parts by weight of carbon black were mixed in a mixer. The mixed material was then compounded using a φ40mm single-screw extruder to obtain a granular resin composition for artificial hair fibers used in spinning.

[0108] The components and composition of the stabilizer composition used to obtain the resin composition are as follows.

[0109] • Hydrotalcite compound (Mg4Al2(OH) 12 CO3·3H2O) 72.6 parts by mass

[0110] · Zinc stearate 13.1 parts by weight

[0111] • Silica (manufactured by DSL.Japan Co., Ltd., "Carplex (registered trademark) #80") 2.2 parts by weight

[0112] · 2.3 parts by weight of dibenzoylmethane

[0113] 0.9 parts by weight of dipentaerythritol

[0114] • Vinyl chloride resin (manufactured by Taiyo PVC Co., Ltd., product name: TH1000) 8.9 parts by weight

[0115] Other additives used to obtain the resin composition are as follows.

[0116] • Epoxidized soybean oil: Manufactured by ADEKA Co., Ltd., "ADEKA CIZER (registered trademark) O-130P"

[0117] • Phosphorus-based chelating agent: "ADEKA STAB (registered trademark) 1030" manufactured by ADEKA Co., Ltd.

[0118] • Polyethylene wax: Manufactured by Mitsui Chemicals Co., Ltd.

[0119] <Spinning Process>

[0120] The obtained granular resin composition for artificial hair fibers was spun using a φ40mm single-screw melt spinning machine. The number of nozzles and extrusion speed are shown in Table 1. Undrawn filaments were produced from the molten resin discharged from the nozzles. The spinneret barrel temperature was set to 180°C, and the nozzle temperature was set to 190°C.

[0121] <Stretching and heat treatment processes>

[0122] The obtained undrawn yarn was stretched at 100°C and then annealed at 100–200°C to obtain fibers for artificial hair. The draw ratio was 3 times, and the relaxation rate during annealing was set to 0.5–0.99 times. The relaxation rate during annealing was calculated as (rotation speed of the take-up roller during annealing) / (rotation speed of the feed roller during annealing).

[0123] (Examples 2-8, Comparative Example 1)

[0124] By changing the nozzles used in the spinning process, as well as the conditions of the spinning, stretching, and heat treatment processes, artificial hair fibers with different sizes and numbers of hollow sections were obtained. The artificial hair fibers of the examples and comparative examples thus produced were subjected to tests and evaluations described later, and the results are shown in Table 1.

[0125] <Observation of fiber cross-section>

[0126] First, multiple strands of artificial hair fibers, cut into appropriate lengths, are wound with vinyl tape. Then, the fiber bundles are cut perpendicular to their length using a utility knife to create a cross-section. A laser microscope is used to photograph the cross-section of the fibers at 400x magnification. Figure 4 An enlarged photograph of the cross-section of the artificial hair fiber of Example 3 is shown. Figure 4 As shown, the artificial hair fibers obtained in each embodiment and comparative example all have a generally circular outer edge shape in their fiber cross-section. Furthermore, a largest hollow portion (i.e., the largest hollow portion is the first hollow portion) exists approximately at the center of the fiber cross-section, and other hollow portions are located further outward from the outer edge of the artificial hair fiber than the largest hollow portion (i.e., the other hollow portions are the second hollow portions). Moreover, in the fiber cross-section of each embodiment, an inner protrusion protrudes towards the largest hollow portion (the first hollow portion) from the other hollow portions (the second hollow portions).

[0127] Based on the obtained photographs of the fiber cross-section, the major diameter of the artificial hair fiber and its hollow portion, the number of hollow portions, the shortest distance between the outer edges of adjacent hollow portions, the area ratio of the hollow portion in the fiber cross-section, and the outer edge length of the hollow portion in the fiber cross-section were measured. Furthermore, the average values ​​were calculated using a VK-X150 controller manufactured by KEYENCE Co., Ltd., with an N value of 30.

[0128] In the various embodiments and comparative examples, the major diameter M1 of the artificial hair fibers obtained in the fiber cross-section is 50 to 150 μm. Furthermore, the major diameter M2 of the largest hollow portion (first hollow portion) in the fiber cross-section is in the range of 20 to 100 μm. Moreover, the major diameter M3 of the hollow portion other than the largest hollow portion (second hollow portion) in the fiber cross-section is in the range of 5 to 15 μm.

[0129] <fluidity>

[0130] Using artificial hair fibers cut into 120cm sections, prepare a 120g bundle of artificial hair fibers. Fold this bundle 60cm in length and place it inside a 39.5mm wide partition. Then, measure the height of the sample and calculate the specific volume based on the following formula.

[0131] The specific volume (cc / g) is calculated as follows: (width of the partition × length of the sample × height of the sample) ÷ fiber mass.

[0132] <Glossiness>

[0133] Artificial hair fiber bundles were prepared using artificial hair fibers cut to appropriate lengths. The luster of each artificial hair fiber bundle was measured using the following apparatus and under the following conditions.

[0134] Apparatus: Murakami Color Technology Research Institute Co., Ltd. GP-700 Variable Angle Photometer

[0135] Angle of incidence: 45°

[0136] Sensitivity adjustment knob value (COARSE): 906

[0137] Sensitivity adjustment knob value (FINE): 737

[0138] <Appearance>

[0139] The appearance was assessed by visually evaluating 250mm long and 20g artificial hair fiber bundles (from the Examples and Comparative Examples) by 10 artificial hair fiber processing technicians (with over 5 years of practical experience) according to the following evaluation criteria. Furthermore, a good appearance refers to a natural deviation in hue and luster, similar to human hair.

[0140] A: More than 9 technicians rated the appearance as good.

[0141] B: 6-8 technicians rated the appearance as good.

[0142] C: 3-5 technicians rated the appearance as good.

[0143] D: For technical personnel of 2 or fewer, the appearance is rated as good.

[0144] <Structural Preservation>

[0145] Similar to the observation of fiber cross-sections described above, the fiber cross-sections were photographed at 400x magnification using a laser microscope. The structural retention rate was then calculated based on the following formula, with N=300.

[0146] Structural retention rate = (300 - ij) / 300

[0147] i: The number of fibers having one or more hollow portions 20 that are not entirely covered by the solid portion 30

[0148] j: The number of fibers in contact with each other in the hollow section.

[0149] "Fibers with hollow portions not completely covered by solids" refers to fibers whose cross-section is not circular but C-shaped, and which are partially separated.

[0150] Table 1

[0151]

[0152] Symbol Explanation

[0153] 10: Fiber for artificial hair, 11: Outer edge of fiber for artificial hair, 20: Hollow portion, 20A: Hollow portion located approximately at the center of the fiber cross-section, 20B: Hollow portion located closer to the outer edge of the fiber for artificial hair in the fiber cross-section compared to the hollow portion located approximately at the center, 21: Outer edge of the hollow portion, 22: Inner protrusion, 24: Outer protrusion, 30: Solid portion, M1: Major diameter of the fiber for artificial hair in the fiber cross-section, M2: Major diameter of hollow portion 20A in the fiber cross-section, M3: Major diameter of hollow portion 20B in the fiber cross-section.

Claims

1. A fiber for artificial hair, wherein, The artificial hair fiber has multiple hollow portions extending along its length.

2. The artificial hair fiber according to claim 1, wherein, The first hollow portion of the plurality of hollow portions is located approximately at the center of the fiber cross-section perpendicular to the length direction of the artificial hair fiber. One or more of the plurality of hollow portions are located in the fiber cross-section at a position closer to the outer edge of the artificial hair fiber than the first hollow portion.

3. The artificial hair fiber according to claim 1, wherein, The largest of the plurality of hollow sections occupies 5% to 50% of the area in the fiber cross-section perpendicular to the length direction. In addition, one or more hollow portions occupy an average area of ​​0.1% to 4% of the fiber cross-section.

4. The artificial hair fiber according to claim 3, wherein, The largest hollow portion is located approximately at the center of the fiber cross-section perpendicular to the length direction of the artificial hair fiber. The other one or more hollow portions are located in the fiber cross-section at a position closer to the outer edge of the artificial hair fiber than the largest hollow portion.

5. The artificial hair fiber according to claim 1, wherein, Let S be the area of ​​the largest hollow portion among the plurality of hollow portions in the fiber cross-section perpendicular to the length direction. M , The sum of the areas of one or more hollow portions in the fiber cross-section is denoted as S. O hour, S M / S O The range is 5 to 40.

6. The artificial hair fiber according to claim 1, wherein, Let L be the outer edge length of the largest hollow portion among the plurality of hollow portions in the fiber cross-section perpendicular to the length direction. M , The sum of the outer edge lengths of the fiber cross-sections in one or more hollow portions, excluding the above, is set as L. O hour, L M / L O The value ranges from 1.3 to 3.

8.

7. The synthetic hair fiber according to any one of claims 1 to 6, wherein, Among the plurality of hollow sections, the shortest distance between the outer edges of adjacent hollow sections is 3 μm to 30 μm.

8. The synthetic hair fiber according to any one of claims 2 to 6, wherein, The fiber cross-section includes at least one of an inner protrusion that protrudes toward one of the plurality of hollow portions and is located from one or more other hollow portions, and an outer protrusion that protrudes toward the outer edge of the artificial hair fiber and is located from one or more of the plurality of hollow portions.

9. The synthetic hair fiber according to any one of claims 1 to 6, wherein, The number of hollow sections is three or more.

10. The artificial hair fiber according to any one of claims 1 to 6, comprising a vinyl chloride-based resin.

11. A hair styling product comprising the artificial hair fibers according to any one of claims 1 to 6.

12. The hair accessory product according to claim 11, comprising a braid.

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