WO2023105889A1

WO2023105889A1 - Fiber bundle for artificial hair, and headwear product comprising same

Info

Publication number: WO2023105889A1
Application number: PCT/JP2022/035476
Authority: WO
Inventors: 井野友梨奈
Original assignee: 株式会社カネカ
Priority date: 2021-12-10
Filing date: 2022-09-22
Publication date: 2023-06-15

Abstract

One or more embodiments of the present invention relate to a fiber bundle for artificial hair, the fiber bundle comprising two or more kinds of core-sheath composite fibers having different core/sheath ratios, wherein: each core-sheath composite fiber comprises a core part and a sheath part; and the core/sheath ratio is expressed by the area ratio of the core part to the sheath part. With respect to each core-sheath composite fiber, the core part is configured from a polyester resin composition that contains a polyester resin; and the sheath part is configured from a polyamide resin composition that contains a polyamide resin. The standard deviation of the ratio of the core part cross-sectional area to the fiber cross-sectional area of the core-sheath composite fibers that constitute the fiber bundle for artificial hair is 0.15 or more. Consequently, the present invention provides: a fiber bundle for artificial hair, the fiber bundle containing core-sheath composite fibers and having texture and appearance similar to those of human hair as well as good curl setting properties and durability in use; and a headwear product which comprises this fiber bundle for artificial hair.

Description

Fiber bundles for artificial hair and headdress products containing the same

The present invention relates to an artificial hair fiber bundle composed of core-sheath composite fibers and a headdress product containing the same.

In addition to human hair, artificial hair is widely used in head decoration products such as wigs, hair wigs, hair extensions, hair bands, and doll hair. As materials for artificial hair, acrylic fibers, vinyl chloride fibers, vinylidene chloride fibers, polyester fibers, polyamide fibers, polyolefin fibers, and the like are used. Among them, polyamide fibers are known to have excellent tactile sensation and durability in use, and to have a soft texture, and polyester fibers are known to have good curl setting properties and curl retention properties. In order to obtain artificial hair having both properties of polyamide fibers and polyester fibers, polyamide and polyester are combined. For example, Patent Literatures 1 and 2 propose core-sheath conjugate fibers having polyester as a core component and polyamide as a sheath component as fibers for artificial hair.

JP-A-3-185103 International Publication No. 2017/187843

However, in the case of the core-sheath conjugate fibers described in Patent Documents 1 and 2, depending on the core-sheath ratio, the curl set property and durability in use are inferior, and the natural appearance and feel of human hair cannot be obtained. There was a problem.

In order to solve the above-mentioned problems, the present invention includes a fiber bundle for artificial hair that contains a core-sheath composite fiber, has a texture and appearance similar to human hair, and has excellent curl setting properties and durability in use, and the fiber bundle containing the same. The Company provides headdress products.

One or more embodiments of the present invention provide a fiber bundle for artificial hair containing core-sheath composite fibers having two or more different core-sheath ratios, wherein each core-sheath composite fiber includes a core portion and a sheath portion. The sheath ratio is expressed as the area ratio of the core to the sheath. Artificial hair comprising a polyamide-based resin composition containing a resin, wherein the standard deviation of the ratio of the core cross-sectional area to the fiber cross-sectional area of the core-sheath composite fibers constituting the fiber bundle for artificial hair is 0.15 or more. for fiber bundles.

One or more embodiments of the present invention relate to headdress products containing the artificial hair fiber bundles.

INDUSTRIAL APPLICABILITY According to the present invention, there is provided a fiber bundle for artificial hair which contains core-sheath composite fibers, has a texture and appearance similar to those of human hair, and has excellent curl setting properties and durability in use, and a head ornament product containing the same. be able to.

1 is a schematic diagram showing a fiber cross section of one example of a core-sheath composite fiber. FIG. 1 is a micrograph (500×) of a cross section of the fiber bundle of Example 1. FIG. 3 is a micrograph (500 times) of a cross section of the fiber bundle of Example 2. FIG. 4 is a micrograph (500 times) of a cross section of the fiber bundle of Comparative Example 1. FIG. It is a schematic explanatory drawing of a bulk-height measuring machine. It is a schematic explanatory drawing of a bulk-height measuring machine. It is a schematic explanatory drawing of a bulk-height measuring machine.

The present inventors have found that, in some cases, an artificial hair fiber bundle using one type of core-sheath composite fiber, that is, an artificial hair fiber bundle composed only of fibers having a single core-sheath ratio, may cause curl set. We found that the properties and durability of use were inferior, and that the natural appearance and touch feeling of human hair could not be obtained. As a result, in a fiber bundle for artificial hair containing a core-sheath composite fiber having a core-sheath structure, a core portion made of a polyester-based resin composition, and a sheath portion made of a polyamide-based resin composition, two or more types of fiber bundles were found. In addition to using core-sheath composite fibers having different core-sheath ratios together, the standard deviation of the ratio of the core cross-sectional area to the fiber cross-sectional area of the core-sheath composite fiber (hereinafter also simply referred to as the core cross-sectional area ratio) is determined to a predetermined value. It was found that by setting the value to 0.5, a tactile feel and appearance similar to those of human hair are exhibited, and curl set property and durability in use are improved.
The above problem cannot be solved only by using two or more types of core-sheath composite fibers having different core-sheath ratios in combination. It is important to set the deviation to a predetermined value.
In a fiber bundle for artificial hair containing core-sheath composite fibers having two or more different core-sheath ratios, the standard deviation of the cross-sectional area ratio of the core of the core-sheath composite fibers is set to 0.15 or more, so that the core and the sheath are It is possible to effectively utilize the characteristics of the part.

<Fiber bundle for artificial hair>
A fiber bundle for artificial hair (hereinafter also simply referred to as "fiber bundle") includes core-sheath composite fibers having two or more different core-sheath ratios. Each core-sheath composite fiber includes a core portion and a sheath portion, and the core-sheath ratio is expressed by the area ratio of the core portion to the sheath portion. This includes core-sheath composite fibers having different sheath area ratios.

In the fiber bundle, the standard deviation of the core cross-sectional area ratio of the core-sheath composite fiber can be calculated by observing the cross section of the fiber bundle with a laser microscope and analyzing it using an image analyzer. Specifically, the cross section of the fiber bundle is observed with a laser microscope, and an area containing about 100 fibers, for example, 80 to 120 fibers is selected as a measurement area, and an image analysis device (manufactured by Mitani Shoji Co., Ltd., image analysis Using the software "Win ROOF"), the area of the fiber cross section, the core section and the sheath section of each core-sheath composite fiber is calculated, and using the following formula (1), all the core-sheath in the measurement area It is possible to calculate the standard deviation of the core cross-sectional area ratio in the fiber bundle containing the conjugate fiber.

In the fiber bundle, the standard deviation of the core cross-sectional area ratio is 0.15 or more. As a result, the fiber bundle develops a feel and appearance similar to those of human hair, and has good curl setting properties and durability in use. The standard deviation of the cross-sectional area ratio of the core portion of the fiber bundle is preferably 0.16 or more, more preferably 0.17 or more, from the viewpoint of approximating the feel and appearance of human hair. Although the upper limit of the standard deviation of the core cross-sectional area ratio is not particularly limited, it may be 0.20 or less, for example, from the viewpoint of expressing good touch, appearance, curl set property, and durability in use.

In the fiber bundle, the number of types of core-sheath composite fibers having different core-sheath ratios may be two or more, and is not particularly limited. For example, 2 to 6 types may be used, or 2 types, 3 types, 4 types, 5 types, or 6 types may be used. The core-sheath ratio of each core-sheath composite fiber is preferably in the range of 3:7 to 8:2 (core:sheath) in area ratio. By using core-sheath composite fibers having a core-sheath ratio within this range and having two or more different core-sheath ratios, it is easy to obtain the same tactile feel and texture as human hair.

The mixing ratio of the core-sheath composite fibers having different core-sheath ratios in the fiber bundle is not particularly limited, and can be appropriately set so that the standard deviation of the core cross-sectional area ratio satisfies the above-described range. From the viewpoint of making the appearance more similar to human hair, the content of the core-sheath composite fiber having the same core-sheath ratio is preferably 5% by weight or more and 90% by weight or less, and 10% by weight, based on the total weight of the fiber bundle. It is more preferably 80 wt% or less, more preferably 10 wt% or more and 70 wt% or less, even more preferably 10 wt% or more and 60 wt% or less, 10 wt% or more and 50 wt% or less, and even more preferably 10% by weight or more and 40% by weight or less.

The core-sheath composite fiber preferably has a core portion inside the sheath portion in the cross section of the fiber, and may have a concentric structure in which the center position of the core portion coincides with the center position of the fiber. An eccentric structure that does not coincide with the center position and is eccentric may be used. From the viewpoint of spinning stability and curl setting properties, it is preferable that the core has a concentric structure in which the central position of the core coincides with the central position of the fiber. In the fiber cross section of the core-sheath composite fiber, in order to prevent separation of the core and the sheath, it is preferable that the core is completely covered with the sheath without being exposed on the surface of the fiber.

The cross-sectional shape of the core-sheath composite fiber may be circular or irregular. Variant shapes include oval and flattened shapes such as flat multilobed. The flattened polylobes include, for example, flattened bilobed, flattened tetralobed, and the like. Also, the cross-sectional shape of the core may be circular or irregular. Variant shapes include oval and flattened shapes such as flat multilobed. The flattened polylobes include, for example, flattened bilobed, flattened tetralobed, and the like. From the viewpoint of tactile sensation, the cross-sectional shape of the core-sheath composite fiber and the core is preferably flat. The cross-sectional shape of the core-sheath composite fiber and the cross-sectional shape of the core may be the same or different.

A flat multi-leaf is a combination of two or more leaf shapes selected from the group consisting of circular and elliptical shapes through recesses. A flattened bilobate is a combination of two lobes selected from the group consisting of circular and elliptical lobes through a recess. The circular and/or oval shapes may partially overlap at the joint. Also, the circular or elliptical shape does not necessarily have to draw a continuous arc, and includes partially deformed substantially circular or substantially elliptical shapes as long as the corners are not sharp. Concerning the cross-sectional shape, unevenness of 2 μm or less generated on the outer periphery of the fiber and the core due to additives and the like shall not be taken into consideration. The cross-sectional shape of the fiber and core can be controlled by using a nozzle (hole) with a shape close to the desired cross-sectional shape.

FIG. 1 is a schematic diagram showing a fiber cross section of one example of the core-sheath composite fiber for artificial hair of the present invention. The core-sheath composite fiber 1 includes a sheath portion 10 and a core portion 20, and both the fiber 1 and the core portion 20 have a flat bilobal fiber cross section in which two oval shapes are joined via a recess. The ellipses partially overlap at the joints.

In a flat bilobal fiber cross section, the length of the long axis of the fiber cross section, which is the maximum length among straight lines connecting any two points on the outer periphery of the fiber cross section parallel to the line symmetry axis and the line symmetry axis L and the first short axis of the fiber cross section, which is a straight line connecting two points with the maximum length when connecting any two points on the outer periphery of the fiber cross section so that it is perpendicular to the long axis of the fiber cross section. Preferably, the length S1 satisfies the following formula (2).
L/S1=1.1 or more and 2.0 or less (2)

In a flat bilobate fiber cross section, the axis of symmetry and the straight line connecting any two points on the outer periphery of the core cross section parallel to the axis of symmetry, the straight line with the maximum length of the long axis of the core cross section A cross section of the core that is a straight line that connects two points having the maximum length when connecting arbitrary two points on the outer periphery of the cross section of the core so that the length Lc is perpendicular to the long axis of the cross section of the core. The length Sc1 of the first minor axis preferably satisfies the following formula (3).
Lc/Sc1=1.3 or more and 2.0 or less (3)

From the viewpoint that the core-sheath composite fiber is suitable for artificial hair, the single fiber fineness is preferably 10 dtex or more and 150 dtex or less, more preferably 30 dtex or more and 120 dtex or less, still more preferably 40 dtex or more and 100 dtex or less, and particularly preferably. is 50 dtex or more and 90 dtex or less.

The core-sheath composite fibers do not necessarily have to have the same fineness and cross-sectional shape even when the core-sheath ratio is the same, and fibers having different fineness and cross-sectional shape may be mixed.

The core is composed of a polyester resin composition containing a polyester resin, specifically a polyester resin composition containing a polyester resin as a main component. A polyester resin composition containing a polyester resin as a main component means that the polyester resin composition contains more than 50% by weight of the polyester resin when the total weight of the polyester resin composition is 100% by weight. It preferably contains 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 95% by weight or more.

As the polyester-based resin, it is preferable to use one or more selected from the group consisting of polyalkylene terephthalate and copolyester mainly composed of polyalkylene terephthalate. "Copolyester mainly composed of polyalkylene terephthalate" refers to a copolymer polyester containing 80 mol% or more of polyalkylene terephthalate.

The polyalkylene terephthalate is not particularly limited, but examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polycyclohexanedimethylene terephthalate.

The copolymer polyester mainly composed of polyalkylene terephthalate is not particularly limited, but for example, it is mainly composed of polyalkylene terephthalate such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, and other copolymer components. The copolyester containing, etc. are mentioned.

Other copolymerization components include, for example, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, trimellitic acid, pyromellitic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, and sebacic acid. , dodecanedioic acid and their derivatives; dicarboxylic acids and their derivatives including sulfonates such as 5-sodium sulfoisophthalic acid and dihydroxyethyl 5-sodium sulfoisophthalate; 1,2-propanediol , 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol, polyethylene glycol, trimethylolpropane, pentaerythritol and other polyalcohols; 4-hydroxybenzoic acid, ε-caprolactone, ethylene glycol ether of bisphenol A, and the like.

From the standpoints of stability and ease of operation, the copolymerized polyester is preferably produced by reacting polyalkylene terephthalate, which is the main component, with a small amount of other copolymerized components. As polyalkylene terephthalate, a polymer of terephthalic acid and/or its derivative (for example, methyl terephthalate) and alkylene glycol can be used. Copolyester is a mixture of terephthalic acid and/or its derivatives (e.g., methyl terephthalate) used in the polymerization of polyalkylene terephthalate, which is the main component, and alkylene glycol, and a small amount of other copolymerization components, monomers or oligomers. You may manufacture by polymerizing what contained the component.

The copolymerized polyester may be polycondensed with the above-mentioned other copolymerized components on the main chain and/or side chains of the main polyalkylene terephthalate, and the method of copolymerization is not particularly limited.

Specific examples of copolyesters mainly composed of polyalkylene terephthalate include, for example, mainly polyethylene terephthalate, ethylene glycol ether of bisphenol A, 1,4-cyclohexadimethanol, isophthalic acid and dihydroxyethyl 5-sodium sulfoisophthalate. Examples include polyesters obtained by copolymerizing one kind of compound selected from the group consisting of.

The polyalkylene terephthalate and the polyalkylene terephthalate-based copolyester may be used alone or in combination of two or more. Among them, polyethylene terephthalate; polypropylene terephthalate; polybutylene terephthalate; polyester mainly composed of polyethylene terephthalate and copolymerized with ethylene glycol ether of bisphenol A; A polyester mainly composed of terephthalate and copolymerized with isophthalic acid; and a polyester mainly composed of polyethylene terephthalate and copolymerized with dihydroxyethyl 5-sodiumsulfoisophthalate are preferably used alone or in combination of two or more.

The intrinsic viscosity (sometimes referred to as IV value) of the polyester resin is not particularly limited, but is preferably 0.3 dL/g or more and 1.2 dL/g or less, and 0.4 dL/g or more and 1.0 dL/g or more. g or less is more preferable. When the intrinsic viscosity is 0.3 dL/g or more, the mechanical strength of the obtained fiber does not decrease, and there is no danger of dripping during the combustion test. Further, when the intrinsic viscosity is 1.2 dL/g or less, the molecular weight does not increase too much, the melt viscosity does not increase too much, melt spinning is facilitated, and the fineness tends to be uniform.

The polyester-based resin composition may contain other resins in addition to the polyester-based resin. Examples of other resins include polyamide-based resins, vinyl chloride-based resins, modacrylic-based resins, polycarbonate-based resins, polyolefin-based resins, and polyphenylene sulfide-based resins. These may be used individually by 1 type, and may use 2 or more types together.

The sheath is composed of a polyamide-based resin composition containing a polyamide-based resin, that is, a polyamide-based resin composition containing a polyamide-based resin as a main component. A polyamide-based resin composition containing a polyamide-based resin as a main component means that the polyamide-based resin is contained in an amount of more than 50% by weight when the total weight of the polyamide-based resin composition is 100% by weight. Preferably, it contains 60% by weight or more, more preferably 70% by weight or more, more preferably 80% by weight or more, even more preferably 90% by weight or more, and even more preferably 95% by weight or more. preferable.

Polyamide resin is a nylon obtained by polymerizing one or more selected from the group consisting of lactams, aminocarboxylic acids, mixtures of dicarboxylic acids and diamines, mixtures of dicarboxylic acid derivatives and diamines, and salts of dicarboxylic acids and diamines. means resin.

Specific examples of lactams include, but are not limited to, 2-azetidinone, 2-pyrrolidinone, δ-valerolactam, ε-caprolactam, enantholactam, capryllactam, undecalactam, and laurolactam. . Among these, ε-caprolactam, undecalactam and laurolactam are preferred, and ε-caprolactam is particularly preferred. These lactams may be used singly or as a mixture of two or more.

Specific examples of aminocarboxylic acids are not particularly limited, but include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, 12 -aminododecanoic acid and the like. Among these, 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid are preferred, and 6-aminocaproic acid is particularly preferred. These aminocarboxylic acids may be used singly or as a mixture of two or more.

Specific examples of dicarboxylic acids used in mixtures of dicarboxylic acids and diamines, mixtures of dicarboxylic acid derivatives and diamines, or salts of dicarboxylic acids and diamines are not particularly limited, but include oxalic acid, malonic acid, succinic acid, glutaric acid, acids, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, tetradecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid, etc. alicyclic dicarboxylic acids, phthalic acid, isophthalic acid, terephthalic acid, and aromatic dicarboxylic acids such as naphthalene dicarboxylic acid. Among these, adipic acid, sebacic acid, dodecanedioic acid, terephthalic acid and isophthalic acid are preferred, and adipic acid, terephthalic acid and isophthalic acid are particularly preferred. These dicarboxylic acids may be used singly or as a mixture of two or more.

Specific examples of diamines used in mixtures of dicarboxylic acids and diamines, mixtures of dicarboxylic acid derivatives and diamines, or salts of dicarboxylic acids and diamines are not particularly limited. Diaminopentane, 1,6-diaminohexane, 2-methyl-1,5-diaminopentane (MDP), 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane , 1,11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminohepta Aliphatic diamines such as decane, 1,18-diaminooctadecane, 1,19-diaminononadecane, 1,20-diaminoeicosane, alicyclic diamines such as cyclohexanediamine, bis-(4-aminohexyl)methane, m -xylylenediamine, p-xylylenediamine and other aromatic diamines. Among these, aliphatic diamines are particularly preferred, and hexamethylenediamine is particularly preferred. These diamines may be used singly or as a mixture of two or more.

Polyamide resin (also referred to as nylon resin) is not particularly limited, but for example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 6-10, nylon 6-12, nylon 6T and / or 6I units It is preferable to use semi-aromatic nylons containing and copolymers of these nylon resins. In particular, nylon 6, nylon 66, and copolymers of nylon 6 and nylon 66 are more preferred.

Polyamide-based resins can be produced, for example, by a polyamide-based resin polymerization method in which a polyamide-based resin raw material is heated in the presence or absence of a catalyst. Stirring may or may not be used during the polymerization, but stirring is preferred in order to obtain a homogeneous product. The polymerization temperature can be arbitrarily set according to the degree of polymerization of the target polymer, the reaction yield and the reaction time, but considering the quality of the finally obtained polyamide-based resin, a lower temperature is preferable. The reaction rate can also be set arbitrarily. Although the pressure is not limited, it is preferable to reduce the pressure in the system in order to efficiently extract the volatile components out of the system.

The polyamide-based resin may have its ends blocked with a terminal blocking agent such as a carboxylic acid compound and an amine compound, if necessary. When a monocarboxylic acid or monoamine is added to block the ends, the terminal amino group or terminal carboxyl group concentration of the obtained nylon resin is lower than when the terminal blocking agent is not used. On the other hand, when the terminal is blocked with a dicarboxylic acid or diamine, the sum of the concentrations of the terminal amino group and the terminal carboxyl group does not change, but the ratio of the concentrations of the terminal amino group and the terminal carboxyl group changes.

Specific examples of carboxylic acid compounds include, but are not limited to, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, Aliphatic monocarboxylic acids such as myristoleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid and arachidic acid, alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid and methylcyclohexanecarboxylic acid, benzoic acid, toluic acid, ethyl Benzoic acid, aromatic monocarboxylic acids such as phenylacetic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid , tetradecanedioic acid, pentadecanedioic acid, octadecanedioic acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid and other aromatic dicarboxylic acids, etc. mentioned.

Specific examples of amine compounds include, but are not limited to, butylamine, pentylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetra Aliphatic monoamines such as decylamine, pentadecylamine, hexadecylamine, octadecylamine, nonadecylamine and icosylamine; alicyclic monoamines such as cyclohexylamine and methylcyclohexylamine; aromatic monoamines such as benzylamine and β-phenylethylamine; ,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11 -diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane, 1,14-diaminotetradecane, 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1, Aliphatic diamines such as 18-diaminooctadecane, 1,19-diaminononadecane and 1,20-diaminoeicosane; alicyclic diamines such as cyclohexanediamine and bis-(4-aminohexyl)methane; and xylylenediamine. Aromatic diamine etc. are mentioned.

There are no particular restrictions on the terminal group concentration of polyamide-based resins, but when it is necessary to improve dyeability for fiber applications or when designing materials suitable for alloying for resin applications, a higher terminal amino group concentration is recommended. preferable. On the other hand, when it is desired to suppress coloring or gelation under long-term aging conditions, it is preferable that the terminal amino group concentration is low. Furthermore, if you want to suppress lactam regeneration during remelting, thread breakage during melt spinning due to oligomer formation, mold deposit during continuous injection molding, and die mark generation during continuous extrusion of film, both the terminal carboxyl group concentration and the terminal amino group concentration are adjusted. Lower is preferred. The terminal group concentration may be adjusted according to the application, but both the terminal amino group concentration and the terminal carboxyl group concentration are preferably 1.0×10 ⁻⁵ to 15.0×10 −5 eq/g, more preferably 1.0×10 −5 to 15.0×10 ⁻⁵ eq/g. 2.0×10 ^-5 to 12.0×10 ^-5 eq/g, particularly preferably 3.0×10 ^-5 to 11.0×10 ^-5 eq/g. In this specification, the numerical range indicated by "... to ..." includes both end values, like the numerical range indicated by "more than ... less than".

The terminal blocker may be added at the same time as raw materials such as caprolactam at the beginning of the polymerization, added during the polymerization, or added when the molten nylon resin is passed through a vertical stirring thin film evaporator. etc. are adopted. The terminal blocking agent may be added as it is, or may be added after being dissolved in a small amount of solvent.

The polyamide-based resin composition may contain other resins in addition to the polyamide-based resin. Examples of other resins include polyester-based resins, vinyl chloride-based resins, modacrylic-based resins, polycarbonate-based resins, polyolefin-based resins, and polyphenylene sulfide-based resins. These may be used individually by 1 type, and may use 2 or more types together.

The core-sheath composite fiber is mainly composed of one or more polyester-based resins selected from the group consisting of polyalkylene terephthalate and polyalkylene terephthalate-based copolymer polyester for the core from the viewpoint of approximating the feel and appearance of human hair. It is preferably composed of a polyester resin composition as a component, and the sheath is a polyamide resin composition mainly composed of a polyamide resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66. It is more preferable to configure "Polyamide resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66" means a polyamide resin containing 80 mol% or more of nylon 6 and/or nylon 66.

The core-sheath composite fiber may contain a flame retardant from the viewpoint of flame retardancy. Examples of flame retardants include bromine-containing flame retardants and phosphorus-containing flame retardants. Examples of the phosphorus-containing flame retardant include phosphoric acid ester amide compounds and organic cyclic phosphorus compounds. Brominated flame retardants include, but are not limited to, brominated epoxy flame retardants; Bromine-containing phosphate esters such as ethylenebis(tetrabromophthalimide), ethylenebis(pentabromophenyl), octabromotrimethylphenylindane, tris(tribromoneopentyl)phosphate; brominated polystyrenes; brominated polybenzyl acrylates brominated phenoxy resin; brominated polycarbonate oligomers; tetrabromobisphenol A, tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetrabromobisphenol A-bis (allyl ether), tetrabromobisphenol A-bis tetrabromobisphenol A derivatives such as (hydroxyethyl ether); bromine-containing triazine compounds such as tris(tribromophenoxy)triazine; bromine-containing isocyanuric acid compounds such as tris(2,3-dibromopropyl)isocyanurate; be done. Among them, it is preferable to use a brominated epoxy flame retardant from the viewpoint of heat resistance and flame retardancy.

Although the brominated epoxy flame retardant is not particularly limited, for example, it is preferable to include 5 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the main component resin in the core and/or sheath. For example, from the viewpoint of heat resistance and flame retardancy, the core part is 100 parts by weight of one or more polyester resins selected from the group consisting of polyalkylene terephthalate and polyalkylene terephthalate-based copolymer polyester, and 100 parts by weight of brominated epoxy 100 parts by weight of a polyamide resin composed mainly of at least one selected from the group consisting of nylon 6 and nylon 66 for the sheath, and It is preferably composed of a polyamide resin composition containing 5 parts by weight or more and 40 parts by weight or less of a brominated epoxy flame retardant.

The core-sheath composite fiber may contain a flame retardant aid. The flame retardant auxiliary is not particularly limited, but from the viewpoint of flame retardancy, it is preferable to use, for example, an antimony-based compound or a composite metal containing antimony. Examples of antimony-based compounds include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate, potassium antimonate, and calcium antimonate. One or more selected from the group consisting of antimony trioxide, antimony pentoxide, and sodium antimonate is more preferable from the viewpoint of the effect of improving flame retardancy and the effect on touch.

The flame retardant aid is not particularly limited, but for example, it is preferable that the core and/or the sheath contain 0.1 parts by weight or more and 10 parts by weight or less based on 100 parts by weight of the main component resin.

In particular, by adding a flame retardant aid to the polyamide-based resin composition that constitutes the sheath, moderate surface unevenness is formed on the fiber surface, and in addition to flame retardancy, it has a low-gloss appearance similar to that of human hair. A core-sheath composite fiber for artificial hair is easily obtained.

The core-sheath composite fiber may optionally contain various additives such as pigments, heat-resistant agents, stabilizers, fluorescent agents, antioxidants, and antistatic agents within the range that does not impair the effects of the present invention. good too.

The core-sheath composite fiber is not particularly limited, but for example, after melt-kneading each resin composition constituting each of the core-sheath using various general kneaders, a nozzle for core-sheath type composite spinning is used. It can be produced by melt spinning using For example, a polyester resin composition obtained by dry blending each component such as a polyester resin and a brominated epoxy flame retardant is melt-kneaded using various general kneaders to form a core component, while a polyamide resin , a pigment, and a brominated epoxy flame retardant are dry-blended into a polyamide-based resin composition, which is melt-kneaded using a variety of general kneaders to form a sheath component. Examples of kneaders include single-screw extruders, twin-screw extruders, rolls, Banbury mixers, and kneaders. Among them, a twin-screw extruder is preferable from the viewpoint of adjustment of kneading degree and simplicity of operation.

In the melt spinning process, in the case of a polyester resin composition, the temperature of the extruder, gear pump, nozzle, etc. is 250 ° C. or more and 300 ° C. or less, and in the case of a polyamide resin composition, the temperature of the extruder, gear pump, nozzle, etc. 260 ° C. or higher and 320 ° C. or lower, extruded from a nozzle for core-sheath type composite spinning, cooled to below the glass transition point of each resin, for example, 20 m / min or more and 5000 m / min or less, or 30 m / min or more and 2000 m A spun yarn (undrawn yarn) can be obtained by taking it up at a speed of 1/min or less. At the time of melt spinning, the polyester-based resin composition constituting the core is supplied by the core extruder of the melt spinning machine, and the polyamide-based resin composition constituting the sheath is supplied by the sheath extruder of the melt spinning machine. A spun yarn (undrawn yarn) is obtained by supplying the polymer and discharging the molten polymer from a core-sheath type composite spinning nozzle having a predetermined shape.

The spun yarn (undrawn yarn) is preferably hot drawn. The hot drawing may be carried out by either a two-step method in which the spun yarn is once wound up and then drawn, or a direct spinning drawing method in which the spun yarn is continuously drawn without being wound up. Hot drawing is performed by a single-stage drawing method or a multi-stage drawing method of two or more steps.

A heating roller, a heat plate, a steam jet device, a hot water tank, or the like can be used as heating means for hot drawing, and these can be used in combination as appropriate.

The core-sheath composite fiber may be given an oil such as a fiber treatment agent or a softening agent to make the feel and texture more similar to human hair. Examples of fiber treatment agents include silicone-based fiber treatment agents and non-silicone-based fiber treatment agents for improving touch and combability.

The core-sheath composite fiber may be processed by gear crimping. As a result, the fibers are given a gentle bend, a natural appearance is obtained, and the adhesion between the fibers is lowered, so that the combability is improved. In this gear crimping process, the fiber is generally heated to a softening temperature or higher and passed between two meshed gears, and the shape of the gear is transferred to cause the fiber to bend. In addition, if necessary, the core-sheath composite fibers for artificial hair can be heat-treated at different temperatures in the fiber processing stage to develop curls of different shapes.

The fiber bundle can be produced by producing core-sheath composite fibers having different core-sheath ratios, and then mixing two or more types of core-sheath composite fibers with different core-sheath ratios at a predetermined mixing ratio. . Alternatively, a fiber bundle containing core-sheath composite fibers having two or more different core-sheath ratios is produced by using a nozzle having a plurality of hole diameters and land lengths in the core-sheath type composite spinning nozzle (hole). good too. In any case, the obtained fiber bundle may be hacked 20 times or more and 100 times or less, if necessary.

The total fineness of the fiber bundle is not particularly limited, and may be appropriately determined as necessary. 320000 dtex or more and 380000 dtex or less, or 340000 dtex or more and 360000 dtex or less.

<Headdress>
In one or more embodiments of the present invention, the artificial hair fiber bundles described above can be used without particular limitation as long as they are headdress products. For example, it can be used for hair wigs, wigs, weaving, hair extensions, braided hair, hair accessories and doll hair.

The artificial hair fiber bundle described above may be used alone as artificial hair, or may be used in combination with other artificial hair fibers or natural fibers such as human hair and animal hair. Examples of other artificial hair fibers include acrylic fibers and vinyl chloride fibers.

In one or more embodiments of the present invention, the headdress product may be composed only of the artificial hair fiber bundles of one or more embodiments of the present invention. In addition, the head ornament product may be configured by combining the artificial hair fiber bundle of one or more embodiments of the present invention with other artificial hair fibers or natural fibers such as human hair and animal hair.

Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to these examples.

The measurement methods and evaluation methods used in Examples and Comparative Examples are as follows.

(Cross section of fiber bundle)
The fibers were bundled at room temperature (23° C.), fixed with a shrinkable tube so that the fiber bundle would not shift, and cut into round slices with a cutter to prepare a fiber bundle for cross-sectional observation. This fiber bundle was photographed with a laser microscope (manufactured by Keyence Corporation, "VK-9500") at a magnification of 500 to obtain a cross-sectional photograph.
Using the obtained cross-sectional photograph of the fiber bundle, a region containing about 100 fibers is randomly selected as a measurement region, and an image analysis device (manufactured by Mitani Shoji Co., Ltd., image analysis software "Win ROOF") is used. , the areas of the fiber cross-section, the core cross-section and the sheath cross-section of each core-sheath composite fiber were calculated, and the core-sheath ratio was calculated based thereon. This makes it possible to confirm the types of fibers with different core-sheath ratios contained in the fiber bundle. Also, the standard deviation of the cross-sectional area ratio of the core in the fiber bundle was calculated using the following formula (1).

(Curl set property)
At room temperature (23 ° C.), the haired filament is wound around a φ32 mm pipe, curled at 120 ° C. for 60 minutes, aged at room temperature (23 ° C.) for 60 minutes, and then fixed at one end of the curled filament. Measure the filament length after hanging and curl setting. The length of the filament was used as an index of curl setting, and it was determined that curl setting was possible when the length was 17.0 cm or less.

(tactile sensation)
A sensory evaluation was performed by a professional beautician, and evaluation was made according to the following three-grade criteria.
A: Very good tactile feel equivalent to human hair B: Slightly inferior to human hair but good tactile feel C: Poor tactile feel inferior to human hair

(combability)
The fibers were cut to a length of 70 cm while the curl was completely stretched, and 25 g of the obtained fibers having a fiber length of 70 cm were bundled. After that, the center of the fiber bundle was bound with a string, folded in two, and the string portion was fixed to prepare a fiber bundle for hair ironing. Next, with a hair iron ("IZUNAMI ITC450 flat iron" manufactured by IZUNAMI INC., USA) heated to 180°C, the heating operation is performed 5 times while crimping from the root to the tip of the hair fixing the fiber bundle. A fiber bundle for evaluation of combability was repeatedly produced. After that, a hair comb (made in Germany, "MATADOR PROFESSIONAL 386.8 1/2F") was used to comb the hair 100 times from the root to the tip where the fiber bundle for evaluating combability was fixed, and the hair was deformed. Alternatively, the combability was evaluated according to the following three-grade criteria from the number of split fibers.
A: Less than 10 fibers were deformed or split after passing through the comb 100 times, and the comb passed without resistance until the end. B: 10 or more but less than 30 fibers were deformed or split after passing through the comb 100 times. Level C: The number of fibers deformed or split after passing through the comb 100 times is 30 or more.

(Appearance evaluation)
The appearance of the fibers in Examples and Comparative Examples was sensory evaluated by a professional beautician and evaluated according to the following three-grade criteria.
A: Appearance equivalent to human hair B: Appearance almost equivalent to human hair C: Appearance inferior to human hair

(durability)
A hair sample (fiber bundle) was damaged by the following procedure, and the durability was evaluated by the bulk change rate calculated from the bulk values before and after the damage.
(1) A hair sample (total length: 16 inches, total length: 16 inches, 15 g) of the layer portion (4 inches) was measured for initial bulkiness.
(2) The hair was tangled by raising the hair up against the sample for hair with a brush.
(3) The roots were rubbed 10 times, the layered portion 10 times, and the entire hair 10 times by hand to further tangle the hair.
(4) The tangled hair was combed out with a brush.
(5) The operations (2) to (4) were repeated 10 times to promote damage.
(6) The bulk value of the layered portion of the hair sample after accelerated damage was measured and taken as the bulk value after damage.
(7) Based on the following formula (4), the bulk height change rate before and after damage was calculated and evaluated according to the following three-level criteria.
Bulk height change rate after damage (%) = Bulk value after damage/Initial bulk value x 100 (4)
A: Bulk height change rate is less than 200% B: Bulk height change rate is 200% or more and less than 250% C: Bulk height change rate is 250% or more (measurement of bulky value)
The bulkiness value of the hair sample (fiber bundle) was measured using the bulkiness measuring instrument shown in FIGS. 5A to 5C. As shown in FIGS. 5A to 5C, the bulk measuring machine 100 includes a support base 101 and

clippers

102 and 103 arranged on the support base 101 to clamp hair. A scale 104 is attached to the clip 102 with a transparent tape (not shown). The support base 101 and the

clamps

102 and 103 are all made of acrylic resin. As shown in FIG. 5C, the hair sample 40 is placed between the clip 102 and the clip 103 so that the longitudinal center of the clip 102 coincides with the center of the layered portion of the hair sample 40. The bulkiness value was measured after placement.

(Production example 1)
Polyethylene terephthalate pellets (manufactured by East West Chemical Private Limited, EastPET trade name "A-12") 100 parts by weight, brominated epoxy flame retardant (manufactured by Sakamoto Yakuhin Kogyo, trade name "SR-T2MP") 30 parts by weight, Sodium antimonate (manufactured by Nippon Seiko, trade name "SA-A") 3 parts by weight, black pigment masterbatch (manufactured by Dainichiseika Kogyo, trade name "PESM22367BLACK (20)") 2.1 parts by weight, yellow pigment master Batch (manufactured by Dainichiseika Kogyo, trade name "PESM1001YELLOW (20)") 0.8 parts by weight, and red pigment masterbatch (manufactured by Dainichiseika Kogyo, trade name "PESM3005RED (20)") 0.6 parts by weight After adding and dry-blending, it was supplied to a twin-screw extruder, melt-kneaded at a barrel setting temperature of 280° C., and pelletized to obtain a polyester-based resin composition.
Subsequently, for 100 parts by weight of nylon 6 (manufactured by Unitika, product name "A1030BRL"), brominated epoxy flame retardant (manufactured by Sakamoto Chemical Industry, product name "SR-T2MP") 12 parts by weight, sodium antimonate (Japan Seiko, trade name "SA-A") 2 parts by weight, black pigment masterbatch (manufactured by Dainichiseika Kogyo, trade name "PESM22367BLACK (20)") 2.1 parts by weight, yellow pigment masterbatch (Dainichiseika Kogyo, trade name "PESM1001 YELLOW (20)") 0.8 parts by weight, and red pigment masterbatch (manufactured by Dainichiseika Kogyo, trade name "PESM3005RED (20)") 0.6 parts by weight are added and dry blended. After that, it was supplied to a twin-screw extruder, melt-kneaded at a barrel setting temperature of 260° C., and pelletized to obtain a polyamide resin composition.
Next, the obtained pellet-like polyester resin composition and polyamide resin composition are supplied to an extruder, respectively, and the core-sheath type composite spinning nozzle (hole) having a flat two-leaf shape is used at a nozzle setting temperature of 270 ° C. Extruded and wound at a speed of 40 to 200 m / min, the polyester-based resin composition as the core, the polyamide-based resin composition as the sheath, and the core-sheath ratio is the area ratio core: sheath = 8:2. An undrawn yarn of the core-sheath composite fiber was obtained.
The obtained undrawn yarn was drawn at a speed of 45 m/min using a heat roll at 85°C and drawn to make a 3-fold drawn yarn, and continuously heated to 205°C at 45 m/min using a heat roll. The fiber is wound up at a speed of , and heat-treated, and the polyether-based oil agent (manufactured by Marubishi Yuka Kogyo Co., Ltd., trade name “KWC-Q”) is added to 0.20% omf (weight percentage of pure oil agent relative to dry fiber weight). After adhering, it was dried to obtain a core-sheath composite fiber (single fiber fineness: 64 dtex).

(Production example 2)
A core-sheath composite fiber (single fiber fineness 62 dtex) was obtained in the same manner as in Production Example 1, except that the core-sheath ratio was set to core:sheath=7:3 in area ratio.

(Production example 3)
A core-sheath composite fiber (single fiber fineness 60 dtex) was obtained in the same manner as in Production Example 1, except that the core-sheath ratio was set to core:sheath=6:4 in area ratio.

(Production example 4)
A core-sheath composite fiber (single fiber fineness of 58 dtex) was obtained in the same manner as in Production Example 1, except that the core-sheath ratio was set to core:sheath=5:5 in terms of area ratio.

(Production example 5)
A core-sheath composite fiber (single fiber fineness of 57 dtex) was obtained in the same manner as in Production Example 1, except that the core-sheath ratio was set to core:sheath=4:6 in area ratio.

(Production example 6)
A core-sheath composite fiber (single fiber fineness of 55 dtex) was obtained in the same manner as in Production Example 1, except that the core-sheath ratio was set to core:sheath=3:7 in terms of area ratio.

(Production Example 7)
A core-sheath composite fiber ( A single fiber fineness of 64 dtex) was obtained.

(Production Example 8)
A core-sheath composite fiber (single fiber fineness of 55 dtex) was obtained in the same manner as in Production Example 7, except that the core-sheath ratio was set to core:sheath=3:7 in area ratio.

(Production Example 9)
Polybutylene terephthalate pellets (manufactured by Mitsubishi Chemical Corporation, trade name "Novaduran 5020") are used as the resin for the core, and the polyester resin composition obtained by melt-kneading at a barrel setting temperature of 260 ° C. and pelletizing is used as the core. A core-sheath composite fiber (single fiber fineness: 64 dtex) was obtained in the same manner as in Production Example 1, except that the nozzle temperature was set to 260°C.

(Production Example 10)
A core-sheath composite fiber (single fiber fineness 62 dtex) was obtained in the same manner as in Production Example 9, except that the core-sheath ratio was set to core:sheath=7:3 in area ratio.

(Production Example 11)
A core-sheath composite fiber (single fiber fineness 60 dtex) was obtained in the same manner as in Production Example 9, except that the core-sheath ratio was set to core:sheath=6:4 in area ratio.

(Production Example 12)
A core-sheath composite fiber (single fiber fineness of 58 dtex) was obtained in the same manner as in Production Example 9, except that the core-sheath ratio was set to core:sheath=5:5 in area ratio.

(Production Example 13)
A core-sheath composite fiber (single fiber fineness of 57 dtex) was obtained in the same manner as in Production Example 9, except that the core-sheath ratio was set to core:sheath=4:6 in area ratio.

(Production Example 14)
A core-sheath composite fiber (single fiber fineness of 55 dtex) was obtained in the same manner as in Production Example 9, except that the core-sheath ratio was set to core:sheath=3:7 in area ratio.

(Example 1)
The core-sheath conjugate fibers of Production Examples 2 and 6 were cut out to an arbitrary length so that the weight ratio was 50:50 and layered. A double hack ring was performed to obtain fiber bundles composed of two types of core-sheath composite fibers with different core-sheath ratios. In the obtained fiber bundles, the number ratio of the core-sheath composite fibers of Production Examples 2 and 6 is almost equal to the weight ratio. , can be obtained as follows. The core cross-sectional area ratios of the core-sheath composite fibers of Production Examples 2 and 6 are 0.7 and 0.3, respectively, and the average value of the core cross-sectional area ratios is 0.5. The standard deviation can be obtained as follows and is 0.20.

(Example 2)
Core-sheath composite fibers with three different core-sheath ratios were prepared in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 2, 4 and 6 were used in a weight ratio of 33:33:33. A fiber bundle consisting of In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 2, 4 and 6 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio is calculated by the same calculation method as in Example 1. can be done.

(Example 3)
In the same manner as in Example 1, except that the core-sheath composite fibers of Production Examples 1 to 6 were used so that the weight ratio was 10:10:10:10:10:50, six types of different core-sheath ratios were produced. A fiber bundle composed of core-sheath composite fibers was obtained. In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 1 to 6 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

(Example 4)
Fiber bundles composed of two types of core-sheath composite fibers with different core-sheath ratios were prepared in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 7 and 8 were used at a weight ratio of 90:10. got In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 7 and 8 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

(Example 5)
Six types of different core-sheath ratios were produced in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 9 to 14 were used at a weight ratio of 16:16:16:16:16:16. A fiber bundle composed of core-sheath composite fibers was obtained. In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 9 to 14 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

(Comparative example 1)
A fiber bundle was obtained in the same manner as in Example 1, except that only the core-sheath composite fiber of Production Example 4 was used.

(Comparative example 2)
Made of core-sheath composite fibers with three different core-sheath ratios in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 3 to 5 were used at a weight ratio of 70:20:10. A fiber bundle was obtained. In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 3 to 5 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

(Comparative Example 3)
Five different core-sheath ratios were produced in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 1 to 5 were used at a weight ratio of 5:10:10:10:65. A fiber bundle composed of composite fibers was obtained. In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 1 to 5 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

(Comparative Example 4)
Fiber bundles composed of two types of core-sheath composite fibers with different core-sheath ratios were prepared in the same manner as in Example 1 except that the core-sheath composite fibers of Production Examples 1 and 6 were used at a weight ratio of 95:5. got In the obtained fiber bundle, the number ratio of the core-sheath composite fibers of Production Examples 1 and 6 is almost equal to the weight ratio, and the standard deviation of the core cross-sectional area ratio can be calculated by the same calculation method as in Example 1. .

The fiber cross-sectional shape, curl set property, touch, combability, appearance and durability of the fiber bundles of Examples and Comparative Examples were measured and evaluated as described above. The results are shown in Table 1 below and FIGS.

FIG. 2 is a laser micrograph of the fiber cross section of the fiber bundle of Example 1. As can be seen from FIG. 2, the fiber bundle contains two types of core-sheath composite fibers with different core-sheath ratios. FIG. 3 is a laser microscope photograph of a fiber cross section of the fiber bundle of Example 2. FIG. As can be seen from FIG. 3, the fiber bundle contains three types of core-sheath composite fibers with different core-sheath ratios. 4 is a laser micrograph of a fiber cross section of the fiber of Comparative Example 1. FIG. As can be seen from FIG. 4, the fiber bundle consists of core-sheath composite fibers having the same core-sheath ratio.

As can be seen from Table 1, the fiber bundles of Examples 1 to 5 had good curl-set properties, had a touch similar to human hair, combability, and appearance, and had good durability.

On the other hand, the fiber bundle of Comparative Example 1, which is composed only of core-sheath composite fibers with a core-sheath ratio of 5:5, had good tactile feel, combability, and durability, but had poor curl-set properties and appearance. A comparative example composed of three types of core-sheath composite fibers with different core-sheath ratios, but having a standard deviation of 0.07 in the ratio of the core cross-sectional area to the fiber cross-sectional area of the core-sheath composite fibers constituting the fiber bundle. The fiber bundle of No. 2 had good tactile feel, combability and durability, but had poor curl set properties and appearance. A comparative example in which the standard deviation of the ratio of the core cross-sectional area to the fiber cross-sectional area of the core-sheath composite fibers constituting the fiber bundle is 0.13, although it is composed of five types of core-sheath composite fibers with different core-sheath ratios. Fiber No. 3 had good tactile feel, combability and durability, but had poor curl set properties and appearance. A comparative example composed of two types of core-sheath composite fibers with different core-sheath ratios, but having a standard deviation of 0.11 in the ratio of the core cross-sectional area to the fiber cross-sectional area of the core-sheath composite fibers constituting the fiber bundle. The fibers of No. 4 had good curl set properties, but poor touch, combability, appearance and durability.

The present invention is not particularly limited, but may include at least the following embodiments.
[1] A fiber bundle for artificial hair containing core-sheath composite fibers having two or more different core-sheath ratios,
Each core-sheath composite fiber includes a core portion and a sheath portion, and the core-sheath ratio is expressed by the area ratio of the core portion and the sheath portion,
In each core-sheath composite fiber, the core is composed of a polyester-based resin composition containing a polyester-based resin, and the sheath is composed of a polyamide-based resin composition containing a polyamide-based resin,
A fiber bundle for artificial hair, wherein the standard deviation of the ratio of the cross-sectional area of the core to the cross-sectional area of the core-sheath composite fibers constituting the fiber bundle for artificial hair is 0.15 or more.
[2] The fiber bundle for artificial hair according to [1], wherein each core-sheath composite fiber has a core-sheath ratio of 3:7 to 8:2 in terms of area ratio of core:sheath.
[3] According to [1] or [2], the content of the core-sheath composite fibers having the same core-sheath ratio is 5% by weight or more and 90% by weight or less with respect to the total weight of the fiber bundle for artificial hair. fiber bundle for artificial hair.
[4] The fiber bundle for artificial hair according to any one of [1] to [3], wherein each of the core-sheath composite fibers has a flattened cross-sectional shape.
[5] The fiber bundle for artificial hair according to any one of [1] to [4], wherein in each of the core-sheath composite fibers, the core has a flattened cross-sectional shape.
[6] Any one of [1] to [5], wherein the polyester-based resin contains one or more polyester-based resins selected from the group consisting of polyalkylene terephthalate and copolyester mainly composed of polyalkylene terephthalate. A fiber bundle for artificial hair as described.
[7] The artificial hair fiber according to any one of [1] to [6], wherein the polyamide-based resin contains a polyamide-based resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66. bundle.
[8] The artificial hair fiber according to any one of [1] to [7], wherein each of the core-sheath composite fibers has a fiber cross section with a concentric structure in which the center position of the core portion coincides with the center position of the fiber. bundle.
[9] The fiber bundle for artificial hair according to any one of [1] to [8], wherein each of the core-sheath composite fibers has a single fiber fineness of 10 dtex or more and 150 dtex or less.
[10] The fiber bundle for artificial hair according to any one of [1] to [9], wherein the total fineness of the fiber bundle for artificial hair is 30,000 dtex or more and 400,000 dtex or less.
[11] A headdress product comprising the artificial hair fiber bundle according to any one of [1] to [10].
[12] The headdress product according to [11], wherein the headdress product is one selected from the group consisting of hair wigs, wigs, weaving, hair extensions, braided hair, hair accessories and doll hair.

1 Sheath-core composite fiber for artificial hair (cross section)
10 Sheath 20 Core 100 Bulk height measuring device 40 Hair sample (fiber bundle)
101 supports 102, 103 clip 104 scale

Claims

A fiber bundle for artificial hair containing core-sheath composite fibers having two or more different core-sheath ratios,
Each core-sheath composite fiber includes a core portion and a sheath portion, and the core-sheath ratio is expressed by the area ratio of the core portion and the sheath portion,
In each core-sheath composite fiber, the core is composed of a polyester-based resin composition containing a polyester-based resin, and the sheath is composed of a polyamide-based resin composition containing a polyamide-based resin,
A fiber bundle for artificial hair, wherein the standard deviation of the ratio of the cross-sectional area of the core to the cross-sectional area of the core-sheath composite fibers constituting the fiber bundle for artificial hair is 0.15 or more.
The fiber bundle for artificial hair according to claim 1, wherein each of the core-sheath composite fibers has a core-sheath ratio of 3:7 to 8:2 in terms of area ratio of core:sheath.
3. The fiber for artificial hair according to claim 1, wherein the content of the core-sheath composite fiber having the same core-sheath ratio is 5% by weight or more and 90% by weight or less with respect to the total weight of the fiber bundle for artificial hair. bundle.
The fiber bundle for artificial hair according to any one of claims 1 to 3, wherein each of the core-sheath composite fibers has a flat cross-sectional shape.
The fiber bundle for artificial hair according to any one of claims 1 to 4, wherein the core portion of each of the core-sheath composite fibers has a flat cross-sectional shape.
The artificial hair according to any one of claims 1 to 5, wherein the polyester-based resin contains one or more polyester-based resins selected from the group consisting of polyalkylene terephthalate and copolymerized polyester mainly composed of polyalkylene terephthalate. fiber bundle.
The fiber bundle for artificial hair according to any one of claims 1 to 6, wherein the polyamide-based resin contains a polyamide-based resin mainly composed of at least one selected from the group consisting of nylon 6 and nylon 66.
The fiber bundle for artificial hair according to any one of claims 1 to 7, wherein each of the core-sheath composite fibers has a fiber cross section with a concentric structure in which the center position of the core portion coincides with the center position of the fiber.
The fiber bundle for artificial hair according to any one of claims 1 to 8, wherein each of the core-sheath composite fibers has a single fiber fineness of 10 dtex or more and 150 dtex or less.
The fiber bundle for artificial hair according to any one of claims 1 to 9, wherein the total fineness of the fiber bundle for artificial hair is 30,000 dtex or more and 400,000 dtex or less.
A headdress product containing the artificial hair fiber bundle according to any one of claims 1 to 10.
The headdress product according to claim 11, wherein the headdress product is one selected from the group consisting of hair wigs, wigs, weaving, hair extensions, braided hair, hair accessories and doll hair.