Artificial hair fiber

Abstract

The present invention addresses the problem of providing an artificial hair fiber that achieves both appropriate non-slipperiness and smoothness of combing, that further has excellent moist feeling, and that is less susceptible to changes in hue even through hot water treatment.　One embodiment of the present invention is an artificial hair fiber having a base material fiber and a surface treatment agent adhering to at least a part of the surface of the base material fiber. The surface treatment agent contains a hydrophilic polyol and a cationic surfactant. Let that the amount of the artificial hair fiber is 100 mass%, the total attached amount of the hydrophilic polyol and the cationic surfactant is 0.03-0.30 mass%.

Description

Artificial hair fibers

[0001] The present invention relates to a fiber for artificial hair.

[0002] Artificial hair is becoming increasingly important as an alternative to human hair in hair accessories such as wigs, hair accessories, hair bands, doll hair, etc. Materials for artificial hair fibers include acrylic resins, vinyl chloride resins, and polyester resins, and artificial hair fibers made from these resins are commercially available.

[0003] Patent Document 1 discloses a technology for treating base fibers with a specified fiber treatment agent, with the aim of providing a fiber treatment agent that gives the fibers good luster and smoothness, prevents the fibers from squeaking, and provides excellent volume, even when the fibers are made of vinyl chloride resin.

[0004] Japanese Patent Application Laid-Open No. 2002-285470

[0005] Fibers for artificial hair are required to have both moderate slip resistance and combability in order to prevent discomfort to the user. Furthermore, fibers for artificial hair are required to have an excellent moist feel that is closer to that of natural hair fibers. Here, the slip resistance of fibers refers to the degree to which fibers do not slip when braiding a fiber bundle. The combability of fibers refers to the degree to which fingers can be easily combed through a fiber bundle by hand. The moist feel refers to the degree of softness when the fiber bundle is pressed against the palm of the hand.

[0006] Furthermore, depending on the application, artificial hair fibers may be subjected to hot water treatment by immersing them in hot water after braiding or other processing, but the color of the artificial hair fibers may change after the hot water treatment.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a fiber for artificial hair that has both suitable slipperiness and combability, and also has an excellent moist feel, and whose color does not change easily even after hot water treatment.

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by adjusting the composition of the surface treatment agent attached to the base fiber, and have thus completed the present invention.

[0009] According to the present invention, the following are provided: [1] An artificial hair fiber having a base fiber and a surface treatment agent adhered to at least a portion of the surface of the base fiber, wherein the surface treatment agent comprises a hydrophilic polyhydric alcohol and a cationic surfactant, and the total amount of the hydrophilic polyhydric alcohol and the cationic surfactant adhered is 0.03 to 0.30 mass% when the artificial hair fiber is taken as 100 mass%. [2] The artificial hair fiber according to [1], wherein the content of the cationic surfactant in the surface treatment agent is 0.5 to 3.0 mass parts when the hydrophilic polyhydric alcohol is taken as 10 mass parts. [3] The cationic surfactant comprises a quaternary ammonium salt having a cation represented by the following formula (1), In formula (1), R １ , R ２ , R ３ and R ４ are each independently a monovalent organic group. [4] The artificial hair fiber according to any one of [1] to [3], wherein the artificial hair fiber has a fineness of 40 to 50 d and a Young's modulus of 3,500 MPa or less. [5] The artificial hair fiber according to any one of [1] to [4], wherein the base fiber contains at least one selected from the group consisting of a vinyl chloride homopolymer, a vinyl chloride-acrylonitrile copolymer, polyethylene terephthalate, a polyamide resin, polypropylene, and an acrylonitrile-styrene copolymer.

[0010] According to the present invention, it is possible to provide a fiber for artificial hair that has both moderate slipperiness and combability, and also has an excellent moist feel, and whose color does not change easily even after hot water treatment.

[0011] The present invention will be described in detail below. The present invention is not limited to these descriptions. The features of the following embodiments can be combined with each other. Furthermore, each feature can be an invention independently. Furthermore, elements in the following embodiments that are not defined in the claims are optional elements and can be omitted. In this specification, a single "0" may be added to the end of a numerical value. For example, adding a "0" after "1.4" may result in "1.40."

[0012] <Explanation of Terms> In this specification, for example, the expression "X to Y" means that X or more and Y or less.

[0013] 1. Artificial Hair Fiber The artificial hair fiber according to this embodiment comprises a base fiber and a surface treatment agent adhered to at least a portion of the surface of the base fiber.

[0014] 1.1 Base Fiber For the base fiber according to this embodiment, for example, a resin such as a vinyl chloride resin, a polyester resin, a polyamide resin, or a polyolefin resin can be used. These resins may be used alone or in combination of two or more. Furthermore, if necessary, a resin composition containing additives may be added to these resins to form a synthetic fiber spun.

[0015] 1.1.1 Resin 1.1.1.1 Vinyl chloride resin Examples of the vinyl chloride resin according to this embodiment include a vinyl chloride homopolymer, a chlorinated vinyl chloride homopolymer, and a vinyl chloride copolymer. These vinyl chloride resins may be used alone or in combination of two or more.

[0016] Examples of vinyl chloride copolymers include copolymers of vinyl chloride and vinyl esters, such as vinyl chloride-vinyl acetate copolymer and vinyl chloride-vinyl propionate copolymer; copolymers of vinyl chloride and acrylic esters, such as vinyl chloride-butyl acrylate copolymer and vinyl chloride-2-ethylhexyl acrylate copolymer; copolymers of vinyl chloride and olefins, such as vinyl chloride-ethylene copolymer and vinyl chloride-propylene copolymer; and vinyl chloride-acrylonitrile copolymer.

[0017] As the vinyl chloride resin according to this embodiment, a vinyl chloride homopolymer and a vinyl chloride-acrylonitrile copolymer are preferred. When these resins are used, the processability of the base fiber is improved, and the artificial hair fiber has a softer feel.

[0018] 1.1.1.2 Polyester-Based Resin Examples of polyester-based resins according to this embodiment include aromatic polyester-based resins such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and aliphatic polyester resins such as polylactic acid, polyhydroxybutyric acid, polycaprolactone, polybutylene succinate, polybutylene adipate, polyethylene succinate, polyglycolic acid, poly-3-hydroxypropionate, and poly-3-hydroxybutyrate. These polyester-based resins may be used alone or in combination of two or more.

[0019] The polyester resin according to this embodiment is preferably polyethylene terephthalate, since the strength and heat resistance of the artificial hair fiber are improved when such a resin is used.

[0020] 1.1.1.3 Polyamide-Based Resin Examples of polyamide-based resins according to this embodiment include nylon 6, nylon 66, nylon 11, nylon 12, nylon 6.10, nylon 6.12, and copolymers thereof. These polyamide-based resins may be used alone or in combination of two or more.

[0021] 1.1.1.4 Polyolefin Resin Examples of the polyolefin resin according to this embodiment include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-propylene copolymer. These polyolefin resins may be used alone or in combination of two or more.

[0022] The polyolefin resin according to this embodiment is preferably polypropylene. When such a resin is used, the specific gravity of the artificial hair fiber is reduced, resulting in a lighter weight during use and an excellent feel when used.

[0023] 1.1.1.5 Other Resins Examples of other resins that may be used in this embodiment include copolymers of ethylene and vinyl alcohol, acrylonitrile-styrene copolymers, acrylonitrile-styrene-butadiene terpolymers, and ethylene-ethyl (meth)acrylate copolymers.

[0024] Among the resins described above, the resin according to the present embodiment preferably contains one or more resins selected from the group consisting of vinyl chloride homopolymer, vinyl chloride-acrylonitrile copolymer, polyethylene terephthalate, polyamide resin, polypropylene, and acrylonitrile-styrene copolymer, and more preferably consists solely of one or more resins selected from the above group. The use of such a resin improves the processability of the base fiber and provides the artificial hair fiber bundle with a more appropriate degree of slip resistance. Furthermore, since the artificial hair fiber has a softer feel, the resin according to the present embodiment preferably contains a vinyl chloride homopolymer or a vinyl chloride-acrylonitrile copolymer. When the base fiber is taken as 100% by mass, the resin preferably comprises 50% by mass or more, and more preferably 70% by mass or more, of this resin.

[0025] When the base fiber according to this embodiment is taken as 100% by mass, the content of resins other than the above-mentioned resins is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. In other words, when the base fiber is taken as 100% by mass, the total content of vinyl chloride resins, polyester resins, polyamide resins, polyolefin resins, and the other resins is preferably 80% by mass or more. Furthermore, when the base fiber is taken as 100% by mass, the total content of vinyl chloride homopolymers, vinyl chloride-acrylonitrile copolymers, polyethylene terephthalate, polyamide resins, polypropylene, and acrylonitrile-styrene copolymers is preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0026] 1.1.2 Other Components The base fiber according to this embodiment can also be a resin composition to which other components are added as needed. Examples of other components include stabilizers, antistatic agents, heat stabilizers, lubricants, colorants, processing aids, plasticizers, reinforcing agents, UV absorbers, antioxidants, fillers, flame retardants, pigments, initial coloring improvers, conductivity imparting agents, and fragrances. The resin composition according to this embodiment can contain, for example, preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less of other components per 100 parts by mass of resin.

[0027] The resin composition according to the present embodiment preferably contains a colorant. Examples of colorants include carbon black. The resin composition according to the present embodiment may contain 0.1 to 5 parts by mass of the colorant (particularly carbon black) relative to 100 parts by mass of the resin contained in the resin composition, and more preferably 0.1 to 1 part by mass. The content of the colorant (particularly carbon black) relative to 100 parts by mass of the resin contained in the resin composition is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 parts by mass, and may be within a range between any two of the numerical values ​​exemplified here.

[0028] 1.1.3 Shape of Base Fiber The cross-sectional shape perpendicular to the longitudinal direction of the base fiber according to this embodiment (hereinafter simply referred to as "cross-sectional shape") is not particularly limited, but can be any one selected from a circle, an ellipse, a bilobal shape formed by joining two C-shaped portions, a trilobal shape formed by joining three C-shaped portions, a tetralobal shape formed by joining four or more C-shaped portions, a substantially triangular shape, a substantially square shape, a substantially polygonal shape, a Y-shaped shape formed by joining three I-shaped portions, and a cross shape formed by joining four I-shaped portions. The cross-sectional shape of the base fiber is preferably a bilobal shape. Such a cross-sectional shape of the base fiber reduces the bending rigidity of the base fiber, thereby improving the softness of the artificial hair fiber and ultimately improving the moist feel.

[0029] Furthermore, the base fiber according to this embodiment may be a solid fiber as described above, or may be a hollow fiber having a hollow portion extending in the longitudinal direction. In this specification, a "hollow portion" refers to a portion that extends continuously for 3 cm or more in the longitudinal direction of the base fiber and has a major diameter of 1 μm or more in the fiber cross section. The base fiber may have hollow portions of 3 cm or more (preferably 4 cm, 5 cm, or 10 cm) in the longitudinal direction, interspersed with non-hollow portions of 1 cm or less (preferably 0.5 cm). The hollow portions may extend continuously for 10 cm or more in the longitudinal direction of the base fiber. In this case, it is preferable that 80% (preferably 90%) or more of the total length of the base fiber in the longitudinal direction be hollow. Furthermore, a cross section perpendicular to the longitudinal direction of the base fiber may have multiple hollow portions. Therefore, the cross-sectional shape of the base fiber according to this embodiment includes a donut shape (circular outer edge, one hollow), a glasses shape (bilobed outer edge, two hollows), and the like.

[0030] 1.2 Surface Treatment Agent The surface treatment agent according to this embodiment contains a hydrophilic polyhydric alcohol and a cationic surfactant. The use of a hydrophilic polyhydric alcohol improves the slipperiness and moist feel of the artificial hair fiber. The use of a cationic surfactant gives the artificial hair fiber excellent antistatic properties, improving combability.

[0031] The amount of the surface treatment agent according to this embodiment can be 0.03 to 0.30% by mass, more preferably 0.05 to 0.30% by mass, and even more preferably 0.10 to 0.20% by mass, based on 100% by mass of the artificial hair fiber. The amount of the surface treatment agent may be, for example, 0.03, 0.05, 0.10, 0.15, 0.20, 0.25, or 0.30% by mass, based on 100% by mass of the artificial hair fiber, or may be within a range between any two of the values ​​exemplified here. When the amount of the surface treatment agent is equal to or greater than the lower limit, the artificial hair fiber exhibits good tackiness and a more appropriate degree of slipperiness. Furthermore, the artificial hair fiber exhibits excellent moisture retention, resulting in a more moisturized feel. When the amount of the surface treatment agent is equal to or less than the upper limit, the artificial hair fiber is less sticky, less likely to stick to itself, and exhibits better combability. Furthermore, when the amount of the surface treatment agent is below the upper limit, the color of the artificial hair fiber is less likely to change even after hot water treatment. The reason for this is thought to be that when the amount of the surface treatment agent (especially the hydrophilic component) on the surface of the base fiber is below a predetermined value, moisture is less likely to penetrate into the base fiber during hot water treatment, and cavities are less likely to form in the fiber after drying.

[0032] The total adhesion amount of the hydrophilic polyhydric alcohol and cationic surfactant according to this embodiment can be 0.03 to 0.30% by mass, more preferably 0.05 to 0.30% by mass, and even more preferably 0.10 to 0.20% by mass, based on 100% by mass of the artificial hair fiber. The total adhesion amount of the hydrophilic polyhydric alcohol and cationic surfactant may be, for example, 0.03, 0.05, 0.10, 0.15, 0.20, 0.25, or 0.30% by mass, based on 100% by mass of the artificial hair fiber, or may be within a range between any two of the values ​​exemplified here. When the total adhesion amount of the hydrophilic polyhydric alcohol and cationic surfactant is equal to or greater than the lower limit, the artificial hair fiber has excellent moisture retention, resulting in an improved moist feel. When the total adhesion amount of the hydrophilic polyhydric alcohol and cationic surfactant is equal to or less than the upper limit, the stickiness of the artificial hair fiber is suppressed, preventing sticking of the fibers together and improving combability. Furthermore, when the total amount of the hydrophilic polyhydric alcohol and the cationic surfactant attached is equal to or less than the upper limit, the color of the artificial hair fiber is less likely to change even after hot water treatment.

[0033] 1.2.1 Hydrophilic Polyhydric Alcohols Examples of hydrophilic polyhydric alcohols according to this embodiment include polyalkylene glycols, glycerin, diglycerin, polyvinyl alcohol, etc. Examples of polyalkylene glycols according to this embodiment include polyethylene glycol and polypropylene glycol, etc. Here, "hydrophilic" means that the solubility in water is 5% by mass or more at 20°C. Furthermore, the term "hydrophilic polyhydric alcohol" as used herein does not include ionic surfactants. The hydrophilic polyhydric alcohol according to this embodiment preferably includes one or more selected from the group consisting of polyalkylene glycols, glycerin, diglycerin, and polyvinyl alcohol, and more preferably one or more selected from the above group. The use of these hydrophilic polyhydric alcohols increases the coefficient of friction against highly hydrophilic surfaces (e.g., fingertips), thereby providing artificial hair fibers with more appropriate slip resistance. Furthermore, because these hydrophilic polyhydric alcohols also contain hydrophobic moieties, the artificial hair fibers have excellent moisture retention and a more moist feel.

[0034] The average degree of polymerization of the polyalkylene glycol according to this embodiment is preferably 3 to 50, more preferably 3 to 30, and even more preferably 3 to 10. When the average degree of polymerization of the polyalkylene glycol is within this range, the artificial hair fiber has more appropriate slip resistance, and furthermore, the artificial hair fiber has excellent moisture retention, resulting in an improved moist feeling.

[0035] The degree of polymerization of the polyvinyl alcohol according to this embodiment is preferably 2500 or less, more preferably 2000 or less, and even more preferably 1800 or less. The degree of saponification of the polyvinyl alcohol according to this embodiment is preferably 98 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less. The use of such polyvinyl alcohol provides an appropriate viscosity for the surface treatment agent, making it easier to apply to the base fiber, and providing the artificial hair fiber with more appropriate slip resistance.

[0036] 1.2.2 Cationic Surfactant The cationic surfactant according to this embodiment preferably contains a quaternary ammonium salt having a cation represented by the following formula (1). Here, in formula (1), R １ , R ２ , R ３ and R ４ are each independently a monovalent organic group. When such a cationic surfactant is used, the artificial hair fiber has excellent antistatic properties and is easier to comb.

[0037] Examples of cationic surfactants according to this embodiment include quaternary ammonium salts having an oxyalkylene group, and quaternary ammonium salts having an alkyl group, such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, and alkyldimethylethylammonium salts. These cationic surfactants may be used alone or in combination of two or more. In addition, a cationic surfactant satisfying formula (1) may be used in combination with a cationic surfactant not satisfying formula (1). Of the total amount of cationic surfactants, the cationic surfactant satisfying formula (1) is preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably consists of only cationic surfactants satisfying formula (1).

[0038] The cationic surfactant according to this embodiment preferably contains a quaternary ammonium salt having an oxyalkylene group, and more preferably contains a quaternary ammonium salt having a cation represented by formula (2). Here, in formula (2), R ５ and R ６ are each independently a monovalent alkyl group, and R ７ , R ８ , R ９ and R １０ are each independently an alkylene group, and m and n are each independently an integer of 1 or greater. When such a cationic surfactant is used, the artificial hair fiber has excellent antistatic properties and better combability.

[0039] In formula (2), examples of the alkyl group include an ethyl group, a methyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, a neo-pentyl group, an n-hexyl group, a thexyl group, an n-heptyl group, an n-octyl group, an n-ethylhexyl group, an n-nonyl group, an n-decyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

[0040] In formula (2), examples of the alkylene group include an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, and a hexamethylene group.

[0041] In formula (2), m and n each independently represent an integer of 1 or more, preferably 2 to 20.

[0042] As the cationic surfactant according to this embodiment, a cationic surfactant that satisfies formula (2) and a cationic surfactant that does not satisfy formula (2) may be used in combination. However, of the total amount of cationic surfactants, the cationic surfactant that satisfies formula (2) preferably accounts for 50 mass% or more, more preferably 80 mass% or more, and it is particularly preferable that the cationic surfactant consists solely of cationic surfactants that satisfy formula (2).

[0043] In the surface treatment agent according to this embodiment, the content of the cationic surfactant can be 0.1 to 5.0 parts by mass, preferably 0.5 to 3.0 parts by mass, and more preferably 0.5 to 2.0 parts by mass, based on 10 parts by mass of the hydrophilic polyhydric alcohol. The content of the cationic surfactant may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0 parts by mass, based on 10 parts by mass of the hydrophilic polyhydric alcohol, or may be within a range between any two of the values ​​exemplified here. When the content of the cationic surfactant is equal to or greater than the lower limit, the artificial hair fiber has excellent antistatic properties and excellent combability. When the content of the cationic surfactant is equal to or less than the upper limit, the components in the surface treatment agent are highly compatible with each other, the surface treatment agent can be easily applied uniformly, and the artificial hair fiber has a more moist feel.

[0044] 1.2.3 Other Components The surface treatment agent according to this embodiment may contain other components as needed, to the extent that the effects of the present invention are not impaired. Examples of other components include antibacterial components and preservatives.

[0045] In the surface treatment agent according to this embodiment, when the hydrophilic polyhydric alcohol is 10 parts by mass, the oil content is preferably less than 1 part by mass, more preferably less than 0.5 parts by mass, even more preferably less than 0.1 parts by mass, and particularly preferably none (0 parts by mass). Examples of the oil content according to this embodiment include saturated fatty acids such as stearic acid, palmitic acid, myristic acid, lauric acid, capric acid, and unsaturated fatty acids such as oleic acid; glycerides such as monostearate glyceride, monopalmitic acid glyceride, monomyristic acid glyceride, monolauric acid glyceride, monocapric acid glyceride, and their diglycerides and triglycerides; organic acid glycerides such as citric acid monoglyceride, succinic acid monoglyceride, and lactic acid monoglyceride; silicone oil; and mineral oil. When the oil content is below the upper limit, the compatibility of the components in the surface treatment agent is excellent. As a result, the amount of a component (for example, a nonionic surfactant) required to dissolve oil can be reduced.

[0046] In the surface treatment agent according to this embodiment, when the hydrophilic polyhydric alcohol is taken as 10 parts by mass, the content of the nonionic surfactant is preferably less than 2 parts by mass, more preferably less than 1 part by mass, even more preferably less than 0.5 parts by mass, and particularly preferably none (0 parts by mass). Examples of nonionic surfactants according to this embodiment include polyoxyethylene fatty acid esters (e.g., polyethylene glycol monostearate), polyoxyethylene alkyl ethers, polyoxyethylene hydrogenated castor oil ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene block polymers, polyoxyethylene alkylamine ethers, and fatty acid alkanolamides. While nonionic surfactants have excellent emulsifying properties, the surface treatment agent according to this embodiment preferably does not contain oil, so the content of the nonionic surfactant can be set within this range. When the content of the nonionic surfactant is below the upper limit, the softness of the artificial hair fiber is further improved, and the hue is less likely to change even after hot water treatment.

[0047] 2. Manufacturing Method of Artificial Hair Fiber The manufacturing method of the artificial hair fiber according to this embodiment is not particularly limited as long as it can adhere a surface treatment agent to the base fiber. The manufacturing method of the artificial hair fiber according to this embodiment preferably includes a spinning step of spinning a resin or a resin composition containing a resin and an additive to obtain a base fiber, and an adhering step of adhering a surface treatment agent to the obtained base fiber.

[0048] 2.1 Spinning Process 2.1.1 Spinning Step The spinning process according to this embodiment includes at least a spinning step. A known spinning method can be used for the spinning step according to this embodiment. For example, a resin or resin composition can be extruded from a heated cylinder through a nozzle to perform melt spinning. As the extruder, a conventionally known extruder can be used, such as a single-screw extruder, a counter-rotating twin-screw extruder, or a conical twin-screw extruder.

[0049] The melt spinning conditions can be appropriately set depending on the type of resin and resin composition. For example, the cylinder temperature can be set to 150 to 190°C, and the nozzle temperature can be set to 180±15°C. The cross-sectional shape of the nozzle used in this case can be appropriately set depending on the cross-sectional shape of the artificial hair fiber to be produced.

[0050] The undrawn yarn melt-spun from the nozzle is introduced into a heating cylinder (for example, a heating cylinder temperature of 250°C) and instantaneously heat-treated, and can be taken up by a take-up machine installed directly below the nozzle (for example, about 4.5 m). During winding, the take-up speed can be adjusted so that the undrawn yarn has a desired thickness.

[0051] 2.1.2 Drawing Step The spinning process according to this embodiment may further include a drawing step. In the drawing step, the undrawn fiber obtained in the spinning step described above is drawn in a drawing machine to obtain a base fiber. As an example, in the drawing step, the undrawn fiber can be drawn 2 to 5 times in an air atmosphere at 90 to 110°C.

[0052] 2.2 Adhesion Step In the adhesion step according to this embodiment, any adhesion method can be used. For example, the surface treatment agent may be adhered to the base fiber by a roll transfer method, or the base fiber may be immersed in the surface treatment agent. The amount of the surface treatment agent adhered to the base fiber according to this embodiment can be adjusted by adjusting the amount charged or the concentration of each component of the surface treatment agent other than the solvent.

[0053] 2.3 Heat Treatment Step The method for producing artificial hair fibers according to this embodiment may further include a heat treatment step. In the heat treatment step, the base fiber before the surface treatment agent is applied or the artificial hair fiber after the surface treatment agent is applied can be heat-treated using a heat treatment machine. Therefore, the heat treatment step according to this embodiment may be carried out before or after the application step. As an example, in the heat treatment step, the base fiber before the surface treatment agent is applied or the artificial hair fiber after the surface treatment agent is applied is heat-treated in an air atmosphere at 90 to 110°C so that the fiber shrinks by 0.50 to 0.99 times its original size, causing the entire fiber length to thermally shrink, thereby obtaining a fiber with the desired fineness.

[0054] 2.4 Gear Processing Step The method for producing artificial hair fibers according to this embodiment may further include a gear processing step. In this gear processing step, crimping can be achieved by passing the fiber bundle between two meshing, high-temperature gears. The material of the gears used in this gear processing step, the shape of the gear waves, the number of gear teeth, and the like are not particularly limited. In this gear processing step, the shape of the resulting artificial hair fibers can be controlled by appropriately adjusting the depth of the gear wave grooves, the gear surface temperature, the processing speed, and the pressure conditions between the gears, taking into consideration the fiber material and fineness. These processing conditions are not particularly limited, but as an example, the depth of the gear wave grooves (gear pitch) can be 0.2 to 6 mm, preferably 0.5 to 5 mm, the gear surface temperature can be 30 to 100°C, preferably 40 to 80°C, and the processing speed can be 0.5 to 10 m / min, preferably 1.0 to 8.0 m / min.

[0055] In the present invention, "artificial hair fiber" refers to the base fiber after a surface treatment agent has been attached, and includes artificial hair fiber after surface treatment agent attachment, artificial hair fiber after heat treatment, and artificial hair fiber after gear processing.

[0056] 3. Physical Properties of Artificial Hair Fiber 3.1 Fineness of Artificial Hair Fiber The fineness of the base fiber according to this embodiment can be 30 to 60 d (denier), preferably 35 to 55 d, and more preferably 40 to 50 d. The fineness of the base fiber may be, for example, 30, 35, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 55, or 60 d, or may be within a range between any two of the values ​​exemplified here. When the fineness of the base fiber is equal to or greater than the lower limit, the artificial hair fiber is less likely to stretch when combed, resulting in better combability. Furthermore, the contact area between the artificial hair fiber and the comb increases during combing, increasing the coefficient of friction and providing more appropriate slip resistance. When the fineness of the base fiber is equal to or less than the upper limit, the Young's modulus of the artificial hair fiber is reduced, improving softness and providing a more moist feel.

[0057] 3.2 Coefficient of Static Friction The coefficient of static friction of the artificial hair fiber according to this embodiment is preferably 0.30 or more, more preferably 0.35 or more, and even more preferably 0.38 or more. The upper limit of the coefficient of static friction of the artificial hair fiber is, for example, 0.50. The coefficient of static friction of the artificial hair fiber may be, for example, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.45, or 0.50, or may be within a range between any two of the values ​​exemplified here. The static friction coefficient of artificial hair fibers can be, for example, the friction coefficient at the start of sliding when a urethane terminal is moved from a position 100 mm from one end of an artificial hair fiber bundle having a length of 300 mm and a mass of 10 g toward the other end at a speed of 10 mm / sec, a distance of 45 mm, and a load of 200 g. The static friction coefficient of artificial hair fibers can be adjusted by the fineness and cross-sectional shape of the base fiber, as well as the composition and amount of the surface treatment agent applied. When the static friction coefficient of artificial hair fibers is equal to or greater than the lower limit, they will have an appropriate degree of slip resistance.

[0058] 3.3 Dynamic Friction Coefficient The dynamic friction coefficient of the artificial hair fiber according to this embodiment is preferably 0.30 or more, more preferably 0.34 or more, and even more preferably 0.37 or more. The upper limit of the dynamic friction coefficient of the artificial hair fiber is, for example, 0.50. The dynamic friction coefficient of the artificial hair fiber may be, for example, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.45, or 0.50, or may be within a range between any two of the values ​​exemplified here. The dynamic friction coefficient of the artificial hair fiber can be, for example, the friction coefficient after sliding (average friction coefficient during sliding) measured in the same manner as the static friction coefficient described above. The dynamic friction coefficient of the artificial hair fiber can be adjusted by the resin and fineness of the base fiber, as well as the composition and amount of the surface treatment agent applied. The dynamic friction coefficient of the artificial hair fiber can be adjusted by the fineness and cross-sectional shape of the base fiber, and the composition and amount of the surface treatment agent. When the dynamic friction coefficient of the artificial hair fiber is equal to or higher than the lower limit, the artificial hair fiber has an appropriate degree of slipperiness.

[0059] 3.4 μs-μk In the artificial hair fiber according to this embodiment, where μs is the static friction coefficient and μk is the dynamic friction coefficient, the μs-μk value is preferably 0.05 or less, more preferably 0.04 or less, and even more preferably 0.03 or less. The smaller the μs-μk value, the less creaking the artificial hair fiber will be when touched, making it feel smoother, thereby improving softness and ultimately moisturizing the feel.

[0060] 3.5 Surface Resistivity The surface resistance of the artificial hair fiber according to this embodiment is 1×10 １４ Ω / sq. or less, and may be 1×10 １２ Ω / sq. or less, and preferably 1×10 １０ The lower limit of the surface resistance of the artificial hair fiber according to this embodiment is not particularly limited, but is, for example, 1×10 ２ Ω / sq., 1×10 ３ Ω / sq. or 1 x 10 ４The surface resistance of the artificial hair fiber can be expressed as Ω / sq. For example, the surface resistance of an artificial hair fiber bundle having a length of 600 mm and a mass of 20 g is measured at a voltage of 10 V applied to a unit area of ​​1 cm after being left for 24 hours in an environment of 23°C and 50% RH. ２ The smaller the surface resistance value, the better the antistatic property, and therefore the better the combability of the artificial hair fiber.

[0061] 3.6 Young's Modulus The Young's modulus of the artificial hair fiber according to this embodiment may be 3700 MPa or less, preferably 3500 MPa or less, and more preferably 3300 MPa or less. The lower limit of the Young's modulus of the artificial hair fiber according to this embodiment is not particularly limited, but can be, for example, 2000 MPa, 2500 MPa, or 3000 MPa. The Young's modulus of the artificial hair fiber can be calculated, for example, from the slope of the stress versus strain of the fiber in the elastic deformation region per cross-sectional area when a tensile test is performed on the artificial hair fiber (single fiber) at a chuck distance of 200 mm and a tensile speed of 200 mm / min. The smaller the Young's modulus, the softer the artificial hair fiber, and therefore the more moist it will feel.

[0062] 3.7 Slipperiness The artificial hair fiber according to this embodiment preferably has a moderate slipperiness. The slipperiness of the artificial hair fiber can be evaluated by the degree of slipperiness felt by a hair fiber processing technician (with at least 5 years of work experience) when braiding an artificial hair fiber bundle having a length of 600 mm and a mass of 120 g.

[0063] 3.8 Combability The artificial hair fiber according to this embodiment preferably has excellent combability. The combability of the artificial hair fiber can be evaluated, for example, by the degree of ease with which a hair fiber processing technician (with at least 5 years of work experience) feels when combing a bundle of artificial hair fibers having a length of 600 mm and a mass of 120 g.

[0064] 3.9 Moisture The artificial hair fiber according to this embodiment preferably has an excellent moist feel. The moist feel of the artificial hair fiber can be evaluated, for example, by bundling artificial hair fiber bundles each 600 mm long and weighing 120 g, and having 10 hair fiber processing technicians (with at least 5 years of practical experience) evaluate the feel (softness felt when touching the fiber bundle as if compressing it with the palm of their hand). To obtain artificial hair fibers with an excellent moist feel, it is important to improve softness and moisture retention. The softness of the artificial hair fiber can be improved by adjusting the μs-μk, Young's modulus, and bending rigidity to appropriate values. The moisture retention of the artificial hair fiber can be improved by adjusting the composition and application amount of the surface treatment agent to appropriate values.

[0065] 3.10 Change in Hue It is preferable that the artificial hair fiber according to this embodiment is resistant to change in hue even after hot water treatment. The change in hue of the artificial hair fiber can be evaluated by the color difference ΔE, which can be measured, for example, by the following method. (1) A bundle of artificial hair fibers having a length of 300 mm and a mass of 10 g is heat-treated at 120°C for 5 minutes in an air atmosphere, and the color tone of the artificial hair fiber after 120°C heat treatment is measured using a color tone meter. The heat treatment at 120°C for 5 minutes can be a dry process. (2) The artificial hair fiber after 120°C heat treatment is immersed in 90°C water for 30 seconds, and then dried, and the color tone of the artificial hair fiber after 90°C hot water treatment is measured using a color tone meter. (3) The color difference ΔE can be calculated using the following formula. In the formula, the color tone of the artificial hair fiber after 120°C heat treatment is expressed as L ＊ =L １２０ ＊ , a ＊ = a １２０ ＊ , b ＊ = b １２０ ＊ After hot water treatment at 90°C, the color tone of the artificial hair fiber was ＊ =L ９０ ＊ , a ＊ = a ９０ ＊ , b ＊ = b ９０ ＊ Let ΔL ＊=|L ９０ ＊ -L １２０ ＊ | Δa ＊ = | a ９０ ＊ -a １２０ ＊ | Δb ＊ = | b ９０ ＊ -b １２０ ＊ | ΔE = {(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb ＊ ) ２} １／２ In the above measurement method, the step of heat treating the artificial hair fiber at 120°C for 5 minutes is carried out with the intention of resetting the change in color tone that occurs in the hot water treatment step. Although the color tone of artificial hair fiber may change after hot water treatment, by carrying out the step of heat treating at 120°C for 5 minutes, the color tone returns to the same level as before the hot water treatment step. Therefore, according to the above measurement method, even if the artificial hair fiber to be evaluated has already been subjected to hot water treatment, the color tone change is reset before the hot water treatment step is carried out, so that whether the artificial hair fiber to be evaluated has been subjected to hot water treatment or not, it is possible to evaluate the change in color difference that may occur in a single hot water treatment under specific conditions.

[0066] The ΔE value of the artificial hair fiber according to this embodiment is preferably 2.5 or less, more preferably 2.3 or less, and even more preferably 2.0 or less. The smaller the ΔE value, the less likely the artificial hair fiber to change color even after hot water treatment.

[0067] 4. Hair Accessory Products The artificial hair fibers according to this embodiment can be used in hair accessory products. Examples of hair accessory products include wigs, hair pieces, braids, hair extensions, doll hair, hair wigs, false hair, and hair bands. Hair accessory products obtained from a plurality of artificial hair fibers according to this embodiment have suitable non-slip properties and excellent combability, and also have an excellent moist feel. Furthermore, the color of the hair accessory products according to this embodiment is resistant to change even after hot water treatment.

[0068] The hair accessory product according to this embodiment can be applied to various styles, but is particularly suitable for braids, including braids and twists.

[0069] The present invention will be described in more detail below with reference to examples. Note that the examples described below are representative examples of the present invention and should not be construed as narrowing the scope of the present invention.

[0070] <Preparation of Base Fiber> The following resins and resin compositions were prepared as base fibers. Base fibers were obtained by spinning from a nozzle by a melt spinning method so as to have the cross-sectional shapes shown in Tables 1 to 3. (Type of resin) A: Fiber obtained by spinning from a nozzle by a solution spinning method using 70 parts by mass of a vinyl chloride homopolymer (Taiyo Vinyl Corporation "TH-700"), 30 parts by mass of an acrylonitrile-styrene copolymer (Denka Company Limited "GR-AT-6S"), and 0.5 parts by mass of carbon black as raw materials. B: Fiber obtained by spinning from a nozzle by a solution spinning method using 100 parts by mass of a vinyl chloride homopolymer (Taiyo Vinyl Corporation "TH1000") and 0.5 parts by mass of carbon black as raw materials. C: Fiber obtained by spinning from a nozzle by a solution spinning method using 100 parts by mass of an acrylonitrile-styrene copolymer (Denka Company Limited "GR-AT-6S") and 0.5 parts by mass of carbon black as raw materials. D: Fiber obtained by spinning from a nozzle by a solution spinning method using 100 parts by mass of polyethylene terephthalate (Mitsui Chemicals, Inc. "J125S") and 0.5 parts by mass of carbon black as raw materials. E: Fiber obtained by spinning from a nozzle by a solution spinning method using 100 parts by mass of polyamide resin (nylon 66; "Leona (registered trademark) 1500" manufactured by Asahi Kasei Chemicals Corporation) and 0.5 parts by mass of carbon black as raw materials.

[0071] <Preparation of Surface Treatment Agent> Each surface treatment agent was obtained by mixing the components according to the compositions shown in Tables 1 to 3. The components used to obtain the surface treatment agents are as follows. (Hydrophilic polyhydric alcohol) Polyethylene glycol (average degree of polymerization 4): "PEG-200" manufactured by Aoki Yushi Co., Ltd. Polyethylene glycol (average degree of polymerization 30): "PEG-1540" manufactured by Aoki Yushi Co., Ltd. Glycerin: "Concentrated glycerin for cosmetics" manufactured by Sakamoto Pharmaceutical Industry Co., Ltd. Diglycerin: "Diglycerin S" manufactured by Sakamoto Pharmaceutical Industry Co., Ltd. Polyvinyl alcohol: "Denka Poval (registered trademark) PVA B-17" manufactured by Denka Company Limited (degree of polymerization 1700, degree of saponification 87.0 to 89.0 mol%)

[0072] (Cationic surfactants) Quaternary ammonium salt: "F-20" manufactured by Yoshimura Oil Chemical Co., Ltd. (satisfies formula (1) and formula (2)) Lauryl trimethyl ammonium chloride: "Catinal LTC-35A" manufactured by Toho Chemical Industry Co., Ltd. (satisfies formula (1))

[0073] <Preparation of Artificial Hair Fibers> After each synthetic fiber was stretched at 100°C, each surface treatment agent was applied to each synthetic fiber by roll transfer. The roll transfer conditions were a roll radius of 125 mm, the roll was immersed in the aqueous solution of the surface treatment agent up to a height of 20 mm from the bottom end of the roll, and the roll rotation speed was 0.2 to 8 m / min. A heat treatment step was then carried out at 110°C, and heat-treated artificial hair fibers with the finenesses shown in Tables 1 to 3 were obtained.

[0074] Using a gear machine ("NEW YAKI BRAID CRIMPING M / C-2.5mm" manufactured by SUNG JIN INDUSTRIAL CO., LTD.), gear processing was performed on the artificial hair fiber after each heat treatment under the conditions of a gear pitch of 2.5 mm, preheating at 90°C, a gear roll temperature of 90°C, and a gear roll rotation speed of 1 m / min, to obtain a gear-processed artificial hair fiber.

[0075] The artificial hair fibers thus produced were subjected to the tests and evaluations described below, and the results are shown in Tables 1 to 3.

[0076]

[0077]

[0078]

[0079] (Static friction coefficient) For an evaluation artificial hair fiber bundle having a length of 300 mm and a mass of 10 g, a urethane terminal (tactile contact, finger model, manufactured by TRINITY-LAB) was moved from a position 100 mm from one end toward the other end at a moving speed of 10 mm / sec, a moving distance of 45 mm, and a load of 200 g, and the friction coefficient at the start of sliding was measured using a static and dynamic friction measuring device ("TL201Tt" manufactured by TRINITY-LAB). Five measurements were taken at different positions on each evaluation artificial hair fiber bundle, and the average value was used as the static friction coefficient of each artificial hair fiber.

[0080] (Dynamic Friction Coefficient) The average value of the friction coefficients after sliding when the above-mentioned measurements were carried out was taken as the dynamic friction coefficient of each artificial hair fiber.

[0081] (μs−μk) The value of μs−μk was calculated, where μs is the static friction coefficient obtained by the above measurement, and μk is the dynamic friction coefficient.

[0082] (Surface resistance value) For an artificial hair fiber bundle for evaluation having a length of 600 mm and a mass of 20 g, the surface resistance value was measured by applying a voltage of 10 V to a unit area of ​​1 cm after leaving the fiber bundle for evaluation in an environment of 23°C and 50% RH for 24 hours. ２ The surface resistance value per unit area was measured using a digital ultra-high resistance / microcurrent meter ("R8340A" by ADVANTEST Co., Ltd.) and the average value of five measurements was calculated.

[0083] (Young's Modulus) A tensile test was carried out on each artificial hair fiber using a tensile tester (Shimadzu Corporation, "Autograph AGS-X") with a chuck distance of 200 mm and a tensile speed of 200 mm / min. Young's modulus was calculated from the slope of stress versus strain of the fiber in the elastic deformation region per cross-sectional area. The average value of 10 measurements was calculated.

[0084] (Slipperiness) Ten hair fiber processing technicians (with at least 5 years of work experience) braided an evaluation artificial hair fiber bundle having a length of 600 mm and a mass of 120 g, and evaluated the degree of slipperiness of the fiber as perceived by them as either "not slippery" or "slippery" according to the following criteria: 4: 10 people rated it as slippery 3: 6 to 9 people rated it as slippery 2: 2 to 5 people rated it as slippery 1: 1 person or less rated it as slippery

[0085] (Combability) Ten hair fiber processing technicians (with at least 5 years of work experience) combed an artificial hair fiber bundle for evaluation, 600 mm in length and 120 g in mass, through their fingers. The technicians rated the ease of combing the fiber bundle using a hand comb, using two ranks: "easy to comb" or "difficult to comb", and evaluated it according to the following criteria: 4: 10 technicians rated it as not slippery 3: 6 to 9 technicians rated it as not slippery 2: 2 to 5 technicians rated it as not slippery 1: 1 technician or less rated it as not slippery

[0086] (Moisturizing Feeling) Artificial hair fiber bundles of 600 mm in length and 120 g in mass were bundled together, and ten hair fiber processing technicians (with at least five years of work experience) judged the feel (softness felt when touching the fiber bundle as if compressing it with the palm) into two ranks of "moist" or "dry" and evaluated according to the following criteria: 4: 10 or more technicians rated it as moist; 3: 6 to 9 technicians rated it as moist; 2: 2 to 5 technicians rated it as moist; 1: 1 technician or less rated it as moist.

[0087] (Color difference ΔE) The color difference ΔE before and after hot water treatment was calculated using the following procedure. (1) A 300 mm long, 10 g mass artificial hair fiber bundle was heat-treated at 120°C for 5 minutes in an air atmosphere, and the color tone of the artificial hair fiber after 120°C heat treatment was measured using a color tone meter. The 120°C, 5 minute heat treatment was considered a dry process. (2) The artificial hair fiber after 120°C heat treatment was immersed in 90°C water for 30 seconds, and then dried, and the color tone of the artificial hair fiber after 90°C hot water treatment was measured using a color tone meter. (3) The color difference ΔE was calculated using the following formula. In the formula, the color tone of the artificial hair fiber after 120°C heat treatment is expressed as L ＊ =L １２０＊ , a ＊ = a １２０ ＊ , b ＊ = b １２０ ＊ After hot water treatment at 90°C, the color tone of the artificial hair fiber was ＊ =L ９０ ＊ , a ＊ = a ９０ ＊ , b ＊ = b ９０ ＊ Let ΔL ＊ =|L ９０ ＊ -L １２０ ＊ | Δa ＊ = | a ９０ ＊ -a １２０ ＊ | Δb ＊ = | b ９０ ＊ -b １２０ ＊ | ΔE = {(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb ＊ ) ２} １／２

[0088] The results in Tables 1 to 3 show that the artificial hair fiber according to the present invention had both moderate slipperiness and combability, and also had an excellent moist feel. Furthermore, even after hot water treatment, the color difference ΔE was small and the hue was unlikely to change.

Claims

1. An artificial hair fiber comprising a base fiber and a surface treatment agent attached to at least a portion of the surface of the base fiber, wherein the surface treatment agent contains a hydrophilic polyhydric alcohol and a cationic surfactant, and the total amount of the attached hydrophilic polyhydric alcohol and the cationic surfactant is 0.03 to 0.30% by mass when the artificial hair fiber is taken as 100% by mass.

2. The artificial hair fiber according to claim 1, wherein the content of the cationic surfactant in the surface treatment agent is 0.5 to 3.0 parts by mass per 10 parts by mass of the hydrophilic polyhydric alcohol.

3. The cationic surfactant contains a quaternary ammonium salt having a cation represented by the following formula (1): In formula (1), R １ , R ２ , R ３ and R ４ The artificial hair fiber according to claim 1 or 2, wherein each of the groups independently represents a monovalent organic group.

4. The artificial hair fiber according to claim 1 or 2, wherein the fineness of the artificial hair fiber is 40 to 50 d, and the Young's modulus of the artificial hair fiber is 3500 MPa or less.

5. The artificial hair fiber according to claim 1 or 2, wherein the base fiber comprises at least one material selected from the group consisting of vinyl chloride homopolymer, vinyl chloride-acrylonitrile copolymer, polyethylene terephthalate, polyamide resin, polypropylene, and acrylonitrile-styrene copolymer.

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