Fiber for artificial hair and hair ornament

Abstract

To provide a fiber for artificial hair which is excellent in ease of knitting.SOLUTION: There is provided a fiber for artificial hair excellent in ease of knitting, in which the fiber for artificial hair has a delay time δ of 0.0138-0.0200 calculated from a friction profile measured by a sinusoidal motional friction evaluation device. The measuring method comprises: making a yarn bundle of 10 g using the fiber for artificial hair cut to 30 cm; and measuring a surface friction resistance force of the fiber bundle for the testing artificial hair by causing a contact to perform a sinusoidal motion in the linear direction under conditions of a travel distance of 30 mm, a vertical load of 0.98 N, a rotation speed of 2.1 rad / s, and a maximum speed of 30 mm / s using a sinusoidal motional friction evaluation device to obtain the friction profile, and calculating the delay time δ represented by the following expression (1) from the frictional profile: δ=Δt / T0 ...(1), where Δt represents a time required from a time point at which the speed of the contact becomes 0 to a time point at which the friction force becomes 0 for the first time, and T0 represents a time required for one reciprocation of the sinusoidal motion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to fibers for artificial hair and hair decoration products. [Background technology]

[0002] Artificial hair is becoming increasingly important as an alternative to human hair in head accessories such as wigs, hairpieces, hair extensions, hair bands, doll hair, etc. Materials used to make 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 states that the bending rigidity according to the KES method is 0.7 to 2.5 gf cm 2 In a fiber bundle obtained by crimping a fiber (A) having a crimp wave shape that satisfies the following formula: 1mm≦R≦20mm (where R is the length of the crimp wave peaks and valleys.) The fiber bundle for artificial hair is disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-47846 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional techniques, it has been difficult to obtain fibers for artificial hair that are easy to weave.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a fiber for artificial hair that is easy to weave. [Means for solving the problem]

[0007] According to the present invention, there is provided an artificial hair fiber, wherein a 10 g yarn bundle is made from the artificial hair fiber cut to a length of 30 cm to obtain a test artificial hair fiber bundle, and a sinusoidal motion friction evaluation device is used to perform sinusoidal motion of a contactor in a linear direction under conditions of a movement distance of 30 mm, a normal load of 0.98 N, a rotation speed of 2.1 rad / s, and a maximum speed of 30 mm / s, thereby measuring the surface friction resistance of the test artificial hair fiber bundle and obtaining a friction profile, wherein the delay time δ calculated from the friction profile is 0.0138 to 0.0200, and the delay time δ is expressed by the following formula (1): δ=Δt / T0 (1) (In equation (1), Δt represents the time required from the point at which the speed of the contactor becomes 0 to the point at which the frictional force first becomes 0, and T0 represents the time required for one reciprocation of the sinusoidal motion.)

[0008] The present inventors have conducted extensive research and have found that by controlling the delay time δ calculated from the friction profile measured by a sinusoidal motion friction evaluation device within a specific numerical range, artificial hair fibers that are easy to weave can be obtained, leading to the completion of the present invention.

[0009] Various embodiments of the present invention will be described below as examples, and the embodiments shown below can be combined with each other. [1] An artificial hair fiber, wherein a 10 g yarn bundle is made from the artificial hair fiber cut to a length of 30 cm to obtain a test artificial hair fiber bundle, and a sinusoidal motion friction evaluation device is used to perform sinusoidal motion of a contactor in a linear direction under conditions of a moving distance of 30 mm, a normal load of 0.98 N, a rotation speed of 2.1 rad / s, and a maximum speed of 30 mm / s, thereby measuring the surface friction resistance of the test artificial hair fiber bundle and obtaining a friction profile. The delay time δ calculated from the friction profile is 0.0138 to 0.0200, and the delay time δ is expressed by the following formula (1): δ=Δt / T0 (1) (In formula (1), Δt is the time required from the point at which the speed of the contactor becomes 0 to the point at which the friction force first becomes 0, and T0 is the time required for one reciprocal movement of the sinusoidal motion.) [2] The artificial hair fiber according to [1], wherein the dynamic friction coefficient μk obtained by measuring the surface friction resistance of the test artificial hair fiber bundle is 0.150 to 0.600. [3] The compression energy WC of the test artificial hair fiber bundle is 28.0 to 40.0 gf cm / cm 2 The artificial hair fiber according to [1] or [2], [4] The artificial hair fiber according to any one of [1] to [3], wherein the specific volume of the test artificial hair fiber bundle is 5.0 cc / g or more and 25.0 cc / g or less. [5] The artificial hair fiber according to any one of [1] to [4], which contains a polyvinyl chloride resin. [6] A hair accessory comprising the artificial hair fiber according to any one of [1] to [5]. [Effects of the Invention]

[0010] The artificial hair fiber according to the present invention is easy to weave, and hair accessories comprising the artificial hair fiber according to the present invention are easy to weave. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below by illustrating embodiments of the present invention. The present invention is not limited by these descriptions. The features of the embodiments of the present invention described below can be combined with each other. Furthermore, each feature can be an invention independently.

[0012] 1. Artificial hair fibers In the present invention, fiber for artificial hair means fiber used for artificial hair such as wigs, hair toupees, and hairpieces that can be attached to and detached from the head. An example of a method for producing the fiber for artificial hair of the present invention will be described later, but the fiber for artificial hair according to one embodiment of the present invention includes fiber for artificial hair after spinning, and encompasses fiber for artificial hair before the drawing step, after the drawing step, before the heat treatment step, after the heat treatment step, before the shaping step, after the shaping step, before the surface treatment agent application step, and after the surface treatment agent application step. The fiber for artificial hair according to one embodiment of the present invention is preferably fiber for artificial hair after the shaping step.

[0013] 1.1 Characteristics of artificial hair fibers The artificial hair fiber according to the present invention is prepared by cutting the artificial hair fiber to a length of 30 cm and creating a 10 g yarn bundle to obtain a test artificial hair fiber bundle. Using a sinusoidal motion friction evaluation device, the contactor is sinusoidally moved in a linear direction under the conditions of a moving distance of 30 mm, a normal load of 0.98 N, a rotational speed of 2.1 rad / s, and a maximum speed of 30 mm / s, thereby measuring the surface friction resistance of the test artificial hair fiber bundle and obtaining a friction profile, wherein the delay time δ calculated from the friction profile is 0.0138 to 0.0200. Here, the delay time δ is expressed by the following equation (1). δ=Δt / T0 (1) In equation (1), Δt represents the time required from the point at which the speed of the contactor becomes 0 until the frictional force first becomes 0, and T0 represents the time required for one reciprocation of the sinusoidal motion.

[0014] Conventionally, the ease of weaving artificial hair fibers has been an extremely important evaluation factor for hairdressers and consumers who handle artificial hair fibers, but it has been difficult to control such sensory characteristics. As a result of extensive research, the present inventors have found that the ease of weaving can be controlled by controlling the delay time δ, calculated from the friction profile obtained when measuring the surface friction resistance of a test artificial hair fiber bundle made of artificial hair fiber, within a certain numerical range.

[0015] The delay time δ is a parameter calculated from the friction profile obtained by using a sinusoidal motion friction evaluation device to move the contactor sinusoidally in a linear direction on a test artificial hair fiber bundle. When the contactor is moved back and forth, depending on the sample, the friction coefficient changes sign slightly after the point at which the velocity changes sign (the point at which it becomes 0). The delay time δ is a parameter related to this delay, and specifically indicates the value obtained by dividing the time difference (Δt) in the response of the friction force to the movement of the contactor by the friction time (T0) required for one round trip. The sinusoidal motion friction evaluation device moves the contactor sinusoidally in a linear direction on the material to be evaluated to obtain a friction profile, and the device described in the following document can be used. Sano M, Mayama H, Nonomura Y, Friction dynamics of human hair treated with water or cationic surfactant aqueous solution. J Surfact Deterg. 2023;26(2):185-93. https: / / doi.org / 10.1002 / jsde.12634

[0016] Although the mechanism by which these evaluation items can be simultaneously controlled by controlling the delay time δ is unclear, lag time is generally more likely to occur in materials that are easily deformed or sink, and it is thought that for samples with similar shapes, the degree of lag time is determined by a complex interaction of other factors such as rigidity, friction on the fiber surface, friction between fibers, yarn bundle thickness, specific volume, etc., and that it varies depending on material characteristics such as ease of deformability and ease of sinking, as well as factors such as rigidity, friction on the fiber surface, friction between fibers, yarn bundle thickness, and specific volume. It is presumed that this parameter, delay time δ, functions as a comprehensive index of these factors, and that by controlling the delay time δ within a specific numerical range, it becomes possible to control the ease of knitting during knitting.

[0017] The delay time δ is, for example, 0.0138, 0.0140, 0.0145, 0.0150, 0.0155, 0.0160, 0.0165, 0.0170, 0.0175, 0.0180, 0.0185, 0.0190, 0.0195, 0.0200, and may be within a range between any two of the values exemplified here.

[0018] The delay time δ can be measured specifically by the method described in the Examples. The delay time δ can be controlled by adjusting the manufacturing conditions of the artificial hair fiber, for example, by changing the types and compounding ratios of the resins constituting the artificial hair fiber, the fineness of the raw yarn, conditions in the drawing and heat treatment steps such as the draw ratio, conditions in the surface treatment agent application step such as the type of surface treatment agent, and conditions in the shaping step such as the gear preheating temperature.

[0019] In the artificial hair fiber according to one embodiment of the present invention, the dynamic friction coefficient μk obtained by measuring the surface friction resistance of a test artificial hair fiber bundle can be 0.150 to 0.600, and preferably 0.270 to 0.600. The coefficient of dynamic friction μk is, for example, 0.150, 0.200, 0.250, 0.270, 0.300, 0.350, 0.400, 0.450, 0.500, 0.550, or 0.600, and may be within a range between any two of the numerical values exemplified here. When the dynamic friction coefficient μk is within the above-mentioned range, it becomes easier to adjust the delay time δ within the above-mentioned range, and the artificial hair fiber is excellent in ease of weaving and in slipperiness during weaving.

[0020] The dynamic friction coefficient μk can be the average value of the friction coefficient that occurs after the static friction coefficient μs is observed until the speed becomes 0. Here, the static friction coefficient μs can be the maximum value of the friction coefficient after the start of friction and before the friction starts to decrease. Specifically, the dynamic friction coefficient μk can be determined by the method described in the examples. The dynamic friction coefficient μk can be controlled by adjusting the manufacturing conditions of the artificial hair fiber, for example, by changing the type and compounding ratio of the resins constituting the artificial hair fiber, the fineness of the raw yarn, conditions of the drawing process and heat treatment process such as the draw ratio, conditions of the surface treatment agent application process such as the type of surface treatment agent, and conditions of the shaping process such as the gear preheating temperature.

[0021] The artificial hair fiber according to one embodiment of the present invention has a compression energy WC of 28.0 to 40.0 gf cm / cm 2 and the strength is 29.0-40.0gf·cm / cm 2 The compression energy WC is preferably, for example, 28.0, 29.0, 30.0, 32.0, 34.0, 36.0, 38.0, or 40.0 gf cm / cm 2 and may be in a range between any two of the values given here. When the compression energy WC is within the above range, it becomes easier to adjust the delay time δ within the above range. Furthermore, when the compression energy WC is within the above range, the artificial hair fiber is easy to weave, has excellent volume, and is particularly excellent in elasticity.

[0022] The compression energy WC can be measured using a compression tester, specifically, for example, the device described in the Examples. The compression energy WC can be controlled by adjusting the manufacturing conditions of the artificial hair fiber. For example, it can be adjusted by changing the types and compounding ratios of the resins constituting the artificial hair fiber, the fineness of the raw yarn, conditions of the drawing process and heat treatment process such as the draw ratio, conditions of the surface treatment agent application process such as the type of surface treatment agent, and conditions of the shaping process such as the gear preheating temperature.

[0023] The specific volume of the artificial hair fiber according to one embodiment of the present invention can be 5.0 to 25.0 cc / g, and is preferably 7.5 cc / g or more and less than 21.0 cc / g. The specific volume may be, for example, 5.0, 6.0, 6.5, 7.5, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, 20.5, 21.0, 22.0, 23.0, 24.0, or 25.0 cc / g, or may be within a range between any two of the values exemplified here. When the specific volume is within the above range, it becomes easier to adjust the delay time δ within the above range, and the artificial hair fiber is excellent in ease of weaving and elasticity, particularly volume.

[0024] The specific volume can be adjusted by the method described in the Examples. The specific volume can be controlled by adjusting the manufacturing conditions of the artificial hair fiber, for example, by changing the type and compounding ratio of the resins constituting the artificial hair fiber, the fineness of the raw yarn, conditions of the drawing process and heat treatment process such as the draw ratio, conditions of the surface treatment agent application process such as the type of surface treatment agent, and conditions of the shaping process such as the gear preheating temperature.

[0025] 1.2 Resin composition of artificial hair fibers The resin composition constituting the artificial hair fiber according to one embodiment of the present invention is not particularly limited, and may include at least one of polyamide resin, polyester resin, vinyl chloride resin, cross-linked vinyl chloride resin, AS resin (acrylonitrile styrene resin), PP resin, PET resin, PE resin, PAN resin, PLA resin (polylactic acid resin), and polyacrylonitrile resin (acrylic, modacrylic, etc.). The artificial hair fiber according to one embodiment of the present invention preferably includes one selected from vinyl chloride resin, AS resin, cross-linked vinyl chloride resin, and polyacrylonitrile resin (acrylic, modacrylic, etc.).

[0026] The artificial hair fiber according to one embodiment of the present invention preferably contains a vinyl chloride resin. The artificial hair fiber according to one embodiment of the present invention may contain, for example, 50, 60, 70, 80, 90, or 100% by mass of the vinyl chloride resin relative to 100% by mass of the artificial hair fiber. The polyvinyl chloride resin according to one embodiment of the present invention may contain a vinyl chloride polymer containing a monomer unit (vinyl chloride monomer unit) derived from a vinyl chloride monomer. Note that, in this specification, the vinyl chloride resin may refer to a non-crosslinked vinyl chloride resin and may not include a crosslinked vinyl chloride resin. The polyvinyl chloride resin according to the present invention may include a homopolymer obtained by homopolymerizing a vinyl chloride monomer and / or a copolymer containing a monomer unit derived from a vinyl chloride monomer and another monomer copolymerizable with the vinyl chloride monomer. Examples of 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 olefins, such as vinyl chloride-ethylene copolymer and vinyl chloride-propylene copolymer, and vinyl chloride-acrylonitrile copolymer. The polyvinyl chloride resin according to the present invention may consist of one type of vinyl chloride polymer, or may contain two or more types of vinyl chloride polymers.

[0027] An artificial hair fiber according to one embodiment of the present invention preferably contains a vinyl chloride resin and an AS resin (acrylonitrile-styrene-based resin). The AS resin (acrylonitrile-styrene-based resin) is a copolymer containing styrene-based monomer units and acrylonitrile-based monomer units, and may contain other monomer units copolymerizable with these units as necessary. The AS resin may contain, for example, 60, 65, 70, 75, 80, 85, or 90% by mass of styrene-based monomer units relative to 100% by mass of the AS resin, or may fall within a range between any two of the values exemplified here. The AS resin may contain, for example, 10, 15, 20, 25, 30, 35, or 40% by mass of acrylonitrile-based monomer units relative to 100% by mass of the AS resin, or may fall within a range between any two of the values exemplified here.

[0028] The artificial hair fiber according to one embodiment of the present invention preferably contains 5 to 50 parts by mass of AS resin relative to 100 parts by mass of vinyl chloride resin. The content of AS resin relative to 100 parts by mass of vinyl chloride resin is, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 parts by mass, and may be within a range between any two of the values exemplified here.

[0029] The fiber for artificial hair according to one embodiment of the present invention may contain a vinyl chloride resin and a cross-linked vinyl chloride resin. The fiber for artificial hair according to one embodiment of the present invention preferably contains 1 to 10 parts by mass of cross-linked vinyl chloride resin per 100 parts by mass of vinyl chloride resin. The content of cross-linked vinyl chloride resin per 100 parts by mass of vinyl chloride resin is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 parts by mass, and may be within a range between any two of the numerical values exemplified here.

[0030] The artificial hair fiber according to one embodiment of the present invention may contain other ingredients as needed, such as antistatic agents, heat stabilizers, lubricants, colorants, processing aids, plasticizers, strengthening agents, UV absorbers, antioxidants, fillers, flame retardants, pigments, initial color improvers, conductivity imparting agents, and fragrances.

[0031] An artificial hair fiber according to one embodiment of the present invention may contain a vinyl chloride resin, an AS resin, and a cross-linked vinyl chloride resin. Furthermore, by changing the type and amount of each resin, the delay time δ, the dynamic friction coefficient μk, and the compression energy WC can be adjusted. For example, if the specific gravity of the resulting artificial hair fiber is changed by changing the type and amount of each resin in the resin composition constituting the artificial hair fiber, the volume and elasticity of the artificial hair fiber bundle will change, which is presumably changing the delay time δ, the dynamic friction coefficient μk, and the compression energy WC. For example, if the elasticity is increased by using a resin with a high molecular weight, the shape of the fiber bundle will more easily follow the movement of the friction element when the frictional motion changes, which is presumably shortening the delay time δ. Furthermore, for example, if the type and amount of each resin in the resin composition constituting the artificial hair fiber changes, the glass transition temperature of the resin composition constituting the artificial hair fiber will change, which is presumably changing the shapeability in the shaping process, which in turn changes the volume and elasticity, as well as the delay time δ, the dynamic friction coefficient μk, and the compression energy WC. Similarly, if the type and amount of each resin in the resin composition that constitutes the artificial hair fiber is changed and the rigidity of the resulting artificial hair fiber changes, it is presumed that the volume, elasticity, and even the delay time δ, the dynamic friction coefficient μk, and the compression energy WC will change.

[0032] 1.3 Shape The cross-sectional shape of the fiber for artificial hair according to one embodiment of the present invention may be either a round cross-section or an irregular cross-section. The irregular cross-section is not particularly limited, but examples include a flat cross-section, a flower cross-section, a Y-shaped cross-section, a W-shaped cross-section, an H-shaped cross-section, a dumbbell cross-section, a crown cross-section, a doughnut cross-section, and a hollow cross-section. It is preferable that the fiber for artificial hair according to one embodiment of the present invention has at least one of a flat cross-section such as a glasses-shaped cross-section and a round cross-section.

[0033] The artificial hair fiber according to one embodiment of the present invention has an average major axis in a cross section perpendicular to the longitudinal direction of the artificial hair fiber of 30 to 300 μm, preferably 50 to 200 μm. The average major axis may be, for example, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, or 300 μm, or may be within a range between any two of the values exemplified here.

[0034] 1.4 Surface treatment agents The artificial hair fiber according to one embodiment of the present invention preferably has a surface treatment agent on its surface. Examples of the surface treatment agent include polyalkylene glycol-based, long-chain cation-based, silicone-based, and oil-based agents.

[0035] Examples of polyalkylene glycol surface treatment agents include polyethylene glycol, polypropylene glycol, and polyethylene glycol-polypropylene glycol copolymers. Examples of long-chain cationic surface treatment agents include quaternary ammonium salts, guanidine compounds, imidazoline compounds, and pyridinium compounds. Examples of silicone surface treatment agents include modified silicone oils such as amino-modified silicones. Examples of oil-based surface treatment agents include fatty acid skeleton-containing compounds such as fatty acids, fatty acid esters, fatty acid ethers, fatty acid glycerides (including vegetable oils), and organic acid glycerides, as well as mineral oils and higher alcohols.

[0036] The artificial hair fiber according to one embodiment of the present invention may contain 0.01 to 3.00% by mass of a surface treatment agent relative to 100% by mass of the artificial hair fiber. The amount of the surface treatment agent relative to 100% by mass of the artificial hair fiber is, for example, 0.01, 0.03, 0.05, 0.10, 0.30, 0.50, 1.00, 1.50, 2.00, 2.50, or 3.00% by mass, and may be within a range between any two of the values exemplified here.

[0037] By changing the type and amount of the surface treatment agent, it is possible to adjust the delay time δ, the dynamic friction coefficient μk, etc. For example, it is thought that the delay time δ and the dynamic friction coefficient μk can be adjusted by changing the hydrophilicity (hydrophobicity) of the surface treatment agent used, and as an example, it is presumed that the dynamic friction coefficient μk tends to increase when a highly hydrophilic surface treatment agent is used.

[0038] 2. Manufacturing method for artificial hair fibers The method for producing the artificial hair fiber of the present invention is not particularly limited as long as the delay time δ of the artificial hair fiber falls within the above range by adjusting the various production conditions. The method for producing artificial hair fibers according to one embodiment of the present invention may include a step of preparing a resin composition for artificial hair fibers, a spinning step, a drawing step, a heat treatment step, a shaping step, and a surface treatment agent application step.

[0039] 2.1 Preparation process of resin composition for artificial hair fibers In the artificial hair fiber resin composition preparation process, raw materials containing resins are mixed to obtain a resin composition for artificial hair fibers. Here, the raw materials include a base resin and may contain other components as needed. It is preferable to adjust the type and amount of resin contained in the resulting artificial hair fiber resin composition as described in the "Resin Composition of Artificial Hair Fiber" section. As mentioned above, by changing the type and amount of each resin, the delay time δ, the dynamic friction coefficient μk, and the compression energy WC can be adjusted.

[0040] The mixing method is not particularly limited, and conventionally known methods can be employed. For example, a powdered resin composition (powder compound) can be obtained using a known mixing device such as a Henschel mixer, super mixer, or ribbon blender, and the powder compound can then be melt-mixed to obtain a pellet-shaped resin composition (pellet compound). The powder compound can be produced by either hot blending or cold blending. For example, to reduce volatiles from the resin composition, hot blending can be performed at a cut temperature of 105 to 155°C during mixing. The pellet compound can be produced by a method similar to that used to produce pellet compounds of general vinyl chloride resins. For example, pellet compounds can be produced using kneaders such as a single-screw extruder, counter-rotating twin-screw extruder, conical twin-screw extruder, co-rotating twin-screw extruder, co-kneader, planetary gear extruder, or roll kneader. The conditions for producing the pellet compound are not particularly limited, but it is preferable to set the resin temperature to 185°C or less to prevent thermal degradation of the resin composition. A mesh can also be installed near the tip of the screw to remove small amounts of metal chips from the screw and fibers from protective gloves that may be mixed into the pellet compound. The cold-cut method can be used to manufacture pellets. A means of removing chips (fine particles generated during pellet production) that may be mixed in during cold cutting can also be used. Furthermore, since the cutter blades can chip over long periods of use, making chips more likely to be generated, it is recommended that they be replaced as needed.

[0041] 2.2 Spinning process In the spinning step, the resin composition for artificial hair fibers is melt-spun to obtain artificial hair fibers. As an example, the resin composition (e.g., pellet compound) can be extruded from a heated cylinder through a nozzle and melt-spun. Any conventionally known extruder can be used, such as a single-screw extruder, a counter-rotating twin-screw extruder, or a conical twin-screw extruder. A nozzle with an appropriate shape can be selected depending on the cross-sectional shape of the desired artificial hair fiber.

[0042] The melt spinning conditions can be appropriately set depending on the type of resin composition. For example, the cylinder temperature can be set to 140 to 180°C, and the nozzle temperature can be set to 180±15°C.

[0043] The undrawn yarn melt-spun from the nozzle is introduced into a heating cylinder (for example, heating cylinder temperature 250°C) and instantaneously heat-treated, and then wound up on a take-up machine installed directly below the nozzle (for example, about 4.5 m away) to obtain an undrawn yarn.

[0044] 2.3 Stretching process In the drawing step, the undrawn artificial hair fiber obtained in the spinning step is drawn in a drawing machine to obtain drawn artificial hair fiber. For example, in the drawing step, the undrawn artificial hair fiber can be drawn 2.00 to 5.00 times at 90 to 110°C in an air atmosphere. The lag time δ of the resulting artificial hair fiber can be adjusted by changing the temperature and draw ratio in the drawing step. For example, the draw ratio can be 3.00 times or less. The draw ratio can be, for example, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, or 3.00 times, or it can be within a range between any two of the values exemplified here.

[0045] 2.4 Heat treatment process In the heat treatment step, the stretched artificial hair fiber can be heat-treated using a heat treatment machine. For example, in the heat treatment step, the stretched artificial hair fiber can be annealed in an air atmosphere at 90 to 110°C so that the relaxation rate is 20 to 30%. The relaxation rate during annealing is calculated by dividing the rotational speed of the take-up roller during annealing by the rotational speed of the delivery roller during annealing. After the drawing and heat treatment steps, heat-treated artificial hair fiber having a fineness of, for example, 30 to 70 denier can be obtained. The fineness can be adjusted by adjusting the conditions of the spinning, drawing, and heat treatment steps, and can be, for example, 30, 35, 40, 45, 50, 55, 60, 65, or 70 denier, or it can be within a range between any two of the values exemplified here. By changing the temperature and relaxation rate in the heat treatment step and adjusting the fineness, the delay time δ of the resulting artificial hair fiber can be adjusted.

[0046] 2.5 Shaping process In the shaping process, crimping can be achieved by passing the fiber bundle between two meshing high-temperature gears. The material of the gears used, the shape of the gear waves, and the number of gears are not particularly limited. In the shaping process, taking into account the fiber material and fineness, the gear width, the depth of the gear wave grooves, the preheating temperature (the temperature used to preheat the fiber before shaping with the gear roll), the surface temperature and speed of the gear roll, and the pressure conditions between the gear rolls (e.g., adjusting the height of the gear roll pressure adjustment screw to adjust the clamping pressure between the gear rolls) can be appropriately adjusted to adjust the shape of the resulting artificial hair fiber, as well as the specific volume and delay time δ. For example, adjusting these conditions can change the fineness, volume, and gear wave pattern of the processed fiber, which in turn changes the contact area between the friction element and the yarn during friction measurement (ease of the yarn bundle shape to follow the friction element movement), the amount of wrinkling of the yarn bundle during sweeping, and the repulsion from the yarn bundle during the reciprocating motion, which is presumably responsible for the delay time δ, the kinetic friction coefficient μk, and the compression energy WC.

[0047] The gear width can be 1.0 to 10.0 mm, and is preferably 2.0 to 5.0 mm. The gear width can be, for example, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 mm, or can be within a range between any two of the values exemplified here. When shaping is performed at the above gear widths, the resulting artificial hair fiber will have a wavelength (the distance between peaks) corresponding to the above gear width. Specifically, the artificial hair fiber according to the present invention can have an average wavelength (the average distance between peaks) of 1.0 to 12.0 mm, for example, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, or 12.0 mm, or can be within a range between any two of the values exemplified here. The preheating temperature can be 40 to 140°C, for example, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140°C, and may be within a range between any two of the values exemplified here. The surface temperature of the gear roll can be set to 60 to 120°C, for example, 60, 70, 80, 90, 100, 110, or 120°C, and may be within a range between any two of the values exemplified here. The processing speed can be 0.3 to 10 m / min, for example, 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0 m / min, and may be within a range between any two of the numerical values exemplified here. The height of the gear roll pressure adjusting screw can be 0.5 to 3.0 mm, for example, 0.5, 1.0, 1.5, 2.0, 2.5, or 3.0 mm, and may be within a range between any two of the numerical values exemplified here.

[0048] 2.6 Surface treatment agent application process The method for producing fibers for artificial hair according to one embodiment of the present invention may include, at any stage after the spinning step, a surface treatment agent attachment step of attaching a surface treatment agent to the fibers obtained in the previous step. This step allows the above-described surface treatment agent to be attached to the surface of the fiber. The type and amount of the attached surface treatment agent are as described above, and as described above, by changing the type and amount of the surface treatment agent, the delay time δ, the dynamic friction coefficient μk, etc. can be adjusted.

[0049] The method for applying the surface treatment agent is not particularly limited, and known methods can be used, such as applying the surface treatment agent to the artificial hair fiber using a roll to which the surface treatment agent is attached (roll transfer method), immersing the artificial hair fiber in a bath containing the surface treatment agent, or applying the surface treatment agent to the artificial hair fiber using an application tool such as a brush or paintbrush.

[0050] 3. Hair accessories The artificial hair fiber according to one embodiment of the present invention can be suitably used for hair accessories such as wigs, hair pieces, braids, hair extensions, doll hair, hair wigs, false hair, and hair bands. A hair accessory according to one embodiment of the present invention comprises artificial hair fiber. The artificial hair fiber and hair accessory according to one embodiment of the present invention is easy to weave, and is particularly suitable for braids that include braiding, twists, etc. Furthermore, the artificial hair fiber and hair accessory according to one embodiment of the present invention is easy to weave, and also has excellent slip resistance when braiding, volume to the touch, and / or elasticity, i.e., excellent evaluation items that are very important to hairdressers and consumers who handle artificial hair fibers but are difficult to control, and is particularly suitable for braids that include braiding, twists, etc. [Example]

[0051] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited to these examples.

[0052] Example 1 <Step of preparing resin composition for artificial hair fiber> 100 parts by mass of a vinyl chloride resin (manufactured by Taiyo Vinyl Corporation, product name: TH1000), 30 parts by mass of a vinyl copolymer resin (manufactured by Denka Company, Ltd., GR-AT-6S) containing 68% by mass of styrene monomer units and 32% by mass of acrylonitrile monomer units, and 6 parts by mass of a cross-linked vinyl chloride resin (manufactured by Shin-Etsu Chemical Co., Ltd., GR2500S) were mixed in a blender. The blended materials were kneaded using a φ40 mm single-screw extruder to obtain resin composition 1 for artificial hair fibers in the form of pellets for spinning.

[0053] <Spinning process> The obtained pellet-shaped resin composition for artificial hair fibers was spun using a φ40 mm single-screw melt spinning machine. The discharge rate and winding speed were adjusted to produce undrawn yarn from the molten resin discharged from the nozzle. The cylinder temperature and nozzle temperature of the spinning machine were set to 140 to 180°C.

[0054] <Stretching process and heat treatment process> The obtained undrawn yarn was drawn at 100°C and then annealed at 110°C to obtain raw yarn 1 with a fineness of 45d. The draw ratio was 2.9 times, and the relaxation rate during annealing was 2%. The relaxation rate during annealing is a value calculated by (rotational speed of the take-up roller during annealing) / (rotational speed of the let-off roller during annealing).

[0055] <Shaping process and surface treatment agent application process> The fibers were shaped using a gear machine (NEW YAKI BRAID CRIMPING M / C-2.5mm / SUNG JIN INDUXTRIAL CO.,LTD) under the following conditions: gear width 2.5mm, preheating 90°C, gear roll temperature 90°C, gear roll rotation speed 1m / min. A 1200mm, 120g fiber bundle was created from the processed fibers, and then the fiber bundle was immersed in a surface treatment agent "PEG-1" to adhere the surface treatment agent to the fiber bundle. After thoroughly removing excess surface treatment agent from the fiber bundle, it was dried in an oven at 40°C for 6 hours. The fiber bundle was combed to loosen and arrange it, yielding artificial hair fiber 1.

[0056] (Examples 2 to 15, Comparative Examples 1 and 2) Artificial hair fibers 2 to 17 were obtained in the same manner as in Example 1, except that the compounding composition, raw yarn fineness, draw ratio, type of surface treatment agent, shaping processing conditions, and type of surface treatment agent when preparing the resin composition for artificial hair fibers were as shown in Tables 1 and 2.

[0057] The resins and surface treatment agents used in the examples and comparative examples are as follows. (resin) Vinyl chloride resin: Taiyo PVC Co., Ltd., product name: TH1000 Vinyl copolymer resin: GR-AT-6S (styrene monomer unit 68% by mass, acrylonitrile monomer unit 32% by mass) manufactured by Denka Co., Ltd. Cross-linked vinyl chloride resin A GR2500S: GR2500S manufactured by Shin-Etsu Chemical Co., Ltd. Cross-linked vinyl chloride resin B GR800T: GR800T manufactured by Shin-Etsu Chemical Co., Ltd. Modacrylic resin: Fiber made from vinyl chloride-acrylonitrile copolymer (copolymerization ratio 50:50, weight average molecular weight 80,000-130,000)

[0058] (surface treatment agent) Surface treatment agents having the following compositions were prepared. The composition of each surface treatment agent is shown below. Each surface treatment agent contained the following chemicals per 100 parts by mass of the surface treatment agent, with the remainder being water and a dispersant. PEG-based 1: PEG (polyethylene glycol) 10 parts by weight, alkyl fatty acid ester 0.5 parts by weight PEG system 2: PEG 10 parts by mass Long-chain alkyl cation system 1: 1 part by mass of long-chain alkyl cation Long-chain alkyl cation 2: 2 parts by mass of long-chain alkyl cation Silicone type: 1 part by mass of amino-modified silicone Oil-based: Mineral oil 1 part by mass

[0059] <Characteristics of artificial hair fibers> The properties of the obtained artificial hair fiber bundle were measured by the following methods.

[0060] (Measurement of surface friction resistance, and calculation of delay time δ and dynamic friction coefficient μk) The obtained artificial hair fiber was cut to a 30 cm length to create a 10 g yarn bundle, and a test artificial hair fiber bundle was obtained. Using a sinusoidal motion friction evaluation device, the contactor was moved sinusoidally in a linear direction under the following conditions: a travel distance of 30 mm, a vertical load of 0.98 N (weight 100 g), a rotation speed of 2.1 rad / s, and a maximum speed of 30 mm / s, to measure the surface friction resistance of the test artificial hair fiber bundle and obtain a friction profile. The sinusoidal motion friction evaluation device used was the device described in the following literature. Sano M, Mayama H, Nonomura Y, Friction dynamics of human hair treated with water or cationic surfactant aqueous solution. J Surfact Deterg. 2023;26(2):185-93. https: / / doi.org / 10.1002 / jsde.12634 In addition, the delay time δ that occurs when turning back and forth, calculated from the friction profile, was calculated. The delay time δ was calculated using the following formula (1). δ=Δt / T0 (1) The dynamic friction coefficient μk was also calculated. The dynamic friction coefficient μk was defined as the average value of the friction coefficients that occurred from the time when the static friction coefficient μs was observed until the speed became 0. Here, the static friction coefficient μs was defined as the maximum value of the friction coefficient after the onset of friction before the friction began to decrease.

[0061] (Compression energy WC) Using the above test artificial hair fiber bundle, the compression energy WC was measured at 23° C. and a displacement rate of 1 mm / sec with a compression tester (Kato Tech Co., Ltd., KES-G5).

[0062] (specific volume) The obtained artificial hair fiber was cut to a length of 60 cm to prepare a 120 g fiber bundle. The obtained fiber bundle was placed in a partition with a width of 39.5 mm. The height of the sample was then measured, and the specific volume was calculated based on the following formula. Divider width × sample length × sample height ÷ fiber mass = specific volume (cc / g)

[0063] <Evaluation> The artificial hair fibers of the Examples and Comparative Examples were bundled to a length of 60 mm and a mass of 120 g to prepare artificial hair fibers for evaluation. Eight hair fiber processing technicians (with at least three years of work experience) evaluated the feel of the fibers on a four-point scale from 1 to 4 (4 being the best) for the following aspects: For each aspect, the average of the scores of the eight technicians was rounded to the nearest integer to obtain the evaluation result.

[0064] (volume) When the thread bundle was grasped, the thickness was evaluated on a scale of 1 to 4 (1 being the thinnest and 4 being the thickest).

[0065] (elasticity) The magnitude of the repulsive force when gripping the yarn bundle was evaluated on a scale of 1 to 4 (1 being the smallest repulsive force and 4 being the largest repulsive force).

[0066] (Slip resistance) The ease of slipping when knitting the yarn bundles was evaluated on a scale of 1 to 4 (1 being the most slippery and 4 being the least slippery).

[0067] (Ease of knitting) The ease of knitting the yarn bundles was evaluated on a scale of 1 to 4 (1 being the most difficult and 4 being the most difficult). A yarn bundle that is easy to knit has a moderate smoothness, does not get caught, does not easily come apart, and tends to have a moderate volume and softness.

[0068] (comprehensive evaluation) In the above four evaluations, those that did not include 1 in any of the evaluation criteria were rated as ○, and those that included at least one 1 were rated as ×. Each evaluation is preferably 2 or higher, and more preferably 3 or higher.

[0069] [Table 1]

[0070] [Table 2]

Claims

1. An artificial hair fiber, A 10 g bundle was made from the artificial hair fiber cut to 30 cm to obtain a test artificial hair fiber bundle. Using a sinusoidal motion friction evaluation device, the contactor is sinusoidally moved in a linear direction under the conditions of a moving distance of 30 mm, a normal load of 0.98 N, a rotation speed of 2.1 rad / s, and a maximum speed of 30 mm / s, thereby measuring the surface friction resistance of the test artificial hair fiber bundle and obtaining a friction profile, and the delay time δ calculated from the friction profile is 0.0138 to 0.0200, The delay time δ is expressed by the following formula (1): δ=Δt / 4 ０ ・・・(1) (In equation (1), Δt is the time required from the time when the speed of the contact becomes 0 to the time when the frictional force becomes 0 for the first time, and T ０ indicates the time required for one reciprocation of the sinusoidal motion.)

2. 2. The artificial hair fiber according to claim 1, wherein the dynamic friction coefficient μk obtained by measuring the surface friction resistance of the test artificial hair fiber bundle is 0.150 to 0.

600.

3. The compression energy WC of the test artificial hair fiber bundle is 28.0 to 40.0 gf cm / cm ２ 3. The fiber for artificial hair according to claim 1 or 2, wherein:

4. 3. The artificial hair fiber according to claim 1, wherein the specific volume of the test artificial hair fiber bundle is 5.0 cc / g or more and 25.0 cc / g or less.

5. 3. The artificial hair fiber according to claim 1, wherein the artificial hair fiber contains a polyvinyl chloride resin.

6. A hair accessory comprising the artificial hair fiber according to claim 1 or 2.

Images