Artificial hair and method for manufacturing artificial hair

Abstract

The present invention provides a soft and voluminous artificial hair and a method for producing the artificial hair.　The artificial hair has fiber cords in which one or a plurality of fiber bundles are woven or spirally wound, each of the fiber bundles is a bundle of a plurality of fibers including first fibers and second fibers, a cross section orthogonal to the longitudinal direction of the fiber bundle has a core portion and a shell portion surrounding the core portion, the first fibers and the second fibers are mixed in the core portion, the shell portion is constituted of the second fibers, and the total area of voids in the shell portion in the cross section is greater than the total area of voids in the core portion in the cross section.

Description

Technical Field

[0001] The present invention relates to artificial hair and a method for manufacturing artificial hair.

Background Art

[0002] Conventionally, artificial hair fibers imitating human hair have been used as materials for headdress products such as wigs, wigs, extensions, and hair bands (for example, Patent Document 1). For example, Patent Document 1 discloses a fiber bundle for artificial hair using two types of artificial hair fibers, a polyester resin and a polyamide resin, as artificial hair fibers. According to Patent Document 1, the fiber bundle for artificial hair has good combability, tactile sensation, and gloss similar to human hair, and is excellent in curl setting property and flame retardancy.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, in some headdress products for women, a style with a random and voluminous volume may be preferred. However, the artificial hair using the fiber bundle for artificial hair of Patent Document 1 has no volume and has a regular, uniform, and unoriginal shape.

[0005] Therefore, an object of the present invention is to provide artificial hair having a fluffy and voluminous shape and a method for manufacturing the same.

Means for Solving the Problems

[0006] One aspect of the present invention for solving the above-mentioned problems is an artificial hair having a fiber cord in which one or more fiber bundles are woven together or wound in a spiral, wherein the fiber bundles are bundles of multiple fibers including first fibers and second fibers, the cross section perpendicular to the longitudinal direction of the fiber bundle has a core portion and a shell portion surrounding the core portion, the core portion is composed of a mixture of first fibers and second fibers, the shell portion is composed of second fibers, and the total area of ​​voids in the shell portion in the cross section is greater than the total area of ​​voids in the core portion in the cross section.

[0007] According to this pattern, the shape will be irregular, fluffy, and voluminous.

[0008] A preferred feature is that, in the cross-section, the ratio of the area of ​​the shell portion to the area of ​​the core portion of the fiber bundle is greater than the ratio of the mass of the second fiber to the mass of the first fiber.

[0009] A more preferred configuration is that the second fiber extends from the inside of the core portion through the gaps between adjacent first fibers to the shell portion.

[0010] A preferred feature is that the area of ​​the shell portion in the cross-section is larger than the area of ​​the core portion.

[0011] A preferred configuration is that the thinnest thickness of the shell portion in the cross-section is 0.1 mm or more.

[0012] In this context, "thinnest thickness" refers to the thickness of the thinnest part, and "thinnest thickness of the shell" refers to the thickness of the thinnest part of the area where the shell exists. In this context, "shell thickness" refers to the distance from the outer edge of the core to the outer edge of the shell.

[0013] A preferred configuration is that the first fiber is present in an amount of 20 parts by mass or more and 80 parts by mass or less relative to 100 parts by mass of the first fiber and the second fiber combined.

[0014] A preferred configuration is that the amount of the second fiber is 20 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the total of the first fiber and the second fiber.

[0015] Furthermore, one aspect of the present invention is a method for producing artificial hair, comprising a fiber cord forming step of bundling a plurality of fibers including a first fiber and a second fiber to form a fiber bundle, and braiding the fiber bundle or winding it around a rod-shaped body to form a fiber cord, and a heating step of heating the fiber cord at a heating temperature equal to or higher than the softening temperature of the first fiber, wherein the first fiber has a thermal shrinkage rate of 10% or more when heated at the heating temperature for 10 minutes or more and 90 minutes or less, and the second fiber has a thermal shrinkage rate of 5% or less when heated at the heating temperature for 10 minutes or more and 90 minutes or less.

[0016] In this context, "thermal shrinkage rate" refers to the rate of thermal shrinkage of an unprocessed fiber material before and after heating. The thermal shrinkage rate (%) is expressed as {(length before heating) - (length after heating)} / (length before heating) × 100. The same applies hereafter. In this context, "softening temperature" refers to the temperature at which thermal shrinkage of 5% occurs. The same applies hereafter.

[0017] According to this pattern, the first fiber, which has a high thermal shrinkage rate, shrinks when heated during the heating process, and the second fiber, which has a relatively lower thermal shrinkage rate compared to the first fiber, is squeezed by the shrinkage of the first fiber and bulges outwards, resulting in an irregular, fluffy, and voluminous shape.

[0018] A preferred feature is that the softening temperature of the second fiber is 60°C or more higher than the softening temperature of the first fiber.

[0019] A preferred configuration is when the difference between the thermal shrinkage rate of the first fiber and the thermal shrinkage rate of the second fiber, when heated at the aforementioned heating temperature for 10 minutes or more and 90 minutes or less, is 15% or more.

[0020] A preferred aspect is that the heating temperature is below the softening temperature of the second fiber.

[0021] A preferred aspect is that the total length of the fiber bundle after the heating step is 0.2 times or more and 0.7 times or less the total length of the fiber bundle before the heating step.

[0022] A preferred aspect is that in the heating step, the fiber bundle is heated for 15 minutes or more and 2 hours or less.

[0023] A preferred aspect is that the second fiber is 20 parts by mass or more and 80 parts by mass or less with respect to a total of 100 parts by mass of the first fiber and the second fiber.

[0024] A more preferred aspect is that the second fiber is 50 parts by mass or more with respect to a total of 100 parts by mass of the first fiber and the second fiber.

[0025] A preferred aspect is that the first fiber is a polyvinyl chloride-based fiber.

[0026] A preferred aspect is that the second fiber is a polyester-based fiber, an acrylic-based fiber, or a nylon-based fiber.

Advantages of the Invention

[0027] According to the artificial hair and the method for manufacturing the artificial hair of the present invention, compared with the prior art, it becomes fluffy and has a bulky shape.

Brief Description of the Drawings

[0028] [Figure 1] It is a front view schematically showing the artificial hair of the first embodiment of the present invention. [Figure 2] It is an explanatory view of the fiber bundle in FIG. 1, (a) is a front view of the fiber bundle, and (b) is an end view of the A-A cross section of the fiber bundle in (a). The boundary between the core part and the shell part is represented by a virtual line, and the second fiber is indicated by dots. [Figure 3] It is an explanatory view of the heating step of the artificial hair in FIG. 1, (a) is a front view before the heating step, and (b) is a front view after the heating step. [Figure 4] It is a front view schematically showing the artificial hair of the second embodiment of the present invention. [Figure 5] These are photographs of artificial hair representing examples and comparative examples of the present invention. (a) is a front view (top) and a cross-sectional view (bottom) of Example 1-1, (b) is a front view (top) and a cross-sectional view (bottom) of Example 1-2, (c) is a front view (top) and a cross-sectional view (bottom) of Example 1-3, (d) is a front view (top) and a cross-sectional view (bottom) of Example 1-4, and (e) is a front view (top) and a cross-sectional view (bottom) of Comparative Example 1-1. [Figure 6] These are photographs of artificial hair representing examples and comparative examples of the present invention. (a) is a front view (top) and a cross-sectional view (bottom) of Example 2-1, (b) is a front view (top) and a cross-sectional view (bottom) of Example 2-2, (c) is a front view (top) and a cross-sectional view (bottom) of Example 2-3, (d) is a front view (top) and a cross-sectional view (bottom) of Example 2-4, and (e) is a front view (top) and a cross-sectional view (bottom) of Comparative Example 2-1. [Modes for carrying out the invention]

[0029] Embodiments of the present invention will be described in detail below.

[0030] The artificial hair 1 of the first embodiment of the present invention is a hair ornament that is attached to the user's head, and is attached directly to the user's hair and / or to a braided portion of the user's hair when in use. Artificial hair 1 is what is known as bulk hair, and it can be used to create various styles by braiding it directly into the user's own hair or by attaching it to their own hair (cornrows) that are braided close to the scalp using a needle or similar tool. As shown in Figure 1, the artificial hair 1 is composed of one or more fiber cords 2, and each fiber cord 2 can be attached to hair or a braided section. The artificial hair 1 of this embodiment is composed of multiple fiber cords 2, and one end of each fiber cord 2 in the longitudinal direction (the root end) is connected via a connecting portion 13.

[0031] As shown in Figure 2(a), the fiber cord 2 is a rope-like structure formed by weaving together multiple fiber bundles 3, and extends in the longitudinal direction. As shown in Figure 2(b), fiber bundle 3 is a bundle of multiple fibers, each containing at least two types of fibers, including the first fiber 5 and the second fiber 6. The fiber bundle 3 in this embodiment is composed of two types of fibers: a first fiber 5 and a second fiber 6.

[0032] The first fiber 5 is a thread-like artificial hair fiber and is made of thermoplastic resin. The first fiber 5 is a high-shrinkage fiber with a higher thermal shrinkage rate than the second fiber 6, and is a shrink fiber that compresses the second fiber 6. The softening temperature of the first fiber 5 is preferably 50°C or higher and 100°C or lower. The thermal shrinkage rate in the elongation direction of the first fiber 5 when heated at 100°C for 60 minutes is preferably 10% to 80%, more preferably 15% to 70%, and even more preferably 40% to 60%. The first fiber 5 preferably has a thermal shrinkage rate of 10% or more, more preferably 15% to 70%, and even more preferably 40% to 60% when heated at the heating temperature T1 of the heating process described later for 10 minutes to 90 minutes. For example, polyvinyl chloride fibers can be used as the first fiber 5.

[0033] The second fiber 6 is a thread-like artificial hair fiber and is made of thermoplastic resin. When heated at the softening temperature of the first fiber 5, the second fiber 6 exhibits a relatively smaller thermal shrinkage rate than the first fiber 5, and can be considered a low-shrinkage fiber when the first fiber 5 is considered a high-shrinkage fiber. The second fiber 6 has a smaller thermal shrinkage rate than the first fiber 5 when heated at 100°C for 60 minutes, preferably with a thermal shrinkage rate of more than 0% and 5% or less, more preferably 4% or less, and even more preferably 3% or less. The second fiber 6 is preferably more than 0% and 5% or less, more preferably 4% or less, and even more preferably 3% or less, when heated at the heating temperature T1 of the heating process described later for 10 minutes or more and 90 minutes or less. The difference between the thermal shrinkage rate of the first fiber 5 and the thermal shrinkage rate of the second fiber 6 is preferably 15% or more, more preferably 25% or more, and even more preferably 40% or more when heated at the heating temperature T1 of the heating process described later for 10 minutes or more and 90 minutes or less.

[0034] The softening temperature of the second fiber 6 is a temperature that exceeds the softening temperature of the first fiber 5, and is preferably 50°C or higher than the softening temperature of the first fiber 5, more preferably 60°C or higher, even more preferably 70°C or higher, and particularly preferably 100°C or higher than the softening temperature of the first fiber 5.

[0035] The second fiber 6 preferably has a Young's modulus of 4.5 GPa or more and 10 GPa or less, in accordance with JIS L 1015:2010. For the second fiber 6, for example, polyester fibers, acrylic fibers, nylon fibers, etc., can be used. Examples of polyester fibers that can be used for the second fiber 6 include polyalkylene terephthalates such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate. For example, acrylic fibers can be used as the second fiber 6, and modacrylic fibers are preferred. In this context, "modacrylic fiber" refers to acrylic fiber in which the weight percentage of acrylonitrile is 35% or more but less than 85%. Examples of nylon fibers that can be used for the second fiber 6 include nylon 6, nylon 66, and copolymers of nylon 6 and nylon 66.

[0036] Furthermore, as shown in Figure 2(b), the fiber bundle 3 has a core portion 10 and a shell portion 11 in a cross-section perpendicular to the longitudinal direction. The core portion 10 is a part in which the first fiber 5 and the second fiber 6 are mixed, and is a roughly circular portion. The ratio of the cross-sectional area of ​​the first fiber 5 in the core portion 10 is greater than the ratio of the area of ​​the second fiber 6 in the core portion 10. In other words, the first fiber 5 occupies most of the core portion 10. The cross-sectional area of ​​the first fiber 5 in the core portion 10 is preferably 80% or more of the total cross-sectional area of ​​the core portion 10, more preferably 90% or more, and even more preferably 95% or more. The area of ​​the second fiber 6 in the core portion 10 is preferably 20% or less of the total area of ​​the core portion 10, more preferably 10% or less, and preferably 5% or less.

[0037] The shell portion 11 is formed to surround the core portion 10, as shown in Figure 2(b), and is composed solely of the second fiber 6. The thinnest thickness of the shell portion 11 (the distance from the outer edge of the core portion 10 to the outer edge of the shell portion 11) is preferably 0.1 mm or more, and more preferably 5 mm or more, from the viewpoint of adjusting the tactile feel of the shell portion 11 by the type of second fiber 6. It is preferable that the surface density of the shell portion 11 is lower than that of the core portion 10. In this context, "surface density" refers to the mass per unit area. It is preferable that the area porosity of the shell portion 11 is greater than that of the core portion 10. That is, as shown in Figure 2(b), in a cross section perpendicular to the longitudinal direction, the total area of ​​the voids 17 in the shell portion 11 is greater than the total area of ​​the voids 16 in the core portion 10. In this context, "area porosity" refers to the ratio of gaps (voids) per unit area.

[0038] In the fiber bundle 3, it is preferable that the area of ​​the shell portion 11 is greater than or equal to the area of ​​the core portion 10, and more preferably that the area of ​​the shell portion 11 is greater than the area of ​​the core portion 10. In the fiber bundle 3, it is preferable that the area ratio of the shell portion 11 to the core portion 10 is greater than the ratio of the mass of the second fiber 6 to the mass of the first fiber 5. This allows the fiber cord 2 to have a soft, fluffy texture.

[0039] In the fiber bundle 3, the second fiber 6 passes from inside the core portion 10 through the gap between adjacent first fibers 5, 5 to reach the shell portion 11. In other words, in the core portion 10, the first fiber 5 and the second fiber 6 are intertwined with each other.

[0040] The connecting portion 13 is a part that brings together the base ends of each fiber cord 2 and is composed of known connecting means such as thread, string, adhesive tape, or adhesive.

[0041] Next, the method for producing the artificial hair 1 of this embodiment will be described.

[0042] The artificial hair 1 of this embodiment mainly involves the following steps in this order: fiber cord formation, nonwoven fabric attachment, heating, and heat dissipation.

[0043] In other words, in the method for manufacturing artificial hair 1, first, the first fiber 5 and the second fiber 6 are bundled together to form multiple fiber bundles 3, and then the multiple fiber bundles 3 are braided together to form a fiber cord 2 (fiber cord formation step). Specifically, the first fiber 5 and the second fiber 6 are cut to any size and weighed, and the first fiber 5 and second fiber 6 cut to a predetermined mass are bundled together to form two fiber bundles 3. The bases of the two fiber bundles 3 are fixed to a fixing member, and the two bundles are braided together from the base side (one end side).

[0044] The length of the fibers 5 and 6 cut at this time can be appropriately changed depending on the length of the artificial hair 1 being manufactured, but it is preferably between 20 inches and 50 inches. The mass ratio of the first fiber 5 to the fiber bundle 3 is preferably 0.2 to 0.8, more preferably 0.3 to 0.7, and even more preferably 0.5 or less, from the viewpoint of sufficiently compressing the second fiber 6 by thermal shrinkage. That is, the amount of the first fiber 5 is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and even more preferably 50 parts by mass, based on 100 parts by mass of the total of the first fiber 5 and the second fiber 6. The mass ratio of the second fiber 6 to the fiber bundle 3 is a value such that the sum of the mass ratio of the second fiber 6 and the mass ratio of the first fiber 5 is 1. From the viewpoint of sufficiently covering the periphery of the first fiber 5, it is preferably 0.2 to 0.8, more preferably 0.3 to 0.7, and even more preferably 0.5 or more. That is, the amount of the second fiber 6 is preferably 20 to 80 parts by mass, more preferably 30 to 70 parts by mass, and even more preferably 50 parts by mass, relative to 100 parts by mass of the total of the first fiber 5 and the second fiber 6. Furthermore, it is preferable that the mass ratio of the second fiber 6 to the fiber bundle 3 is equal to or greater than the mass ratio of the first fiber 5 to the fiber bundle 3.

[0045] Next, as shown in Figure 3(a), a nonwoven fabric 12 is wrapped around a portion of the outer circumference of the fiber cord 2 formed in the fiber cord formation process (nonwoven fabric attachment process).

[0046] In this case, it is preferable to wrap the nonwoven fabric 12 around the fiber cord 2 from the tip end (the end of the fiber cord 2) to a range of 1 / 10 to 1 / 2 of the total length of the fiber cord 2, and more preferably to wrap it around a range of 1 / 3 or less.

[0047] Next, in the nonwoven fabric attachment process, the fiber cord 2 on which the nonwoven fabric 12 is wound is introduced into a heating device such as an oven and heated under the conditions of heating temperature T1 and heating time t1 (heating process).

[0048] In this case, as shown in Figures 3(a) to 3(b), the portion of the fiber cord 2 covered by the nonwoven fabric 12 is pressed down by the nonwoven fabric 12 and does not bulge easily, while the exposed portion 15 that is exposed from the nonwoven fabric 12 bulges mainly. In other words, the fiber cord 2 bulges significantly in parts along its length. The heating temperature T1 at this time is preferably a temperature above the softening temperature of the first fiber 5 and below the softening temperature of the second fiber 6. As a result, the softening temperatures of the first fiber 5 and the second fiber 6 are different, and the temperature of the second fiber 6 does not reach its softening temperature during the heating process. Therefore, the first fiber 5 mainly shrinks due to the heat, and the second fiber 6 is tightened around the first fiber 5 and tends to bulge outwards from the first fiber 5.

[0049] The combination of heating temperature T1 and heating time t1 is preferably such that the thermal shrinkage rate of the first fiber 5 is 5% or more, more preferably 15% or more, and even more preferably 30% or more. Furthermore, the combination of heating temperature T1 and heating time t1 is such that the thermal shrinkage rate of the second fiber 6 is smaller than that of the first fiber 5. The combination of heating temperature T1 and heating time t1 is preferably such that the heat shrinkage rate of the second fiber 6 is less than 5%, more preferably 2% or less, and even more preferably 1% or less. The combination of heating temperature T1 and heating time t1 is preferably such that the difference between the thermal shrinkage rate of the second fiber 6 and the thermal shrinkage rate of the first fiber 5 is 15% or more, and more preferably such that the difference is 20% or more. By setting the range as described above, the thermal shrinkage rates between the first fiber 5 and the second fiber 6 will differ. As the first fiber 5 shrinks, the second fiber 6 will be tightened against the first fiber 5 and tend to bulge outwards.

[0050] The heating temperature T1 is preferably 90°C to 140°C when, for example, a polyvinyl chloride fiber is used as the first fiber 5 and a polyester fiber is used as the second fiber 6. The heating time t1 can be appropriately changed according to the heating temperature T1 and the target quality, but from the viewpoint of penetrating the heat to the inside, it is preferably 15 minutes to 2 hours, and more preferably 30 minutes to 1 hour. Preferably, the total length of the fiber cord 2 after the heating process is 0.2 times or more and 0.7 times or less than the total length of the fiber cord 2 before the heating process.

[0051] Next, the fiber cords 2 that have been heated in the heating device in the heating process are removed from the heating device and cooled to room temperature (heat dissipation process).

[0052] In this case, the cooling method for the fiber bundle 3 may be natural heat dissipation, or it may be cooled by applying cold air at a certain speed, for example.

[0053] Subsequently, if necessary, multiple fiber cords 2 are connected by the connecting part 13 to complete the artificial hair 1. Specifically, multiple fiber cords 2 are tied together or bonded together within a range of 1 / 4 or less of the total length of the fiber cord 2 from one end of the fiber cord 2. Alternatively, the tip portion of the fiber cord 2 may be cut if necessary, leaving only the exposed portion 15 that is exposed from the nonwoven fabric 12 during the heating process.

[0054] According to the manufacturing method of the artificial hair 1 of the first embodiment, the first fiber 5 and the second fiber 6 are randomly bundled together, and the first fiber 5, which has a high thermal shrinkage rate, shrinks when heated. As the first fiber 5 shrinks, the second fiber 6 is squeezed, and the middle part of the second fiber 6 protrudes from the gaps of the first fiber 5, causing it to bulge outwards in a fluffy manner. As a result, it has an irregular, fluffy, and voluminous shape. Furthermore, according to the manufacturing method of the artificial hair 1 of the first embodiment, the apparent Young's modulus of the second fiber 6 is 5 GPa or higher, which is relatively large. Therefore, even if the second fiber 6 is compressed by the first fiber 5 and elastically deformed inward, the second fiber 6 can recover and expand outward from the first fiber 5.

[0055] In the first embodiment of artificial hair 1, the cross-section of the fiber bundle 3 comprises a core portion 10 and a shell portion 11, and the surface density of the shell portion 11 is lower than that of the core portion 10. Therefore, there are more voids 17 in the shell portion 11 compared to the voids 16 in the core portion 10, resulting in a fluffy, voluminous shape.

[0056] In the first embodiment of the artificial hair 1, a portion of the second fiber 6 constituting the fiber bundle 3 passes from inside the core portion 10 through the gap between adjacent first fibers 5, 5 to reach the shell portion 11, as shown in Figure 2(b). Therefore, the second fiber 6 is easily constricted by the adjacent first fibers 5, 5 and rises outwards, making it difficult for the second fiber 6 to come out of the core portion 10.

[0057] According to the first embodiment of the artificial hair 1, since the shell portion 11 is composed only of the second fiber 6, the color and texture of the artificial hair 1 can be adjusted by the color and texture of the second fiber 6.

[0058] Next, the artificial hair 101 of the second embodiment of the present invention will be described. Note that the same components and methods as those of the artificial hair 1 of the first embodiment are denoted by the same reference numerals and their descriptions are omitted.

[0059] The fiber cords 102 constituting the artificial hair 101 in the second embodiment of the present invention constitute dreadlocks. The fiber cord 102 is composed of fiber bundles 3, similar to the fiber cord 2 in the first embodiment, but the shape of the fiber bundles 3 differs from that of the fiber cord 2. Specifically, as shown in Figure 4, the fiber cord 102 is formed by winding a single fiber bundle 3 in a spiral shape.

[0060] Next, a method for producing the artificial hair 101 according to the second embodiment will be described.

[0061] The artificial hair 101 of the second embodiment is produced in the same order as the first embodiment, with the fiber cord formation step, heating step, and heat dissipation step being carried out in that order, except that the fiber cord formation step differs from that of the first embodiment. The fiber cord formation process of the second embodiment includes a winding process, a preheating process, and a removal process. Specifically, first, the first fiber 5 and the second fiber 6 are bundled together to form a fiber bundle 3, and the formed fiber bundle 3 is then wrapped around the outer circumference of a rod-shaped object such as a pipe (wrapping process).

[0062] At this time, the tips of the fiber bundle 3 are fixed, and the fiber bundle 3 is wrapped spirally around the rod-shaped body from one direction without twisting. That is, each fiber 5 and 6 extends in roughly the same direction. The outer shape of the rod-shaped body used in this case is not particularly limited; for example, circular, polygonal, elliptical, or oval shapes can be used. The minimum diameter of the inclusion circle of the rod-shaped body used in this process can be appropriately changed to match the target style shape, but it is preferably between 0.06 inches and 0.4 inches.

[0063] Next, in the winding process, the rod-shaped body with the fiber bundle 3 wound around it is introduced into a heating device and heated under the conditions of preheating temperature T2 and preheating time t2 (preheating process).

[0064] In this case, the combination of preheating temperature T2 and preheating time t2 is not particularly limited as long as it is a combination that allows the shape to be maintained when the fiber bundle 3 is removed from the rod-shaped body in the removal process. The preheating temperature T2 is preferably a temperature that is above the softening temperature of the first fiber 5 and below the heating temperature T1 set in the heating process. The preheating temperature T2 is preferably 80°C to 100°C when, for example, a polyvinyl chloride fiber is used as the first fiber 5 and a polyester fiber is used as the second fiber 6. The preheating time t2 is preferably 5 minutes or more and 30 minutes or less.

[0065] Next, the rod-shaped body with the fiber bundle 3, which has been heated in the preheating step, is removed from the heating device, and the fiber bundle 3 is removed from the rod-shaped body to form the fiber cord 102 (removal step).

[0066] At this point, the fiber bundle 3 has been curled by the heating in the preheating process, and the fiber cord 102, which has the same shape as when it was attached to the rod-shaped body, is removed from the rod-shaped body.

[0067] Once the fiber cord formation process is complete, a heating process and a heat dissipation process are carried out, similar to the first embodiment, and if necessary, a plurality of fiber cords 102 are connected by the connecting part 13 to form artificial hair 101.

[0068] In the first embodiment described above, two fiber bundles 3 were braided together to form a fiber cord 2, but the present invention is not limited thereto. For example, three fiber bundles 3 may be braided together to form a fiber cord, or two fiber bundles 3 may be braided together to form multiple braided bodies, and these braided bodies may be braided together to form a fiber cord.

[0069] In the first embodiment described above, the fibers 5 and 6 were bundled randomly to form the fiber bundle 3, but the present invention is not limited thereto. The fibers 5 and 6 may also be bundled regularly to form the fiber bundle. For example, the second fibers 6 may be bundled on the inside, and the first fibers 5 may be bundled on the outside so as to surround the outside of the second fibers 6. In this way, the contraction of the first fibers 5 will constrict the second fibers 6, allowing the second fibers 6 to be regularly exposed to the outside.

[0070] In the first embodiment described above, a nonwoven fabric attachment step was performed in which a nonwoven fabric 12 was wrapped around a part of the outer circumference of the fiber cord 2, but the present invention is not limited thereto. The nonwoven fabric attachment step may be omitted. For example, the heating step may be performed after the fiber cord formation step.

[0071] In the second embodiment described above, the fiber bundle 3 was wound around the rod-shaped body without twisting during the winding process, but the present invention is not limited thereto. The fiber bundle 3 may be wound around the rod-shaped body while twisting during the winding process.

[0072] In the embodiment described above, the fiber bundle 3 was formed using two types of fibers, the first fiber 5 and the second fiber 6, but the present invention is not limited thereto. Three or more types of fibers, including the first fiber 5 and the second fiber 6, may be bundled together to form a fiber bundle.

[0073] In the embodiments described above, the components can be freely substituted or added between each embodiment, as long as they fall within the technical scope of the present invention. [Examples]

[0074] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0075] (Example 1-1) First, a polyvinyl chloride fiber with a high thermal shrinkage rate (Kaneka Corporation, product name: Advantage-B) (hereinafter also referred to as high-PVC fiber) was used as the first fiber, and a flame-retardant polyester fiber (Kaneka Corporation, product name: Futura) (hereinafter also referred to as PET fiber) was used as the second fiber. The first and second fibers were each cut to 20 inches, and a brush was placed on a table so that the mass ratio of the first to second fibers was 30:70. The bundled fibers were brushed on the brush, shifting the ends of the bristles, until the total length was 25 inches. Then, the brushed fibers were bundled together to form two fiber bundles, and the two fiber bundles were braided together to form a fiber cord. Next, nonwoven fabric was wrapped around the fiber cord from the tip end to one-third of its total length. The fiber cord wrapped in nonwoven fabric was then placed in an oven and heated at a temperature of 90°C for 60 minutes. After that, it was removed from the oven and left to cool to room temperature. The fiber cord formed in this manner was designated as Example 1-1.

[0076] (Examples 1-2) Example 1-2 was created using the same procedure as in Example 1-1, except that the heating temperature was 100°C and the heating time was 60 minutes.

[0077] (Examples 1-3) Example 1-3 was created using the same procedure as in Example 1-1, except that the heating temperature was 120°C and the heating time was 60 minutes.

[0078] (Examples 1-4) Example 1-4 was created using the same procedure as in Example 1-1, except that the heating temperature was 140°C and the heating time was 60 minutes.

[0079] (Comparative Example 1-1) Comparative Example 1-1 was prepared in the same manner as in Example 1-1, except that the heating temperature was 70°C and the heating time was 60 minutes.

[0080] (Examples 1-5) Example 1-5 was constructed in the same manner as in Example 1-2, except that modacrylic fiber (Kaneka Corporation, product name: AFRELLE) (hereinafter also referred to as MODA fiber) was used as the second fiber.

[0081] (Examples 1-6) Example 1-6 was constructed in the same manner as in Example 1-2, except that polyvinyl chloride fiber (Kaneka Corporation, product name: ADM) (hereinafter also referred to as low-PVC fiber) with a lower heat shrinkage rate compared to high-PVC fiber was used as the first fiber.

[0082] (Comparative Example 1-2) Comparative Example 1-2 was constructed in the same manner as in Example 1-2, except that a low-PVC fiber was used as the second fiber.

[0083] (Examples 1-7) In Example 1-2, the brush was placed on a table so that the mass ratio of the first fiber to the second fiber was 50:50. The bundled fibers were brushed on the brush, shifting the tips of the bristles, and brushed until the total length was 25 inches. Two fiber bundles were formed by bundling the fibers together, and the two fiber bundles were braided together to form a fiber cord. Except for these differences, the process was carried out similarly, and this was designated as Example 1-7.

[0084] (Examples 1-8) In Example 1-2, the brush was placed on a table so that the mass ratio of the first fiber to the second fiber was 70:30. The bundled fibers were brushed on the brush, shifting the tips of the bristles, and brushed until the total length was 25 inches. Two fiber bundles were formed by bundling the fibers together, and the two fiber bundles were braided together to form a fiber cord. The rest of the procedure was the same, and this was designated as Example 1-8.

[0085] (Softening temperature measurement) The softening temperature of the fibers was measured using a thermal analyzer (SSC5200H) and a thermomechanical analyzer (TMA / SS150C) manufactured by Seiko Instruments Inc. Ten single fibers, each 10 mm in length, were taken, and a load of 0.0054 mN (total fineness of the ten fibers) was applied. The shrinkage stress was measured in the range of 30 to 300°C at a heating rate of 5°C / min, and the temperature at which the fiber shrank by 5% was defined as the softening temperature.

[0086] (Measurement of Young's modulus) Using a Tensilon universal material testing machine (RTC-1210A) manufactured by A&D Co., Ltd., the Young's modulus was determined from the stress-strain curve under a tensile speed of 20 cm / min, and the average value of N=20 was taken as the Young's modulus of the sample.

[0087] (Cross-sectional observation) In Examples 1-1 to 1-4 and Comparative Example 1-1, the fiber cords were frozen with liquid nitrogen, cut perpendicular to their longitudinal direction, and the cross-sections were photographed with a camera. The areas of the core and shell portions were calculated from the images of the cross-sections.

[0088] (Width measurement) In Examples 1-1 to 1-8 and Comparative Examples 1-1 and 1-2, the width of the portion exposed from the nonwoven fabric during heating was measured at three points: 5 cm from the top edge, the center, and 5 cm from the bottom edge, and the average value was calculated.

[0089] Figure 5 shows the results of cross-sectional observations of Examples 1-1 to 1-4 and Comparative Example 1-1. Table 1 shows the measurement results for Examples 1-1 to 1-4 and Comparative Example 1-1. Table 2 shows the measurement results for Examples 1-2, 1-5, 1-6, and Comparative Example 1-2. Table 3 shows the measurement results for Examples 1-2, 1-7, and 1-8.

[0090] [Table 1]

[0091] [Table 2]

[0092] [Table 3]

[0093] Note that the thermal shrinkage rate is the inherent thermal shrinkage rate of each material, and represents the thermal shrinkage rate of the individual material when heated at the heating temperature for 60 minutes. Each width ratio in Table 1 is standardized based on Comparative Example 1-1, so that the width of Comparative Example 1-1 becomes 1. Each width ratio in Table 2 is standardized based on Comparative Example 1-2, so that the width of Comparative Example 1-2 becomes 1. The width ratios in Table 3 are based on Examples 1-8, and have been standardized so that the width of Example 1-8 is 1.

[0094] In Comparative Example 1-1, as shown in Figure 5(e), the first and second fibers were evenly mixed in a cross-section perpendicular to the longitudinal direction, and the ratio of first to second fibers was generally uniform. On the other hand, in Examples 1-1 to 1-4, as shown in Figures 5(a) to 5(d), the first fibers were locally concentrated in the cross-section, and the core portion consisting of first and second fibers and the shell portion consisting only of second fibers were clearly separated. Also, as shown in Figure 5, the overall length decreased as the heating temperature increased, and in Examples 1-1 to 1-4, the size of the core portion relative to the overall cross-section became smaller. Furthermore, in Examples 1-1 to 1-4, where a core and a shell were formed, it could be seen, as shown in Figure 5, that the total area of ​​voids in the shell portion in the cross-section was larger than the total area of ​​voids in the core portion.

[0095] As shown in Table 1, in Examples 1-1 to 1-4, where the heating temperature was above the softening temperature of the high-PVC fiber, the width was increased by more than 90% compared to Comparative Example 1-1, where the heating temperature was below the softening temperature of the high-PVC fiber, and the width ratio decreased as the heating temperature increased.

[0096] As shown in Table 1, in Examples 1-1 to 1-4, the ratio of the core area to the total area was smaller than the ratio of the mass of the first fiber to the total mass (30%), and the ratio of the shell area to the total area was larger than the ratio of the mass of the second fiber to the total mass (70%). In other words, in Examples 1-1 to 1-4, where the heating temperature exceeded the softening temperature of the high-PVC fiber, the ratio of the shell area to the core area was larger than the ratio of the mass of the second fiber to the mass of the first fiber (70 / 30).

[0097] As shown in Table 2, compared to Comparative Example 1-2, where the heating temperature was set to a temperature above the softening temperature of the first and second fibers, Examples 1-2, 1-5, and 1-6, where the heating temperature was set to a temperature higher than the softening temperature of the first fiber but lower than the softening temperature of the second fiber, showed an improvement of 30% or more in width ratio. Compared to Comparative Example 1-2, in which the thermal shrinkage rate of the first and second fibers at the heating temperature was 10% or more, Examples 1-2, 1-5, and 1-6, in which the thermal shrinkage rate of the first fiber at the heating temperature was 10% or more and the thermal shrinkage rate of the second fiber at the heating temperature was 5% or less, showed an improvement of 30% or more in width ratio, and in particular, Examples 1-2 and 1-6, in which the thermal shrinkage rate of the second fiber at the heating temperature was less than 1%, showed an improvement of 50% or more.

[0098] Comparing Examples 1-2 and 1-6, which have different Young's moduli of the first fiber, Example 1-2, with its higher Young's modulus, had a larger width ratio compared to Example 1-6. When comparing Examples 1-2, 1-5, and Comparative Example 1-2, which have different Young's moduli of the second fiber, the width ratio increased as the Young's moduli increased. In Examples 1-2, 1-5, and 1-6, where the cross-section was separated into a core portion and a shell portion, the width ratio was 30% or more higher than in Comparative Example 1-2, where the cross-section was not separated into a core portion and a shell portion. In particular, in Example 1-2, where the ratio of the shell area to the core area was greater than the ratio of the mass of the second fiber to the mass of the first fiber, the width ratio was improved by 80% compared to Comparative Example 1-2.

[0099] As shown in Table 3, in Examples 1-2, 1-7, and 1-8, which have different mass ratios, the width ratio increased as the mass ratio of the second fiber increased. Furthermore, in Examples 1-2, 1-7, and 1-8, the ratio of the core area to the total area was smaller than the ratio of the mass of the first fiber to the total mass, and the ratio of the shell area to the total area was larger than the ratio of the mass of the second fiber to the total mass. In other words, in Examples 1-2, 1-7, and 1-8, the ratio of the shell area to the core area was larger than the ratio of the mass of the second fiber to the mass of the first fiber.

[0100] From the above, it is suggested that by heating at a heating temperature above the softening temperature of the first fiber, using a fiber with a thermal shrinkage rate of 10% or more at the heating temperature as the first fiber, and using a fiber with a thermal shrinkage rate of 5% or less at the heating temperature as the second fiber, the first fiber shrinks during heating, pushing the second fiber outward, increasing the surface area of ​​the shell, and improving the width volume.

[0101] (Example 2-1) First, high-PVC fiber was used as the primary fiber, and PET fiber was used as the secondary fiber. The first and second fibers were each cut to 20 inches, and a brush was placed on a desk. The bundled fibers were then brushed on the brush, shifting the ends of the bristles, until the total length was 25 inches, forming a single fiber bundle. Next, the fiber bundles were secured to a 0.2-inch diameter pipe with rubber tips, and the fibers were wound spirally around the pipe without twisting to form a fiber cord. Next, the fiber ducts fixed to the pipes were placed in an oven and preheated at a preheating temperature of 90°C for 20 minutes. After preheating was complete, the fiber cords fixed to the pipes were removed from the oven, the fiber cords were detached from the pipes, and only the fiber cords were placed back into the oven for main heating at a temperature of 90°C for 20 minutes. Once the heating was complete, the fiber cords were removed from the oven and allowed to cool naturally until the fiber bundles reached room temperature. The fiber bundle formed in this manner was designated as Example 2-1.

[0102] (Example 2-2) Example 2-2 was constructed in the same manner as in Example 2-1, except that the heating temperature was set to 100°C.

[0103] (Examples 2-3) Example 2-3 was constructed in the same manner as in Example 2-1, except that the heating temperature was set to 120°C.

[0104] (Examples 2-4) Example 2-4 was constructed in the same manner as in Example 2-1, except that the heating temperature was set to 140°C.

[0105] (Comparative Example 2-1) Comparative Example 2-1 was prepared in the same manner as in Example 2-1, except that the heating temperature was set to 80°C.

[0106] (Examples 2-5) Example 2-5 was created using the same procedure as in Example 2-2, except that MODA fiber was used as the second fiber and the preheating temperature was set to 80°C.

[0107] (Examples 2-6) Example 2-6 was constructed in the same manner as in Example 2-2, except that a low-PVC fiber was used as the first fiber.

[0108] (Comparative Example 2-2) Comparative Example 2-2 was constructed in the same manner as in Example 2-2, except that a low-PVC fiber was used as the second fiber and the preheating temperature was set to 75°C.

[0109] Figure 6 shows the results of cross-sectional observations of Examples 2-1 to 2-4 and Comparative Example 2-1, Table 4 shows the measurement results for Examples 2-1 to 2-4 and Comparative Example 2-1, and Table 5 shows the measurement results for Examples 2-2, 2-5, 2-6, and Comparative Example 2-2.

[0110] [Table 4]

[0111] [Table 5]

[0112] Note that the thermal shrinkage rate is the inherent thermal shrinkage rate of each material, and represents the thermal shrinkage rate of the individual material when heated at the heating temperature for 60 minutes. Each width ratio in Table 4 is standardized so that the width of Comparative Example 2-1 is 1, and each width ratio in Table 5 is standardized so that the width of Comparative Example 2-2 is 1.

[0113] In Comparative Example 2-1, as shown in Figure 6(e), the first and second fibers were evenly mixed in a cross-section perpendicular to the longitudinal direction, and the ratio of first to second fibers was generally uniform. On the other hand, in Examples 2-1 to 2-4, as shown in Figures 6(a) to 6(d), the first fibers were locally concentrated in the cross-section, and the core portion consisting of first and second fibers and the shell portion consisting only of second fibers were clearly separated. Also, as shown in Figure 6, the overall length decreased as the heating temperature increased, and in Examples 2-1 to 2-4, the size of the core portion relative to the overall cross-section became smaller. Furthermore, in Examples 2-1 to 2-4, where a core and a shell were formed, it could be seen, as shown in Figure 6, that the total area of ​​voids in the shell portion in the cross-section was larger than the total area of ​​voids in the core portion.

[0114] As shown in Table 4, compared to Comparative Example 2-1, where the heating temperature was below the softening temperature of polyvinyl chloride, the width increased by more than 10% in Examples 2-1 to 2-4, where the heating temperature was above the softening temperature of polyvinyl chloride, and in particular, the width increased by more than 50% in Examples 2-3 and 2-4. In Examples 2-1 and 2-2, the ratio of the core area to the total area was greater than the ratio of the mass of the first fiber to the total mass (30%), and the ratio of the shell area to the total area was less than the ratio of the mass of the second fiber to the total mass (70%). In other words, in Examples 2-1 and 2-2, the ratio of the shell area to the core area was less than the ratio of the mass of the second fiber to the mass of the first fiber (70 / 30). On the other hand, in Examples 2-3 and 2-4, where the width was significantly increased, the ratio of the core area to the total area was smaller than the mass ratio of the first fiber to the total mass (30%), and the ratio of the shell area to the total area (70%) was larger than the mass ratio of the second fiber to the total mass. In other words, in Examples 2-3 and 2-4, the ratio of the shell area to the core area was greater than the ratio of the second fiber mass to the first fiber mass (70 / 30).

[0115] As shown in Table 5, compared to Comparative Example 2-2, where the heating temperature was set to a temperature above the softening temperature of the first and second fibers, Examples 2-2, 2-5, and 2-6, where the heating temperature was set higher than the softening temperature of the first fiber but lower than the softening temperature of the second fiber, showed an improvement of 5% or more in width ratio. Furthermore, compared to Comparative Example 2-2, in which the thermal shrinkage rate of the first and second fibers at the heating temperature was 10% or more, Examples 2-2, 2-5, and 2-6, in which the thermal shrinkage rate of the first fiber at the heating temperature was 10% or more and the thermal shrinkage rate of the second fiber at the heating temperature was 5% or less, showed an improvement of 5% or more in width ratio, and Examples 2-2 and 2-5, in which the difference in thermal shrinkage rate between the first and second fibers was 40% or more, showed an improvement of 40% or more.

[0116] Comparing Example 2-2 and Example 2-6, which have different Young's moduli of the first fiber, Example 2-2, with its higher Young's modulus, had a larger width ratio compared to Example 2-6. Furthermore, when comparing Examples 2-2, 2-5, and Comparative Example 2-2, which have different Young's moduli of the second fiber, the width ratio increased as the Young's moduli increased.

[0117] As described above, the results from Examples 2-1 to 2-6, which underwent both the preheating and heating processes, suggest that by heating at a temperature above the softening temperature of the first fiber, using a fiber with a thermal shrinkage rate of 10% or more at the heating temperature as the first fiber, and using a fiber with a thermal shrinkage rate of 5% or less at the heating temperature as the second fiber, the first fiber shrinks during heating, pushing the second fiber outward, increasing the surface area of ​​the shell and improving the width volume.

[0118] From the above results, it was found that by heating the first fiber at a heating temperature above its softening temperature, using a fiber as the first fiber with a thermal shrinkage rate of 10% or more when heated at the heating temperature for 60 minutes, and using a fiber as the second fiber with a thermal shrinkage rate of 5% or less when heated at the heating temperature for 60 minutes, it is possible to form a fiber cord with a cross-section having a core and shell portion with different porosities, resulting in a more irregular, fluffy, and voluminous shape compared to conventional methods. [Explanation of Symbols]

[0119] 1,101 Artificial hair 2,102 fiber cords 3 Fiber bundles 5. First Fiber 6. Second Fiber 10 Core section 11 Shell section 12 Nonwoven fabric 16,17 void

Claims

1. Having a fiber cord in which one or more fiber bundles are woven together or wound in a spiral, The aforementioned fiber bundle is made up of multiple fibers, including a first fiber and a second fiber. The cross-section perpendicular to the longitudinal direction of the fiber bundle has a core portion and a shell portion surrounding the core portion. The core portion contains a mixture of the first and second fibers. The shell portion is composed of the second fiber, Artificial hair in which the total area of ​​voids in the shell portion in the cross-section is greater than the total area of ​​voids in the core portion in the cross-section.

2. The artificial hair according to claim 1, wherein in the cross-section, the ratio of the area of ​​the shell portion to the area of ​​the core portion of the fiber bundle is greater than the ratio of the mass of the second fiber to the mass of the first fiber.

3. The artificial hair according to claim 1 or 2, wherein the second fiber extends from inside the core portion through the gaps between adjacent first fibers to the shell portion.

4. The artificial hair according to any one of claims 1 to 3, wherein the area of ​​the shell portion in the cross-section is larger than the area of ​​the core portion.

5. The artificial hair according to any one of claims 1 to 4, wherein the thinnest thickness of the shell portion in the cross-section is 0.1 mm or more.

6. The artificial hair according to any one of claims 1 to 5, wherein the second fiber is in an amount of 20 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the total of the first fiber and the second fiber.

7. The artificial hair according to claim 6, wherein the second fiber is 50 parts by mass or more with respect to 100 parts by mass of the total of the first fiber and the second fiber.

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